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Biomedical subjects

D H Johnson

Publications and source records attributed to D H Johnson.

At least 307 records · Page 17Linked to original sources
PubMed1985

Effect of a luteinizing hormone releasing hormone agonist given during combination chemotherapy on posttherapy fertility in male patients with lymphoma: preliminary observations.

Six men undergoing potentially curative chemotherapy for advanced lymphomas received daily injections (50 micrograms) of an analogue of luteinizing hormone releasing hormone (LH-RHa) in an attempt to protect posttreatment gonadal function. The median duration of combined LH-RHa-chemotherapy administration was 25 weeks (range, 14 to 31 weeks). During the simultaneous administration of LH-RHa and chemotherapy, plasma testosterone levels decreased to subnormal levels, while both follicle-stimulating hormone (FSH) and luteinizing hormone levels declined to the lower limit of normal. All subjects became oligospermic or azoospermic within eight weeks of starting treatment. Following discontinuation of chemotherapy and LH-RHa, both plasma testosterone and LH promptly increased and stabilized within the normal range. FSH progressively increased to a level well above the normal range. Only one patient has recovered evidence of active spermatogenesis at 84 weeks postcessation of chemotherapy. No untoward side effects due to LH-RHa were experienced. Although LH-RHa can be administered safely during combination chemotherapy, no improvement in posttreatment fertility has yet been demonstrated.

Adolescent↗
PubMed1984

Testicular function following combination chemotherapy with cis-platin, vinblastine, and bleomycin.

Recovery of the pituitary-gonadal axis following treatment with vinblastine, bleomycin, cis-platin +/- doxorubicin (VBP +/- A) is assessed retrospectively in 18 men with germinal neoplasms. One patient also received VP-16-213. In the first year after completing treatment all men demonstrated elevated follicle stimulating hormone (FSH) and luteinizing hormone (LH) values with concomitant azoospermia. Of the 11 men evaluated at least 24 months from completion of therapy, seven (64%) had recovery of both FSH and LH to normal or near normal levels. Spermatogenesis was present in five of six (83%) men providing semen samples and who were at least 2 years from stopping VBP. Five of seven (71%) men who were within 24 months of therapy were azoospermic. Regardless of the time of evaluation, most men (94%) had normal serum testosterone. Patients receiving maintenance vinblastine had more prolonged elevation of serum gonadotropins. We conclude that some men have evidence of recovery of fertility beginning two years after VBP +/- A. In addition to germinal epithelium destruction, transient Leydig cell dysfunction occurs but is not accompanied by clinical findings of hypogonadism.

Adolescent↗
PubMed1984

A one-year multicenter clinical trial of pilocarpine gel.

In a one-year clinical trial of pilocarpine gel, a form designed for once-a-day administration, in 83 patients with glaucoma, average intraocular pressures during gel therapy were equal to or slightly lower than previous values during pilocarpine eyedrop therapy (morning values, 18.7 mm Hg vs 19.7 mm Hg; afternoon values, 20.9 mm Hg vs 20.2 mm Hg). Monitoring of diurnal intraocular pressure showed that 33 of 77 patients (43%) using the gel and 25 of 77 (33%) using eyedrops had afternoon values more than 2 mm Hg higher than their morning values. This difference was not statistically significant. Fifteen of 76 patients (20%) who used the gel for more than eight weeks developed a diffuse superficial corneal haze with gel treatment. The haze persisted 12 months after the gel was discontinued. Although the haze produced no symptoms, its long-term consequences are unknown.

Adult↗
PubMed1984

Tetralogy of Fallot and coarctation of the aorta: successful repair in an infant.

A 4 1/2-month-old infant was referred to our center with the rare combination of tetralogy of Fallot and coarctation of the aorta. Despite the presence of severe right ventricular outflow obstruction, the infant was virtually acyanotic because of the systemic afterload associated with the coarctation. She had marked systemic hypertension. The embryological and therapeutic implications of this child's defects are discussed.

Aortic Coarctation↗
PubMed1984

The feasibility of adjuvant surgery in limited-stage small cell carcinoma: a prospective evaluation.

