Zidovudine in patients with human immunodeficiency virus (HIV) infection and Kaposi sarcoma. A phase II randomized, placebo-controlled trial

STUDY OBJECTIVE: To evaluate the toxicity, effects on immune function, antitumor effects, antiretroviral effects, and pharmacokinetics of zidovudine therapy in patients with early human immunodeficiency virus (HIV) infection and Kaposi sarcoma. DESIGN: Randomized, double-blind, placebo-controlled trial. SETTING: National Institutes of Health, a referral-based research institution (single site). PATIENTS: Physician-referred volunteer patients with HIV infection, Kaposi sarcoma, CD4+ lymphocyte counts greater than 0.2 x 10(9)/L, and no systemic symptoms or history of opportunistic infection. Of 41 patients enrolled, 4 had not met all entry criteria and were therefore not evaluable. INTERVENTIONS: Patients were randomized to one of four treatment groups for an initial 12-week treatment period: oral placebo (9 patients); zidovudine, 250 mg orally every 4 hours (9 patients); zidovudine, 0.5 mg/kg body weight intravenously every 4 hours (9 patients); and zidovudine, 2.5 mg/kg intravenously every 4 hours (10 patients). After at least 12 weeks of therapy at their assigned dose, patients were treated with oral zidovudine, generally 250 mg every 4 hours, with a mean 42-week follow-up. MEASUREMENTS AND MAIN RESULTS: Anemia and granulocytopenia were the major toxicities. Significant increases in platelet counts and declines in serum HIV antigen and IgG and IgM levels occurred in treated patients. Treated patients were more likely than those on placebo to clear HIV from the cerebrospinal fluid. There were no differences in tumor progression or CD4+ or CD8+ lymphocyte counts among the groups. CONCLUSIONS: Zidovudine was well tolerated and had antiretroviral activity in patients with early HIV infection and Kaposi sarcoma but it had no significant effect on the extent of Kaposi sarcoma or on immune function.     

The relationship between virus load response to highly active antiretroviral therapy and change in CD4 cell counts: A report from the Women's interagency HIV study

The relationship between the pattern of virus load response to highly active antiretroviral therapy (HAART) and CD4 lymphocyte response was assessed in a cohort of 249 human immunodeficiency virus (HIV) type 1-infected women at 3 times: 1 before and 2 after initiation of therapy, with follow-up of 6-12 months. Patients with a durable response to HAART (i.e., >1 log decrease in HIV-1 RNA sustained for the study periods) had a continuous and significant increase in CD4 cell counts over time, whereas those with no response (<0.5 log decrease in HIV-1 RNA) had a slight decline. Patients with a mixed response (initial decrease >1 log, followed by a subsequent decrease <0.5 log) had an increase in CD4 cell count, followed by a plateau. The trend in CD4 cell count differed significantly by response to HAART, with those patients who experienced a durable response having significantly higher CD4 cell counts than others.     

Effect of Gamma Knife Radiosurgery on a Pituitary Gonadotroph Adenoma: A Histologic,Immunohistochemical and Electron Microscopic Study

The morphologic findings in a pituitary macroadenoma removed from a 65-year old man by the transsphenoidal approach 9 months after gamma knife surgery are reported. The tumor was immunoreactive for FSH and showed ultrastractural features consistent with an oncocytic gonadotroph adenoma. Accumulation of connective tissue separating small groups of adenoma cells was evident. Several dilated vessels and numerous vascular endothelial growth factor immunopositive adenoma cell were noted. By electron microscopy the endothelial linings frequently showed discontinuities with platelet accumulation attached to the gaps. Several vessels were severely injured showing necrosis of endothelial cells. It can be concluded that gamma knife surgery caused severe alterations in pituitary adenoma microcirculation indicating that vascular injury plays a crucial role in tumor shrinkage.     

Polyamine metabolism in Pneumocystis carinii

Alpha-difluoromethylornithine (DFMO) is being used to treat Pneumocystis carinii pneumonia despite a lack of in vitro evidence supporting its antipneumocystis activity. DFMO is a specific inhibitor of ornithine decarboxylase, the rate-limiting enzyme of polyamine biosynthesis. To investigate polyamine metabolism in P. carinii, extracts of the organism were analyzed for polyamine content and ornithine decarboxylase activity, and [3H]ornithine and [14C]arginine incorporation into polyamines during short-term culture was determined. P. carinii extracts contained putrescine and spermidine in a ratio of 0.17:1; traces of spermine were detected. Although ornithine decarboxylase activity was not detected, P. carinii incorporated ornithine and arginine into putrescine and spermidine but not into spermine, suggesting that the spermine detected derived from contaminating host cells. Uninfected rat lung incorporated ornithine minimally. Pentamidine, DFMO, and alpha-monofluoromethyldehydroornithine methyl ester inhibited ornithine incorporation by up to 86% at clinically achievable concentrations. These data provide a rationale for using polyamine synthesis antagonists in P. carinii pneumonia and a method for screening antipneumocystis drugs in vitro.     

