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Biomedical subjects

J C Prior

Publications and source records attributed to J C Prior.

67 records · Page 4Linked to original sources

Human myometrium: a new potential source of prolactin.

Human myometrium is shown for the first time to produce prolactin in vitro. This prolactin is similar to pituitary prolactin by criteria of immunologic identity, gel chromatography and bioassay. The de novo synthesis of myometrical prolactin is supported by no detectable prolactin in initial tissue homogenate, nondetectable prolactin production during the first 24 hours of culture, cycloheximide inhibition of prolactin production with recovery of production in control medium, and tritiated leucine incorporation into prolactin. Although human myometrium is capable of producing prolactin without the addition of exogenous hormones, the addition of estrogen and progesterone, respectively, enhances and suppresses prolactin production in contrast to decidualized human endometrium where opposite effects on prolactin production are found.

Culture Techniques↗

Dialysis encephalopathy and osteomalacic bone disease: a case-controlled study.

Nine patients on long-term hemodialysis with dialysis encephalopathy were studied, with sex matched control subjects for eight of the patients. Each patient with dialysis encephalopathy and control subject were contemporaries in a similar dialysis environment. Rib and other fractures were found in excess in the patients with dialysis encephalopathy (p less than 0.005 and p less than 0.01). These patients had less radiographic hyperparathyroid bone disease, and no more osteopenia as measured by metacarpal thickness than did their control counterparts. Severe osteomalacia was documented by bone biopsy in four of te patients. In a retrospective review of clinical, biochemical and pharmacologic differences, the patients with dialysis encephalopathy were significantly older at the start of dialysis (45.6 years versus 38.6 years, p less than 0.02) and had higher mean concentrations of blood urea nitrogen (BUN) and lower serum hemoglobin in the first year of dialysis than the control subjects. Blood pressure weight, creatinine, calcium, phosphate, alkaline phosphatase and a number of transfusions did not differ significantly. There was no difference in prescribed vitamin D and elemental aluminum in phosphate binders. This study demonstrates that patients with dialysis encephalopathy had more rib fractures without more parathyroid or osteopenic bone disease than did the control subjects and suggests that the etiology of dialysis encephalopathy and osteomalacia is multifactorial.

Adult↗

Endocrine "conditioning" with endurance training a preliminary review.

The human individual responds as an entire organism to the effect of endurance training. Exercise physiologists have long documented cardiovascular, musculo-skeletal and metabolic effects of conditioning. Only recently are we beginning to understand that there are hormonal and hypothalamic changes which occur with conditioning. These hormonal changes probably serve similar adaptive functions as do the other conditioning responses. Careful controlled studies need to be performed of individuals prior to, early in conditioning, and following extended periods of conditioning looking at hypothalamic function, body morphometric characteristics, psychiatric and psychological testing and menstrual cycle data in order to better understand hormonal conditioning. When hormone changes occurring with endurance training are approached in this light, the complex inter-related alterations will begin to form a pattern. Further studies are needed to document the dynamic and reversible nature of these hormonal adaptations.

Amenorrhea↗

Menstrual cycle changes with marathon training: anovulation and short luteal phase.

Fourteen normal women (self-selected from 180 women enrolled) in a marathon training clinic kept basal body temperature (BBT), mileage, and weight records for 48 cycles before the marathon. Entry criteria were: Age 20-45, gynecologic age greater than 5 years, no hormone use, or weight change in 3 months. The women were 35.2 +/- 5.6 years in age, 22.6 +/- 5.1 years gynecologic age, runners of 4.1 +/- 2.5 years with premenstrual symptoms, previous pregnancy 4/14, no infertility and 2/14 remote amenorrhea. BBT records were obtained and analyzed by Vollman's criteria (1977). There was no weight loss. 32/48 cycles were biphasic but only 16 were normal in the length of the premenstrual phase (PreM = luteal, nl 10 - 16 d) with a mean of 11.1 +/- 1.2 days. The other 16 biphasic cycles had short PreM phase of 6.4 +/- 1.8 days. Monophasic (M = anovulatory) cycles occurred in 16/48 records. Cycles which were abnormal (Short PreM and M) differed only in that usual run length was longer (9.6 - 9.9 miles) than in normal cycles (7.9 +/- 2.4 miles). Marathon training may be associated with normal length but M and short PreM type cycles.

Adult↗

Hemodialysis patients with a unique mineralizing defect unresponsive to 1,25-dihydroxycholecalciferol. Dialysis osteomalacic syndrome.

