A clinical study of the patients with dengue hemorrhagic fever during the epidemic of 1996 at Lucknow, India

This paper describes the clinical findings in 206 patients with dengue fever (DF) or with dengue hemorrhagic fever (DHF) during the epidemic of 1996 at Lucknow. The age group affected most was 11 to 30 years and 21% of the patients were less than 10 years old. The male:female ratio was 1.9:1. The onset was abrupt in all the patients, severe frontal headache was observed in 97%, myalgia in 90%, skin rash in 40%, vomiting in 29% and arthralgia in knee and hip joints in 9%. Anuria was seen in two patients. Lymphadenopathy was noted in 14%, hepatomegaly in 4%, being associated with mild jaundice in one patient, and splenomegaly in 2% of the patients. Involvement of the heart and lungs was seen in one patient each and no case with encephalitis was recorded. Hemorrhages from various sites were observed in 54% patients and 17 patients had profound shock. The commonest bleeding site was gums. Profound shock was preceded by various warning signs, the commonest being sudden hypotension. Among the patients with profound shock the mortality was 47% while the overall fatality rate was 3.8%. A number of the risk factors existed for a long time in this part of the world, but what precipitated the present epidemic at this time, is not known.

Needle-free, non-adjuvanted skin immunization by electroporation-enhanced transdermal delivery of diphtheria toxoid and a candidate peptide vaccine against hepatitis B virus

To explore the feasibility of non-adjuvanted, needle-free skin immunization, we examined the immune responses of mice immunized by three routes with two antigens (Ag) differing in molecular size and lipophilicity. Diphtheria toxoid (DT) or a myristylated peptide (MYR) administered either by transdermal electroporation (EP) or intradermally (i.d.) with a needle elicited markedly different responses. The EP route elicited higher responses to MYR than i.d. immunization, but lower responses to DT. Intraperitoneal (i.p.) immunization evoked responses against MYR that were higher than those evoked by EP. It was inferred that EP is a promising technique for non-adjuvanted skin immunization, specially with low molecular weight, weakly immunogenic Ag.

Correlation of acetylator phenotype with peripheral, autonomic and central neuropathy in Northern Indian non-insulin-dependent diabetes mellitus patients

OBJECTIVES

Genetic susceptibility to diabetic neuropathy has been suspected and tentatively explored; however, diabetic autonomic and central neuropathies are poorly investigated areas. Previous trials correlating types of diabetes and diabetic neuropathy with acetylator dimorphisms have not been conclusive. The present study was designed to test peripheral neuropathy, autonomic neuropathy and integrity of central conduction pathways in patients of non-insulin-dependent diabetes mellitus (NIDDM), and to correlate the findings with the acetylator phenotype.

METHODS

Twenty-six patients of NIDDM with stable glycaemic control and 11 age- and sex-matched control subjects were recruited, clinically examined and investigated with glycaemic and lipid profile, renal function tests, nerve conduction studies (sensory and motor), auditory brain stem evoked responses (ABERs) and somatosensory evoked potentials (SEPs). Acetylator status of the subjects was determined by sulphadimidine test.

RESULTS

Out of 26 NIDDM patients, eight (30.7%; group 1A) were slow acetylators and 18 (69.3%; group 1B) were fast acetylators. The distribution of slow and rapid acetylators in both the groups was similar. Glycaemic and lipid profiles and 24-h urinary albumin excretion in groups 1A and 1B were also similar. Motor nerve conduction velocity, latency of F wave, sensory nerve conduction and amplitudes of sensory nerve action potentials were not different between fast and slow acetylator NIDDM patients. On testing for ABERs, there were no statistically significant differences in peak latencies of waves I, III and V; interpeak latencies (IPLs) I-III, III-V and I-V; amplitude of waves I, III and V on both sides between NIDDM patients and controls. However, peak latencies of wave III (P < 0.01), wave V (P < 0.005), IPLs I-III and I-V (P < 0.005), IPLs III-V (P < 0.05), and amplitudes of wave I (P < 0.05) and wave V (P < 0.05) on the left side were significantly different in slow acetylator NIDDM patients. Increase on the right side for the same group was statistically significant for IPLs I-III and I-V (P < 0.05). SEPs showed no statistically significant difference between NIDDM patients and controls, and slow and fast acetylator NIDDM patients.

CONCLUSIONS

No significant association of acetylator status with peripheral neuropathy in NIDDM subjects was observed in the present study. However, central neural conduction, primarily tested by ABERs, was significantly delayed in slow acetylators compared with fast acetylator NIDDM patients. Hence, there may be a predisposition to neuropathy in this group of patients, and such a predisposition may be better detected by studying central rather than peripheral nervous conduction pathways in NIDDM patients.

Portal hypertension due to extensive hepatic cysts in autosomal dominant polycystic kidney disease

Liver cysts are a well-recognized feature of autosomal dominant polycystic kidney disease (ADPKD) and occur in 77% of patients more than 60 years old. Serious sequelae, however, are rare, the two most common complications being pain and cyst infections. Portal hypertension has been reported in ADPKD due to the rare presence of congenital hepatic fibrosis. We report a case of ADPKD in a patient who had portal hypertension due to distortion of portal vein and venules by extensive hepatic cysts.

