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Arylamine-DNA adducts formation in tissues has been correlated with the carcinogenic effect of heterocyclic aromatic amines. Carmustine (BCNU) is a commercially available nitrosourea derivative and chloroethyl nitrosourea compound which is applied in anti-neoplastic therapy especially in central nervous system. The effects of carmustine on Aminofluorene-DNA (AF-DNA) formation in rat glioma cells were investigated by gamma-[32p]-dATP and high performance liquid chromatography (HPLC) using 2-aminofluorene (AF) as substrate. In the presence of 8 microM carmustine, the AF-DNA adduct formation was decreased 10.6% and 15.6% in 30 microM and 60 microM of AF (p0.05), respectively; In the presence of 80 microM carmustine the AF-DNA adduct formation was decreased 39.6% and 40% in 30 microM and 60 microM of AF (p0.02), respectively. These results show that BCNU could decrease AF-DNA formation in rat glial tumor cells.

During the outbreak of Nipah virus encephalitis in Malaysia, stored cerebrospinal fluid (CSF) samples from 84 patients (27 fatal and 57 nonfatal cases) were cultured for the virus. The virus was isolated from 17 fatal cases and 1 nonfatal case. There were significant associations between CSF virus isolation and mortality as well as clinical features associated with poor prognosis. In addition, there was a positive linear correlation of CSF virus isolation with age. There was no significant association between CSF virus isolation and the character of the CSF, presence of Nipah-specific antibody in the serum or CSF, duration of illness before collection of samples, or sex or ethnicity of the patients. This study suggests that high viral replication in the central nervous system may be an important factor for high mortality.

Two major epidemics of viral encephalitis occurred in Asia in 1997 and 1998. The first was a re-emergence of neurovirulent strains of enterovirus 71, which caused severe encephalomyelitis in children in Malaysia, Taiwan and Japan, on a background of hand, foot and mouth disease. Necropsy studies of patients who died of enterovirus 71 infection showed severe perivascular cuffing, parenchymal inflammation and neuronophagia in the spinal cord, brainstem and diencephalon, and in focal areas in the cerebellum and cerebrum. Although no viral inclusions were detected, immunohistochemistry showed viral antigen in the neuronal cytoplasm. Inflammation was often more extensive than neuronal infection, suggesting that other factors, in addition to direct viral cytolysis, may be involved in tissue damage. The second epidemic of viral encephalitis was the result of a novel paramyxovirus called Nipah, which mainly involved pig handlers in Malaysia and Singapore. Pathological evidence suggested that the endothelium of small blood vessels in the central nervous system was particularly susceptible to infection. This led to disseminated endothelial damage and syncytium formation, vasculitis, thrombosis, ischaemia and microinfarction. However, there was also evidence of neuronal infection by the virus and this may also have contributed to the neurological dysfunction in Nipah encephalitis. Some patients who seemed to recover from the acute symptoms have been re-admitted with clinical findings suggestive of relapsing encephalitis. As these two epidemics indicate, the emergence and re-emergence of viral encephalitides continue to pose considerable challenges to the neuropathologist, in establishing the diagnosis and unravelling the pathogenesis of the neurological disease.

Arylamine N-acetylation capacity by the N-acetyltransferase (NAT) may be an important causative factor in the initiation of cancer. Arylamine-DNA adducts formation have been correlated with the carcinogenic effect of heterocyclic aromatic amines. NAT activity in rat glial tumor cells was measured by high performance liquid chromatography (HPLC) using 2-aminofluorene (2-AF) and p-aminobenzoic acid (PABA) as substrares. 2-AF-DNA adducts formation in rat glial tumor cells was investigated by gamma-[32p]-dATP and HPLC using 2-aminofluorene as substrates. The activities (Mean +/- SD) of NAT in rat glial cells was 1.08 +/- 0.18 nmol/min/mg protein for the acetylation of 2-aminofluorene (n = 12), and 0.96 +/- 0.16 nmol/min/mg protein for the acetylation of p-aminobenzoic acid (n = 12). 2-AF-DNA adducts formation in rat glial tumor cells with 30 microM and 60 microM AF were 0.48 +/- 0.16 and 0.70 +/- 0.12 pmol/mg DNA, respectively. The results indicate that NAT was present in rat glial tumor cells, activating AF to become a metabolite able to bind covalently with DNA to form 2-AF-DNA.

