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Blunt, penetrating trauma to the ear, nose, and throat, and related structures are striking. Injuries may range from simple soft tissue wounds to complex injuries of the face, neck, and brain. Proximity of the cervical spine and airway complicate anesthetic management. A multidisciplinary approach is required. Airway control has highest priority in initial care. Management of airway, breathing, and circulation need to be tailored to the patient. Decisions regarding airway management, ventilation strategies, monitoring, and fluid and blood administration should be based on the patient’s condition, clinical setting, and the available personnel, expertise, and equipment.

A total of 1318 proteins characterized in the male germ cell Golgi apparatus reveal a new germ cell–specific Golgi marker and a new pan-Golgi marker for all cells. The localization of these and other Golgi proteins reveals differential expression linked to mitosis, meiosis, acrosome formation, and postacrosome Golgi migration and destination in the late spermatid.

Prevention and control of postoperative pain are essential. Inadequate treatment of postoperative pain continues to be a major problem after many surgeries and leads to worse outcomes, including chronic postsurgical pain. Optimal management of postoperative pain requires an understanding of the pathophysiology of pain, methods available to reduce pain, invasiveness of the procedure, and patient factors associated with increased pain, such as anxiety, depression, catastrophizing, and neuroticism. Use of a procedure-specific, multimodal perioperative pain management provides a rational basis for enhanced postoperative pain control, optimization of analgesia, decrease in adverse effects, and improved patient satisfaction.

Estimates of tension leg platform (TLP) surge presented in the literature are generally based on the assumption that the tethers are straight at all times, i.e., that transverse deformations of tethers due to hydrodynamic and inertial forces may be disregarded. The purpose of this note is to verify the validity of this assumption in the case of a deep water TLP. The equation of motion of the tethers for the platform being considered is a nonlinear partial differential wave equation. The numerical solution of that equation showed that, for an assumed harmonic motion of the platform, the hydrodynamic and inertial forces that cause the tethers to deflect will increase the amplitude of the restoring force on the platform by a factor of about three. However, the resulting platform motion does not differ significantly from that corresponding to the assumption that the tethers are straight.

Enamel crystals are unique in shape, orientation and organization. They are hundreds of thousands times longer than they are wide, run parallel to each other, are oriented with respect to the ameloblast membrane at the mineralization front and are organized into rod or interrod enamel. The classical theory of amelogenesis postulates that extracellular matrix proteins shape crystallites by specifically inhibiting ion deposition on the crystal sides, orient them by binding multiple crystallites and establish higher levels of crystal organization. Elements of the classical theory are supported in principle by in vitro studies; however, the classical theory does not explain how enamel forms in vivo. In this review, we describe how amelogenesis is highly integrated with ameloblast cell activities and how the shape, orientation and organization of enamel mineral ribbons are established by a mineralization front apparatus along the secretory surface of the ameloblast cell membrane.

Sulfogalactosylglycerolipid (SGG) is the major sulfoglycolipid of male germ cells. During spermatogenesis, apoptosis occurs in >50% of total germ cells. Sertoli cells phagocytose these apoptotic germ cells and degrade their components using lysosomal enzymes. Here we demonstrated that SGG was a physiological substrate of Sertoli lysosomal arylsulfatase A (ARSA). SGG accumulated in Sertoli cells of Arsa–/–mice, and at 8 months of age, this buildup led to lysosomal swelling and other cellular abnormalities typical of a lysosomal storage disorder. This disorder likely compromised Sertoli cell functions, manifesting as impaired spermatogenesis and production of sperm with near-zero fertilizing ability in vitro. Fecundity of Arsa–/–males was thus reduced when they were older than 5 months. Sperm SGG is known for its roles in fertilization. Therefore, the minimal sperm fertilizing ability of 8-month-old Arsa–/–males may be explained by the 50% reduction of their sperm SGG levels, a result that was also observed in testicular germ cells. These unexpected decreases in SGG levels might be partly due to depletion of the backbone lipid palmitylpalmitoylglycerol that is generated from the SGG degradation pathway in Sertoli cells and normally recycled to new generations of primary spermatocytes for SGG synthesis.

Sulfogalactosylglycerolipid (SGG) is the major sulfoglycolipid of male germ cells. During spermatogenesis, apoptosis occurs in >50% of total germ cells. Sertoli cells phagocytose these apoptotic germ cells and degrade their components using lysosomal enzymes. Here we demonstrated that SGG was a physiological substrate of Sertoli lysosomal arylsulfatase A (ARSA). SGG accumulated in Sertoli cells of Arsa−/−mice, and at 8 months of age, this buildup led to lysosomal swelling and other cellular abnormalities typical of a lysosomal storage disorder. This disorder likely compromised Sertoli cell functions, manifesting as impaired spermatogenesis and production of sperm with near-zero fertilizing ability in vitro. Fecundity of Arsa−/−males was thus reduced when they were older than 5 months. Sperm SGG is known for its roles in fertilization. Therefore, the minimal sperm fertilizing ability of 8-month-old Arsa−/−males may be explained by the 50% reduction of their sperm SGG levels, a result that was also observed in testicular germ cells. These unexpected decreases in SGG levels might be partly due to depletion of the backbone lipid palmitylpalmitoylglycerol that is generated from the SGG degradation pathway in Sertoli cells and normally recycled to new generations of primary spermatocytes for SGG synthesis.

