Risk factors for hyperinflation in young schoolchildren born prematurely

Lung function abnormalities, including hyperinflation, are common in young children born prematurely. The aim of this study was, in such patients, to determine factors associated with hyperinflation, that is an elevated lung volume. Lung volume was estimated by measuring functional residual capacity (FRC) before and after bronchodilator therapy in 41 5-year-old children who had been born prematurely at a median of 30 weeks gestational age. Hyperinflation was defined as an FRC greater than 120% of that predicted for height and a positive bronchodilator response as a greater than or equal to 10% change in FRC. Twelve (29%) of the children were symptomatic at 5 years, their median FRC (132%) was significantly higher than that of the asymptomatic children (109%), P < 0.01). Twelve (29%) children were hyperinflated; a greater proportion of the hyperinflated compared to the non-hyperinflated patients were symptomatic at 5 years (7 or 58% versus 5 or 17%) (P < 0.05) and responded to bronchodilator therapy (9 or 75% versus 4 or 14%) (P < 0.01). Regression analysis demonstrated that hyperinflation related significantly only to current symptom status, but not perinatal variables.

CONCLUSION

Hyperinflation in young children born prematurely reflects current symptom status and not adverse neonatal events.

Perinatal lung function and invasive antenatal procedures

BACKGROUND

Second trimester amniocentesis has been associated with an excess of perinatal lung function abnormalities. Early amniocentesis might have a similar adverse effect, as could other invasive investigations carried out in the first trimester.

METHODS

Plethysmographic measurements of thoracic gas volume (TGV) and airway resistance (Raw), from which specific conductance (sGaw) was calculated, were made in the perinatal period in non-sedated infants. In addition, functional residual capacity (FRC) was measured using a helium gas dilution technique. Measurements were made in 47 infants whose mothers had undergone early amniocentesis, 19 whose mothers had undergone chorion villus sampling, and 25 controls whose mothers had undergone no invasive antenatal procedures.

RESULTS

The infants of mothers who had undergone early amniocentesis had higher TGV (95% CI -6.3 to 1.1 ml/kg) and Raw values (95% CI -10.68 to -5.23 cm H2O/l/s) and lower sGaw (0.11 to 0.84 l/cm H2O.s) and FRC (-5.17 to - 0.87 ml/kg) values than the controls. Infants whose mothers had undergone chorion villus sampling also differed significantly from the controls with higher Raw (-7.59 to -1.99 cm H2O/l/s) and lower sGaw values (0.11 to 0.24 l/cm H2O.s), and had lower Raw values than those in the early amniocentesis group (not significant). Logistic regression analysis, taking into account possible risk factors for abnormal lung function, showed that the procedures performed in the first trimester were independently associated with a high airways resistance.

CONCLUSION

These results suggest that invasive procedures performed in the first trimester of pregnancy have an adverse effect on perinatal lung function.

In vitro effect of gold sodium thiomalate and methotrexate on tumor necrosis factor production in normal healthy individuals and patients with rheumatoid arthritis

We studied the in vitro action of gold sodium thiomalate (GSTM) and Methotrexate (MTX) on spontaneous and lipopolysaccharide (LPS) stimulated TNF alpha production by peripheral blood mononuclear cells (PBMC) of patients with rheumatoid arthritis (RA) and normal healthy individuals. GSTM and MTX (10 microg) each were added to the cultures of PBMC either in medium alone (spontaneous) or in the presence of 10 microg of LPS. GSTM and MTX augmented spontaneous TNF alpha production in normal individuals and patients with RA but did not influence LPS stimulated TNF alpha production. However, TNF alpha production by the PBMC of normal individuals was inhibited if the PBMC were stimulated with LPS, for 6 or 12 h, washed to remove LPS and subsequently incubated with GSTM. These data indicate that GSTM can inhibit TNF alpha production when the PBMC are preactivated by LPS.

The effect of blood transfusion on oxygenation in premature ventilated neonates

The effect of blood transfusion to maintain a preset packed cell volume (PCV) level in preterm ventilated infants has been investigated. Fifty infants, median gestational age 26 (range 23-33) weeks and postnatal age 4 (1-29) days, transfused a median of 15 ml/kg of blood in response to a PCV < or = 40% were retrospectively identified and their medical records reviewed to determine the change in PCV and haemoglobin resulting from the transfusions. In addition, their mean airway pressure (MAP) was noted and, as an index of oxygenation, their oxygenation index (OI), alveolar/arterial oxygen gradient (AaDO2) and arterial/alveolar (a/A) ratio calculated 12 h, 6 h and immediately prior to the transfusion and immediately post, 12, 18 and 24 h after the transfusion. The transfusion improved the PCV and haemoglobin (P < 0.0001). No significant changes in MAP or level of oxygenation were experienced in the 12 h prior to the transfusion. Post transfusion, despite no significant change in MAP, the AaDO2 OI and a/A ratios compared to immediately prior to the transfusion were significantly better at 12, 18 and 24 h.

CONCLUSION

It is useful to transfuse ventilated preterm infants to maintain their PCV above a preset level.

