Biomedical subjects

K Bala

Publications and source records attributed to K Bala.

At least 19 recordsLinked to original sources

PubMed2004

Single-capillary Teorell oscillator--studies with nonelectrolytes.

It has been demonstrated that if in a Teorell oscillator, the membrane is replaced by a single capillary, the system behaves much better and becomes easily reproducible. It has also been demonstrated that oscillatory behavior in a Teorell-type setup is not limited to electrolytes; even nonelectrolytes can show oscillations. The only requirement seems to be that the nonelectrolyte should be capable of generating an electrical double layer in the capillary. This is the first report of a Teorell oscillator with a single capillary. Also, oscillations with nonelectrolytes in a Teorell-type setup have not been reported before.

Journal Article↗

PubMed2003

Phenylpropanolamine-induced intraventricular hemorrhage.

Intracranial hemorrhage is an uncommon complication of phenylpropanolamine. There is an increasing awareness of this complication in the West. However, to the best of our knowledge there have been no cases reported from India. Here we report a patient who developed Intraventricular hemorrhage following ingestion of Phenylpropanolamine, from which he made an uneventul recovery over the next two weeks.

Adult↗

PubMed2002

Effects of a potato cysteine proteinase inhibitor on midgut proteolytic enzyme activity and growth of the southern corn rootworm, Diabrotica undecimpunctata howardi (Coleoptera: Chrysomelidae).

The major proteinase activity in extracts of larval midguts from the southern corn rootworm (SCR), Diabrotica undecimpunctata howardi, was identified as a cysteine proteinase that prefers substrates containing an arginine residue in the P1 position. Gelatin-zymogram analysis of the midgut proteinases indicated that the artificial diet-fed SCR, corn root-fed SCR, and root-fed western corn rootworms (Diabrotica virgifera virgifera) possess a single major proteinase with an apparent molecular mass of 25kDa and several minor proteinases. Similar proteinase activity pH profiles were exhibited by root-fed and diet-fed rootworms with the optimal activity being slightly acidic. Rootworm larvae reared on corn roots exhibited significantly less caseinolytic activity than those reared on the artificial diet. Midgut proteolytic activity from SCR was most sensitive to inhibition by inhibitors of cysteine proteinases. Furthermore, rootworm proteinase activity was particularly sensitive to inhibition by a commercial protein preparation from potato tubers (PIN-II). One of the proteins, potato cysteine proteinase inhibitor-10', PCPI-10', obtained from PIN-II by ion-exchange chromatography, was the major source of inhibitory activity against rootworm proteinase activity. PCPI-10' and E-64 were of comparable potency as inhibitors of southern corn rootworm proteinase activity (IC(50) =31 and 35nM, respectively) and substantially more effective than chicken egg white cystatin (IC(50) =121nM). Incorporation of PCPI-10' into the diet of SCR larvae in feeding trials resulted in a significant increase in mortality and growth inhibition. We suggest that expression of inhibitors such as PCPI-10' by transgenic corn plants in the field is a potentially attractive method of host plant resistance to these Diabrotica species.

Amino Acid Sequence↗

PubMed2001

Association between ACE gene polymorphism and diabetic nephropathy in South Indian patients.

OBJECTIVE: To study the association of ACE gene polymorphism and diabetic nephropathy in South Indian subjects. SETTING: Outpatient clinic of a specialized hospital. PATIENTS: The study included 109 South Indian type 2 diabetic patients (72 males and 37 females; age 56.7 plus/minus 9.0 years, mean plus/minus SD). The patients were subdivided into two groups: nephropathic (n=86) and normoalbuminuric patients (n=23). INTERVENTIONS: Genomic DNA was isolated from the peripheral blood leukocytes. To determine the ACE genotype, genomic DNA was amplified by PCR initially using a flanking primer pair and, subsequently when necessary, with a primer pair that recognizes the insertion specific sequence for confirmation of the specificity of the amplification reactions. MAIN OUTCOME MEASURES: ACE genotype distribution in the two study groups. RESULTS: In the nephropathic patients, ID and DD genotypes were present in 52.3% and 27.9% of the patients, respectively as compared to 34.8% and 21.7% respectively in those with normoalbuminuria. The D allele was present in 80.2% of the nephropathic patients and 56.5% of the normoalbuminuric patients (chi-squared=4.28, P=0.039; odds ratio 3.12). Therefore, the higher percentage of II genotype in the normoalbuminuric group was 43.5% as compared to the 19.8% in nephropathic patients. CONCLUSIONS: This study showed a positive association between the D allele (ID and DD genotype) of the ACE polymorphism and diabetic proteinuria in South Indian type 2 diabetic patients. Our findings are in keeping with several earlier studies showing a strong association of the D allele of the ACE gene with diabetic nephropathy.

Alleles↗

PubMed1999

Bistability and Electrokinetic Oscillations.

Nonlinear dynamic behavior and electrokinetic oscillations have been investigated for the membrane systems (a) 0.1 N NaCl/KCl parallel Millipore filter parallel 0.01 N NaCl/KCl; (b) 0.1 N NaCl/KCl parallel Whatman Inorganic filter parallel 0.01 N NaCl/KCl; and (c) 0.1 N NaCl/KCl parallel silver-coated filter parallel 0.01 N NaCl/KCl, from the viewpoint of testing the theories for the phenomena and elucidating the mechanism. To achieve these objectives, studies on hydrodynamic permeability, electroosmotic permeability, bistability, and electrokinetic oscillations were undertaken. Relaxation time for buildup and decay of electroosmotic pressures was experimentally determined. Bistability was not observed showing that it is not a prerequisite for oscillations and nonlinear relations between (J(v))(Deltarho=0) and Deltaφ involving cubic or higher-order terms are necessary for bistability. The oscillations were studied at different current strengths. The period is found to be independent of current, while amplitude A is found to be linearly related to current I which is the bifurcation parameter. The bifurcation point occurs at approximately 0.4 mA. Studies have also been made with membranes of different pore size that show that amplitude increases with increase in pore size of the membranes. The validity of the two-variable model of Teorell was examined by comparing the experimental results with computer simulation based on parameters determined experimentally. Theory does not meet expectation and the results suggest that modification of theory is needed. The weakness of the theory has been critically examined. Copyright 1999 Academic Press.

Journal Article↗

PubMed1998

Relationship between biochemical and virological responses to interferon therapy in chronic hepatitis C infection. Consensus Interferon Study Group.

We have investigated the relationship between serum alanine aminotransferase (ALT) and hepatitis C virus (HCV) RNA in the assessment of responses to interferon (IFN) therapy in chronic HCV infection. Data from 704 patients with HCV infection who were randomized to receive consensus IFN-alpha (CIFN) 3 micrograms (n = 232 patients) or 9 micrograms (n = 232 patients), or IFN-alpha 2b 3 million units (MU) (n = 240 patients), were used for these analyses. All patients were treated three times weekly. Hepatitis C viral RNA (HCV RNA) was determined by quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) with a lower limit of detection of 100 copies ml-1. Of patients with normal serum ALT concentrations, 53% (120/225) had undetectable HCV RNA at the end-of-treatment period and 47% (51/109) had undetectable HCV RNA at the end of the post-treatment observation period. In contrast, of the patients with undetectable HCV RNA, 75% (120/161) and 84% (51/61) had normal serum ALT activities at the end-of-treatment and post-treatment observations periods, respectively. The majority of patients with undetectable HCV RNA had normal ALT values. In contrast, only half of the patients with normal ALT values were negative for HCV. End-of-treatment HCV RNA response also better predicted sustained virological response than did end-of-treatment ALT response.

Adult↗

PubMed1995