Theubiquitin-proteasome system plays an important role in spermatogenesis. However, the functions of deubiquitinating enzymes in this process remain poorly characterized. We previously showed that the deubiquitinating enzyme USP2 is induced in late elongating spermatids. To identify its function, we generated mice lacking USP2. Usp2 −/−mice appeared normal, and the weights of major organs, including the testis, did not differ from wild type (Usp2 +/+). However, although the numbers of testicular spermatids and epididymal spermatozoa were normal in Usp2 −/−males, these animals had a severe defect in fertility, yielding only 12% as many offspring as Usp2 +/+littermates. Spermatogenesis in Usp2 −/−mice was morphologically normal except for the presence of abnormal aggregations of elongating spermatids and formation of multinucleated cells in some tubules. The epididymal epithelium was morphologically normal in Usp2 −/−mice, but some abnormal cells other than sperm were present in the lumen. Usp2 −/−epididymal spermatozoa manifested normal motility when incubated in culture media, but rapidly became immotile when incubated in PBS in contrast to Usp2 +/+spermatozoa, which largely maintained motility under this condition. Usp2 −/−and +/+spermatozoa underwent acrosome reactions in vitro with similar frequency. In vitro fertilization assays demonstrated a severe defect in the ability of Usp2 −/−spermatozoa to fertilize eggs. This could be bypassed by intracytoplasmic sperm injection or removal of the zona pellucida, which resulted in fertilization rates similar to that of Usp2 +/+mice. We demonstrate for the first time, using mouse transgenic approaches, a role for the ubiquitin system in fertilization.

Formation of tooth enamel is a very complex process in which a specific set of proteins secreted by ameloblasts play a primordial role. As part of a screening procedure to identify novel proteins secreted by EO (enamel organ) cells of rat incisors, we isolated a partial cDNA fragment (EO-017) that is the homologue of the recently described mouse Amtn (amelotin) gene [Iwasaki, Bajenova, Somogyi-Ganss, Miller, Nguyen, Nourkeyhani, Gao, Wendel and Ganss (2005) J. Dent. Res. 84, 1127–1132]. Presented herein is the cloning of rat and pig full-length cDNAs with their deduced protein sequences. Detailed expression profiling by Northern-blot analysis and RT (reverse transcriptase)–PCR on rat and mouse tissues revealed highest expression in the mandible, more specifically in the maturation stage of the EO. Among all tissues tested, low expression was detected only in periodontal ligament, lung, thymus and gingiva. In silico analyses revealed that the Amtn gene is highly conserved in seven other mammals, but is absent from fish, birds and amphibians. The Amtn protein is enriched in proline, leucine, glutamine and threonine (52% of total) and contains a perfectly conserved protein kinase CK2 phosphorylation site. Transient transfection experiments in HEK-293 cells (human embryonic kidney cells) showed that secreted Amtn is post-translationally modified possibly through O-linked oligosaccharides on threonine residues. In concordance with its predominant expression site, immunofluorescence localization within the rat and mouse mandibles revealed Amtn localized to the basal lamina of maturation stage ameloblasts of incisors and unerupted molars. Intense Amtn protein expression was also detected in the internal basal lamina of junctional epithelium in molars. The peculiar and unique cellular localization of Amtn suggests a role in cell adhesion.

The formation rates of mineral in developing enamel were determined by microweighing of incisors of mice and rats. Computations indicated that a large excess of hydrogen ions would result from creating apatite at the calculated rates. Enamel organ cells (ameloblasts), therefore, likely excrete bicarbonate ions to prevent pH in fluid bathing enamel from becoming too acidic.

The formation rates of mineral in developing enamel were determined by microweighing of incisors of mice and rats. Computations indicated that a large excess of hydrogen ions would result from creating apatite at the calculated rates. Enamel organ cells (ameloblasts), therefore, likely excrete bicarbonate ions to prevent pH in fluid bathing enamel from becoming too acidic.Introduction:Protons (H+) are generated whenever calcium and phosphate ions combine directly from aqueous solutions to form hydroxyapatite. Enamel is susceptible to potential acid loading during development because the amount of fluid bathing this tissue is small and its buffering capacity is low. The epithelial cells covering this tissue are also believed to form permeability barriers at times during the maturation stage when crystals grow at their fastest rates. The goal of this study was to measure the bulk weight of mineral present in rodent enamel at specific times in development and estimate the amount of acid potentially formed as the apatite crystals mature.Materials and Methods:Upper and lower jaws of mice and rats were freeze‐dried, and the enamel layers on the incisors were partitioned into a series of 0.5 mm (mouse) or 1.0 mm (rat) strips along the length of each tooth. The strips were weighed on a microbalance, ashed at 575°C for 18–24 h to remove organic material, and reweighed to determine the actual mineral weight for each strip.Results and Conclusions:The data indicated that, despite differences in gross sizes and shapes of maxillary and mandibular incisors in rats and mice, the overall pattern and rates of mineral acquisition were remarkably similar. This included sharply increasing rates of mineral acquisition between the secretory and maturation stages, with peak levels approaching 40 μg/mm tooth length. Computer modeling indicated that quantities of H+ions potentially generated as apatite crystals grew during the maturation stage greatly exceeded local buffering capacity of enamel fluid and matrix proteins. In other systems, bicarbonate ions are excreted to neutralize highly acidic materials generated extracellularly. Data from this study indicate that ameloblasts, and perhaps cells in other apatite‐based hard tissues, use similar bicarbonate release mechanisms to control excess acid arising from mineral formation.

