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Biomedical subjects

C Ramesh

Publications and source records attributed to C Ramesh.

At least 19 recordsLinked to original sources
PubMed2006

Evaluation of genetic potential of the polyvoltine silkworm (Bombyx mori L.) germplasm and identification of parents for breeding programme.

In the present study, polyvoltine germplasm stock of Andhra Pradesh State Sericulture Research and Development, Institute (APSSRDI) was evaluated for its performance based on quantitative and qualitative traits. Twenty-one oval and 10 peanut cocoon shaped lines were reared in different seasons of the year. Since the polyvoltines are non-diapausing, six generations were reared and evaluated for various economically important traits based on evaluation index and sub-ordinate function statistical methods. Ten top ranked lines obtained by using both the methods were identified as potential parental strains. Among oval lines, APM14, APM11, APM18, APMW9, and APM19, and among peanut lines APMD5, APMD1, APMD3, APMD9 and APMD8 were selected as base material. The identified high yielding lines will be used in various breeding programmes as initial parents for the synthesis of superior polyvoltine breeds/hybrids.

Animals↗
PubMed2004

Application of the micronucleus test to exfoliated epithelial cells from the oral cavity of beedi smokers, a high-risk group for oral cancer.

The primary sites for occurrence of oral cancer include the buccal mucosa, tongue, alveolus, palate, lip and the floor of the mouth. In this study, an attempt was made to estimate the cytogenetic damage in different regions of the oral mucosa in people habituated to smoking beedi,which is one of the major forms of tobacco consumption in India and believed to be a major risk factor for oral cancer. By using the micronucleus assay on exfoliated cells from the buccal mucosa, palate and tongue of beedi smokers, we examined an early cellular response to the effect of beedi smoking. A total number of 50 randomly selected male subjects were included in the study. Case and control groups (smokers and non-smokers, respectively) comprised 25 subjects each. The difference in mean micronucleated cell count between cases and controls was significant (P <0.01) for buccal mucosa and palate, but not for tongue. The correlation between age and micronucleus cell count was weak for both cases (r=0.27) and controls (r=0.36).

Adult↗
PubMed2003

Simple, efficient, and selective deprotection of phenolic methoxymethyl ethers using silica-supported sodium hydrogen sulfate as a heterogeneous catalyst.

A simple and efficient method has been developed for chemoselective deprotection of phenolic methoxymethyl (MOM) ethers using silica-supported sodium hydrogen sulfate as a heterogeneous catalyst. The conversions occur at room temperature, and the yields of the deprotected phenols are excellent. The method is suitable for deprotection of phenolic MOM ethers of multifunctional bioactive natural products.

Journal Article↗
PubMed2003

Charminarone, a seco-pseudoguaianolide from Parthenium hysterophorus.

A novel sesquiterpenoid, charminarone, the first seco-pseudoguaianolide, has been isolated along with several known compounds from the whole plant of Parthenium hysterophorus. The structure of the new compound has been settled as 1,10-seco-dihydroisoparthenin 1,10-dione from its spectral data as well as from its conversion by reductive coupling reaction with Zn/TiCl(4) reagent to the known compound, anhydrodihydroisoparthenin. The reagent Zn/TiCl(4) has been used here for the first time to construct the seven membered ring of a pseudoguaianolide sesquiterpenoid.

Asteraceae↗
PubMed2003

Pseudoguaianolides from the flowers of Parthenium hysterophorus.

Chemical investigation on the flowers of Parthenium hysterophorus has resulted in the isolation of four new pseudoguaianolides, hysterones A-D along with the known compounds, parthenin, coronopilin, 2beta-hydroxycoronopilin and tetraneurin-A. The structures of the new compounds were established by interpretation of their spectral (1D and 2D NMR) data. The X-ray crystallographic analysis of hysterones A and C was also carried out.

Asteraceae↗
PubMed2000

Increased QT variability in patients with panic disorder and depression.

This study investigated beat-to-beat QT variability in patients with panic disorder and depression, and normal control subjects using an automated algorithm to compute QT intervals. An increase in QT variability appears to be associated with symptomatic patients with dilated cardiomyopathy and also with an increased risk for sudden death. QT(vm) (QT variability normalized for mean QT interval) and QT(vi) (a log ratio of QT variance normalized for mean QT over heart rate variability normalized for mean heart rate) were significantly higher in patients with panic disorder and depression in supine as well as standing postures (P=0.002 and 0.0001 for QT(vm) and QT(vi), respectively). In another analysis, QT(vi) was significantly higher in patients with panic disorder compared to control subjects in supine as well as standing postures during spontaneous breathing as well as 12, 15 and 20 per minute breathing (P=0.005). These findings are important especially in view of the recent reports of increased risk for cardiovascular mortality and sudden death in patients with anxiety and depression and the utility of QT(vi) as a noninvasive measure of temporal repolarization lability.

Adult↗
PubMed2000

Effects of nortriptyline and paroxetine on QT variability in patients with panic disorder.

