Search PubMed⌕ Search

Biomedical subjects

A Goyal

Publications and source records attributed to A Goyal.

At least 127 records · Page 7Linked to original sources
PubMed1991

Unsuspected mitral stenosis.

PURPOSE AND PATIENTS AND METHODS: We observed a series of patients in whom the diagnosis of mitral stenosis was first discovered in the echocardiography laboratory. Because of this experience, we examined the records of 152 patients with echocardiographic evidence of rheumatic mitral stenosis to determine the clinical characteristics and course of patients with unsuspected mitral stenosis as well as those factors that may have obscured the diagnosis. RESULTS: Of these 152 patients, 18 had mitral stenosis that was unsuspected clinically until the echocardiogram. These patients were elderly, with a median age of 72 years. They were all referred for echocardiography because of cardiac symptoms. Eight patients were referred for evaluation of congestive heart failure. Five patients were referred for evaluation of aortic valve disease. Three patients were referred because of cerebrovascular accidents and atrial fibrillation. The Doppler-determined mean diastolic mitral gradient ranged from 4 to 15 mm Hg (mean: 7 mm Hg). Mitral stenosis ranged in severity from trivial to very severe. Eight patients had moderate to severe mitral stenosis with estimated mitral valve areas less than or equal to 1.5 cm2. Seven had mild or trivial mitral stenosis with estimated mitral valve areas greater than 1.5 cm2. After further evaluation, two patients underwent mitral valve surgery with improvement of congestive failure. In three patients, warfarin therapy was begun to prevent emboli. Thus, five of 18 patients had a significant immediate change in therapy because of the discovery of mitral stenosis. CONCLUSION: The diagnosis of mitral stenosis may not be suspected in the presence of advanced age, other serious cardiac and medical conditions, or mechanical factors that complicate the physical examination. In these patients, mitral stenosis may be hemodynamically significant and may cause significant symptoms.

Adult↗
PubMed1991

Plaque pH modulations of children's favourite snacks.

Cariogenic potential of a few children's favourite snacks, assessed by evaluation of pH modulations on their respective consumption after 2,5,10,20,30 and 40 minutes compared to 10 percent sucrose control using pooled plaque method, in 8-12 years old children revealed lollipop (hard sucking candy) to be the most cariogenic and samosa without chutney to be the least cariogenic. The cariogenic potential of ice creams were similar, however, low as compared to sucrose solution of 10 percent.

Candy↗
PubMed1990

Cytoplasmic assembly of small nuclear ribonucleoprotein particles from 6 S and 20 S RNA-free intermediates in L929 mouse fibroblasts.

Newly transcribed small nuclear RNAs (snRNAs) appear transiently in the cytoplasm where they assemble with snRNP core proteins (B, D, E, F, and G) stored in large pools of snRNA-free intermediates before returning permanently to the nucleus. In this report, the cytoplasmic assembly of snRNP core particles in L929 mouse fibroblasts was investigated by kinetic analysis of assembly intermediates resolved on sucrose gradients. Immunoprecipitation of gradient fractions with anti-snRNP autoimmune antisera identify pools of 6 and 20 S snRNA-free snRNP protein intermediates. The snRNP B protein has a heterodisperse sedimentation from 4 to 20 S with peaks at 6 and 20 S, and the snRNP D protein is in a bimodal distribution at 6 and 20 S. At 6 S the D protein is assembled with the E, F, and G proteins into a RNA-free core particle with a stoichiometry of D4EFG. SnRNP assembly proceeds by snRNA assembling initially with the 6 S D4EFG particle and then two copies of the B protein to form an 11-15 S SnRNP particle. The 20 S forms of the D protein in the cytoplasm are less stable than the 6 S D4EFG particle. The U1-specific A and C proteins leak from isolated nuclei and appear in the cytoplasmic fractions where they sediment from 10 to 20 S and from 4 to 8 S, respectively.

