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Intrabiliary rupture of a hydatid liver cyst is infrequently reported, but may present with symptoms of choledocholethiasis or cholangitis. We report a case of hydatid liver disease presenting as recurrent pancreatitis, and discuss its clinical, radiological and surgical treatments. Hydatid liver disease has a diverse clinical spectrum, and a diagnosis of acute pancreatitis should be considered in patients with hydatid liver disease presenting with unexplained abdominal pain.

The aim of this study was to compare the ability of artificial neural networks and the Acute Physiology and Chronic Health Evaluation II score to predict mortality in adult intensive care units. The same physiological variables were used in both predictive models to predict hospital mortality from a data set of 8796 patients collected from 26 adult intensive care units in the United Kingdom and Ireland as part of the Intensive Care Society study. The results from the two models were compared with the actual outcome. The overall prediction accuracy and the overall goodness-of-fit of all the models were assessed. Both predictive models showed similar goodness-of-fit and prediction discrimination. The overall predictive and classification performance of the artificial neural network developed matched and in some aspects was better than that of Acute Physiology and Chronic Health Evaluation II.

Metastatic melanoma of the small bowel is a pathological entity that is not frequently reported but may present with features of unexplained anaemia. We report a case of a 51-year-old man with occult intestinal bleeding due to metastatic melanoma of the small bowel. Although the diagnosis was somewhat delayed, the patient was managed successfully by small bowel resection. Careful investigation of melanoma patients with gastrointestinal symptoms is important as surgical intervention often results in improved quality of life and survival.

The military and some civilian rescue agencies have a requirement for portable ventilators in the anaesthetic, resuscitation and pre-hospital environment. This paper describes two new portable ventilators specifically designed to satisfy the military requirement for lightweight, robust and versatile equipment which can also be used in a contaminated environment.

Hypothesis: Patients with melanoma and histologically negative sentinel lymph nodes identified by lymphatic mapping have a very good prognosis., Design: Cohort study with follow-up information obtained from medical records and telephone interviews., Setting and Patients: Of all patients with cutaneous melanoma who underwent intraoperative sentinel lymph node mapping between November 15, 1993, and April 18, 1997, at the Massachusetts General Hospital, Boston, 89 were found to have no evidence of melanoma in their sentinel nodes. Forty-six lesions (51%) were on an extremity and 44 (49%) were of axial location. The median tumor thickness was 1.8 mm (range, 0.36-12.0 mm) and 11 tumors (12%) were ulcerated., Interventions: Patients underwent intraoperative sentinel lymph node mapping with lymphazurin and radiolabeled sulfur colloid. Sentinel lymph nodes were analyzed by standard hematoxylin-eosin staining. Only 2 patients received adjuvant therapy following wide excision of the primary lesion., Main Outcome Measures: Site of initial recurrence and time to initial recurrence., Results: The median follow-up for all patients was 23 months (range, 2-54 months). Eleven patients (12%) developed melanoma recurrences, and 78 (88%) patients remain disease free. Regional lymph nodes were the initial site of recurrence in 7 (8%) of 89 patients, and 7 (7%) of 106 mapped basins. Four patients had recurrence without involvement of regional lymph nodes: 2 with distant metastases and 2 with in transit metastases. The median time to recurrence was 12 months (range, 2-35 months). Sentinel lymph nodes were reanalyzed using serial sections and immunoperoxidase stains in 7 patients with recurrence and metastatic melanoma was identified in 3 (43%)., Conclusions: The risk for melanoma recurrence is relatively low in patients with histologically negative sentinel nodes identified by lymphatic mapping. Longer follow-up will improve our understanding of the prognostic value of this procedure.

We report a case of metastasis from a regressed cutaneous melanoma presenting as an acute abdomen. The patient presented with peritonitis, which at operation was found to be due to intraperitoneal haemorrhage from a bleeding metastatic melanoma lesion in the ileum. Surgical resection was performed and the patient remained well 2 years later.