To the Editor: The recent melamine contamination of infant formula and milk products in China placed thousands of children in China and neighboring regions at risk for renal-stone formation and renal failure; six deaths were reported. In the wake of the crisis, screening programs were launched nationwide in the mainland of China. A similar program was initiated in Hong Kong1; here, we describe the results. From September 28 through October 17, 2008, a total of 2140 children (1177 boys and 963 girls; age range, 1 month to 12 years; mean age, 6.45 years), all asymptomatic, underwent ultrasonographic screening at . . .

A 28-year-old lady suffering from systemic lupus erythomatosus (SLE) with diffuse proliferative glomerulonephritis (DPGN) and who was on oral cyclophosphamide and prednisolone presented with left lower limb 'cellulitis'. The 'cellulitis' of the left lower limb failed to respond to usual antibiotics which prompted evaluation of the clinical diagnosis. The diagnosis is made based on the presence of granulomas, multinucleated giant cells and acid fast bacilli on the skin biopsy.

A case of desmoplastic small round cell tumour (DSRCT) is presented. This aggressive and rare neoplasm predominantly affects males and is almost exclusively intraabdominal in location. It is unique in that neural, mesenchymal and epithelial markers are co-expressed. Despite multi-modal therapy, the prognosis is extremely poor. The present report details the clinical features and typical pathological findings of DSRCT in an 11-year-old boy, who succumbed to the disease 16 months after diagnosis despite multiple chemotherapeutic regimes.

A 24-year-old man who was initially thought to have nocardiosis of his mediastinal lymph node which progressed to involve his right lung, had to undergo a right pneumonectomy when he failed to respond to treatment with sulphadiazine. Histology of the right lung specimen and a subsequent axillary lymph node biopsy revealed that he actually had lymphocyte-depleted Hodgkin's disease.

A rare case of a 22-week-old foetus with unilateral adrenal cytomegaly and left diaphragmatic hernia is reported. Typical cytomegalic cells were found focally in the left adrenal but the right adrenal was normal. There was no stigmata of the Beckwith-Wiedermann syndrome. The association of adrenal cytomegaly with various congenital malformations, the significance and possible pathogenesis of this condition is discussed.

In vitro infection of insect cells with baculoviruses is increasingly considered a viable means for the production of biopesticides, recombinant veterinary vaccines, and other recombinant products. Batch fermentation processes traditionally employ intermediate to high multiplicities of infection necessitating two parallel scale-up processes-one for cells and one for virus. In this study, we consider the use of multiplicities of infection as low as 0.0001 plaque-forming units per cell, a virus level low enough to enable infection of even large reactors (e.g., 10 m(3)) directly from a frozen stock. Using low multiplicities in the Sf9/beta-gal-AcNPV system, recombinant protein titers comparable with the maximum titer observed in high multiplicity infections were achieved. Cultures yielding the maximum titer were characterized by reaching a maximum cell density between 3 and 4 x 10(9) cell L(-1). This optimal cell yield did not depend on the multiplicity of infection, supporting the existing view that batch cultures are limited by availability of substrate. Up to a certain cell density, product titer will increase almost linearly with availability of biocatalyst, that is, cells. Beyond this point any further cell formation comes at the expense of final product titer. Low multiplicity infections were found not to cause any significant dispersion of the protein production process. Hence, product stability is not a major issue of concern using low multiplicities of infection. The sensitivity to initial conditions and disturbances, however, remains an issue of concern for the commercial use of low multiplicity infections. (c) 1996 John WileySons, Inc.

Neurofibrillary tangle (NFT) formation is a feature of postencephalitic Parkinsonism (PEP) and Alzheimer's disease (AD). Tangle formation has been compared immunohistochemically in these 2 conditions. Staining patterns for tau protein, ubiquitin and beta/A4 amyloid protein were studied in frontal lobe, hippocampus, and midbrain in 2 classical cases of PEP, 2 cases of AD and 2 controls matched for age and sex. NFTs were present in all cases, but with varying frequency: all tangles were tau-positive and many were ubiquitinated. In the frontal cortex and hippocampus, irrespective of the case category, tangle formation was associated with beta/A4 amyloid deposition. A similar association was present in the 2 AD cases in the midbrain. However, in PEP tangle formation in the midbrain was not associated with adjacent beta/A4 amyloid deposition. This finding raises the possibility that the pathogenetic mechanism of tangle formation in PEP is different from that of AD, although the final cellular morphological expression of abnormality in both conditions is similar.

