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Biomedical subjects

P K Basu

Publications and source records attributed to P K Basu.

At least 91 records · Page 5Linked to original sources
PubMed1982

Effects of acidic lake water on the eye.

The normal eyes of 6 men and 21 rabbits were exposed to samples of lake water, one eye to a sample of pH 4.6 and the other to a sample of pH 6.3. The men's eyes were exposed for 5 minutes on four occasions a week apart, whereas the rabbits' eyes were exposed for 15 minutes either on one occasion or once a day for 7 days. In the humans neither sample of water produced symptoms or signs of an adverse effect on the external eye tissues, apart from brief conjunctival congestion after every exposure. In the rabbits the two samples did not appear, in general, to have different effects on the ocular tissues, as judged from the osmolarity and cell count of the tears, conjunctival congestion, corneal staining with fluorescein, corneal permeability and histologic features of the cornea. In a few instances differences were observed, but their pathological significance was not apparent. These data suggest that lake water of a pH as low as 4.6 may not harm healthy eyes, however, larger and broader studies are essential.

Acids↗
PubMed1981

Effect of hydrocortisone on the mobilisation of leucocytes in corneal wounds.

We have studied in rabbits the effect of subconjunctivally injected hydrocortisone on the polymorphonuclear leucocyte invasion of corneal wounds at different times after an injury. One group of rabbits was treated with the steroid (hydrocortisone group) and the other not (control group). After making nonpenetrating trephine incisions on the cornea we obtained cellular samples by the impression technique at a given postoperative period (2, 4, or 6 hours), and then the animal was killed. The cornea was processed for histological study of the infiltrating cells. At any postoperative period the number of polymorphonuclear leucocytes in the corneal wounds of the hydrocortisone group was significantly less than the number in the identical wounds of the control group (p less than 0.01 to 0.001).

Animals↗
PubMed1981

Impression cytology in conjunctivitis.

A technique is described for studying the cellular response in various conjunctival disorders. A round plastic disc (Thermanox) is pressed against the patient's conjunctive, and the material adhering to the disc is stained with a modified Wright's stain (Diff-Quik) for light microscopy. This method compares favourably with the classic conjunctival scraping method. The advantages of the impression technique are that no local anesthetic is needed for abtaining conjunctival samples, it is painless and can readily be used in children, repeated samples can be taken within a short time, the staining procedure can be completed within 15 seconds, and the discs can be processed for electron microscopic studies of the cellular samples.

Adolescent↗
PubMed1981

Enhancement and inhibition of phagocytic activity in the retinal pigment epithelium.

The phagocytic activity of the pigmented epithelium of the bovine retina was studied with an organ culture model. Latex particles coated with immunoglobulin, or bovine rod outer segments, both labelled with radioactive iodine, were the objects to be phagocytosed. Various agents were tested with this model for their effects on phagocytosis by the retinal pigment epithelium. Iodoacetate significantly inhibited phagocytosis, as did penicillin, though to a lesser extent. Concanavalin A and gentamicin enhanced phagocytosis. Dimethyl sulfoxide had no effect. The results with lymphokines were not conclusive.

Animals↗
PubMed1980

Contaminated renal allografts.

Bacterial contamination of a renal allograft may cause infection of the transplant with eventual loss of the graft and possibly death of the patient. We report two cases that illustrate these complications and that support the suggestion that culture of the transport medium is a valuable investigation prior to transplantation.

Bacteroides Infections↗
PubMed1980

Proportions of T- and B-lymphocytes in preauricular lymph nodes and aqueous humour of rabbits showing corneal graft reactions.

We wished to determine the proportions of T- and B-lymphocytes in the preauricular lymph nodes and the anterior chambers of rabbits during various stages of graft reactions. The animals received unilateral orthotopic corneal xenografts or skin allografts on the ear. The target cells were identified with the use of fluorescein-tagged antisera specific for rabbit T- and B-lymphocytes. As compared with the percentage in the rabbits that had not received a graft, in both the xenograft and the allograft recipients the percentage of T-lymphocytes in the preauricular lymph nodes during the graft reaction did not change on the side that received the graft but was higher on the side that did not receive a graft. In the recipients of the corneal grafts, as the severity of the graft reaction increased, the percentage of B-lymphocytes in the preauricular lymph nodes on the side that received the graft and the percentage of T-lymphocytes in the lymphoid cell population infiltrating the anterior chamber of the grafted eye increased. The possible mechanisms underlying these phenomena are discussed.

Animals↗
PubMed1980

Effect of cigarette smoke on the surface structure of the conjunctival epithelium.

Syrian golden hamsters were exposed to cigarette smoke in an intermittent smoke exposure device, and the surface structure of the tarsal conjunctiva was compared with that of sham-smoked and cage-held controls. Scanning electron microscopy revealed distortion and loss of microvilli of the conjunctival cells in the smoke-exposed animals.

Animals↗
PubMed1980

Quantitative correlation between the reduction of nitroblue tetrazolium and the oxygen uptake of corneal cells.

We wished to measure the amount of reduced nitroblue tetrazolium (NBT) formed in corneal cells and to relate it to the viability of the cells in terms of their oxygen uptake. Two full-thickness corneal discs of identical size (3, 4, 5 or 6 mm in diameter) were cut from the eyes of guinea pigs. One disc was processed for the measurement of its reduced NBT and cellular nitrogen content; the other was processed for the measurement of its oxygen uptake and deoxyribonucleic acid (DNA) content. As the diameter of the corneal disc (that is, the number of cells) increased, the quantity of reduced NBT, nitrogen and DNA and the oxygen uptake increased proportionality. Since each of these measures correlated positively with each other (P less than 0.01) we were able to estimate the number of viable cells in a given cornea by measuring the amount of reduced NBT (formazan granules) formed in the cells.

Animals↗
PubMed1980

Damage to corneal endothelial cells by lysosomal enzymes in stored human eyes.

We wished to see if the concentration of lysosomal enzymes in the aqueous humour had any relation to the number of dead corneal endothelial cells in stored eyes from human donors. Forty pairs of eyes were obtained: one eye of each pair was tested immediately and the other was tested after storage in a moist chamber at 4 degrees C for up to 10 days. The aqueous humour of each eye was aspirated and the concentration of acid phosphatase (a marker of lysosomal hydrolytic enzymes) was measured. Simultaneously the numbers of dead and living cells per unit area of the corneal endothelium were counted following their staining with trypan blue and p-nitroblue tetrazolium respectively. As the storage time increased, the concentration of acid phosphatase in the aqueous humour increased and the number of living corneal endothelial cells decreased. The number of living cells decreased to about 50% at an average enzyme concentration of 9 X 10(-3) muM/h. The eyes stored for less than 3 days were the least damaged.

Acid Phosphatase↗
PubMed1979

Glucose oxidation in fresh guinea pig cornea.

The rate of glucose oxidation of fresh corneas of guinea pigs at different ages has been determined. Full-thickness corneal discs, 4 mm in diameter, were incubated in radioactive glucose solution. The quantity of the released CO2 was expressed in terms of the corneal discs, their dry weights, and DNA and protein contents. The rate of glucose metabolized to CO2 per hour was about 300 pmol/microgram DNA for guinea pigs weighing approximately 800 g. Glucose oxidation decreased as the age of the animals increased. Our results compared well with those obtained in other species. We therefore feel that the guinea pig should be a suitable model for research on the metabolism of corneas.

Animals↗