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Purpose: Cricoid pressure is commonly used during rapid sequence induction and intubation to minimize the risk of aspiration. The objective of the study was to evaluate the ease of fibreoptic (WuScope System™) intubation in anesthetized adults receiving cricoid pressure. Methods: The intubation difficulty scale (IDS) was used to measure tracheal intubation difficulties in 33 patients undergoing elective surgery with general anesthesia and complete neuromuscular blockade. Each patient had their trachea intubated under two conditions: with and without cricoid pressure. The order of conditions was determined randomly. Cricoid pressure was applied by an experienced anesthesia provider. Main results: An IDS value of 0 (ideal intubation, that is one performed by the first operator on the first attempt, using the first technique with full visualization of the glottis and no vocal cord compression) occurred in 30 of 33 patients (91%) without cricoid pressure and in 22 of 33 patients (67%) with cricoid pressure (P < 0.05). Cricoid pressure compressed the vocal cords in nine patients (27%) and impeded tracheal tube placement in five ( 15%). In three patients (9%), pressure had to be released in order to successfully intubate. Conclusion: Cricoid pressure may impede or even prevent fibreoptic laryngoscopic intubation with the WuScope System™.

Aliphatic and aromatic components in formulated jet fuels can cause occupational dermatitis. However, the influence of JP-8 performance additives (DIEGME, 8Q21, and Stadis450) on the dermal disposition of fuel components is not well understood. These additives are formulated with commercial Jet-A to form military JP-8 fuel. The purpose of this study is to assess the influence of these additives on the dermal disposition of marker aromatic and aliphatic components, naphthalene and dodecane, respectively. Porcine skin sections in an in vitrosystem were used to characterize chemical–biological interactions that modulate diffusion of jet fuel components and isolated perfused porcine skin flaps (IPPSFs) were used to evaluate diffusion in a viable skin model with an intact microvasculature. In these 5-h studies, Jet-A, Jet-A + DIEGME, Jet-A + 8Q21, and Jet-A + Stadis450, Jet-A + DIEGME + 8Q21, Jet-A + DIEGME + Stadis450, Jet-A + 8Q21 + Stadis450, and JP-8 mixtures were tested. In general, naphthalene absorption (0.76–2.39% dose) was greater than dodecane absorption (0.10–0.84% dose), while the IPPSFs alone demonstrated that dodecane absorption was significantly greater in JP-8 than in Jet-A. Synergistic interactions with 8Q21 + Stadis450 appear to enhance systemic absorption of either naphthalene or dodecane, while DIEGME + Stadis450 increased naphthalene (1.88% dose) and dodecane (2.02% dose) penetration into the skin and fat tissues of IPPSFs. These findings were supported by the fact that 8Q21 + Stadis450 significantly increased dodecane flux and permeability in porcine skin sections, but 8Q21 alone reduced marker diffusion in both membrane systems. Furthermore, dodecane is more likely than naphthalene to remain in the stratum corneum and skin surface at 5 h, and DIEGME mixtures played a significant role in skin and surface retention of both markers. In summary, the data suggest that various combinations of these three performance additives in JP-8 can potentially alter the dermal disposition of aromatic and aliphatic fuel components in skin. More importantly, products of two-factor interactions were not predictable from single-factor exposures and, by extension, cannot be extrapolated to three-factor interactions.

Rapid-sequence induction and intubation (RSI) is a technique that is designed to provide optimal tracheal intubating conditions and reduce the risk of pulmonary aspiration. RSI has a higher success rate, fewer complications, and better outcome compared with orotracheal intubation without neuromuscular relaxants and blind nasotracheal intubation. Before considering performing RSI, the clinician must ensure that intubation is predicted to be successful based on assessment of the airway. Failure to intubate and subsequent inability to ventilate can lead quickly to death or cerebral hypoxia and brain injury. Maximal preoxygenation can be attained by providing 100 oxygen through a sealed system for 3 to 5 minutes of normal tidal volume ventilation or by hyperventilation with 8 deep breaths of 100 oxygen within 60 seconds. Cricoid pressure prevents passive regurgitation of stomach contents and reduces the risk of gastric insufflation during bag-mask ventilation. Cricoid pressure can also distort upper airway anatomy and make glottic visualization more difficult or impossible. Brief release of cricoid pressure or external laryngeal manipulation and depression of the thyroid cartilage often improves the view at direct laryngoscopy. The use of neuromuscular relaxants to facilitate intubation is associated with side effects regardless of whether depolarizing (e.g., succinylcholine) or nondepolarizing (e.g., rocuronium or rapacuronium) agents are used. Avoidance of relaxants, however, results in inferior intubating conditions unless large doses of induction agents and opioids are given. Tracheal intubation aids such as the gum elastic bougie are useful whenever difficult glottic visualization occurs. The bougie is relatively easy to insert through the glottic opening when only the epiglottis (grade III view) or tip of the arytenoids (grade II view) can be visualized. The tracheal tube is then threaded over the bougie and tracheal placement is confirmed using capnography. Special laryngoscopes, such as the Bullard, WuScope, and McCoy, and lighted stylets are also valuable for facilitating difficult intubation. The short learning curve with the McCoy hinged-blade tip is of obvious benefit. Contingency plans for failed intubation include use of the laryngeal mask airway (LMA), Combitube, and cricothyrotomy.