Clustering of impaired glucose tolerance, hyperinsulinemia and dyslipidemia in young north Indian patients with coronary heart disease: a preliminary case-control study

Metabolic insulin resistance syndrome is a critical factor in the pathogenesis of atherosclerosis and coronary heart disease in Indians. In a preliminary case-control study, 44 young patients (age < 40 years) with coronary heart disease (angina, myocardial infarction), not previously diagnosed to have diabetes mellitus, were recruited seven days to six weeks after the cardiac event (group I), and compared to 20 healthy subjects (group II). After recording history and anthropometric data, they were subjected to oral glucose tolerance test. Each group was divided into A and B subgroups according to the magnitude of impaired glucose tolerance. Hypertension was recorded in 11 (25%) patients in group I, while all the subjects in group II were normotensive (p < 0.05). Groups IB and IIB, consisting of subjects with impaired glucose tolerance displayed significantly high post-load blood glucose values. After excluding patients with the family history of diabetes mellitus, there were 13 (39%) and 3 (17%) patients with impaired glucose tolerance in groups I and II, respectively. Total cholesterol and low-density lipoprotein cholesterol levels were higher in group I as compared to group II (p < 0.01). Group IB showed highest mean values of total cholesterol, triglycerides, low-density lipoprotein cholesterol and lowest level of high-density lipoprotein cholesterol as compared to other subgroups. Serum insulin levels at 30 and 90 minutes were significantly higher in group I (p < 0.05). Group IB and IIB showed higher insulin values at 90 minutes when compared to group IA (p < 0.05) and IIA (p < 0.05). Elevated serum insulin values at 90 minutes during oral glucose tolerance test could differentiate among both groups and subgroups, except IB versus IIB. The study demonstrates significantly high prevalence of hypertension, obesity, impaired glucose tolerance, hyperinsulinemia and dyslipidemia, suggesting fully developed metabolic insulin resistance syndrome in young north Indian patients with manifest coronary heart disease.

Synthesis, physicochemical properties, anticonvulsant activities, and GABA-ergic and voltage-sensitive calcium channel receptor affinities of alpha-substituted N-benzylamides of gamma-hydroxybutyric acid. Part 4: Search for new anticonvulsant compounds

In a search for new anticonvulsant compounds, two series of N-benzylamides of alpha-(benzylamino)-gamma-hydroxybutyric acid (series A) and alpha-(2-phenylethylamino)-gamma-hydroxybutyric acid (series B), were investigated in maximal electroshock (MES), subcutaneous metrazole, and rotorod toxicity assays. The most potent anticonvulsant compounds were alpha-(benzylamino)-gamma-hydroxybutyric acid N-benzylamide (3) and N-(2-chlorobenzylamide (4) with median effective (ED50) doses 63.0 mg/kg and 54.0 mg/kg, respectively. alpha-(4-Phenylpiperazinyl)-gamma-hydroxybutyric acid N-(4-methylbenzyl)amide (17) and alpha-(benzylpiperazinyl-gamma-hydroxy-butyric acid N-(4-methylbenzyl)amide (18) were also tested for their ability to potentiate [3H]-muscimol binding and to inhibit [35S]-TBPS binding (as indices of GABA-A receptor potentiation). Amide 17 exhibited activity at the GABA-A complex which may be the mechanism by which the anticonvulsant effect of this compound is mediated. The N-benzylamides of alpha-(benzylamino)-gamma-hydroxybutyric acid (3-9) were also evaluated for their ability to displace [3H]-nitrendipine from voltage-sensitive calcium channel (VSCC) receptors isolated from rat cortex.

Length and time scale divergences at the magnetization-reversal transition in the Ising model

The divergences of both the length and time scales, at the magnetization-reversal transition in the Ising model under a pulsed field, have been studied in the linearized limit of the mean field theory. Both the length and time scales are shown to diverge at the transition point and it has been checked that the nature of the time scale divergence agrees well with the result obtained from the numerical solution of the mean field equation of motion. Similar growths in length and time scales are also observed, as one approaches the transition point, using Monte Carlo simulations. However, these are not of the same nature as the mean field case. Nucleation theory provides a qualitative argument that explains the nature of the time scale growth. To study the nature of growth of the characteristic length scale, we have looked at the cluster size distribution of the reversed spin domains and have defined a pseudocorrelation length that has been observed to grow at the phase boundary of the transition.

Increased arterial stiffness in children with a parental history of hypertension

The vascular dynamics of children with a parental history of hypertension has not been defined. The purpose of the current study was to determine whether or not these children have different arterial stiffness compared to the offspring of normotensive parents. One hundred healthy, nonobese subjects (ages 10-21 years) were divided into two groups of 50. Group A included the offspring of hypertensive patients and group B the offspring of normotensive parents. The variables studied were body surface area, blood pressure, and systolic and diastolic diameters of the aortic and carotid arteries as well as maximum velocity flow of these vessels. Carotid and aortic stiffness were calculated. Children and adolescents with a parental history of hypertension had higher carotid stiffness and smaller carotid diameters. These differences continued to be significant when correcting for body surface area. A higher blood pressure and a greater body surface area were also found.

Comparison of endoscopic ligation and propranolol for the primary prevention of variceal bleeding

BACKGROUND AND METHODS

We compared propranolol therapy and endoscopic ligation for the primary prevention of bleeding from esophageal varices. This prospective, controlled trial included consecutive eligible patients who had large varices (>5 mm in diameter) that were at high risk for bleeding. The patients were assigned to either propranolol therapy, at a dose sufficient to decrease the base-line heart rate by 25 percent, or variceal ligation, to be performed weekly until the varices were obliterated or so reduced in size that it was not possible to continue treatment.

