Mapping air contaminants indoors using a prototype computed tomography system

Single and multiple plumes of sulphur hexafluoride were measured and mapped using a prototype open-path Fourier transform infrared spectrometer (OP-FTIR)-computed tomography (CT) system in an indoor exposure chamber. The OP-FTIR-CT system accurately mapped the position of concentration peaks at different locations in the chamber, and estimated concentrations within a range of 4-50% when compared with point samples measured by gas chromatography with an electron capture detector. Two OP-FTIR spectrometer ray configurations, one with 100 rays and the other with 136 rays, were used to scan the chamber and reconstruct the concentration maps. Ray configuration and time to scan the entire chamber were found to have a profound effect on the quality of the reconstructed maps. The ability to obtain real-time, non-invasive measurements, and to generate spatially and temporally resolved maps of multiple chemicals, makes the OP-FTIR-CT system a promising technique for monitoring source emissions and evaluating exposures to air contaminants in a workplace.

Identification of a 140 kDa protein of rat presynaptic terminal membranes encompassing the active zones

A polyclonal antiserum raised against the carboxy-terminal 17 amino acids of the rat p185c-neu (anct) reacted with a 140 kDa polypeptide in membranes of synaptosome fractions from neocortex and hippocampus of 11-day-old and adult rats. The same antiserum reacted with a 185 kDa polypeptide in microsome membranes from rat pheochromocytoma cells (PC12). By light microscopic immunocytochemistry, the anct antibodies against the 140 kDa protein were localized in the neuropile of brain, cerebellum and spinal cord of 11-day-old and adult rats. Especially prominent staining was obtained in the CA2-CA3 zones of the hippocampus, and in the substantia gelatinosa in the spinal cord. The finely granular and diffuse pattern of the immunostain was consistent with synaptic localizations. Interestingly, antibodies against the entire endodomain of p185c-neu (a-Bacneu) were localized in granular structures, probably representing axo-somatic and axo-dendritic synapses, on a subset of pyramidal neurons of the CA3 zone. By immunoelectron terminals in the giant mossy fiber type in the CA3 and CA4 regions. The immunolocalization of the anct antibodies was restricted in segments of the presynaptic membrane facing the synaptic cleft which include the active zone. The identify and function of the 140 kDa membrane protein of rat brain presynaptic terminals, detected by the anct antibodies, is unknown. The 140 kDa protein may be related to p185c-neu, a tyrosine kinase, or to other known or unknown kinases.

Unexpected transcriptional signals in normal and mitotically defective cells mediated through cytokine and growth factor receptors

Polypeptide growth factors and cytokines mediate their biochemical functions through their responsive receptors. Known cytokine receptors do not possess intrinsic kinase domains whereas several polypeptide growth factor receptors do. Nevertheless, both classes of ligands are capable of activating sets of overlapping genes. In human epidermoid carcinoma cells, for example, both cytokines and epidermal growth factor (EGF) promote a common transcriptional activation signal through the tyrosine phosphorylation of stat91 (signal transducer and activator of transcription) proteins. The stat family of cytoplasmic proteins also appear to have dual functions. Tyrosine phosphorylated 'stats' are employed for signal transduction and, second, for activation of transcription of several genes. The transcription factor-SIE-DNA binding patterns are now known to be different for EGF and interferon-gamma IFN-gamma-treated cells. Nevertheless, in the active DNA-bound complex, the stat91 polypeptide is a component found in either EGF or INF-gamma-treated extracts. Other stat family members of transcription factors may also be present in the complexes. In this case, tyrosine phosphorylated stat91 polypeptides may form into homodimeric or heterodimeric assemblies with other stat-related transcription factors. We describe a novel stat-related factor, p93, that is found in EGF-treated A431 cell extracts but appears to be absent in bovine fibroblast growth factor (bFGF), IFN-gamma, tumor necrosis factor-alpha (TNF-alpha), and untreated cells. p93 appears to be antigenically related to stat91. p185c-neu+, EGFr+ (M1), and p185c-neu- kinase inactive, EGFr+ (NEN757) expressing cells undergo different mitotic responses to EGF. M1 can respond to EGF mitotically while NEN757 cannot. Both cell lines respond to 10 ng/ml of EGF and also to IFN-gamma in transducing transcriptional activation signals to the nucleus, despite the distinct growth response to EGF. Our work has analyzed the stat pathway in these types of cells and found similar patterns of usage despite the distinct EGF-responsive features. Cytoplasmic nonreceptor tyrosine kinases Jak1 and Jak2 may be involved in the activation of stat91 and other transcription factors in EGF and IFN-gamma signaling pathways. Collectively, these studies suggest that the major EGF-stimulated mitotic growth pathways may not be absolutely linked to the stat91 signaling pathways and that such transcription complexes are more complex than previously reported.

