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Biomedical subjects

R B Singh

Publications and source records attributed to R B Singh.

At least 37 records · Page 2Linked to original sources
PubMed2004

Intravenous lidocaine suppresses fentanyl-induced coughing: a double-blind, prospective, randomized placebo-controlled study.

IV lidocaine is effective in suppressing the cough reflex of tracheal intubation, extubation, bronchography, bronchoscopy, and laryngoscopy. We investigated this effect of lidocaine on fentanyl-induced cough in 502 patients of ASA physical status I and II scheduled for elective surgery. The patients were assigned to 2 equal groups to receive either lidocaine 1.5 mg/kg or placebo (0.9% saline) over 5 s 1 min before the administration of fentanyl 3 mug/kg in a randomized and double-blind fashion. Coughs were classified as coughing and graded as mild (1-2), moderate (3-4), or severe (5 or more). The results of the study suggest that IV lidocaine 1.5 mg/kg, when administered 1 min before fentanyl, is significantly effective in suppressing fentanyl-induced cough compared to placebo (0.9% saline) (218 versus 165 patients) (P < 0.002) but without affecting the severity of cough (P > 0.05).

Adult↗
PubMed2004

How brain influences neuro-cardiovascular dysfunction.

Mechanisms that may explain the association between brain-heart connection leading to abnormal heart rate variability (HRV) and blood pressure variability (BVP) resulting into increased morbidity and mortality due to cardiovascular diseases (CVD), are reviewed. Medline search till December, 2001 and articles published in various national and international journals were reviewed. Experts working in the field were also consulted. There is compelling evidence that saturated and total fat and sedentary behaviour can enhance sympathetic activity and increase the secretion of catecholamine, cortisol and serotonin, whereas omega-3 fatty acid supplementation may enhance parasympathetic activity and increase the secretion of acetylcholine in the hippocampus. While increased sympathetic activity has adverse effects on HRV and BPV, increased parasympathetic activity has beneficial effects and can directly inhibit sympathetic tone. A large body of evidence is available demonstrating that abnormal HRV measured over a 24-hour period, or for 7 days, provides information on the risk of subsequent death in subjects with and without heart disease. Meditation, beta blockers, ACE inhibitors, n-3 fatty acids, trimetazidine and oestrogen may have a beneficial influence on HRV. However, no definite and specific therapy is currently available to improve the prognosis for patients with abnormal HRV and blood pressure variability (BPV). Low HRV has been most commonly associated with a risk of arrhythmias and arrhythmic death, unstable angina, myocardial infarction, progression of heart failure and atherosclerosis. There is a need to develop a consensus on the measure of HRV for clinical purposes and whether 7-day record is necessary and practical. New analysis methods based on nonlinear dynamics may be more useful in risk stratification. More precise insight into the patho-physiological link between HRV and nutrition may be applied to clinical practice and used to direct therapy for prevention of disease risk.

Autonomic Nervous System↗
PubMed2004

Investigation on the phenolics of some spices having pharmacotherapeuthic properties.

Spices are an important group of agricultural commodities being used by many civilizations all over the world to aid flavor, taste and nutritional values in the food. In traditional medical systems, their ability to heal various physical, mental and emotional problems has widely been reported. With this view, HPLC analysis was performed to estimate phenolic acids in 21 spices (asafetida, Bishop's weed, black mustard, coriander, cinnamon, clove, curry leaf, cumin black, cumin, fennel, fenugreek, garlic, ginger, Indian cassia, Indian dill or dill large cardamom, onion, saffron, tamarind, true cardamom, yellow mustard) commonly used in India in different forms. In all, 7 phenolic acids; viz., tannic, gallic, caffeic, cinnamic, chlorogenic, ferulic and vanillic acids could be identified on the basis of their retention time with standard compounds and co-chromatography. Several parts of the spices, for instance, seeds, leaves, barks, rhizomes, latex, stigmas, floral buds and modified stems were used in the study. Maximum amount of tannic and gallic acids was observed in black mustard and clove. Caffeic, chlorogenic and ferulic acids were found maximum in cumin while vanillic and cinnamic acids in onion seeds. The spices are known to significantly contribute to the flavor, taste, and medicinal properties of food because of phenolics.

