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Biomedical subjects

J Brodkey

Publications and source records attributed to J Brodkey.

11 recordsLinked to original sources
PubMed1984

Conditioning of the diaphragm with phrenic nerve stimulation after prolonged disuse.

We studied the effect of electrical stimulation of the phrenic nerve on the force frequency relationship of the disused diaphragm. A high quadriplegic who had been totally ventilator dependent for 6 months following a C2 fracture received bilateral phrenic nerve stimulators. During a 6-wk period of conditioning by electrical stimulation, the force of diaphragm contraction was assessed by measurement of transdiaphragmatic pressures during stimulation of each nerve over a range of frequencies. Tidal volume as well as rib cage and abdominal motion were studied. There was an upward shift of the force frequency relationship of the diaphragm over the 4-month period of phrenic nerve pacing using repetitive stimulus trains of 14 to 28 Hz. This improvement appeared to plateau at about 11 wk. The increase in contractility was accompanied by a progressive diminution in the stimulus frequency at which fusion of the contraction occurred. The disused diaphragm, like other skeletal muscle, may be conditioned with electrical stimulation.

Aminophylline↗
PubMed1979

Antihormone treatment of stage IV breast cancer.

The antiestrogen Tamoxifen (T), given orally to 113 patients with stage IV breast cancer, induced objective remission in 50%. Duration of remission in the first 39 patients, with minimum 27 months follow up, is 18 + months; these results are equal to those of surgical hypophysectomy. T prolonged survival in responders. Older age, previous response to endocrine therapy and positive estrogen receptors predicted response to T. T was effective in hypophysectomized patients in whom serum growth hormone and prolactin were undetectable, but serum ostrogens were present in low amount, suggesting a direct stimulatory effect of estrogens at the tumor level. Hypophysectomy induced further palliation after treatment with T, indicating that pituitary hormones may also play a role in the growth of some human breast cancers. Side effects from T were minimal. T is the initial treatment of choice for postmenopausal women with hormone responsive stage IV breast cancer.

Breast Neoplasms↗
PubMed1979

Transsphenoidal hypophysectomy in breast cancer: evidence for an individual role of pituitary and gonadal hormones in supporting tumor growth.

Transsphenoidal hypophysectomy was performed in 212 consecutive patients with metastatic breast cancer: 11 died within 30 days, two of surgical complications and nine of advanced metastatic disease. Two patients were unevaluable because of inadequate follow-up in one and simultaneous radiation treatment in the other. Of 199 evaluable patients 42% had an objective remission. Duration of remission averaged 18+ months with 10 out of 84 patients still in remission. Presence of estrogen receptors in the tumor significantly predicted response to hypophysectomy. Of 156 patients in whom completeness of hypophysectomy was assessed, 128 were thought to have a complete removal as shown by the fact that their growth hormone and prolactin were undetectable after stimulation with arginine or chlorpromazine, respectively. Of 26 patients in whom TRH test was performed, TSH and prolactin were undetectable in 20. Of 23 patients where autopsy was performed only six had microscopic pituitary tissue remaining. Hypophysectomy induced remission in eight of 15 patients who had previously responded and then relapsed to the antiestrogen Tamoxifen and in four of 17 who had failed. Conversely, antiestrogen therapy induced remission in six of 26 patients who had previously responded to hypophysectomy and in whom serum estrogens were present in small amount. These data indicate that both gonadal and pituitary hormones play a role in the growth of some human breast cancers.

Adult↗
PubMed1978

Role of pituitary hormones in the growth of human breast cancer.

Hypophysectomy was performed in 28 women with Stage IV breast cancer who were treated initially with antiestrogens. Six of 13 patients who responded to tamoxifen and 2 of 12 who failed to benefit from tamoxifen obtained remissions from hypophysectomy. The remissions average 11+ months. Three of 8 patients treated initially with antiestrogens have responded to androgen therapy. The results suggest that hormones other than estrogen, which appears to play a major role, may be involved in stimulating the growth of some human breast cancers. Prolactin receptors were detectable in 51% of human breast cancers and were detected in both estrogen receptor-positive and -negative tumors. Preliminary clinical correlations suggest that prolactin receptors will not be useful in predicting response to antiestrogen therapy.

Breast Neoplasms↗
PubMed1977

Treatment of breast cancer with antiestrogen: approach to medical hypophysectomy?

Tamoxifen (ICI 46474), an antiestrogen, was given to 89 selected patients with stage IV breast cancer at a dose of 20 mg orally every 12 hours. Forty-seven percent of the patients had objective tumor regression averaging 11+ months with 25 of 42 women still in remission. In the first 39 patients where the minimum follow-up period is 16 months the average duration of remission is more than 15 months with 8 of 19 patients still in remission. These results are approaching those of surgical hypophysectomy, where, in our experience the average remission lasts about 18 months. Thus, Tamoxifen is a highly effective antitumor agent and is probably the initial treatment of choice for women with hormone responsive breast cancer. Antiestrogen induced objective remissions in 5 of 19 patients who had previously responded to surgical hypophysectomy, and 5 additional patients showed no progression of disease lasting 15+ months. Estradiol and estrone were detectable in the serum of these patients whereas, prolactin and growth hormone were not detectable. Thus, antiestrogen can induce remissions in some patients in the absence of the pituitary gland, and this constitutes additional palliation and provides evidence that estrogens can directly stimulate tumor growth. Four of 7 patients who obtained remissions from Tamoxifen obtained further improvement from hypophysectomy, and 1 of 8 patients who failed to benefit from antiestrogen improved after hypophysectomy. These results suggest that prolactin and growth hormone may also play a role in stimulating tumor growth in some patients.

Animals↗