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Biomedical subjects

R Naidu

Publications and source records attributed to R Naidu.

42 records · Page 3Linked to original sources

Serial serum protein determinations in scoliotic children treated by spine fusion and autotransfusion.

In a longitudinal study, serum protein levels were determined by more than 1200 radial immunodiffusion assays in fifty pediatric scoliotic patients whose blood replacement during spine fusion was provided by predeposition autotransfusion. Several serial samples of serum were obtained at intervals from the time of admission through surgery and discharge and they were examined for eight serum proteins: IgG, IgA, IgM, albumin, transferrin, C3c (B1A globulin), beta-lipoprotein, and alpha2-macroglobulin. The results indicated that neither the three phlebotomies performed to obtain predeposition autologuus blood for reinfusion nor the loss of blood during surgery resulted in significant alteration of any of the serum protein levels at the sampling times tested. The greatest decreases in the serum concentrations of all eight proteins were observed during the early postoperative recovery period.

Adolescent↗

Alterations of clotting factors and platelets during hemofiltration.

The influence of hemofiltration on the number of platelets and on coagulation factors was investigated in patients with chronic renal insufficiency. These investigations were done on 12 patients during 22 treatments with hemofiltration. Blood samples were taken before hemofiltration, 10, 30 and 120 minutes after the beginning of the treatment and at the end of hemofiltration. In comparison to the original values we found a loss of platelets, a small decrease in the concentration of fibrinogen and a small increase in the fibrin monomer complex, plasminogen, antithrombin III, alpha1-antitrypsin and in alpha2-macroglobulin. The thrombin time, the partial thromboplastin time and Quick's test showed that the blood of these patients contained sufficient hepatin. Use of fibrin plates (Astrup) showed no signs of fibrinolytic activity. Compared to the results, which were obtained some years ago during hemodialysis, we found a smaller extent of alterations of blood coagulation factors and number of platelets.

Antithrombins↗

Chemistry of inorganic arsenic in soils: II. Effect of phosphorus, sodium, and calcium on arsenic sorption.

There are more than 10000 arsenic (As) contaminated sites in Australia. The ability of soils at these contaminated sites to sorb As is highly variable and appreciable amounts of As have been recorded in the subsurface soils. The potential risk of surface and ground water contamination by As at these sites is a major environmental concern. Factors that influence adsorption capacity of soils influence the bioavailability and subsequent mobility of As in soils. In the present study we investigated the effect of PO4(3-) and Na+ and Ca2+ on the sorption of AsV and AsIII by an Oxisol, a Vertisol, and two Alfisols. The presence of P (0.16 mmol L(-1)) greatly decreased AsV sorption by soils containing low amounts of Fe oxides (<100 mmol kg(-1)), indicating competitive adsorption between P and AsV for sorption sites. In contrast, the presence of a similar amount of P had little effect on the amount of AsV adsorbed by soils with high Fe content (>800 mmol kg(-1)). However, AsV sorption substantially decreased from 0.63 to 0.37 mmol kg(-1) as P concentration was increased from 0.16 to 3.2 mmol L(-1) in selected soils. This suggests increased competition between P and AsV for soil sorption sites, through either the higher affinity or the effect of mass action of the increasing concentration of P in solution. A similar effect of P on AsIII sorption was observed in the low sorbing Alfisol and high affinity Oxisol. However, the amount of AsIII sorbed by the Oxisol was much greater than the Alfisol for all treatments. The presence of Ca2+ increased the amount of AsV sorbed compared with that of Na+ and was manifested through changes in the surface charge characteristics of the soils. A similar trend in AsIII sorption was recorded with changes in index cation, although the effect was not as marked as recorded for AsV.

Adsorption↗

Immunohistochemical analysis of p53 expression in primary breast carcinomas.

Expression of p53 protein was investigated by immunohistochemical techniques in archival cases of 134 primary breast carcinomas comprising 13 comedo ductal carcinoma in situ (DCIS), 105 invasive ductal carcinomas, 7 contained the comedo DCIS component adjacent to the invasive ductal component, 5 invasive lobular carcinomas, three colloid carcinomas and one medullary carcinoma. Overexpression of p53 gene product was studied to determine the association with clinico-pathological parameters and also its relationship to c-erbB2. Overexpression of p53 protein was observed in 31% (4/13) of comedo DCIS, 37% (39/105) of invasive ductal carcinomas, 57% (4/7) of carcinomas containing both the in situ and invasive lesions and all medullary carcinomas. A significant relationship (p < 0.05) was observed between strong immunoreactivity of p53 protein and absence of estrogen receptor, histological grade and c-erbB2 but not with lymph node metastases or age of patient. These observations suggest that overexpression of p53 protein may play an important role in tumor progression from noninvasive to invasive in some breast carcinomas and may have potential as an indicator for poorer prognosis.

Adult↗