Incarceration and the acquired immunodeficiency syndrome: Autopsy results in Texas prison inmates

The Texas Department of Criminal Justice (TDCJ) houses many subjects with acquired immunodeficiency syndrome (AIDS) who receive medical care in a comprehensive AIDS treatment center. In this case-control autopsy survey, we compared pathological outcomes of TDCJ inmates treated at the center (n = 155) with nonincarcerated patients who died during the same period (n = 155). Using multiple regression analysis and a proportional hazards model, survival time in the prisoners was equivalent to that in the controls. With few exceptions, the prevalences of opportunistic viral, fungal, protozoal, and bacterial infections contributing to mortality were equivalent between groups. Mycobacterium tuberculosis was isolated more frequently in the inmates, and M avium intracellulare was isolated less frequently (P < .0001). The inmates had a higher prevalence of bacterial infection of the central nervous system (CNS) (9.1% v 1.4%; P < .006); half of all CNS bacterial infections were caused by M tuberculosis. Inmates had significantly lower prevalences of vacuolar myelopathy (P < .006) and severe wasting disease (P < .0009). We conclude that survival of prison inmates with AIDS treated in a comprehensive AIDS treatment center was equivalent to that of nonincarcerated subjects with AIDS. Prevalences of certain complications of AIDS differed in the inmates, showing that the prison environment influenced some of the underlying causes of AIDS morbidity and mortality.     

Joint Photographic Experts Group (JPEG) compatible data compression of mammograms

We have developed a Joint Photographic Experts Group (JPEG) compatible image compression scheme tailored to the compression of digitized mammographic images. This includes a preprocessing step that segments the tissue area from the background, replaces the background pixels with a constant value, and applies a noise-removal filter to the tissue area. The process was tested by performing a just-noticeable difference (JND) study to determine the relationship between compression ratio and a reader's ability to discriminate between compressed and noncompressed versions of digitized mammograms. We found that at compression ratios of 15∶1 and below, image-processing experts are unable to detect a difference, whereas at ratios of 60∶1 and above they can identify the compressed image nearly 100% of the time. The performance of less specialized viewers was significantly lower because these viewers seemed to have difficulty in differentiating between artifact and real information at the lower and middle compression ratios. This preliminary study suggests that digitized mammograms are very amenable to compression by techniques compatible with the JPEG standard. However, this study was not designed to address the efficacy of image compression process for mammography, but is a necessary first step in optimizing the compression in anticipation of more elaborate reader performance (ROC) studies.     

Visceral leishmaniasis in the acquired immunodeficiency syndrome: Report of two cases

Core biopsies of the bone marrow are indispensable in the evaluation of fever of unknown etiology in human immunodeficiency virus-positive patients. We report two patients in whom visceral leishmaniasis was diagnosed based on the typical morphology, staining characteristics, and ultrastructure of the organisms.     

The role of the complement system in innate immunity

Complement is a major component of innate immune system involved in defending against all the foreign pathogens through complement fragments that participate in opsonization, chemotaxis, and activation of leukocytes and through cytolysis by C5b-9 membrane attack complex. Bacterias and viruses have adapted in various ways to escape the complement activation, and they take advantage of the complement system by using the host complement receptors to infect various cells. Complement activation also participates in clearance of apoptotic cells and immune, complexes. Moreover at sublytic dose, C5b-9 was shown to promote cell survival. Recently it was also recognized that complement plays a key role in adaptive immunity by modulating and modifying the T cell responses. All these data suggest that complement activation constitutes a critical link between the innate and acquired immune responses.     

Somatic von hippel-lindau mutation in clear cell papillary cystadenoma of the epididymis

Papillary cystadenoma of the epididymis is an uncommon benign lesion that may occur sporadically or as a manifestation of von Hippel—Lindau (VHL) disease. Neither immunohistochemical studies nor molecular genetic analyses of the VHL gene have been reported previously for this lesion. The authors describe two cases of clear cell papillary cystadenoma of the epididymis, both of which were initially confused with metastatic renal cell carcinoma. Both lesions showed positive immunohistochemical staining for low and intermediate molecular weight keratins (Cam 5.2 and AE1/AE3), EMA, vimentin, α₁-antitrypsin, and α₁-antichymotrypsin. Each was negative for CEA. Because clear cell papillary cystadenoma is similar to renal cell carcinoma histologically, and because both occur as components of the von Hippel—Lindau disease complex, the authors analyzed both cases for the presence of mutations in the VHL gene. A somatic VHL gene mutation was detected in one of the two tumors by polymerase chain reaction followed by single-strand conformation polymorphism analysis. Direct sequencing revealed a cytosine to thymine transition at nucleotide 694, resulting in the replacement of an arginine with a stop codon after the sixth amino acid of exon 3. As the VHL gene is believed to function as a tumor suppressor gene, VHL gene mutations may play a role in the initiation of tumorigenesis in sporadic cystadenomas of the epididymis.     

Genotype-phenotype correlation in von Hippel-Lindau families with renal lesions

von Hippel-Lindau (VHL) disease arises from mutations in the VHL gene and predisposes patients to develop a variety of tumors in different organs. In the kidney, single or multiple cysts and renal cell carcinomas (RCC) may occur. Both inter- and intrafamilial heterogeneity in clinical expression are well recognized. To identify VHL-dependent genetic factors, we investigated the renal phenotype in 274 individuals from 126 unrelated VHL families in whom 92 different VHL mutations were characterized. The incidence of renal involvement was increased in families with mutations leading to truncated protein (MLTP) or large rearrangement, as compared to families with missense changes (81 vs. 63%, respectively; P=0.03). In the latter group, we identified two mutation cluster regions (MCRs) associated with a high risk of harboring renal lesions: MCR-1 (codons 74-90) and MCR-2 (codons 130-136). In addition, the incidence of RCC was higher in families with MLTP than in families with missense changes (75 vs. 57%; P=0.04). Furthermore, mutations within MCR-1 but not MCR-2 conferred genetic susceptibility to develop RCC. Overall, our data argued for a substantial contribution of the genetic change in the VHL gene to susceptibility to renal phenotype in VHL patients.