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Background: The concurrence of multiple sclerosis (MS) and brain tumors is a rare but well-recognized condition. The radiologic evidence of the progressive evolution of a mega-plaque in a tumor has never been described. We report the first case of such an occurrence., Methods: A 27-year-old woman with a diagnosis of MS was referred to us for an intense frontal headache. Magnetic resonance imaging showed a mass lesion in correspondence of a black hole lesion previously diagnosed. The patient was operated on, with complete removal of the tumor documented by an intraoperative MRI. The histologic examination evidenced an ependymoma. Postoperative radiotherapy was performed., Results: The patient is well and recurrence-free at 2 years follow-up., Conclusions: The present case, documenting the transformation of a mega-plaque into a tumor, suggests a cause-effect relationship between MS and brain tumors.

The tumor suppressor gene CDKN1B encodes for a 27-kDa cyclin-dependent kinase inhibitory protein, p27Kip1, which together with its well-established role in the inhibition of cell proliferation, displays additional activities in the control of gene transcription and cell motility. p27Kip1 thus represents a good candidate for a gene therapy approach, especially in those cancers refractory to the conventional therapies, like human glioblastoma. Here, we show that overexpression of p27Kip1 in glioblastoma cell lines induced cell cycle arrest and inhibition of cell motility through extracellular matrix substrates. The use of adenoviral vectors in the treatment of glioblastoma in vivo showed that p27Kip1 was able to block not only cancer cell growth but also local invasion and tumor-induced neoangiogenesis. The latter effect was due to the ability of p27 to impair both endothelial cell growth and motility, thus preventing proper vessel formation in the tumor. The block of neoangiogenesis depended on cytoplasmic p27Kip1 antimigratory activity and was linked to its ability to bind to and inhibit the microtubule-destabilizing protein stathmin. Our work provides the first evidence that a successful p27Kip1-based gene therapy is linked to tumor microenvironment modification, thus opening new perspectives to the use of gene therapy approaches for the treatment of refractory cancers.

New forms of cancer chemotherapy are tested in therapeutic trials (phase I, phase II or phase III) while chemotherapeutic agents whose efficacy has already been demonstrated are used, in routine clinical practice, in the context of protocols. The overall survival rate is the best objective parameter of efficacy of the treatments tested, but this parameter is obtained too late, as the effect on the tumour must be determined as soon as possible in order to institute another treatment if necessary. Tumour response, or objective response, is based on changes in the number and size of measurable primary or secondary tumour "targets". These parameters are obtained more rapidly than survival data, but their reliability is highly dependent on the quality of comparative clinical and especially radiological measurements of tumour targets. Medical imaging plays an essential role in these assessments. The absence of standardized techniques, poor selection of targets and inaccurate measurements can bias the results, particularly those of therapeutic trials. In view of the economic, scientific and patient-related stakes involved, a very rigorous approach is essential, directly implicating the responsibility of radiologists performing assessment examinations. The World Health Organization (WHO) guidelines defining the method of measurement of solid tumours and response criteria are no longer adapted to technical progress in imaging. Recently these guidelines have been updated and a new set of criteria has been proposed by the Response Evaluation Criteria in Solid Tumors (RECIST) Group, taking into account progress in imaging. They remain based on measurement of the size of the target lesion. The use of this single criterion of size to evaluate response to treatment needs to be discussed in the light of new technologies able to provide information on tumour composition, metabolism or neovascularization, modifications of which reflect response to treatment before a reduction in tumour volume can be detected.