Antioxidants↗
PubMed2003

Partially de-epithelialized preputial flap (triangular soft tissue flap): an aid to prevent coronal urethrocutaneous fistulae.

A technique is described to fashion a partially de-epithelialized preputial flap, also called triangular soft tissue flap (TSTF), to cover the neourethra in the region of glans, corona and subcorona. This highly vascular TSTF acted as a mechanical barrier against coronal fistula formation in 16 subcoronal hypospadiacs aged 3-12 years who underwent Snodgrass tubularized incised plate urethroplasty. None had complications at 1-year of follow-up.

Child↗
PubMed2002

Glove-finger dressing in paediatric hypospadias.

Dressing post-operative hypospadias using a glove finger is technically easy to apply, inspect, and remove; gives uniform compression; is cheap and easily available; prevents contamination; and does not slip like ordinary dressings.

Bandages↗
PubMed2002

Brain-heart connection and the risk of heart attack.

Autonomic functions, such as increased sympathetic and parasympathetic activity and the brain's suprachiasmatic nucleus, higher nervous centres, depression, hostility and aggression appear to be important determinants of heart rate variability (HRV), which is, itself, an important risk factor of myocardial infarction, arrhythmias, sudden death, heart failure and atherosclerosis. The circadian rhythm of these complications with an increased occurrence in the second quarter of the day may be due to autonomic dysfunction as well as to the presence of excitatory brain and heart tissues. While increased sympathetic activity is associated with increased levels of cortisol, catecholamines, serotonin, renin, aldosterone, angiotensin and free radicals; increased parasympathetic activity may be associated with greater levels of acetylecholine, dopamine, nitric oxide, endorphins, coenzyme Q10, antioxidants and other protective factors. Recent studies indicate that hyperglycemia, diabetes, hyperlipidemia, ambient pollution, insulin resistance and mental stress can increase the risk of low HRV. These risk factors, which are known to favour cardiovascular disease, seem to act by decreasing HRV. There is evidence that regular fasting may modulate HRV and other risk factors of heart attack. While exercise is known to decrease HRV, exercise training may not have any adverse effect on HRV. In a recent study among 202 patients with acute myocardial infarction (AMI), the incidence of onset of chest pain was highest in the second quarter of the day (41.0%), mainly between 4.0-8.0 AM, followed by the fourth quarter, usually after large meals (28.2%). Emotion was the second most common trigger (43.5%). Cold weather was a predisposing factor in 29.2% and hot temperature (> 40 degrees celsius) was common in 24.7% of the patients. Dietary n-3 fatty acids and coenzyme Q10 have been found to prevent the increased circadian occurrence of cardiac events in our randomized controlled trials, possibly by increasing HRV. We have also found that n-3 fatty acids plus CoQ can decrease TNF-alpha and IL-6 in AMI which are pro-inflammatory agents. There is evidence that dietary n-3 fatty acids canenhance hippocampal acetylecholine levels, which may be protective. Similarly, the stimulation of the vagus nerve may inhibit TNF synthesis in the liver and acetylecholine, the principal vagal neurotransmitter, significantly attenuates the release of pro-inflammatory cytokines TNF-alpha, interleukin 1,6 and 18, but not the anti-inflammatory cytokine IL-10 in experiments. Therefore, any agent which can enhance brain acetylecholine levels, may be used as a therapeutic agent in protecting the suprachiasmatic nucleus, higher nervous centres, vagal activity and sympathetic nerve activity which are known to regulate the body clock and HRV and the risk of SCD and heart attack.

Brain↗
PubMed2002

Circadian variation of basal total vascular tone and chronotherapy in patients with vasospastic angina pectoris.

Vasospastic angina pectoris (VSA) is an anginal attack which occurs characteristically between night and early morning. The aim of this study was to clarify the cause of VSA. The subjects consisted of 16 patients with VSA, 18 patients with effort angina (EAP) and 15 healthy individuals, who were used as the control group. Subjects were attached to an ambulatory blood pressure monitor and a non-invasive continuous cardiac output monitor concurrently, over a 24-hour period. Mean blood pressure (MBP), and cardiac index (CI) were measured. Then basal total vascular tone (TVT) was calculated as follows: basal TVT = (MBP/CI) x 1,332 dyne/sec/cm5. The decrement of CO was greater during sleeping hours as compared with the decrement of the MBP in the VSA group. Nocturnal basal TVT was significantly greater in the VSA group than in the EAP group or the control group. The increased nocturnal basal TVT was significantly suppressed by long acting calcium antagonists to the level of the EAP and the control groups. The treatment also decreased the frequency of ischemic attacks.

