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Biomedical subjects

A Agarwal

Publications and source records attributed to A Agarwal.

At least 307 records · Page 17Linked to original sources
PubMed1995

Effect of cryopreservation on semen quality in patients with testicular cancer.

OBJECTIVES: Current techniques in cryopreservation of human semen substantially decrease sperm quality. In addition, the pregnancy rate using cryopreserved sperm obtained from testicular cancer patients is lower than when sperm from normal fertile men is used. However, it is still unclear whether cryopreserved sperm from these patients is inherently defective or if the sperm loses its motility after thawing. This study was undertaken to assess the effect of cryopreservation on the quality and motion characteristics of semen from patients with testicular cancer before definitive therapy compared with semen from normal volunteers. METHODS: We compared the sperm quality before and after cryopreservation in samples from 34 patients with testicular cancer and 30 normal volunteers who were referred for sperm banking over a 7-year period. The effects of cancer stage and histologic type on various semen parameters were also examined. A computer-assisted semen analysis was performed before and after cryopreservation on each specimen. The nitrogen vapor technique using Test yolk buffer with glycerol as a cryoprotective agent was used for cryopreservation. The motile sperm count and motion characteristics (motility, velocity, linearity, amplitude of the lateral head movement, motility index) were analyzed before and after cryopreservation and compared between the groups. RESULTS: Semen quality did not significantly differ among patients with Stage I, II, or III cancer. However, semen quality tended to be poorer at higher cancer stages. In general, semen quality was better among patients with pure seminomas than with pure embryonal tumors; quality was worst among patients with mixed germ cell tumors. However, 71.4% of patients with mixed tumors presented with Stage III disease, whereas all patients with seminomas presented with Stage I disease. Significant differences were also seen in prefreeze motility (median, 42% [interquartile range, 24 to 51] versus 60.5% [range, 49 to 73]; P = 0.0004) and motile sperm count (6.7 x 10(6)/mL [range, 3.4 to 14.4] versus 50.0 [range, 24.6 to 72.0]; P = 0.0001) in patients compared with controls, respectively. The motile sperm count and percent motility significantly decreased in both patients and controls after cryopreservation (P = 0.0001). However, the percentage decline in motile sperm count and motion characteristics after cryopreservation did not differ significantly between patients and controls (P > 0.01). CONCLUSIONS: We conclude that the effect of cryopreservation on sperm quality in patients with testicular cancer is identical to its effect on sperm from normal fertile men. Differences in values after preservation are explained by poor semen characteristics before freezing; semen quality declines with more extensive disease. Stage I patients also had poorer quality than control subjects. Thus, we recommend that routine sperm banking be encouraged among all patients with testicular cancer before the initiation of specific medical treatment. We also recommend that future efforts be focused on improving the technique of sperm banking.

Adolescent↗
PubMed1995

HIV-2 strikes injecting drug users (IDUs) in India.

Manipur, a north-eastern state of India bordering Myanmar, observed introduction of HIV-1 among fairly large number of IDUs in October 1989, followed by rapid spread within the next 6 months. HIV-2 in injectors was not present until recently, though it was detected from other parts of India in 1991. This communication reports for the first time presence of HIV-2 among young injectors of Manipur. All the HIV-2 infected IDUs were also found to be infected with HIV-1. HIV-2 has affected a large number of people in Africa through heterosexual transmission. It remains to be seen whether HIV-2 spreads rapidly also among the drug-injecting population of Manipur. Observation of the disease progression among HIV-2 infected IDUs will also be of interest.

Acquired Immunodeficiency Syndrome↗
PubMed1995

Induction of heme oxygenase in toxic renal injury: a protective role in cisplatin nephrotoxicity in the rat.