Silent Adenoma Subtype 3 of the Pituitary—Immunohistochemical and Ultrastructural Classification: A Review of 29 Cases

The silent adenoma subtype 3 (SAS-3) of undetermined cellular derivation is a seemingly nonfunctioning aggressive pituitary tumor with a high recurrence rate. At the time of diagnosis SAS-3s are macro- or giant adenomas particularly aggressive in young individuals, especially women. They are usually associated with mild hyperprolactinemia and are unremarkable by histology. Immunohistochemistry, demonstrating scattered immunoreactivity mostly for GH, PRL, TSH, and α-subunit, is not diagnostic. Presently, only TEM permits conclusive diagnosis. Ultrastructurally, the large polar adenoma cells contain abundant RER, masses of SER, extensive multipolar Golgi apparatus, and unevenly clustered mitochondria, displaced by RER and SER, which may show close spatial relationship to RER. Cell membranes often form plexiform interdigitations. Nuclear pleomorphism and nuclear inclusions are common. The 100- to 200-nm secretory granules accumulate heavily in cell processes, which is a hallmark of glycoprotein hormone cell differentiation. The endothelial cells may contain tubuloreticular inclusions. Complete surgical removal of the large often invasive tumors is difficult necessitating postoperative treatment. SAS-3 is sensitive to conventional radiation. Some tumors express somatostatin receptors and respond well to somatostatin analogues, offering long-term control in patients with residual tumor. Possible derivation of SAS-3 from rostral thyrotrophs, a cell type presently known in rodents is comtemplated.     

A novel temporal‐predominant neuro‐astroglial tauopathy associated with TMEM106B gene polymorphism in FTLD/ALS‐TDP

Polymorphisms in TMEM106B, a gene on chromosome 7p21.3 involved in lysosomal trafficking, correlates to worse neuropathological, and clinical outcomes in frontotemporal lobar degeneration (FTLD) and amyotrophic lateral sclerosis (ALS) with TDP‐43 inclusions. In a small cohort of C9orf72 expansion carriers, we previously found an atypical, neuroglial tauopathy in cases harboring a TMEM106B rs1990622 A/A genotype. To test whether TMEM106B genotype affects the risk of developing atypical tauopathy under a recessive genotype model (presence versus absence of two major alleles: A/A vs. A/G and G/G). We characterized the atypical tauopathy neuropathologically and determined its frequency by TMEM106B rs1990622 genotypes in 90 postmortem cases with a primary diagnosis of FTLD/ALS‐TDP [mean age at death 65.5 years (±8.1), 40% female]. We investigated the effect of this new atypical tauopathy on demographics and clinical and neuropsychological metrics. We also genotyped TMEM106B in an independent series with phenotypically similar cases. Sixteen cases (16/90, 17.7 %) showed the temporal‐predominant neuro‐astroglial tauopathy, and 93.7% of them carried an A/A genotype (vs. ~35% in a population cohort). The odds ratio of FTLD/ALS‐TDP individuals with the A/A genotype showing neuro‐astroglial tauopathy was 13.9. Individuals with this tauopathy were older at onset (p = 0.01). The validation cohort had a similarly high proportion of rs1990622 A/A genotype. TDP‐43 and tau changes co‐occur in a subset of neurons. Our data add to the growing body of evidence that TMEM106B polymorphisms may modulate neurodegeneration. A distinctive medial temporal predominant, 4‐repeat, neuro‐astroglial tauopathy strongly correlates to TMEM106B A/A genotype in FTLD/ALS‐TDP cases.     

Human fetal adenohypophysis. Electron microscopic and ultrastructural immunocytochemical analysis

The pituitary glands were removed from 63 human fetuses from 5 weeks of gestation to term and studied by electron microscopy and ultrastructural immunocytochemistry to document the development of cell differentiation and hormone production in the adenohypophysis. At 5 weeks of gestation, Rathke's cleft was lined by columnar epithelium with abundant cytoplasmic glycogen and occasional secretory granules. By 6 weeks of gestation, cells resembling corticotrophs were identified; in 8-week-old fetuses, type I microfilaments were found in those cells. Well-differentiated somatotrophs were seen in adenohypophyses of 8- to 9-week-old fetuses. Although secretory granules were numerous, the Golgi complex was inconspicuous in early fetal glands. After 10 weeks of gestation, there was a change with morphologic evidence of active hormone secretion; large Golgi regions and sparsely granulated cells were found. Some somatotrophs at this stage contained aggregates of type II microfilaments which resembled the fibrous bodies of sparsely granulated somatotroph adenomas. Densely granulated mammosomatotrophs containing growth hormone and prolactin were identified at 12 weeks of gestation. Cells with characteristics of the glycoprotein hormone cell line were seen in pituitaries at 12 weeks of gestation; thyrotrophs and gonadotrophs were identified after 15 weeks. Typical lactotrophs were not recognized before 23 weeks, but were numerous in pituitaries of fetuses older than 35 weeks. This study documents for the first time the existence of a bihormonal mammosomatotroph in the human fetal pituitary and confirms that somatotrophs and lactotrophs, the two acidophil cell types, are embryologically related.(ABSTRACT TRUNCATED AT 250 WORDS)