Awareness of post-exposure prophylaxis guidelines against occupational exposure to HIV in a Mumbai hospital.

BACKGROUND: Exposure to the human immunodeficiency virus (HIV) is a matter of concern for healthcare workers. We conducted a survey to determine the level of awareness amongst operating room personnel regarding post-exposure prophylaxis in case of needlestick injuries from confirmed or suspected cases of HIV. METHODS: A structured questionnaire was presented to 39 anaesthetists and 31 surgical residents. Questions were related to identification of high risk fluids, risk of transmission, drugs, costs and procedure to be adopted for post-exposure prophylaxis. RESULTS: Fourteen respondents (20%) were aware of the true risk of transmission. About one-third identified all high risk fluids correctly. Fifty-five respondents (78%) correctly stated that washing the site with soap and water was the initial measure, but less than a third knew whom to contact immediately after a needlestick injury. Though 45 respondents (64%) correctly stated that prophylaxis should be initiated within 1 hour of injury, none knew exactly which drugs were to be used. Thirty respondents (42%) were aware of the use of zidovudine but none were aware of the second or third drugs used for post-exposure prophylaxis. Only 4 respondents (6%) knew the correct duration of post-exposure prophylaxis. Five respondents (7%) knew that the drugs were available in medical stores and 7 knew the approximate cost of therapy. CONCLUSION: There is surprisingly poor knowledge of post-exposure prophylaxis against HIV. Ongoing awareness and training programmes are necessary to improve the same.

Cardiomediastinal tamponade and shock following three-stage transthoracic oesophagectomy.

Massive gastric tube dilatation causing cardiomediastinal tamponade is an unusual cause of obstructive shock after transthoracic oesophagectomy. A 55-year-old female was operated for total transthoracic oesophagectomy. Twelve hours after the surgery, she developed hypotension and raised central venous pressure unresponsive to fluid infusion and ionotropes. X-ray chest showed a massively dilated stomach, which was causing intrathoracic tamponade. Suction applied to the nasogastric tube led to aspiration of 150-200 ml of fluid and a large volume of air, which led to resolution of the haemodynamic instability. A simple manoeuvre like nasogastric suction in postoperative case of oesophagectomy can serve as a diagnostic as well as therapeutic tool. It must be performed before resorting to invasive and expensive examination or intervention.

Interactions of chromomycin A3 and mithramycin with the sequence d(TAGCTAGCTA)2.

Anti-cancer antibiotics, chromomycin A3 (CHR) and mithramycin (MTR) inhibit DNA directed RNA synthesis in vivo by binding reversibly to template DNA in the minor groove with GC base specificity, in the presence of divalent cations like Mg2+. Under physiological conditions, (drug)2Mg2+ complexes formed by the antibiotics are the potential DNA binding ligands. Structures of CHR and MTR differ in their saccharide residues. Scrutiny of the DNA binding properties reveal significant differences in their sequence selectivity, orientation and stoichiometry of binding. Here, we have analyzed binding and thermodynamic parameters for the interaction of the antibiotics with a model oligonucleotide sequence, d(TAGCTAGCTA)2 to understand the role of sugars. The oligomer contains two potential binding sites (GpC) for the ligands. The study illustrates that the drugs bind differently to the sequence. (MTR)2Mg2+ binds to both sites whereas (CHR)2Mg2+ binds to a single site. UV melting profiles for the decanucleotide saturated with the ligands show that MTR bound oligomer is highly stabilized and melts symmetrically. In contrast, with CHR, loss of symmetry in the oligomer following its association with a single (CHR)2Mg2+ complex molecule leads to a biphasic melting curve. Results have been interpreted in the light of saccharide dependent differences in ligand flexibility between the two antibiotics.

Effect of myo-inositol(1,4,5)trisphosphate on the hydrolysis of phytic acid by phytase.

Phytase is a monomeric enzyme of molecular mass 160 kDa which catalyzes the hydrolysis of phytic acid (D-myo inositol hexakisphosphate, InsP6) in a stepwise manner to myo-inositol. The enzyme-InsPn (n = 1-6) interaction at the catalytic site has a dissociation constant in the micro molar range. There also exists in the enzyme, a non-catalytic site specific for InsP3 with dissociation constant in the nano molar range. We have probed the effect of the high affinity InsP3 binding on the dissociation constant (Kd) of the phytase-InsP6 interaction and the kinetics of hydrolysis. These studies demonstrate the effect exerted by the high affinity InsP3 binding on the catalytic site of the enzyme.