We report the intramedullary growth of a malignant peripheral nerve sheath tumour (MPNST). A 50year-old man developed a severe tetraparesis over a 4-month period. Following irradiation of a chronic tonsillitis during his childhood, the patient had later experienced a number of post-radiation diseases, including a laryngeal cancer that required permanent tracheotomy. Before admission, a magnetic resonance imaging (MRI) study had disclosed a C4-C5 intramedullary lesion. On admission to our Department, the patient had a nearly complete tetraparesis. At surgery, the lesion was exposed through a posterior midline myelotomy. A friable neoplasm, with no clear plane of cleavage, was found. The tumour was subtotally resected. Histological examination, which intraoperatively had not yielded a specific diagnosis, eventually revealed a MPNST, grade intermediate, with ultrastructural and immunohistochemical features consistent with a schwannian differentiation. No postoperative radiotherapy was undertaken. The patient died 9 months later from pneumonial complications. MPNSTs may develop within the spinal cord similarly to their benign schwannian counterpart. The reported sequence of events might support a possible relation between irradiation of the spinal cord and induction, followed by malignant transformation, of intramedullary schwannosis. This unique case must be added to the growing list of radiation-induced spinal cord tumours.

Outdoor air pollution and the indoor environment have been shown to cause or exacerbate childhood asthma. Allies Against Asthma coalitions implemented a broad range of activities to reduce or remediate indoor exposure to asthma environmental triggers for children with asthma including education and trigger remediation, physician and other health care provider education, and policy efforts to improve air quality in homes and schools. Outdoor environmental triggers were addressed through programs to increase education and awareness and efforts to change policies related to environmental conditions. Implementation of such efforts was complicated by the lack of safe and affordable housing and the amount of time and resources necessary to address policy change. Keys to success included promoting coordination and partnerships among coalition members, implementation of consistent messages, and building a broad and unified voice for policy change.

Breast cancer in men is an uncommon disease. Because of its rarity little is known about its aetiology, clinical behaviour and treatment. Retrospective studies show that when age- and stage-matched breast cancer in men and women are compared, there is no difference in survival between the two groups. Nevertheless, because of the absence of screening protocols and the limited amount of mammary tissue in men, allowing rapid local infiltration, a late diagnosis is often made, with a poor survival rate. Most of our current knowledge about the biology, natural history, surgical therapeutic strategies, adjuvant radiotherapy and chemotherapy protocols of male breast carcinoma has been extrapolated from its female counterpart. The Authors report the case of a male patient with breast cancer and pagetoid diffusion in the nipple region, and, on the basis of a review of the literature, summarise what is currently known about this rare neoplasm in terms of prognostic factors, therapy and survival.

Radiation therapy is an uncommon cause of stenosis and occlusions of the cervical internal carotid artery (ICA). We describe two cases of cerebral ischemia due to ICA stenosis in patients irradiated for malignant tumors (lymphoma and breast cancer). The first patient, a 32-year-old man, presented with an episode of cerebral ischemia. Six years previously he had received irradiation therapy for a left laterocervical mass histologically diagnosed at biopsy as a Hodgkin's lymphoma. Cerebral angiography on entry revealed bilateral occlusion of the cervical ICA, with a 2-cm stump at the origin of the left ICA. Despite anti-platelet aggregation therapy the ischemic attacks persisted, necessitating a stumpectomy. After vascular-repair surgery the patient had no further ischemic symptoms. The second patient, a 42-year-old woman, began to experience the sudden onset of pain in the right arm and left hemiparesis five years after surgery plus irradiation (4500 rad) for breast cancer, and three years after excision of a single cerebral metastasis. Cerebral angiography obtained on admission showed occlusion of the right ICA and right subclavian arteries, both lesions necessitating thrombectomy. After surgery the right radial pulse immediately re-appeared and the hemiparesis regressed. In both patients, 2-year follow-up assessment by Doppler ultrasonography and magnetic resonance angiography (MRA) confirmed that the operated arteries remained patent. These two unusual cases underline the potential risk of irradiation-induced ischemic cerebrovascular symptoms, suggesting that patients who have received radiation therapy to the neck and mediastinum who survive for more than 5 years should undergo regular non-invasive imaging of neck vessels (Doppler ultrasonography and MRA).

