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Biomedical subjects

B Lunenfeld

Publications and source records attributed to B Lunenfeld.

At least 163 records · Page 9Linked to original sources
PubMed1980

Morphological characterization of abnormal human spermatozoa using transmission electron microscopy.

A morphological analysis of ejaculated human abnormal spermatozoa is presented. Eighteen different malformations are characterized, based on (a) the cell's organelle where they appeared, (b) the possible developmental stage when they occurred, and (c) the possible mechanism responsible for a specific appearance. The forces that govern the shaping of the spermatozoan head are described in detail. The possible mechanism responsible for chromatin subcondensation, acrosome malformation, kinked tail forms, and mitochondrial malformations are discussed.

Acrosome↗
PubMed1980

Hormonal responses to nasal application of synthetic gonadotropin-releasing hormone in amenorrheic patients pretreated with gonadotropins.

Synthetic gonadotropin-releasing hormone (GnRH) in the form of nasal drops was self-administered by five amenorrheic patients in an attempt to assess its therapeutic value in anovulatory infertility. After follicular maturation had been induced with human menopausal gonadotropins (HMG), a total daily dose of 7.5 mg of GnRH in the form of nasal drops was self-administered at 2-hour intervals for 6 hours on 3 consecutive days. In four patients, plasma luteinizing hormone (LH) levels were significantly elevated over a period of at least 8 hours. In three of these patients, in addition, there was a definite upward shift in the basal body temperature (BBT) curve, and uterine bleeding occurred 6 to 9 days after the first dose of GnRH. In the fourth patient, ovulation was induced as indicated by a biphasic BBT curve, a plasma progesterone level of 13 ng/ml, and a luteal phase of 15 days. In the remaining patient, there was a borderline LH response and no clinical response. It is concluded that GnRH, in the form of nasal drops, is effective in eliciting and maintaining elevated plasma LH levels in patients in whom follicular maturation has been induced with HMG. By obtaining ovulatory LH levels, such a regimen can lead to ovulation. In addition intranasal self-administration of GnRH is convenient and may provide an alternative route of administration for long-term therapy with this hormone.

Administration, Intranasal↗
PubMed1980

Studies on polyspermia.

Thirty-one couples in whom the only apparent abnormality was polyspermia in the male partner were studied in light of a suggested new definition of polyspermia. The rate of infertility was 22.5% versus 17.6% in a control group of couples with no apparent abnormalities; the difference was not statistically significant. The spontaneous abortion rate was 25.5% versus 9.7% in the controls (P less than 0.05). Semen analysis of the men showed signifcantly low fructose levels and high percentages of necrospermia and agglutination compared to controls. Various hypotheses for the etiology of polyspermia are discussed.

Fructose↗
PubMed1979

Breast milk thyroxine and not cow's milk may mitigate and delay the clinical picture of neonatal hypothyroidism.

Thyroxine concentration was measured in human milk and Cow's milk products by a specific radioimmunoassay. The mean (+/- S.E.M.) milk T4 concentration during the first 5 days postpartum was 0.7 +/- 0.3 microgram/dl (n = 11). The mean T4 concentration between 6-49 days postpartum rose to 3.1 +/- 0.2 microgram/dl (n = 108), falling after 50 days to a mean of 1.4 +/- 0.2 microgram/dl (n = 39). The mean (+/- S.E.M.) T3 concentration in breast milk in the first 50 days postpartum was 386 +/- 17 ng/dl (n = 56). T4 concentration in cow's milk products was less than 0.3 microgram/dl. Thyroxine concentration in 24 hours breast milk collection ranged from 0.7 to 7.7 microgram/dl and the total T4 in this milk ranged from 0.7 to 28 microgram/day. These data suggest that milk of human but not bovine origin may provide a significant exogenous source of T4 to the premature infant. This amount of exogenous T4 which is insufficient in preventing the proceeding of neonatal hypothyroidism, may delay the clinical recognition of this disorder. This once again emphasized the importance of early screening for neonatal hypothyroidism.

Animals↗
PubMed1979

Congenital hypoaldosteronism. Thirteen year follow-up in identical twins.

Identical male twins suffering from congenital hypoaldosteronism due to a rare adrenal enzyme deficiency between corticosterone and aldosterone were followed-upfrom birth till their present age of 13 years. The symptoms of salt loss disappeared and normal growth rate resumed following treatment with DOCA and salt supplementation. Discontinuation of mineralocorticoid administration at the age of 7 years resulted during a 5-year period in a marked decline in their growth rate. Labororatory data revealed a persistent, albeit less pronounced, metabolic impairment. Mineralocorticoid administration was resumed and the twins entered normal puberty and increased their growth rate, emphasizing their need for continued mineralocorticoid administration to maintain adequate growth rate and development.