A patent, unobstructed airway is fundamental in the care of the trauma patient, and is most often obtained by placing a cuffed tube in the trachea. The presence of shock, respiratory distress, a full stomach, maxillofacial trauma, neck hematoma, laryngeal disruption, cervical spine instability, and head injury all combine to increase tracheal intubation difficulty in the trauma patient. Complications resulting from intubation difficulties include brain injury, aspiration, trauma to the airway, and death. The use of devices such as the gum-elastic bougie, McCoy laryngoscope, flexible and rigid fiberscopes, intubating laryngeal mask, light wand, and techniques such as rapid-sequence intubation, manual in-line axial stabilization, retrograde intubation, and cricothyroidotomy, enhance the ability to obtain a definitive airway safely. The management of the failed airway includes calling for assistance, optimal two-person bag-mask ventilation, and the use of the laryngeal mask airway, Combitube, or surgical airway. The simulation of airway management using realistic simulator tools (e.g. full-scale simulators, virtual reality airway simulators) is a promising modality for teaching physicians and advanced life support personnel emergency airway management skills.

Adverse consequences of perioperative hypothermia include myocardial ischemia, cardiac arrhythmias, coagulopathy, shivering, increased oxygen consumption during rewarming, alteration in drug metabolism, impaired offloading of oxygen from hemoglobin, and increased wound infection. Administration of cold or inadequately warmed intravenous fluids contributes to hypothermia, whereas administration of normothermic fluids may reduce both the incidence and complications of hypothermia. Infusion of adequately warmed fluids is mandatory in trauma patients requiring fluid resuscitation to minimize thermal stress and maintain thermal homeostasis.

Success in caring for the bleeding trauma patient requires rapid evaluation and treatment to ensure adequate tissue perfusion. Thermally efficient fluid warmers, effective transfusion services, and rapid availability of coagulation tests are practical aspects of trauma resuscitation that cannot be overlooked. Critically important management issues include preventing hypothermia, recognizing and treating complications of massive transfusion, and optimizing vital signs, urinary output, central venous pressures, base deficit, lactate, cardiac output, mixed venous oxygen saturation, and organ function

Amelogenins represent the major component of the organic matrix of enamel, and consist of several intact and degraded forms. A precise knowledge of their respective distributions throughout the enamel layer could provide some insight into their functions. To date, no antibody exists that can selectively detect the secretory forms of amelogenin. In this study we used the chicken egg yolk system to generate an antibody to recombinant mouse amelogenin. Immunoblots of whole homogenates from rat incisor enamel organs and enamel showed that the resulting antibody (M179y) recognized proteins corresponding to the five known secretory forms of rat amelogenin. Immunogold cytochemistry demonstrated that reactivity was restricted to ameloblasts and enamel. Secretory forms of amelogenin persisted in significant amounts throughout the enamel layer. The density of labeling was highest over the surface portion of the enamel layer, but enamel growth sites in this region showed a localized paucity of gold particles. Immunoreactivity was lowest over the mid-portion of the layer and increased moderately near the dentino–enamel junction. These results indicate that intact forms of amelogenin probably have a more complex distribution in the enamel layer than was heretofore suspected.

Protease-activated receptor-2 (PAR-2) is a tethered-ligand, G-protein-coupled receptor that is activated by proteolytic cleavage or by small peptides derived from its cleaved N-terminal sequence, such as SLIGRL-NH2. To assess specific PAR activity, we developed an immortalized murine PAR-1 (−/−) cell line transfected with either human PAR-2 or PAR-1. A “directed” library of more than 100 PAR agonist peptide analogues was synthesized and evaluated for PAR-2 and PAR-1 activity to establish an in-depth structure-function profile for specific action on PAR-2. The most potent agonist peptides (EC50 = 2–4 μM) had Lys at position 6, Ala at position 4, and pFPhe at position 2; however, these also exhibited potent PAR-1 activity (EC50 = 0.05–0.35 μM). We identified SLIARK-NH2 and SL-Cha-ARL-NH2 as relatively potent, highly selective PAR-2 agonists with EC50 values of 4 μM. Position 1 did not tolerate basic, acidic, or large hydrophobic amino acids. N-Terminal capping by acetyl eliminated PAR-2 activity, although removal of the amino group reduced potency by just 4-fold. At position 2, substitution of Leu by Cha or Phe gave equivalent PAR-2 potency, but this modification also activated PAR-1, whereas Ala, Asp, Lys, or Gln abolished PAR-2 activity; at position 3, Ile and Cha were optimal, although various amino acids were tolerated; at position 4, Ala or Cha increased PAR-2 potency 2-fold, although Cha introduced PAR-1 activity; at position 5, Arg or Lys could be replaced successfully by large hydrophobic amino acids. These results with hexapeptide C-terminal amides that mimic the native PAR-2 ligand indicate structural modes for obtaining optimal PAR-2 activity, which could be useful for the design of PAR-2 antagonists.

Hypothermia may be encountered during the management of severely injured patients, and with exception of deliberate hypothermia for neuroprotection, has been associated with increased morbidity and mortality. This review examines the recent literature with regard to risk factors for developing hypothermia, significance of hypothermia, therapeutic use of hypothermia, and invasive and noninvasive methods to prevent and treat hypothermia.