Animals↗
PubMed1990

Two Systems for Concentrating CO(2) and Bicarbonate during Photosynthesis by Scenedesmus.

Scenedesmus cells grown on high CO(2), when adapted to air levels of CO(2) for 4 to 6 hours in the light, formed two concentrating processes for dissolved inorganic carbon: one for utilizing CO(2) from medium of pH 5 to 8 and one for bicarbonate accumulation from medium of pH 7 to 11. Similar results were obtained with assays by photosynthetic O(2) evolution or by accumulation of dissolved inorganic carbon inside the cells. The CO(2) pump with K(0.5) for O(2) evolution of less than 5 micromolar CO(2) was similar to that previously studied with other green algae such as Chlamydomonas and was accompanied by plasmalemma carbonic anhydrase formation. The HCO(3) (-) concentrating process between pH 8 to 10 lowered the K(0.5) (DIC) from 7300 micromolar HCO(3) (-) in high CO(2) grown Scenedesmus to 10 micromolar in air-adapted cells. The HCO(3) (-) pump was inhibited by vanadate (K(i) of 150 micromolar), as if it involved an ATPase linked HCO(3) (-) transporter. The CO(2) pump was formed on low CO(2) by high-CO(2) grown cells in growth medium within 4 to 6 hours in the light. The alkaline HCO(3) (-) pump was partially activated on low CO(2) within 2 hours in the light or after 8 hours in the dark. Full activation of the HCO(3) (-) pump at pH 9 had requirements similar to the activation of the CO(2) pump. Air-grown or air-adapted cells at pH 7.2 or 9 accumulated in one minute 1 to 2 millimolar inorganic carbon in the light or 0.44 millimolar in the dark from 150 micromolar in the media, whereas CO(2)-grown cells did not accumulate inorganic carbon. A general scheme for concentrating dissolved inorganic carbon by unicellular green algae utilizes a vanadate-sensitive transporter at the chloroplast envelope for the CO(2) pump and in some algae an additional vanadate-sensitive plasmalemma HCO(3) (-) transporter for a HCO(3) (-) pump.

Journal Article↗
PubMed1990

Salicylhydroxamic Acid (SHAM) Inhibition of the Dissolved Inorganic Carbon Concentrating Process in Unicellular Green Algae.

Rates of photosynthetic O(2) evolution, for measuring K(0.5)(CO(2) + HCO(3) (-)) at pH 7, upon addition of 50 micromolar HCO(3) (-) to air-adapted Chlamydomonas, Dunaliella, or Scenedesmus cells, were inhibited up to 90% by the addition of 1.5 to 4.0 millimolar salicylhydroxamic acid (SHAM) to the aqueous medium. The apparent K(1)(SHAM) for Chlamydomonas cells was about 2.5 millimolar, but due to low solubility in water effective concentrations would be lower. Salicylhydroxamic acid did not inhibit oxygen evolution or accumulation of bicarbonate by Scenedesmus cells between pH 8 to 11 or by isolated intact chloroplasts from Dunaliella. Thus, salicylhydroxamic acid appears to inhibit CO(2) uptake, whereas previous results indicate that vanadate inhibits bicarbonate uptake. These conclusions were confirmed by three test procedures with three air-adapted algae at pH 7. Salicylhydroxamic acid inhibited the cellular accumulation of dissolved inorganic carbon, the rate of photosynthetic O(2) evolution dependent on low levels of dissolved inorganic carbon (50 micromolar Na-HCO(3)), and the rate of (14)CO(2) fixation with 100 micromolar [(14)C] HCO(3) (-). Salicylhydroxamic acid inhibition of O(2) evolution and (14)CO(2)-fixation was reversed by higher levels of NaHCO(3). Thus, salicylhydroxamic acid inhibition was apparently not affecting steps of photosynthesis other than CO(2) accumulation. Although salicylhydroxamic acid is an inhibitor of alternative respiration in algae, it is not known whether the two processes are related.