Several endogenous oscillators determine circadian rhythms. One, light-entrained, is in the suprachiasmatic nuclei (SCN), the others, food-entrained, are in unknown sites. To determine how the hypothalamic ventromedial nuclei (VMN) and feeding affect rhythms, we compared nocturnally active rats fed either ad libitum or for 2 hr/d during light [restricted feeding (RF)] and either with or without colchicine-induced disruption of VMN. We measured rhythms in temperature, locomotor activity, feeding, drinking, corticosterone, and the numbers of cells expressing c-Fos in light/dark in hypothalamic nuclei, the suprachiasmatic nuclei, and two major SCN targets, the subparaventricular zone (sPVNz) and paraventricular thalamus (pvTHAL). c-Fos cells were always light > dark in SCN, whereas the VMN and sPVNz lacked light/dark differences except after RF and RF plus VMN disruption, respectively. Controls fed ad libitum had high-amplitude rhythms and, generally, c-Fos cells dark > light. In RF controls, a c-Fos pattern dark > light occurred in VMN; generally, c-Fos cell numbers increased elsewhere maintaining dark > light. By contrast, levels of corticosterone peaked before food. In rats fed ad libitum, VMN with colchicine markedly reduced rhythm amplitudes, not phase. c-Fos patterns were abolished except in pvTHAL and SCN. In RF, VMN disruption blocked corticosterone and light/dark c-Fos patterns in all nuclei but produced a pattern in the sPVNz like SCN. We conclude that VMN amplify rhythmic output from the SCN, and the RF-induced rhythm in VMN enhances c-Fos activity driven by the SCN. The VMN may contain a food-entrained oscillator, and the sPVNz may integrate output from several oscillators.

Background: In the search for occult metastases in lymph nodes or circulating tumour cells, a reverse transcriptase-polymerase chain reaction (RT-PCR) assay was developed to detect tumour-specific splice variants of the transcript of the CD44 gene. The assay was highly sensitive and could detect ten tumour cell per 10(5) leucocytes., Methods: RNA was purified from peripheral blood (n = 24) and regional lymph nodes (n = 14) from patients with colorectal cancer. Complementary DNA was made and amplified using primers specific for the CD44 gene. Southern blotting with exon-specific probes was used to enhance the sensitivity., Results: Tumour cells were detected in peripheral blood samples in four patients and lymph nodes in nine, in one of whom conventional histology had not detected tumour cells., Conclusion: This technique may be useful in the early diagnosis of primary or metastatic tumours, in assessing prognosis and in detecting residual disease after treatment.

Background: The CD44 gene codes for a family of heavily glycosylated cell surface proteins that have been linked with tumour metastasis. The aim of the study was to analyse the expression of CD44 messenger RNA in colorectal cancer., Methods: The expression of CD44 variants 2 and 7 in colorectal tumour samples was compared with that in normal colon and lymphocytes from 59 patients using reverse transcription-polymerase chain reaction followed by blot hybridization with exon-specific probes, and a nested polymerase chain reaction., Results: All samples of tumour and metastatic tissue showed complex overexpression of many alternatively spliced products of the CD44 gene. Normal colon, liver and lymphocytes predominantly expressed the standard form of the CD44 molecule (CD44S) with low levels of two or three variants hybridizing to exons v2 and v7., Conclusion: Deranged CD44 gene activity in colorectal cancer cells is confirmed. The analysis of CD44 gene expression may provide a promising marker for the early detection of colonic tumours.

When a spa bath was installed in the maternity unit of Osborne Park Hospital, a Quality Assurance survey was undertaken to try to identify any potential problems. At the same time a client satisfaction survey was conducted. The study highlighted many benefits to the client as an alternative method of pain management. At the same time no obvious problems were identified. However, due to lack of control of the many variables, and the absence of statistical analysis, no definite conclusions can be drawn from the study. Positive responses from clients encourage us to continue to offer the spa bath as a method of pain management. This is an area which begs research.

The effects of nitrous oxide on left ventricular diastolic function and its potential interactions with ischemia-induced diastolic dysfunction have not been described. Accordingly, we investigated the effects of nitrous oxide in ischemic and remote nonischemic myocardium during baseline, 90 min severe low-flow myocardial ischemia (systolic bulge), and reperfusion in 11 open-chest dogs. Anesthesia was maintained with fentanyl infusion (2 micrograms.kg-1.min-1), animals were ventilated with 60% nitrogen in oxygen, and hemodynamic variables were recorded prior to and after the replacement of nitrogen by 60% nitrous oxide. During baseline, nitrous oxide moderately increased chamber stiffness (+ 10%), myocardial stiffness (+33%), and unstressed length (+4%) and decreased the peak lengthening rate (-10%). Moreover, nitrous oxide decreased regional contractility during baseline (-12% at apex, -8% at base) as well as in nonischemic myocardium during myocardial ischemia (-9%) and reperfusion (-8%). However, nitrous oxide did not modify ischemia-induced systolic or diastolic dysfunction in ischemic myocardium during ischemia and reperfusion. Myocardial ischemia (+45%) and reperfusion (+57%) were associated with an increase in myocardial stiffness of nonischemic myocardium regardless of the anesthetic technique used. This study is the first to demonstrate that in addition to its well established negative inotropic effect, nitrous oxide affects regional diastolic function.