This study investigated beat-to-beat QT variability in patients with panic disorder before and after treatment with nortriptyline (n = 13) and paroxetine (n = 16), using an automated algorithm to compute QT intervals. An increase in QT variability appears to be associated with symptomatic patients with dilated cardiomyopathy and also with an increased risk for sudden cardiac death. QTvi (QT variability index: a log ratio of QT variance normalized for mean QT over heart rate variability normalized for mean heart rate) was significantly higher in supine posture in patients with panic disorder treated with nortriptyline (P = 0.006) but not paroxetine. Thus paroxetine may be a better drug of choice especially in patients with coexisting cardiac disease. These findings are important especially in view of the recent reports of increased risk for cardiovascular mortality and sudden death in patients with anxiety and depression. QTvi can be a valuable noninvasive measure of temporal repolarization lability, especially to study the side effects of medications which affect cardiac autonomic function.

Adult↗
PubMed2000

X-ray microanalysis of elements of VA mycorrhizal and non-mycorrhizal Pennisetum pedicellatum roots.

Chemical composition of inter and intracellular hyphae was elucidated in Pennisetum pedicellatum roots colonized by Gigaspora margarita by employing energy dispersive X-ray microanalysis. Maximum amount of phosphate was estimated in polyphosphate granules present in the roots. Amount of phosphate was low in fungal hyphae, arbuscular trunks and degenerated arbuscules. Elements S, K and Ca were present in the hyphae, arbuscular trunk and degenerated arbuscules.

Electron Probe Microanalysis↗
PubMed2000

Comparison of protein profiles and enzymes in non-mycorrhizal and mycorrhizal roots of Pennisetum pedicellatum.

Pennisetum pedicellatum plants were inoculated with Glomus mosseae, G. aggregatum and Gigaspora margarita. There were both quantitative and qualitative changes in the protein pattern of inoculated plants. Gi. margarita induced increase in protein in the plants. Acid phosphatase, alkaline phosphatase, superoxide dismutase and chitinase activities were high at the beginning of infection, but declined as the infection advanced. Gi. margarita was an efficient fungus in enhancing enzyme activity and proteins in roots compared with G. mosseae and G. aggregatum. Protein profile revealed the presence of 12 peaks in mycorrhizal plants compared with 8 in nonmycorrhizal plants.

Fungi↗
PubMed1998

Role of electron beam treatment in postoperative management of carcinoma of the breast.

The aim of post operative radiotherapy to chest wall and drainage areas in advanced breast cancer is to sterilize the possible microscopic disease. Fifty cases of post surgical breast cancers were evaluated in a prospective study of chest wall radiation therapy by electrons. Fifty women of histologically proved post operative invasive breast cancers underwent simple mastectomy with axillary dissection followed by post-operative radiotherapy (Electron) to chest wall +/- drainage area. The chest wall and IMC was treated by a direct electron beam (9/12 MeV and 12 MeV) at fixed angle. 6 MV X-ray beam was used to treat axillary apex and supraclavicular area. In some cases, supplement RT was given by 6 MV X-rays through small posterior axillary portal. The energy of electron beam was 9 MeV or 12 MeV depending on the thickness of treated area. The supraclavicular and axillary lymphatic regions were treated, by direct custom shaped anterior portal. The dose delivered was 50 Gy over 5 weeks at 2 Gy per fraction. Adjuvant chemotherapy was given to patients who were pre-menopausal with histologically proved axillary node involvement as Cyclophosphamide, Methotrexate and 5-Fluorouracil (CMF) after radiotherapy. Post menopausal patients received adjuvant tamoxifen 10 mg.bid. The overall time varied from 26 to 87 days with a median of 41.5 days (SD 11.7). The followup period varied from 4-32 months with a mean of 22 months (SD 6.4). All the fifty patients developed dense pigmentation towards the end of radiation therapy, along with patchy dry desquamation. Moist desquamation occurred in 6 patients. The median OTT in the patients who developed moist desquamation was 34.5 days. The moist reaction healed over 10-15 days after completion of radiotherapy. Lung Fibrosis (Apical lobe) occurred in four patients. The fibrosis was evident at a median of 12 months of follow up. Lymphoedema of the ipsilateral arm occurred in six patients. None of 50 patients developed late sequalae like Cardiac effects, Rib fracture, Brachial Plexopathy, Shoulder joint impairement and Soft tissue effects. Local control in this study was 96% (48 patients). The two year actuarial overall survival was 80%. In early stages survival was significantly better compared to late stages. The actuarial two year DFS was 72%. In early stages DFS was significantly better compared to late stages.

Adult↗
PubMed1996

Calcium channel blockers for anxiety disorders?

The role of calcium in the etiology of anxiety has been proposed for several decades. Calcium channel blockers profoundly influence calcium metabolism and the transport of calcium. Even though the evidence for the role of calcium remains weak, drugs affecting calcium might be useful in the treatment of anxiety disorders. One of these compounds, verapamil, has been used to treat mood disorders. Calcium channel blockers have also been tried in other indications such as premenstrual syndrome, irritable bowel syndrome, schizophrenia, tardive dyskinesia, and Tourette's syndrome. However, the number of articles on the use of calcium channel blockers in the treatment of anxiety disorders is low. Three reports (two open, one double-blind) described some success in the treatment of panic disorder with verapamil, diltiazem, or nimodipine and one open-label study described unsuccessful treatment of anxiety and phobia with nifedipine in patients with various anxiety disorders. Further double-blind placebo-controlled studies of calcium channel blockers in the treatment of anxiety disorders are warranted to determine a possible role of these compounds in the armamentarium of antianxiety drugs.

