Vascular Endothelial Growth Factor/Vascular Permeability Factor Is Temporally and Spatially Correlated with Ocular Angiogenesis in a Primate Model

Ischemia often precedes neovascularization. Inocular neovascularization, such as occurs in diabetic retinopathy, a diffusible angiogenic factor has been postulated to be produced by ischemicretina and to lead to neovascularization of theretina, optic nerve, or iris. However, no angiogenic factor has been conclusively identified that satisfies this hypothesis. Vascular endothelial growth factor/vascular permeability factor, hereafter referred to as VEGF, is a likely candidate for an ocular angiogenic factor because it is a secreted mitogen, specific for endothelial cells, and is upregulated by hypoxia. We investigated the association of VEGF with the development of experimental iris neovascularization in the cynomolgus monkey. Following theproduction of retinal ischemia by laser occlusion of all branch retinal veins, VEGF was increased in the aqueous fluid, and the aqueous VEGF levels changed synchronously and proportionally with the severity of iris neovascularization. Northern analysis and in situ hybridization revealed that VEGF messenger RNA is upregulated in the ischemic retina. These observations support the hypothesis that ocular neovascularization is regulated by a diffusible factor and identify VEGF as a likely candidate for a retina-derived vascular permeability and angiogenesis factor in vivo.     

Distinct roles of type I bone morphogenetic protein receptors in the formation and differentiation of cartilage

The bone morphogenetic proteins (BMPs), TGFβ superfamily members, play diverse roles in embryogenesis, but how the BMPs exert their action is unclear and how different BMP receptors (BMPRs) contribute to this process is not known. Here we demonstrate that the two type I BMPRs, BMPR-IA and BMPR-IB, regulate distinct processes during chick limb development. BmpR-IB expression in the embryonic limb prefigures the future cartilage primordium, and its activity is necessary for the initial steps of chondrogenesis. During later chondrogenesis, BmpR-IA is specifically expressed in prehypertrophic chondrocytes. BMPR-IA regulates chondrocyte differentiation, serving as a downstream mediator of Indian Hedgehog (IHH) function in both a local signaling loop and a longer-range relay system to PTHrP. BMPR-IB also regulates apoptosis: Expression of activated BMPR-IB results in increased cell death, and we showed previously that dominant-negative BMPR-IB inhibits apoptosis. Our studies indicate that in TGFβ signaling systems, different type I receptor isoforms are dedicated to specific functions during embryogenesis.     

Unusual Enterobacteriaceae: a Salmonella cubana that is Urease Positive

This is the first report of a naturally occurring Salmonella that is urea positive. The strain was identified as Salmonella cubana and it was typical in all biochemical, serological, and bacteriophage reactions, except that is produced urease strongly.     

A general method for the calculation of serological specificity

A mathematically defined extension of Landsteiner's concept of serological specificity is given. It is a general method that compares the relative specificity of two antisera. The resultant comparison is independent of the relative potencies of the antisera. It is valid for antisera prepared either against pure antigens or against mixtures of antigens.

The method has been applied to data taken from the literature, involving haemagglutination, precipitin and enzyme reactions, and to new experimental data. Rabbit antisera were prepared against mouse erythrocytes and lymphocytes, and against three mouse ascites tumours. The potencies of these unabsorbed antisera were determined by immune cytolysis against each of these cell types. All antisera possessed moderate to strong cytolytic potencies against all mouse cells tested, but showed only low to moderate specificities.

     

Decreased hypocretin-1 (Orexin-A) levels in the cerebrospinal fluid of patients with myotonic dystrophy and excessive daytime sleepiness

STUDY OBJECTIVE: Myotonic dystrophy type 1 is a multisystem disorder with myotonia, muscle weakness, cataracts, endocrine dysfunction, and intellectual impairment. This disorder is caused by a CTG triplet expansion in the 3' untranslated region of the DMPK gene on 19q13. Myotonic dystrophy type 1 is frequently associated with excessive daytime sleepiness, sharing with narcolepsy a short sleep latency and the presence of sleep-onset rapid eye movement periods during the Multiple Sleep Latency Test. Since narcolepsy is characterized by a dysfunction of the hypothalamic hypocretin system, we investigated whether patients with myotonic dystrophy type 1 with excessive daytime sleepiness have abnormalities in the hypocretin system. DESIGN/PARTICIPANTS: Six patients with myotonic dystrophy type 1 complaining of excessive daytime sleepiness and 13 healthy controls without a sleep disorder were included. The patients with myotonic dystrophy type 1 were evaluated using clinical interviews, nocturnal polysomnograms, and Multiple Sleep Latency Tests. All patients had a confirmed genetic diagnosis for DM1 and were HLA typed. Cerebrospinal fluid hypocretin-1 levels were measured using a direct radioimmunoassay in patients and controls. Setting: University hospital sleep laboratory. INTERVENTIONS: N/A. MEASUREMENT AND RESULTS: The mean sleep latency on Multiple Sleep Latency Tests was abnormal in all patients (< 5 minutes in 2, < or = 8 in 4) and 2 sleep-onset rapid eye movement periods were observed in 2 subjects. All patients were HLA-DQB1*0602 negative. Hypocretin-1 levels were significantly lower in patients versus controls (p < 0.001); 1 case with 2 sleep-onset rapid eye movement periods had hypocretin-1 levels in the range generally observed in narcolepsy (< 110 pg/mL). Three cases had intermediate levels (110-200 pg/mL). Hypocretin-1 levels did not correlate clinically with disease severity or duration or with subjective or objective sleepiness reports. CONCLUSIONS: A dysfunction of the hypothalamic hypocretin system may mediate sleepiness and abnormal Multiple Sleep Latency Test results in patients with myotonic dystrophy type 1.     

