Spectrum of dolichospondylic dysplasia: two new patients with distinctive findings

Dolichospondylic dysplasia (DD) is a rare skeletal dysplasia primarily characterized by tall vertebral bodies and disproportionate short stature. Radiographic manifestations include tall vertebral bodies and gracile bones of the hands. Patients usually have eye and ear findings in addition to borderline mental retardation; however, tall vertebral bodies and slender tubular bones are also seen in the 3-M syndrome. Patients with the 3-M syndrome have a characteristic face with a triangular shape, frontal bossing, a flattened malar region, full eyebrows, a short nose with a bulbous tip, upturned nares, and full lips. We present two unrelated patients who share a distinct phenotype and have tall vertebral bodies, overtubulation of long bones, and short tubular bones of the hands and feet. We discuss the overlapping and distinguishing features between DD and the 3-M syndrome. Patient 1 was a 13-year-old female, and patient 2 was an unrelated adult female. These patients had normocephaly and short stature. They shared a common phenotype consisting of mild malar hypoplasia, a narrowed nasal body with a fleshy tip, full lips, and normal intelligence. In addition, they showed mild hand and foot abnormalities. These two patients lack many of the typical clinical features of both DD and the 3-M syndrome. They share a common phenotype and likely represent a distinct disorder. The spectrum of disorders with tall vertebral bodies as a key feature may include different entities that may be further defined with the characterization of the molecular defect(s).     

Factors associated with the provision of anti-smoking advice in general practice consultations.

Guidelines urge general practitioners (GPs) to discuss smoking with patients as frequently as possible. Using data collected before and after consultations, this study confirms that GPs are more likely to discuss smoking in the context of smoking-related problems. Encouraging GPs to make greater use of problem-orientated opportunities to discuss smoking may have more effect on rates of advice giving than urging them to advise all smokers.     

Antibody-mediated neutralization of pertussis toxin-induced mitogenicity of human peripheral blood mononuclear cells

Antibody-mediated neutralization of pertussis toxin-induced proliferation of human peripheral blood mononuclear cells (PBMC) was assessed using alamarBlue and compared with results from the Chinese hamster ovary (CHO) cell assay using sera from vaccinated adults and convalescent children. Neutralization values for the CHO assay were similar for vaccinated and convalescent subjects; however. the convalescent group had higher titers in the PBMC assay. Results for pertussis toxin neutralization with the CHO assay appear to be distinct from those with the PBMC assay.     

Role of inflammatory mediators in resistance and susceptibility to pneumococcal infection

Variations in the host response during pneumonia caused by Streptococcus pneumoniae in susceptible (CBA/Ca) and resistant (BALB/c) inbred mouse strains were investigated. Significant differences were detected in survival time, core body temperature, lung-associated and systemic bacterial loads, mast cell numbers, magnitude and location of cytokine production, lung disruption, and ability of isolated lung cells to release the cytokine tumor necrosis factor (TNF) alpha in vitro. Overall, the results indicate that the reduced capacity of CBA/Ca mice to induce rapid TNF activity within the airways following infection with S. pneumoniae may be a factor in their elevated susceptibility to pneumococcal pneumonia.     

Prevalence and correlates of HIV infection among young injection drug users in San Francisco

OBJECTIVE: We assessed the prevalence of HIV infection and associated risk behaviors among street-recruited young injection drug users (IDUs) in San Francisco. METHODS: In a cross-sectional study, 304 young (age <30 years) IDUs with a history of injecting in the previous 30 days were interviewed and tested for antibodies to HIV. Analyses assessing independent associations with HIV infection were limited to males only, due to the low number of infections in women. RESULTS: The prevalence of HIV infection was 5.3% overall but was highly stratified by gender and sexual preference (15.6% among homosexual/bisexual men vs. heterosexual men) and recruitment neighborhood (18% in the Polk Street area). Of 16 HIV infections, 14 (88%) were in males. Factors independently associated with HIV infection in males included sexual preference (homosexual/bisexual vs. heterosexual: adjusted odds ratio [AOR], 7.5; 95% confidence interval [CI], 1.5-36.6), recruitment neighborhood (Polk Street neighborhood vs. other neighborhoods: AOR, 4.8; 95% CI, 1.4-16.7), and duration of residence in San Francisco (>or=1 year vs. <1 year: AOR, 11.8; 95% CI, 1.4-95.8). CONCLUSIONS: The prevalence of HIV infection was highest among male IDUs who have sex with men. The strong associations between HIV infection and sexual orientation and HIV infection and recruitment locale suggest that risk may be attributable largely to sexual risk. In addition to successful prevention efforts aimed at reducing needle-associated risk, current intervention models aimed at young IDUs should target high-risk neighborhoods and emphasize sexual risk reduction measures, in particular among men who have sex with men.     