Purpose:Proper care of the trauma patient often includes tracheal intubation to insure adequate ventilation and oxygenation, protect the airway from aspiration, and facilitate surgery. Airway management can be particularly complex when there are facial bone fractures, head injury and cervical spine instability.

Dermal exposure to jet fuels has received increased attention with the recent release of newer fuels with novel performance additives. The purpose of these studies was to assess the percutaneous absorption and cutaneous disposition of topically applied (25 μl/5 cm2) neat Jet-A, JP-8, and JP-8(100) jet fuels by monitoring the absorptive flux of the marker components 14C naphthalene and 3H dodecane simultaneously applied nonoccluded to isolated perfused porcine skin flaps (IPPSF) (n= 4). Absorption of 14C hexadecane was estimated from JP-8 fuel. Absorption and disposition of naphthalene and dodecane were also monitored using a nonvolatile JP-8 fraction reflecting exposure to residual fuel that might occur 24 h after a jet fuel spill. In all studies, perfusate, stratum corneum, and skin concentrations were measured over 5 h. Naphthalene absorption had a clear peak absorptive flux at less than 1 h, while dodecane and hexadecane had prolonged, albeit significantly lower, absorption flux profiles. Within JP-8, the rank order of absorption for all marker components was (mean ± SEM % dose) naphthalene (1.17 ± 0.07) > dodecane (0.63 ± 0.04) > hexadecane (0.18 ± 0.08). In contrast, deposition within dosed skin showed the reverse pattern. Naphthalene absorption into perfusate was similar across all fuel types, however total penetration into and through skin was highest with JP-8(100). Dodecane absorption and total penetration was greatest from JP-8. Absorption of both markers from aged JP-8 was lower than other fuels, yet the ratio of skin deposition to absorption was greatest for this treatment group. In most exposure scenarios, absorption into perfusate did not directly correlate to residual skin concentrations. These studies demonstrated different absorption profiles for the three marker compounds, differential effects of jet fuel types on naphthalene and dodecane absorption, and uncoupling of perfusate absorption from skin disposition.

Vimentin, an intermediate filament component, has been identified in many mesenchymal cells by a variety of LM and EM immunolabeling techniques. In our study, several tissue-processing conditions and monoclonal and polyclonal antibodies against vimentin were screened for immunostaining of rat incisor odontoblasts. Using postembedding colloidal gold immunocytochemistry, we were unable to detect any convincing vimentin antigenicity in these cells, but one of the monoclonal antibodies (V9-S) unexpectedly resulted in intense labeling over intra- and extracellular compartments that normally are strongly immunoreactive with anti-amelogenin antibodies. Blocking experiments showed that V9-S binding was competed by anti-amelogenin antibody. Immunoblots indicated that enamel proteins reacted with this anti-vimentin antibody after fixation with glutaraldehyde. These data suggest that the observed immunoreaction is directed against an epitope apparently created by crosslinking of enamel proteins during fixation. Although the labeling cannot be considered specific, it is nevertheless selective because it is very precisely localized over compartments containing enamel proteins and shows no binding to other calcified dental tissues, including dentin and bone. The V9-S antibody can therefore be used as a reliable probe to identify the presence and distribution of amelogenins in fixed tissues.

Moment recursion relations have previously been derived for the stationary probability density functions of continuous-time stochastic systems with Wiener (white noise) input. These results are extended in this paper to the case of Poisson (shot noise) input. The non-linear dynamical systems are expressed, in general, as stochastic differential equations, with an independent increment input. The transition probability density function evolves according to the appropriate Kolmogorov equation. Moments of the stationary density are obtained from the Fourier transform of the stationary density. The moment relations can be used to estimate the parameters of linear and non-linear stochastic systems from empirical moments, given either Wiener or Poisson input.

Purpose: To determine the relative efficacy of heat conservation and convective warming in maintaining penoperative normothermia. (central temperature ≥36°C). Methods: Thirty-seven patients undergoing elective gynaecological, orthopaedic, or general surgery scheduled to last two hours were prospectjvely studied. Patients were randomized to one of two groups. Group I patients received heat conservation with reflective blankets (Thermadrape™, Vital Signs, Inc., Totowa, NJ) applied preoperatively and warmed iv fluids (Hotline™ SIMS Level I Technologies, Inc, Rockland, MA). Group 2 patients received convective warming (BairHugger, Augustine Medical, Inc., Eden Prairie, MN) after induction of anaesthesia andivfluids at room temperature. All patients received general anaesthesia with isoflurane. Tympanic membrane and forearm-fingertip skin temperature gradients were measured penoperatively at 15 min intervals. Results: Central temperature decreased after induction to a minimum level of 35.9 ± 0.1°C in group I and 36.0 ± 0.1°C in group 2 and then increased towards pre-induction values in group 2, and were higher (P < 0.05) than in group 1: 95% group 2 patients had central temperature ≥ 36.0°C at the end of surgery (vs 69% of group l.P< 0.05). During the first 30 mm in PACU, central temperatures were higher in group 1 than in group 2 (36.8 ± 0.1°C vs 36.2 ± 0.2°C. P<0.05). After 60 mm, central temperatures were similar (36.8°C). The incidence of shivering and degree of penpheral cutaneous vasoconstnction were also similar. Conclusion: Patients receiving convective warming were more likely to leave the operating room normothermic. and had higher central temperatures dunng the first 30 mm in the recovery room. The intergroup temperature differences were small, and by 60 min, had disappeared.