5 patients are described who developed severe osteomalacia with spontaneous fractures after 2-4 years on dialysis. Phosphate control, vitamin D2 therapy and parathyroidectomy were ineffective. These individuals showed a hypercalcemic tendency but little histologic or radiographic evidence of osteitis fibrosa. After parathyroidectomy, the hypercalcemic tendency remained and bone biopsy revealed gross osteomalacia. A 6- to 12-month therapeutic trial with 1,25-dihydroxycholecalciferol (1,25[OH]2D3) in 3 did not arrest skeletal deterioration. 4 subsequently developed dialysis encephalopathy. These patients appear to have a unique mineralizing defect unresponsive to 1,25(OH)2D3. This "dialysis osteomalacic syndrome" may result from toxic substances associated with uremia or the hemodialysis regimen.

Adult↗

Experience with 1,25-dihydroxycholecalciferol therapy in undergoing hemodialysis patients with progressive vitamin D2-treated osteodystrophy.

Six long-term hemodialysis patients with progressive skeletal deterioration during long-term pharmacologic vitamin D2 therapy were treated for six to 12 months with oral 1,25-dihydroxycholecalciferol (1,25-(OH)2D3) to determine its therapeutic effectiveness in vitamin D2-unresponsive osteodystrophy. On bone biopsy, three of the patients had severe osteomalacia and three showed predominant osteitis fibrosa. Previous therapies, including phosphate binders and dialysis schedules, were maintained. The three patients with osteomalacia and the two with osteitis fibrosa showed clinical deterioration. There was no significant change in serum calcium, phosphate, alkaline phosphatase, bone densitometry, immunoreactive parathyroid hormone levels or bone histology. Roentgenograms showed multiple new fractures of ribs and femoral necks in the patients with osteomalacia and increased bone resorption in two of three patients with osteitis fibrosa. 1,25-(OH)2D3 dosage had to be decreased in all patients because of hypercalcemia with a mean tolerated dose of 0.22 microgram/day. In these patients, 1,25-(OH)2D3 was not effective therapy for progressive osteodystrophy unresponsive to pharmacologic vitamin D2.

Adult↗

Gonadal steroids in athletic women contraception, complications and performance.

Gonadal steroids are altered by the reproductive system's adaptation to conditioning exercise. Contraceptive options for the athletic woman include all measures appropriate for the sedentary woman. Barrier methods (always with spermicidal jelly) are the preferred choice. The cardiovascular risks, decreased aerobic performance, and shorter time to muscular exhaustion related to oral contraceptives make this a less desirable option. Potential complications from the steroid changes of intense exercise include: low oestrogen and progesterone with risk of loss of trabecular bone and early osteoporosis, and absent progesterone with low normal oestrogen levels associated with risk of endometrial or breast cancer. Therapeutic options for the amenorrhoeic or young athlete include supplemental oral calcium, cyclic oral progesterone, or possibly cyclic physiological oestrogen and progesterone. The anovulatory (usually older) athlete with regular menses needs cyclic progesterone. Medroxyprogesterone 10mg on days 16 to 25 of the cycle or for 10 days monthly can potentially prevent endometrial and breast cancer, give predictable cycles, improve trabecular bone balance and stimulate the return of ovulatory cycles. A practical approach to anovulatory infertility in the athlete includes a 10% reduction in exercise intensity and/or an increase in percentage body fat to 18 to 20%. Cyclic vaginal progesterone (25mg bid) can then treat short luteal phase cycles. With improved understanding of the hormonal adaptations to conditioning exercise, we will be better able to outline contraceptive and therapeutic options in the future.

Contraceptives, Oral↗

Use of tactile techniques for self-monitoring of blood glucose in visually impaired patients with diabetes mellitus.

Twenty-eight patients with type I diabetes mellitus, legally blind as a result of proliferative retinopathy, were recruited into a program designed to teach and evaluate tactile methods for self-monitoring of blood glucose (SMBG). Vision ranged from "blind" to "able to read large print." Techniques with wipe-off strips (Chemstrip bG or BM Test BG, Boehringer-Mannheim, Canada Ltd., Dorval, Quebec, Canada) use the opposite hand as a guide, operation of timing devices by touch, and special methods for labeling and storing strips. Methods with wash-off strips (Dextrostix, Ames Division, Miles Laboratories, Rexdale, Ontario, Canada) employ the fingers as a guide in directing the wash water. The accuracy of tactile methods was documented. Clinical parameters of glucose control improved in patients with adequate data after 6 mo of tactile SMBG. Glycosylated hemoglobin in 17 patients decreased from 11.3 +/- 2.1% to 9.4 +/- 1.5% (P = 0.005). Patients experienced significantly fewer reactions and low blood sugar readings as well as lowering of mean blood glucose values from 158 +/- 56 to 141 +/- 51 (P = 0.025).

Adult↗