Forty patients with limited-stage small cell carcinoma of the lung were prospectively evaluated for adjuvant surgery after intensive chemotherapy to determine resectability. All patients giving informed consent and having a Karnofsky performance status greater than or equal to 50% were included in the study, which ran from May, 1980, to September, 1982. Ages ranged from 40 to 70 years (median, 59 years). One patient was lost to follow-up. Thirty-nine patients were evaluated for operation 9 to 15 weeks after diagnosis and after having received two to four cycles of chemotherapy intravenously every 3 weeks (cyclophosphamide, 1,000 mg/m2; doxorubicin, 50 mg/m2; vincristine, 1 mg/m2; VP-16, 300 mg/m2). Two patients had clinical Stage I tumors; 12 patients, Stage II; and 25 patients, Stage III. At the time of reevaluation there were 13 (33%) complete responders, 21 (54%) partial responders, and 5 (13%) with stable disease. Eleven (28%) of the 39 patients underwent thoracotomy using standard resection criteria for non-small cell carcinoma. Eight of these 11 had resectable lesions (2, Stage I; 3, Stage II; 3, Stage III); five pneumonectomies and three lobectomies were performed. Tumor was present in six of eight specimens. Twenty-eight patients were not candidates for operation for various reasons: poor pulmonary function, 5; unresectable tumors, 10; refusal, 6; very poor medical condition, 6; and primary site not identified, 1. Median survival for complete responders was 17 months and for partial responders, 11 months. We have prospectively identified suitable candidates for adjuvant surgery among the total group (denominator population) of patients with limited-stage small cell carcinoma.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1984

Computed tomography in medial maxilla-orbital fractures.

The frontal process of the maxilla together with the anterior wall of the antrum constitute a major support of the midface. If this is fractured and goes unrecognized, serious facial deformities result. Fractures through this process occurred in 13 of 50 patients who received computed tomographic examination for facial trauma. The fracture had been missed on plain film examination in all but three of the 13 patients. The frontal process is usually displaced directly posteriorly in the more complex midface fractures. It may rotate about its long axis when associated with trimalar fractures and in some of the isolated injuries of the medial maxilla. Computed tomography is the ideal technique for demonstrating these fractures because of ease of examination, optimal anatomical display for demonstrating rotational and posterior displacements, and superior contrast in the severely traumatized facial skeleton.

Facial Injuries↗
PubMed1984

Jugular foramen syndrome as a complication of metastatic cancer of the prostate.

The jugular foramen syndrome results from paralysis of various combinations of any of the last four cranial nerves. While trauma, vascular disease, and infection may be etiologic, most cases result from malignancies, usually metastatic. We have described a case of metastatic adenocarcinoma of the prostate resulting in the Collet-Sicard variant of this syndrome.

Adenocarcinoma↗
PubMed1984

High-dose VP-16-213 monotherapy for refractory germinal malignancies: a phase II study.

VP-16-213 at standard dose is one of the more active agents for the treatment of germ cell tumors. In previous phase I studies, VP-16-213 has been investigated in suprastandard dose when hematopoietic reconstitution was assured by autologous bone marrow transplantation (ABMT). This phase II study was performed to explore the possibility that an augmented dose of VP-16-213 may be more active than standard dose against germ cell tumors. Eleven patients with progressive refractory germ cell tumors were treated with high-dose VP-16-213: 2,400 mg/m2 with ABMT every three to four weeks followed by 1,200 mg/m2 without ABMT. Seven patients had received VP-16-213 at standard dose prior to high-dose VP-16-213. Toxicity to high-dose VP-16-213 included severe myelosuppression, nausea, vomiting, alopecia, mucositis, and hepatitis. Of 10 evaluable patients, two complete responses and four partial responses, all of short duration, were obtained. However, some patients unresponsive to standard-dose VP-16-213 exhibited responses to the augmented-dose VP-16-213. Therefore, although more myelosuppressive, VP-16-213 may have increased activity against germ cell tumors when administered at augmented dose. High-dose VP-16-213 may be considered in designing new approaches for initial management of patients with germ cell tumors not expected to be cured with standard chemotherapy.

Adolescent↗
PubMed1984

Potential utility of serum neuron-specific enolase levels in small cell carcinoma of the lung.

