Serodiagnosis of gut tuberculosis

The efficacy of enzyme-linked immunosorbent assay (ELISA) in the diagnosis of gut tuberculosis was evaluated. The study included 95 patients with gut tuberculosis, 40 with pulmonary tuberculosis, 25 with non-tubercular intestinal diseases and 40 healthy controls. Mantoux response and antibody titre against PPD using ELISA were studied. The ELISA sensitivity in gut tuberculosis was 80% and in pulmonary tuberculosis 90%. It was also positive in 12% of patients with non-tubercular intestinal diseases and 5% of healthy controls. The sensitivity of Mantoux test in gut (77%) and pulmonary (84%) tuberculosis was comparable to that of ELISA. However, Mantoux test lacked diagnostic significance due to high positivity in non-tubercular disease patients (55%) and healthy controls (56%), whereas ELISA was highly specific (93%) for the diagnosis of gut tuberculosis.

Estimation of 24 hour protein excretion from single random urine specimen

The product of protein/creatinine ratio (in a random urine specimen) and estimated daily urinary creatinine excretion were evaluated as a function of 24 h urinary protein excretion in 40 patients with pathology proteinuria having varying grades of renal function. An excellent correlation was found between the results obtained by this method and those from the standard 24 h urine collection method in healthy controls (r = 0.99) and in patients with normal (r = 0.88) or mild to moderately impaired renal function (r = 0.99). However, this method did not give a good measure of quantitative proteinuria in patients with advanced renal failure (r = 0.56), possibly due to decreased urinary excretion of creatinine in patients with advanced renal failure as compared to the estimated value. The product of protein/creatinine ratio and estimated daily urinary creatinine excretion thus gave a quick and alternate reliable method of estimating 24 h proteinuria in patients having normal or mild to moderately impaired renal function. However, this method is not suitable for patients with advanced renal failure.

Vasculitis--a complication of hypothyroidism

A case of hypothyroidism presenting with cutaneous vasculitis is described. Apart from typical findings of hypothyroidism, the patient had hypertension (HT). With thyroxine replacement therapy patient showed an improvement in hypothyroidism, HT and cutaneous vasculitis.

Stimulation of low density lipoprotein receptor activity in liver membrane of guggulsterone treated rats

Chronic feeding of guggulsterone to rats showed hypolipidaemic activity in blood serum and liver membrane lipids. The decrease in serum cholesterol is associated with enhanced uptake of LDL by the liver through receptor mediated endocytosis, located on the surface of the cell membrane. In the present communication it has been shown that membranes prepared from liver of guggulsterone treated rats exhibit up to 87% increase in binding sites for human 125I-LDL. Significant decrease in lipid levels of serum as well as of membrane were observed. Lipid lowering activity of the drug in relation to LDL catabolism and other possible mechanisms have been explained.

Hormonotoxins. Effects of modifying the gonadotropin alpha-subunit on the generation of lutropin-toxin conjugates

On the basis of the observation that in the hormonotoxin oLH-gelonin conjugation of the toxin occurs via the alpha-subunit of lutropin, an attempt was made to develop a general method for generation of similar hybrid proteins involving other glycoprotein hormones. In this approach sites suitable for conjugation would be first introduced into the alpha-subunit, hybridized with any native hormone specific beta-subunit of choice (LH-beta, FSH-beta, TSH-beta) following which the toxic component gelonin would be added on in the form of gelonin-S-S-alpha---beta complex. Thus, thiolated lutropin alpha-subunit recombined well with free lutropin beta-subunit, yielding a hybrid which was active in terms of receptor binding, immunoreactivity, and steroidogenic properties. However, subsequent conjugation with thiolated gelonin, a ribosome inactivating protein, resulted in dissociation of beta-subunit from its non-covalent union with the thiolated alpha-subunit. It is concluded that the addition of positively charged gelonin at particular sites on the alpha-subunit led to the destabilization of the lutropin quaternary structure.

Molecular epidemiology of human rotavirus infections in Chandigarh (India)

Molecular epidemiology of rotavirus infections was studied in children with acute gastroenteritis attending the Nehru Hospital, Chandigarh. A total of 87 stool samples were studied for RNA migration pattern by polyacrylamide gel electropherosis. Only 33 strains could be electropherotyped and two different RNA types 'Short' and 'Long' were observed. Fifteen had a Short RNA pattern and 18 had a Long RNA pattern. There were no intergenomic variations between the Short or Long RNA types. On analysis of subgroup specificity by ELISA using monoclonal antibodies, all Long strains belonged to subgroup 2 and all Short strains to subgroup 1. Our results show that only two electropherotypes were prevalent in the area studied and during a particular peak of infection, only one electropherotype was predominant.