A kinase associated with chromatin that can be activated by ligand-p185c-Neu or epidermal growth factor-receptor interactions

Some growth factors transduce positive growth signals, while others can act as growth inhibitors. Nuclear signaling events of previously quiescent cells stimulated with various growth factors have been studied by isolating the complexed chromatin-associated proteins and chromatin-associated proteins. Signals from the plasma membrane are integrated within the cells and quickly transduced to the nucleus. It is clear that several growth factors, such as epidermal growth factor, transforming growth factor alpha (but not transforming growth factor beta), and platelet-derived growth factor, utilize similar intracellular signaling biochemistries to modulate nucleosomal characteristics. The very rapid and consistent phosphorylation of nuclear p33, p54, and low molecular mass proteins in the range of 15-18 kDa after growth factor stimulation implies that there is a coordination and integration of the cellular signaling processes. Additionally, phosphorylation of p33 and some low molecular mass histones has been found to occur within 5 min of growth factor treatment and to reach a maximum by 30 min. In this study, we report that Neu receptor activating factor also utilizes the same signaling mechanism and causes p33 to become phosphorylated. In addition, both the tumor promoter okadaic acid (which inhibits protein phosphatases 1 and 2A) and phorbol ester (phorbol 12-tetradecanoate 13-acetate) stimulate phosphorylation of p33, p54, and low molecular mass histones. However, transforming growth factor beta, which is a growth inhibitor for fibroblasts, fails to increase p33 phosphorylation. In general, p33 phosphorylation patterns correspond to positive and negative mitogenic signal transduction. p33 isolated from the complexed chromatin-associated protein fraction appears to be a kinase, or tightly associated with a kinase, and shares antigenicity with the cell division cycle-dependent Cdk2 kinase as determined by antibody-dependent analysis. The rapid phosphorylation of nucleosomal proteins may influence sets of early genes needed for the induction and progression of the cell cycle.

Prevention of breast tumour development in vivo by downregulation of the p185neu receptor

Certain strains of transgenic mice that express the rat neu oncogene (neuT) in mammary epithelial cells develop breast tumours at an average of 44 weeks of age. In this study, intraperitoneal injection of a monoclonal anti-receptor antibody specific for the rat neuT oncogene product dramatically affected tumour development in these transgenic mice in a dose-dependent manner. A significant proportion (50%) of mice, when injected with anti-receptor antibodies, did not develop tumours even after 90 weeks of age. The phosphotyrosine levels of the membrane fraction of breast tissues in the anti-receptor antibody-treated mice were almost completely abolished when a higher dose of antibodies was used. This study demonstrates, for the first time, that immunologic manipulation of an oncogene product can effectively prevent the development of tumours in a rodent transgenic model.

The neu-oncogene: signal transduction pathways, transformation mechanisms and evolving therapies

A variety of pathways exist to transmit biological signals. One mechanism used for the regulated control of cell growth and differentiation is through the transduction of signals resulting from the binding of soluble polypeptide growth factors to their cognate receptors. The specificity of growth factor action is mediated by the interaction of ligand with cognate receptors which can lead to exquisite control in a tissue- and developmental-specific manner. In addition, individual receptors on the cell surface can form complex assemblies with other receptor/signal transduction molecules that potentially lead to additional levels of signal transmissions. Biological signaling by peptide ligands can be mediated through the enzymatic activation of the receptor resulting in the triggering of a defined biochemical pathway. Ultimately, a mitogenic or differentiation signal is delivered to the nucleus, completing the biological action of the growth factor. The biochemical mechanisms of signal transduction by the p185 neu/c-erbB-2 growth factor receptor and the subsequent physiological responses are the topics of this review. Study of the p185 growth factor receptor has helped to illustrate the functional role of receptor homo- (and hetero-) dimerization in enzyme activation and, in malignant cells, the detrimental results of structural mutations or aberrant gene expression which may effect this dimerization. The ability of one type of growth factor receptor to affect the activity of another (as illustrated by the p185/epidermal growth factor receptor heterodimeric complex) is likely to be a common regulatory feature of growth factor receptor action. The nomenclature to be used in this review will refer to the oncogenic mutated form of the rat protein as 'p185neu', the proto-oncogenic rat protein as 'p185c-neu' and the human form as 'p185c-erbB-2'. The term 'p185' will be used to refer to any type of protein, regardless of the source.