To assess the value of neuron-specific enolase (NSE) as a possible biomarker of small cell lung cancer, serum levels were determined by radioimmunoassay in 93 newly diagnosed untreated patients and were compared to the NSE levels of 20 healthy adult controls [9.6 +/- 0.7 (S.E.) ng/ml]. Serum NSE was elevated (greater than 20 ng/ml) in 73% of all patients including 23 of 39 (59%) with limited-stage disease and 45 of 54 (83%) with extensive-stage disease. The mean serum NSE was significantly higher in extensive-stage disease (94.5 +/- 13.8 ng/ml) compared to the mean value for limited-stage disease (33.7 +/- 4.7 ng/ml) (p less than 0.001). NSE was elevated in all patients with three or more sites of metastatic disease. Serial NSE determinations were obtained on 57 small cell lung cancer patients. NSE levels fell in 40 of 50 (80%) of patients responding to treatment, increased in 5 of 7 (71%) of patients with progressive disease, and increased in 30 of 35 (86%) of patients who relapsed. A persistent rise in serum NSE occurred as many as 12 weeks before the clinical recognition of relapse in 15 of 23 (65%) of patients for whom adequate serial NSE data were available. These findings indicate that serum NSE may be a useful marker for staging, monitoring treatment, and predicting relapse in patients with small cell lung cancer.

Carcinoma, Small Cell↗
PubMed1984

CT of maxillofacial trauma.

Failure to recognize facial fractures is an important cause for later cosmetic and functional complications. Using limited preliminary plain film study in the Water's projection can usually predict the need for more sophisticated imaging and can serve as a basis for proper planning of CT examination, the procedure of choice when more sophisticated imaging is indicated. This article describes how and when to use CT, with an emphasis on which projection(s) to use for which injury.

Facial Bones↗
PubMed1983

Purine-resistant Drosophila melanogaster result from mutations in the adenine phosphoribosyltransferase structural gene.

Mutants of Drosophila melanogaster selected for resistance to purine killing are deficient in adenine phosphoribosyltransferase (APRT; E.C. 2.4.2.7) activity. Genetic mapping and complementation analysis demonstrate that purine resistance, deficiency of APRT activity, and differences in the isoelectric point of APRT result from alterations at a single locus, Aprt (map position, 3:3.03). The level of APRT activity shows gene dose dependence in Aprt heterozygotes and in flies that are haploid for different Aprt alleles. Drosophila APRT is a dimer composed of apparently identical 23,000-dalton subunits. These results suggest that Aprt contains the structural gene for APRT.

Adenine Phosphoribosyltransferase↗
PubMed1983

The transmission of signals by auditory-nerve fiber discharge patterns.

Recent developments in the theory of point processes are used to analyze the accuracy by which signals are conveyed by the discharges of single auditory-nerve fibers. It is shown that the only spike trains which can convey a signal without distortion are those well-described by a Poisson process model. Theoretical predictions are made of the distortion present in the transmission of signals by auditory-nerve fiber discharge patterns. Absolute refractory effects are shown to result in more distortion than relative refractory ones. Procedures are developed to compensate for these distortions. The procedures designed to compensate for absolute refractory effects operate on the PST histogram. Computer simulations are used to confirm the theoretical predictions and to assess the accuracy of the compensation techniques.

Animals↗
PubMed1983

Role of Franzen needle aspiration biopsy in carcinoma of the prostate.

A retrospective study is reported of all Franzen fine-needle aspiration cytology undertaken at Southmead Hospital between January 1978 and December 1981. A total of 1043 aspirates were examined from 753 patients. The diagnosis of carcinoma of the prostate was missed in 2 patients. Twenty-one patients with cytologically-proven carcinoma in histologically-benign prostates were detected, and the role of the Franzen needle in the diagnosis of early prostatic cancer is discussed. Of the 218 patients proceeding to prostatectomy, there were 91 patients with carcinoma and in 65 (72%) the cytological and histological grading was identical. A significant disparity occurred in 8 cases and the reasons are discussed.

Biopsy, Needle↗
PubMed1983

Limited value of CT brain scans in the staging of small cell lung cancer.

Computed tomography of the brain was performed as part of the initial staging evaluation of 84 patients with small cell lung cancer. Brain scans indicative of metastatic disease were obtained in 12 (14%) patients, two of whom had no neurologic signs or symptoms. One of these had no other extrathoracic disease. Brain scans without evidence of metastatic disease were obtained in 72 patients, 58 (80.5%) of whom had no signs or symptoms suggestive of metastatic intracranial disease. In the 14 patients with neurologic symptoms but negative computed tomographic scans, other explanations than brain metastases were found. It was concluded that head scanning is a sensitive and accurate method of detecting central nervous system metastases in patients with small cell lung cancer. However, head computed tomography should not be included as part of the initial staging evaluation of the neurologically asymptomatic patients. In only one of 60 such patients did the brain scan change the initial clinical staging, which included chest films, liver and bone scans, and bone marrow biopsy.

Adult↗