We report a patient who suffered from severe acute respiratory distress syndrome (SARS) presented with an uncommon chest X-ray finding, lobar pneumonia, which was never reported. We hope that this case report can help clinicians to become more aware of various initial radiological findings of SARS.

An asymptomatic middle-aged women was investigated for a lung nodule detected on routine chest X-ray. Percutaneous needle biopsy revealed it to be a sclerosing haemangioma which was subsequently removed by a left lower lobectomy. The literature on this uncommon benign lesion is reviewed.

PURPOSE: To characterize with magnetization transfer imaging the pathologic substrate of the nonspecific periventricular hyperintense white matter changes seen on T2-weighted images of elderly patients. METHODS: Twenty-one elderly patients with periventricular hyperintense white matter on T2-weighted MR images and eleven control subjects were studied using MT technique. Magnetization transfer ratios (MTRs) were calculated for the periventricular hyperintense white matter and normal-appearing white matter. These MTRs were correlated with histopathologic changes that have previously been reported as well as with established MTRs for other lesions. RESULTS: The MTRs (mean, 35.2; SD, 1.2) in the periventricular hyperintense white matter are lower than those in the normal white matter of the patient (mean, 40.8; SD, 1.4) and control (mean, 41.3; SD, 1.8) groups. These MTRs are much higher than those of demyelinating lesions but are similar to those of experimental lesions with just edema. CONCLUSION: Because MTR may reflect to some extent histopathologic changes and thus provide more specificity than conventional pulse sequences, the main pathologic substrate accounting for the lower MTR in periventricular hyperintense white matter is probably the increased water content in reactive astrocytes.

The purpose of this study was to determine whether the CT attenuation value of the lens is helpful in diagnosing acute traumatic cataracts in patients with complicated eye injuries that preclude evaluation by any other means.The CT attenuation values of the lenses of 69 patients with acute orbital trauma, including 24 patients with clinically and surgically diagnosed acute traumatic cataracts, were compared with attenuation values of their own contralateral lens and with the attenuation values of the lenses of 103 consecutive asymptomatic control subjects. The study group was composed of consecutive patients with unilateral orbital trauma who were clinically evaluated and referred for CT examination within 48 hr after their initial injury. In all patients, attenuation measurements of the injured lenses were obtained and compared with those of the contralateral lens as an internal control. All surgically diagnosed cataracts were histologically confirmed.The CT attenuation measurement of a lens in any asymptomatic control subject was identical (within the range of the standard deviation) to the measurement of the contralateral lens of that control patient. In patients with orbital injury, the CT attenuation of the patient's cataractous lens was markedly lower than in the contralateral lens (mean density difference, 30 H, p.0001). This decreased attenuation corresponds to acute cataract formation with increased fluid within the lens. No patient with normal attenuation values of the lens in the traumatized globe (as compared with the contralateral lens) was found to have an acute traumatic cataract or have a cataract develop within a 1-year follow-up period.CT may be useful in the examination of patients with acute traumatic cataracts, unsuspected lens injury, opacification of the anterior chamber, or other injuries of the globe with complications that preclude lens evaluation by any other means. This prompt diagnosis may allow timely removal of the lens in appropriate clinical circumstances, preventing damage to the anterior chamber of the globe and other complications of delayed diagnosis and treatment. Further, normal CT findings at the time of trauma suggest that the lens will not undergo acute traumatic cataract formation.

The ultrastructure of the human skeletal muscle sarcocyst found in Malaysia is reported. Sarcocyst-positive, formalin-fixed tongue tissues were postfixed in osmium tetroxide. The primary cyst wall consisted of a thin membrane supported by osmiophilic material that was interrupted regularly by vesicle-like invaginations. Although there were no cytophaneres, stubby protrusions of the primary wall were observed. These protrusions were accentuated by dense, curvilinear material externally. The primary wall was wavy over about half the cross section of the cyst. The granular ground substance underlying the primary wall occasionally contained hitherto undescribed coiled microtubular structures. Branching septa extended from the ground substance into the cyst, separating mature merozoites into compartments. A few peripheral metrocytes and many laminated myelin figure-like structures, probably degenerating merozoites, were found. Although the human muscular sarcocyst has the same basic ultrastructure as those found in other animals, the stubby protrusions and coiled microtubular structures in the ground substance have not been described previously in nonhuman animals.