The presence of free malignant cells in the peritoneal cavity following potentially curative resection of colorectal cancer may be responsible for some cases of local recurrence. Twenty-six patients (age 58-88 years, male:female 12:14) undergoing colorectal cancer surgery were studied to determine frequency of occurrence of tumour cells in the peritoneal cavity using an immuno-magnetic cell separation technique. Peritoneal washings were collected after opening the peritoneal cavity and also prior to closure. A murine monoclonal antibody specific for epithelial cells was added to the peritoneal washings followed by magnetic labelled goat-antimouse antibody. The labelled tumour cells were retrieved by passing through the magnetic activated cell sorter (MACS). Tumour cells were detected in peritoneal washings from 11 patients (preresection only n = 0, post-resection only n = 6, and both n = 5). Five of these 11 patients had potentially curative surgery. This study supports the use of MACS in detecting free malignant cells in the peritoneal cavity.

A technique has been developed for the detection of tumour cells in blood with the magnetic activated cell sorter (MACS). Colonic carcinoma cell lines and disaggregated primary tumours were used to establish optimal conditions of separation. A murine monoclonal antibody specific for epithelial cells was added to the suspension of leucocytes and tumour cells, followed by magnetic labelled goat antimouse antibody. The labelled tumour cells were retrieved by passing this suspension through a MACS separation column in a strong magnetic field. Tumour cells were detected at a dilution of 10 cells per ml blood. Tumour cells were identified in mesenteric blood in three of 24 patients undergoing surgery for colorectal cancer. This study supports the use of the MACS to detect circulating tumour cells.

Aggressive angiomyxoma (AAM) is a rare, locally infiltrative but nonmetastasizing tumor of the pelvic and perineal soft tissues that occurs almost exclusively in adult females. The authors describe four cases of AAM in adult males that arose in the scrotum. There was some histologic variation among the tumors. One case was focally hypercellular around the blood vessels, two were more densely cellular throughout, and one had cystic degeneration. Three of the tumors were widely infiltrative, and one of the four tumors recurred locally. The clinicopathologic features of these cases are similar to those of AAM occurring in females. In either sex, AAM should be distinguished from benign myxoid tumors with a low risk of local recurrence and fully malignant myxoid tumors with distant metastatic potential.

We observed a large efflux of nonvolatile radioactivity from Bacillus subtilis in response to the addition of 31 mM butyrate or the withdrawal of 0.1 M aspartate in a flow assay. The major nonvolatile components effluxed were methionine, proline, histidine, and lysine. In studies of the release of volatile radioactivity in chemotaxis by B. subtilis cells that had been labeled with [3H]methionine, the breakdown of methionine to methanethiol can contribute substantially to the volatile radioactivity in fractions following addition of 0.1 M aspartate. However, methanol was confirmed to be released after aspartate addition and, in lesser quantities, after aspartate withdrawal. Methanol and methanethiol were positively identified by derivitization with 3,5-dinitro-benzoylchloride. Amino acid efflux but not methanol release was observed in response to 0.1 M aspartate stimulation of a cheR mutant of B. subtilis that lacks the chemotaxis methylesterase. The amino acid efflux could be reproduced by withdrawal of 0.1 M NaCl, 0.2 M sucrose, or 0.2 M xylitol and is probably the result of changes in osmolarity. Chemotaxis to 10 mM alanine or 10 mM proline resulted in methanol release but not efflux of amino acids. In behavioral studies, B. subtilis tumbled for 16 to 18 s in response to a 200 mosM upshift and for 14 s after a 20 mosM downshift in osmolarity when the bacteria were in perfusion buffer (40 mosM). The pattern of methanol release was similar to that observed in chemotaxis. This is consistent with osmotaxis in B. subtilis away from an increase or decrease in the osmolarity of the incubation medium. The release of methanol suggests that osmotaxis is correlated with methylation of a methyl-accepting chemotaxis protein.

