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Biomedical subjects

R Basu

Publications and source records attributed to R Basu.

67 records · Page 4Linked to original sources
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↗
PubMed1979

Indomethacin and uterine evacuation of conceptus in rats: possible mode of action.

Indomethacin at a dose of 2.5 mg/kg from day 18 through day 20 of pregnancy was found to extend the duration of gestation for 2-3 days over the control value. Conversely, prostaglandin F2 alpha (PGF2 alpha) at a dose of 2.0 mg/kg on day 18 of pregnancy induced premature parturition. PGF2 alpha given concurrently with indomethacin resulted in neutralisation of the drug action and the animals delivered viable pups as identically recorded in controls. Failure of indomethacin to extend the length of pseudopregnancy in either bilaterally hysterectomized or bilaterally decidualized pseudopregnant rats revealed that the lengthening of the duration of pregnancy caused by indomethacin is not due to an extension of luteal span, but results from relaxation of the uterine smooth musculature.

Animals↗
PubMed1978

The possible mode of action of prostaglandins: XIV. Evidence of an involvement of progesterone in the initiation of prostaglandin F2a-induced premature labor in rats.

Prostaglandin F2a (PGF2a) at a dose of 2 mg/kg (sc) on day 18 of pregnancy induced premature emptying of gravid uteri by day 21 in the rat. Bilateral spaying or luteectomy on day 18 of pregnancy induced a refractoriness to respond to the abortifacient action of PGF2a. Injection of progesterone in the spayed or luteectomized pregnant rats, however, restored the sensitivity of the surgically manipulated animals to PGF2a. Premature parturition resulted in all of the animals so far tested. The importance of progesterone in terms of the abortifacient action of PGF2a is discussed.

Animals↗
PubMed1978

Pregnant mare's serum gonadotropin. IV. Induction of premature labor by pregnant mare's serum gonadotropin and its prevention by using clomiphene or indomethacin.

The administration of pregnant mare's serum gonadotropin (PMSG), 30 IU on day 18 of pregnancy, resulted in premature labor in rats. However, this abortifacient efficacy of PMSG was not demonstrable when a simultaneous injection of progesterone, clomiphene, or indomethacin was scheduled, thus suggesting that the action of PMSG is medicated by the estrogen-stimulated release of prostaglandin. The termination of pseudopregnancy in bilaterally hysterectomized rats by PMSG and its reversal by indomethacin revealed that the inhibition of luteal function by PMSG does not require the presence of a uterus.

Abortifacient Agents↗
PubMedDate not supplied

Peripheral laser angioplasty with pulsed dye laser and ball-tipped optical fibres.

Laser angioplasty with the pulsed dye laser and integral ball-tipped optical fibres was used for primary treatment of occlusive femoropopliteal vascular disease in 26 limbs of 24 patients, all of whom warranted operative intervention. 19 had "critical ischaemia", 8 had pedal ulceration, and 4 had distal gangrene. The delivery device consisted of the laser fibre loaded retrogradely into a standard 6 mm balloon angioplasty catheter, and was introduced through a common femoral artery cutdown in an attempt to recanalise femoropopliteal occlusions of a mean length of 21 cm (range 3-49). Angiographic recanalisation was achieved with a mean energy of 250 J (range 38-727 J) in 23 of the 26 limbs; in each case the channel created by the laser fibre was augmented by balloon angioplasty. Technical failure occurred in 3 patients, due to wall dissection, persistent side-branch entry, and incomplete lesion penetration, respectively. Acute occlusion within 48 h occurred in 2 diabetic patients with very poor run-off and distal gangrene, and early failure occurred in another patient due to inadequate balloon dilatation. 1 patient with segmental tibial disease below a technically successful recanalisation did not show clinical improvement. Several patients had coexisting coronary artery disease, 3 of whom died of myocardial infarction--all with patent femoropopliteal vessels. In the 21 survivors, 14 vessels remained patent at a median of 7 months' follow-up.

Aged↗
PubMedDate not supplied

Summated chemotherapy dose-intensity versus loco-regional response in locally advanced breast cancer: its possible implications.

