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Biomedical subjects

J Abraham

Publications and source records attributed to J Abraham.

At least 73 records · Page 4Linked to original sources
PubMed1990

Avoiding empiric therapy for brain masses in Indian patients using CT-guided stereotaxy.

Empiric therapy, especially antituberculous therapy, is frequently given to Indian patients with brain masses. This report documents our experience in avoiding such therapy using CT-guided stereotaxy. Out of 101 procedures done on 99 patients with brain masses, 80 were done to obtain a histological diagnosis and 21 for therapeutic purposes. There was no mortality and 2% morbidity. A positive diagnosis was obtained in 94% (75/80) of patients undergoing a biopsy. Diagnosis of tuberculous lesions was based mainly on the presence of acid-fast bacilli in the biopsy specimen or pus. In six patients the radiological diagnosis was wrong and in one the diagnosis was not certain. Inappropriate therapy was given to three patients, on the basis of a CT or MRI scan, before a biopsy was done. It is essential that a histological diagnosis be obtained in all patients with brain masses and there is no role for empirical therapy except in isolated cases.

Adolescent↗
PubMed1990

Brain abscess and congenital heart disease.

One hundred and thirty-three cases of brain abscess over a period of 20 years (1967-1986) were reviewed and 25 (18.7%) of these were associated with congenital heart disease (CHD). Headache was the predominant clinical feature and anaerobic streptococci were the commonest pathogen isolated. Craniotomy and excision of the abscess and burrhole aspiration were the mainstay of treatment together with appropriate antibiotic therapy. The importance of early diagnosis and treatment had been highlighted and the relative merits of the two methods of treatment were discussed.

Adolescent↗
PubMed1989

Colorimetric assay for free and bound L-fucose.

A novel, rapid, and reliable colorimetric method for measuring L-fucose has been developed. This method utilizes NADH formed from the interaction of L-fucose with fucose dehydrogenase and NAD to generate color in a reaction involving CuSO4 and neocuproine. NADH reduces Cu2+ to Cu1+ and the latter interacts with neocuproine to yield a complex with a maximal absorption at 455 nm. The reaction of NADH with copper-neocuproine is immediate and under the conditions of the assay the color formed remains stable for at least 2 h. When the assay is used to determine levels of L-fucose, the absorbance is found to be linearly proportional to exogenously added fucose concentrations from 16 to 179 nmol with resulting molar extinction coefficient of 13,660. Using this procedure, L-fucose released by acid hydrolysis from porcine submaxillary mucin, and by alpha-L-fucosidase from p-nitrophenyl-alpha-L-fucopyranoside, was quantitated.

Animals↗
PubMed1989

Non-traumatic cerebrospinal fluid rhinorrhea: the "normal pressure leaks".

Non-traumatic cerebrospinal fluid (CSF) rhinorrhea is an uncommon condition. 15 patients with non-traumatic CSF rhinorrhea having "normal pressure leaks" are presented. Metrizamide CT cisternography failed to reveal the site of the fistula in 3 patients. 11 of the 15 patients underwent surgery for closure of the fistulous communication. In 8 of them the fistula was in the anterior fossa, in one it was in the sellar floor and in two the fistula site was not seen either radiologically or at surgery. In all except the one patient with sellar floor defect an intracranial approach was used. 12 patients have been followed up for 6 months to 9 years and 10 (83%) have been cured of their rhinorrhea. The intracranial approach is preferred to an extracranial approach in the repair of anterior fossa fistulae. Conservative treatment may be effective in selected patients.

Adult↗
PubMed1989

Coagglutination (COA) test for the rapid diagnosis of cryptococcal meningitis.