Significant numbers of infiltrating mononuclear cells are commonly observed in solid tumours, although their role in restricting tumour growth is not clear. Tumour-infiltrating lymphocytes (TIL) from 38 patients with colorectal cancer, in parallel with peripheral blood lymphocytes (PBL), were assayed to determine their ability to proliferate in response to concanavalin A (ConA), interleukin-2 (IL-2), ConA+IL-2, phorbol 12-myristate 13-acetate (PMA)+ionomycin ionomycin (IOM), and staphylococcal enterotoxin B(SEB). These reagents were selected to give a range of weak to strong proliferative responses either via or independent of the T cell receptor. Proliferation of TIL was significantly lower than that of PBL in all cultures: ConA (P < 0.001), IL-2 (P = 0.002), ConA+IL-2 (P < 0.001), PMA+IOM (P < 0.001), SEB (P = 0.002). In addition to the low proliferative capacity of TIL, production of cytokines by TIL may also play a role in control of tumour growth. We have assayed IFN gamma production in the supernatants from 16 paired TIL and PBL cultures, and tumour necrosis factor alpha (TNF alpha) in 6 paired cultures. TNF alpha concentrations were significantly lower in TIL cultures than in PBL cultures stimulated with ConA (P < 0.05), but no different in control or IL-2 stimulated cultures. IFN gamma levels did not significantly differ between PBL and TIL cultures, indicating that despite the restricted proliferative capacity of TIL, these cells remain capable of secreting significant amounts of IFN gamma.

Taxis to oxygen (aerotaxis) in Bacillus subtilis was characterized in a capillary assay and in a temporal assay in which the concentration of oxygen in a flow chamber was changed abruptly. A strong aerophilic response was present, but there was no aerophobic response to high concentrations of oxygen. Adaptation to a step increase in oxygen concentration was impaired when B. subtilis cells were depleted of methionine to prevent methylation of the methyl-accepting chemotaxis proteins. There was a transient increase in methanol release when wild-type B. subtilis, but not a cheR mutant that was deficient in methyltransferase activity, was stimulated by a step increase or a step decrease in oxygen concentration. The methanol released was quantitatively correlated with demethylation of methyl-accepting chemotaxis proteins. This indicated that methylation is involved in aerotaxis in B. subtilis in contrast to aerotaxis in Escherichia coli and Salmonella typhimurium, which is methylation independent.

Post-systolic shortening is a wall motion abnormality defined as shortening of cardiac muscle after the end of ejection and usually regarded as a manifestation of ischaemia. This study was designed to determine whether changes in preload may alter the magnitude of ischaemia-induced post-systolic shortening. Eleven beagles were anaesthetized (halothane 0.8%) and instrumented for measurement of pressures, flows and dimensions in the apical subendocardium supplied by the left anterior descending coronary artery. Myocardial ischaemia was obtained by tightening a micrometer-controlled snare around the left anterior descending coronary artery. Post-systolic shortening, calculated as end-systolic length minus minimum length divided by end-systolic length, was measured at different levels of preload. Increasing the preload from 4 to 17 mmHg caused a significant reduction in post-systolic shortening (8.9% vs. 12.9%, P < 0.05, Student's paired t-test); post-systolic shortening was negatively correlated with coronary perfusion pressure (r = 0.35, P < 0.01) and positively correlated with systolic bulging. This study demonstrates that the amount of post-systolic shortening depends on the volume status, which therefore has to be taken into account in interpreting regional wall motion abnormalities, such as those detected by echocardiography.

Though a sustained post-ischemic decrease in contractile function has been clearly established, post-ischemic diastolic function has not been thoroughly investigated. Accordingly, 11 anesthetized (isoflurane 1%) open-chest beagles were instrumented to measure left ventricular pressure and dimensions (circumferential length and wall thickness) in an apicoanterior area supplied by the left anterior descending coronary artery (LAD). Pressure-dimension relations were modified by stepwise infusion and withdrawal of 200 mL of the animals' own blood during baseline, 45 minutes partial occlusion of the LAD (systolic bulging), and 60 minutes after the onset of reperfusion. Stiffness constants were derived from the end-diastolic pressure-length and stress-strain relations, respectively. Myocardial ischemia was associated with significant (P < 0.05) alterations of the following parameters of diastolic function: (1) 47% increase in end-diastolic pressure; (2) 22% decrease in peak negative dP/dt; (3) 9% increase in the time constant of isovolumic relaxation (tau); (4) postcystolic contraction; (5) 6% increase in end-diastolic length and 10% decrease in end-diastolic thickness; (6) 12% increase in unstressed length (creep) and 13% decrease in unstressed thickness; (7) 51% increase in chamber stiffness and a 63% increase in myocardial stiffness; and (8) 40% decrease in the peak lengthening rate. After 60 minutes of reperfusion, only end-diastolic pressure and tau had returned to baseline values whereas systolic shortening fraction, postsystolic contraction, and end-diastolic and unstressed dimensions had only partially recovered. No recovery occurred in peak negative dP/dt, chamber stiffness, myocardial stiffness, and peak lengthening rate. Thus, both myocardial ischemia and reperfusion are associated with complex changes in global and regional left ventricular diastolic function.