RESULTS

Of the 89 patients, 82 of whom had cirrhosis of the liver, 44 received propranolol and 45 underwent variceal ligation. The mean (+/-SD) duration of follow-up in each group was 14+/-9 and 13+/-10 months, respectively. The mean time required to achieve an adequate reduction in the heart rate was 2.5+/-1.7 days; the mean number of sessions needed to complete variceal ligation was 3.2+/-1.1. After 18 months, the actuarial probability of bleeding was 43 percent in the propranolol group and 15 percent in the ligation group (P=0.04). Twelve patients in the propranolol group and four in the ligation group had bleeding. Three of the four in the ligation group had bleeding before their varices had been obliterated. Nine patients in the ligation group had recurrent varices, a mean of 3.7 months after the initial treatment. Five patients in each group died; bleeding from the varices was the cause of death of four patients in the propranolol group and of three in the ligation group. There were no serious complications of variceal ligation; in the propranolol group, treatment was stopped in two patients because of side effects.

CONCLUSIONS

In patients with high-risk esophageal varices, endoscopic ligation of the varices is safe and more effective than propranolol for the primary prevention of variceal bleeding.

Atherosclerosis in Indians and lipoprotein (a)

Indians, both immigrant or native, are predisposed to develop a cluster of risk factors, and consequently are more prone to manifest CAD as compared to several other ethnic groups. Lipid profile in them is not characterised by hypercholesterolemia, instead the atherogenic profile is denoted by high TG and low HDL-c levels. Lp(a), is a recently discovered important independent and inheritable risk factor for atherosclerosis. It plays an important role in atherogenesis, and acts as a prothrombotic agent as well. Levels of Lp(a) are significantly higher in Indians subjects as well as their offsprings. Thus, Lp(a) is likely to have substantial role in development of early and extensive atherosclerosis in Indians. It is essential to include Lp(a) in battery of tests for evaluation of coronary risk especially in Indians. Further studies shall unravel the full ramifications of adverse effects of this lipoprotein.

A comparative study in rats of the in vitro and in vivo pharmacology of the acetylcholinesterase inhibitors tacrine, donepezil and NXX-066

The in vitro and in vivo effects of the novel acetylcholinesterase inhibitors donepezil and NXX-066 have been compared to tacrine. Using purified acetylcholinesterase from electric eel both tacrine and donepezil were shown to be reversible mixed type inhibitors, binding to a similar site on the enzyme. In contrast, NXX-066 was an irreversible non-competitive inhibitor. All three compounds were potent inhibitors of rat brain acetylcholinesterase (IC50 [nM]; tacrine: 125 +/- 23; NXX-066: 148 +/- 15; donepezil: 33 +/- 12). Tacrine was also a potent butyrylcholinesterase inhibitor. Donepezil and tacrine displaced [3H]pirenzepine binding in rat brain homogenates (IC50 values [microM]; tacrine: 0.7; donepezil: 0.5) but NXX-066 was around 80 times less potent at this M1-muscarinic site. Studies of carbachol stimulated increases in [Ca2+]i in neuroblastoma cells demonstrated that both donepezil and tacrine were M1 antagonists. Ligand binding suggested little activity of likely pharmacological significance with any of the drugs at other neurotransmitter sites. Intraperitoneal administration of the compounds to rats produced dose dependent increases in salivation and tremor (ED50 [micromol/kg]; tacrine: 15, NXX-066: 35, donepezil: 6) with NXX-066 having the most sustained effect on tremor. Following oral administration, NXX-066 had the slowest onset but the greatest duration of action. The relative potency also changed, tacrine having low potency (ED50 [micromol/kg]; tacrine: 200, NXX-066: 30, donepezil: 50). Salivation was severe only in tacrine treated animals. Using in vivo microdialysis in cerebral cortex, both NXX-066 and tacrine were found to produce a marked (at least 30-fold) increase in extracellular acetylcholine which remained elevated for more than 2 h after tacrine and 4 h after NXX-066.

Hyperinsulinemia and dyslipidemia in non-obese, normotensive offspring of hypertensive parents in northern India

Insulin resistance contributes to initiation and acceleration of hypertension and atherosclerosis. This study attempted to detect occurrence of pre-hypertensive metabolic abnormalities, including hyperinsulinemia, in the offspring of hypertensive patients. Thirty-eight healthy offspring of hypertensive parents (group I, mean age 23.6+/-3.7 years) and 18 control offspring of normotensive parents (group II, mean age 24.2+/-2.8 years) were clinically examined, subjected to oral glucose tolerance test (OGTT), and the samples were analysed for blood glucose, insulin and lipid profile. Subjects in group I with fasting serum insulin <90 nmol/L constituted group Ia (n = 23, 62%) and those with >90 nmol/L constituted group Ib (n = 15, 38%). Both groups consisted of non-obese and normotensive subjects matched for body mass index and waist-hip ratio. There were no statistically significant differences in blood glucose levels between groups Ia, Ib and II during OGTT. Serum insulin levels during OGTT in group I were significantly higher than in group II (p<0.05), except at 30 min. Fasting insulin and 2 h post-OGTT insulin in group Ib were significantly higher than the other groups. Serum triglyceride levels, though within normal range, were higher in group I than group II (p<0.01). Similarly, high-density lipoprotein cholesterol levels in groups Ia and Ib were lower than those observed in group II (p<0.01). In conclusion, non-obese, normotensive offspring of hypertensive parents were observed to be hyperinsulinemic and dyslipidemic at an early age. These metabolic abnormalities may be associated with hypertension, glucose intolerance and accelerated atherosclerosis in adulthood.