Aim : To determine the risk factors for developing phacomorphic glaucoma in eyes with mature cataracts. Materials and Methods : This is a case-control study comprising of 90 eyes with phacomorphic glaucoma and 90 age- and sex-matched control eyes with mature cataracts without phacomorphic glaucoma. Patients with pre-existing glaucoma, previous intraocular surgery and /or absence of documented axial lengths were excluded from this study. Binary logistic regression analysis of the variables, axial length and anterior chamber depth, was performed. Anterior chamber depth of the contralateral eye was used as a proxy measure of the pre-phacomorphic state in the eye with phacomorphic glaucoma as majority of them first presented to our center during the phacomorphic attack without prior measurements of the pre-phacomorphic ACD or lens thickness; therefore, their anterior chamber depth would not be representative of their pre-phacomorphic state. Axial length of 23.7 mm was selected as a cut-off for dichotomized logistic regression based on the local population mean from published demographic data. Results : The mean age was 73.1 ± 10.2 years. All phacomorphic and control eyes were ethnic Chinese. The mean presenting intraocular pressures were 49.5 ± 11.8 mmHg and 16.7 ± 1.7 mmHg in the phacomorphic and control eyes respectively (P< 0.0001), whilst the median Snellen best corrected visual acuity were light perception and hand movement in the phacomorphic and control eyes respectively. Eyes with phacomorphic glaucoma had shorter axial length of 23.1 ± 0.9 mm median when compared with that of control eyes, 23.7 ± 1.5 mm (P = 0.0006). Eyes with AL ≤ 23.7 mm were 4.3 times as likely to develop phacomorphic glaucoma when compared with AL > 23.7 mm (P = 0.003). Conclusion : Axial length less than ≤ 23.7 mm was a risk factor for developing phacomorphic glaucoma. Eyes with AL shorter than the population mean were 4.3 times as likely to develop phacomorphic glaucoma compared with eyes with longer than average AL. In an area where phacomorphic glaucoma is prevalent and medical resources are limited, patients with AL shorter than their population mean may be considered for earlier elective cataract extraction as a preventive measure.

We describe the case of a 48 year old Indian female with hypercalcemia due to tuberculosis. She presented with symptoms of hypercalcemia and chest radiographs showed bilateral hilar lymphadenopathy with normal lung fields. The diagnosis of tuberculosis was made histologically from biopsy of the enlarged hilar nodes. Her hypercalcemia resolved following one month of anti-tuberculous treatment. The prevalence of hypercalcemia in tuberculosis has been reported to be high in western series. There is, however, a paucity of local data on the subject. The presence of 1-alpha-hydroxylase-like activity in pulmonary alveolar macrophages with resulting increased formation of active vitamin D metabolites is the postulated mechanism of tuberculosis associated hypercalcemia.

We describe the design and management of a 35 mm slide database using a menu-driven dBASE III PLUS programme and a microcomputer in a large department of pathology that also caters for the individual pathologist. Existing systems described in the literature are geared towards slides of general medicine and do not address the needs of the individual pathologist. A total of 11,481 slides in the Department of Pathology, Faculty of Medicine, University of Malaya, were filed into a single database with each record representing one slide. Nine fields which comprised the slide accession number, reference number, slide category, SNOMED codes, and a description of the slide in natural language, seemed adequate for slide definition. The menu-driven programme had functions which included the abilities to add, delete, edit and back-up records, and to search for desired slides. Although slides may be searched for in various fields, we found that searches using natural language alone were both comprehensive and efficient, provided a standard format of description was adhered to and data entries scrutinized carefully for errors. We believe therefore, that for the pathologist working alone, coded language fields are not absolutely necessary, as manual coding and additional data entry can be time consuming. As expected, for databases larger than 10,000 slides, a 80286 microprocessor-based microcomputer was more efficient. We are of the opinion that a system such as ours is very useful for a large department of pathology or the individual pathologist to file and retrieve 35 mm slides.