Objectives: This study was designed to investigate the changes in regional distensibility of the ischemic segment and of a remote nonischemic segment brought about by graded myocardial ischemia., Background: Ventricular distensibility is a major determinant of left ventricular end-diastolic pressure. The effects of graded myocardial ischemia on the regional distensibility of the ischemic area have not been studied. Moreover, there are few data on the effects of myocardial ischemia on the regional distensibility of the nonischemic myocardium., Methods: Nine anesthetized open chest mongrel dogs were fitted with instruments to measure left ventricular pressure and circumferential length (sonomicrometry) in the ischemic segment and in a nonischemic segment. The pressure-length relation was modified by stepwise infusion and withdrawal of 200 ml of each dog's own blood over 30 min in five consecutive stages of regional ischemia. Unstressed dimensions were obtained by repeated inferior vena cava occlusions. In both segments, regional distensibility was assessed at end-diastole by means of the constants of the pressure-length (chamber stiffness), the pressure-strain and the force-strain (myocardial stiffness) relations., Results: In the ischemic segment, partial and complete coronary occlusions were associated with a twofold increase in the chamber stiffness constant, the pressure-strain constant and the myocardial stiffness constant, whereas in the nonischemic segment the chamber stiffness constant, the pressure-strain constant and the myocardial stiffness constant increased by 50%., Conclusions: Regional myocardial ischemia is associated with a decrease in distensibility of both the ischemic and the remote nonischemic myocardium.

To investigate the possibility of regional differences in cardiac stiffness which may relate to the known regional differences in systolic left ventricular function, seven mongrel dogs were acutely instrumented and regional cardiac stiffness was measured at both apical and basal region under two different concentrations of isoflurane (1.08% and 1.9%) as well as equipotent concentrations of halothane (0.9% and 1.58%). Cardiac stiffness was determined in terms of distensibility, chamber stiffness (derived from pressure-length relationships), and an elastic stiffness constant (derived from stress-strain relationships). Regional differences in cardiac stiffness were observed for all three indices and for each anaesthetic setting except for the elastic stiffness constant under 1.9% of isoflurane. The data indicate that regional differences in cardiac stiffness exist between the apex and the base of the heart. These regional differences do not depend on the anaesthetic agent or its concentration and may contribute to the differences in systolic function.

The aim of the present study was to separate and characterise products formed by oxidation of uric acid by hydroxyl radicals with a view to probing for these products in vivo in clinical contexts. Aerated solutions of 200 microM uric acid, or its oxidation products, allantoin or parabanic acid, were exposed to gamma radiolysis, (52.0 Gy/min), as a source of HO. radicals, at pH 3.4 and 7.4. Aliquots were taken every 5 minutes for 20 minutes and oxidation products were separated by HPLC and analysed with a diode array detector. Identities of oxidation products were confirmed on the basis of similarity of retention times and absorbance spectra and peak purity parameters of known standards. Hydroperoxides were measured by tri-iodide formation in the 20 minute sample. Exposure of uric acid to such HO.fluxes produced a net loss of the parent compound with formation of a complex mixture of products with allantoin and parabanic acid being the predominant products at pH 3.4. The rate of uric acid degradation at physiological pH was slower and the distribution of oxidation products was different. A small but significant amount of uric acid hydroperoxide was detected at both pHs. A mechanism for uric acid oxidation under these conditions is presented.

In a randomized, controlled trial of recombinant interferon alfa-2b with or without prednisone priming in Chinese adults with chronic hepatitis B virus infection, stratified randomization for pretreatment serum alanine aminotransferase levels was done. Partial or complete antiviral responses were achieved in 17 (21.5%) of 79 treated patients and 3 (8.3%) of 36 controls (P = 0.14). The response to interferon treatment was significantly better in those who had elevated pretreatment transaminase levels and comparable to that reported in white patients [15 (38.5%) of 39 patients compared with 2 (5%) of 40 who had normal pretreatment transaminase levels (P = 0.0005)]. The spontaneous seroconversion rate was also higher among the controls with elevated transaminase levels [3 (18.8%) of 16 compared with 0 of 20 with normal transaminase levels], but this difference was not statistically significant (P = 0.16). Among the interferon-treated patients, prednisone priming appeared to have a marginal benefit over treatment with interferon alone in patients with elevated transaminase levels (43% vs. 33%), but not in those with normal transaminase levels (0% vs. 9.5%). It was confirmed that Chinese patients with normal transaminase levels respond very poorly to interferon alfa therapy. However, the response was significantly better in patients with elevated transaminase levels.