Cryptococcus coagglutination (COA) test reagent was prepared locally and showed no cross reactions with different species of bacteria or yeasts or with 75 control sera including 25 that gave positive results for RA factor. We used the COA test to detect cryptococcus antigen in the CSF and we could confirm the diagnosis of 11 out of 115 suspected cases of fungal meningitis; the titre varied from 4 to 128. A four-fold rise in titre confirmed the diagnostic value and a steady fall in titre in three patients on therapy indicated the prognostic value of the test. The earliest confirmation was in a renal transplant patient on the eighth day after onset of symptoms. The COA test was negative with the CSF of 118 patients with chronic meningitis. Cryptococcal colony forming units (cfu) in CSF varied from 100 to greater than 100,000/ml and correlated well with microscopy and with the COA antigen titre in CSF. Four out of the 11 patients who had cryptococcaemia, had 50,000-100,000 cfu/ml in the CSF. Cryptococcus antigen was detected by COA in the serum of all 11 patients, even in those with only 100 cfu/ml in CSF. In the three post-renal transplant patients, who were being monitored regularly, the diagnosis was made early and all three recovered on antifungal therapy with no relapse to date (1-2 years). All the others, including the two primary CNS infections, succumbed to the disease because they presented late for diagnosis and therapy. The cryptococcus COA test is a simple and specific test that can be used as a rapid test to confirm early diagnosis and permit prompt therapy, which should improve the prognosis in CNS and other forms of systemic cryptococcosis. Moreover, it is reproducible and cost-effective, particularly in countries where the latex and other expensive test reagents are not generally available.

Adolescent↗
PubMed1989

The fate of gamma L crystallins in rat lens during diabetic cataractogenesis as determined by a monoclonal antibody.

We developed a monoclonal antibody against HPLC purified rat lens gamma L crystallins. This antibody was specific to both the polypeptides (19,000 and 21,000 daltons) which constituted the HPLC gamma L peak. Least reactivity was shown against gamma H (24,000 daltons). This antibody was used as a probe to detect the presence of and quantitate gamma L crystallins in lens soluble, insoluble and urea-insoluble fractions during diabetes. Utilizing a direct binding immunoassay (ELISA) we calculated the absolute quantities of gamma L crystallins present in these fractions. Our results show, in normal animals there was a minimal change in total quantities of gamma L crystallins in soluble fraction from 1 month to 5 months of age, but a slow accumulation of these crystallins in insoluble and urea-insoluble fractions was seen during the same period. Diabetes resulted in a depletion of gamma L crystallins from the soluble fraction, both in terms of relative proportion and absolute quantities. In insoluble and urea-insoluble fractions the relative proportions of these crystallins were increased dramatically up until 60 days followed by a decrease during 90-120 days of diabetes, whereas, the absolute quantities remained more or less steady after reaching the maximum on 60 days. Although the relative proportions of gamma L crystallins in the insoluble fraction seem to be less when compared to urea-insoluble fraction, the total quantity of these crystallins was much higher due to abundance of this fraction.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

Posterior fossa abscesses. A review of 33 cases.

Thirty three cases of posterior fossa abscesses seen over a period of 20 years are reviewed. 84.8% of these were secondary to otogenic disease. Two abscesses were due to tuberculosis and one due to actinomycotic infection. The overall mortality was 12.1%. Total excision of the abscess with appropriate antibiotic therapy was associated with an operative mortality of 3.4%.

Brain Abscess↗
PubMed1989

Changes in noradrenaline and histamine in monkey spinal cords traumatised by weight drop, compression and subsequent decompression.

Levels of noradrenaline (NA) and histamine (H) in the spinal cord of monkeys at 8, 24 and 48 hr following 200 g/cm contusion injury, 50 g of compression injury at 8 hr and decompression for 16 and 40 hr following 8 hr of compression were studied in the traumatised and in an adjacent non-traumatised segment. The NA level doubled in the traumatised and non-traumatised segments at 8 hr contusion injury followed by a slow decline to control values at 24 and 48 hr of contusion injury. There was no change in NA content of the spinal cord segments at 8 hr of compression injury. Decompression for 16 hr following 8 hr of compression increased NA content of the traumatised segment. H levels decreased in the traumatised and non-traumatised segments at 24 and 48 hr of contusion injury. Compression for 8 hr elevated H in the traumatised and non-traumatised segments. On decompression H level was further increased in the traumatised segment.

Animals↗
PubMed1988

A colorimetric procedure for measuring beta-lactamase activity.

The enzymatic hydrolysis of benzylpenicillin was measured by a novel colorimetric procedure. The penicilloic acid generated from the hydrolysis of penicillin was reacted with CuSO4 and neocuproine to form a colored complex having a maximal absorption at 454.5 nm. A plot of absorbance versus beta-lactamase activity yielded a straight line from 1 to 5 mU of enzyme. Using TEM-1 as the model beta-lactamase, a Km of 46 microM was observed with benzylpenicillin serving as the substrate. When the assay was used to determine levels of benzylpenicillin, the absorbance was found to be linearly proportional to exogenously added penicillin from 2.8 to 88 microM. This procedure is simple to use and can be employed to measure the hydrolysis of other beta-lactam antibiotics.