Characterization of membrane-bound and membrane anchor-less forms of hemagglutinin glycoprotein of Rinderpest virus expressed by baculovirus recombinants

The Rinderpest virus (RPV) hemagglutinin (H) is a class 2 glycoprotein by means of which the virus attaches to the host cell receptor. A full length cDNA coding for H protein was used to construct a recombinant baculovirus expressing the H protein, recH(M), on the surface of insect cells. The small N terminal cytoplasmic domain was deleted and the transmembrane domain which extends from amino acids 35 to 59 was replaced with a signal peptide derived from the ecdysteroid UDP glycosyl transferase (egt) gene of the baculovirus, AcNPV. The protein recH(sec) expressed by the recombinant baculovirus carrying this engineered gene was secreted into the medium. Both forms of recombinant H protein retained reactivity with conformation-dependent monoclonal antibodies. The recH(M) was recognized by antibodies made in cattle either as the result of vaccination or natural infection. The soluble form of H is a valuable tool for studying the structure and function of the RPV H glycoprotein.

Prediction of morbidity during infancy after repair of congenital diaphragmatic hernia

Recent studies have suggested there may be a high incidence of pulmonary and extrapulmonary sequelae among infants who have undergone repair of congenital diaphragmatic hernia (CDH). The aim of this study was to identify factors that predict high-risk cases to facilitate counseling of parents. Morbidity, defined as conditions requiring treatment and/or hospitalization during follow-up, was documented. Only five of 15 cases that had been diagnosed antenatally (at 16 to 26 weeks' gestation) and underwent surgical repair after preoperative stabilization were without morbidity at the time of follow-up. Respiratory problems were identified in seven (chylothorax in 3, recurrent infections in 4) and failure to thrive in four; three infants required further gastrointestinal surgery. A comparison of infants with and without morbidity showed that the only significant difference between the groups was in the duration of respiratory support. A requirement for respiratory support for more than 10 days had 90% sensitivity, 100% specificity, and a positive predictive value for morbidity at follow-up of 100%.

Urinary excretion of adrenocortical steroid metabolites by pre-term human infants: trends from birth until 3 months post term

We report trends in urinary steroid excretion in serial 24 hour collections made using a novel method based on "Supersorb" type disposable nappies. Using capillary column gas chromatography, we quantified nine cortisol metabolites (FM) and 11 steroid sulphates (SM) in 6 infants born at 29-31 weeks gestation on 9 occasions until 24 weeks post delivery. In all infants, SM excretion increased progressively until 33-39 weeks (mean 36.8) post conception to maxima of (all values mg/24 h) 2.6-11.7 and then declined to 5-15% of peak values at the end of the study period in 4 infants born after a period of labour but to only 54 and 71% in 2 infants born without labour. FM levels showed a wide range which was not correlated with body weight, eg: on week 1, 0.06-0.20 and on week 24, 0.15-0.72. progression over this period was essentially linear. The ratio (mean (SD)) of 11-oxo/11-hydroxy metabolites decreased from 10.0 (8.2) to 2.3 (0.4) in the same period, p = < 0.10, while that of 20-oxo/20-hydroxy metabolites increased from 0.18 (0.07) to 1.08 (0.42), p = < 0.04. The ratio of metabolites with 5 oxygen functions relative to 6 increased from 0.38 (0.16) to 1.36 (0.43), p = < 0.04. Excretion of 5 alpha-tetrahydrocortisol began to rise at 44-47 wk post conception, but, unexpectedly, that of the 5 beta epimer began to rise sooner, at 39-41 wk, reaching a peak at 44-51 wk and then declining. The ratio of 5 beta/5 alpha epimers was 11.71 (11.1) at the peak and 1.14 (0.87) at 24 weeks, p = < 0.07. We conclude that, using a collection method which is reliable, non-stressful and repeatable at frequent intervals, new information on the evolution of steroid secretion and metabolism postpartum is emerging.

Flow cytometric characterization of isolated porcine hepatocyte suspensions for liver support

The high yield hepatocyte isolation necessary for hybrid liver assist devices (LAD) unavoidably increases contamination by nonparenchymal cells and depresses hepatocyte viability and functions. We have developed a flow cytometric procedure that improves quality control of the isolations. Cells present in these preparations were labeled by immunofluorescent antibody staining against cytokeratin 8, 18 as well as vimentin to identify hepatocytes, fibroblasts, and endothelial cells. Antibody staining against albumin and carbamoylphosphate synthetase allowed assessment of levels of albumin and carbamoylphosphate synthetase based on the hepatocyte relative fluorescence intensity. Hepatocyte P450 enzyme activity was measured by its ability to convert 5,6-methoxycarbonylfluorescein, a nonfluorescent substrate, to an intracellular fluorescent product. Flow cytometric methods of cell type identification and cell function assessment are fast and accurate and can be applied to commercial cell production. They may also provide an avenue for the enrichment of otherwise heterogeneous hepatocyte suspensions with cells presenting the specific functions desired for an hybrid liver assist devices.