Objective: To determine the accuracy of comparative cytologic and frozen section intraoperative diagnosis in neuropathology and the relevance of diagnostic accuracy during both craniotomic and stereotactic biopsies and to provide further data on rare and/or diagnostically controversial lesions., Study Design: Both cytologic and frozen section preparations were employed in the intraoperative diagnosis of 85 consecutive central and peripheral nervous system lesions obtained from classical surgery (70 samples, 4 of which were intramedullary) and stereotactic biopsies (15 samples)., Results: Combining cytologic and frozen section details allowed a fair diagnosis in 81 cases (95.29%), confirmed on paraffin sections. In the remaining cases intraoperative misdiagnosis was due to technical-staining defects (1 case); absence of tumor differentiation, resolved only by ultrastructural examination (2 cases); and marked tumor heterogeneity, resolved by wide tissue sampling and immunohistochemistry (1 case)., Conclusion: Besides providing a general description of cytologic and frozen section criteria useful in intraoperative diagnostic neuropathology and adding further details about some problematic and/or rare entities, our work confirmed: (1) the usefulness of comparative cytologic and frozen section examination in the intraoperative diagnosis of central nervous system lesions, (2) the relevance of the accuracy of intraoperative diagnosis during both craniotomy and stereotaxis, including intramedullary samples; and (3) the importance of fair "conduct" in intraoperative neuropathology, always comparatively considering morphologic and clinicoradiologic data.

Glioblastoma multiforme is the most malignant tumor of the glial series. The average survival of patients with this tumor ranges from 6 to 12 months. The case of a patient who survived for more than 11 years after diagnosis of a temporal-occipital glioblastoma which was treated with surgery, radiotherapy and chemotherapy is described. The authors deduce that among patients with glioblastoma multiforme (GM), those with a long disease-free interval after initial diagnosis who undergo multimodal therapy, including aggressive tumor removal, are the most likely long-term survivors (LS). Other factors which appeared to be related to longer survival were younger age and high Karnofsky scores.

Objective: To evaluate the role of intraoperative cytology (IC) in the improvement of diagnostic accuracy obtained by frozen section (FS) alone., Study Design: Comparison of 2,250 intraoperative cytologies performed along with frozen sections, with the final diagnoses achieved on paraffin sections., Results: In 18 cases the diagnoses were deferred until the paraffin sections at the time of intraoperative consultation. The diagnostic accuracy in distinguishing benign from malignant lesions by combined intraoperative cytology and frozen section was 99.2%. The accuracy rate is significantly higher than that reported in large series based on frozen section preparations alone. Sensitivity and specificity were, respectively, 98.2% and 100%. The diagnostic accuracy of each technique alone was 94.9% for FS (sensitivity 89.9%, specificity 97.9%) and 96% for IC (sensitivity 94.9%, and specificity 96.8%). Although specific diagnoses were more frequently formulated on the bases of frozen section examination, FSs were not diagnostic in 113 case in which cytology allowed a specific diagnosis., Conclusion: Our results emphasize the increasingly important diagnostic role of intraoperative cytology as an adjunct to frozen section. The approach does have limitations.

A case of eosinophilic granuloma of the lesser wing of the sphenoid bone is reported. The patient was a 5-year-old white male, with left temporal-frontal headache, left III cranial nerve palsy, left exophthalmos and ptosis caused by an osteolytic lesion of the anterior clinoid process extending to the left optic canal and cavernous sinus. The patient underwent surgical resection of pathologic tissue. Pathologic diagnosis was eosinophilic granuloma of the sphenoid bone. Surgical management, postoperative prognosis and differential diagnosis of eosinophilic granuloma of the skull base are discussed along with a review of the literature.

Seventy-five breast samples including normal tissue, hyperplastic, metaplastic, atypical and neoplastic lesions were employed for the determination of interphasic Nucleolar Organizer Regions (NORs) modifications and Proliferating Cell Nuclear Antigen (PCNA) immunoreactivity. Interphase NORs were quantitatively and qualitatively modified in atypical lesions and breast carcinomas, whereas only modifications in the Ag-NORs count were found in benign samples. Our results investigated the nature of interphase NORs in the hope of finding a use for their evaluation in the diagnosis and biological clarification of breast epithelial atypia.

