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Biomedical subjects

S Schantz

Publications and source records attributed to S Schantz.

14 recordsLinked to original sources
PubMed2001

Parotid and thyroid gland cancers in patients with ataxia-telangiectasia.

This study describes the clinicopathologic features of parotid and thyroid gland cancers in patients with ataxia-telangiectasia (AT). The medical records of 412 AT patients were reviewed to identify those patients who developed parotid or thyroid gland cancers. Presenting features, diagnoses, types of therapy, risk factors, and other primary cancers were analyzed. Five patients with parotid or thyroid gland cancers were identified. Three had parotid (2 mucoepidermoid and 1 acinic cell) and 2 had thyroid gland (1 papillary and 1 follicular) cancers. Four patients presented with head and neck masses and 1 had an occult papillary thyroid carcinoma. Four patients had more than one primary cancer. The only mode of therapy was surgery. The 2 patients with mucoepidermoid carcinoma had complete parotidectomies. One is alive without any evidence of disease 12 months after diagnosis and 1 died of refractory lymphoma without any evidence of mucoepidermoid carcinoma at autopsy. The patient with acinic cell carcinoma had a parotid biopsy only. The 2 patients with thyroid cancer were diagnosed at autopsy. The results indicate that patients with AT are at risk for developing multiple primary cancers including those of the parotid and thyroid gland, and should be evaluated for such primaries.

Adolescent↗
PubMed1999

Critical care for the severely ill head and neck patient.

OBJECTIVE: To delineate the frequency and causes of admission to a critical care environment for patients undergoing head and neck surgery at Memorial Sloan-Kettering Cancer Center. DESIGN: Retrospective clinical investigation. SETTING: Adult intensive care unit of a tertiary referral cancer center. PATIENTS: All head and neck surgery patients admitted to the special care unit (SCU) of Memorial Sloan-Kettering Cancer Center between January 1, 1994 and December 31, 1995 were included in this study. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The data collected included demographic, operative procedures, clinical, laboratory, and physiologic variables at time of SCU admission, at 24 hrs, as well as vital status at the time of discharge from the SCU and hospital. Other data collected were the need for mechanical ventilation and inotropic agents. During the period of January 1, 1994 through December 31, 1995, 37 (1.5%) of 2,346 patients undergoing head and neck surgical procedures required admission to the SCU. During the same period, six patients receiving medical treatment only for head and neck malignant disease were transferred to the SCU. These 43 admissions served as the basis for the study. The causes of admission to the SCU were pulmonary (15/43), cardiac (14/43), wound related (8/43), and other (15/43). The median length of stay in the SCU was 2 days, and the median hospitalization for patients requiring critical care services was 22 days. Seventy-four percent of patients requiring critical care services were eventually discharged to home. CONCLUSIONS: Current preoperative evaluation, operative and anesthetic techniques, and perioperative care result in a low frequency of utilization of critical care services by patients undergoing head and neck surgery. There is no single identifiable cause of complications for patients after head and neck surgery leading to utilization of critical care services.

Adolescent↗
PubMed1999

Characterization of potential endocrine-related health effects at low-dose levels of exposure to PCBs.

This article addresses issues related to the characterization of endocrine-related health effects resulting from low-level exposures to polychlorinated biphenyls (PCBs). It is not intended to be a comprehensive review of the literature but reflects workshop discussions. "The Characterizing the Effects of Endocrine Disruptors on Human Health at Environmental Exposure Levels," workshop provided a forum to discuss the methods and data needed to improve risk assessments of endocrine disruptors. This article contains an overview of endocrine-related (estrogen and thyroid system) interactions and other low-dose effects of PCBs. The data set on endocrine effects includes results obtained from mechanistic methods/ and models (receptor based, metabolism based, and transport protein based), as well as from (italic)in vivo(/italic) models, including studies with experimental animals and wildlife species. Other low-dose effects induced by PCBs, such as neurodevelopmental and reproductive effects and endocrine-sensitive tumors, have been evaluated with respect to a possible causative linkage with PCB-induced alterations in endocrine systems. In addition, studies of low-dose exposure and effects in human populations are presented and critically evaluated. A list of conclusions and recommendations is included.

Animals↗
PubMed1998

The radial forearm osteocutaneous "sandwich" free flap for reconstruction of the bilateral subtotal maxillectomy defect.