Post-transfusion hepatitis type B following multiple transfusions of HBsAg-negative blood

BACKGROUND/AIMS

Post-transfusion hepatitis continues to occur, though with decreasing frequency, even after screening donor blood for HBsAg, anti-HBc, anti-HCV and alanine aminotransferase activity. Data from developing countries on the frequency and type of post-transfusion hepatitis are scarce. We undertook this prospective study to determine the incidence and type of post-transfusion hepatitis at our center after transfusion of blood negative for HBsAg by ELISA.

METHODS

Forty-one patients undergoing open-heart surgery, who had received 3 or more units of HBsAg-negative blood, were followed up. Serum samples of donor units transfused to recipients who developed post-transfusion hepatitis-B were subjected to HBV DNA amplification by the polymerase chain reaction, using two sets of X-gene specific primers which amplified a 250-bp fragment of the HBV DNA.

RESULTS

We found that six of the 41 patients (14.6%) developed post-transfusion hepatitis; four of them (66.6%) developed icteric post-transfusion hepatitis B, whereas two (33.3%) developed anicteric post-transfusion hepatitis C. These six recipients received a total of 48 units of blood and 30 of these 48 units could be subjected to HBV DNA amplification by polymerase chain reaction. Eleven donor samples were polymerase chain reaction positive and had been transfused to three of the four patients who had developed post-transfusion hepatitis B.

CONCLUSIONS

We conclude that post-transfusion hepatitis B continues to be the most common cause of post-transfusion hepatitis in India. Screening of donor units for HBsAg by ELISA does not exclude all blood units infectious for hepatitis B virus. Additional measures to ensure safety of blood supply should be sought.

The Hering-Breuer reflex in ventilated children

The authors tested the hypothesis that, in the paediatric population, the Hering-Breuer reflex would be provoked by the positive pressure inflation of mechanical ventilation (IPPV), and that the strength of the reflex would relate to the child's age and compliance of the respiratory system (CRS). During IPPV, changes in air flow, volume and airway pressure were recorded simultaneously. From the traces, expiratory times and CRS were calculated. The mean expiratory time (Te1) prior to each inflation and the mean expiratory time (Te2) immediately following an inflation were determined. The presence of the reflex was indicated by Te2 being longer than Te1, and the strength of the reflex was calculated as the difference between Te2 and Te1 expressed as a percentage of Te1. Twenty children were studied who had a mean age of 0.7 years (range 0.1-9.8 years). The reflex was provoked in 19 of the 20 patients and was not seen in the oldest patient. The strength of the reflex varied from 22 to 144% and was inversely related to postnatal age significantly (r = -0.73) but not CRS or inflation volume. It is concluded that the Hering-Breuer reflex is provoked during IPPV in young children; whether, as in neonates, this influences the efficacy of ventilation deserves investigation.

Takayasu's arteritis: role of Mycobacterium tuberculosis and its 65 kDa heat shock protein

BACKGROUND

Mycobacterium tuberculosis has been implicated in the pathogenesis of Takayasu's arteritis (TA). Recently, its 65 kDa heat shock protein (HSP) has been implicated in the pathogenesis of other autoimmune diseases. We thus decided to study humoral immune response to Mycobacterium tuberculosis antigens in patients with TA.

AIM

To study humoral immune response to Mycobacterium tuberculosis and its 65 kDa HSP, a putative autoantigen, in patients with TA.

METHODS

Antibodies to sonicated Mycobacterium tuberculosis extract (MBA) and its recombinant 54 kDa protein were measured using ELISA in 36 patients with TA and 35 healthy controls. Levels exceeding mean +2 S.D. of the controls were taken as positive responses.

RESULTS

Abnormally elevated levels of IgG, IgM and IgA antibodies against MBA were present in 6, 20 and 7 patients respectively whereas those against r65 kDa protein were present in 6, 7 and 33 patients, respectively. Though the levels of IgG antibodies were also elevated, those of IgM and IgA antibodies were elevated to a greater extent.

CONCLUSIONS

Patients with TA have heightened immune response to Mycobacterium tuberculosis antigens, in particular to its 65 kDa HSP, suggesting that this organism may have a role in the immunopathogenesis of this disease.

The prevalence of transfusion transmitted diseases in renal transplant recipients

Majority of renal transplant patients have history of blood transfusion. Out of a total of 120 renal transplant patients, 20 (16.6%) patients showed raised alanine aminotransferase (ALT) levels (> 45 IU) on 2 or more occasions at 2 weeks interval. This study was undertaken to estimate the risk of transfusion transmitted diseases (TTD) in these 20 renal transplant patients. Another 200 voluntary blood donors were also included as control. Both subject groups were screened by ELISA for HBsAg, anti HBc (IgG & IgM), anti HCV, anti CMV (IgM), anti HIV and VDRL tests for syphilis. A total of 11 (55%) patients and 3 (1.5%) blood donors showed the evidence of HBsAg positivity (p < 0.01). Anti HBc antibody was present in 12 (60%) patients and 39 (19.5%) donors which was significantly (p < 0.01) different. Anti HCV antibody was detected in 5 patients and in one blood donor (p < 0.01). However, anti CMV antibody was present in 4 (20%) patients and 3 (1.5%) donors, respectively. There was no evidence of HIV and syphilis infection in both these groups. High incidence of hepatitis markers were observed in renal transplant patients.

