Contraception in male monkeys by intra-vas deferens injection of a pH lowering polymer

A new male method of contraception by injecting a polymer, styrene-maleic anhydride (SMA), into the lumen of the vas deferens has been studied on rhesus monkeys. The polymer has the dual feature that it can occlude the vas deferens lumen and also it can inhibit the fertilising ability of spermatozoa by virtue of the pH lowering effect. Matings with females were carried out when the lumen was completely occluded giving azoospermia as well as with partial block and spermatozoa present in the semen. All matings were infertile. Data up to one year is presented. All indications are that the contraceptive effect will last for a considerably long period.

Idiopathic hemochromotosis and alpha-1-antitrypsin deficiency: coexistence in a family with progressive liver disease in the proband

A patient with coexistent hemochromatosis and alpha-1-antitrypsin deficiency which led to cirrhosis and death despite adequate therapy for hemochromatosis is reported. Evaluation of the family revealed first degree relatives with iron overload and others with alpha-1-antitrypsin deficiency but none with both conditions. The role of family studies in the early recognition and possible prevention of overt clinical disease in individuals with either of these two genetic diseases is discussed.

Some aspects of biomedical engineering research in New Delhi

Biomedical engineering has been recognized in India for the last decade. Technological developments have been in areas of importance to the country, with several groups actively involved in the promotion of bioengineering, particularly in New Delhi. A group at the National Physical Laboratory has contributed significantly to the field of ultrasonics as well as to the development of piezoelectric transducers for other biomedical uses. The Centre for Biomedical Engineering of the Indian Institute of Technology and the All India Institute of Medical Sciences is one of the country's leading centres producing outstanding work in areas like instrumentation, rehabilitation, biomaterials, modelling and analysis. Research in technology applied to reproductive physiology (an area especially relevant to India's needs) was initiated at this centre. Research at the School of Environmental Sciences, Jawaharlal Nehru University has elucidated the effects and mechanisms of the action of low-energy electromagnetic radiation and ultrasound on biological systems--in one of the school's projects the use of bone material for ultrasonic transducers and optical detectors was successfully demonstrated. A selected list of publications shows the wide spectrum of research carried out at these institutions.

Prenatal and neonatal exposure to cimetidine results in gonadal and sexual dysfunction in adult males

Exposure of rats to cimetidine during intrauterine life and the immediate neonatal period results in hypoandrogenization in adult life with decreased weights of androgen-dependent tissues and decreased concentrations of testosterone. Moreover, sexual behavior patterns in adult life are disturbed as shown by a lack of sexual motivation and decreased performance.

Comparison of electrical field plethysmography with electrical impedance plethysmography

As a means for assessing cardiac function, electrical field plethysmography (EFP) has been shown to have some features quite different from electrical impedance plethysmography (EIP). Here the two techniques are compared by using the two systems simultaneously on a subject and also with independent use in different electrode configurations. The results conform with the view that EIP is related primarily to volumetric changes of the aorta, whereas EFP is affected predominantly by changes in cardiac dimensions and orientation. Because of this difference, the standard time differential formula used for EIP is not applicable for the computation of cardiac output from the EFP waveforms. An alternative method of computation based on the amplitude of the EFP waveform is suggested.

Dynamics of the ampullary-isthmic junction in rabbit oviduct

A delay in the ovum transport at the ampullary-isthmic junction (AIJ) has been confirmed by various investigators, but the mechanism of retention and release at this junction is not yet well understood. Using a technique for monitoring unobstructed Fallopian tube motility with an impedance plethysmograph, an increase in luminal diameter was observed at the time when the ova are released from the AIJ. This enlargement persists till all ova emerge from the AIJ. Hence, it seems likely that the AU relaxation is a dominant factor contributing to ova release from the AIJ.

Resistance of Salmonella serotypes to chloramphenicol

A total of 704 Salmonella strains isolated from various sources were tested for their resistance to chloramphenicol. The results indicate that 36 out of 46 serotypes, comprising 671 strains (95.4%), were sensitive to chloramphenicol up to a level of 10 mug per ml of medium. Most of the strains were sensitive at concentrations between 2 mug and 4 mug of chloramphenicol per ml of medium. None of the strains isolated from animals, including poultry, was resistant. The results indicate that in India resistance of Salmonella strains to chloramphenicol has not increased over the years though this may have occurred in other parts of the world.