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Biomedical subjects

H Singh

Publications and source records attributed to H Singh.

At least 559 records · Page 31Linked to original sources
PubMed1978

Synthesis of substituted 1-hydroxy-2-naphthanilides as potential cestodicidal agents.

A series of substituted 1-hydroxy-2-naphthanilides 4--14 has been synthesized by treating 1-hydroxy-2-naphthoic acids 2 with substituted anilines 3. The nitronaphthanilides, on reduction and subsequent treatment with thiophosgene, gave the corresponding substituted 2-naphthanilide isothiocyanates 30--33. Substitution of the chlorine of 8 by various cyclic amines gave 3'-nitro-4'-substituted 1-hydroxy-2-naphthanilides 15--21. Various 3-aryl-4-oxo-2,3-dihydro-1,3-naphthoxazine-2-thiones 34-43 and 3 aryl-2,4-dioxo-2,3-dihydro-1,3-naphthoxazines 44--51 have been prepared by reacting the corresonding naphthanilides with thiophosgene and ethyl chloroformate, respectively. All the compounds were tested for their cestodicidal activity against Hymenolepis nana infection in rats; 30 was found to be the most active compound of the series, showing 100% clearance of infection at a single oral dose of 7.5 mg/kg.

Anilides↗
PubMed1978

Myxoma of the tricuspid valve.

Myxomas of the intraventricular cavity are extremely rare, and those of right ventricular origin are the least frequent. Only three cases of myxoma of the tricuspid valve have so far been reported. In this communication a myxoma of the tricuspid valve in a 23-year-old woman is reported because of its unusual and interesting clinical presentation and the extreme rarity of this lesion.

Adult↗
PubMed1977

Effect of temperature and protonation upon the conformation of 2'-o-methyladenosine. Correlation of conformational parameters in purine nucleosides.

Proton magnetic resonance studies of 2'-o-methyladenosine in 2H2O have been carried out at variable temperature and p2H. The chemical shifts and H-H coupling constants are discussed in terms of the molecular conformation. Comparison of the data with those of adenosine reveals that 2'-O-methylation has little influence on the conformation. At neutral p2H where the adenine base is not protonated, the molecules favor a 2' endo, gauche-gauche conformation. Protonation of the base at the N(1) position leads to a decrease in the 2' endo, gauche-gauche bias. The data for 2'-O-methyladenosine and adenosine, as well as for several other purine derivatives, reveal the presence of a correlation between the sugar pucker and the C(5')-C(4') conformer distribution which is the inverse of the correlation previously reported for pyrimidine derivatives.

Adenosine↗
PubMed1977

Late evaluation of patients undergoing valve replacement with the Björk-Shiley prosthesis.

This study analyzes 484 patients who survived mitral, aortic, or mitral and aortic valve replacement using the Björk-Shiley prosthesis from January, 1970, through December 31, 1974. Long-term follow-up of 1 1/2 to 6 1/2 years (mean, 3.67 yr) was done on 435 patients (98.2%). Eighty to 85% of the patients have improved noticeably. Thromboembolic problems occurred in 6.9%, representing 1.5 emboli per 1,000 patient-months. Anticoagulant bleeding problems occurred in 6.4% of the patients; late mortality was 15%. Actuarial survival curves showed patients at risk to 6 years having a 79% chance of survival. The same analysis according to preoperative New York Heart Association Functional Classification showed a striking reduction in survival in class IV patients. The Björk-Shiley prosthesis is a good choice for valve replacement today. Earlier diagnosis and treatment are needed to obtain better long-term survival.

Adolescent↗
PubMed1977

Synthesis of 5-chloro-3'-nitro-4'-substituted salicylanilides, a new series of anthelmintic and antimicrobial agents.

A number of 5-chloro-3'-nitro-4'-substituted salicylanilides (6--23) have been synthesized by treating 4',5-dichloro-3'-nitrosalicylanilide (5) with various sodium aryl oxides, alkoxides, or amines. These compounds have been tested against Hymenolepis nana infection in rats and have also been evaluated for their in vitro antimicrobial activity against various strains of bacteria and fungi. In the former test 17 was the most active cestodicidal agent showing activity at 30 mg/kg. In the antimicrobial screening, 22 inhibited the growth of all the bacteria and fungi used while 6 was active against the penicillin resistant Staphylococcus aureus at a minimum inhibitory concentration of 0.00609 microgram/mL.

Animals↗
PubMed1977

Topical or no anaesthesia for external urethral sphincterotomy in neurogenic vesical dysfunction due to spinal injury.

Considerable controversy exists regarding the ideal anaesthetic coverage for external urethral sphincterotomy in spinal injury patients with detrusor-sphincter dyssynergia. From this preliminary experience on 34 patients in whom this procedure was indicated and then attempted under topical (urethral instillation of 20 ml of 2 per cent Lignocaine jelly) or no anaesthesia, we are encouraged into believing that these patients may not require general or regional anaesthesia for this operation.

Aged↗