Infective endocarditis of the tricuspid valve in an orthotopic heart transplant recipient

A 43-year-old orthotopic heart transplant recipient had coagulase-negative staphylococcus endocarditis 26 weeks after the operation. A diagnosis of endocarditis was confirmed and followed up by serial transoesophageal echocardiography. Treatment with intravenous gentamycin and vancomycin cured her endocarditis, and a 2.5 cm vegetation regressed significantly. She has been well since and, at 14 months after transplantation, was back to her normal activities. Although repeated blood culture yielded only intermittent light growths of coagulase-negative staphylococci, there were several positive samples. In a setting of infective features, light growths of coagulase-negative staphylococcus should be taken seriously if repeatedly positive in heart transplant recipients or other immunocompromised patients. Transesophageal echocardiography offers significant advantages over the transthoracic modality in suspected endocarditis.

Immunoproliferative small intestinal disease: a frequently missed diagnosis

Immunoproliferative small intestinal disease (IPSID) is a poorly recognized cause of malabsorption syndrome in India. Clinicopathological features of five patients with IPSID seen over a two-year period are described. Our data suggest that IPSID is commonly misdiagnosed as intestinal tuberculosis due to lack of awareness and reluctance to obtain small bowel biopsies. Empirical institution of anti-tubercular chemotherapy not only leads to delayed diagnosis but also possibly alters the natural history of the disease, resulting in an intermediate phase of amelioration followed by a terminal phase of lymphomatous transformation. The disease is therefore usually diagnosed at an advanced stage and hence is associated with a relatively poor outcome.

Tissue-specific expression of the human pyruvate dehydrogenase alpha (Pdha-1)/chloramphenicol acetyltransferase fusion gene in transgenic mice

A chimeric gene (-763/+33Pdha-1/CAT) containing -763/+33 nucleotides o f the human pyruvate dehydrogenase gene (Pdha-1) and the structural gene of chloramphenicol acetyltransferase (CAT) was used to generate transgenic mice. CAT activity was detected predominantly in the brain followed in decreasing order by adipose tissue, spleen, heart, kidney and liver. Developmental expression of CAT activity in the testes was similar to that of the endogenous Pdha-1 subunit expression in the testes. Dietary regulation of the transgene was comparable to the expression of endogenous pyruvate dehydrogenase complex in kidney and adipose tissue. Thus, the -763/+33 bp segment of the human Pdha-1 gene is transcriptionally active in vivo and can direct the expression of CAT in several tissues.

Isolation and culture of porcine hepatocytes for artificial liver support

The primary requirement of cells in a liver support system is the preservation of the in vivo metabolic functions that prevent or decrease the progress of hepatic encephalopathy (HE) by providing interim support to liver failure patients. While rodent hepatocytes offer a model for liver assist device (LAD) research, their limited number per animal prohibits direct scale up to human devices. Healthy human liver cells are seldom available in adequate numbers to support clinical LAD use; consequently, a large animal source of liver cells is needed. The study presented here explored the potential of porcine hepatocytes to proliferate and maintain metabolic function in vitro. Porcine hepatocytes were isolated from approximately 12 kg swine by a modification of Seglen's method. Hepatocytes cultured up to 10 days were shown to metabolize ammonia and maintain both Phase I and II detoxification functions. In addition, the cultures showed proliferative activity both as an increase in total protein content and by thymidine incorporation. Immunocytochemical staining identified cell proliferation through Day 4 to be primarily hepatocytes while Days 6 and 10 showed nonparenchymal cells to be increasing. The detoxification functions measured showed peak activity on Day 4 and gradually declined through Day 10. The ability of porcine hepatocytes to proliferate and maintain a diversity of hepatic functions in culture strongly suggests their potential for use as the biological component of artificial LADs.

Defective lymphoproliferative responses & interleukin-2 production in chronic renal failure patients

Cellular immune responses were evaluated in 12 early renal failure (ERF) patients who were not on maintenance haemodialysis, 43 end stage renal disease (ESRD) patients on haemodialysis (HD) and 25 healthy volunteers. Peripheral blood mononuclear cells (PBMC) of ERF and ESRD patients on HD had a significantly diminished lymphoproliferative responses to phytohaemagglutinin and a monoclonal antibody to the CD3 (anti-CD3) receptor on T-cells as compared to normals. The interleukin-2 (IL-2) production by the PBMC was also significantly reduced in renal failure patients as compared to normals. These data suggest that both IL-2 dependent and IL-2 independent T-cell functions are defective in renal failure patients.

Inferoposterior ventricular septal rupture: repair with maintenance of ventricular geometry

We present a method of repairing inferobasal ventricular septal rupture after myocardial infarction, preserving the ventricular cavity sizes. This may be useful when extensive infarction compromises ventricular geometry with other repair techniques.