Propylthiouracil (PTU) has been demonstrated to reduce alcohol-induced hepatocyte damage and severe alcoholic liver disease. Although the mechanism by which the drug operates is yet to be elucidated, there is evidence that PTU may act as an antioxidant. The present study examines the reaction of PTU with oxygen free radicals and the ability of PTU to directly inhibit peroxidation of a model membrane system. PTU reacted directly with hydroxyl radicals produced by gamma-radiolysis. The rate constant for the PTU/hydroxyl radical reaction as determined by steady state competition kinetics with p-nitrosodimethylaniline was 8 x 10(9) L/mol/sec. PTU was less reactive towards superoxide generated by the xanthine/xanthine oxidase system, having a small but significant inhibitory effect on superoxide-induced reduction of cytochrome c only at a concentration of 200 microM. The ability of PTU to protect lipids from peroxidative changes was tested in membranes prepared from linoleic acid. The rate of peroxidation induced by 40 degrees heat decreased from 0.078 to 0.024 mM hydroperoxide/hr in the presence of 0-50 microM PTU. However, this trend was reversed at PTU concentrations above 50 microM. These data suggest that the protective effects of PTU against liver damage may be due to scavenging reactions with hydroxyl radicals in particular and/or its antioxidant potential.

This study aimed to determine the effect of streptozotocin (STZ)-induced diabetes on pulsatile LH secretion in the mature male rat. LH pulse frequency was reduced by 56% and pulse amplitude by 54%, with a consequential decrease of 72% in mean LH levels 8 days after i.v. administration of STZ (55 mg/kg) to castrated Wistar rats compared with castrated non-diabetic controls. Twice daily insulin treatment completely reversed all parameters of pulsatile LH secretion to control values. Food-restricted non-diabetic controls, studied to distinguish the metabolic effect of diabetes from that of concurrent weight loss, demonstrated a 34% reduction in LH pulse frequency but no significant changes in LH pulse amplitude or mean LH levels compared with non-diabetic controls given free access to food. To distinguish whether the decreased LH pulse amplitude in diabetes was due to a reduction in either the quantity of hypothalamic gonadotrophin-releasing hormone (GnRH) released per secretory episode or to decreased pituitary responsiveness to GnRH, the responsiveness of the pituitary to exogenous GnRH (1-1000 ng/kg body weight) was tested in diabetic rats after castration, using a full Latin square experimental design. The net LH response (total area under response curve over 40 min following GnRH) was decreased by 33% (P = 0.001) in diabetic compared with control rats. The decreased LH pulse frequency in STZ-induced diabetes therefore suggests that the metabolic effect of diabetes is to decelerate directly the firing rate of the hypothalamic GnRH pulse generator independent of testicular feedback. These effects were fully reversed by insulin treatment and were only partly due to the associated weight loss.(ABSTRACT TRUNCATED AT 250 WORDS)

The current seroepidemiology of hepatitis A in Hong Kong was examined by testing stored sera from 702 healthy subjects, collected between 1987-1989, for antibody to hepatitis A virus (anti-HAV). The overall prevalence of anti-HAV antibody was 45.6%. There were significant increases in prevalence of anti-HAV antibody with every 10-year increase in age up to age 40. The prevalence of anti-HAV antibody was 24% for subjects below age 30 and 89.2% for those above age 30 (P less than 0.0001). Socioeconomic factors did not appear to have any influence on the prevalence of anti-HAV antibody. In comparison with another study conducted in Hong Kong 10 years ago, the prevalence of anti-HAV antibody in the current study was significantly lower in every age group from 0 to 30 years. In summary, it was shown that HAV infection is no longer highly endemic in Hong Kong. In view of the changing epidemiology, postexposure prophylaxis will be necessary for young adults and children, and hepatitis A vaccine may be indicated for high risk groups when it is generally available.

Three-hundred forty-one HBsAg-positive family members of 152 patients with chronic hepatitis B virus infection (47 asymptomatic carriers, 59 with chronic hepatitis, 17 with cirrhosis and 29 with hepatocellular carcinoma) were prospectively studied to determine the morbidity and mortality from chronic hepatitis B virus infection in the family members of patients with malignant and nonmalignant hepatitis B virus-related chronic liver diseases. Most of the family members had no history of acute hepatitis, were asymptomatic and were unaware of their carrier status. However, 5.3% had stigmata of chronic liver disease, 6% had serum ALT levels that exceeded two times the upper limit of normal and 78% of those who had biopsies had chronic hepatitis with or without cirrhosis. During a follow-up period of 12 to 90 mo (median = 39 mo), 3% had symptoms of chronic liver disease; 24% had transient, recurrent or persistent elevation in serum ALT levels, 1.4% had cirrhosis and 1% had hepatocellular carcinoma. Neither hepatocellular carcinoma in the index patient nor a previous history of hepatocellular carcinoma in the family was associated with an increase in the morbidity and mortality from chronic hepatitis B virus infection in the HBsAg-positive family members.

