Environmental epidemiologic issues and minority health

There exist great differences in morbidity and mortality across racial, cultural, and socioeconomic groups. Certain factors, like limited access to health care, are known to contribute to these differences. The contribution of other factors, like disparities in exposure to environmental hazards, is largely unknown as to the effect on minority groups' morbidity and mortality. This article describes select environmental hazards faced by minorities, such as lead toxicity in children, proximity to hazardous waste sites, and consumption of food contaminated with toxic substances, as well as the role of epidemiologists in documenting adverse health effects and participation in interventions to prevent them.

Serum and blister fluid pharmacokinetics and bactericidal activities of ampicillin-sulbactam, cefotetan, cefoxitin, ceftizoxime, and ticarcillin-clavulanate

Ampicillin-sulbactam, ticarcillin-clavulanate, cefoxitin, cefotetan, and ceftizoxime are promoted for the treatment of mixed aerobic-anaerobic bacterial infections. Their activities have been compared in vitro but not in vivo. In order to assess the in vivo activities of these agents in serum and interstitial fluid, we administered single, intravenous doses of these antimicrobial agents to healthy subjects. Concentrations of the antimicrobial agents in serum and suction-induced blister fluid and bactericidal activity were measured by high-pressure liquid chromatography and the standard methodology of the National Committee for Clinical Laboratory Standards, respectively. The organisms used for bactericidal activity tests were one isolate each of Staphylococcus aureus, Klebsiella pneumoniae, and Bacteroides fragilis. Pharmacokinetic parameters in serum and blister fluid were similar to those derived in other investigations. Of note were the high and prolonged concentrations of ticarcillin and cefotetan in blister fluid, despite high-level serum protein binding. The bactericidal activities in serum and blister fluid reflected the relative in vitro activities and kinetic dispositions of the various antimicrobial agents except for the bactericidal activity of cefotetan, which was substantially lower in blister fluid than serum, despite a blister fluid:serum area under the concentration-time curve ratio of 1.5. Similarly, the activity of ticarcillin-clavulanate in blister fluid was also substantially less than would have been predicted by the blister fluid:serum ratio of the area under the concentration-time curve of 1.1, possibly because of the low concentrations of clavulanate in blister fluid. The rankings of the in vivo bactericidal activities of the five drugs were as follows: for S. aureus, ampicillin-sulbactam > ticarcillin-clavulanate > ceftizoxime > cefoxitin > cefotetan; for K. pneumoniae, ceftizoxime > cefotetan > ampicillin-sulbactam = ticarcillin-clavulanate > cefoxitin; and for B.fragilis, ticarcillin-clavulanate > cefotetan > ceftizoxime > ampicillin-sulbactam = cefoxitin.

Signet cell melanocytic lesions

Malignant melanoma can produce diagnostic problems for the histopathologist because of its protean histologic patterns. The recently recognized signet cell pattern can be particularly confusing and must be distinguished from adenocarcinoma, tumors of vascular endothelium or adipose tissue, lymphoma, and epithelioid smooth muscle lesions. We report four new cases of signet cell melanoma and illustrate this pattern in primary as well as metastatic sites. In addition, we document the signet cell pattern in benign nevi for the first time, expanding the concept of this pattern to melanocytic cells in general. The differential diagnosis of signet cell melanoma and its mimics is discussed and the utility of immunohistochemical stains in this diagnosis is stressed.

Intraocular and central nervous system lymphoma in a cardiac transplant recipient

BACKGROUND

Although B-cell lymphomas are the most frequent cancers that evolve in transplant patients, histopathologic verification of intraocular lymphoma as a result of cyclosporine immunosuppression has not been previously recognized.

METHODS

A complete autopsy was performed on a 67-year-old woman who died 33 months after orthotopic heart transplantation.

FINDINGS

Large cell lymphoma extensively involved the anterior segment of the left eye, as well as the vitreous, retina, subretinal pigment epithelial zone, and optic nerve. Tumor also was found in the ipsilateral orbitofrontal cortex and hypothalamic areas. No systemic lymphoma was present.

CONCLUSION

Ocular and central nervous system lymphoma developed in a heart transplant patient. In addition to opportunistic infections, ophthalmologists should be aware that opportunistic lymphoproliferative disorders involving the eye and brain can occur in these immunosuppressed individuals. Epstein-Barr virus infection has been implicated as playing a major role.