Cellular content of heme is regulated by heme oxygenase, the rate limiting enzyme in the degradation of heme. Induction of heme oxygenase is a protective response in an in vivo model of heme protein mediated renal injury, the glycerol model of acute renal failure. In addition to heme, heme oxygenase is induced by diverse forms of oxidative stress, the functional significance of which is currently unknown. We examined whether heme oxygenase is induced, and the functional significance of such induction, in two in vivo models of oxidant-induced toxic nephropathy, namely, cisplatin and gentamicin nephropathies; nephrotoxicity in these models is not dependent on the delivery of a burden of heme proteins to the kidney as occurs in the glycerol model. We demonstrate induction of heme oxygenase mRNA and protein in the kidney as early as 6 and 12 hours after a single dose of cisplatin (6 mg/kg i.v.). Pretreatment with tin protoporphyrin, a competitive inhibitor of heme oxygenase, led to higher serum creatinine values on days 3 through 5 and lower inulin clearances on day 5; tin protoporphyrin also exacerbated renal injury in this model. Renal hemodynamics studied at day 2 after cisplatin demonstrate reduced renal blood flow rates, increased renal vascular resistance and increased fractional excretion of sodium in rats treated with tin protoporphyrin. Tin protoporphyrin alone had no significant effect on serum creatinine and renal hemodynamics in rats with intact, disease-free kidneys. We confirmed that tin protoporphyrin prevented the increase in heme oxygenase activity induced by cisplatin. Induction of heme oxygenase by cisplatin was associated with increased kidney heme content and ferritin content.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1995

A method of human semen centrifugation to minimize the iatrogenic sperm injuries caused by reactive oxygen species.

Current techniques of sperm preparation for in vitro fertilization or intrauterine insemination require centrifugation of human semen to separate spermatozoa from the seminal plasma. Centrifugation increases reactive oxygen species (ROS) formation in semen. Moreover, high levels of ROS are associated with sperm membrane injury through spontaneous lipid peroxidation, which may alter sperm function. We investigated the relationship between centrifugation variables (time and g-force) and ROS production to establish an optimal centrifugation protocol for sperm preparation techniques. Semen from 38 men (24 patients and 14 normal volunteers) was evaluated for the formation of ROS before centrifugation and after centrifugation at 200 g for 2 or 10 min and after 500 g for 2 or 10 min. The absence of white blood cells in semen which can also produce ROS was determined with the myeloperoxidase technique (Endtz test). All specimens were negative (< 1 x 10(6)/ml) by the Endtz test. The formation of ROS was measured by chemiluminescence. ROS formation was regarded as high (positive) when the chemiluminescence response was at least 10 x 10(4) counted photons/min (cpm). The sperm concentration in each sample was adjusted to 15-20 x 10(6) cells/ml before analysis. Eight specimens (7 patients and 1 donor) exhibited high levels of ROS before centrifugation. All 8 showed further, significant increases in ROS formation regardless of g-force or time. The increase in ROS was significantly less when semen was centrifuged for 2 as compared to 10 min (p < 0.001). Six specimens previously ROS-negative became ROS-positive after centrifugation for 10 min at 200 and 500g. We conclude that the time of centrifugation is more important than g-force for inducing ROS formation in semen. Based on these results, we recommend a shorter centrifugation period in the preparation of sperm for assisted reproductive techniques.

Centrifugation↗
PubMed1995

Recurrent hemolytic uremic syndrome in an adult renal allograft recipient: current concepts and management.

Acute renal insufficiency in the setting of hemolysis and thrombocytopenia, a triad that constitutes adult or pediatric hemolytic uremic syndrome, can be associated with or triggered by diverse conditions such as verocytotoxin-producing Escherichia coli, viral infections, pregnancy, malignant hypertension, scleroderma, renal radiation, allograft rejection, lupus erythematosus, and assorted medications such as mitomycin C, cyclosporine, and oral contraceptives. Recurrent and de novo hemolytic uremic syndrome occur after renal transplantation. Relapses are also common and probably reflect incomplete resolution of the initial episode. The major differential diagnoses of hemolytic uremic syndrome in the renal allograft include acute vascular rejection, cyclosporine, FK506 or antilymphocyte antibody nephrotoxicity, and malignant hypertension, all of which may display overlapping clinical and histologic features with primary hemolytic uremic syndrome; in such instances, the exact diagnosis may be quite difficult. It is possible that the risk of recurrence may be reduced by proper timing of transplantation and suitable choice of immunosuppressive agents. Intensive plasmapheresis in conjunction with fresh frozen plasma and supportive management of renal failure may lessen mortality and morbidity even in recurrent hemolytic uremic syndrome after transplantation.