A retrospective study of 37 cases of multiple myeloma admitted from 1980 to 1987 to the University Hospital Kuala Lumpur, Malaysia, was carried out to analyse the biodata, clinical presentation, laboratory and radiological profiles. The cases were selected after they had satisfied preset diagnostic criteria. The mean age was 60 years. There was no sex or ethnic preponderance. The most common symptom was bone pain. Pallor was detected in 73% of the patients. Haemoglobin was less than 120 g/L in 95%, and ESR was greater than 100 mm/hr in 70% of cases. Bone marrow and trephine biopsies were diagnostically important. Hypercalcaemia occurred in seven cases out of which three were IgA myelomas. Either serum creatinine or blood urea was raised in nearly 50% of cases. The most common heavy chain paraprotein was IgG while Kappa light chain was the commoner light chain type. 86% of cases had osteolytic lesions. These findings are, in general, similar to those of larger studies on multiple myeloma.

20003 Background: EBV DNA is detectable in the plasma in most patients (Pts) with lymphoepithelial carcinoma (LECA) and in some Pts with squamous cell carcinoma (SCC) of the HN. We investigated the prognostic significance of plasma EBV DNA level in a prospective phase II trial of concurrent cisplatin and CBRT for locally advanced HN carcinomas. Methods: Eligibility criteria included newly-diagnosed SCC or LECA of non-nasopharyngeal HN sites; stage III or IV disease; ECOG performance status ≤ 1; and age ≤ 70 years. Plasma EBV DNA levels were measured by real-time quantitative polymerase chain reaction (PCR) before treatment and at 6 weeks post-treatment. Pre-treatment gross tumor volume (GTV) was measured on CT, and invasion of bone and cartilage was assessed on CT and MRI. Cisplatin 40–50 mg/m2 was given on days 1, 8, 15 and 22 of CBRT. Radiotherapy consisted of 54 Gy/30 fractions/6 weeks and a concomitant boost (18 Gy/12 fractions) in the last 12 treatment days. The primary endpoint was overall survival (OS) and the secondary endpoint was progression-free survival (PFS). Survival curves were compared by the log-rank test and multivariate analysis was performed with Cox regression. Results: Between March 2001 and January 2005, 46 Pts were recruited (36 with SCC and 10 with LECA). Thirty-four Pts had stage III and 12 had stage IV disease. Pre-treatment plasma EBV DNA level was > 0 copy/ml in all Pts with LECA (range, 37 - 211737 copies/ml) and in 8 Pts with SCC (range, 10 - 48734 copies/ml). Ten Pts had plasma EBV DNA level > 0 copy/ml at 6 weeks post-treatment. With a median follow-up of 1.6 years, the 1-year OS rate was 87.7 % and 1-year PFS rate was 68.3%. On multivariate analysis, plasma EBV DNA > 0 copy/ml at 6 weeks post-treatment was the only independent predictive factor of decreased OS [hazard ratio (HR) 3.59, p = 0.04] for the entire group. In the subgroup of Pts with SCC, pre-treatment EBV DNA > 0 copy/ml was the only independent predictive factor of decreased locoregional PFS (HR 7.08, p = 0.03). Conclusions: Plasma EBV DNA level is a prognostic factor in Pts with locally advanced HN SCC and LECA. Further studies are warranted to confirm the finding and to elucidate its biological basis. No significant financial relationships to disclose.

One of the most difficult tasks in database design is the collection of relevant information needed for database design. This information can be separated into two categories: information about the processes which use, modify or produce the data, and information about the data which is used, modified, or produced by the processes. This paper describes a "forms" oriented requirements specification facility as a formal means for capturing the information crucial for database design. Both kinds of information are expressible by the proposed structured forms specification. Furthermore, not only the application usage, but also the integrity constraints that must be maintained in the database can be captured in a concise, unambiguous and machine manipulable manner. The concepts underlying the forms approach are few and simple, hence it is easy to use for the database designer and can be understood by non-computer specialists. This facilitates the cooperation from users to participate in the specification of database application requirements.

