PubMed Health⌕ Search

Biomedical subjects

C Reddy

Publications and source records attributed to C Reddy.

13 recordsLinked to original sources
PubMed2005

Time and PSA threshold model prognosticates long-term overall and disease-specific survival in prostate cancer patients as early as 3 months after external beam radiation therapy.

The specific aim of this analysis was to evaluate the capability of a time and prostate-specific antigen (PSA) threshold model to prognosticate overall survival (OS) and disease-specific survival (DSS) based on early PSA kinetics after radiotherapy for prostate cancer by retrospective review of outcomes in 918 patients. Crossing below analyzed PSA thresholds at specific defined time points reduced disease-specific death hazard ratios to relative to the cohort above threshold. The time and PSA threshold model demonstrates the ability to prognosticate OS and DSS as early as 3 months post-radiotherapy for prostate cancer.

Aged↗
PubMed2001

Calibration frequency of dose--area product meters.

Calibration of patient dose monitoring devices in diagnostic radiology has become increasingly important in the light of new legislation that requires monitoring of patient dose against local and national diagnostic reference levels. An investigation was conducted into the long-term stability of 41 dose-area product (DAP) meters over a period of approximately 5 years, to assess the suitability of an annual calibration regimen. For DAP meters fitted to overcouch X-ray tubes, 77% of calibrations were within 10%, whilst for undercouch tubes only 50% of calibrations were within 10%. These findings suggest that annual calibration may be too infrequent. Suitable calibration frequencies for different clinical workloads are discussed.

Calibration↗
PubMed2000

No difference in biochemical failure rates with or without pelvic lymph node dissection during radical prostatectomy in low-risk patients.

OBJECTIVES: To detect the short-term differences in biochemical relapse-free rates between patients with and without pelvic lymph node dissection (PLND). Recently, a trend has begun to omit PLND in patients undergoing radical prostatectomy considered at low risk of pelvic lymph node metastases. METHODS: The records of 1152 consecutive radical prostatectomy cases were reviewed. A total of 575 patients with favorable tumor characteristics (prostate-specific antigen [PSA] 10 ng/mL or less, Gleason score 6 or less, and clinical Stage T1 or T2) who were not receiving adjuvant or neoadjuvant therapy were divided into two groups according to whether PLND was performed (PLND group, n = 372) or omitted (no PLND group, n = 203). Proportional hazards were used to analyze the effect of age, race, family history, stage, biopsy Gleason score, initial PSA, PLND, and pathologic findings on the likelihood of biochemical failure. Biochemical failure-free survival for each group was estimated by Kaplan-Meier analysis. The mean follow-up was 38 months (range 1 to 141). RESULTS: The actuarial 4-year biochemical relapse-free rate for the PLND versus no PLND groups was 91% and 97%, respectively (P = 0.16). On multivariate analysis, PLND was not an independent predictor of outcome (P = 0.24). CONCLUSIONS: The results of our study indicate that the omission of PLND in patients with favorable tumor characteristics does not adversely affect biochemical relapse rates.

Aged↗
PubMed1990

Pathologic changes in the exorbital lacrimal gland of the vitamin A-deficient rat.

Histologic changes in lacrimal glands of vitamin A-deficient (A-) and pair-fed control rats were compared. In A- lacrimal glands, secretory granules were strikingly diminished, and rough endoplasmic reticulum appeared somewhat atrophic. Nuclei of acinar cells were hyperchromatic and pleomorphic. Using alcian blue-PAS, no positive staining was present in acini of A- lacrimal glands, whereas in controls apical portions of acini were intensely stained. Thus, lacrimal tissues of A- rats were thought to be poorly differentiated as a glandular epithelium. When A- rats were supplemented with retinyl acetate, secretory granules reappeared, rough endoplasmic reticulum cisternae greatly dilated, and mitochondria proliferated, indicating accelerated secretory activity. Resupply of vitamin A can induce glandular differentiation in A- lacrimal tissues. Tear volume was not decreased in A- rats compared with pair-fed controls. Regression of secretory organelles in A- lacrimal tissues may lead to a decrease in protein and mucoprotein secretion and subsequent changes in tear composition.

Animals↗
PubMed1988

Pathogenesis of experimental lipid keratopathy. An ultrastructural study of an animal model system.