Transmesosigmoid hernia during pregnancy

We have presented a case of internal herniation of small bowel through the sigmoid mesocolon in a pregnant woman. In patients with symptoms suggestive of bowel obstruction, even without a history of previous abdominal surgery, internal hernia must be included in the differential diagnosis.

Pharmacokinetic disposition and bactericidal activities of cefepime, ceftazidime, and cefoperazone in serum and blister fluid

Cefepime is a new broad-spectrum cephalosporin with excellent gram-positive and gram-negative activity including activity against Staphylococcus aureus, Pseudomonas aeruginosa, and Enterobacter cloacae. The pharmacokinetic disposition of cefepime is similar to that of ceftazidime. We compared the pharmacokinetic characteristics and the extent and duration of bactericidal activity in serum and suction-induced blister fluid after single 2-g intravenous doses of cefepime, ceftazidime, and cefoperazone given to healthy subjects. One clinical isolate each of E. cloacae, P. aeruginosa, and S. aureus was used to assess bactericidal activity. Results of the pharmacokinetic analysis were similar to previously reported data for these drugs. The high serum protein binding of cefoperazone (approximately 90%) contributed to poor blister fluid penetration. The other drugs penetrated well into this fluid compartment. Cefepime showed significantly greater bactericidal activity in serum and blister fluid against E. cloacae than the other study drugs, ceftazidime was significantly better in serum and blister fluid against P. aeruginosa, and cefoperazone was significantly better against S. aureus only in serum. None of the study drugs had significant bactericidal activity in blister fluid against S. aureus. Cefepime is a promising antimicrobial agent for the treatment of infections due to E. cloacae.

Endometriosis mimics general surgical disease

Endometriosis is rarely encountered by the general surgeon but may on occasion mimic general surgical disease. Although usually diagnosed easily because of cyclic symptoms and typical physical findings, six atypical cases are presented. These cases were diagnosed as appendicitis (2), subcutaneous mass (2), pelvic wall malignancy, and lower gastrointestinal hemorrhage. Diagnosis was ultimately made by laparotomy or excisional biopsy in five cases and by fine needle aspiration in one. Resection of the lesion, if feasible, is often curative. If resection is not feasible, therapy depends on the severity of the symptoms, and the patient's desire for fertility. Recognition of the typical appearance of an endometrioma may avoid mistaking it for cancer.

Ocular pathologic features of arteriohepatic dysplasia (Alagille's syndrome)

Arteriohepatic dysplasia (Alagille's syndrome), an autosomal dominant condition involving jaundice caused by a developmental scarcity of intrahepatic bile ducts, has characteristic cardiovascular, skeletal, facial, and ocular features that distinguish it from extrahepatic biliary atresia and an array of other neonatal intrahepatic cholestatic disorders. Two children who died of this syndrome had prominent Schwalbe's rings with attached iris strands characteristic of Axenfeld's syndrome. Additional histologic findings of iris atrophy and stromal nodules, however, made the designation Axenfeld-Reiger's syndrome more appropriate. Pigmentary retinopathy, degeneration of Bruch's membrane, and prominent lipofuscin deposition in the ciliary muscle noted in one of the patients were not regarded as primary changes of Alagille's syndrome, but were believed to be secondary to acquired deficiency of the fat-soluble vitamins A and E. Early recognition of the ocular changes in arteriohepatic dysplasia is helpful in establishing the proper diagnosis to avoid unnecessary abdominal surgery and institute vitamin therapy.

Pseudoepitheliomatous hyperplasia following Mohs micrographic surgery

Pseudoepitheliomatous hyperplasia may arise secondarily in a number of cutaneous disorders. Herein we discuss this entity and describe its occurrence in a post Mohs micrographic surgery wound. We will also relate the subsequent histopathologic confusion engendered by its presence.

Treatment of cutaneous granulocytic sarcoma in a patient with myelodysplasia

In this report, we have presented our experience with a patient with a rare cutaneous granulocytic sarcoma. In addition to hematoxylin and eosin, myeloperoxidase stain and specific stains for lysozyme and esterase were helpful in confirming the histologic diagnosis of granulocytic sarcoma. Despite multiple attempts to control this patient's tumor by conservative surgery, radiation therapy, and chemotherapy, we eventually had to resort to limb amputation. This procedure restored a meaningful quality of life to this patient for one and a half years prior to the development of acute leukemia. Treatment with corticosteroids at the time of surgery may have prevented a local recurrence of granulocytic sarcoma despite positive tissue margins. Our experience underscores the importance of directing treatment toward the granulocytic sarcoma whereas the myelodysplasia concurrently present may not require therapy for several years.