Search PubMed⌕ Search

Biomedical subjects

S D Singh

Publications and source records attributed to S D Singh.

At least 37 records · Page 2Linked to original sources
PubMed1989

Pharmacokinetic data on doxycycline and its distribution in different biological fluids in female goats.

A pharmacokinetic study of doxycycline after intravenous administration at 5 mg/kg body weight in goats revealed that a concentration of greater than or equal to 0.5 microgram/ml was maintained for 5 min-2 h, 4-12 h, 2-12 h and 5 min-greater than 48 h in plasma, interstitial fluid, milk and urine respectively. The low t1/2 alpha of 0.73 +/- 0.11 h and high t1/2 beta of 16.63 +/- 1.58 h show that the drug is rapidly distributed but slowly eliminated from the body. The tissue:plasma concentration of 4.86 +/- 1.06 during the elimination phase [K12/(K21-beta)] indicates a high expected tissue concentration, which is supported by similarly increased drug concentration in interstitial fluid and milk. The high Vdarea of 9.78 +/- 0.86 L/kg observed denotes that, apart from its wide distribution, the drug may be stored in fat depots as it is known to be highly lipophilic. As the drug maintained a therapeutic concentration for a shorter time in plasma, and the calculated dose rate for maintaining a minimal plasma concentration of 0.5-1.5 micrograms/ml is relatively high, it may not be of much use in treating septicaemia in this species. Since the observed tissue:plasma concentration was higher and a therapeutic concentration was maintained in interstitial fluid and milk for longer, the drug can be used for other systemic infections at a lower dose rate than that required for treating septicaemia. As the drug maintained a very high concentration in urine, it may be of particular value in treating urinary tract infections caused by sensitive micro-organisms.

Animals↗
PubMed1989

Pre-cancerous lesions of stomach.

Total 39 cases of carcinoma stomach were noticed out of 142 malignant tumours of GIT (27.46 percent). Histologically maximum cases were of diffuse type (56.41 percent) followed by intestinal type (35.89 percent) and indolent mucoid carcinoma (7.69 percent) of the stomach. The surrounding epithelium showed lot of changes in the intestinal type of carcinoma stomach. About 78.57 percent showed intestinal metaplasia, 14.28 percent of these cases showed chronic gastric ulcer and severe dysplasia (carcinoma in situ) and another 14.28 percent revealed villous adenoma with carcinoma in situ. In contrast to this, in diffuse variety, only 13.63 percent cases revealed intestinal metaplasia, 27.27 percent showed basal cell hyperplasia, stratification of the epithelium of crypts and diffuse infiltration of mucosa by malignant cells and 4.54 percent showed atrophic gastritis also. In mucoid carcinoma all cases had basal cell hyperplasia and stratification of crypts. Hence these conditions should be taken as premalignant lesions of stomach and should be cured in proper time.

Adenocarcinoma, Mucinous↗
PubMed1989

Clinicopathological studies of carcinoma oesophagus with special reference to changes in surrounding epithelium.

A total 17 cases of carcinoma oesophagus were studied in a period of 2 years. Ten patients (58.82%) were males and rest were females. Maximum cases (64.70%) were seen in 5th and 6th decades. Majority of the patients belonged to low socio-economic group (47.05%) followed by middle socio-economic group (41.17%). Dysphagia was present in all cases, followed by weight loss 52.94% and other symptoms. Cancer was equally distributed in middle third and lower third of the oesophagus (41.18% in each group) only in 3 cases it was in upper third of the oesophagus. Histologically 70.5% tumours were squamous cell carcinoma, 17.64% were adenocarcinoma and 11.76% were undifferentiated carcinoma. Surrounding epithelium in 17.64 per cent cases showed chronic oesophagitis, 4 cases (23.52%) showed acanthosis and dysplasia, and two cases revealed carcinoma in situ. Hence findings of oesophagitis, acanthosis, dysplasia, carcinoma in situ suggest that oesophagitis and acanthosis may be considered as precancerous lesions.

Adenocarcinoma↗
PubMed1987

Pharmacokinetics of streptomycin with particular reference to its distribution in plasma, milk and uterine fluid of she-buffaloes.

The study elucidated the pharmacokinetics of streptomycin in healthy lactating she-buffaloes after a single intramuscular (IM) injection (10 mg/kg). The drug attained its peak concentrations of 24.39 +/- 2.67, 0.45 +/- 0.05 and 5.06 +/- 0.18 micrograms/ml at 1, 4 and 1 hour in plasma, milk and uterine fluid respectively. Calculations based on the assumption of a 2-compartment model gave a plasma t1/2 (beta) of 4.01 +/- 0.44 h and an apparent volume of distribution [Vd(area)] of 0.47 +/- 0.06 1/kg. The drug was detectable in the plasma, milk and uterine fluid for 30, 8 and 12 hours, respectively. A therapeutic concentration of the drug was maintained for 6 to 7 hours in the plasma and for around 1 hour only in the uterine fluid. However, a therapeutic level could not be achieved in milk at any time. The results suggest that the drug can be used clinically by the IM route against streptomycin susceptible systemic infections but not those in the uterus and mammary gland.