Elevated levels of IL-8 in dengue hemorrhagic fever

Dengue virus causes dengue fever, a mild febrile illness, and at times dengue hemorrhagic fever (DHF), a severe illness the pathogenesis of which is not fully understood. Given the crucial roles played by interleukin-8 (IL-8) as a chemoattractant cytokine and in inflammatory processes, levels of circulating IL-8 in the sera and IL-8 mRNA in the peripheral blood mononuclear cells (PBMC) were measured in 99 patients of a recent dengue epidemic that occurred in India in 1996 and in 21 normal healthy controls. Twenty-six of the patients had dengue fever (DF) and the remaining 73 were diagnosed as having different grades of DHF. All the control normal sera were negative for IL-8, so were their PBMC for IL-8 mRNA. Increased levels of IL-8 in the sera and IL-8 mRNA in their PBMC were observed in patients with severe illness of DHF grades III and IV. Only two out of 26 patients of DF and one out of 10 DHF grade I patient were positive for IL-8 and all three deteriorated to DHF grade IV within 24 hr. All six patients of DHF grade IV who died had higher serum level of IL-8 above 200 pg/ml, the highest being 5,568 pg/ml in one patient; the presence of mRNA for IL-8 was very high in all patients. A striking correlation was observed between increased levels of IL-8 and severe DHF, with greater levels in patients with increased grade of the disease and death. These results suggest that IL-8 may have an important role and may be an indicator of increasing severity of the disease and death.

Oesophageal motility and gastro-oesophageal reflux: effect of variceal eradication by endoscopic sclerotherapy

Endoscopic injection sclerotherapy (EIS) is known to produce oesophageal structural and motility changes; however, alterations in frequency and severity of gastro-oesophageal reflux (GER) following EIS have not been investigated in detail. We studied 22 patients with cirrhosis and oesophageal varices before EIS and 26 after variceal eradication with intravariceal EIS using manometry and 24 h pH monitoring. The post-EIS group had reduced oesophageal sphincter pressure (19.2+/-11.4 vs 26.1 +/-16.4 mmHg, P< 0.05) and slower velocity of oesophageal peristalsis (2.47+/-0.71 vs 3.06+/-0.77 cm/s, P< 0.01) than the pre-EIS patients. There was no difference in the amplitude or duration of the contraction. Abnormal contraction wave-forms were observed more frequently in post-EIS than in the pre-EIS patients (3/22 vs 12/26, P< 0.05). Various quantitative parameters for GER were not increased in post-EIS compared with pre-EIS patients. Abnormal GER was present in nine of 21 pre-EIS and eight of 17 post-EIS patients (no significant difference). These results suggest that although persistent oesophageal motility changes are frequent after intravariceal EIS, these do not lead to a significant increase in GER.

An investigation of the possible interaction of clomethiazole with glutamate and ion channel sites as an explanation of its neuroprotective activity

The activity of the neuroprotective agent clomethiazole at glutamate and ion channel sites has been investigated. Dizocilpine (3.25 mg/kg intraperitoneally) provided almost total protection against the damage produced by infusion of N-methyl-DL-aspartate (NMDLA; 75 micrograms) into the right hippocampus. In contrast, clomethiazole (96 mg/kg intraperitoneally) was without effect. Using ligand binding techniques, no evidence was found for clomethiazole interacting with NMDA, AMPA or sigma binding sites. Clomethiazole did inhibit the stimulatory effect of the metabotropic glutamate receptor agonist 1S3R-aminocyclopentone-1,3-dicarboxylic acid (ACPD) on phosphoinositol hydrolysis, but only at a concentration of 10(-3) M, which is unlikely to have functional relevance. Clomethiazole was also without effect on ligand binding to Ca2+ channels (N- or L- type), Na+ channels or ATP-sensitive K+ channels. Potentiation of GABA function therefore remains the most plausible explanation for the neuroprotective activity of clomethiazole.

AIDS cholangiopathy

A 45-year-old man presented with diarrhea and profound weight loss over one year. His serum alkaline phosphatase was raised and ultrasonography showed dilated intrahepatic biliary ducts and upper part of common bile duct (CBD). ERCP showed papillary stenosis, dilated CBD, stricture at the confluence and saccular dilatation of the left intrahepatic biliary ducts. He was found HIV-positive. Duodenal biopsy, rectal biopsy and stool examination could not identify any opportunistic organism.

Theophylline clearance in undernourished asthma patients

Theophylline clearance is altered by many drugs and diseases that may be associated with undernutrition. Therefore, we studied theophylline clearance in 12 undernourished [body mass index (BMI) less than 19] and 12 well nourished asthma patients (body mass index more than 19). Uncoated theophylline tablet (200 mg, 300 mg dose 5 mg/kg approx) was administered orally to each asthma patient after 12 hours overnight fasting. Serum theophylline concentrations were estimated after 2, 4, 6, 8 hours of drug administration and it was calculated from log conc: time curve. Undernourished asthma patients had a mean theophylline clearance of 85.6 (SE = 6.2) ml/hr/kg while it was 125.6 (SE = 3.8) ml/hr/kg in well-nourished asthma patients. The difference between two groups was highly significant (p < 0.01). We conclude that theophylline clearance is significantly lower in undernourished asthma patients and they will require a lower maintenance dose of theophylline.

Production of cytotoxic factor by peripheral blood mononuclear cells (PBMC) in patients with dengue haemorrhagic fever

A unique cytokine, human cytotoxic factor (hCF), has been shown to occur in the sera of patients with dengue fever (DF) and dengue haemorrhagic fever (DHF). The present study was undertaken to investigate the ability of fresh PBMC of such patients to produce hCF. The PBMC were cultured for 24 h and the culture supernatants (CS) were analysed for the presence of hCF by cytotoxicity assay, competitive ELISA and dot blot tests. In 90% of 246 cases CS were positive for hCF by the three tests. CS were positive for hCF in PBMC collected from days 1-20 of illness but not at later periods. Higher cytotoxic activity was observed in CS of days 1-4 of illness and was highest in cases of DHF grade IV and lowest in cases of DF. Dot blot hybridization of RNA extracted from the PBMC of the patients showed the presence of mRNA for hCF in 94% of cases. A similar number of patients showed the presence of hCF in situ in the PBMC smears by fluorescent antibody technique. hCF was found only in CD4+ T cells. The findings thus present direct evidence of the production of hCF by CD4 T cells of cases of DF/DHF.

