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B D Gupta

Publications and source records attributed to B D Gupta.

At least 73 records · Page 4Linked to original sources
PubMed1986

Light-induced interaction between rhodopsin and GTP-binding protein leads to the hydrolysis of GTP in the rod outer segment.

In the presence of exogenous GTP, vertebrate whole rod outer segments (ROS), with perforated plasma membranes in the "single particle" scattering range, elicit a light-induced light-scattering transient which we call the "G" signal. Here, we report on the characteristics of the "G" signal relative to the "binding" and "dissociation" signals reported by Kuhn and colleagues. Replacing GTP with guanylyl imidodiphosphate (GMP-PNP) does not give rise to the G signal. This indicates that hydrolysis of the terminal phosphate is required for the G signal and, in addition, GTP and GMP-PNP compete for the same binding site of the enzyme responsible for the G signal (i.e., GTP-binding protein). Also, neither GDP nor its nonhydrolyzable analogue, guanosine 5'-O-(2-thiodiphosphate), when present in ROS suspensions yield any light-scattering transient in the time period tested.

Animals↗
PubMed1986

Child labor.

Explore the source record for details and available documents.

Adolescent↗
PubMed1985

Testicular germ cell tumors. A review of 10 years' experience.

Experience with 200 cases of testicular tumors seen over a period of 10 years has been presented. Modes of presentation, response to treatment, and patterns of failure have been analyzed in 186 cases of germ cell tumors. The role of radiation in the overall management of seminomas is reaffirmed, and the need for adjuvant radiation to the supraclavicular region and mediastinum is demonstrated in Stage II cases of seminoma. Results of treatment with radiation alone or combined with chemotherapy were not encouraging in nonseminomas in the current series. The advantages of an aggressive multimodal approach with judicious combination of surgery, radiation treatment, and combination chemotherapy have been discussed, with review of relevant literature.

Adolescent↗
PubMed1984

Spatial information capacity of eyes: roles of Na+ channels and photon noise in photoreceptor.

The spatial information capacity of the human eye for photopic vision has been determined taking into account the intensity response function of the photoreceptor. It has been found that spatial information capacity increases with the mean luminance upto a certain value of mean luminance and after that it starts decreasing. The decrement occurs below the damage threshold. These results are in agreement with the reported experimental observations. It has been concluded that the limited number of Na+ channels in the photoreceptor outer segment and the photon noise are responsible for the fall in the information capacity below the damage threshold.

Humans↗