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Biomedical subjects

B K Patnaik

Publications and source records attributed to B K Patnaik.

At least 55 records · Page 3Linked to original sources
PubMed1979

Long-term vitamin status and dietary intake of healthy elderly subjects. 1. Riboflavin.

1. Long-term clinical and biochemical riboflavin status and dietary intake of riboflavin were monitored for 18 months in a group of twenty-three relatively-healthy elderly subjects living at home in the north of England. 2. Both dietary intake and biochemical status, as measured by the activation coefficient (stimulated:basal activity) of NAD(P)H2:glutathione oxidoreductase (EC 1.6.4.2), remained fairly constant for each individual and for most subjects the usual intake and biochemical status were characterized quite accurately by a single week's intake dietary record and a single measurement of the activation coefficient. 3. The expected relationship between biochemical status and dietary intake was present, but not strongly evident. There was a significant within-subject correlation between alpha values and the immediately preceding dietary intake; however the between-subject correlation between alpha values and dietary intake approached zero if the two subjects receiving long-term riboflavin supplements were omitted. Over the limited range of intakes observed in unsupplemented subjects, non-dietary factors evidently obscure the relationship. 4. Although eight subjects had average values above 1.2 for the activation coefficient, no excessively high values were observed, and no subject showed any clear-cut clinical deficiency symptoms.

Aged↗
PubMed1979

Effect of short-term cold stress on the respiratory metabolism of brain tissue homogenates of male garden lizards of two different age-groups.

The endogenous oxygen uptake and the uptake with added substrate of whole-brain and mid-brain homogenates were significantly lower in older lizards as compared to younger. Both whole brain and mid-brain showed responses to cold stress for different lengths of time but the decline in oxygen uptake was more pronounced in the younger age-group. Respiratory rate and response to cold stress were more marked in the mid-brain than in the whole brain. Basing on earlier reports on mammals and on the present findings, it is suggested that the decline in physiological adaptation in older animals may be a general feature in vertebrates.

Adaptation, Physiological↗
PubMed1979

In vivo and in vitro effects of alloxan on collagen characteristics of bone, skin and tendon of Swiss mice.

Alloxan diabetes in Swiss mice induced decreased levels of percent solubility of collagen in bone, skin and tendon both after 4 days (96 h) and 28 days of treatment. In vitro treatment of tissues with alloxan in physiological saline did not influence the cross-linking of collagen. It is suggested that in alloxan diabetes, metabolites formed in the tissues might accelerate aging of collagen.

Alloxan↗
PubMed1978

Age changes in collagen characteristics of bone and skin of a short-lived species of reptile.

Decalcified bone collagen of older male garden lizards, Calotes versicolor, was less susceptible to digestion by collagenase from Clostridium histolyticum than that from younger individuals. In aged skin the percentage solubility and the soluble/insoluble collagen ratio decreased, with a concomitant rise in insoluble and total collagen. Collagen/unit area increased with advancing age in both dorsal and ventral skin. These results from a non-mammalian poikilothermic vertebrate provide additional evidence in favour of the cross-linkage theory of ageing and suggest a common pattern of collagen ageing in vertebrates.

Aging↗
PubMed1978

Age-related changes in collagenous and noncollagenous proteins of skeletal muscle of a short-lived species of reptile.

The collagenous/noncollagenous protein ratio in the skeletal muscle of the male garden lizard increased with advancing age, suggesting increased tensile strength of aged muscle. The solubility of collagen and the soluble/insoluble collagen ratio showed a decline during ageing confirming the development of cross-linkages in the muscle collagen of ageing lizards. It is suggested that these changes are likely to disturb the efficiency of ageing muscle.

Aging↗
PubMed1978

A short term study on the growth of garden lizards in the laboratory.

Male garden lizards weighing between 2 to 17.5 g and having a snout to vent length range of 4.5 to 8.7 cm were collected from nature during the breeding season and reared in the laboratory at 28 +/- 2 degrees C for a period of 6 months. There was a high mortality rate but those which survived showed excellent positive correlation between bodyweight and time (r = 0.97, P is less than 0.001) and between S-V length and time (r=0.98, P is less than 0.001). The length and body weight relationship during the period of study was also highly significant (r=0.99, P is less than 0.001).

Animals↗