Gene regulation and genetic defects in the pyruvate dehydrogenase complex

The mammalian pyruvate dehydrogenase complex (PDC) is subject to both short-term (product inhibition and covalent modification) and long-term (increases in total activity and protein mass) regulation mediated by dietary and hormonal treatments. Recent advances in the isolation and characterization of the complementary DNAs as well as genes encoding several components of mammalian PDC have facilitated studies concerning long-term regulation of PDC. Analyses of the promoter-regulatory regions of the two human PDC genes show characteristics of both facultative and housekeeping gene promoters, indicating complex transcriptional regulation. Deficiency of PDC activity causes a wide range of neurological disabilities. A spectrum of genetic defects in PDC components has been reported; however, the most frequent defects are associated with the pyruvate dehydrogenase component. Heterogeneity in pyruvate dehydrogenase deficiency has been shown to occur at both protein and messenger RNA levels, and several mutations in pyruvate dehydrogenase have been identified. Dietary treatments such as ketogenic diets and vitamin supplements as well as dichloroacetate treatment have been utilized to treat PDC deficiency, but their efficacy requires further evaluation.

Effectiveness of mandatory transmissible diseases screening in Indian blood donors

This study was undertaken to determine the prevalence of transfusion transmitted diseases (TTDs) among local blood donors, the safety offered by the four mandatory tests (for HIV, HBsAg, syphilis and malaria) and to assess alanine aminotransferase (ALT) as a surrogate test. A total of 313 blood donors were tested for HBsAg, hepatitis B core (HBc) antibody, hepatitis C (HCV) antibody, HIV antibody, and IgM antibody to cytomegalovirus (CMV-IgM). The serum alanine aminotransferase levels were also done on each unit of blood. The prevalence of various markers was 7(2.2%) for HBsAg, 57 (18.2%) for anti HBc (total), 1 (0.3%) for anti HCV, 16 (5.1%) for anti CMV. None of the donors were positive for HIV, VDRL or malaria. ALT level was raised in 16.5 per cent of donors and showed no correlation with hepatitis markers. ALT was not found to be useful as a surrogate marker for routine screening of donors. Sensitive tests like ELISA and immunofluoresence for malaria antigen should be applied for screening for malaria. VDRL test may be used to detect high risk donors rather than detection of syphilis when stored blood is used. HBsAg and HIV tests should be routinely done on every unit of blood and anti HCV tests should be done regularly, if possible.

In vivo evaluation of a hollow fiber liver assist device

Orthotopic liver transplantation is the only effective form of therapy currently available for patients with fulminant hepatic failure (FHF). The use of an extracorporeal (EC) liver assist device (LAD) may result in improved presurgical clinical management. Alternatively, patients treated with LADs could avoid the transplantation procedure if they are able to regenerate a critical mass of hepatocytes that will sustain functional viability. In this study, the efficacy of a prototype hollow fiber LAD seeded with rabbit hepatocytes was assessed in vivo by the use of two different animal models: (1) normal rabbits injected with diazepam or lidocaine, and (2) a galactosamine (Gal)-intoxicated rabbit model of FHF. The EC LAD clearly decreased the blood levels of the two drugs and significantly generated diazepam and lidocaine metabolites indicating the maintenance of active P450 forms in the cellular component of the devices. A 6-hour EC treatment significantly increased the survival time and delayed the onset of hepatic encephalopathy (HE) in the Gal-intoxicated rabbits. Histological evaluations of postmortem livers showed greater hepatocyte regenerative activity in the animals treated with hepatocyte-seeded LADs than in the two control groups, e.g., rabbits not treated or treated with unseeded devices. These findings support the concept that a microporous hollow fiber LAD seeded with rabbit hepatocytes is able to sustain drug detoxification in vivo as well as to modify the course of FHF in a well-characterized animal model.

Compound heterozygosity of HLA-DR4 and DR1 antigens in Asian Indians increases the risk of extra-articular features in rheumatoid arthritis

The relationship of HLA-DR antigens in rheumatoid arthritis (RA) patients with the presence of rheumatoid factor (RF), extra-articular features, joint erosions, functional status and response to disease modifying anti-rheumatic drugs (DMARDs) was studied. Seventy-four patients with RA were serologically typed for class II antigens. Clinical features were recorded before starting DMARDs and during follow-up to assess response and side-effects. HLA-DR1 and DR4 antigens were present more frequently in patients with RA than in the general population. The presence of DR4 correlated with RF seropositivity (P < 0.001) while DR1 was associated with seronegativity (P < 0.02). Ten of the 11 patients with extra-articular features had DR1 and/or DR4. Patients with both DR4 and DR1 had a significantly higher frequency of extra-articular features compared with those with only one of these (P < 0.01). HLA-DR4 and DR1 had no relation with the presence of subcutaneous nodules, erosive changes, deformities, response to drugs and side-effects of DMARDs.

High prevalence of HBV infectivity in blood donors detected by the dot blot hybridisation assay

Hepatitis B virus (HBV) continues to be a significant cause for post-transfusion hepatitis in India, in spite of the introduction of compulsory hepatitis B surface antigen (HBsAg) screening. To understand the true HBV-infective pool in the blood donor population, HBV DNA was detected by a 32P-labelled dot blot hybridisation assay in 605 donor units that were negative for HBsAg by a third-generation Elisa. Serum alanine aminotransferase (ALT) was estimated in all these samples and correlated with DNA positivity. The frequency of HBV DNA positivity in HBsAg-negative units was very high (9.91%) and correlated well with the elevation in ALT (p < 0.00005). However, the frequency of elevated ALT was high (11.9%), using the locally determined upper limit of normal, and half of the DNA-positive samples had a normal ALT. Thus, ALT is a poor surrogate marker for HBV infectivity and efforts should be made to apply DNA detection systems in blood banks.

