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Biomedical subjects

S Hegde

Publications and source records attributed to S Hegde.

At least 37 records · Page 2Linked to original sources
PubMed1999

Structured sedation programme for magnetic resonance imaging examination in children.

One thousand, eight hundred and fifty-seven patients underwent magnetic resonance imaging following the establishment of a structured sedation programme. Forty-eight of these patients came from the intensive care unit with a secure airway and were therefore excluded from any further analysis. Oral sedation was to be given to children aged 5 years and below. For children >/= 6 years old, oral sedation could be given only if their level of co-operation was judged to be inadequate by the referring physician. Oral sedation consisted of chloral hydrate 90 mg x kg-1 (maximum 2.0 g) orally with or without rectal paraldehyde 0.3 ml x kg-1. All magnetic resonance imaging requests for children who failed oral sedation as well as those referred for general anaesthesia from the outset were reviewed by a consultant anaesthetist who then allocated patients to undergo the procedure with either general anaesthesia or intravenous sedation. Scans requiring intravenous sedation or general anaesthesia were performed in the presence of a consultant anaesthetist. Intravenous sedation consisted of either a propofol 0.5 mg x kg-1 bolus followed by an infusion (maximum 3 mg x kg-1 x h-1) or midazolam 0.2-0.5 mg x kg-1 boluses. General anaesthesia was given using spontaneous ventilation with a mixture of 66% nitrous oxide in oxygen and isoflurane following either inhalation (sevoflurane) or intravenous (propofol) induction. One thousand and thirty-nine (57.4%) of the scans were done without sedation whereas 93 scans were performed during the consultant anaesthetist supervised sessions. Oral sedation failed in 50 out of 727 patients (6.9%). Eighty-seven per cent of children aged 5 years and below needed sedation compared with 4.5% of those aged over 10 years. Two patients who had only received chloral hydrate developed significant respiratory depression. This structured sedation programme has provided a safe, effective and efficient use of limited resources.

Adolescent↗
PubMed1999

Mandibular talon cusp: report of two rare cases.

Two rare cases of talon cusps in the mandibular incisors were observed during a prevalence study on talon cusp. One of them was seen on a mandibular primary lateral incisor. The other one was observed on the mandibular left permanent central incisor, and the right mandibular permanent central incisor was congenitally missing. There were no associated developmental syndromes with either of the cases reported. Of the 4770 children examined, nine cases had talon cusp with only two rare cases of mandibular talon cusp, one in the primary dentition and the other in the permanent dentition.

Adolescent↗
PubMed1999

Heterozygous germline ATM mutations do not contribute to radiation-associated malignancies after Hodgkin's disease.

PURPOSE: The successful treatment of Hodgkin's disease has been associated with an increased incidence of secondary malignancies. To investigate whether genetic factors contribute to the development of secondary tumors, we collected family cancer histories and performed mutational analysis of the ataxia-telangiectasia (AT) gene, ATM, in a cohort of Hodgkin's disease survivors with secondary malignancies. ATM was chosen for evaluation because of the increased radiosensitivity of cells derived from AT patients and obligate heterozygotes and the epidemiologic observation that AT carriers are at increased risk for radiation-induced breast cancer. PATIENTS AND METHODS: Fifty-two patients who developed one or more neoplasms after treatment for Hodgkin's disease participated in this study. Personal and family histories of cancer were obtained through patient interviews and review of medical records. ATM mutational analysis was performed using a yeast-based protein truncation assay. RESULTS: Seventy-six secondary neoplasms were observed in this cohort of 52 Hodgkin's disease survivors, with 18 patients (35%) developing more than one secondary neoplasm. Positive family histories of cancer were present in 11 (21%) of 52 patients, compared with three (4%) of 68 Hodgkin's disease patients in a comparison cohort who did not develop secondary neoplasms (P =.008; Fisher's exact test). No germline ATM mutations were identified, resulting in an estimated AT carrier frequency in this population of 0% (90% confidence interval, 0% to 4%). CONCLUSION: Analysis of the number of tumors per individual and the family history of cancer in our cohort suggests that genetic factors may contribute to development of secondary neoplasms in a subset of Hodgkin's disease survivors. Mutational analysis, however, does not support a significant role for heterozygous truncating ATM mutations. Future studies evaluating other genes involved in DNA damage response pathways are warranted.