Single-photon emission tomography (SPET) with thallium-201 is used in the assessment of patients with gliomas because the amount of 201Tl accumulated by the tumoral cells increases in proportion to the degree of tumour malignancy, thus making it possible to differentiate high-grade from low-grade gliomas or recurrences from radiation necrosis. However, in large areas of tissue such as those examined in 201Tl SPET studies, the uptake of 201Tl may vary considerably even in tumours with the same histological diagnosis, as occurs in glioblastomas (GBMs). In order to evaluate the possible influence of the macroscopic characteristics of tumours on 201Tl uptake, we studied a series of 13 patients with histologically proven GBMs, comparing magnetic resonance imaging (MRI) parameters such as tumour dimensions, perilesional oedema, intratumoral necrosis and contrast enhancement with the degree of 201Tl uptake. The patients underwent both 201Tl SPET and MRI before surgery. The 201Tl index (tumour/contralateral unaffected brain) was calculated using two different region of interest (ROI) methods: the first employed irregular large ROIs (3.2+/-13.9 cm2) including pixels with more than 50% maximum activity; the second employed regular square small ROIs (2.7 cm2) centered on the maximum activity of the lesion. Of the MRI morphological parameters studied, only necrosis significantly reduced the degree of 201Tl uptake in GBMs when larger ROIs were used. However, by using small regular ROIs the influence of necrosis on 201Tl uptake was found to be less relevant. Since necrosis is related to tumour proliferative activity and represents a negative prognostic factor in astrocytoma, a possible underestimation of 201Tl uptake due to intratumoral necrosis must be carefully evaluated.

An endoscopic screening was carried out during the period between July 1989 and December 1991 in the Municipality of Roccagorga (LT) in order to: a) evaluate the presence of various forms of gastritis and pre-cancerous lesions; 2) verify the effect of the administration of prostaglandins (Misoprostol) on the evolution of superficial chronic gastritis (CG). A total of 468 endoscopy were performed (17% of the population aged between 20 and 75 years old). 22% of the subjects examined were found to be endoscopically normal; 34% presented symptoms of mild esophagitis and 4% of moderate esophagitis. The prevalence of duodenal ulcer was 10.6% and gastric ulcer 3.4%. Gastric carcinoma was diagnosed in 6 patients (1.2%). 8.5% of patients were found to have atrophic CG and 15.3% superficial CG. Thirty-six patients with superficial CG were randomly divided into two groups: A) treated with Misoprostol 600 mg/day for 6 months; B) controls (placebo). The administration of Misoprostol did not influence the evolution of CG, whereas it caused a reduction in the incidence of type 1 intestinal metaplasia. Misoprostol also led to an improvement in dyspeptic symptoms. The results of the present study do not suggest a role of prostaglandins in the natural evolution of CG.

A model for the solution structure of horse heart ferrocytochrome c has been determined by nuclear magnetic resonance spectroscopy combined with hybrid distance geometry-simulated annealing calculations. Forty-four highly refined structures were obtained using a total of 1940 distance constraints based on the observed magnitude of nuclear Overhauser effects and 85 torsional angle restraints based on the magnitude of determined J-coupling constants. The all-residue root mean square deviation about the average structure is 0.47 +/- 0.09 A for the backbone N, C alpha, and C' atoms and 0.91 +/- 0.07 A for all heavy atoms. The overall topology of the model for solution structure is very similar to that seen in previously reported models for crystal structures of homologous c-type cytochromes. However, a detailed comparison between the model for the solution structure and the available model for the crystal structure of tuna ferrocytochrome c indicates significant differences in a number of secondary and tertiary structural features. For example, two of the three main helices display 3(10) to alpha-helical transitions resulting in bifurcation of main-chain hydrogen bond acceptor carbonyls. The N- and C-terminal helices are tightly packed and display several interhelical interactions not seen in previously reported models. The geometry of heme ligation is well-defined and completely consistent with the crystal structures of homologous cytochromes c as are the locations of four of six structural water molecules. Though the total solvent-accessible surface area of the protoporphyrin ring is similar to that seen in crystal studies of tuna ferrocytochrome c, the distribution is somewhat different. This is mainly due to a difference in packing of residues Phe-82 and Ile-81 such that Ile-81 crosses the edge of the heme in the solution structure. These and other observations help to explain a range of physical and biological data spanning the redox properties, folding, molecular recognition, and stability of the protein.