Immunomodulation by interleukin-2 receptor targeted therapy

The interleukin-2 receptor (IL-2R) is expressed on proliferating T-lymphocytes following antigen stimulation. Activated IL-2R bearing lymphocytes accumulate as cellular infiltrates in autoimmune thyroiditis, insulin-dependent diabetes mellitus, rheumatoid arthritis and graft rejection. Affected cells in Hodgkin's disease, hairy cell leukaemia, non-Hodgkin's lymphoma, cutaneous T-cell lymphoma and lymphoid blast crises of chronic myeloid leukaemia also express IL-2R. Anti-IL-2R monoclonal antibodies or chimeric IL-2R toxins provide a way of selective elimination of such cells. These have been used in experimental models of autoimmunity and transplantation with beneficial results, providing a novel way of selective immunosuppression. In open uncontrolled trials, chimeric IL-2R toxin was found to be safe and effective in patients with refractory rheumatoid arthritis, insulin-dependent diabetes mellitus and IL-2R bearing leukaemias and lymphomas.

Serum IgM rheumatoid factor by enzyme-linked immunosorbent assay (ELISA) delineates a subset of patients with deforming joint disease in seronegative juvenile rheumatoid arthritis

Using human IgG as an antigen in an enzyme-linked immunosorbent assay (ELISA), we looked for the presence of IgM rheumatoid factor (RF) in the sera of 74 children with juvenile rheumatoid arthritis (JRA). Nine children had RF detectable by both latex agglutination and ELISA. Forty-five percent (26 of 65) of the children who were seronegative by latex agglutination were found to be positive for IgM RF by ELISA. The prevalence of IgM RF was higher in patients with polyarticular onset disease (57.4%) than in those with pauciarticular onset (38.5%) or systemic onset (27.2%) disease. The prevalence of RF was higher in sera from patients with deforming joint disease than those without deformities (P < 0.01).

Primary cultures of rat hepatocytes in hollow fiber chambers

Hepatocyte culture may represent an alternative to the use of animals to study drug detoxification by the liver. An ideal in vitro system should closely mimic the in vivo environment by providing continuous media perfusion and oxygenation, and should facilitate sampling of cells and culture media. To meet these criteria, a hollow fiber bioreactor seeded with isolated rat hepatocytes was developed and tested by measuring the formation of three products of the oxidative metabolism of diazepam and the glucuronidation of phenolsulfonphthalein (PSP). To compare the performance of conventional monolayer culture to that of the bioreactor system, diazepam metabolism was studied for 45 days in both systems. The oxygen dependency of diazepam metabolism was evaluated by perfusing the bioreactor in an oxygen-rich atmosphere (30%). Total diazepam metabolism was twofold higher in the O2-rich perfused hollow fiber cultures than in the cultures perfused under normal conditions, reflecting an increase in temazepam and oxazepam production. Diazepam detoxification activity was significantly enhanced by oxygen (P < or = 0.001) over the life of the perfused cultures. PSP metabolism was similar in all three culture systems. By Day 10, diazepam metabolism in the oxygenated bioreactor system was 44% of the in vivo activity of rat hepatocytes. This activity dropped to 30% by Day 25 of culture. These results justify the use of perfused culture systems for in vitro detoxification studies as an alternative to animal use and emphasize the capacity of a culture device perfused under O2-enriched conditions to maintain long-term P450 activity of rat hepatocytes.

Multiple protein-binding domains and functional cis-elements in the 5'-flanking region of the human pyruvate dehydrogenase alpha-subunit gene

We have characterized the 5'-flanking region of the alpha-subunit gene of the human pyruvate dehydrogenase (E1). DNase I footprinting with rat liver nuclear extracts identified 7 major protein-binding domains termed P1 through P7 in a 796 base pair DNA fragment (base pairs -763 to +33). P1 through P4 are clustered in the -221/+33 region. These protein-binding domains contain several known consensus sequences such as a TATA box, CAAT box, Sp1, and CRE, which all have previously been implicated in the constitutive transcription of several genes. Oligonucleotide competition studies indicate that oligonucleotides specific for CTF/NF-1 and Sp1 displaced the nuclear proteins bound to the CAAT box (within P3) and an Sp1 site (within P4), respectively. Several other well-characterized and purified transactivators (c-Fos, c-Jun, C/EBP, AP-2, and Sp1) have been shown to bind to the -221/+33 region. Other elements located upstream of the -221/+33 region, which includes nuclease protection domains P5-P7, are required for enhanced promoter activity of the 796 bp sequence. Promoter activity was measured by transient expression of a chloramphenicol acetyltransferase gene ligated to deletion fragments of the 5'-flanking region. Crucial element(s) for promoter activity and complex DNA-nuclear protein interactions were confined within a region spanning -221/+33. This region also retained more than 75% of the promoter activity of the 796 bp sequence. Additionally, this promoter region shows characteristics of both facultative and housekeeping gene promoters, suggesting complex transcriptional regulation.