Anti-Bacterial Agents↗
PubMed1988

Free fatty acids, lipid peroxidation, and lysosomal enzymes in experimental focal cerebral ischemia in primates: loss of lysosomal latency by lipid peroxidation.

Experimental focal cerebral ischemia was produced in monkeys (Macaca radiata) by occlusion of the right middle cerebral artery (MCA). The release of the lysosomal glycosidases, beta-D-hexosaminidase, alpha-L-fucosidase and alpha-D-mannosidase into the soluble fraction in the right basal ganglia of the experimental animals was measured at different periods from 30 min to 12 hr after occlusion and compared with the corresponding sham operated control animals. There was a significant increase in the released lysosomal enzymes in the MCA occluded animals at all periods and particularly at 4 hr after occlusion. The CSF from the experimental animals also showed elevated levels of hexosaminidase and fucosidase. The free fatty acids (FFA) measured in the basal ganglia at 30 min and 2 hr after occlusion showed a 100 fold increase in the experimental animals. The predominant fatty acid released was linoleic acid (18:2) followed by arachidonic acid (20:4). Lipid peroxidation in the basal ganglia measured by the thiobarbituric acid (TBA) reaction in the presence or absence of ascorbic acid also showed a significant increase in the experimental animals at all periods with a maximum at 30 min to 2 hr after occlusion. In order to assess whether lipid peroxidation causes damage to the lysosomes and release of the enzymes, a lysosome enriched P2 fraction from the normal monkey basal ganglia was prepared and the effect of peroxidation studied. Maximum peroxidation in the P2 fraction was observed in the presence of arachidonic acid, ascorbic acid and Fe2+.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1987

Generation of human B-cell hybridomas secreting monoclonal anti-myelin-associated glycoprotein antibodies from a patient with neuropathy.

Human hybridomas that secrete monoclonal IgM anti-myelin-associated glycoprotein antibodies were generated by fusion with cells from a patient with peripheral neuropathy and IgM monoclonal gammopathy. Karyotypic analysis of the hybridoma cells revealed no chromosomal abnormalities. The cells were positive for cell-surface idiotype HLA-DR and the plasma cell antigen PCA-1, and negative for the B-cell determinant B4 and for Leu-1, which has been postulated to distinguish a subpopulation of B cells that secrete IgM with autoantibody activity.

Antibodies, Anti-Idiotypic↗
PubMed1987

Omento-myelo-synangiosis in the management of chronic traumatic paraplegia: case report.

A case of traumatic paraplegia, with almost complete motor and sensory loss up to the umbilicus, who had an operation for post traumatic arachnoiditis and diagnosed as having recurrence of arachnoiditis and traumatic syringomyelia and treated by a pedicled omental onlay graft to the spinal cord, is described. The patient made a remarkable recovery and 1 year after surgery he continues to maintain excellent progress. He is now able to walk with support and is completely independent. It is suggested that chronic paraplegics should be assessed for possible arachnoiditis and traumatic syringomyelia and if detected an omental transposition be considered as one means of increasing rehabilitation potential.

Adult↗
PubMed1987

Changes in the content of dopamine and its metabolites in the basal ganglia following right middle cerebral artery occlusion and reflow in monkeys.

Focal ischaemia was produced experimentally in Macaca radiata monkeys by occlusion of middle cerebral artery (MCA). There was a lowering of the dopamine (DA) content of basal ganglia after 4 and 12 h of occlusion. DA content was restored to normal in basal ganglia after restoration of blood flow. With the progress of time the DA content was increased above that of sham controls. Changes were also observed in the non-occluded left basal ganglia. The homovanillic acid (HVA) content was decreased significantly at 12 h after occlusion. After the onset of reflow, the HVA content of the right basal ganglia was higher than that of sham controls. The 3,4 dihydroxyphenylacetic acid (DOPAC) content of right basal ganglia was significantly decreased after 12 h occlusion. Reflow restored the level of DOPAC to normal within 1 h after removal of clip. Discrete changes were also observed in the left basal ganglia at some of the time intervals.

3,4-Dihydroxyphenylacetic Acid↗