Ligand and p185c-neu density govern receptor interactions and tyrosine kinase activation

The neu protooncogene (also known as c-erbB2, NGL, and HER2) encodes a 185-kDa transmembrane glycoprotein with intrinsic tyrosine kinase activity that resembles the receptor for epidermal growth factor. The p185 gene and protein were originally identified in the brain and are thought to play a critical role in neurogenesis. Aberrant c-erbB2 protein overexpression also occurs in several human adenocarcinomas. A ligand for p185, neu-activating factor (NAF), specifically binds to neu receptor and increases the p185c-neu tyrosine phosphorylation in vitro and in vivo in a dose-dependent manner. We now show that NAF specifically binds to purified p185 expressed in baculovirus. Direct binding analysis showed that NAF binds with high affinity (Kd = 1.3 nM). We have investigated changes in the structure and association state of baculovirus-produced neu holoreceptor that are induced by ligand binding. In this study, we used sucrose gradients to show that purified p185c-neu exists mainly in the monomeric form at low concentrations, whereas at higher concentrations p185c-neu exists as dimers or multimers. At low concentrations, but in the presence of ligand, p185c-neu sediments as a dimeric or multimeric form. Monomer-oligomer interconversion is absolutely ligand dependent at low receptor concentrations. The high molecular weight form of the receptor is enzymatically more active, as a consequence of ligand-driven activation of the receptor kinase. Oncogenic p185neu receptors sediment predominantly as high molecular weight forms and have constitutively active kinases.

Aerobic capacity of the brick-field workers in eastern India

Forty two male brick-field workers of two age groups, viz. 20-29 and 30-39 yrs were studied with a view to determine their aerobic capacity (VO2 max). The average values of VO2 max in l.min-1 showed only small change between the young and the aged groups, but the values of the VO2 max in ml.kg.-1min-1 showed significant difference between the groups due to body weight increase in the aged group. The aerobic capacity of the workers engaged in heavy manual work such as puddlers and load carriers were found to be comparatively higher and a positive significant relationship has been established between the aerobic capacity and different occupations in the brick-field workers.

Is osteoarthritis in women affected by hormonal changes or smoking?

The influence of sex hormone related events and smoking on the development of OA in women was investigated in a case-controlled postal survey. One hundred and twenty-nine patients with nodal generalized osteoarthritis (NGOA) and 145 with non-nodal pauciarticular large joint osteoarthritis (LJOA) were identified from the database of a Nottingham OA clinic. For each patient, three age-matched controls were randomly selected from the same general practice. Sixty-three per cent of questionnaires (690/1096) were returned: NGOA, 95; NGOA controls, 226; LJOA, 113; LJOA controls, 256. There were no differences in age at menarche or menopause, rates of hysterectomy, oral contraceptive use, or hormone replacement use between cases and controls. Fewer OA patients had ever smoked [(Odds Ratio (OR) 0.65, 95% Confidence Interval (CI) 0.45-0.95)] and subset analysis demonstrated that this negative association occurred only in the LJOA group (OR 0.43, CI 0.25-0.72), particularly in those with knee OA (OR 0.29, CI 0.14-0.62). A previous successful pregnancy was negatively associated with NGOA (OR 0.47, CI 0.24-0.95). This study demonstrates no association between oestrogen-related hormonal events and OA, but a negative association between smoking and LJOA. Such data supports the concept that OA is a heterogeneous disease and underlines the need to differentiate OA subsets.