Adolescent↗
PubMed1999

Inhibition of intraocular tumor growth by topical application of the angiostatic steroid anecortave acetate.

PURPOSE: This study examined the effect of an angiostatic agent on the growth of a highly vascularized intraocular tumor. METHODS: A murine uveal melanoma cell line (99E1) was transplanted intracamerally into athymic nude BALB/c mice. Mice were treated topically three times per day beginning on the day of tumor transplantation and continuing through day 28. Groups included (a) 1% anecortave acetate, (b) vehicle control, or (c) no treatment. Tumor growth was scored clinically according to the volume of anterior chamber occupied by tumor. Intraocular tumor weights were determined on days 10, 14, 21, and 28. The effect of the test agents on tumor cell proliferation was examined in vitro by [3H]thymidine incorporation. RESULTS: Tumors grew progressively in untreated mice and mice treated with the vehicle; tumors filled the entire eye by day 20 and frequently perforated the globe by day 21. By contrast, tumors treated with anecortave acetate grew significantly slower (P < 0.025) and did not perforate the eye. On days 21 and 28 the net tumor weight of the AL-3789-treated animals was 40% to 30% of controls (P < 0.05). Tumor inhibition was presumably due to the angiostatic properties of anecortave acetate because the compound did not affect tumor cell proliferation in vitro. CONCLUSIONS: The topical ocular administration of anecortave acetate restricted the growth of a highly vascularized angiogenic intraocular tumor.

Administration, Topical↗
PubMed1998

Gender effect on beta-endorphin response to exercise.

PURPOSE: Twelve healthy men (26.4 yr) and women (26.8 yr) were compared at rest and after cycling for 25 min at 60 and 80% VO2max to determine whether gender and menstrual cycle influenced circulating beta-endorphin concentration (BE). METHODS: VO2max was determined on a cycle ergometer, and subjects completed the exercise in a randomized order. Women were tested in both the luteal (L) and follicular (F) phases of their menstrual cycle, which was confirmed by their blood estrogen levels. All tests were conducted in the morning after a 30-min rest (12-h postabsorptive). An indwelling venous catheter placed in a forearm vein enabled blood sampling at rest, 25 min of cycling, and 25 min of recovery. RESULTS: Resting BE was similar for men before both 60 and 80% intensities of exercise, 5.27 +/- 0.43 and 5.30 +/- 0.33 pmol.mL-1, respectively. BE was not significantly changed at 60% VO2max (6.54 +/- 0.33 pmol.mL-1) but significantly increased at 80% VO2max (11.90 +/- 1.98 pmol.mL-1). Women tended to have slightly lower BE during the L compared with F, but this did not reach significance (L = 4.40 +/- 0.22, F = 4.73 +/- 0.30 pmol.mL-1). Cycling at 60% VO2max did not significantly increase BE in the L (5.41 +/- 0.42 pmol.mL-1) nor the F (5.35 +/- 0.40 pmol.mL-1). Cycling at 80% VO2max increased BE to a similar extent in both the L and F phase, respectively (10.44 and 10.96). Although the BE concentrations tended to be slightly lower in women compared with men at 80% VO2max, this did not reach statistical significance. CONCLUSIONS: These data suggest that women cycling at 80% VO2max will have a similar BE response to men independent of their menstrual cycle. BE in women at rest and who exercise at lower exercise intensities may have slightly lower BE levels then men independent of the time of the women's menstrual cycle.

Adolescent↗
PubMed1998

Influence of the maternal vaginal microbiota on the oral microbiota of the newborn.

The present study was conducted on 50 expectant mothers and the newborns, with the aim of observing if any, the relationship, acquisition and survival of the maternal vaginal microbiota to the oral microflora after birth. The oral cavity was sterile in 6% of the newborns. The differences between the counts of S. aureus, Klebsiella, Lactobacillus, Ps. aeruginosa and Veillonella sp. in the mother and in the child were of statistical significance. No statistically significant difference was observed between the counts of S. epidermidis in the mother and in the child. Of the microorganisms present at birth, only S. epidermidis persisted in the oral cavity. At the end of the observation period, S. salivarius was the predominant oral microorganism.