Adult↗
PubMed1995

Biomechanical properties of hip cartilage in experimental animal models.

The material properties of normal adult articular cartilage were determined in the femoral head and acetabulum of baboons, dogs, and bovines, and were compared with those of normal human hip cartilage. In situ creep and recovery indentation experiments were performed using an automated creep indentation apparatus. To curvefit the entire creep curve, a numerical algorithm based on biphasic finite element methods and nonlinear optimization was developed. This effort represents the first successful use of 100% of the creep indentation curve to obtain the mechanical properties of normal articular cartilage. The results show that material properties of articular cartilage exhibit significant topographical variations in the femoral head and acetabulum, and between these two bone structures. Furthermore, significant differences exist in the mechanical properties of hip cartilage among the 4 species. Specifically, in all species the smallest aggregate modulus is found in the inferior aspect of the femoral head. Among all species, human hip cartilage is the stiffest in all test sites; bovine tissue is the softest. Human tissue has the smallest Poisson's ratio and permeability in all test sites. The aggregate modulus of human hip cartilage is closely resembled by that of baboon hip cartilage. Anatomically, canine and baboon hips exhibit similar characteristics to the human hip joint; the bovine hip joint is distinctly different. Based on this study's data, the baboon represents the most appropriate animal model of normal human hip articular cartilage.

Animals↗
PubMed1995

Optimum abstinence time for cryopreservation of semen in cancer patients.

Although an abstinence period of 48 to 72 hours is the most commonly prescribed interval for diagnostic semen analysis, to our knowledge the association between the abstinence period and sperm quality after cryopreservation has not been identified. Patients with a malignant disease who are consulting for semen banking most often require urgent therapy. Consequently, defining the shortest abstinence period that allows for frequent semen collection within a limited interval and the best post-thaw sperm quality is necessary. We investigated the relationship between abstinence period, and the pre-freeze and post-thaw motility variables in semen specimens obtained from cancer patients for sperm banking. Samples collected from 95 patients were divided according to abstinence period: group 1-15 patients at 24 to less than 48 hours, group 2-53 at 48 to less than 72 hours and group 3-27 at more than 72 hours. Pre-freeze and post-thaw motile sperm count and motion variables (motility, velocity, linearity, amplitude of lateral head movement and motility index), and percentage decrease in sperm variables after cryopreservation were analyzed. Semen volume, the pre-freeze and post-thaw motile sperm count, motion parameters and the percentage decrease in semen variables did not differ significantly among the groups. We conclude that semen collection for cryopreservation after 24 to less than 48 hours of abstinence results in post-thaw quality comparable to that after an abstinence of 48 to less than 72 hours or longer. Thus, an abstinence period of 24 to less than 48 hours can be recommended for sperm banking in cancer patients.

Cryopreservation↗
PubMed1995

Carcinoma in Graves' disease.

Association of thyroid carcinoma in thyrotoxicosis is uncommon. Preoperative diagnosis of such association is difficult. In a retrospective study of 49 operated cases of Graves' disease (GD) such an association was found in four patients. Findings of a palpable nodule, calcification and a cold nodule on scanning in Graves' disease should increase suspicion for such an association and a frozen section study should be underken in all these cases during surgery to exclude possible co-existing malignancy.

Adenocarcinoma, Follicular↗
PubMed1995

Effect of age on P300 wave.

30 healthy elderly males (mean age 77.4 +/- 4.3 yrs) were subjects in this study. Equal number of young males (mean age 22 +/- 3.5 years) and middle aged subjects (mean age 46 +/- 3.2 years) served as control. P300 wave was estimated using a Neuropack 4 model of Nihon Kohden EMG machine. We observed a significantly increased latency, poorly defined and non reproducible P300 wave in 90% old subjects while in young the latency was in normal limits and the wave was well defined and reproducible. We presume P300 could serve as a future potential marker of the neurophysiological basis of aging.

Acoustic Stimulation↗
PubMed1994

Does curriculum make a difference? A comparison of family physicians with and without rheumatology training during residency.