Adult↗
PubMed2002

Purse-string closure of a mucous fistula in loop colostomy.

The technique of purse-string closure of a mucous fistula to prevent faecal contamination during loop colostomy is described in six patients who underwent the procedure. Complete faecal diversion was achieved in all six patients without complications.

Colonic Diseases↗
PubMed2002

New insights into circadian aspects of health and disease.

Early awakening and early to bed as well as good conduct, thought, diet, interpersonal dealings and physical activity have been suggested for healthy life in Ayurveda. Circadian rhythms, coordinated in part by the parietal hypothalamic-pituitary and adrenal mechanisms, have been reported in almost all variables examined thus far, including the circulation. It is possible that all metabolic functions undergo circadian rhythms. It remains to be explored whether these rhythms may be optimized by Ayurvedic practices. The onsets of myocardial ischemia, unstable angina, acute myocardial infarction, sudden cardiac death, and strokes have been reported to exhibit a circadian variation, with increased frequency in the second quarter of the day. An increased physical and mental load caused by an attempt to prepare for the day may be important in triggering acute cardiovascular events. Depending on their timing, meditation (Ayurvedic practice), n-3 fatty acids, coenzyme Q10, beta-blockers and estrogens may have beneficial effects, whereas progestins and mental load may have adverse effects on heart rate and blood pressure variability, which may be expressed by different circadian patterns. Around the clock serial recordings of blood pressure and heart rate during usual activities and lifestyles may be recorded and may be analyzed by computer-implemented curve fitting to assess the about 24-hour (circadian) variation, among other rhythmic, chaotic, and trend components of the time structure (chronome) of these variables. The new disease risk syndrome circadian hyper-amplitude-tension (CHAT), a condition characterized by an excessive circadian amplitude of blood pressure, cannot be ascertained on the basis of single casual blood pressure measurements. The International Chronome Ecological Study of Heart Rate (and blood pressure) Variability in various ethnic groups aims at collecting further evidence regarding the role of blood pressure and heart rate variability in the pathogenesis of cardiovascular events, while also examining any role played by ethnicity and lifestyle-associated factors.

Blood Pressure↗
PubMed2001

Can nutrition influence circadian rhythm and heart rate variability?

Recent studies indicate that there is an interaction between biorhythms, the biological clock and triggers, which may be important in the pathogenesis of altered heart rate variability (HRV) and blood pressure variability (BPV). Circadian rhythms are under the influence of, and physiological variables are mediated by the activation of the adrenals, sympathetic/parasympathetic, hypothalamic and pituitary activity. Emotional stress, physical exertion, sleep deprivation and large fatty meals are major triggers of myocardial ischemia, angina, infarction, sudden cardiac death (SCD) and stroke. These events have been reported to exhibit a circadian variation with increased frequency in the second quarter of the day, which has also been observed in our studies on Indians. Recent studies indicate that altered HRV and BPV are also important in the pathogenesis and progression of heart failure, atheroma and thrombosis. Mediation via beta-blockers, oestrogens, n-3 fatty acids, vitamin E and coenzyme Q10 and fasting appears to have a beneficial influence whereas progestins, nifedipine, stress and exercise may have an adverse effect on HRV and BPV. We have reported that plasma levels of vitamin E and C are lower in the second quarter of the day than at other times, indicating their role in the pathogenesis of variability and cardiac events. Prospective studies also indicate that HRV and BPV are important and independent risk factors for cardiovascular events. However, no study has yet been conducted in patients with abnormal HRV and BPV in a randomized, placebo-controlled intervention trial to find out whether improvement in variability can cause a significant reduction in cardiovascular events. There is a need to study the role of n-3 fatty acids, coenzyme Q10, the effect of regular physical training, medication and ACE inhibitors in patients with abnormal HRV and BPV to demonstrate that improving variability can modulate cardiovascular events.

Animals↗