Hepatic low density lipoprotein receptor binding and lipid profile in Mastomys natalensis during Plasmodium berghei infection

Plasmodium berghei infection to Mastomys natalensis showed hyper beta-lipoproteinemia. The increase in serum cholesterol is associated with decreased uptake of low density lipoprotein (LDL) by the liver through receptor mediated endocytosis. The membranes prepared from infected M. natalensis exhibit up to 50% decline in high affinity binding sites for human 125I-LDL. Significant increases in serum lipids, cholesterol, triglyceride and lipid peroxide (LPO) contents of liver membrane were observed. Effects of lipid constituents and LPO content of liver membrane in relation to LDL catabolism and other possible mechanisms have been explained.

Hormonotoxins: conjugation of human choriogonadotropin with the ribosome inactivating protein gelonin and comparison with a lutropin conjugate

The properties of two hormonotoxins, human choriogonadotropin and ovine pituitary lutropin, each conjugated to the ribosome inactivating protein gelonin, have been compared. In both cases the linkage is effected through a disulfide bond provided by the cross-linker N-succinimidyl-3-(2-pyridyldithio)propionate. In each conjugate the hormone and toxin were calculated to be present in a ratio of 1:1. Immunological reactivity, receptor binding activity and steroidogenic activity of the hormonotoxins in radioimmunoassay or in membranes or cells containing LH receptors were reduced but not abolished in comparison with the thiolated hormones. Purified hormonotoxins were characterized by immunoassays specific for both interaction components, viz. the hormone (LH/hCG) and gelonin. Binding of the toxic component (gelonin) to the mouse Leydig tumour cells (MA-10 cells) was shown to occur via the hormone part of the hormonotoxins. This was effectively competed by the native hormone but not free gelonin. Both hormonotoxins were cytotoxic to MA-10 cells as protein synthesis was inhibited in their presence. This was associated with destruction of tumor cells in culture.

Effects of thiolation on the immunoreactivity of the ribosome-inactivating protein gelonin

Gelonin purified from the seeds of Gelonium multiflorum using cation-exchange and gel-filtration chromatography was characterized for its purity, homogeneity and Mr by reverse-phase h.p.l.c. and SDS/polyacrylamide-gel electrophoresis analysis and judged to be 98% pure. As the cross-linking agent N-succinimidyl-3-(2-pyridyldithio)propionate (SPDP) has been used for linking gelonin via its epsilon-NH2 group to its carrier antibodies or hormones for immunotoxin or hormonotoxin respectively, an attempt was made to study the effect of this modification of gelonin on its immunoreactivity. A radioimmunoassay was developed for this purpose. By sequential modification, four categories of amino group modifications on immunoreactivity were observed. Even one or two modifications, representing one-twentieth to one-tenth of available epsilon-NH2 groups in the protein caused about 75% loss in immunoreactivity, with additional reactions contributing to further deteriorations. By using a gelonin radioimmunoassay, the immunoreactivity of gelonin in three hormonotoxins was determined with gelonin and modified gelonin as standards. The gelonin equivalent in our hormonotoxins was in agreement with the values determined by spectrophotometric and gel-electrophoresis methods. As the immunoreactivity of gelonin-SPDP was not further altered after conjugation to its carrier protein ovine lutropin, a specific radioimmunoassay of gelonin could be used to evaluate the molar ratio of the conjugates prepared by using SPDP as cross-linker and gelonin-SPDP as a standard.

Comparative study of capillary and arterial, blood gas values in plastic and glass syringes at various intervals in normal and asthmatic subjects

Fifty-six normal healthy subjects and forty-four patients with bronchial asthma were subjected to capillary and arterial blood gas analysis. Arterial blood values were measured immediately and at two and four hours interval after storing the samples between 0-4 degrees C using glass and plastic syringes. It was observed that PO2 of arterial blood was significantly higher (P less than 0.001) than capillary PO2 values, while material of syringe and time interval of analysis did not make any significant alteration. PCO2 and pH values in arterial samples at various intervals and in different syringes were comparable in normal as well as in asthmatic subjects.

