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Biomedical subjects

F Torriani

Publications and source records attributed to F Torriani.

4 recordsLinked to original sources

Human immunodeficiency virus replication in AIDS patients with Mycobacterium avium complex bacteremia: a case control study. California Collaborative Treatment Group.

The development of opportunistic infections and the administration of vaccines have been associated with transient increases of human immunodeficiency virus (HIV) RNA plasma levels in HIV-infected patients. To determine the relationship between Mycobacterium avium complex (MAC) bacteremia and HIV RNA levels, HIV RNA levels in patients who developed MAC bacteremia (cases) were compared with levels in patients who remained free of MAC disease (controls). Cases and controls were matched for CD4 cell count, prophylaxis against MAC disease, antiretroviral therapy, and duration of follow-up. Mean baseline HIV RNA levels were 4.8 log10 copies/mL in cases and 4.6 log10 copies/mL in controls (P = 0.22). HIV RNA levels increased by a median of 0.4 log in cases but not controls at the time of MAC bacteremia (P = 0.01). In AIDS patients, the onset of MAC bacteremia is associated with a modest but significant increase in serum HIV RNA levels. Increased HIV replication may contribute to the higher mortality associated with MAC bacteremia.

AIDS-Related Opportunistic Infections↗

In vivo compartmentalization of human immunodeficiency virus: evidence from the examination of pol sequences from autopsy tissues.

High rates of mutation and replication of human immunodeficiency virus (HIV) allow for the continuous generation of diverse genetic variants in vivo. Selective pressures within the microenvironments of different anatomic compartments result in the emergence of dominant quasispecies which can be distinguished by their envelope sequences. It is not known whether comparable tissue-specific selective pressures lead to the independent evolution of pol sequences within different tissue compartments, nor is it known how differing rates of virus turnover in tissues might affect the pace of such evolution. These issues are of importance for the formulation of a model for the emergence of drug resistance in vivo and for a general understanding of virus trafficking and virus turnover. Regions of the HIV type 1 reverse transcriptase (RT) which carry the majority of the known resistance codons to RT inhibitors (700 nucleotides from each clone) were cloned and sequenced directly from autopsied brain, spleen, and lymph node specimens from four subjects who had received zidovudine therapy. Clones from proviral DNA (143) and from viral cDNA (14) were analyzed. In three of four subjects, a discordance in distribution of resistance codons was noted. Moreover, brain-derived sequences appeared to be phylogenetically distinct from spleen- and lymph node-derived sequences even after exclusion of resistance codons from analysis. In each case, evidence for differential immune selective pressure, based on comparison of inferred amino acid sequences corresponding to known major histocompatibility complex class I cytotoxic T-lymphocyte epitopes, was found. These observations support the concept of anatomically distinct, independently evolving quasispecies (virodemes).

Acquired Immunodeficiency Syndrome↗

Pancreatic insuloma causing Cushing's syndrome.

The advent of new diagnostic procedures such as petrosal venous sampling and CRF testing has improved the possibilities of precise location of the site of hormonal overproduction in Cushing's syndrome. We report on a case of ectopic ACTH-dependent Cushing's syndrome in which the use of such techniques helped to locate the tumor. A 45-year-old woman with definite ACTH-dependent Cushing's syndrome was referred to our clinic for evaluation. ACTH, cortisol and urinary 17OHCS failed to suppress on high dose dexamethasone oral administration. Computerized tomography showed bilateral adrenal hyperplasia and an empty sella turcica. ACTH and cortisol did not increase after CRF administration. Staged caval system catheterism via both femoral veins up to the inferior petrosal sinuses, including after CRF administration, demonstrated no ACTH gradient between staged samples and simultaneous peripheral venous blood. This suggested a tumor drained by the portal system. An abdominal ultrasonography demonstrated a pancreatic mass, that was surgically excised and appeared as a benign islet cell tumor. Portal vein ACTH promptly decreased after tumor excision and postoperative peripheral cortisol and ACTH were normal. On immunostaining the tumor cells proved to be positive for ACTH.

ACTH Syndrome, Ectopic↗