Vaccination of langur monkeys (Presbytis entellus) against Leishmania donovani with autoclaved L. major plus BCG

The protective potential of killed Leishmania major (ALM) along with BCG was evaluated against L. donovani in Indian langur monkeys in single and triple dose schedules. A delayed protection was observed in monkeys after a single dose schedule of ALM (3 mg)+BCG (3 mg) given intradermally 2 months before intravenous challenge with L. donovani. Triple dose schedule each of 1 mg ALM + 1 mg BCG was more effective. The status remained unchanged until the end of the experiment (approximately 8 months). The study indicates that a combination of ALM + BCG may be a good candidate vaccine for exploiting against human Kala-azar.

Genetic alterations in brain tumors identified by RAPD analysis

We report the utility of random amplified polymorphic DNA (RAPD) analysis for identifying subtle genomic alterations in meningiomas and gliomas by comparing the DNA band profile of tumor vis-à-vis its constitutional counterpart. Twenty out of the 29 decanucleotide GC-rich random primers utilized for the RAPD analysis of meningiomas revealed alteration(s) in the tumor genome. In gliomas, changes were detected by 16 of the 18 primers. While all the seven meningioma samples exhibited alterations in tumor DNA, changes were evident in 21 of the 24 glioma cases. These alterations in tumor DNA included the loss of a normal band, appearance of a new band and amplification of a pre-existing band. Many primers detected more than one alterations in a given tumor. Our approach, which covers the range from 0.4 to 2 kb, besides detecting a significant number of changes in a spectrum of brain tumors, complements existing DNA fingerprinting methods, such as microsatellite mapping (less than 0.4 kb) and Southern blotting (over 2 kb), for detecting genetic alterations in tumors.

Relationship of manometric findings to symptomatic response after pneumatic dilation in achalasia cardia

BACKGROUND

Achalasia cardia is usually treated by pneumatic dilation or surgical esophagomyotomy. The role of esophageal manometry for objective assessment of symptom response is controversial.

AIM

To study the relationship between symptoms and manometric parameters before and after pneumatic dilation in patients with achalasia cardia.

METHODS

Sixteen patients with achalasia cardia underwent esophageal manometry before and after undergoing pneumatic dilation. At each time, lower esophageal sphincter (LES) pressure and mean basal esophageal-gastric pressure gradient (MIEP-MIGP) were measured.

RESULTS

Good symptom response was obtained in 12 of 16 patients. Median (range) LES pressure fell from 42 (17-51) mmHg to 18 (8-39) mmHg in those patients with a good response, and from 51 (25-68) mmHg to 29.5 (23-42) mmHg in those who responded poorly. Mean intraesophageal pressure fell below mean intragastric pressure in both the groups.

CONCLUSIONS

Esophageal manometry does not correlate with symptom improvement after pneumatic dilation in achalasia cardia. Dysphagia may persist in spite of reversal of the MIEP-MIGP gradient.

Hyperinsulinemia in non-obese, non-diabetic subjects with isolated systolic hypertension

To investigate the inter-relationship of hyperinsulinemia and isolated systolic hypertension, 15 patients with isolated systolic hypertension (Group I) were compared to those having systolic and diastolic hypertension (Group II), and 14 age- and sex-matched controls (Group III). Significantly high triglycerides and total cholesterol were observed in Groups I and II (p < 0.001) and low high-density lipoprotein cholesterol in Group II (p < 0.001), when compared to controls. Significantly high number of patients had impaired glucose tolerance (80%; p = 0.0002 and 60%; p = 0.05) on oral glucose tolerance test in Groups I and II, respectively. Higher blood glucose values were observed in Group I as compared to Group III, at 0, 30, 60 (p < 0.05) and 120 minutes (p < 0.001). Subjects in all the three groups showed fasting normo-insulinemia. At 60 minutes during oral glucose tolerance test, higher insulin levels were seen in Groups I and II as compared to controls (p = NS). Peak insulin levels and area under curve for insulin were higher in Groups I and II as compared to controls (p = NS). The observations of the present study indicate that, similar to systolic and diastolic hypertension, several features of insulin resistance syndrome such as hyperinsulinemia, dyslipidemia and glucose intolerance accompany isolated systolic hypertension.

Long-term high immune response to diphtheria toxoid in rodents with diphtheria toxoid conjugated to dextran as a single contact point delivery system

Cross-linked dextran beads were used as a carrier for development of a 'single-contact' vaccine delivery system. Diphtheria toxoid (DT) was covalently coupled to dextran beads (DEX-DT conjugate). The conjugate was immunoreactive with antibodies raised against native DT. Immunization of rats with DEX-DT conjugate generated on average 24 times higher antibody titres against diphtheria toxoid than immunization with the conventional DT absorbed on alum. The immune response was sustained for 9 months, with gradual decline of antibody titres thereafter. Significant antibody titres were measurable in rats after 1 year of immunization. DEX-DT had neither acute nor long-term adverse effects on the health of animals, as evidenced by local reactions, general behaviour, food intake, body weight gain and survival compared with controls.