Purpose: To evaluate tapes and taping methods with respect to the minimum force required to dislodge endo tracheal tubes (ETTs). Methods: A simulated face model consisting of a section of PVC pipe was used. The ETT was attached to a piezo-electric force transducer and pullout force was manually applied in a vertical, right or left direction. Five tape types were tested: Curity. Leukosilk, Hy.tape. Leukopore, and Transpore. Seven taping methods were used to secure the ETT The methods differed with respect to tape width and whether the tape was split along its longitudinal axis. Each taping condition was replicated 20 times (7 methods x 3 tapes x 3 directions) for a total of 2100 pullout tests. Results: Minimum forces to dislodge ETTs were higher (P < 0.05) with Cunty tape (mean ± SD: 135 ± 75 N) than with the other tapes (Leukosilk: 93 ± 51 N, Hy.tape: 78 ± 34 N, Leukopore: 47 ± 32, and Transpore: 37 ± 23 N). The most secure taping method was achieved by taping the ETT, using 2.5 cm wide Cunty tape, in a circumferential fashion to both the upper and lower borders of the simulated mouth opening, and reinforcing these tapes with two strips applied longitudinally across the borders of the mouth opening (method 7). Taping methods which involved splitting the tape along its longitudinal axis resulted in lower minimal pullout forces when-ever the pullout force was directed towards the side of attachment (P< 0.05vsright and vertical direction). Conclusion: There are differences in ETT pullout forces and mechanisms of dislodgement depending on taping method and tape type.

The potency of atracurium was determined in five patients with moderate to severe generalized myasthenia gravis undergoing thymectomy. Train-of-four stimulation was applied to the ulnar nerve and the force of contraction of the adductor pollicis was measured. Cumulative dose-response curves were obtained during thiopentone-nitrous oxide-fentanyl anaesthesia. The average time to complete the dose-response studies was 12.7 ± 1.5 minutes. The ED50, ED90 and ED95 of atracurium were (mean ± SEM) 0.07 ± 0.01, 0.12 ± 0.22, and 0.14 ± 0.04 mg · kg− 1, respectively. The time to 25 per cent first twitch recovery was 35 ± 4 min following maximum blockade. Ten normal patients were studied in the same manner. Their ED50, ED90 and ED95 were 0.13 ± 0.01, 0.21 ± 0.02 and0.24 ± 0.03 mg · kg− 1, respectively. These results demonstrated that, in patients with moderate to severe generalized myasthenia gravis, atracurium was 1.7–1.9 times as potent as in normal individuals.

The effect of age on the onset and duration of action of a d-tubocurarine (DTC) neuromuscular blockade with and without pancuronium priming in children was examined. Sixty ASA physical status I or II patients in three age ranges (0-1 yr, 1 -3 yr and 3-10yr) were anaesthetized with thiopentone, halothane and nitrous oxide. Each patient received either a single paralyzing dose of DTC 0.4 mg·kg-1, or DTC 0.36 mg·kg-1preceded three minutes earlier by pancuronium 0.007 mg·kg-1. Evoked force of contraction of the adductor pollicis was measured using train-of-four stimulation applied every 12 sec. Time to 90 per cent first twitch depression after a single dose of DTC increased with increasing age (r = 0.65, p < 0.01), and was 1.6 min (SEM ± 0.3) in the 0-1 yr group, 1.9 ± 0.3 min (1-3 yr), and 5.2 ±1.2 min (3-10 yr). Time to ten per cent spontaneous recovery after single dose DTC was shorter in older individuals (r = 0.40, p < 0.05), being 36.4 ±5.1 min in infants 0-1 yr, 30.6 ±4.6 min (1-3 yr), and 24.0 ± 2.7 min (3-10 yr). Priming with pancuronium accelerated the onset significantly in all age groups with 90 per cent T1depression occurring at 0.7 ± 0.1 min (0-1 yr), 0.9 ± 0.1 min (1-3 yr), and 2.1 ± 0.6 min (3-10 yr). However, priming delayed recovery, especially in infants. Times to ten per cent spontaneous recovery following DTC with pancuronium priming were 71.0 ± 8.1 (0-1 yr), 42.7 ±3.8 (1-3yr), and29.3 ±3.9 min (3-10 yr). It is concluded that onset and recovery from a DTC blockade are markedly age-related, and this relationship may be accentuated by pretreatment with pancuronium.

To evaluate the response of the hypothalamic-pituitary-testicular axis to surgery, serum levels of gonadotropins and steroid hormones were measured prior to and after elective surgery in men under age 50. Twelve men having surgery under general anesthesia had significant decreases in serum testosterone levels after surgery (P<0.02). Six men having surgery under spinal or local anesthesia did not show a significant reduction in serum testosterone. By the 2nd postoperative day, the magnitude of the decreases in serum testosterone and serum free testosterone were similar (23% and 25%, respectively) in men having surgery under general anesthesia, and the changes in serum testosterone and serum free testosterone were significantly correlated (r=0.69, P<0.02). In subjects having general anesthesia, serum levels of estradiol, androstenedione, and 17-hydroxyprogesterone tended to fall, although not significantly, while serum follicle-stimulating hormone and the testosterone to estradiol ratio did not change. Serum luteinizing hormone (LH) levels increased by a mean of 19% after surgery under general anesthesia, although this increase was not statistically significant. The concomitant fall of serum testosterone and serum free testosterone after surgery under general anesthesia suggested that this fall is due to a decrease in testosterone secretion rather than a primary change in testosterone clearance or serum binding of testosterone. This decrease in testosterone secretion was not due to a specific block in the distal steps of testosterone biosynthesis nor to hypothalamic-pituitary suppression by elevated estradiol levels. The nonsignificant increase in serum LH is consistent with either a primary testicular defect or hypothalamic-pituitary dysfunction as the cause of the fall in serum testosterone after surgery under general anesthesia.