Complex resections of the maxilla produce a three-dimensional defect that can be difficult to reconstruct using autogenous tissue without utilizing a free tissue transfer. The osteocutaneous flaps that have been described for reconstruction of this area have been the scapula, iliac crest, and fibula, which are often hampered by their bulkiness and less than ideal intraoral lining. The bilateral subtotal maxillectomy defect is particularly difficult to reconstruct because it requires restoration of the bony framework of the midface as well as the restoration of the palatal and nasal lining. We present a new technique for reconstruction of this type of defect using the osteocutaneous radial forearm free flap. Two patients with bilateral subtotal maxillectomy defects, in whom the entire hard palate and maxillary arch were resected, underwent primary reconstruction. The bone from the osteocutaneous flap was osteotomized and contoured to recreate the maxillary arch. The large skin island was folded around the bone, as in a sandwich, and used to replace the palatal and nasal lining. This sandwiched osteocutaneous flap allowed for secure fitting of a dental prosthesis and the future possibility of osteointegrated implants. Long-term stability of the bone without retrusion was achieved with an excellent functional and aesthetic outcome. The radial forearm osteocutaneous free flap is ideal for the reconstruction of the maxillary infrastructure in that (1) it provides bone and thin, pliable skin in the correct proportions; (2) the described "sandwich" technique restores an excellent functional and aesthetic state; and (3) dental rehabilitation can be further improved by using either a prosthesis or osteointegrated implants.

Adult↗
PubMed1997

Polarization filter for biomedical tissue optical imaging.

A technique based on the degree that light is depolarized when propagating inside tissues is demonstrated for optical imaging in biomedical systems. The difference in the degree of polarization of the emerging light allows for the discrimination of different types of tissues. The technique was investigated in the transillumination and back-scattering geometry and in both cases the potential of this method to image and separate out different types of tissues is demonstrated.

Animals↗
PubMed1996

Relationship between p53 mutation incidence in oral cavity squamous cell carcinomas and patient tobacco use.

It is well-established that a high incidence of p53 mutations exist in oral cavity squamous cell carcinomas (OCSCCs). To determine whether p53 mutations are etiologically associated with OCSCC development or are associated with exposure to specific carcinogens, we have analyzed the conserved regions of the p53 gene (exons 5-9) in 48 OCSCCs obtained from patients with varied tobacco and alcohol use histories by polymerase chain reaction/single strand conformational polymorphism (PCR/SSCP) and DNA sequencing analysis. Thirty-eight percent (18/48) of the OCSCCs exhibited a mutation in exons 5-9 of the p53 gene. There was a significantly higher incidence of p53 mutations in OCSCCs from tobacco users (predominantly cigarette smokers) compared to those who had never used tobacco. No increase in the incidence of p53 mutation was observed in tobacco users who drank alcohol. G to A transitions and deletions were the predominant mutations observed in OCSCCs from tobacco users. No specific pattern of mutation was observed in OCSCCs from those subjects who had never used tobacco. These data suggest that a history of tobacco use was associated with a high incidence of p53 mutations in patients with OCSCC and that tobacco carcinogens include a specific pattern of mutations in oral cavity tissue in vivo.

Adult↗
PubMed1996

Simultaneous retroperitoneal, thoracic, and cervical resection of postchemotherapy residual masses in patients with metastatic nonseminomatous germ cell tumors of the testis.

PURPOSE: We report our experience with simultaneous resection of residual masses above and below the diaphragm in patients with metastatic nomseminomatous germ cell tumor (NSGCT) of the testis. MATERIALS AND METHODS: Twenty-four patients underwent simultaneous resection of residual postchemotherapy masses in the retroperitoneum and chest, including three who also had radical neck dissection. All had been heavily pretreated with chemotherapy and five had undergone previous retroperitoneal lymph node dissections (RPLNDs). RESULTS: The combined procedure was performed with no mortality and low morbidity. The median length of the procedure was 5 hours 45 minutes, median blood loss 500 mL, and median length of hospital stay 9 days. Complications included one patient with chylous ascites and one with a prolonged air leak, both of which resolved with conservative management. Eighteen patients had similar pathologic findings in all sites: 13 with necrosis only and five with teratoma only. Six patients had discordant pathology in the abdomen and chest, including one with viable tumor in the chest only and two with viable tumor in the abdomen only. The overall actuarial 5-year survival rate for all patients was 79%. CONCLUSION: Simultaneous resection of neck, chest, and abdominal residual masses after chemotherapy for germ cell tumors is both a feasible and safe alternative to staged excision in selected patients who require surgical intervention at multiple sites and fulfills the objective of rendering patients disease-free in a single operative procedure.

Adolescent↗
PubMed1995

Emerging role of beta-carotene and antioxidant nutrients in prevention of oral cancer.

beta-carotene and other antioxidant nutrients, such as vitamin E, are well suited for widespread preventive use because they are nontoxic and easily given in supplement form. Intervention trials designed to show a reduction of cancer incidence in the general population are logistically and practically impossible for most types of cancer, including cancer of the oral cavity. Thus evidence for chemoprevention must be indirect, using laboratory and animal models, epidemiologic surveys, and trials showing reversal of premalignant lesions or cancer prevention in high-risk groups. In several animal models, beta-carotene and other antioxidant nutrients inhibit oral carcinogenesis. Epidemiologic studies consistently relate low intake of these nutrients with high cancer risk. Smokers have lower beta-carotene levels in plasma and oral mucosal cells than nonsmokers. Eight clinical trials have now shown that beta-carotene and vitamin E produce regression of oral leukoplakia, but chemoprevention studies in oral leukoplakia have limitations, which we review. All available evidence supports a significant role for antioxidant nutrients in preventing oral cancer.