Delta hepatitis infection in north India. A preliminary report

There is a paucity of data on occurrence of delta hepatitis in India. We here present our preliminary data showing that delta coinfection and superinfection occur quite frequently in our set up. The coinfection rate was found to be 15% and superinfection rate 26.6% in the initial screening of 69 patients of acute and chronic liver disease.

Effects of thiolation of amino groups of ovine lutropin on immunoreactivity, receptor binding and bioactivity

We have studied the reaction of epsilon-amino groups of ovine lutropin with N-succinimidyl-3-(2-pyridyl-dithio) propionate (SPDP) and observed that modification of up to 1/3 of all available residues primarily occurs in the alpha-subunit. The 12 lysines available could be classified into three categories, as highly, moderately and less accessible. The three lysine residues of the hormone that appeared to resist modification may be in the intersubunit contact region. Sequential modifications of lysine residue in the alpha-subunit led to progressive reduction in receptor binding and immunological activities, but not in full steroidogenic potential. The discrepancy between reduced receptor binding and full steroidogenic activity may be related to the introduction of addition hydrophobicity to the ovine lutropin molecule. Total inactivation resulted only when the majority (9/12) of available amino groups were altered by this reaction. Thus, our study shows that by a limited reaction it is possible to create conjugation site(s) in ovine lutropin with significant retention of hormonal activity.

Fulminant viral hepatitis: Indian experience

Thirty-six patients with fulminant viral hepatitis were studied. Enzyme immunoassay was used to detect the presence of HBsAg, IgM anti-HBc, and IgM anti-HAV. Non-A, non-B virus was the most common aetiological agent (61.1%) followed by hepatitis B virus (HBV; 30.6%) and hepatitis A virus (8.3%). Presence of IgM anti-HBc confirmed the diagnosis of HBV infection in three cases who were negative for HBsAg. Similarly, in one case who was positive for HBsAg, absence of IgM anti-HBc suggested superinfection with some other agent. Survival was significantly higher (P less than 0.01) in the hepatitis A virus (HAV) group (66.6%) compared with non-A, non-B (31.2%) and HBV groups (27.3%). Fever at the onset of illness was seen in all patients with HAV, 54.5% of patients with HBV and 38.88% of patients with non-A, non-B infection (P less than 0.01). The median time interval between the first symptom and the onset of encephalopathy was 16, 13 and 8 days in HAV, HBV and non-A, non-B groups, respectively, but this difference was statistically not significant (P greater than 0.05).

Hormonotoxins. Preparation and characterization of ovine luteinizing hormone-gelonin conjugate

With the aim of targeting toxins to selected cells in the gonad, we have prepared conjugates of ovine luteinizing hormone (oLH) with a single chain ribosome-inactivating protein called gelonin. The two proteins were thiolated by using N-succinimidyl-3-(2-pyridyldithio)propionate and subsequently reacted under appropriate conditions to form oLH-S-S-gelonin complex. A complete biochemical analysis of thiolated oLH and oLH-gelonin conjugates has been performed. The linkage of the hormone to the toxin probably occurred through a single amino group in the alpha-subunit, with the beta-subunit remaining free. Modification of a single amino group on the alpha-subunit reduced receptor binding and immunological reactivity of the thiolated oLH, but subsequent complexing with the toxin-gelonin did not seriously compromise these activities. oLH and gelonin were calculated to be present in a 1:1 ratio in the hormonotoxin preparation. The conjugate retained significant steroidogenic activity in rat granulosa cells. Upon reaction with mouse tumor Leydig cells (MA-10 cells), the toxin component of the complex became internalized to a sufficient degree to effectively inhibit protein synthesis. The studies provide a rational basis for the design and study of large hormonotoxins.

Clinical and epidemiological features of acute gastroenteritis associated with human rotavirus subgroups 1 and 2 in northern India

Rotavirus was detected in 111 (15.9%) of 694 children who presented to our hospital with acute diarrhoea over a period of 45 months (1982-1985). Subgrouping for rotavirus was done on 87 children by ELISA using specific monoclonal antibodies to find out any differences in the epidemiology and clinical profile of the two subgroups. Twenty six (29.9%) were found to belong to subgroup 1 and 61 (70.1%) to subgroup 2. Diarrhoea, vomiting and fever were present in both the subgroups in the same frequency. However, the severity of diarrhoea was more in children having subgroup 2 infection. Rotavirus infection showed two peaks, one during the early months of summer and the other during the early months of winter of each year. During most of the study period, infection was predominantly with subgroup 2, except for a few months in 1983 and 1985 when a majority of children had infection with subgroup 1.