Probing the nucleotide binding sites in T7 RNA polymerase using cibacron blue.

T7 RNA polymerase (T7 RNAP) is an enzyme that utilizes ribonucleotides to synthesize the nascent RNA chain in a template-dependent manner. In this work we have studied the interaction of T7 RNAP with cibacron blue, an anthraquinone monochlorotriazine dye, and its effect on the function of the enzyme. T7 RNAP binds to the dye in a bi-phasic manner. The first phase of the binding is characterized by a high affinity (Kd in the nanomolar range) and reversible inactivation of the enzyme. The second binding site is the common substrate binding site. The association of the dye with T7 RNAP is a good model to understand the physiological significance of a high affinity binding of the initiating nucleotide, GTP, earlier reported from our laboratory. The results will be discussed to understand the role of the high affinity GTP binding.

Interaction of mithramycin with chromatin.

Mithramycin (MTR) is an anti-cancer antibiotic that blocks the macromolecular biosynthesis via reversible interaction with DNA template in the presence of bivalent metal ion such as Mg2+. In absence of DNA, mithramycin forms two types of complexes with Mg2+, complex I (with 1:1 stoichiometry in terms of MTR: Mg2+) and complex II (with 1:2 stoichiometry in terms of MTR: Mg2+). In an eukaryotic system, the drug would interact with chromatin, a protein-DNA complex. We have employed the spectroscopic techniques such as absorption and fluorescence to study the interaction of MTR: Mg2+ complexes with rat liver chromatin. In this report, we have shown that the two types of ligands have different binding potentials with the same chromatin. This supports our proposition that complexes I and II, are different molecular species. We have also shown that the histone protein(s) reduce the binding potential and the number of available sites for both ligands.

Mesangial proliferative glomerulonephritis in chronic obstructive pulmonary disease.

Ten patients of chronic obstructive pulmonary disease were studied for changes in ultrastructure of the glomeruli, serum immunoglobulin and complement levels. The glomeruli showed proliferation in the mesangium in 90% patients and electron dense deposits in the mesangium in 30% patients. IgA and IgG were usually elevated whereas complements were usually depressed in most of these patients. It is suggested that repeated respiratory infections in these subjects may be responsible for mesangioproliferative type of glomerulonephritis, high IgA and IgG levels. The complements are activated and they take part in immune complex formation getting deposited in mesangium.

Chemical modification of 3-HBA-6-hydroxylase by phenylglyoxal: kinetic and physicochemical studies on the modified enzyme.

The inactivation of 3-HBA-6-hydroxylase isolated from Micrococcus species by phenylglyoxal and protection offered by 3-HBA against inactivation indicate the presence of arginine residue at or near the substrate binding site. The loss of enzyme activity was time and concentration dependent and displayed pseudo-first order kinetics. A 'n' value of 0.9 was obtained thus suggesting the modification of a single arginine residue per active site which led to the loss of enzyme activity. The enzyme activity could be restored by extensive dialysis at neutral pH. Quenching of the intrinsic fluorescence and reduction in the ellipticity value at 280 nm in the near-UV CD spectrum of the enzyme was noticed after its treatment with phenylglyoxal. These observations probably imply distinct perturbations in the environment of adjacent aromatic amino acid residues such as tryptophan as a consequence of arginine modification.

Electrocardiographic manifestations of healthy residents of a tribal Himalayan village.

Electrocardiograms of 984 healthy subjects residing in village Kalpa at the height of 9000 feet above sea level were studied. Right ventricular hypertrophy (RVH) was observed in 9 (0.914%) subjects. Electrocardiographic evidence of ischaemic heart disease was found in 6 (0.609%) subjects.

Effective reduction of LDL cholesterol by indigenous plant product.

A herbal powder containing guar gum, methi, tundika and meshasringi was administered to 30 control and 30 type 2 (non-insulin dependent) diabetes mellitus patients for a month. Total serum cholesterol and its fractions eg, high density lipoprotein, low density lipoproteins, very low density lipoproteins and serum triglyceride were determined before and after the trial period. Total and low density lipoprotein (LDL) cholesterols were reduced significantly after the therapy. There were no significant changes in high density lipoproteins (HDL), very low density lipoproteins (VLDL) or triglyceride levels. Side-effects eg, mild flatulence and looseness of bowel were noticed in less than 40% cases.

