Biomedical subjects

M S Weinberger

Publications and source records attributed to M S Weinberger.

9 recordsLinked to original sources

PubMed1997

Clinical study of alar anatomy and surgery of the alar base.

OBJECTIVES: To analyze and quantify specific aspects of alar base anatomy and to identify anatomic configurations that may be correlated with specific surgical manipulations. DESIGN: Analysis in a population of patients presenting for aesthetic nasal surgery. SETTING: Facial plastic surgery practice. PATIENTS: The photographic slides of 120 white patients who presented for consultation were reviewed. INTERVENTIONS: On the base view of photographic slides, observations were made on the width of the alar base, recurvature of the alar base, thickness of the alar lobule, thickness of the alar wall, and flare of the alar wall. On the lateral view, observations were made on the vertical insertion of the ala on the face (cephalic, normal, or caudal), contour of alar rim in profile (gentle S-shape or straight), size of alar lobule (small, normal, or large), and alar-columellar relationship, with special attention to the presence of alar hooding. MAIN OUTCOME MEASURES: A spreadsheet program was used to analyze the incidence of each configuration and any association between various features of the alar base. RESULTS: Anatomic diversity exists that requires a careful individual analysis for each patient. A planned surgical intervention must fit the patient's unique anatomy. Distinctive configurations of recurvature, vertical insertion, and other aspects of the alar base were observed, with special implications for the surgeon's approach. CONCLUSIONS: Anatomic diversity requires a thorough preoperative examination followed by selection of an approach that addresses the specific anatomic findings. The choice of the best alar reduction and sculpture technique ultimately relies on a precise analysis of the anatomic configuration of the patient's alar base.

Adult↗

PubMed1996

The liposhaver in facial plastic surgery. A multi-institutional experience.

OBJECTIVE: To report a multi-institutional clinical experience with the liposhaver in facial plastic surgery. DESIGN: Nonrandomized, nonblinded, multi-institutional evaluation of the liposhaver in a clinical setting in patients presenting for cosmetic facial liposuction. INTERVENTIONS: Cosmetic facial surgery with the liposhaver was performed in 19 patients (21 procedures) who underwent submental lipectomy, facelift with defatting beneath the facelift flap, and/or correction of deep nasolabial folds. Standardized preoperative and postoperative photographs were obtained. Fat obtained from the abdomen of 1 patient was also studied histologically. This fat was excised sharply and was then liposhaved at varying oscillation speeds. OUTCOME MEASURES: Subjective evaluation by the operating surgeons. RESULTS: The liposhaver was used successfully in all cases. The fat was cleanly shaved and the contour results were even, without dimpling or asymmetry. Operative time was comparable to that for conventional liposuction. Preferred cannula sizes and settings were determined. There were no cases of facial nerve injury, no evidence of increased bleeding intraoperatively, and no hematomas in the immediate postoperative period. One patient developed a small hematoma on postoperative day 5 that was effectively treated with needle aspiration and a pressure dressing. Histologic evaluation of liposhaved abdominal fat showed normal fat cells and well-preserved architecture. CONCLUSIONS: The liposhaver offers a precise alterative to conventional liposuction. It may be less traumatic because it requires low suction pressures and does not rely on the potentially bruising, vigorous, back-and-forth motion for fat extraction typical of conventional liposuction.

Adipose Tissue↗

PubMed1996

A phase I/II study of continuous infusion suramin in patients with hormone-refractory prostate cancer: toxicity and response.