Biphasic testosterone delivery profile observed with two different transdermal formulations

PURPOSE

Our long-term goal is to develop formulations for pulsatile testosterone (T) delivery. T has been reported earlier to show biphasic pharmacokinetics in humans by Mazer et al, as well as biphasic permeation across excised rat skin by our group. We examined two kinds of formulations to evaluate their delivery profiles and to assess whether differences in the formulation approach affect pharmacokinetics in animal models.

METHODS

One formulation consisted of T and a polymer blend dissolved in isopropanol; administered by dispensing the solution on the skin to cast a film in situ. The other was an adhesive-dispersion patch. In vitro release from the patch was evaluated using a flow-through cell interfaced with an HPLC pump and UV detector. Single dose pharmacokinetics were evaluated in castrated Wistar rats and bonnet monkeys immunized against gonadotropin-releasing hormone to deplete endogenous T.

RESULTS

Two maximas were observed in the T release profile from the patch and in serum concentration versus time profiles in both animal models on application of either formulation. The relative magnitudes of the two maximas and the time interval separating them were different in the case of each formulation.

CONCLUSIONS

Both formulations result in biphasic pharmacokinetics of T in the animal models studied. Discrete maximas presumably correlate with "burst" and "sustained" phases of drug release.

Intersubject variability of serum theophylline concentration after single dose of uncoated controlled release theophylline tablet administration in asthmatic patients

Various reports indicate significant intersubject variation in the rate of absorption of controlled release theophylline products that are commercially available. Serum theophylline concentration was estimated in 17 asthma patients treated with controlled release theophylline tablet (mean dose: 5.6 +/- 0.6 mg/kg, mean body wt: 49.82 +/- 9.05 kg). The mean maximal concentration (Cmax) of 5.57 +/- 1.65 micrograms/ml occurred at mean time of maximal concentration (Tmax) of 3.3 +/- 1.36 (mean +/- SD) hours. Mean minimal concentration (Cmin) was 3.164 +/- 1.1 micrograms/ml (mean +/- SD) at mean time of minimal concentration (Tmin) of 5.77 +/- 1.77 (mean +/- SD) hours. The mean percent fluctuation was 112.95 +/- 183.45 (mean +/- SD) but in 4 out of 17 patients, percent fluctuation was 107.29 to 823.10. Therefore, 23.5% patients treated with controlled release theophylline tablet had wide fluctuations in serum theophylline concentration.

A study of the neurotoxic effect of MDMA ('ecstasy') on 5-HT neurones in the brains of mothers and neonates following administration of the drug during pregnancy

1. It is well established that 3,4-methylenedioxymethamphetamine (MDMA or 'ecstasy') is neurotoxic and produces long term degeneration of cerebral 5-hydroxytryptamine (5-HT) nerve terminals in many species. Since MDMA is used extensively as a recreational drug by young people, it is being ingested by many women of child bearing age. We have therefore examined the effect of administering high doses of MDMA to rats during pregnancy on the cerebral content of both the dams and the neonates. 2. MDMA (20 mg kg-1, s.c.) was injected twice daily on days 14-17 of the gestation period. The initial dose produced a marked hyperthermic response in the dam which was progressively attenuated in both peak height and area under the curve following further doses of the drug. The body weight of the dams decreased during the period of treatment. 3. There was a modest decrease in litter size (-20%) of the MDMA-treated dams. 4. The concentration of 5-HT and its metabolite 5-HIAA was decreased by over 65% in the hippocampus and striatum and 40% in the cortex of the dams 1 week after parturition. In contrast, the content of 5-HT and 5-HIAA in the dorsal telencephalon of the pups of the MDMA-treated dams was the same as that seen in tissue from pups born to control animals. 5. Administration of MDMA (40 mg kg-1, s.c.) to adult rats increased thiobarbituric acid reacting substances (TBARS) in cortical tissue 3 h and 6 h later, indicating increased lipid peroxidation. No increase in TBARS was seen in the cortical tissue of 7-10 day neonates injected with this dose of MDMA 3 h or 6 h earlier. 6. The data suggest that exposure to MDMA in utero during the maturation phase does not produce damage to 5-HT nerve terminals in the foetal rat brain, in contrast to the damage seen in the brains of the mothers. This may be due to MDMA being metabolized to free radical producing entities in the adult brain but not in the immature brain or, alternatively, to more effective or more active free radical scavenging mechanisms being present in the immature brain.

Esophageal achalasia presenting during pregnancy

We report a woman with achalasia cardia who developed dysphagia for the first time during pregnancy. She was initially mistakenly treated elsewhere as hyperemesis gravidarum. The diagnosis and treatment of achalasia during pregnancy is reviewed.

Relationship of anterior and posterior subcutaneous abdominal fat to insulin sensitivity in nondiabetic men

Recent studies from our reveal that adipose tissue (AT) in the subcutaneous abdominal region is the most important determinant of peripheral and hepatic insulin sensitivity. Because of different anatomic and physiologic characteristics of anterior and posterior subcutaneous abdominal AT, we investigated the relationship of the masses of each compartment, as determined by magnetic resonance imaging, to insulin sensitivity (using euglycemic hyperinsulinemic glucose clamp technique), and other anthropometric variables. Thirty-four healthy men with varying ranges of obesity were recruited for the study. The mass of posterior subcutaneous abdominal AT was approximately 1.6 times more than that of the anterior compartment, and these masses accounted for 12.9% and 8.2% of the total body fat mass, respectively. All anthropometric variables, including body mass index (BMI), waist-to-hip circumference ratio (WHR), skin-fold thicknesses, and intraperitoneal AT mass were more significantly related to the posterior than the anterior subcutaneous abdominal AT mass. Compared to the anterior compartment mass, the posterior compartment mass displayed stronger relationship with insulin-mediated glucose disposal (Rd) (r = -0.44, p = 0.009, and r = -0.76, p = 0.0001, respectively) as well as with residual hepatic glucose output during the 40 mU.m-2.min-1 insulin infusion (r = 0.39, p = 0.02, and r = 0.53, p = 0.001, respectively). After adjusting for total body fat, the Rd values showed a significant partial correlation with the posterior subcutaneous abdominal AT mass (r = 0.52, p = 0.002). To conclude, posterior subcutaneous abdominal AT mass is more important determinant of peripheral and hepatic insulin sensitivity than the anterior subcutaneous abdominal AT.