The prevalence of diagnosed systemic lupus erythematosus in whites and Indian Asian immigrants in Leicester city, UK

The prevalence of diagnosed systemic lupus erythematosus (SLE) during 1989 in the adult Indian Asian and White populations of the city of Leicester has been determined. Fifty cases (19 Asian, 31 White) fulfilling the 1982 revised ARA criteria for SLE were identified from a population of 191,469 (37,684 Asian, 153,785 White). Five different sources were used to ascertain cases. The overall prevalence of SLE in Whites was 20.2 per 100,000. Asians of both sexes had a significantly higher prevalence than Whites. Prevalence in males was 31.5 and 7.0 per 100,000 in Asians and Whites respectively; in females the figures were 69.7 and 31.7 per 100,000. Overall, lupus was 3.0 times more common in Asians than Whites. This is the first prevalence study of SLE in Indian Asians and suggests that, like the Black races and the Chinese, they have a greater frequency of SLE than Whites.

Penicillamine in rheumatoid arthritis. A problem of toxicity

Penicillamine has proved an effective second line agent in rheumatoid arthritis. Its use, however, is limited by its toxicity. Long term studies show that only between 30 and 40% of patients started on penicillamine are still taking the drug at 2 years. Toxicity is the chief reason for stopping treatment, the commonest adverse effects requiring cessation of therapy being proteinuria (10 to 13%), skin rashes (5 to 9%), gastrointestinal events (5%) and thrombocytopenia or leucopenia (2 to 5%). A number of autoimmune syndromes may rarely be induced by penicillamine. HLA-B8, Dr3 positive individuals and poor sulfoxidisers are at increased risk of developing toxicity. Meticulous supervision of penicillamine therapy is required to minimise toxicity.

SULPHASALAZINE THERAPY IN RHEUMATOID ARTHRITIS: QUALITATIVE CHANGES IN LYMPHOCYTES AND CORRELATION WITH CLINICAL RESPONSE

Clinical and immunological parameters in 14 patients with rheumatoid arthritis (RA) receiving sulphasalazine (SASP) were evaluated, to determine whether their clinical response was reflected by any quantitative changes in their peripheral blood lymphocytes after 12 weeks. Whilst disease activity markers fell significantly, no such changes were noted in the percentage or absolute numbers of lymphocytes or their subsets. The lymphocytes of a further 21 patients before and after receiving SASP for 12 weeks were then studied qualitatively. The suppression mediated by in vitro SASP on ex vivo PHA stimulated lymphocytes showed a decrease at 12 weeks. This change was more marked and reached statistical significance only in those patients who showed a good clinical response. It is postulated that this may in some way be related to expression of activation markers and concomitant SASP binding.

A comparison of the clinical features and vascular complications of diabetes between migrant Asians and Caucasians in Leicester, U.K

907 consecutive patients, (456 Asian and 451 Caucasian) were assessed, employing a similar methodology to the multi-centre WHO study. The Asians were older at diagnosis (46.5 years compared with 40.6 years, P less than 0.01); they had a shorter duration of diabetes (6.3 years versus 11.4 years, P less than 0.1), a higher rate of diabetes in the first degree relatives (29.5% compared with 16%, P less than 0.1), less ketonuria at presentation (85.3% compared with 47.8%, P less than 0.1), and fewer were treated with insulin (31.4% compared with 68.7%). Comparing the prevalence of complications between Asians and Caucasians, the ischaemic heart disease rate was similar; peripheral vascular disease was less (3.7% Asian, 9.3% Caucasian, P less than 0.05); retinopathy was less (11.6% Asian, 32.3% Caucasian, P less than 0.01) but renal disease was more (22.3% Asian, 12.6% Caucasian, P less than 0.01). After adjusting for age, sex, duration of diabetes, age at diagnosis, hypertension, smoking and treatment with or without insulin, these differences remained significant. Multivariate logistic regression failed to reveal a significant contribution due to any of the above variables, or due to body mass index (BMI), haemoglobin A (HbA1), or physical activity in the prevalence of complications in Asians compared with Caucasians. Marked heterogeneity in the complications of diabetes in the two ethnic groups studied was found, but must be confirmed from population-based studies.