The application of 1.2 and 12.0 micrograms/side of the GABAA receptor agonist 3-aminopropane sulphonic acid bilaterally into the nucleus accumbens (Acb) of rats nonsignificantly depressed locomotor activity as assessed in automated Animex activity cages, while the highest dose (60 micrograms/side) significantly stimulated activity. The GABAA receptor antagonists picrotoxinin (0.0625 and 0.125 micrograms/saide) and bicuculline (0.895 micrograms/side) produced forward locomotion around the cage accompanied by a number of other behaviours. The GABAB agonist baclofen (0.023 and 0.092 micrograms/side) induced a short-lasting (18 min) locomotor depression. None of the GABAB antagonists tested (2-hydroxysaclofen 2.6 micrograms/side, two novel beta-(benzo[b]furan) analogues of baclofen 9G or 9H each 6.8 micrograms/side, 4-aminobutylphosphonic acid 1.32 micrograms/side and phaclofen 0.535 and 2 micrograms/side) significantly affected locomotor activity. In rats pretreated with reserpine and alpha-methyl-p-tyrosine, picrotoxinin (0.0625 and 0.125 micrograms/side) did not significantly alter locomotor activity. Furthermore, when picrotoxinin (0.0625 micrograms/side) was combined with either the selective dopamine (DA) D1 agonist SKF38393 or the selective D2 agonist quinpirole, no significant alteration in locomotor function occurred. When SKF38393 and quinpirole were coadministered, significant stimulation occurred which was further enhanced by the addition of picrotoxinin. It is concluded that GABAA receptors, together with D1 and D2 receptors, play a major role in modulating the control of motor function by the Acb of rats.

alpha-Interferon has been shown to be the most promising antiviral agent in the treatment of chronic hepatitis B virus infection in Caucasian patients. The experience with recombinant interferon alfa-2a and alfa-2b in four randomized controlled trials in Chinese adults and children is reviewed here. alpha-Interferon alone has little long-term benefit in the treatment of Chinese patients with chronic hepatitis B virus infection, especially in patients who have normal or near normal serum aminotransferase levels. The response in patients with elevated aminotransferase levels appears to be better. The poor antiviral response in patients with normal aminotransferase levels is probably due to immunological tolerance to HBV induced by exposure to the virus in early life. Prednisone pretreatment does not seem to have any additional benefit to using interferon alone in these patients, while the effect in patients with elevated aminotransferase levels remains to be proven.

Quinolone antibiotics, which can be proconvulsant in susceptible patients, were found to inhibit the specific binding of the adenosine receptor ligands L-3H-N6-phenylisopropyladenosine (L-3H-PIA) and 3H-N-ethylcarboxamidoadenosine (3H-NECA) to rat brain synaptic membranes. The inhibitions were concentration dependent, and for both ligands the order of potency was rosoxacin greater than nalidixic acid greater than oxolinic acid greater than or equal to ciprofloxacin greater than norfloxacin greater than enoxacin: IC20 values (concentrations causing a 20% inhibition of specific binding) ranged from 30-35 microM to 1-3 mM. Hill coefficients were approximately 0.5, suggesting that the compounds are probably antagonists at these sites. Most of the compounds did not alter 3H-diazepam binding directly, although rosoxacin showed relatively strong, and enoxacin weak, concentration-dependent inhibition. At 50 microM the compounds enhanced the maximal gamma-aminobutyric acid (GABA) activation of 3H-diazepam binding to varying degrees, without altering the EC50 of activation, whereas at 200 microM they tended to reduce GABA activation. Most noteworthy was the large increase in GABA-stimulated 3H-diazepam binding caused by 50 microM nalidixic acid. The compounds did not alter the Ca2+/Cl- -dependent binding of 3H-glutamate, nor of the binding of the glutamate site-selective ligands 3H-kainate and alpha-3H-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (3H-AMPA); the uptake of the non-metabolized glutamate analogue D-3H-aspartate by cortical homogenates was also unaffected. The CNS side effects of these antibiotics may result, in part, from interaction with sites which mediate the inhibitory neurotransmission of adenosine and, possibly, GABA.