Twenty-three patients with cirrhosis (alcoholic, post-hepatitic and cryptogenetic), who underwent hepatic venous catheterization and hepatic biopsy, were included in a histopathologic study to identify morphologic features correlated with the values of corrected sinusoidal pressure. The alterations in acinar architecture were investigated by histomorphometry and could be described as: a) multiacinar fibrosis with partial persistence of normal afferent and efferent vascular structures; b) complex acinar fibrosis with partial persistence of afferent structures alone; and c) simple acinar and subacinar fibrosis with almost complete disappearance of normal vascular structures. A significant negative correlation (p < 0.05) was found between corrected sinusoidal pressure values and the percentage of portal spaces not involved in the process of bridging fibrosis, indicated as "residual portal spaces". Residual portal space evaluation can therefore be suggested as an easily quantifiable morphologic feature indicative of portal pressure.

Two cases of multicystic peritoneal mesothelioma (MPM) are reported. Ultrastructural and immunohistochemical techniques confirmed the mesothelial nature of the lesion. The biologic and clinical behaviour, pathogenesis and differential diagnoses of this rare pathology are discussed. Although regarded as a neoplasm, many analogies seem to link MPM to fibromatoses and other non-neoplastic lesions, suggesting a reactive hyperplastic process. The relationships between mesothelium and the secondary Müllerian system, to date not fully investigated, are stressed and a classification of the coelomatic reactive and neoplastic processes, both metaplastic (müllerian metaplasia) and non-metaplastic, is suggested.

The authors present 4 cases of Krukenberg tumour of the ovary, secondary to carcinoma of the stomach (3 cases) and carcinoma of the breast (1 case). Pathologically it is characterized by the presence of typical signet ring cells and a diffuse infiltration of the stroma that gives the appearance of a sarcoma. Clinical data, computed tomography (CT) and sonographic findings in these four cases are analyzed. A review of the literature concerning this condition is provided and the treatment of the disease is discussed emphasizing the role of prophylactic oophorectomy.

The authors review 274 cases of Merkel's cells tumor reported in literature and present one case they personally observed. This kind of neoplasm develops itself inside the derma without involving the epidermidis and shows an aggressive biological behaviour. The authors describe its anatomopathologic characteristics and underline the importance of the immunohistochemistry particularly for a differential diagnosis with respect to lymphoma, amelanotic melanoma and the scarcely differentiated metastatic carcinoma. Undoubtedly the surgical treatment is to be preferred. It consists of the removal of the primitive lesion together with a preventive regional lymphadenectomy. Radio and chemotherapy still don't play a standard role, their results are anyway encouraging even if not well defined up to now. These therapies are used in several ways: together with surgery in case of local relapses or metastasis or as sole treatment. In consideration of the small number of available data, we can finally state that Merkel's cells tumor must be further studied in order to come to a certain definition of this neoplasm from a histogenetic and anatomopathologic point of view and, above all, to find out a treatment able to reduce the high mortality rate that still today characterizes the prognosis.

The results of extracorporeal shock wave lithotrity (Dornier lithotriptor) for 700 cases of urinary calculi have been reviewed and correlated with the radiological features of the calculi in order to define some predictive radiological criteria of effectiveness. The calculi were broken up in 74.5% of all cases, complete destruction (no residual fragment) was achieved in 34.5% and partial destruction in 40% of cases. The rate of failure (failure to break up or scatter the calculus) is 8.9%. Complications were observed in 2.6% of all cases, a second session of lithotrity or a surgical operation was required in 4.8% of cases (evolution lost to follow-up: 9.2%). The comparison of these results with the radiological data obtained before lithotrity allows distinguishing 2 categories of calculi: 1) Calculi with a favorable prognosis: single, smaller than 1 cm, pyelic, not very opaque and heterogeneous, located in normal-sized cavities; 2) calculi with a poor prognosis: multiple, larger than 2 cm, lower calyceal or ureteral, very opaque and homogeneous, located within dilated cavities.