Isolation and characterization of a neu protein-specific activating factor from human ATL-2 cell conditioned medium

The rat neu gene product is a 185 kD membrane bound tyrosine kinase that is closely related to, yet distinct from the epidermal growth factor receptor. The biochemical and cellular effects of a neu protein-specific activating factor (NAF) detected in human ATL-2 cell conditioned medium were recently described (1). To further characterize NAF, some of its physicochemical properties were examined and a method for purifying this factor from ATL-2 cell conditioned medium was developed. In these studies NAF was found to be heat stable and sensitive to the protease chymotrypsin. In addition, a method for purifying this activity was developed using a quantifiable, in vitro autophosphorylation assay system to measure NAF activity in fractions following ion-exchange and then reverse-phase HPLC.

Primary pulmonary hypertension associated with systemic lupus erythematosus

A 24-year-old West Indian woman with a four-year history of systemic lupus erythematosus presented with progressive dypsnoea due to primary pulmonary hypertension. Despite showing a response to vasodilators, these failed to control the condition. Her pulmonary hypertension increased in severity, eventually resulting in her death. We believe primary pulmonary hypertension to be an unusual complication of systemic lupus erythematosus. We suggest that this diagnosis should be considered in all patients with systemic lupus erythematosus and progressive dypsnoea, as optimum benefit can only be obtained by early institution of vasodilator therapy.

Aplastic anaemia in systemic lupus erythematosus: a cellular immune mechanism?

Aplastic anaemia is a rare complication of systemic lupus erythematosus (SLE). The mechanism is unclear but is thought to be related to an autoantibody to bone marrow precursors of haematopoiesis. We report a case of SLE related aplastic anaemia in which therapy with methylprednisolone and high dose cyclophosphamide followed by prednisolone and azathioprine resulted in complete clinical and haematological remission. Bone marrow cultures showed inhibition of erythropoiesis when incubated with acute and remission serum. Myeloid colony growth was not affected by either serum. The serum inhibitor we demonstrated was only active in vitro, and we postulate that the mechanism for marrow aplasia may have been an autoimmune cellular process.

High prevalence of systemic disease and mortality in Asian subjects with systemic lupus erythematosus

All patients with systemic lupus erythematosus (SLE) (American Rheumatism Association criteria with positive antinuclear antibody titre) and who attended any of the three general hospitals in Leicester over a 10 year period were ascertained using several complementary sources. Eighty seven subjects (26 Asian, 61 white) were identified. The estimated prevalence of SLE in Leicester is 0.4/1000 for Asian and 0.2/1000 for white subjects. Mean age of onset of the disease was 24 years in Asian and 31 years in white subjects, with both groups showing a female preponderance. Proteinuria (greater than 1 g/24 h) was noted in 15 (58%) Asian and 21 (35%) white subjects; neuropsychiatric disease in 10 (38%) Asian and 8 (13%) white subjects; myalgic symptoms with raised muscle enzymes in 9 (35%) Asian and 3 (5%) white subjects. Nineteen (73%) Asian subjects were positive for extractable nuclear antigens as well, at some stage of their disease, compared with 6 (10%) white subjects. Immunosuppressive treatment was required in 12 (46%) Asian and 12 (20%) white subjects, and deaths of seven Asian and five white subjects were attributed to SLE. These findings show that Asian subjects have a higher prevalence of SLE with greater systemic disease and mortality.

An audit of patients attending a general medical follow-up clinic

Of the 418 consecutive patients attending a general medical clinic for follow-up, 113 (27%) had appointments in another medical clinic for the same or a related problem; 98 of them (87%) were attending a clinic in a different hospital. The reasons for multiple clinic attendance were routine follow-up after hospital admission in 55 (49%), referrals from general practitioners to more than one clinic in 33 (30%), and cross-referrals from the 'parent' medical firm in 19 (17%). In six patients no clear reason for multiple attendances could be identified. More than half (55%) were over 65 years old, 45% lived more than five miles from the hospital, and 78% depended on ambulance, friends, or relatives for transport. We suggest that follow-up attendances at outpatient clinics should be stringently reviewed and should only be maintained if a clear reason can be identified. This would not only ensure a more effective service overall but would also save patients and relatives from inconvenience.