BACKGROUND: Summated dose-intensity (SDI) of chemotherapy regimen could influence the outcome in malignancies. AIMS: To evaluate the implication of SDI and identify key drugs for loco-regional response in locally advanced breast cancer (LABC). SETTINGS AND DESIGN: This retrospective study was based on audit of records of LABC patients who had received neoadjuvant chemotherapy (NACT). MATERIAL AND METHODS: Actual unit dose-intensity (UDI) of each drug and corresponding SDI of every doxorubicin (n=116 cycles) or non-doxorubicin (n=110 cycles) based NACT received by 42 patients of LABC were summated. Cumulative dose-intensity (CDI) for individual drugs and cumulative SDI (CSDI) for the entire course of NACT were estimated and correlated with quantum of primary tumor, axillary and supraclavicular nodal responses. STATISTICAL ANALYSIS USED: Two-sided chi-square, t-test, step-wise regression was used. RESULTS: Dose-response curve between CSDI and corresponding responses for both primary and lymph nodes were sigmoid in shape for both doxorubicin or non-doxorubicin based NACT. Curves were best fitted using a cubic fit for all patients (r2 = 0.82, 0.84 and 0.93 for primary tumor, axillary and supraclavicular lymph nodes respectively). CSDI emerged as an important prognosticators for both primary (P<0.001) and nodal (P<0.001) responses. Individually, CDI of 5-fluorouracil for primary (P<0.001), CDIs of doxorubicin (P<0.001) and methotrexate (P=0.006) for axillary nodes and CDI of cyclophosphamide (P=0.001) for supraclavicular nodes were significant. CONCLUSIONS: Loco-regional responses in LABC are dependent on CSDI of NACT regimen. Drugs for high-dose intensification protocols could be identified and chosen based on the impact of CDI of individual drugs in NACT.

Adult↗
PubMedDate not supplied

Tumor regression dynamics with external radiotherapy in cancer cervix and its implications.

BACKGROUND: To study the external radiotherapy (EXTRT) regression patterns in cancer of the cervix. AIMS: Evaluate EXTRT tumor regression doses (TRD) for 50% (TRD50), 80% response (TRD80), normalized dose response gradient (g50) and slope (slope50) with clinical outcome. SETTINGS AND DESIGN: Patients, treated solely with radiotherapy and enrolled for other prospective studies having weekly tumor regressions recorded were considered. MATERIAL AND METHODS: Seventy-seven patients received 50Gy of EXTRT at 2 Gy/fraction followed by 18Gy of high-dose rate intracavitary brachytherapy at 6 Gy/fraction. Loco-regional regressions were assessed clinically at weekly intervals during EXTRT to generate EXTRT dose-response curves. STATISTICAL ANALYSIS USED: Student's t test, logistic regression, Kaplan Meier and Cox's proportional hazard model. Scatter plots were fitted using cubic fit. RESULTS: Age (P=0.052) and absence or presence of gross residual tumor (AGRT and PGRT respectively) following EXTRT (P<0.001) were the only determinants for complete response (CR) at 1 month following completion of radiotherapy. EXTRT tumor regression sigmoid curves obtained for various patient characteristics differed only for those with AGRT and PGRT with differences in TRD50, (P<0.001); TRD80 (P<0.001) and slope50 (P=0.001). Response status to EXTRT was a prognosticator for loco-regional disease free survival (LDFS) (AGRT vs. PGRT; P=0.046). On multivariate analysis, both TRD50 and TRD80 emerged as significant predictors for tumor status at end of EXTRT while TRD80 was the sole determinant of LDFS. CONCLUSION: Extent of tumor regression to EXTRT is an important predictor for treatment outcome in cancer cervix as evident from TRD50 and TRD80 values of EXTRT tumor regression curves.

Adult↗
PubMedDate not supplied

Some host factors and seasonal variations in the fatal road traffic accidents occurring in eastern suburban Calcutta.

An extensive study of road traffic accident cases occurring within eastern suburban Calcutta during April 1992 to March 1993 was done. Of which 276 fatal cases having minimum medical aids were taken into consideration to avoid erroneous interpretation. Male pedestrians of age group of 50 years and above were mostly involved during the time period of 5 A.M. to 12 Noon. Fatal Accidents mostly occurred during winter and on the broader roads (Highways) and in majority of cases victims were at fault.

Accidents, Traffic↗