Invasive micropapillary carcinoma of the breast is associated with chromosome 8 abnormalities detected by comparative genomic hybridization

Invasive micropapillary carcinoma (IMC) of the breast is a rare variant of invasive ductal carcinoma (IDC) characterized by unique histology and an extremely high incidence of lymph node metastases (approximately 95%). Comparative genomic hybridization (CGH) was used to characterize DNA extracted from 16 archival IMC cases to identify clonal genetic changes associated with this unique and highly metastatic cancer subtype. The average number of chromosomal alterations per IMC tumor was 7.4 +/-2.9 (3.4 gains and 3.9 losses), fewer than the number that we have observed in IDCs not otherwise specified (9.5 +/-6.6), IDCs with erbB-2 gene amplification (12.6 +/-5.9), and invasive lobular carcinomas (8.2 +/-5.5). The mean number of changes in IMC was significantly higher than we have observed in the rarely metastasizing tubular subtype of IDC (3.9 +/-2.3, P = 0.001), but less than the more aggressive subset of erbB-2-amplified IDC (P = 0.02). Remarkably, 100% of IMCs demonstrated loss involving the short arm of chromosome 8 (8p). Six cases showed loss of the entire 8p arm, whereas in 10 cases the loss was limited to the distal portion (8p21-pter) with localized gain of proximal 8p (8p11-p12). A reciprocal gain of 8q was detected in 14 cases (88%). Other common alterations included loss of 17p in 50% of tumors and loss of 16q in 50% of IMC cases. Gains of 17q (38%), 1q (31%), and 16p (25%) were also commonly detected. In comparison, IDCs (not otherwise specified), IDCs of the tubular subtype, and invasive lobular carcinomas showed only modest 8p loss (33%, 28%, and 13%, respectively). This region of chromosome 8 may contain 1 or more genes whose loss leads to this particular histology and/or the lymphotrophic phenotype associated with this histopathologic pattern.     

Comparison of chlorhexidine and tincture of iodine for skin antisepsis in preparation for blood sample collection

Rates of contamination of blood cultures obtained when skin was prepared with iodine tincture versus chlorhexidine were compared. For iodine tincture, the contamination rate was 2.7%; for chlorhexidine, it was 3.1%. The 0.41% difference is not statistically significant. Chlorhexidine has comparable effectiveness and is safer, cheaper, and preferred by staff, so it is an alternative to iodine tincture.     

Depletion of peripheral blood T lymphocytes and NK cells during the course of ebola hemorrhagic Fever in cynomolgus macaques

During the course of an experimentally induced Ebola virus (EBOVA) infection of cynomolgus macaques, peripheral blood mononuclear cells were isolated and characterized by multi-color flow cytometry. Both CD4+ and CD8+ lymphocyte counts decreased 60-70% during the first 4 days after infection. Among CD8+ lymphocytes, this decline was greatest among the CD8(lo) population, which was composed mostly of CD3- CD16+ NK cells. In contrast, the number of CD20+ B lymphocytes in the blood did not significantly change during the course of the infection. Phenotypic analysis of T lymphocyte subsets by flow cytometry failed to show evidence of a robust immune response to the infection. Apoptosis could be detected as early as day 2 postinfection among the CD8+ and CD16+ subsets of lymphocytes. Increased expression of CD95 (Fas) suggests that apoptosis may be induced via signaling through the Fas/Fas-L cascade. In contrast, the number of HLA-DR+ cells increased tenfold in the blood during the course of infection. These data suggest that EBOV may block dendritic cell maturation after infection, thereby inhibiting activation of lymphocytes and eliminating those subsets that are most likely to be capable of mounting an effective response to the virus.     

Endocarditis with ruptured cerebral aneurysm caused by Cardiobacterium valvarum sp. nov

A fastidious gram-negative bacterium was isolated from the blood of a 37-year-old man who had insidious endocarditis with a sudden rupture of a cerebral aneurysm. Characterization of the organism through phylogenetic and phenotypic analyses revealed a novel species of Cardiobacterium, for which the name Cardiobacterium valvarum sp. nov. is proposed. C. valvarum will supplement the current sole species Cardiobacterium hominis, a known cause of endocarditis. Surgeries and antibiotic treatment cured the patient's infection and associated complications. During cardiac surgery, a congenital bicuspid aortic valve was found to be the predisposing factor for his endocarditis.     

Translocation (X;20) involving the inactive X chromosome in a patient with myeloproliferative disorder

We report a patient with an unclassifiable myeloproliferative disorder and the rare t(X;20)(q13;q13.3) as the sole cytogenetic abnormality. The breakpoint on Xq is consistent with other reports of translocations involving the X chromosome with breakpoints that cluster to Xq13 and association with myeloid disorders. Late replication studies demonstrated the inactive X chromosome was involved in this translocation. The critical event in patients with myeloproliferative disease and deletion of 20q appears to be the loss of tumor suppressor genes. This may also be the mechanism in this patient with a potential cryptic deletion associated with the translocation. Alternatively, spreading of X inactivation into the derivative chromosome 20 provides a second mechanism for the loss of function of tumor suppressor genes on 20q. The finding in this patient of t(X;20) together with three others reported in the literature indicates that this may represent a primary non-random abnormality associated with myeloid malignancy, which may take on clinical significance with the accumulation of more cases.