Gastric hemorrhage and Kaposi's sarcoma treated with radiotherapy

A 66-year-old man, with advanced alcoholic liver disease with Kaposi's sarcoma involving the stomach and the skin of the lower extremities, developed upper gastrointestinal hemorrhage. He was treated with radiation therapy to the stomach and the skin with rapid resolution of the gastric lesions, as demonstrated by serial endoscopy.

Primary meningococcal arthritis associated with adult respiratory distress syndrome

A previously fit and well 20 year old man with primary meningococcal arthritis of the left knee is described. Despite intensive search there was no evidence of extra-articular meningococcal infection. He subsequently developed adult respiratory distress syndrome as a rare and previously undescribed complication.

Peripheral neuropathy, polymyalgia and arthralgia: a paraneoplastic syndrome associated with myeloma

We describe a patient with peripheral neuropathy, polymyalgia, arthralgia and cervical vertebral osteosclerosis who was subsequently diagnosed to have fatal multiple myeloma with IgG gammopathy and lambda urinary chains. The initial presentation and clinical features are discussed.

A clinical audit of thallium-technetium subtraction parathyroid scans

Eighty six consecutive thallium-technetium subtraction parathyroid scans performed over a three year period for hypercalcaemia have been evaluated. Twelve had chronic renal failure, 11 had hypercalcaemia due to non-hyperparathyroid causes and in 10 the imaging study was technically inadequate. The remaining 53 technically adequate studies performed for hypercalcaemia clinically thought to be possibly due to hyperparathyroidism have been analysed. Of 20 (38%) positive scans, 13 came to surgery (10 correctly localized parathyroid adenomas, 2 with multiple gland hyperplasia, and 1 papillary carcinoma of the thyroid). Of 33 (62%) negative scans, 9 had surgical exploration on the basis of strong clinical grounds and all had parathyroid adenomas. Multiple biochemical parameters have been assessed in relation to a positive outcome on scan. The adjusted calcium-phosphate product and the ratio of the adjusted calcium-phosphate product to creatinine (Ca x P/Cr) were both significantly lower in the scan positive group (P less than 0.01). The scan positive group had a significantly higher mean level of PTH (P less than 0.001) and lower mean level of phosphate (P less than 0.001). The present experience shows that parathyroid imaging is useful in localizing parathyroid adenomas in 50% of cases (10 out of 19). This figure is at the lower end of the range of previously published results. It is less effective in demonstrating multiple gland hyperplasia. The decision as to whether to undertake surgical exploration when the scan is negative has been based successfully on clinical judgement. We feel that an analysis of this nature is important, as it gives insights into the practical relevance of parathyroid imaging in the context of routine clinical work.

Accidental self administration of xylazine in a veterinary nurse

A 19 year old male veterinary nurse accidentally injected himself with 200 mg of xylazine (a muscle relaxant and sedative used in veterinary practice). He subsequently became comatose, hypotensive, bradycardic and acidotic. He required intensive supportive therapy, and made a full recovery over the next few hours. Xylazine toxicity in humans is very rare, and the effects are discussed.

Campylobacter pylori colonization factor shows specificity for lactosylceramide sulfate and GM3 ganglioside

The specificity of Campylobacter pylori cell surface lectin, a presumptive colonization factor, was investigated using various sulfated and sialic acid containing glycolipids. C. pylori cells, cultured from human antral mucosal biopsies, were incubated with intact and modified glycolipid preparations and examined for agglutination inhibition of human erythrocytes. Titration data revealed that the inhibitory activity was highest with lactosylceramide sulfate and GM3 ganglioside, while galactosylceramide sulfate GM1, GD1a and GD1b gangliosides were less effective. A strong inhibitory activity towards C. pylori hemagglutin was also observed with an antiulcer agent, sucralfate. The inhibitory effect of both types of glycolipids was abolished by the removal of sialic acid and sulfate ester groups, thus indicating that sulfated and sialic acid containing glycolipids with terminal lactosyl moieties serve as mucosal receptors for colonization of gastric epithelium by C. pylori.