• Hyperthyroidism may be caused by the inappropriate secretion of thyroid-stimulating hormone (TSH) from a pituitary tumor. Of 33 reported cases, 17 have occurred in women and 16 have occurred in men. All patients had large tumors, and secretion of a second hormone (growth hormone or prolactin) has been common. Diagnosis requires the detection of TSH in the serum when patients are clinically and biochemically hyperthyroid. Ancillary tests supporting the diagnosis includean α-subunit to TSH molar ratio greater than 1.0, an absent TSH response to protirelin, suppression of serum TSH (but not α-subunit) by glucocorticoids, and a lack of suppression of serum TSH by dopaminergic agonists. Successful treatment of this disorder requires pituitary surgery and/or pituitary irradiation.(Arch Intern Med 1983;143:503-507)

The effects of propranolol and hemodilution on myocardial performance and oxygen delivery were evaluated in 36 anesthetized rats. Oral propranolol treatment consisted of 64 mg/kg/d for 6 weeks prior to the experiments, whereas intravenous (IV) propranolol treatment consisted of 5 μ/kg/ min for 60 minutes after hemodilution. The hematocrit was reduced to 20% by a hetastarch-for-blood exchange. Animals were divided into six equal groups as follows: (1) no oral drug (water), no hemodilution, no IV drug (saline); (2) oral water, hemodilution, IV saline; (3) oral water, no hemodilution, IV propranolol; (4) oral water, hemodilution, IV propranolol; (5) oral propranolol, no hemodilution, IV saline; and (6) oral propranolol, hemodilution, IV saline. Left ventricular (LV) pressures, maximal dP/dt, ascending aortic blood flow, and response to preload (peak cardiac and stroke volume indices) and afterload (LV-developed pressure) stress were measured. In group 2, hemodilution significantly increased cardiac index, stroke volume index, and dP/dt, and decreased blood pressure, peripheral resistance, and oxygen delivery compared with group 1. Compared with group 2, IV propranolol after hemodilution in group 4 significantly decreased cardiac index, dP/dt, LV-developed pressure, and peak cardiac index, and increased peripheral resistance. Stroke volume index and peak stroke volume index after preload stress remained elevated in group 4, despite the negative inotropic effects of IV propranolol. Oral propranolol in group 6 did not prevent the hemodilution-induced increase in stroke volume index and peak stroke volume index in response to preload stress, although it did decrease cardiac index and dP/dt compared with group 2. Oxygen delivery was reduced in the hemodiluted animals in proportion to the decrease in hemoglobin, regardless of propranolol treatment. It is concluded that reduced myocardial contractility and cardiac performance by nonselective pharmacological β-adrenoceptor blockade does not interfere with the compensatory increase in stroke volume index after hemodilution.

Abstract:  The Golgi apparatus of epididymal principal cells shares many structural features with other cell types. Saccular regions are arranged in a cis-Golgi network, eight flattened saccules, and several trans-Golgi networks (TGNs). Dilated tubules form intersaccular connecting regions which joint together saccules at the same or different levels between adjacent stacks. Wells exist as large perforations in register with the four cis-most saccules and serve as areas of vesicular interactions. TGNs are variable and can appear to peel off the stack or to be detached from it in the form of an anastomotic tubular network with pale dilated areas corresponding to prosecretory granules connected by short narrow bridges. Elongated or discoid dilated cisternae of endoplasmic reticulum (ER) (sparsely granulated) lie over the cis face of the stack, from which they are separated by an intermediate compartment filled with vesicles and tubules. The ER is also closely juxtaposed to the TGNs and the eighth saccule but interconnections are never seen between them. Vesicles of the COP variety reside at all levels of the stack and appear to bud off the cis-located ER and the edges of the saccules, while clathrin-coated vesicles appear mainly on the trans face of the stack and next to lysosomes. In the supranuclear cytoplasm, clusters of vesicles and tubules, at times budding off enveloping ER, appear to radiate toward the Golgi stacks where they fuse with cis Golgi elements. Taken together, these observations suggest dynamic functions and interactions for the various Golgi elements, associated vesicles, ER, and vesicular tubular clusters.