Three cores, one kilometer apart, from each of seven locations along Lake Erie were analyzed for heavy metals and dated by 210 Pb techniques. The sedimentary record of anthropogenic inputs of heavy metals parallels the increasing intensity of cultural activity in the lake basin. On the average, pollution sources annually contribute 0.4 μg of Cd, 12 μg of Cu, 12 μg of Pb and 36 μg of Zn deposited per each cm 2 of the Eastern Basin sediments: 0.5, 8.8, 11 and 31 μg of Cd, Cu, Pb and Zn, respectively, deposited per cm 2 of Western Basin sediments and 0.7, 1.4, 2.0 and 5.6 μg of Cd, Cu, Pb and Zn, respectively, deposited per cm 2 of fine-grained sediments in the Central Basin. These anthropogenic flux rates exceed the pre-colonial data by 80–600%. The mean flux rates for 210 Pb into the Eastern. Central and Western Basins are 0.45, 0.07 and 0.15dpm cm −2 yr −1 . respectively. From an inventory of sources and sinks of the metals, it is shown that about 2500 × 10 3 kg of Cu. 1900 × 10 3 kg of Pb and 6750 × 10 3 kg of Zn are delivered annually into the lake. The calculated retention in the lake sediments of 45%, 65% and 35% of the total annual inputs of Cu. Pb and Zn, respectively, agrees closely with the accumulation of data derived from sediment analyses. Sewage discharges, direct and indirect, are shown to be an important source of metal in the lake. The mean residence times in the water column are inferred to be 104 days for Cu. 180 days for Pb and 152 days for Zn.

AGEPC (PAF), at 1.9 x 10(-8) M or higher, induced concentration- dependent aggregation and release in human platelet-rich plasma. Comparative studies with arachidonate, collagen, ionophore, and ADP suggested that AGEPC was a strong stimulus for platelet aggregation and probably a moderate agonist for release, as well as a relatively weak inducer of TXA2 production. The initial phase of AGEPC-induced aggregation was independent of ADP release and TXA2 formation, since it was not inhibited by ASA, apyrase, or CP/CPK. Whereas irreversible aggregation always required ADP release, TXA2 formation was not essential in each instance. Thus, in several experiments, full aggregation responses took place in AGEPC-stimulated platelets that had been pretreated with ASA. AGEPC-induced release of 5-HT, beta - thromboglobulin and PF-4 occurred in parallel and were inhibited by both apyrase and ASA. Washed human platelets did not respond to exogenous AGEPC in the absence of ADP and did not appear to generate significant quantities of AGEPC upon stimulation with thrombin or ionophore.

The distribution of nitrogen (N) was determined on 1238 surface sediment samples (0–3 cm) and 24 cores from Lakes Superior, Huron, St. Clair, Erie, and Ontario. The concentration of N was greatest in the depositional basins of the lakes. The N concentrations decreased sharply from high values at the sediment–water interface to uniformly lower N values at the base of the cores. The surface enrichment was related to increased inputs of N to the lakes since settlement of the region in the order: Lake Ontario > Lake Erie [Formula: see text] Lake Superior > Lake Huron > Georgian Bay.The organic carbon: total nitrogen (C/N) ratios averaged 10.2 in the surface sediments with a range of 5.1 to 66.0. The lowest ratios were found in the depositional basins, with the exception of Lake St. Clair. The magnitude of the C/N ratios was related to the source of the organic matter. Plankton, which are the main source of Org-N in the lakes, accounted for C/N ratios between 7 and 9. Dilution of the modern sediment with organic matter from glacial deposits yielded the higher ratios and low Org-C contents in the nondepositional zones. The high C/N ratios and Org-C contents in Lake St. Clair were believed to be due to a large component of macrophytes in the inputs of organic matter to the lake sediments.

Authentication is the process of verifying a person's claim of identity. The designers of secure computer systems have incorporated many techniques of user-validation from law enforcement, from industrial security, and from the financial community. Several methods have also been developed explicitly for use in computer systems. This paper will present an overview of all methods of authentication currently used in computer security. Implementation considerations will also be discussed.