In this study, Sprague-Dawley rats were exposed in a TEM chamber to 20-MHz (HF-band) continuous-wave radiofrequency radiation (RFR) for 6 hr/day, 5 days/week up to 6 weeks. The average E-field intensity was 2686 +/- 164 V/m (mean +/- SD) and the calculated specific absorption rate was 0.3 W/kg. Randomly sampled rats killed on Days 8, 22, 39, and 42 after initiation of exposure showed no statistically significant differences from controls for body mass, spleen cell density, erythrocyte and leukocyte counts, hematocrit, hemoglobin, methemoglobin, erythrocyte fragility, bilirubin, creatinine, SGPT, alkaline phosphatase, calcium, sodium, potassium, and spleen cell chemiluminescence. Splenic mass differences were statistically significant (p less than 0.05) only on Day 22. Spleen to body mass ratios differed significantly between exposed and control groups on Days 22 and 39 (P less than 0.05 and P less than 0.025, respectively). Histologic examination of the rats revealed the successive accumulation of phagocytic cells, lymphoid proliferation, development of lesions, and tissue necrosis characteristic of respiratory mycoplasmosis. In a followup experiment, a separate set of rats was exposed for 6 weeks to identical levels of RFR. No significant differences were found in splenic parameters and spleen cell peroxidative activity. Histologic examination of these animals revealed no evidence of mycoplasma infection. The observed differences between exposed and control animals of the first experiment appear to have resulted from subclinical respiratory mycoplasmosis rather than exposure to RFR.

The oxidative response of murine spleen cells to secondary exposure to antigen was determined by luminol (5-amino-2,3-dihydro-1,4-pthalazinedione) amplified chemiluminescence, CL. BALB/cj and CBA/J mice were immunized with saline or an antigen solution of saline, luminol, and bovine serum albumin. Spleen cells were obtained from mice two and four days after immunization, and the CL response to in vitro antigenic exposure was measured for 35 minutes. At two days post-immunization, there was no difference in the CL of control and antigen-primed cells. By day four, the antigen-primed CL response differed significantly in both magnitude and time course from the primary antigen-stimulated response of the controls. This early development of differential CL response to antigenic challenge suggests a role for oxidative metabolic activity in the expression of the anamnestic immune response.

The effects of microwave radiation (2450 MHz, continuous wave, mean specific absorption rate of 103.5 +/- 4.2 W/kg) and convection heating on the nonphosphorylating oxidative metabolism of human peripheral mononuclear leukocytes (96% lymphocytes, 4% monocytes) at 37 degrees C were investigated. Metabolic activity, determined by chemiluminescence (CL) of cells challenged with luminol (5-amino-2,3-dihydro-1,4-phthalazinedione) linked to bovine serum albumin, was detected with a brightness photometer. A significant stimulation after microwave exposure (p less than 0.005) over total CL of matched 37 degrees C incubator controls was observed. A similar degree of stimulation compared to incubator controls was also detected after sham treatment. There was no significant difference between changes in total CL or stimulation indices of the microwave and sham exposed groups. It appears that exposure to microwave radiation, under normothermic (37 +/- 0.03 degrees C) conditions, has no effect on the oxidative metabolic activity of human peripheral mononuclear leukocytes. However, the significant differences between microwave or sham exposed cells and their respective incubator controls occurred because the temperature of the incubator controls did not exceed 35.9 degrees C and this temperature required 39 minutes to reach from 22 degrees C. Slow heating of incubator controls must be accounted for in thermal and radiofrequency radiation studies in vitro.

Influenza virus and Candida albicans allergenic extract elicit alterations in the oxidative metabolic activity of human mononuclear leukocytes (MNL). MNL preparations (greater than 96% lymphocytes, less than 4% monocytes) exposed in vitro to inactivated influenza virus displayed significantly enhanced oxidative activity, as demonstrated by luminol-amplified chemiluminescence (CL). MNL from donors who had received influenza vaccine and unimmunized donors showed similar levels of virus-stimulated CL. In contrast, MNL exposed to Candida (a macrophage dependent lymphocyte stimulator) displayed significant suppression in oxidative activity. Our findings support the hypothesis that oxidative activity holds an important role in the early events of the immune response.

Snellen chart visual acuity is thought to change very little up to age 60 years. However, any changes in contrast in the retinal and/or neural image with age may only be detected in low contrast and low luminance testing conditions. Only under these conditions does contrast significantly influence visual acuity measurements. In this pilot experiment we show that low contrast visual acuity is considerably worse (two lines of Snellen acuity) for an older group (N = 8, mean age 57) than for a younger group (N = 9, mean age 24.6) in spite of the fact that each subject was referred to the study with 6/6 (20/20) or better acuity. At conventional contrast and luminance levels there is no significant difference between the two groups. The results also suggest that a simple measurement of contrast sensitivity for a small spot of light may allow a contrast correction factor to account for both age and luminance level differences in the contrast vs. acuity function.