Journal Article↗
PubMed1990

Incidence of australia antigen (HBs Ag) in Himachal Pradesh.

2405 high risk subjects (1193 patients attending STD clinics, 1012 blood donors and 200 hospital personnel) and 500 apparently healthy individuals representing all the twelve districts of the State of Himachal Pradesh were screened for HBs Ag employing reverse passive haemagglutination (RPHA) technique. HBs Ag positivity was found to be 6.77 per cent in test groups and 3.6 per cent in the control group. Maximum positivity was found in STD patients (9.55 per cent) followed by hospital personnel (8 per cent) and blood donors (3.26 per cent). The highest incidence was noticed in district Kullu and no positive case was found in Lahaul and Spiti district of Himachal Pradesh. Remedial measures for prevention of Hepatitis-B virus infection have been emphasized.

Adult↗
PubMed1990

Neonatal outcome following cesarean birth: a prospective study.

Neonatal morbidity and mortality in 573 singleton cesarean born infants was recorded. In 70% of women, it was a primary cesarean section. The neonatal mortality was 3.6% in babies born to primigravida mothers and 9.8% in infants of multigravida. Mortality in male and female infants was 5.73 and 9.65%, respectively. Preterm infants registered more than 7 times higher mortality than term infants. Birth weight below 2000 g and above 3500 g were associated with higher asphyxia rate and neonatal death. Neonatal morbidity frequently encountered was birth asphyxia (19.19%), septicemia (13.43%), jaundice (15.70%) and respiratory problems (23.0%).

Birth Weight↗
PubMed1990

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)

Complement C3↗
PubMed1989

Variations in the Alternative Oxidase in Chlamydomonas Grown in Air or High CO(2).

Chlamydomonas in the resting phase of growth has an equal capacity of about 15 micromole O(2) uptake per hour per milligram of chlorophyll for both the cytochrome c, CN-sensitive respiration, and for the alternative, salicylhydroxamic acid-sensitive respiration. Alternative respiration capacity was measured as salicylhydroxamic acid inhibited O(2) uptake in the presence of CN, and cytochrome c respiration capacity as CN inhibition of O(2) uptake in the presence of salicylhydroxamic acid. Measured total respiration was considerably less than the combined capacities for respiration. During the log phase of growth on high (2-5%) CO(2), the alternative respiration capacity decreased about 90% but returned as the culture entered the lag phase. When the alternative oxidase capacity was low, addition of salicylic acid or cyanide induced its reappearance. When cells were grown on low (air-level) CO(2), which induced a CO(2) concentrating mechanism, the alternative oxidase capacity did not decrease during the growth phase. Attempts to measure in vivo distribution of respiration between the two pathways with either CN or salicylhydroxamic acid alone were inconclusive.

Journal Article↗
PubMed1989

Uptake of inorganic carbon by isolated chloroplasts from air-adapted dunaliella.