The study evaluated the warming ability and flow rates associated with four fluid warming devices during pressure driven infusion and during wide open gravity driven roller clamp infusion. Warmers tested were the Astotherm, Flotem IIe, Level 1 System 250 and a modified cardioplegia heat exchanger. Fluids tested were crystalloid, red cells diluted with 200 ml, 0.9% saline, and undiluted red cells. The volume of fluid and outlet temperatures (point where iv tubing would be attached to the patient) were measured for each fluid and compared among warmers for each flow rate condition. For pressure driven infusion of red cells and crystalloid, the System 250, and modified heat exchanger delivered warmer fluids (33-35° C) at higher flow rates (160–740 ml · min− 1) than the Astotherm and Flotem (23–31° C, 44–268 ml · min− 1, P< 0.05). For gravity driven infusion, the System 250 delivered the warmest fluids (33–36° C, P < 0.05) compared with the modified heat exchanger (29–35°C), Astotherm (26–32°C) and Flotem (26–27° C). In conclusion, the modified heat exchanger and System 250 were moderately effective (outlet temperture >32°C) in warming crystalloid and red cells at pressure driven flow rates. Only the System 250 warmed red cells >35° C at gravity driven flow rates. The Flotem and Astotherm were not effective in warming rapidly infused solutions. None of the warmers tested was able to deliver fluids at normothermia (>36.5° C).

The purpose of the study was to compare the relative effectiveness of several combinations of tapes and taping methods with respect to the force required to pull out intravenous catheters. A simulated forearm model consisting of a section of firm PVC pipe was used for the first and second series of experiments. In the third experiment, one method of taping catheters was compared in the PVC model and in volunteers. Pull-out forces were measured with a force transducer and recorded on paper. In the first experiment, catheters secured with Curity tape resisted pullout to a greater extent than those with Transpore tape and provided approximately twice the force advantage (P < 0.05). In the second experiment using Curity tape, minimum forces to dislodge the catheters were (means ± SD) 53 ± 13, 82 ± 13, 113 ± 29, 124 ± 24, 176 ± 29 and 141 ± 46 N, for methods 1–6, respectively. In the third series, the minimum pullout forces were higher for Curity than with Transpore tape for both the human and simulated PVC forearm surfaces (63 ± 11 and 55 ± 12 N vs 52 ± 7 and 44 ± 12 N, P < 0.01), and the pullout forces were higher for the simulated vs the human skin surface for both tape types (P < 0.01). Compared with Curity tape, Transpore tape was more likely to fail by tape fracture in both the simulated and human skin surfaces (P < 0.05). The data suggest that there are important differences in pullout forces and mechanisms of dislodgement depending on taping method and tape type. Curity tape, using method 5 or 6, was superior to Transpore tape and the other taping methods in resisting pullout.

The study evaluated the effects of different techniques used to secure intravenous (iv) catheters. An angiocatheter attached to standard iv tubing was taped to human forearm using a standard taping method. A calibrated piezoelectric force transducer was attached to the iv tubing. The force applied along the longitudinal axis to pull out the taped catheter was measured and recorded on paper. Three tape types, Curity, Leukopor and Transpore, were evaluated alone, with benzoin skin pretreatment and with mastisol pretreatment. A randomized 3 × 3 block design with 20 replications per block was utilized, and a total of 180 pullout tests were performed on two adult volunteers. Without pretreatment, the forces required to dislodge catheters were (means ± SEM) 46 ± 2, 37 ± 2 and 38 ± 2 Newtons for Curity, Leukopor and Transpore tape, respectively. Corresponding values for mastisol pretreatment (64 ± 1,64 ± 3 and 52 ± 3 Newtons) were greater (P < 0.05) for each tape compared with benzoin (54 ± 3, 53 ± 2 and 40 ± 2 Newtons) and no pretreatment. The most frequent failure mode for Transpore tape was by tape fracture, for Curity tape was by separation from the skin of tape and catheter as a single unit, and for Leukopor tape was by catheter separation while tape remained attached to skin (P < 0.001). The data suggest that the application of mastisol prior to taping iv catheters with Curity or Leukopor tape helps to minimize the risk of accidental dislodgement.

The purpose of the study was to determine the effect of non-depolarizing muscle relaxants and waiting time on muscle fasciculations after succinylcholine in anaesthetized patients. Adult men and women, 60–80 kg, received pretreatment doses of atracurium 5 mg (n = 160), pancuronium 1 mg (n = 123), d-tubocurarine 3 mg (n = 97), or vecuronium 1 mg (n = 62). Waiting times between pretreatment and succinylcholine, 100 mg, ranged between 0.6 and 5 min. Data points (presence or absence of fasciculations and waiting time) were entered for each patient. Waiting time response curves were obtained between the logit transformation of the probability of no fasciculations and the log waiting time for each drug. Statistical differences between wait time response curves were determined by non-overlapping of the associated 95% confidence intervals. The frequency of muscle fasciculations was reduced with increased waiting time for all nondepolarizers tested. Following wait times of three, four and five minutes, the probability of not fasciculating was greatest with d-tubocurarine (90, 97 and 99%, respectively) and atracurium (89, 93 and 96%). Corresponding values for pancuronium were 70, 82 and 88% and for vecuronium were 74, 82 and 86% Waiting times to prevent fasciculations in 80% and 90% of patients were shorter with d-tubocurarine (2.46 and 3.02 min, respectively) or atracurium (2.16 and 3.24 min) than pancuronium (3.77 and 5.35 min) or vecuronium (3.73 and 6.36 min). In a subgroup of 107 patients who did not fasciculate after succinylcholine, patients receiving d-tubocurarine pretreatment had the lowest frequency of coughing/bucking responses during tracheal intubation (22%), whereas patients receiving atracurium had the highest frequency (58%). The data suggest that pretreatment with d-tubocurarine 3 mg, using a 3.5 to 4 min wait time interval is the optimal method to prevent succinylcholine-induced fasciculations.