INTRODUCTION: Suramin is a synthetic polysulfonated naphthylurea which has been used for the treatment of African trypanosomiasis and onchocerciasis, but since the mid-1980s has received attention as a possible antiretroviral and antineoplastic agent. OBJECTIVE: This clinical trial of suramin was undertaken as a phase I/II study in patients with hormone-refractory prostate cancer, with the hypothesis that the intensity of therapy with suramin could be increased significantly if measures were undertaken to maintain the plasma concentrations of the drug under 300 microg/ml. METHODS: We report the clinical results of this trial, wherein patients were treated at three different targeted plasma suramin concentrations (275, 215 and 175 microg/ml) for varying periods of time (2, 4 or 8 weeks), with delivery of the drug by continuous intravenous infusion. RESULTS: The major toxicity observed in this trial was neurologic, consisting of a motor and sensory peripheral neuropathy that resulted in both paresis and paralysis of the limbs. Nearly all of this severe (CTEP grade III, IV) neurologic toxicity was observed in the patients treated at a plasma suramin concentration of 275 microg/ml for 4 or more weeks. A single patient treated at 215 microg/ml for 8 weeks developed moderate (CTEP grade III) proximal lower extremity weakness, and no patient treated at 175 microg/ml developed this toxicity. The second most common toxicity observed was infection of the central venous catheter. The overall response rate for all of the evaluable patients was 17% (13 of 75 patients). In addition, prostate-specific antigen (PSA)-defined responses were observed in six patients receiving therapy at 175 microg/ml, but these responses were confounded by cessation of therapy with flutamide during suramin treatment. CONCLUSIONS: In summary, although plasma suramin concentrations were maintained below 300 microg/ml, neurologic toxicity nonetheless occurred with high frequency in patients treated at 275 microg/ml for 4 or more weeks. Therapy at 215 and 175 microg/ml was in general well tolerated, but central venous catheter-related infection, as well as the inconvenience and expense of continuous infusional therapy, make this method of drug delivery impractical. Only moderate antitumor activity was observed during this trial, but it is possible that both continuation of flutamide and flutamide withdrawal during suramin therapy confounded the assessment of suramin's activity in hormone-refractory prostate cancer.

Aged↗

PubMed1996

Differential expression of vascular cell adhesion molecule mRNA and protein in nasal mucosa in response to IL-1 or tumor necrosis factor.

IL-1 and tumor necrosis factor (TNF) are cytokines that share many overlapping functions, including induction of expression of the vascular cell adhesion molecule (VCAM) by endothelial cells. However, because most studies of cytokine induction of adhesion molecules have used human umbilical vein endothelial cells (HUVECs) and not microvascular endothelial cells, the functional significance of such observations to sites of allergic inflammation, such as the nasal mucosa, are at present unknown. We have therefore used nasal mucosa to compare the functional response of these microvascular endothelial cells with HUVECs. HUVECs or nasal mucosal explants were stimulated in vitro with varying concentrations of IL-1 or TNF for 0 to 48 hours, and VCAM mRNA and protein expression were determined by means of immunostaining and in situ hybridization. TNF and IL-1 were equivalent in their ability to induce VCAM mRNA and protein expression by HUVECs. In contrast, TNF was significantly more potent than IL-1 in inducing VCAM mRNA and protein expression by nasal mucosal microvascular endothelial cells. The recovery of significant amounts of IL-1 after incubation of recombinant IL-1 with nasal mucosa, as well as the ability of IL-1 to induce intercellular adhesion molecular expression by nasal mucosa, suggests that neither degradation of IL-1 nor downregulation of IL-1 receptors in nasal mucosa is likely to explain the inability of IL-1 to induce VCAM expression by nasal mucosa. These studies suggest that microvascular endothelial cells in the nasal mucosa differ functionally from HUVECs and that TNF may be more important than IL-1 in induction of VCAM expression in the nasal mucosa.

Cells, Cultured↗

PubMed1994

A phase I and pharmacokinetic study of intravenous phenylacetate in patients with cancer.

Phenylacetate has recently been shown to suppress tumor growth and promote differentiation in experimental models. A phase I trial of phenylacetate was conducted in 17 patients with advanced solid tumors. Each patient received a single i.v. bolus dose followed by a 14-day continuous i.v. infusion of the drug. Twenty-one cycles of therapy were administered at four dose levels, achieved by increasing the rate of the continuous i.v. infusion. Phenylacetate displayed nonlinear pharmacokinetics [Km = 105.1 +/- 44.5 (SD) microgram/ml, Vmax = 24.1 +/- 5.2 mg/kg/h and Vd = 19.2 +/- 3.3 L]. There was also evidence for induction of drug clearance. Ninety-nine % of phenylacetate elimination was accounted for by conversion to phenylacetylglutamine, which was excreted in the urine. Continuous i.v. infusion rates resulting in serum phenylacetate concentrations exceeding Km often resulted in rapid drug accumulation and dose-limiting toxicity, which consisted of reversible central nervous system depression, preceded by emesis. Three of nine patients with metastatic, hormone-refractory prostate cancer maintained stable prostatic specific antigen levels for more than 2 months; another had less bone pain. One of six patients with glioblastoma multiforme, whose steroid dosage has remained unchanged for the duration of therapy, has sustained functional improvement for more than 9 months. The use of adaptive control with feedback for the dosing of each patient enabled us to safely maintain stable phenylacetate concentrations up to the range of 200-300 micrograms/ml, which resulted in clinical improvement in some patients with advanced disease.