Animals↗
PubMed1994

Tissue autofluorescence as an intermediate endpoint in NMBA-induced esophageal carcinogenesis.

The capacity to identify subclinical neoplastic disease of the upper aerodigestive tract (UADT) using tissue auto-fluorescent spectroscopy would significantly contribute to cancer screening. Rats received N-nitrosomethyl benzylamine (NMBA), a carcinogen shown to cause esophageal malignancies. Following sacrifice at early weekly intervals, gross assessment of esophageal mucosa of NMBA-exposed rats was indistinguishable from saline-treated controls. Histopathologic evaluation, however, revealed NMBA-induced preneoplastic changes in the epithelium. Concurrent with these changes, the NMBA-exposed rats demonstrated specific alterations in autofluorescence. These results demonstrate that NMBA-induced esophageal premalignancy can be distinguished by autofluorescent properties. The capacity to detect alterations in autofluorescence may allow more sensitive screening of UADT mucosa at risk for cancer development.

Animals↗
PubMedDate not supplied

Electrosurgical dissection to reduce blood loss in head and neck surgery.

We prospectively determined the intraoperative blood loss in 250 patients who underwent major head and neck surgical procedures over a 13-month period to demonstrate the efficacy of electrosurgical dissection for reducing blood loss and to determine those factors predictive of the need for blood replacement. Transfusions were required in 30 (12%) of the 250 patients, and a total of 66 units of packed red blood cells was administered. Two patients were transfused preoperatively, 16 patients intraoperatively, and 14 patients postoperatively. Factors predicting the necessity for blood replacement included the patient's preoperative hematocrit level, intraoperative blood loss, the duration and type of procedure, and the surgeon's level of experience. The principles of electrosurgical dissection are discussed.

Adolescent↗
PubMedDate not supplied

Chemoprevention of aerodigestive cancer.

Effective chemoprevention of aerodigestive tumors could have far-reaching effects. Aerodigestive cancer accounts for one-third of all cancer deaths in the United States and is the most common cancer in some areas of the world. Prognosis is poor, and a reduced quality of life remains in those who do survive. To date, there have been no effective chemopreventive agents, but many new compounds hold promise. The concepts of field carcinogenesis and multi step carcinogenesis underpin the development of chemopreventive agents for aerodigestive tract tumors. Important risk factors are tobacco use, alcohol consumption, dietary habits, genetic susceptibility, socioeconomic status, and the interaction of these. Two promising areas for surrogate biomarker development are tissue autofluorescence and DNA repair. Numerous chemoprevention trials have shown that antioxidant compounds are effective in reversing precursor lesions. Studies of the effects of chemopreventive agents on second primary tumors are ongoing. Finally, large-scale trials of the anti-oxidant beta carotene have been disappointing; they have shown that among heavy smokers and possibly heavy alcohol consumers beta carotene increases risk for lung cancer incidence and mortality. These findings underline the critical need to better understand specific mechanisms of action at a particular tissue site, and under various conditions, such as heavy smoking. Novel agents are under development: epigallacatchin gallate, or green tea, curcumin, and a new emphasis on folic acid. Studies to date show that targeting susceptible subgroups, by means of genetic or lifestyle factors, and all ethnic groups will facilitate the goals of chemoprevention studies.

Anticarcinogenic Agents↗
PubMedDate not supplied

Hormonal interactions in the effects of halogenated aromatic hydrocarbons on the developing brain.

Halogenated arylhydrocarbons (HAHs) exert a wide range of effects on the developing brain. These effects result in altered patterns of neuroendocrine function and behavior in adulthood, as well as changes in cognitive function. The underlying mechanisms have not yet been clearly defined. This paper briefly reviews the effects of HAHs on brain development, and proposes the hypothesis that interactions between different hormone-sensitive systems may contribute to the broad spectrum of responses observed after fetal or early postnatal HAH exposure. Physiological interactions between the effects of sex steroids, corticosteroids, and thyroid hormone are known to influence the development of the central nervous system (CNS). Since the biosynthesis and/or action of each of these hormones is sensitive to developmental HAH exposure, it is suggested that convergent effects of HAHs on different endocrine pathways may underlie some of the disruptive effects of these chemicals on CNS differentiation. Data are presented indicating that the disruptive effects of low dose dioxin exposure on sexual differentiation of the rat brain are probably not mediated through blockade of estrogen responses, but may instead involve subtle developmental changes in other endocrine systems, perhaps also affecting the feedback control of adrenocortical function. The potential for interactive endocrine effects illustrates the need for a fuller understanding of the range of biological activities of HAHs in the brain, so that the potential risks of low dose developmental exposure to these environmental toxicants can be predicted with greater certainty.

Adrenal Cortex Hormones↗