The kinetics of the acetone-sensitized photoaddition of HBr to ethylene are consistent with the free radical chain mechanism of Vaughan, Rust, and Evans. In the presence of excess propane the combination of bromine atoms (reaction [4]) is the main termination step, and bromoethyl radicals formed by the addition of bromine atoms to ethylene (reaction [2]) are collisionally stabilized. They undergo thermal decomposition (reaction [−2]) or abstract a hydrogen atom from hydrogen bromide (reaction [3a]) to form the product, ethyl bromide. The rate constant ratio, k−2/k3a, increases from 5.6 × 1018 molecules cm−3 at 15.3 °C to 11.5 × 1018 molecules cm−3 at 45.0 °C. This corresponds to E−2 − E3a = 4.5 ± 0.5 kcal mole−1, and is in accord with the thermochemical data. Within experimental error, k2 and k−2 are independent of propane pressure in the range 260 to 390 Torr. Also, [Formula: see text] is equal to 5.5 ± 0.3 × 108 cm3/2 molecule−1/2 s−1/2, independent of temperature over the range 15.3 to 45.0 °C, and E2 = 0.0 ± 0.5 kcal mole−1. In the absence of propane, and at ethylene pressures in excess of 400 Torr, the combination and disproportionation of bromoethyl radicals is the main termination process (reaction [7]). The value of [Formula: see text] is 8.9 ± 0.1 × 10−10 cm3/2 molecule−1/2 s−1/2 at 35.1 °C, in agreement with kinetic data for related reactions.

The rate of combination of bromine atoms in the photosensitized hydrobromination of ethylene has been determined by the rotating sector technique. From this and kinetic data reported previously the rate constant for the addition of bromine atoms to ethylene in the presence of 380 Torr of propane as deactivating gas has been calculated to be 1.5 ± 0.3 × 10−14 cm3 molecule−1 s−1, independent of temperature in the range 15 to 35 °C. This result is discussed and compared with rate constants for other addition reactions to ethylene.

This paper describes a software specification methodology based on the notion of concept specialization. The methodology, which is particularly useful for Information Systems, applies uniformly to the various components of such systems, such as data classes, transactions, exceptions, and user interfaces (scripts), and its goal is the systematic and structured description of highly detailed world models, where concepts occur in many variations. An example from the domain of university information systems is used to illustrate and motivate the approach.

• Over a five-year period we identified 22 term newborns with intracranial hemorrhage by computed tomography in an intensive care unit for newborns. Primary subarachnoid hemorrhage (diffuse or focal) was the most common type of hemorrhage. Diffuse subarachnoid hemorrhage was caused either by traumatic delivery or severe hypoxic-ischemic encephalopathy and caused seizures on the first day. Focal subarachnoid hemorrhage was associated with cerebral infarction. Intraventricular hemorrhage was always accompanied by bloody CSF. Somewhat more than half the newborns with intraventricular hemorrhage had a history of traumatic delivery. In the remainder there were no associated risk factors for the hemorrhage. Hemorrhage into the cerebral hemispheres occurred without any identifiable risk factors. Hemorrhage into the cerebellum was associated with traumatic delivery.

On the possibility that multiple sclerosis is an autoimmune disorder, various immunosuppressive modes of treatment have been tried with conflicting results.

The effect of haemoglobin and albumin-coated charcoal on the concentration of vitamin B12 binding proteins in serum has been investigated. As commonly employed, coated charcoal removes a significant amount of transcobalamin II (TCII) from serum, but does not affect transcobalamin I and III (TCI and III). Increasing the protein coat up to about 10 mg of protein per 25 mg of charcoal reduces the adsorption of TCII, but increasing the protein concentration beyond this has little added effect. The amount of adsorption is proportional to the amount of coated charcoal employed, but even small amounts adsorb some TCII. These results indicate that protein-coated charcoal is not the ideal way of separating free from bound vitamin B12 in serum; it cannot reliably be used for the measurement of the concentration of apo-TCII but can be employed for the measurement of apo-TCI and III.

Summary The incorporation of [3H]uridine into the four species of RNA specified by Sendai virus in monolayers of chick embryo fibroblasts was inhibited to an equal degree by addition of purified chick interferon to cultures before infection with virus. The inhibition of RNA synthesis was dose-dependent. Similarly, [3H]uridine incorporation into RNA of virus nucleocapsid and polyribosomes was completely inhibited by pretreatment with interferon. When interferon was added 2 hr after infection, there were only small effects on the synthesis of total virus-specific RNA and significantly greater reduction was observed in [3H]uridine incorporation into the RNA of nucleocapsid and polyribosomes. Although Sendai infection does not interfere with host-cell protein or RNA synthesis, interferon added 6 hr or later after infection did not affect any Sendai replicative functions.