OBJECTIVE: To assess the long-term effect of an extensive rheumatology curriculum on graduates of family practice residencies. DESIGN: Cohort analytic study using a mailed survey and a multiple-choice test based on clinical vignettes that were administered 3 to 7 years after graduation from residency training. PARTICIPANTS: Practicing family physicians who had graduated from a community hospital family practice residency with an extensive rheumatology curriculum (trained) were compared with graduates from a similar program without specific rheumatology training (untrained). MAIN OUTCOME MEASURES: Total test scores, results of individual test questions, practice style, and attitudes toward rheumatology training and practice. RESULTS: We received 39 (85%) responses from 46 potential respondents in the trained group and 25 (89%) responses from 28 potential respondents in the untrained group. Physicians in the two groups had similar backgrounds and practice styles. The trained physicians scored higher on the multiple-choice test (mean +/- SD, 25 +/- 5 vs 22 +/- 6; P < .03). The clinical significance of these differences is a matter of individual interpretation. One hundred percent of the trained physicians believed that the quality of their rheumatology training was good to excellent compared with 25% of the untrained physicians. Seventy-six percent of the untrained physicians wished that they knew more about rheumatology. No variables other than rheumatology training accounted for the differences between the two groups. CONCLUSIONS: The difference in rheumatology knowledge, evident during and soon after residency between trained and untrained physicians, persists for 3 to 7 years.

Adult↗
PubMed1994

Comparative study of the intrinsic mechanical properties of the human acetabular and femoral head cartilage.

Biphasic creep indentation methodology and an automated indentation apparatus were used to measure the aggregate modulus, Poisson's ratio, permeability, thickness, creep and recovery equilibrium times, and percentage of recovery of normal articular cartilage in 10 human hip joints. These properties were mapped regionally to examine the mechanical factors involved in the development of site-specific degenerative lesions in the acetabulum and femoral head. The results indicate that there are significant differences between these properties regionally in the acetabulum and femoral head and between the two anatomical structures. Specifically, it was found that cartilage in the superomedial aspect of the femoral head has a 41% larger aggregate modulus than its anatomically corresponding articulating surface in the acetabulum. In addition, the superomedial aspect of the femoral head has the greatest aggregate modulus (1.816 MPa) within the hip joint. During sitting, the inferior portion of the femoral head is in contact with the anterior acetabulum, and the anterior acetabulum has a 53% greater aggregate modulus than the inferior femoral head. This area below the fovea on the femoral head has the least aggregate modulus (0.814 MPa) within the hip joint. These mismatches in the compressive modulus of opposing articulating surfaces may contribute to degeneration of cartilage in the superomedial acetabulum and the inferior femoral head. Our findings support the clinical observation that these areas are frequent sites of early degeneration.

Acetabulum↗
PubMed1994

Nicardipine and verapamil attenuate the pressor response to laryngoscopy and intubation.

In a prospective, double-blind study, we compared the efficacy of iv nicardipine hydrochloride and verapamil hydrochloride in attenuating the cardiovascular responses to laryngoscopy and tracheal intubation, in 45 patients undergoing elective surgery with general anaesthesia. Patients were allocated randomly to one of three groups of 15 patients. Patients in Group I received saline while those in Groups II and III received nicardipine hydrochloride, 0.03 mg.kg-1 or verapamil hydrochloride, 0.1 mg.kg-1 iv three minutes before laryngoscopy and intubation. Patients in Group I showed the greatest increase in SBP 25.4 +/- 2.2 2.2 mmHg and HR 35.7 +/- 3.8 beats.min-1 at one minute after intubation (P < 0.001), and these changes persisted throughout the study period albeit with decreasing magnitude. After drug administration, patients in Groups II and III demonstrated increases in HR of 26 +/- 2.4 and 15.1 +/- 2.2 beats.min-1 and decreases in SBP of 24.8 +/- 2.0 and 18.8 +/- 2.4 mmHg respectively (P < 0.001). It is concluded that nicardipine and verapamil are effective in attenuating pressor responses to laryngoscopy and intubation but did not control the tachycardia.

Adult↗