Adult↗

PubMed1994

Diagnostic localization studies for primary hyperparathyroidism. A suggested algorithm.

OBJECTIVE: To assess the accuracy of preoperative imaging studies in primary hyperparathyroidism. DESIGN: Retrospective review of all patients treated surgically for primary hyperparathyroidism at The University of California-San Diego Medical Center between January 1990 and May 1992. Results of preoperative imaging studies were compared with surgical and pathologic findings. SETTING: The University of California-San Diego Medical Center, a primary care and referral center. PARTICIPANTS: Twenty-eight patients were included in the study, and a total of 41 imaging studies were obtained. OUTCOME MEASURES: The accuracy of preoperative imaging studies in correctly localizing the site of a parathyroid adenoma. RESULTS: Ultrasound correctly identified the site of a solitary parathyroid adenoma in 82% of cases, and magnetic resonance imaging in 80% of cases. The adenomas that were not localized by ultrasound were correctly localized by magnetic resonance imaging. These findings are discussed within the context of recent trends in parathyroid surgery. CONCLUSIONS: Based on the results and a review of the literature, a simple algorithm for the use of these imaging studies is proposed. Use of this algorithm will improve preoperative planning, and potentially reduce operative time and morbidity.

Adenoma↗

PubMed1993

Fibrous hamartoma of infancy presenting as a perspiring neck mass.

An unusual case of fibrous hamartoma of infancy is reported. This lesion presented as a gradually enlarging, perspiring left neck mass in an eight month old male. Histologic examination revealed the characteristic features of this entity, with the additional finding of eccrine gland hyperplasia. In a review of the literature, we found no other reports of this unique histologic finding or clinical presentation.

Hamartoma↗

PubMed1992

Adaptive control with feedback strategies for suramin dosing.

Suramin, a drug used in the treatment of parasitic diseases, is currently being evaluated in clinical trials as an antineoplastic agent. The use of therapeutic drug monitoring and adaptive control with feedback in clinical trials of suramin was initially motivated by an association between acute neurologic toxicity and plasma suramin concentrations in excess of 350 micrograms/ml. We have prospectively examined the performance of both two- and three-compartment population pharmacokinetic models in controlling plasma suramin concentrations and have found that a three-compartment model best describes this drug. No correlation was found between the clearance of suramin and creatinine clearance, as had been previously hypothesized. The low systemic clearance of suramin and the number of parameters required to describe the three-compartment model suggest the need for a bayesian approach to the estimation of individual pharmacokinetics.

Adrenal Gland Neoplasms↗

PubMedDate not supplied

Fine-needle aspiration of parotid gland lesions.

The results of 49 specimens obtained by fine-needle aspiration biopsy of parotid gland lesions were compared with the pathologic diagnoses of the surgically resected specimens. Cytologically, 33 lesions were diagnosed as benign, with 30 of these confirmed histologically and three false-negative results. Fourteen cytologic specimens were called malignant or suspicious for malignancy, with 11 of these confirmed histologically and three false-positive results. The concurrence rate for distinguishing benign from malignant disease was 87.2%. The sensitivity for malignancy was 78.6% and the specificity 90.9%. The pathology of the misdiagnosed lesions will be reviewed. Based on our data and a review of the literature, we conclude that fine needle aspiration biopsy of parotid gland masses, with the observation of certain caveats, is a helpful adjunctive test for diagnosis and treatment planning.

Adolescent↗