Glucose tolerance during pregnancy in Asian women

The present study was aimed at examining differences in gestational diabetes mellitus (GDM) between two ethnic populations (immigrant Asians and indigenous White Caucasians) residing in Leicester, U.K. The study was divided into two parts: to determine the prevalence of GDM and to determine the level at which glycaemia may impose a risk to the mother and the foetus. Of a total of 12,005 pregnancies (4561 Asian and 7444 White Caucasian), over a 3-year period, 314 (6.8%) Asian and 504 (6.7%) White Caucasian were given a 75-g oral glucose tolerance test (OGTT) at 28-32 weeks for indications of 'large for date' pregnancies, hydramnios, glycosuria, a history of previous abortions, stillbirths, congenital abnormalities or glucose intolerance, and family history of diabetes. Abnormal glucose tolerance (AGT) was taken as a 2-h venous plasma glucose greater than or equal to 7.8 mmol/l which reverted to normal when formally tested during the puerperium (WHO criteria, 1985). AGT was found in 1.38% Asian and 0.87% White Caucasian pregnancies (P less than 0.01). This was further divided into impaired glucose tolerance (IGT) (2-h value 7.8-11.1 mmol/l) and gestational diabetes mellitus (GDM) (2-h value greater than or equal to 11.1 mmol/l). IGT was found in 1.2% Asian and 0.84% White Caucasian pregnancies (P less than 0.01), and GDM in 0.18% and 0.02% respectively (P less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Diabetes mellitus as a risk factor for acute myocardial infarction in Asians and Europeans

Ischaemic heart disease is commoner among immigrants from the Indian subcontinent than among Europeans in the United Kingdom. The excess cannot be accounted for by differences in smoking, blood pressure, or lipid concentrations. There is, however, an increased prevalence of diabetes mellitus in the Asian population. Separate estimates of the relative risk of acute myocardial infarction associated with diabetes from parallel case-control studies were made to compare the importance of diabetes as a risk factor in the two ethnic groups. For Asians the relative risk was 3.3 (95% confidence interval 1.9 to 5.8) and for Europeans 1.3 (1.0 to 1.7). Calculations of population attributable risk indicated that clinical diabetes mellitus accounts for 21% of the incidence of myocardial infarction in Asians but only 3% of the incidence in Europeans. Diabetes mellitus is of sufficient quantitative importance as a risk factor to account for the whole of the observed excess of deaths from ischaemic heart disease among Asians in the United Kingdom.

The effects of high dose inhaled beclomethasone dipropionate on glucose and lipid profiles in normal and diet controlled diabetic subjects

We determined the effect of high doses of inhaled beclomethasone dipropionate (2000 micrograms day-1 for two weeks) on the glucose tolerance test, insulin levels, fasting cholesterol and triglyceride concentrations in fourteen normal and ten elderly diet controlled diabetic patients, in a single blind, placebo controlled trial. No significant disturbance of glucose or lipid metabolism was found in either group. This study suggests that at this high dose, BDP does not exhibit significant disturbance of glucose and lipid metabolism after two weeks use.

Possible physiological role of myocardial fatty acid binding protein in phospholipid biosynthesis

Accumulation of free fatty acids and their esters resulting from the degradation of membrane phospholipids is one of the major causes for the myocardial dysfunction during ischemia and reperfusion. In this communication, we have studied the possible physiological role played by fatty acid binding protein (FABP) in stimulating key enzymes involved in phospholipid biosynthesis. Purified rat heart FABP bound a maximum of either 2 mol of [1- 14C]palmitoyl coenzyme A (CoA), oleoyl CoA, or oleic acid per mol of FABP as observed by Scatchard analysis. FABP caused a threefold increase in the incorporation of [1- 14C]palmitoyl CoA into phosphatidic acid as compared to only a 1.5-fold increase by bovine serum albumin (BSA). Myocardial FABP also enhanced acyl CoA monoacylglycerophosphorylcholine acyl transferase minimally at a substrate concentration (greater than 200 microM), the activity of this enzyme was enhanced 4.5- and 2-fold by FABP and BSA, respectively. The maximum stimulation of the enzyme activity took place at the fatty acyl CoA concentration where inhibition of the enzyme activity is usually observed due to the surfactive property of acyl CoAs. These results thus indicate that under abnormal pathophysiological conditions such as ischemia, when acyl CoA concentration increases, FABP may protect acyl CoA monoacylglycerophosphorylcholine acyl transferase as well as stimulate glycerophosphate acyl transferase to limit the loss of membrane phospholipids, suggesting a possible role of FABP in phospholipid biosynthesis.