Adrenal Cortex Hormones↗
PubMed1979

Intra-amniotic thyroxine (T4) absorption by the premature human foetus.

We reported previously on the beneficial influence of intra-amniotic T4 injection in accelerating human foetal lung maturity. Twenty-four h after T4 (250 microgram) intra-amniotic injection, the mean cord serum T4 concentration in 13 premature newborns was 17 +/- 2.1 microgram/100 ml, while the T4 concentration in a matched group was only 11.6 +/- 0.9 microgram/100 ml: in 5 of the infants who received intra-amniotic thyroxine T4 was measured 12 h post-partum and rose from 16.1 +/- 1.8 to 24.3 +/- 2.6 microgram/100 ml. No change in maternal T4 concentration was observed. The mean cord serum T4 concentration in premature newborns delivered more than 3 days following T4 intra-amniotic injection, however, was not significantly different from that of the controls. These data suggest that T4 (250 microgram) injected intraamniotically is absorbed by the premature human foetus. Furthermore, the hyperthyroxinaemia is only transient, and does not prevent the post-natal T4 surge.

Absorption↗
PubMed1979

Angiotensin II and K challenge following prolonged ACTH administration to normal subjects.

Twelve healthy male volunteers on a normal Na and K intake and ambulatory received ACTH (40 IU, im) twice daily for 5 days followed by 2 days of angiotensin II (5--13 ng/kg body weight/min for 60 min) or oral K citrate (30 mEq./h x 3). A discordance in the aldosterone-stimulating and pressor responses of angiotensin II was unmasked with only the latter response being positive following ACTH-induced refractoriness. K loading was a much more potent natriuretic stimulus than angiotensin II treatment. In contrast to angiotensin II, K could selectively enhance aldosterone secretion by overcoming the inhibition in secretion of the mineralocorticoid induced by prolonged ACTH exposure.

Administration, Oral↗
PubMed1979

Unoccupied binding sites for oestradiol in nuclei from human breast carcinomatous tissue.

The binding of oestradiol to a nuclear fraction extracted from human breast carcinomatous tissue was demonstrated. The material, which was extracted with KCl, sedimented at 3--4S and bound oestradiol with high affinity (dissociation constant approximately 2 X 10(-10) mol/l). Oestriol, diethylstilboestrol and 5 alpha-dihydrotestosterone (100-fold excesses) competed with [3H]oestradiol for the binding sites (binding inhibited by 89 +/- 8 (S.D.), 92 +/- 6 and 57 +/- 8% respectively), whereas progesterone and cortisol (100-fold excesses) did not (binding suppressed by 5 +/- 5 and 2 +/- 3% respectively). Similar competition patterns were found for cytoplasmic material which bound oestradiol. The binding occurred at 4 degrees C and was therefore considered to be a measure of the amount of binding material unoccupied by endogenous oestrogen, Unoccupied binding sites for oestradiol in the nucleus and cytoplasm were measured in 35 samples of breast carcinomatous tissue using sucrose gradient centrifugation. In 17 out of 35 tumorus, unoccupied nuclear and cytoplasmic 8S and 4S binding sites could be detected. Three out of 35 tumours contained unoccupied nuclear binding sites and 4S cytoplasmic binding sites. Nuclear binding sites only were found in two out of 35 tumours. Unoccupied nuclear binding sites were not detected in 13 out of 35 tumours and ten of these tumours also did not contain unoccupied cytoplasmic binding sites.

Adult↗
PubMed1978

Hormonal and clinical responses in amenorrhetic patients treated with gonadotropins and a nasal form of synthetic gonadotropin-releasing hormone.

Synthetic gonadotropin-releasing hormone (GnRH) in the form of nasal drops was self-administered by five amenorrheic patients in an attempt to assess its therapeutic value in anovulatory infertility. After follicular maturation had been induced with human menopausal gonadotropins (HMG), a total daily dose of 7.5 mg of GnRH in the form of nasal drops was self-administered at 2-hour intervals for 6 hours on 3 consecutive days. In four patients, plasma luteinizing hormone (LH) levels were significantly elevated over a period of at least 8 hours. In three of these patients, in addition, there was a definite upward shift in the basal body temperature (BBT) curve, and uterine bleeding occurred 6 to 9 days after the first dose of GnRH. In the fourth patient, ovulation was induced as indicated by a biphasic BBT curve, a plasma progesterone level of 13 ng/ml, and a luteal phase of 15 days. In the remaining patient, there was a borderline LH response and no clinical response. It is concluded that GnRH, in the form of nasal drops, is effective in eliciting and maintaining elevated plasma LH levels in patients in whom follicular maturation has been induced with HMG. By obtaining ovulatory LH levels, such a regimen can lead to ovulation. In addition, intranasal self-administration of GnRH is convenient and may provide an alternative route of administration for long-term therapy with this hormone.

Administration, Intranasal↗