Interleukin-8 release and neutrophil degranulation after pediatric cardiopulmonary bypass

Capillary leak after cardiopulmonary bypass operations for correction of congenital heart defects is universally seen in children and often causes significant morbidity and mortality. Since neutrophil-mediated endothelial injury has been implicated as a pathogenetic mechanism, a prospective controlled descriptive study was performed to investigate possible activation pathways during and after the bypass procedure. Eighteen children undergoing operations, nine with cardiopulmonary bypass and nine neurosurgical craniotomy (i.e., operations without bypass), had samples of arterial blood collected at intervals before, during, and after operations. In six of nine cardiac patients circulating interleukin-8 concentrations rose from less than 30 pg/ml to very high concentrations (> 500 pg/ml); in the remaining three patients small rises (peak 57 to 81 pg/ml) were also seen. In all nine, the rise commenced at the time of rewarming, toward the end of bypass, and peaked 1 to 3 hours thereafter. Interleukin-8 release correlated significantly with length of bypass. Interleukin-1 alpha and interleukin-1 beta were not found, and traces of tumor necrosis factor-alpha were detected in one patient only. Circulating elastase alpha 1-antitrypsin concentrations rose simultaneously and correlated significantly with interleukin-8 (p < 0.001) in patients with cardiac disease, as did absolute neutrophil counts (p < 0.001). In contrast, only one of nine patients with neurosurgical disease (undergoing an unusually long operation and exchange transfusion) had a rise in circulating interleukin-8 to levels greater than 500 pg/ml (p < 0.01). The two samples from this patient with elevated interleukin-8 were the only neurosurgical samples with elevated elastase. This study demonstrates the release of interleukin-8 into the circulation after pediatric hypothermic cardiopulmonary bypass and supports the suggestion that this cytokine plays a role in the pathophysiology of capillary leak through neutrophil degranulation.

Audit in the management of gliomas

A retrospective study of 139 glioma patients was conducted in an effort to audit management. Factors affecting survival were studied using a Cox Proportional Hazard Model. These factors included age, sex, location, grade, type of surgery, use of radiotherapy, presenting symptoms, Karnofsky score on admission and Karnofsky score 3 months following surgery. Lower grade, high Karnofsky score on admission, radiotherapy and frontal location were associated with better survival. There was statistically insignificant evidence that the other factors had an influence on survival. Patients presenting with a poor neurological score were treated with burrhole biopsy alone. Only 10% of these patients survived more than 6 months. On the other hand, 26% of patients who had craniotomy on the basis of reasonable clinical status lived less than 6 months. Sixty-six per cent of patients in this craniotomy group were aged 60 years or over, and 66% of those aged over 60 had a Karnofsky score of less than 70. We conclude that careful judgement is required before subjecting patients aged over 60, especially those with a low Karnofsky score, to radical therapy.

Scleromyxoedema with features of systemic sclerosis

The case is described of a patient with scleromyxoedema with features typical of systemic sclerosis. The features were so characteristic that the disease was misdiagnosed as systemic sclerosis. A brief review of the association of the two diseases is given.

Prevalence of antibodies to hepatitis C virus in HBsAg negative hemodialysis patients

The prevalence of hepatitis C virus (HCV) infection was estimated in a 14-month study using anti-C100-3 antibody assay in 31 HBsAg negative patients on maintenance hemodialysis (MHD) for > or = 3 months. One and three patients respectively had ALT elevation and anti-HCV positivity at entry. During MHD (mean period of follow up 9.9 mo), 11 (35.5%) patients had, on fortnightly estimation, ALT elevation which lasted for < or = 6 months in seven patients and for > 6 months in four. Fourteen (45.2%) patients had anti-HCV (including the three positive at entry). There was no significant difference in frequency of anti-HCV positivity in patients with normal and elevated ALT (57.1% and 42.9% respectively). The number of blood transfusions and duration of MHD were similar in anti-HCV positive and anti-HCV negative patients. We conclude that our MHD patients have a high frequency of hepatitis and anti-HCV positivity, and these may not be related to blood transfusions.

Explosive Campylobacter jejuni diarrhea in immunoproliferative small intestinal disease

Campylobacter jejuni is an infrequent cause of self limiting acute diarrheal disease in adults in the Indian subcontinent. We report the occurrence of a life threatening diarrhea due to C jejuni infection in a patient with immunoproliferative small intestinal disease. We postulate that immunosuppression due to malignancy, malnutrition and cancer chemotherapy was responsible for the unusually severe diarrhea.

