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Biomedical subjects

F Tejada

Publications and source records attributed to F Tejada.

At least 19 recordsLinked to original sources

Potassium regulates plasma testosterone and renal ornithine decarboxylase in mice.

Potassium deficiency produced different effects in the kidney of male or female mice. While in female, potassium deficiency caused a marked renal hypertrophy with no significant changes in testosterone-regulated enzymes, such as ornithine decarboxylase and beta-glucuronidase, in the male the same treatment provoked a marked fall of these enzymes owing to a dramatic decrease in plasma testosterone. Potassium replenishment restored plasma testosterone and renal enzymatic activities. These results show for the first time, that potassium modulates circulating testosterone and suggest that this cation could exert an important regulatory role in controlling androgen actions.

Animals

Postoperative whole lung irradiation with or without adriamycin in osteogenic sarcoma.

Thirty-six patients with histologically proven osteogenic sarcoma of the extremities, treated between September 1975 and April 1978, are the subject of this report. The primary tumor was treated with radical surgery. Patients received 2000 cGy whole lung irradiation postoperatively in an attempt to control micrometastases to the lung. Twenty-nine of the patients were given Adriamycin (60 mg/m2 IV every 6 weeks for a total dose of 550 mg/m2) in addition to the irradiation. The median, disease-free interval was 118 days for the seven patients treated with lung irradiation only. The median overall survival for these patients is 241 days, with one patient alive with disease. All patients developed lung metastasis. For the 29 patients treated with postoperative lung irradiation and Adriamycin, the median disease-free interval was 372 days, and the median overall survival is 843 days. Nineteen of the patients recurred (65.5%). The differences are statistically significant (p less than or equal to 0.003, median disease-free survival and p less than or equal to 0.03, median survival). This study supports the role of whole lung irradiation plus Adriamycin, in the control of micrometastases in osteogenic sarcoma of the extremities and suggests that additional clinical trials are warranted.

Adolescent

Local control of osteogenic sarcoma by radiation and chemotherapy.

Sixteen patients with osteogenic sarcoma of limbs were treated with high dose methotrexate followed by leucovorin rescue, adriamycin and radiotherapy to the primary tumor. A post-treatment surgical biopsy was performed in 15 of the 16 patients. In 12 of 15 patients (80%), the follow-up biopsy was negative for active tumor. Complications of treatment were myelosuppression (16 cases), moist desquamation (13 cases), soft tissue necrosis (2 cases) local infection (2 cases), fibrosis (9 cases) and bone fracture (4 cases). The mean survival time in this group of patients was 712 days.

Adolescent

Combination chemotherapy of the epipodophyllotoxin derivatives, teniposide and etoposide. A pharmacodynamic rationale?

Previous studies in vitro on the influence of extracellular protein binding of Teniposide (VM26) and Etoposide (VP16-213) on subsequent cellular uptake by experimental murine tumor cells [Cancer Res 38:2549 (1978); Drug Metab Rev 8:119 (1978)] suggested that a timed-sequential combination of VM26 and VP16-213 may increase the bioavailability of VP16-213. This was studied clinically in six cancer patients with ascites (five ovarian, one rectal) whereby VM26 (20 mg/m2) was given i.p. 2 h prior to VP16-213 (100 mg/m2; i.p.) In some patients, this regimen was administered i.v. The i.v. regimen was found to be more toxic (myelosuppression, nausea, vomiting) than i.p. regimen at same doses of drugs. Several patients remained stable to disease during 1-2 courses of therapy (3 weeks per course), one patient had partial remission, and has been stable in her disease for more than 4 months. In two patients, plasma and ascites fluid was analyzed for VP16-213 and VM26 by a new reverse-phase high performance liquid chromatography method. Both VM26 and VP16-213 could be eluted isocratically (28% v/v acetonitrile in water) from a c18 column with retention times of 6.6 and 13.3 min, respectively. Subsequent pharmacokinetic analysis of one patient suggests that protein binding displacement of VP16-213 in plasma and perhaps ascites fluid increased the pharmacokinetic volume of distribution (28 l) and reduced the elimination half-life (12 h). The data suggests that VP16-213 is distributed more widely in the body and is represented by a single compartment pharmacokinetic model. Analysis of VM26 in ascites and plasma suggests that the so-called "deep pharmacokinetic compartment" represents ascites equivalent space and that the plasma concentration represents VM26 as free and protein-bound drug in kinetic distinguishable compartments. Determinants of drug action are potentially composed of a multiplicity of physiological, biochemical, and other factors. The potential for manipulating the pharmacodynamic properties of drugs to achieve greater therapeutic potential needs further study.