Cognitive function in younger type II diabetes

OBJECTIVE

To examine central nervous system involvement as a possible complication of diabetes by performing a comprehensive neuropsychological evaluation of relatively young (age < 55 years) NIDDM patients and a group of control subjects.

RESEARCH DESIGN AND METHODS

A cross-sectional comparative study of 28 patients, with duration of diabetes 5-18 years (mean +/- SD +/- 3.2 years), screened for acceptable glycemic control and absence of hypoglycemia on the day of examination, compared with 28 demographically similar, nondiabetic control subjects. Neuropsychometric tests performed were Mini-Mental Status Examination (MMSE), Neurobehavioral Cognitive Status Examination (NCSE), and P300 latencies (endogenous evoked potentials).

RESULTS

Seven (25.0%) patients reported history suggestive of cognitive impairment during day-to-day activities, and 17 (60.7%) had distal symmetrical polyneuropathy. Average P300 latencies were significantly delayed among the diabetic patients compared with the control subjects (349.5 +/- 28.2 vs. 312.9 +/- 19.3 ms; t = 5.68, P < 0.001). Although there was no significant difference in MMSE scores, compared with control subjects significantly more patients had impairment in NCSE tests of attention (chi 2 = 7.38, P < 0.01), repetition (chi 2 = 4.073, P < 0.05), and memory (chi 2 = 5.83, P < 0.05), while there was no significant difference in tests of comprehension, naming, construction, and calculation. Duration of diabetes, HbA1c levels, and the presence of distal symmetrical polyneuropathy among patients each did not correlate with any of the parameters of cognitive function evaluated. Higher blood glucose levels during the electrophysiological testing were associated with less delay in P300 latencies among the patients.

CONCLUSIONS

Central nervous system impairment, manifesting as mild impairments in certain cognitive skills, should be recognized as a possible complication of long-standing NIDDM, even in relatively younger individuals.

Release of reactive oxygen intermediates by dengue virus-induced macrophage cytotoxin

Dengue type 2 virus (DV) induces a subpopulation of T lymphocytes of mice to produce a cytokine, cytotoxic factor (mCF), which induces H-2A positive macrophages to produce macrophage cytotoxin (CF2). The present study was undertaken to investigate the mechanism of cytotoxicity of CF2. It was observed that CF2 induced production of superoxide anion (O2-) and hydrogen peroxide (H2O2) by the spleen cells of mice in vitro and in vivo. The maximum production of O2- (260 +/- 10 nM/4 x 10(6) cells) was at 45 minutes while that of H2O2 was at 90 minutes after inoculation of CF2. Pretreatment of mice or spleen cells with anti-CF2-antisera inhibited O2- and H2O2 production in a dose-dependent manner. Superoxide dismutase (SOD) inhibited O2- production and cytotoxicity while H2O2 production was increased by increasing SOD concentration in the culture. This indicated that O2- production is necessary for the cytotoxic activity of CF2. Pretreatment of the cells with Ca2+ channel blocking drugs, nifedipine or verapamil, inhibited CF2-induced O2- and H2O2 production in a dose-dependent manner. We have shown earlier that the cytotoxic activity of CF2 is known to be Ca2+ dependent and CF2-induced production of nitrite and the cytotoxicity is inhibited by NG-monomethyl-L-arginine. Thus, it is suggested that O2- and nitrite are necessary for cell killing by CF2 in a Ca(2+)-dependent manner and the killing may possibly be by generation of peroxynitrite.

Electrophysiologic differences in young patients with atrial fibrillation. Influence of preexcitation

Paroxysmal atrial fibrillation is a common arrhythmia, which may occur in young patients without known structural heart disease, with or without preexcitation. Elimination of an accessory pathway in these patients may prevent not only orthodromic and antidromic tachycardia but also atrial fibrillation. However, abnormalities of atrial conduction and refractoriness have been reported, suggesting that atrial fibrillation may still recur in these patients. In a review of all electrophysiologic studies performed at the authors' institution since January 1990 in patients under age 60 years of age without identifiable heart disease, 24 patients with atrial fibrillation were identified whose electrophysiologic measurements of a right atrial conduction and effective refractory period of the right atrium and accessory pathway were in sinus rhythm. Of these patients, 12 had preexcitation and the other 12 did not. These patients were compared with age- and sex-matched control subjects, 12 with preexcitation without atrial fibrillation and 13 without preexcitation or atrial fibrillation, respectively. Electrophysiologic abnormalities were noted in patients with atrial fibrillation depending on the presence or absence of preexcitation. In patients with preexcitation, these abnormalities were a shorter refractory period of the right atrium (212 +/- 33 ms) and of the accessory pathway (251 +/- 27 ms), compared with control subjects (241 +/- 27 ms, P < .05 and 306 +/- 61 ms, P < .02, respectively). In patients without preexcitation, conduction abnormality in the form of prolonged atrial conduction time when compared with control subjects (48 +/- 26 ms vs 31 +/- 10 ms, P < .05) was noted. These findings may influence the type of antiarrhythmic drug used in these patients, and if confirmed in a larger study, they may lead to a better understanding of factors influencing the development of atrial fibrillation in young patients.