A case of primary dissection of the celiac trunk in a young hypertensive patient is presented. The diagnosis, suspected by ultrasonography, was confirmed by angiography and CT which also allowed a study of the visceral complications. Appropriate surgical treatment was successfully carried out.

Venous tumor invasion in 42 renal cell carcinomas was evaluated by MRI. A correct diagnosis of renal vein and inferior vena cava (IVC) involvement was made in 14 of 17 tumors: 1 false negative diagnosis of right renal vein invasion was due to a double renal vein in which the inferior vein (identified by MRI) was not involved; 2 cases of IVC involvement were understaged (1 case of suprahepatic extension) or not identified (the false negative of renal vein invasion previously described). One false positive (among 31 tumors without venous invasion) was reported in a case of a large tumor in which the compressed but free right renal vein was overevaluated by MRI.

A never previously reported association between mediastinal angiofollicular lymph node hyperplasia (ALNH) of the hyaline vascular type and mucocutaneous manifestations in a twenty-one-year-old man is described. Mucocutaneous lesions, unresponsive to medical therapy, promptly disappeared after resection of the mediastinal mass, indicating, as suggested for the plasmacell type, a close relationship between the systemic manifestations and ALNH.

Based on a personal series of 47 cases of aberrant papillae and a review of the literature, the authors stress the relative frequency of this anomaly and the almost constant possibility of making the diagnosis by means of intravenous pyelography on the basis of the following signs: regular, round or oval filling defect, surrounded by a fine opaque halo which separates it from the surrounding urine; or a notch with a regular arc-shaped border prolonged towards the exterior at its two extremities by a small spur. This spur, like the halo on the frontal view, corresponds to the presence of a small fornix at the insertion of the wall into the papilla. In doubtful cases, the persistence and stability of the image on repeated films constitutes a valuable diagnostic element. Haematuria is not more frequent in cases of aberrant papillae than in the overall population seen in a urological radiology department; in most cases, it is unrelated to this papilla. Only exceptional cases presenting with bleeding from the papilla may raise diagnostic problems due to the irregular contours of this papilla as a result of the vascular dysplasia responsible or the presence of clots. However, the finding of an opaque halo at the periphery of the filling defect or a spur at the extremities of the notch should draw attention, suggest the diagnosis and prohibit any aggressive management.

The 1H resonances of human ubiquitin were studied by two-dimensional nuclear magnetic resonance techniques. A recently introduced assignment algorithm termed the main chain directed (MCD) assignment [Englander, S. W., & Wand, A. J. (1987) Biochemistry 26, 5953-5958] was applied. This approach relies on an ordered series of searches for prescribed patterns of connectivities in two-dimensional J-correlated and nuclear Overhauser effect spectra and centers on the dipolar interactions involving main-chain amide NH, alpha-CH, and beta-CH. Unlike the sequential assignment procedure, the MCD approach does not rest upon definition of side-chain J-coupled networks and is generally not sequential with the primary sequence of the protein. The various MCD patterns and the general algorithm are reiterated and applied to the analysis of human ubiquitin. With this algorithm, the vast majority of amino acid residue amide NH-C alpha H-C beta H J-coupled subspin systems could be associated with and aligned within units of secondary structure without any knowledge of the identity of the side chains. This greatly simplified recognition of side-chain spin systems by restricting their identity. Essentially complete resonance assignments are presented. The MCD method is compared with the sequential assignment method in some detail. The MCD method is highly amenable to automation. Human ubiquitin is found, at pH 5.8 and 30 degrees C, to be composed of an extensive beta-sheet structure involving five strands. Three of these strands form an antiparallel set sharing a common strand and have a parallel orientation to two antiparallel strands. Two helical segments were also observed. The largest, spanning 13 residues, shows dipolar interactions consistent with an alpha-helix while the smaller 4-residue helical segment appears, on the basis of observed nuclear Overhauser effects, to be a 3(10) helix. Five classical tight turns could be demonstrated.