The histology and ultrastructure of experimental lipid keratopathy were studied in hypercholesterolemic rabbits in which the insertion of corneal sutures induced vascularization and subsequent lipid deposition in the anterior stroma. Lipid accumulated in the keratocytes, the pericytes and occasionally in the endothelial cells of the capillaries. The lipid-laden keratocytes were concentrated in the region of the capillaries. No lipid was seen in the control rabbits. In the hypercholesterolemic rabbit with sutures, intracellular lipid in the keratocytes was present largely in nonmembrane-limited droplets with smaller amounts of membrane-limited cholesterol crystals and rare numbers of myelin figures. In addition, large, lipid-engorged spherical cells were present. The numerous phagolysosomes seen ultrastructurally suggest that some of these cells probably represent macrophages. Keratocytes and the large, spherical lipid-engorged cells show focal degenerative changes, including pyknotic nuclei, cytoplasmic coagulation and membrane loss, leaving extracellular mixed accumulations of lipid and cytoplasmic organelles. Small numbers of lymphocytes and plasmacytoid cells were present. No corneal lipid was seen in animals with normocholesterolemia, with or without sutures. In hypercholesterolemic animals, a few lipid-laden keratocytes without macrophages were identified even in the absence of vessels. These morphologic studies support the hypothesis that the accumulation of the corneal lipid in this animal model of lipid keratopathy is the result of increased lysosomal uptake of lipid, probably as low density lipoprotein, from the extracellular space by the keratocytes. The rate of metabolism of this lipid is insufficient to clear the cells of the lipid and the subsequent lipid inspissation results in keratocyte death, leading to macrophage accumulation of lipid and free lipid in the stroma.

Animals↗
PubMed1987

Pathogenesis of experimental lipid keratopathy: corneal and plasma lipids.

Corneal and plasma lipids were studied in a rabbit model to gain insight into the pathogenesis of secondary lipid keratopathy. Rabbits were divided into four groups in which a high cholesterol diet and corneal suture placement were varied to produce lipid keratopathy. In rabbits with lipid keratopathy, quantitative thin layer chromatography revealed that cholesterol esters comprised most of the deposited lipid, with free cholesterol being deposited as well. The ratio of accumulated cholesterol ester to free cholesterol corresponded closely to the same ratio in hypercholesterolemic plasma total low and very low density lipoprotein (TLDL). Furthermore, gas chromatography showed that the cholesterol ester composition in the corneas with lipid keratopathy resembled that seen in hypercholesterolemic plasma TLDL but was different from the pattern observed in the normal cornea. These studies suggest that the direct source of the deposited cholesterol ester is primarily the plasma TLDL. Since phospholipids and triglycerides did not show a significant increase in the experimental corneas, they are presumably metabolized by the keratocytes after the uptake of TLDL. However, the amount of cholesterol ester carried by the lipoprotein exceeds the capacity of the cell for use and excretion and the lipid accumulates in the cornea.

Animals↗
PubMed1978

Systemic lupus erythematosus presenting as chorea.

A child presenting with chorea developed the full clinical and laboratory findings of systemic lupus erythematosus after hospitalisation. He responded dramatically to haloperidol. 6 months after diagnosis he began to manifest renal involvement.

Child↗
PubMedDate not supplied

Acute lead poisoning with eosinophilic meningoencephalitis in calves on a farm receiving land application of sewage sludge.

A total of 3 cases of acute lead poisoning in calves was confirmed by atomic absorption spectrophotometric analysis of biological samples, presence of an acute lead exposure source, clinical signs of impaired vision in one case and eosinophilic meningoencephalitis in another case. One of two other calves which died approximately 2 months earlier had nervous signs and it is likely that they also had lead poisoning. Dams of two of the cases did not have elevated lead levels. Municipal sewage sludge had been applied to most fields on the farm during the preceding 5 year period. There had been approximately a doubling of the lead content in the soil; however, the foodstuffs produced on the farm had low lead concentrations. The extremely high lead levels in the abomasal contents and feces of calves eliminated sludge as the source of the lead in this acute poisoning episode. The contents of oil filters, accessible to calves but not to adult cattle, had lead levels as high as 26,922 micrograms/g and was the most likely lead source responsible for this lead intoxication. It appears that the manifestation of eosinophilic meningoencephalitis in lead poisoning cases may occur in young calves as well as in cows and in acute as well as in chronic intoxications.

Acute Disease↗