Bacteria↗
PubMed1998

Pharmacokinetic profile of a new 3-azinomethyl rifamycin (SPA-S-565) in volunteers as compared with conventional rifampicin.

The pharmacokinetics and tolerance of a single oral dose (150 mg) of a new 3-azinomethyl rifamycin (SPA-S-565, USAN rifametane) was compared with 150 mg of conventional rifampicin in six healthy volunteers. The mean maximum concentration (Cmax) of SPA-S-565 was 3.94 +/- 0.26 micrograms/ml, and resulted significantly higher as compared with the Cmax after rifampicin, which was 2.89 +/- 0.20 micrograms/ml. The mean maximum time (tmax) for SPA-S-565 was 2.1 +/- 0.3 h as compared with that of rifampicin, which was 1.6 +/- 0.3 h, the difference between these values not being statistically significant. The elimination half-life (t1/2) of SPA-S-565 was 17.5 +/- 2.6 h in contrast to the half-life of 2.8 +/- 0.26 h seen with rifampicin; the difference was found to be highly significant. The mean area under the serum concentration curve from 0 to the last detectable concentration (AUC0-t) and the mean area under the serum concentration-versus-time curve from 0 to infinity (AUC0-infinity) of SPA-S-565 were almost six times than those obtained with conventional rifampicin. The differences between the two compounds were highly significant. In all cases except one volunteer all the biochemical parameters remained within normal range following single oral dose administration of SPA-S-565. In one volunteer, although there was a slight rise in serum alkaline phosphatase above the normal range, the original value itself was at the very upper limit of the normal range (i.e., 80 IU/L). Although there was a significant increase in the levels of serum alkaline phosphatase, serum gamma-glutamyl transpeptidase (GGTP) and serum amylase levels, 24 h following the administration of SPA-S-565 these levels remained within the normal range.

Administration, Oral↗
PubMed1997

Down syndrome with biparental inheritance of der(14q21q) and maternally derived trisomy 21: confirmation by fluorescent in situ hybridization and microsatellite polymorphism analysis.

Individuals with translocation Down syndrome (DS) often inherit the rearranged chromosome from a carrier parent. DS due to inheritance of one Robertsonian or derivative (14q21q) from one parent and a second der(14q21q) in addition to a free chromosome 21 from the other parent are rarely documented in liveborn infants. Presented here is such a propositus with DS and with a unique karyotype 45,XY,der(14;21) (p11.1;p11.1)pat,der(14;21)(p11.1;q11.1)mat, +21mat. Using conventional chromosome heteromorphisms, fluorescent in situ hybridization (FISH), and microsatellite polymorphism analyses, we established the biparental origin of the 2 der(14q21q) and the maternal origin of the extra chromosome 21 in the patient. A combination of both cytogenetic and molecular genetic techniques also enabled us to show that the 2 der(14q21q) were not identical by descent and hence the parents were nonconsanguineous. It has been a well-established fact that mothers with Robertsonian translocations have higher risk for nondisjunction than do carrier fathers. Our case, wherein the nondisjunctional event occurred in the mother, even though both parents are carriers of a 14;21 Robertsonian translocation, is yet another example of this.

Chromosome Banding↗
PubMed1997

Prevalence of malocclusion and periodontal status in Tibetan school children of Kushalnagar, Mysore district.

A representative sample of 817 Tibetan school children aged 7 to 17 years of Mysore district were examined for malocclusion, gingival bleeding and calculus, using plane mouth mirror, sickle explorer and periodontal probes, under natural light. A very slight increase in malocclusion was noted in school girls, in addition to the statistically significant increase in gingival bleeding among 8-13 years and 17 year old girls and 7-10 years and 15-16 year old boys. Moreover, a highly statistically significant increase in calculus was perceived amongst girls. The present study thus showed an increasing demand for preventive and therapeutic dental treatment in these children and early identification of such individuals at risk, can lead to better disease management.

Adolescent↗
PubMed1997

Down syndrome associated malformations.

This paper reports the associated malformations and the clinical findings that were observed in 417 cytogenetically confirmed Down Syndrome patients. Among them congenital heart defects have occurred more frequently [75; 17.98%] than osteoarticular malformations [23; 5.52]; eye anomalies [22; 5.27%]; and gastroenterological malformations [n 16; 3.84%]. With regard to prognosis and treatment appropriate counselling has been given to Down Syndrome patients and their families.