Time-resolved nanosecond and picosecond absorption studies of excited-state properties of 1-thiobenzoylnaphthalene

1-Thiobenzoylnaphthalene (TBN), known for its pericyclization reaction from the lowest excited singlet state (S1), has been subjected to nanosecond and picosecond laser flash photolysis studies. The two major transients observed in the course of nanosecond laser pulse excitation are (i) the short-lived triplet characterized by two absorption maxima (400–410 and 740–750 nm) and submicrosecond intrinsic lifetimes (80–130 ns) and (ii) a relatively long-lived species (λmax = 520 nm and τ = 220–240 ns). Various triplet-related photophysical data of TBN, including self-quenching and bimolecular quenching rate constants, have been determined. The existence of a photochemical path from S1 manifests itself in low intersystem crossing quantum yields, particularly in the polar/hydrogen-bonding solvent, methanol. From the build-up of the triplet under picosecond excitation into S1 the lifetime of the latter is estimated to be ≤ 50 ps (in benzene). The fast intrinsic decay of TBN triplet is attributable to facile intra- and intermolecular photochemistry. The 520 nm transient species could not be definitively assigned, except that it is neither a triplet nor a triplet-derived product and that it arises via photochemistry from S1. Keywords: laser flash photolysis, triplet, transients, absorption maxima, lifetimes, quenching rate constants, photochemistry, 1-thiobenzoylnaphthalenes.

Free radical scavenging by myocardial fatty acid binding protein

Recent investigations have indicated the presence of a fatty acid binding protein (FABP) in mammalian heart. This protein binds free fatty acids and their esters with high affinity, however, its physiological role remains unknown. Since FABP constitutes a significant amount of cystolic protein, it is likely that it would be a target for free radical attack. To test this hypothesis, FABP was examined for scavenging against free radicals such as the superoxide anion (O2-), hydroxyl radical (OH.) and hypochlorite radical (OCl.) which may be present in an ischemic reperfused heart. Our results suggest that FABP scavenges O2-, OH. and OCl. as indicated by the FABP inhibition of O2- -dependent reduction of cytochrome c, OH.-dependent hydroxybenzoic acid formation and OCl.-mediated chemiluminescence response. FABP was found to be a more potent scavenger of these free radicals compared to bovine serum albumin. Furthermore, FABP was more effective in scavenging OH. than O2-, and inhibited OH. mediated lipid peroxidation process. These results indicate that FABP can scavenge free radicals which may be present in an ischemic/reperfused heart and, thus, may play a significant physiological role in the heart during ischemia and reperfusion.

Separation of fatty acid binding protein by high-performance mixed-mode chromatography

Fatty acid binding protein (FABP) (14 kDa), can regulate the levels of tissue free fatty acids by binding them with high affinity. Since free fatty acids are known to accumulate in the ischemic myocardium, it is likely that FABP has a significant role in regulating their concentration in ischemic heart. FABP has recently been purified from other proteins, but the method requires several hours and special techniques. In this report, we describe a rapid high-performance liquid chromatographic method for separating and isolating the FABP from myocardial tissue biopsies. About 25-50 micrograms of rat heart cytosol was incubated with 2 nmol of the potassium salt of [9,10-3H]oleate (25,000 cpm) for 10 min at 37 degrees C. This was then injected onto a Bio-Rad (Richmond, CA, U.S.A.) TSK-125 column. The sample was run using a low-salt isocratic mobile phase containing 10 mM potassium phosphate buffer (pH 7) and 1 mM dithiothreitol, and at a flow-rate of 0.8 ml/min. The heart cytosol, when incubated with isotopic oleate, was resolved into two radioactive peaks, one eluting in the area of serum albumin (retention time 9.6 min) and the other corresponding to a retention time of 12.9 min. The sodium dodecyl sulfate polyacrylamide gel electrophoretic profile of the later peak revealed a major protein band of ca. 14 kDa. Rat heart FABP purified by gel filtration and ion-exchange chromatography coeluted with the second radioactive peak.(ABSTRACT TRUNCATED AT 250 WORDS)