Anxiety Disorders↗
PubMed1996

Primary central nervous system lymphoma a report of nine cases.

Primary Central Nervous System Lymphoma (PCNSL) is a rare neoplasm of B cell origin and constitute less than 1% of Non-Hodgkin's lymphoma (NHL). Histology is mainly of high grade and intermediate type. Although NHL is known to be highly sensitive to both irradiation and cytotoxic drugs, being a curable malignancy, the therapeutic results remain disappointing. Clinical observations on nine cases of PCNSL seen in one of the major cancer centres in India is presented in this paper. Radiotherapy combined with Chemotherapy although yielded encouraging initial response in these patients, the long term response was unsatisfactory with median survival for these patients being only 19 months. This warrants an alternative therapeutic approach to improve the dismal prognosis of PCNSL.

Adult↗
PubMed1995

Effects of isoproterenol infusions on heart rate variability in patients with panic disorder.

Some evidence suggests that patients with panic disorder have a decreased cardiac vagal and a relatively higher sympathetic activity. In this study, spectral analysis of the time series of heart rate before and after isoproterenol infusions was used to study heart rate variability in six panic disorder patients and 11 normal control subjects. These preliminary data reveal a significant increase of sympathovagal ratios only in the patient group after isoproterenol administration. The findings suggest a relative increase in cardiac sympathetic and a relative decrease in cardiac vagal function in patients with panic disorder during isoproterenol infusions.

Adrenergic beta-Agonists↗
PubMed1995

Blood pressure, heart rate, and skin temperature in preterm infants: associations with periventricular haemorrhage.

The mean arterial blood pressure (MABP), heart rate, and skin temperature were monitored every 15 minutes in the first 10 days after birth in 34 preterm infants, gestational age 24 to 33 weeks. Ultrasound brain scans carried out daily showed that a periventricular haemorrhage (PVH) occurred in a subgroup of infants (n = 15) of lower birthweight and gestational age. In infants without PVH the daily median of MABP increased with birthweight and postnatal age; that of heart rate was not affected by postnatal age, body weight, or gestational age; and that of skin temperature showed a slight fall with postnatal age. In infants with PVH, on or before the day of PVH, daily medians of MABP and skin temperature were not significantly different from those of infants without PVH, but the daily median of heart rate tended to be slightly higher. The percentage of positive correlations between the 96 15 minute values per day for heart rate and MABP increased with postnatal age and with birthweight, but did not differ in infants who developed a PVH. The coefficient of variation (CV) of the 96 15 minute values for MABP tended to be higher in infants on the day of PVH, and a similar trend was apparent on the day before. The processes of development of blood pressure, heart rate, and skin temperature are similar in infants with or without PVH but at lower gestational ages altered blood pressure control may cause brain haemorrhage.

Birth Weight↗
PubMed1995

Spinal cord compression by primary non-Hodgkin's lymphoma.

Epidural Cord Compression (ECC) by primary lymphomas is rare entity and constitutes less than 3% of total malignant lymphoma with Non-Hodgkin's Lymphoma (NHL), diffuse large cell type being the most common histological subtype. In this paper 16 cases of primary NHL with cord compression seen at the Department of Medical Oncology, during the period 1988-1990 are reviewed. At presentation all patients had undergone Laminectomy with decompression of epidural mass. The histological diagnosis of NHL was subclassified according to the International working formulation and was evaluated for disease process elsewhere in the body. All patients with ECC by lymphoma received high dose steroids with concurrent Radiotherapy (local) and combination Chemotherapy. These patients had longer duration of neurological deficit prior to treatment had poor response. After 6 courses of chemotherapy 50% of the patients had complete neurological recovery (CR), 31% had partial neurological recovery (PR) and in 19% there was no neurological recovery (NR).

Adolescent↗
PubMed1994

Effects of nortriptyline on heart rate variability in panic disorder patients: a preliminary study using power spectral analysis of heart rate.

Previous reports on heart rate variability suggest that, compared to controls, panic disorder patients have a higher relative mid-frequency (MF) (0.07-0.15 Hz) power in standing posture and that they also have a greater increase in standing MF power after the administration of yohimbine. We studied the effects of nortriptyline, a tricyclic antidepressant, on HR variability measures in 13 panic disorder patients before and after successful treatment. There was a highly significant increase in supine and standing HR (p = 0.00001) while there was a significant decrease of standing absolute and relative MF power (p = 0.009 and 0.0001 respectively). This uncontrolled preliminary study suggests a decrease in sympathetic activity related to nortriptyline treatment in addition to its anticholinergic effects.

Adult↗