Two-dimensional nuclear magnetic resonance spectroscopy (2D NMR) was used to obtain extensive resonance assignments in the 1H NMR spectrum of horse ferricytochrome c. Assignments were made for the main-chain and C beta protons of 102 residues (all except Pro-44 and Gly-84) and the majority of side-chain protons. As starting points for the assignment of the oxidized protein, a limited set of protons was initially assigned by use of 2D NMR magnetization transfer methods to correlate resonances in the oxidized form with assigned resonances in the reduced form [Wand, A. J., Di Stefano, D. L., Feng, Y., Roder, H., & Englander, S. W. (1989) Biochemistry (preceding paper in this issue)]. Given the complexity of the spectrum due to the size of this protein (104 residues) and its paramagnetic center, the initial search for side-chain spin systems in J-correlated spectra was successful only for the simplest side chains, but the majority of NH-C alpha H-C beta H subspin systems (NAB sets) could be identified at this stage. The subsequent search for sequential NOE connectivities focused on NAB sets, with use of previously assigned residues to place NOE-connected segments within the amino acid sequence. Selective proton labeling of either the slowly or the rapidly exchanging amide sites was used to simplify the spectra, and systematic work at two temperatures was used to resolve ambiguities in the 2D NMR spectra. These approaches, together with the use of magnetization transfer methods to correlate reduced and oxidized cytochrome c spectra, provide multiple cross-checks to verify assignments.

Reduced (GSH), oxidized (GSSG), and protein-bound (PSSG) glutathione were determined in dry and hydrated wheat embryos. Dry embryos contained about 0.6 mumoles per gram dry weight each of GSSG and PSSG, and these levels declined 5- to 10-fold within minutes after the onset of imbibition. GSH declined from about 8 to 2 mumoles per gram over a period of 90 minutes. Similar changes occurred when embryos were hydrated by storage at 100% relative humidity. The decline in glutathione levels was not reversed upon redrying hydrated embryos. About 40% of the cysteine residues of embryo protein was found to be in the disulfide form in both dry and imbibed embryos. The ability of wheat embryos to withstand heat shock was shown to correlate with water content but not GSSG content. Incorporation of [(35)S]methionine into protein was studied using a system based upon wheat embryo extract (S23). Incorporation rate was found to be sensitive to the nature of thiol added to the system and to be decreased by GSSG. S23 exhibited a substantial capacity to reduce GSSG and preparation of S23 having a GSSG content comparable to dry embryos required addition of large amounts of GSSG to the extraction buffer S23 prepared in this fashion exhibited a marked decrease in ability to support protein synthesis. These results suggest that the early decrease in GSSG during germination is necessary for optimal protein synthesis in wheat embryo.

Two-dimensional nuclear magnetic resonance (NMR) spectroscopy was used to assign the proton resonances of horse ferrocytochrome c. Assignments were based on the main chain directed (MCD) and sequential assignment procedures. The fundamental units of the MCD approach, the main-chain NH-C alpha H-C beta H J-coupled subspin systems of each amino acid residue (NAB sets), were defined by analysis of direct and relayed coherence transfer spectra. Recognition of main-chain NOE connectivity patterns specified in the MCD algorithm then allowed NAB sets to be aligned in their proper juxtaposition within secondary structural units. The units of secondary structure were placed within the polypeptide sequence of identification of a small number of side-chain J-coupled spin systems, found by direct recognition in 2D spectra of some J-coupled spin systems and by pairwise comparisons of the J-correlated spectra of six homologous cytochromes c having a small number of known amino acid differences. The placement of a given segment in this way defines the amino acid identity of all its NAB sets. This foreknowledge allowed the vast majority of the side-chain resonances to be discerned in J-correlated spectra. Extensive confirmation of the assignments derives internally from multiple main-chain NOE connectivities and their consistency following temperature-induced changes of the chemical shifts of NOE-correlated protons. The observed patterns of main-chain NOEs provide some structural information and suggest small but potentially significant differences between the solution structure observed by NMR and that defined earlier in crystallographic studies at 2.8-A resolution.

The Authors describe an experimental model that makes feasible to endoscopically approach a Roux-en Y hepatico-jejunostomy through a percutaneous transjejunal route. Potentials for its clinical application are briefly discussed.