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Biomedical subjects

D Klotz

Publications and source records attributed to D Klotz.

11 recordsLinked to original sources
PubMed1999

An approach to the development of quantitative models to assess the effects of exposure to environmentally relevant levels of endocrine disruptors on homeostasis in adults.

The workshop "Characterizing the Effects of Endocrine Disruptors on Human Health at Environmental Exposure Levels" was held to provide a forum for discussions and recommendations of methods and data needed to improve risk assessments of endocrine disruptors. This article was produced by a working group charged with determining the basic mechanistic information that should be considered when designing models to quantitatively assess potential risks of environmental endocrine disruptors in adults. To reach this goal, we initially identified a set of potential organ system toxicities in males and females on the basis of known and/or suspected effects of endocrine disruptors on estrogen, androgen, and thyroid hormone systems. We used this integrated, systems-level approach because endocrine disruptors have the potential to exert toxicities at many levels and by many molecular mechanisms. Because a detailed analysis of all these untoward effects was beyond the scope of this workshop, we selected the specific end point of testicular function for a more detailed analysis. The goal was to identify the information required to develop a quantitative model(s) of the effects of endocrine disruptors on this system while focusing on spermatogenesis, sperm characteristics, and testicular steroidogenesis as specific markers. Testicular function was selected because it is a prototypical integrated end point that can be affected adversely by individual endocrine disruptors or chemical mixtures acting at one specific site or at multiple sites. Our specific objective was to gather the information needed to develop models in the adult organism containing functional homeostatic mechanisms, and for this reason we did not consider possible developmental toxicities. Homeostatic mechanisms have the potential to ameliorate or lessen the effects of endocrine disruptors, but these pathways are also potential target sites for the actions of these chemicals.

Adult↗
PubMed1998

HIV prevention with male prostitutes and patrons of hustler bars: replication of an HIV preventive intervention.

The core objectives of this study were to document the process by which a community-based organization replicated and adapted an experimentally developed intervention to its own use and to explore the effectiveness of that HIV prevention program for male prostitutes and other patrons in New York City "hustler" bars. The intervention model employed was based on previous research with gay men (Kelly, St. Lawrence, Diaz, et al., 1991; Kelly, St. Lawrence, Stevenson, et al., 1992) and inspired by diffusion of innovation theory (Rogers, 1995). The effects of the current intervention were assessed on a sample of 1,741 male prostitutes and bar patrons. Analyses indicated significant reductions in paid, unprotected sexual intercourse and oral sex following the intervention. Analyses further indicated that the data were partially consistent with the program's model, which specified that norms were the putative mediator of behavior change in the intervention. Also, the intervention's effects varied by bar and by participants' race/ethnicity. Data support the utility of the intervention model for an urban sample of men at high risk for HIV infection. The importance of exploring the mechanisms that underlie the intervention is discussed.

Adolescent↗
PubMed1997

Pearls and perils in the management of prolonged, peculiar, penetrating esophageal foreign bodies in children.

BACKGROUND/PURPOSE: Most retained esophageal foreign bodies (FB) are identified soon after ingestion and are easily extracted. A minority of FB ingestions are not identified for weeks to years and present significant problems for retrieval. The purpose of this study was to describe the diagnostic and therapeutic strategies needed to care for children who have chronic esophageal FBs. METHODS: Five children were identified as having retained esophageal FBs 2 months to 2 years after ingestion. During the same 3-year period, 100 children who had acute FBs were identified and had their foreign bodies removed endoscopically. The average age of the children was 3 years (range, 2.4 to 3.5). RESULTS: The average age of the five children identified in this study was 3 years. The items ingested included coins, a heart pendant, a clothespin spring, and a toy soldier. Complications from chronically retained foreign bodies were bronchoesophageal fistula, mediastinitis, esophageal diverticulum, and lobar atelectasis. One patient died from an aortoesophageal fistula. In all children, endoscopic removal was attempted. Barium esophagram was then performed, and foreign bodies were eventually removed via right thoracotomy. CONCLUSIONS: Long-retained esophageal FBs are extremely morbid and life threatening. History most often identifies excess salivation, new onset asthma, and/or recurrent upper respiratory infections. Three diagnostic adjuncts are helpful in identifying the presence of a long retained FB: (1) Chest x-ray (PA and lateral), (2) barium swallow, and (3) esophagoscopy. Indications for thoracotomy for removal of foreign body include (1) Poor endoscopic visualization of FB because of inflammatory tissue and (2) Herald bleeding during endoscopy.

Aorta, Thoracic↗
PubMed1993

Skeletal muscle metastasis in a patient with Wilms tumor and multiple late recurrences.

Stage III Wilms tumor was diagnosed in a 9-year-old girl. Four and a half years after the treatment, which consisted of an operation, radiation therapy, and chemotherapy, the patient had a solitary metastasis in the liver, which was successfully treated with chemotherapy and surgical resection. Five years later, right lung metastases were eradicated by chemotherapy, radiation, and surgical resection. Three and a half years later, she had a metastasis in the left calf, for which she underwent surgical resection and received chemotherapy. This patient has several interesting features: (1) multiple recurrences, two in the usual sites of metastasis and one in an extremely rare site, i.e., skeletal muscle; (2) long intervals between recurrences; and (3) unusual histopathologic features, i.e., gradual evolution from a triphasic Wilms tumor at the primary site, to a predominance of differentiated mucinous epithelium in the skeletal muscle metastasis.

Child↗
PubMed1975

Liver trauma in children.

A review of our experience with urban children who sustained blunt abdominal trauma revealed that liver trauma occurred in one-third of all children. The cause of trauma, predominantly blunt in nature, led to a multitude of associated injuries which not only caused visceral and skeletal injury endangering the patient, but, more apparent even though less significant injuries delayed diagnosis and therapy of the underlying sever liver injury. Awareness of the possibility of liver injury in children with blunt abdominal trauma, prompt operative intervention wil injuries should significantly increase the salvage of these pediatric trauma victims.

Accidents↗