Production of nitrite by dengue virus-induced cytotoxic factor

Dengue type 2 virus (DV) infection induces production of a cytokine, the cytotoxic factor (CF) in the spleen of mice. The present study was undertaken to investigate the production of nitrite (NO2-) by the spleen cells of mice in vitro and in vivo following inoculation of DV or CF. Maximum NO2- production occurred at 45 min after inoculation of 5 microg CF, both in vitro and in vivo. The NO2- was produced by macrophages and T cells and not by B cells. Pretreatment of CF with anti-CF antisera inhibited production of NO2-. DV-stimulated spleen cell culture supernatants showed peak production of CF and NO2- at 72h. In DV-infected mouse spleen, maximum NO2- production occurred at 8-11 days post-infection, which correlated with peak cytotoxic activity in the spleen. Pretreatment of spleen cells with N(G)-monomethyl L-arginine (NMMA) inhibited NO2- production. NO2- production was abrogated in a dose-dependent manner by treatment of spleen cells with Ca2+ channel blocking drug, Nifedipine. The findings demonstrate that DV-induced CF induces production of NO2- in spleen cells, probably in a Ca2+-dependent manner, and may be a mechanism of target cell killing.

Dengue virus-induced cytotoxin releases nitrite by spleen cells

Dengue type-2 virus (DV) infection in mice induces T cells to produce a cytokine, the cytotoxic factor (CF), which induces H2-A positive macrophages to produce another cytokine, cyototoxic (CF2), which amplifies its cytotoxic effects on target cells. The present study was undertaken to investigate the production of nitrite (NO2-) by the spleen cells of mice in vitro and in vivo following inoculation of CF2. Maximum NO2- production occurred at 1 hour after inoculation of 100 micrograms CF2. Pretreatment of CF2 with anti-CF2-antisera (CF2-As) inhibited the production of NO2-. Pretreatment of the spleen cells with NG-monomethyl-L-arginine (NMA) or with arginase inhibited NO2- production. The NO2- production was diminished in a dose dependent manner by treatment of spleen cells with the Ca2+ channel blocking drug, nifedipine and Zn2+ as ZnSO4. The findings of the present study thus demonstrate that CF2 induces production of NO2- in the spleen cells in a CA(2+)-dependent manner which may be a mechanism of target cell killing.

A behavioural and neurochemical study in rats of the pharmacology of loreclezole, a novel allosteric modulator of the GABAA receptor

Loreclezole is an anticonvulsant and anxiolytic compound which has been reported to potentiate GABA via a novel allosteric site on the beta-subunit of the receptor. We have now studied in rats both the in vivo and in vitro pharmacology of the compound. The dose of loreclezole required to increase by 50% the dose of intravenous pentylenetetrazol eliciting a seizure was comparable to that of barbiturates and chlormethiazole (in mg/kg): diazepam, 1.3; pentobarbitone, 16; chlormethiazole, 22; loreclezole, 25; pentobarbitone, 36. Loreclezole dose-dependently decreased locomotion (dose to decrease locomotion by 50% (in mg/kg): chlormethiazole, 9; pentobarbitone, 16; loreclezole, 25). Loreclezole, chlormethiazole and pentobarbitone all failed to displace [3H]muscimol and [3H]flunitrazepam binding from a rat cortical membrane preparation. All three compounds fully displaced [35S]TBPS binding (IC50 values: loreclezole, 4.34 +/- 0.68 microM; pentobarbitone, 37.39 +/- 3.24 microM; chlormethiazole, 82.10 +/- 8.52 microM). Addition of bicuculline (10 microM) produced a major rightward shift in the loreclezole and pentobarbitone displacement curves, increasing IC50 values for [35S]TBPS binding by 25 times (loreclezole), 6 times (pentobarbitone) and 2.7 times (chlormethiazole), suggesting a greater involvement of GABA in the interaction of loreclezole with the chloride channel than in the case of chlormethiazole. Anticonvulsant activity of the compounds did not appear to relate to [35S]TBPS binding activity. Other binding data suggested that although the evidence of others indicates that loreclezole interacts with a specific allosteric site on the beta-subunit, it nevertheless also alters the binding characteristics of other modulatory sites.

The spin trap reagent PBN attenuates degeneration of 5-HT neurones in rat brain induced by p-chloroamphetamine but not fenfluramine

Dark Agouti rats injected with either p-chloroamphetamine (PCA; 2.5 mg/kg i.p.) or fenfluramine (15 mg/kg i.p.) had substantial decreases (approximately 50%) in the concentration of 5-HT and 5-HIAA and binding of [3H]paroxetine in the cerebral cortex 7 days later. This indicates that both compounds had produced neurodegeneration of 5-HT axon terminals. Two doses of alpha-phenyl-N-tert-butyl nitrone (PBN; 150 mg/kg i.p.) 130 min apart had no effect on cortical 5-HT content or [3H]paroxetine binding. However, when PBN (150 mg/ kg) was given 10 min before and 120 min after PCA (2.5 mg/kg) it attenuated the PCA-induced neurodegeneration. In contrast, PBN was without significant effect on the fenfluramine-induced damage. Changes in rectal temperature following either the neurotoxins or neurotoxins+ PBN were no more than +/-1 degree C of saline-injected control rats. These data indicate that PCA, like MDMA, probably induces neurotoxic degeneration because of the formation of catechol or quinone metabolites and subsequent reactive tree radical formation. Such a mechanism does not appear to explain fenfluramine-induced damage to 5-HT neurones.