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Biomedical subjects

J Skurnick

Publications and source records attributed to J Skurnick.

24 records · Page 2Linked to original sources
PubMed1992

Controlled micromanipulation of human sperm in three dimensions with an infrared laser optical trap: effect on sperm velocity.

Individual human sperm can be micromanipulated in three dimensions using a 1.06 microns Nd:YAG laser trap. Single sperm swimming with velocities in the range of 65 to 85 microns/sec can be trapped with 40 mW of power through 120 seconds without a deleterious effect on velocity. Even though it will be necessary to further evaluate the effects of laser light on specific functions of sperm, our data suggest that decreasing the time of manipulation to a minimum will increase the safety of the micromanipulation procedures. Laser traps may play a role in assisted reproductive technology by facilitating the selective transport of individual sperm.

Analysis of Variance↗
PubMed1991

Ovarian control of pituitary hormone secretion in early human pregnancy.

To determine the influence of ovarian relaxin on the secretion of pituitary GH and PRL in vivo, we evaluated circulating serum hormone levels in 17 pregnant patients with functional corpora lutea (group I) and compared them to levels in 10 patients with premature ovarian failure (POF; group II) who became pregnant with egg donation and did not have corpora lutea. Group II patients had exogenous hormonal support. Serum relaxin (RLX), GH, PRL, estradiol (E2), and progesterone levels were measured weekly by RIA from weeks 4-8 of pregnancy. Analysis of variance and covariance were used to determine hormonal relationships. Serum RLX was present in the natural pregnancy group, with a mean of 1.94 micrograms/L over the study period. Serum RLX was undetectable in the POF patients (less than 0.16 micrograms/L). No significant difference in PRL or progesterone levels between the two groups was noted. E2 levels showed an upward trend in both groups with time and were significantly higher in patients of the POF group than in group I women (P = 0.001). GH levels were significantly higher in the natural cycle patients (P = 0.02) despite lower E2 levels. These data provide additional support for the concept that RLX production in early pregnancy originates from the corpus luteum. They suggest that a luteal product, probably RLX, stimulates GH secretion in early pregnancy. This is a previously undescribed role for RLX in pituitary physiology during human pregnancy.

Adult↗
PubMed1988

Blood pressure elevation in young dogs during low-level lead poisoning.

Clinical and experimental studies suggest an association between low-level lead exposure and hypertension. This association was investigated in six 3-month-old dogs who were randomly paired with their littermates. The daily oral dose of lead acetate was 1.0 mg Pb/kg body wt for 5 months; the controls received equimolar sodium acetate. Blood pressure was measured indirectly without anesthesia and was similar in the two groups at the start of the study. The mean blood pressure was higher in the lead-exposed group at every follow-up, from 10 days to 20 weeks. This treatment group difference in profiles was statistically significant (repeated-measures ANOVA, p = 0.0048). The final mean blood pressures were 120 +/- 6.4 (x +/- SE) vs 108 +/- 1.5 mm Hg. At 4 weeks the plasma renin activity was higher in the lead-exposed group: 3.4 +/- 0.25 vs 1.2 +/- 0.15 ng/ml/hr. The difference decreased during the study but the elevated trend persisted (repeated-measures ANOVA, p = 0.014). Lead exposure did not alter renal functions or extracellular fluid volume. This study shows that low-level lead intake in young dogs can cause an early increase in blood pressure which persists during ongoing exposure and which is associated with a small increase in the activity of the renin-angiotensin system.

Analysis of Variance↗
PubMed1987

Effects of a geriatric clinic on functional health and well-being of elders.

Using a prospective, randomized design, the effects on self-reported functional health and well being of 18 months of primary outpatient care in a geriatric clinic staffed by a multidisciplinary team with geriatric training were compared with traditional Veterans Administration care for 205 elders. Significantly less decline in functional health was found for the geriatric clinic participants on the total Sickness Impact Profile (SIP) (M = .18 vs. 3.12, p = .029) and its physical dimension (M = .28 vs. 4.39, p = .011), but not for the psychosocial dimension of the SIP, life satisfaction, depression, self-rated health, or affect balance. In addition, twice as many geriatrics clinic patients died (p = .10) during the study. Further clarification of the impact of a multidisciplinary geriatrics clinic on health outcomes and cost in VA and other settings are needed prior to recommending that this model of geriatric health care be adopted.

Aged↗
PubMedDate not supplied

Presence and quantification of macrophages in squamous cell carcinoma of the cervix.

Cervical cancer is a major cause of morbidity and mortality in women. The presence of macrophages as well as other inflammatory cells has been noted in many of these tumors. Intratumoral macrophages/monocytes induce anergy to cytokine therapy and cause apoptosis in natural killer(NK) and T cells. The aim of this study was to better evaluate and quantify the presence of macrophages in these tumors. Twenty-four cases of squamous cell carcinoma of the cervix seen at our institution were evaluated. Sections were stained with CD68, a marker for macrophages. Staining was graded microscopically by two reviewers together on a scale of 0-4+, with 4+ representing the greatest number of positive cells. Image analysis was conducted to quantify the percent area stained in a given lesion. For each lesion, 10 fields were evaluated, and a mean percentage area stained was calculated. 4+ staining was observed in five cases, 3+ in zero cases, 2+ in three cases, 1+ in six cases, 1-2+ in one case, and nine cases were negative. Image analysis results correlated well with the light microscopic scoring. Presence of a prominent infiltrate of macrophages did not correlate with tumor grade or with histologic lymph node status, but showed a strong negative correlation with tumor stage. Some squamous cell carcinomas of the cervix show a prominent macrophage component in the tumor-associated inflammatory infiltrate. The presence of this prominent infiltration of macrophages did not correlate with tumor grade or lymph node status, but showed a strong negative correlation with tumor stage. The results suggest that immunotherapy may have a potential role in the treatment of cervical carcinoma. Computerized image analysis appears to be a valid measure to assess macrophage counts in such lesions.

Adult↗