Filter paper blood spot test for detection of anti-ND-BSA antibodies in school children

For identifying individuals at 'high risk' for developing leprosy, a simplified technique of collection of blood samples on filter paper for detection of anti -ND-BSA antibodies, was optimised. Anti-ND-BSA antibody reactivity on the filter paper was lost on storage at room temperature, but was stable at least for a period of 8 wk at lower temperature. Among the 1495 children screened, 166 (11.1%) were lepromin negative and 122 (8.2%) positive for anti-ND-BSA antibody. In the first phase, 7 of 871 children followed up for 2 yr developed leprosy, while in the second phase 2 of 624 children followed-up for 9 yr developed leprosy. The positivity and negativity of anti-ND-BSA antibodies and lepromin in these I children indicate that the positive status for anti-ND-BSA antibodies has a better predictive value than negative lepromin reactivity. Measurement of anti-ND-BSA antibodies was also of value for monitoring the efficacy of therapy and course of the disease. Extrapolation of the two tests to the total population of children evaluated showed that an individual with negative lepromin reactivity along with presence of anti-ND-BSA antibodies is at a higher risk for developing leprosy than those who have both the tests normal. Lepromin reactivity alone was not of much value for the prediction for development of the disease. However, the presence of anti-ND-BSA antibody was a better indicator for the development of the disease. The probability of developing leprosy in a child with any one of the tests abnormal was higher as compared to a child having all the tests normal.

The use of placenta in a microvascular exercise

Twenty-five human placentas were studied for suitability in a microvascular exercise. The size and useful length of vessels were measured, and different microvascular anastomoses were performed. The size of the placenta vessels compared well with reported sizes of intracranial arteries. We suggest the use of placenta by neurosurgeons as complementary to experimental animals in microvascular training.

Is repeated coronary surgery for recurrent angina cost effective?

Between January 1980 and May 1988, 1363 patients underwent first time coronary artery bypass grafting (CABG) and 49 (3.6%) were reoperated for recurrent angina by the same surgeon in this unit. There were 42 males and five females with a mean age of 53.6 years. Mean time since first operation was 68.9 (37 SD) months. Prior to surgery only eight (16.3%) were still working. There were three hospital deaths and two late deaths at 2.5 and 3.5 years after surgery and one patient underwent cardiac transplantation at 1.5 years. Follow-up has been completed up to March 1989, mean 3.7 years, range 10-108 months. Questionnaires were sent to all patients concerning the financial and functional situation. Hospital expenses were calculated (a) prospectively for 15 consecutive first time CABGs and for five second time CABGs, (b) retrospectively from patients' records with the help of a simple computer programme. The final figures were corrected for inflation rates. The 1- and 5-year actuarial probability of angina-free interval was 87.5% and 40% respectively. Eight patients (12.2%) had no benefit, six (13.6%) had benefit but were not able to work, 16 (36.4%) were able to work but unemployed and 14 (13.8%) were fully employed producing a total salary of 69,072 pounds per annum. Hospital expenses were: first time CABG 3645-4049 pounds, second time CABG 6290-7235. The total for the entire group was 308 166 pounds. Repeated coronary surgery can be accomplished with reasonable mortality and has good late results.(ABSTRACT TRUNCATED AT 250 WORDS)

Phenobarbital induction of cytochromes P-450. High-level long-term responsiveness of primary rat hepatocyte cultures to drug induction, and glucocorticoid dependence of the phenobarbital response

The induction of hepatic cytochromes P-450 by phenobarbital (PB) was studied in rat hepatocytes cultured for up to 5 weeks on Vitrogen-coated plates in serum-free modified Chee's medium then exposed to PB (0.75 mM) for an additional 4 days. Immunoblotting analysis indicated that P-450 forms PB4 (IIB1) and PB5 (IIB2) were induced dramatically (greater than 50-fold increase), up to levels nearly as high as those achieved in PB-induced rat liver in vivo. The newly synthesized cytochrome P-450 was enzymically active, as shown by the major induction of the P-450 PB4-dependent steroid 16 beta-hydroxylase and pentoxyresorufin O-dealkylase activities in the PB-induced hepatocyte microsomes (up to 90-fold increase). PB induction of these P-450s was markedly enhanced by the presence of dexamethasone (50 nM-1 microM), which alone was not an affective inducing agent, and was inhibited by greater than 90% by 10% fetal bovine serum. The PB response was also inhibited (greater than 85%) by growth hormone (250 ng/ml), indicating that this hormone probably acts directly on the hepatocyte when it antagonizes the induction of P-450 PB4 in intact rats. In untreated hepatocytes, P-450 RLM2 (IIA2), P-450 3 (IIA1) and NADPH P-450 reductase levels were substantially maintained in the cultures for 10-20 days. The latter two enzymes were also inducible by PB to an extent (3-4 fold elevation) that is comparable with that observed in the liver in vivo. Moreover, P-450c (IA1) and P-450 3 (IIA1) were highly inducible by 3-methylcholanthrene (5 microM; 48 h exposure) even after 3 weeks in culture. In contrast, the male-specific pituitary-regulated P-450 form 2c (IIC11) was rapidly lost upon culturing the hepatocytes, suggesting that supplementation of appropriate hormonal factors may be necessary for its expression. The present hepatocyte culture system exhibits a responsiveness to drug inducers that is qualitatively and quantitatively comparable with that observed in vivo, and should prove valuable for more detailed investigations of the molecular and mechanistic basis of the response to PB and its modulation by endogenous hormones.