Adult

Penile angiosarcoma presenting in bladder.

A case of angiosarcoma of the right corpus cavernosum with direct extension to the bladder, prostate, and seminal vesicles and metastasis to brain, liver, and cheek is presented, and the literature is reviewed.

Brain Neoplasms

Vincristine effect on methotrexate cerebrospinal fluid concentration.

A 67-year-old man with malignant lymphoma, nodular, poorly differentiated lymphocytic type, developed meningeal lymphomatosis. Repeated high-dose methotrexate-citrovorum factor treatment (1 g/m2 in 24 hours) rendered the patient free of disease. The administration of vincristine at 23 hours consistently increased the concentration of methotrexate in the cerebrospinal fluid 2.5-fold above baseline values.

Aged

Adjuvant whole-lung radiation with or without adriamycin treatment in osteogenic sarcoma.

Eighteen consecutive patients with osteogenic sarcoma were treated after initial surgery with 2000 rads of whole-lung radiation for 21--28 days. Eleven of these patients went on to receive adriamycin (20 mg/m2 X 3 days every 6 weeks). Three of seven evaluable patients are free of disease in the radiation group (median time to recurrence, 130 days) while six of ten evaluable patients are free of disease in the radiation + adriamycin group (median time to recurrence, 310+ days). These results are similar to published experience with whole-lung radiation and adriamycin alone.

Adolescent

Placental proteins and their subunits as tumor markers in prostatic carcinoma.

Sixteen patients with Stage D adenocarcinoma of the prostate were prospectively evaluated for the presence of human placental lactogen (hPL), placental alkaline phosphatase (PAP), and human chorionic gonadotropin (hCG). Ectopic production of hCG was found in one of the 16 cases and is described in detail. Serial serum hCG levels in that patient mirrored his course more reliably than concomitant acid phosphatase levels. Serum estradiol, testosterone, the hCG-alpha subunit, hPL and PAP were not elevated. There was a minimal elevation of serum FSH. There were no elevations of the other placental proteins in ten evaluable cases. A retrospective evaluation of serum bank specimens from 47 patients with prostatic carcinoma revealed no elevation of the placental proteins hPL, hCG-beta, and hCG-alpha. To our knowledge this report documents the first case of a chorionic gonadotropin-producing prostatic carcinoma appearing the literature.

Adenocarcinoma

Cardiac metastases in lung cancer.

Cardiac metastases from bronchogenic carcinoma are not commonly diagnosed prior to death. This study isolates factors associated wtih the development of cardiac involvement. Four hundred eighteen consecutive patients with lung cancer who had autopsies were studied. Twenty-five percent of these patients had cardiac involvement. Factors associated with cardiac metastases were (1) histologic cell type of the tumor, (2) aggressive therapy, (3) extent of disease, and (4) tumor differentiation. The presence of cardiac metatases was not related to the length of survival. Clinical signs of cardiac involvement included an enlarging heart on the chest x-ray film, development of congestive heart failure, or electrocardiographic changes. Suspicion of cardiac metastases in high-risk individuals, prompt diagnostic evaluation, and rapid institution of therapy may improve the outlook for many patients, since reaccumulation of fluid was generally slow.

Adenocarcinoma

Phase I clinical trial of isophosphamide (NSC-109724).

An initial clinical phase I trial of isophosphamide has been carried out at dose levels of 200-10,000 mg/m2 of body surface area using a single-dose, every-3-week schedule. Significant toxicity was not seen at isophosphamide dose levels less than 2900 mg/m2. At higher doses, nausea and vomiting was nearly universal. Hematologic toxicity manifested by leukopenia occurred in 12 of 20 patients treated with doses of 3800-7000 mg/m2. Thrombocytopenia to 100,000 platelets/mm3 was not seen in any patient. Urinary bladder toxicity manifested by hemorrhagic cystitis was seen in 15 of 23 patients treated with doses of 3800-10,000 mg/m2. Hemorrhagic cystitis could be completely prevented by bladder irrigation with N-acetyl-L-cysteine (1% solution, 2000 ml/day). With careful attention to hydration, renal toxicity was largely prevented with blood urea nitrogen elevations to 30 mg/dl in only two of 14 patients receiving isophosphamide doses of 5000-7000 mg/m2. Another side effect was central nervous system toxicity in seven of 17 patients at doses of 5000-10,000 mg/m2. For phase II trials a dose of 5000 mg/m2 is recommended, with careful attention to the state of hydration in the patient and with the knowledge that bladder irrigation may be necessary for the prevention and/or amelioration of bladder toxicity.

Adenocarcinoma