Control of hyperglycaemia and hyperlipidaemia by plant product.

A herbal powder consisting of Guargum, Methi, Tundika and Meshasringi was administered to thirty control and thirty NIDDM patients twice daily before principal meals for four weeks. Oral GTT showed improvement in both control and patient groups. Serum total and LDL cholesterol also fell significantly in both the groups after the trial period. Test meal of the herbal powder with D-Xylose excretion was otherwise normal. Follow up for upto two years did not reveal any long term side effect of the powder. This powder, therefore, can be effectively used to reduce postprandial blood glucose and LDL cholesterol in NIDDM patients as a long term measure.

Electrocardiographic changes during upper gastrointestinal endoscopy in ambient hypoxia.

Electrocardiographic (ECG) changes were studied in 120 consecutive subjects during and after upper GI endoscopy done in ambient hypoxia (PO2-120 mmHg) at Shimla (2200 m). No premedication was given to any of the subjects. There were 75 men and 44 women. Fifty three subjects were aged 40 years or below (Group I) and 67 subjects were above 40 (Group II). There were 29 subjects with and 91 subjects without cardiac diseases. Increase in heart rate was seen in 96.6% of subjects. Maximum rise in heart rate was found in cardiac patients. ST depression was seen in 14.2%, T wave inversion in 13.3%, supraventricular tachycardia in 5.8% and ventricular ectopics in 1.6%. ST depression was more frequent in cardiac than in non cardiac patients (P less than 0.001) and T wave inversion was more frequent in women than in men (P less than 0.001). All the changes reverted to normal within 10 minutes. ECG changes notwithstanding, upper GI endoscopy without premedication in the presence of ambient hypoxia is a safe procedure.

Alterations in immunoglobulin & complement levels in chronic obstructive pulmonary disease.

Thirty patients of chronic obstructive pulmonary disease (COPD; all smokers) and an equal number of controls (15 smokers) were studied. The COPD patients were further divided into group A (predominantly emphysema) and group B (predominantly bronchitis) of 15 patients each. Serum and sputum IgG, IgA and IgM and serum C3 and C4 were estimated. IgG, IgA, IgM and C3 and C4 were similar in smoker and non-smoker controls. Mean (+/- SD) serum IgG (IU/ml) was significantly higher in COPD patients (207.78 +/- 62.73) than in control (177.25 +/- 43.5; P less than 0.05), serum IgA (IU/ml) was also significantly higher in COPD (205.04 +/- 46.56) than in control (108.21 +/- 33.3; P less than 0.01). IgM was similar in the 2 groups. Sputum IgA (IU/ml) was higher in COPD (4.68 +/- 3.51) than in control (2.25 +/- 1.03; P less than 0.05). IgG and IgM were similar in the 2 groups. Both serum C3 (IU) and C4 (IU) were lower in COPD patients (C3 = 95.9 +/- 33.11, C4 = 113.6 +/- 62.4) than in control (C3 = 167.3 +/- 25.42, C4 = 205 +/- 76.5; P less than 0.05). Serum IgA in type B COPD (212.25 +/- 50.06) was higher than in type A (197.52 +/- 43.3; P less than 0.05) IgG and IgM were similar in these 2 groups. In COPD patients, immunoglobulins were either normal or higher indicating that deficiency of immunoglobulin is not a predisposing factor in development of COPD. Similar immunoglobulin values in smoker and nonsmoker controls indicated that smoking was not the cause of rise of immunoglobulins in COPD.(ABSTRACT TRUNCATED AT 250 WORDS)

Comparative clinical evaluation of chandonium iodide and pancuronium bromide as muscle relaxant.

Chandonium iodide, a synthetic non-depolarising neuromuscular blocking agent and pancuronium bromide were clinically compared as muscle relaxants in 62 patients undergoing elective surgery. Anaesthesia was induced by thiopentone sodium and maintained by oxygen and nitrous oxide. Assessment of efficacy of both the muscle relaxants was graded taking into consideration intubating condition and muscular relaxation during surgery. Tolerability was assessed by noting the changes in heart rate, blood pressure and biochemical estimations. Efficacy of chandonium iodide in the dose of 0.15 to 0.18 mg/kg was comparable to that of 0.08 to 0.1 mg/kg of pancuronium bromide. Both the drugs were well tolerated.