Adolescent↗
PubMed1995

Induction of cell-mediated immune responses to human immunodeficiency virus type 1 Gag protein by using Listeria monocytogenes as a live vaccine vector.

Cytolytic T cells, acting through cytokines or by direct lysis of infected target cells, have been shown to play a significant role in the control of viral infections and may be responsible for the prolonged asymptomatic phase following infection by HIV. Accordingly, methods that can generate strong cell-mediated immune responses may be useful in the development of prophylactic and therapeutic vaccines against HIV. Listeria monocytogenes is a Gram-positive intracellular microorganism that elicits strong cell-mediated immune responses against its own secreted proteins following infection. In this study we have modified the chromosome of L. monocytogenes so that it stably expresses and secretes the p55 HIV gag gene product and examined the cell-mediated immune response of BALB/c mice to infection with this recombinant organism. Infected animals were found to mount a specific, strong, long-lasting CD8+ cytolytic T cell response against a predominant epitope contained within the p24 fragment of the HIV Gag protein. This epitope previously has been shown to be recognized by CTLs obtained from some HIV-infected humans. Our results suggest that chromosomally modified strains of L. monocytogenes may provide valuable vaccine vectors for use against HIV.

AIDS Vaccines↗
PubMed1995

recO and recR mutations delay induction of the SOS response in Escherichia coli.

RecF, RecO and RecR, three of the important proteins of the RecF pathway of recombination, are also needed for repair of DNA damage due to UV irradiation. recF mutants are not proficient in cleaving LexA repressor in vivo following DNA damage: therefore they show a delay of induction of the SOS response. In this communication, by measuring the in vivo levels of LexA repressor using anti-LexA antibodies, we show that recO and recR mutant strains are also not proficient in LexA cleavage reactions. In addition, we show that recO and recR mutations delay induction of beta-galactosidase activity expressed from a lexA-regulated promoter following exposure of cells to UV, thus further supporting the idea that recF, recO and recR gene products are needed for induction of the SOS response.

Bacterial Proteins↗
PubMed1995

Mechanical ventilation of newborns: experience from a level II NICU.

OBJECTIVES: To analyse the indications, clinical profile, complications and outcome of the babies requiring mechanical ventilation. DESIGN: Retrospective study. SETTING: NICU of a teaching hospital. SUBJECTS: One hundred and twenty one neonates requiring assisted ventilation during three years. RESULTS: Of 121 babies 59(48.76%) survived. Hyaline membrane disease (HMD) was the commonest indication for ventilation followed by birth asphyxia, apnea of prematurity, meconium aspiration syndrome (MAS) and septicemia. Infants with HMD whose birth weight was more than 1.5 kg and those who required ventilation after 24 hours of birth had better outcome. Survival rates increased with increasing birth weight and gestational age. Prolonged ventilatory support was needed for HMD (mean 117.3 hr) and MAS (mean 82.6 hr). Pneumonia was the commonest complication, followed by sepsis, air leak syndromes and intracranial and pulmonary hemorrhage. CONCLUSIONS: Ventilatory facilities must be focussed for neonates weighing > 1000 g. Assisted ventilation may not be cost-effective in patients weighing < or = 1000 g and those with complex heart diseases and other congenital anomalies.

Cost-Benefit Analysis↗
PubMed1992

Cytogenetic investigations in Down syndrome patients & their parents.

A total of 1343 mentally retarded patients referred for cytogenetic evaluation were studied. Of these Down syndrome was confirmed in 365 (21.17%). There were 316 patients of trisomy 21 (86.58%); 21 of mosaicism (5.75%) and 28 of translocation (7.67%). Trisomy 21 patients with chromosomal variants were observed in 17 (4.65%). A 1.37:1 male:female ratio was seen. Karyotyping was also done on 182 parents (of patients of mosaic Down, translocation Down and trisomy 21 with chromosomal variants and in parents with suspected low mosaicism). Mosaic trisomy 21 cell line was found in one mother (0.27%); 6 parents (1.65%) were seen to be translocation carriers and 7 had chromosomal variants (1.92%). Cytogenetic investigations help to give appropriate genetic counselling to patients and their families.

Adolescent↗