Neither Dunaliella cells grown with 5% CO(2) nor their isolated chloroplasts had a CO(2) concentrating mechanism. These cells primarily utilized CO(2) from the medium because the K((0.5)) (HCO(3) (-)) increase from 57 micromolar at pH 7.0 to 1489 micromolar at pH 8.5, where as the K((0.5)) CO(2) was about 12 micromolar over the pH range. After air adaptation for 24 hours in light, a CO(2) concentrating mechanism was present that decreased the K(0.5) (CO(2)) to about 0.5 micromolar and K(0.5) (HCO(3) (-)) to 11 micromolar at pH 8. These K(0.5) values suggest that air-adapted cells preferentially concentrated CO(2) but could also use HCO(3) (-) from the medium. Chloroplasts isolated from air-adapted cells had a K((0.5)) for total inorganic carbon of less than 10 micromolar compared to 130 micromolar for chloroplasts from cells grown on high CO(2). Chloroplasts from air-adapted cells, but not CO(2)-grown cells, concentrate inorganic carbon internally to 1 millimolar in 60 seconds from 240 micromolar in the medium. Maximum uptake rates occurred after preillumination of 45 seconds to 3 minutes. The CO(2) concentrating mechanism by chloroplasts from air-adapted cells was light dependent and inhibited by 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU) or flurocarbonyl-cyamidephenylhydrazone (FCCP). Phenazine-methosulfate at 10 micromolar to provide cyclic phosphorylation partially reversed the inhibition by DCMU but not by FCCP. One to 0.1 millimolar vanadate, an inhibitor of plasma membrane ATPase, inhibited inorganic carbon accumulation by isolated chloroplasts. Vanadate had no effect on CO(2) concentration by whole cells, as it did not readily cross the cell plasmalemma. Addition of external ATP to the isolated chloroplast only slightly stimulated inorganic carbon uptake and did not reverse vanadate inhibition by more than 25%. These results are consistent with a CO(2) concentrating mechanism in Dunaliella cells which consists in part of an inorganic carbon transporter at the chloroplast envelope that is energized by ATP from photosynthetic electron transport.

Journal Article↗
PubMed1989

Two isozymes of dihydroxyacetone phosphate reductase in dunaliella.

Two isoforms of dihydroxyacetone phosphate reductase were present in Dunaliella tertiolecta. The major form was located in the chloroplast and the minor form in the cytosol. The chloroplastic reductase eluted first from a DEAE cellulose column followed immediately by the cytosolic form. Both forms were unstable and cold labile. Addition of 5 millimolar dithiothreitol helped to stabilize the enzymes. The cytosolic isoform of DHAP reductase was detected only if the cells were in an active log phase of growth. Then its activity was 20 to 30% of the total reductase activity. When cell cultures entered late log phase of growth the activity of the cytosolic form of the enzyme disappeared, but the chloroplastic form remained. The cytosolic DHAP reductase from Dunaliella has some properties similar to the cytosolic isoform from spinach leaves. Detergents inhibited both enzymes. However, neither form of the algal dihydroxyacetone phosphate reductase was stimulated by fructose 2,6-bisphosphate. In Dunaliella the properties of the chloroplastic form were those expected for glycerol production for osmoregulation, whereas the cytosolic form, like the reductases in leaves, is more likely involved in glycerol phosphate formation for lipid synthesis.

Journal Article↗
PubMed1988

Isolation of Intact Chloroplasts from Dunaliella tertiolecta.

Cells of Dunaliella tertiolecta from the log phase of growth were broken by rapid extrusion at low pressure through a Yeda press and the chloroplasts were isolated by centrifugation through a Percoll gradient. Osmolarity of the growth media, the suspending media, and the Percoll gradient was kept identical to minimize change in chloroplast volume and mitochondrial entrapment. The isolated intact chloroplasts were obtained in a 30 to 50% yield based on chlorophyll and were stable to washing with buffered medium. Isolated chloroplast yield and purity was dependent on cell culture condition; a cycle of 16 hours light and 8 hours dark with continuous high CO(2) was optimum. Isolated chloroplasts were about 90% intact by microscopic examination, ferricyanide-dependent O(2) evolution, and the distribution of four stromal enzymes. Enzymes associated with glycolate metabolism were not in the chloroplast fraction. The isolated chloroplasts with 10 millimolar bicarbonate evolved 24 micromoles of O(2) and fixed 21 micromoles of CO(2) per hour per milligram of chlorophyll, which rates were about one-third of those by whole cells. The inhibition of oxygen evolution by 10 millimolar phosphate was reversed by P-glycerate. Whole chloroplasts were also isolated from cells adapted to low CO(2) in air for 24 hours. On low CO(2) the cells excreted more gelatinous material, which had to be removed with additional washing of the cells, before it was possible to obtain good chloroplast preparations.

Journal Article↗