Animals↗
PubMed1986

Gestational diabetes and its effect on the umbilical cord.

The structural changes in the umbilical cord of full term fetuses from 18 cases of gestational diabetes were studied. All these were insulin-dependent and their blood glucose levels were well controlled. Light microscopy showed rupture and erosion of the endothelial lining of umbilical arteries resulting in increased permeability and haemorrhages. The umbilical vein was unduly dilated. The smooth muscle in the walls of these vessels showed disruption and degeneration of its fibres. 'Wharton's jelly' showed alteration in the pattern of distribution of its fibres with large empty spaces amongst them. It is suggested that gestational diabetes has a deleterious effect on umbilical vessels and the connective tissue component of 'Wharton's jelly'.

Diabetes Mellitus, Type 1↗
PubMed1986

Internal jugular phlebectasia.

Varicose veins are a common venous anomaly, but rarer varieties also occur including phlebectasia, which is an abnormal dilatation of an isolated vein. Phlebectasia may affect any vein and is usually asymptomatic. When the internal jugular vein is involved, it presents as a cervical swelling that closely mimics the signs of either a pharyngocoele or a laryngocoele and, due to its rarity, is frequently misdiagnosed. A review of the English literature demonstrates that the diagnosis has generally been confirmed either by invasive contrast radiographic techniques, or surgical exploration, though many authors had made a tentative clinical diagnosis prior to surgical confirmation. No treatment is indicated for this benign self-limiting condition, except for the few patients who complain of symptoms and require surgical removal of the affected vein, and therefore, if a diagnosis cannot be made with certainty from the clinical features, investigations should be as non-invasive as possible, employing either a CAT scan or Digital Subtraction Angiography, though the latter is not yet universally available.

Child↗
PubMed1985

The presentation and management of the nasal glioma.

Nasal gliomata are rare and experience in management is therefore not widespread. Clinical details of 5 children with nasal gliomata are presented. In each case the glioma was excised by an external approach without the need for craniotomy. These cases demonstrate the variability of presenting features and problems in management. They illustrate a relatively conservative surgical approach to treatment which we consider to be safe and effective. The characteristics of these unusual neural malformations are reviewed, and the management is discussed.

Female↗
PubMed1985

Nasal glioma.

Explore the source record for details and available documents.

Dermoid Cyst↗
PubMed1984

The fixed cervical lymph node.

A series of almost 2000 patients with squamous carcinoma of the head and neck is presented. Seven percent of the patients had massive fixed glands at the time of presentation. The incidence of fixed nodes varied between sites, and increased with increasing T-stage of the primary tumor. Forty percent of the patients were treated; the most common cause for withholding treatment was advanced age. Radiotherapy did not produce a significant prolongation of survival, but surgery did. Resection of the mandible, the skin of the neck, and the external carotid artery proved to be valuable procedures both in terms of palliation and survival; radical surgery produced a 5-year survival of approximately 15%.

Carcinoma, Squamous Cell↗
PubMed1983

Mortality after surgery for hypopharyngeal cancer.

Results of 362 patients with squamous carcinoma of the hypopharynx are presented. The hospital mortality was 25 per cent for patients treated surgically. The mortality was increased by previous radiotherapy and poor general condition, and also depended on the method of pharyngeal repair: the mortality for visceral (stomach or colon) transposition was higher than that for repair by skin flaps. The chance of long term survival decreased with increasing N stage, and was also reduced for patients undergoing visceral repair compared with skin flap repair of the pharynx.

Aged↗
PubMed1983

Squamous carcinoma of the head and neck: the untreated patient.

One thousand, nine hundred and seventy-seven patients with squamous carcinoma of the head and neck are reviewed with particular reference to the patients not treated. The commonest reason for not treating the patients was that the tumour was too extensive (55%). A further 36% were too old or infirm to be considered fit for radical treatment, and 9% of patients refused treatment. Treated and untreated patients were compared for age, sex, site of the primary and TNM stage. The proportion of patients untreated varied according to site of the primary tumour, with 25% of pharangeal tumours being the highest proportional representation. Median survival for untreated patients was 88 days; survival time was significantly related to sex, T stage of primary tumour and patient's general condition.

Age Factors↗