MCP-1-dependent signaling in CCR2(-/-) aortic smooth muscle cells

Monocyte chemoattractant protein-1 (MCP-1, CCL2) is a mediator of inflammation that has been implicated in the pathogenesis of a wide variety of human diseases. CCR2, a heterotrimeric G-coupled receptor, is the only known receptor that functions at physiologic concentrations of MCP-1. Despite the importance of CCR2 in mediating MCP-1 responses, several recent studies have suggested that there may be another functional MCP-1 receptor. Using arterial smooth muscle cells (SMC) from CCR2(-/-) mice, we demonstrate that MCP-1 induces tissue-factor activity at physiologic concentrations. The induction of tissue factor by MCP-1 is blocked by pertussis toxin and 1,2-bis(O-aminophenyl-ethane-ethan)-N,N,N',N'-tetraacetic acid-acetoxymethyl ester, suggesting that signal transduction through the alternative receptor is G(alphai)-coupled and dependent on mobilization of intracellular Ca(2+). MCP-1 induces a time- and concentration-dependent phosphorylation of the mitogen-activated protein kinases p42/44. The induction of tissue factor activity by MCP-1 is blocked by PD98059, an inhibitor of p42/44 activation, but not by SB203580, a selective p38 inhibitor. These data establish that SMC possess an alternative MCP-1 receptor that signals at concentrations of MCP-1 that are similar to those that activate CCR2. This alternative receptor may be important in mediating some of the effects of MCP-1 in atherosclerotic arteries and in other inflammatory processes.     

The 16189 variant of mitochondrial DNA occurs more frequently in C282Y homozygotes with haemochromatosis than those without iron loading

Background:Patients with hereditary haemochromatosis (HH) are usually homozygous for the C282Y mutation in the HFE gene. They have variable expression of iron overload and present with a variety of complications, including liver disease, diabetes, arthropathy, fatigue, and cardiomyopathy. The mitochondrial 16189 variant is associated with diabetes, dilated cardiomyopathy, and low body fat at birth, and might contribute to genetic predisposition in further multifactorial disorders. The objective of this study was to determine the frequency of the 16189 variant in a range of patients with haemochromatosis, who had mutations in the HFE gene.

Methods:Blood DNA was analysed for the presence of the 16189 variant in British, French, and Australian C282Y homozygotes and controls, with known iron status, and in birth cohorts.

Results:The frequency of the mitochondrial 16189 variant was found to be elevated in individuals with haemochromatosis who were homozygous for the C282Y allele, compared with population controls and with C282Y homozygotes who were asymptomatic (42/292 (14.4%); 102/1186 (8.6%) (p = 0.003); and 2/64 (3.1%) (p = 0.023), respectively).

Conclusions:Iron loading in C282Y homozygotes with HH was exacerbated by the presence of the mitochondrial 16189 variant.

     

Cerebro-osseous-digital syndrome: four new cases of a lethal skeletal dysplasia--distinct from Neu-Laxova Syndrome

Neu-Laxova Syndrome (NLS) is a severe disorder with intrauterine growth retardation, edema, and characteristic face (including microcephaly with receding forehead, protuberant eyes, a flattened nose, deformed ears, cleft palate, and micrognathia). Ichthyosis is often present. Limb anomalies include hypoplastic fingers and syndactyly of fingers and toes. Patients are usually stillborn or die shortly after birth. We report five unrelated patients--four with atypical NLS and one with typical NLS. All five patients were stillbirths. Clinically, the atypical NLS patients showed a large skull; rhizo-, meso-, and acromelia; and hypoplasia of the metacarpals and phalanges. The feet were similarly affected. Radiographically, the atypical patients showed interpediculate narrowing and hypoplastic vertebral bodies. The long bones were stick-like, showing diaphyseal widening that spared the metaphyses and was more pronounced in the lower extremities. The ilia had a half-moon configuration with widening of the sacrosciatic notches. The ischia were vertical and the pubic bone was absent. The typical NLS patient showed microcephaly, normal vertebral body, and long bone ossification, but a pelvic configuration similar to that of the atypical NLS patients. The common and distinguishing clinical and radiographic features are reviewed. Scott et al. [1981: Am J Med Genet 9:165-175] described two patients with NLS with radiographic and clinical findings similar to patients 1-4 reported here. Patients 1-4 of this report lack the typical findings of NLS and likely represent a distinct lethal skeletal dysplasia.     

Tumor necrosis factor-related apoptosis-inducing ligand can induce apoptosis in subsets of premalignant cells

During the transformation from a normal to a malignant cell, several mutations are required to bypass the pathways responsible for controlling proliferation. Premalignant cells have acquired some, but not all of these mutations and consequently have not yet attained a malignant phenotype characterized by tumor formation in vivo. Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) can induce apoptosis in malignant cells while sparing normal ones and is currently being considered as adjuvant therapy for various human malignancies. Whether TRAIL is effective in inducing apoptosis in premalignant cells is unclear, however. We studied the effect of TRAIL on two human premalignant cell lines the SV7tert and HA1E cells. Both cell lines had been immortalized by the addition of simian virus 40 large T antigen and the telomerase subunit hTERT, but had not been transformed into malignant cells. TRAIL initiated apoptosis by activating both the mitochondrial-independent and -dependent apoptotic pathways in both cell lines at relatively low doses whereas it had no effect on normal human pulmonary artery smooth muscle cells even at high doses. These results suggest that TRAIL can induce apoptosis in premalignant cells and suggests a novel therapy for the treatment of premalignant lesions in vivo.     

Spontaneous Cytokine Production and Its Effect on Induced Production

Cytokines regulate cellular immune activity and are produced by a variety of cells, especially lymphocytes, monocytes, and macrophages. Multiparameter flow cytometry is often used to examine cell-specific cytokine production after in vitro phorbol 12-myristate 13-acetate and ionomycin induction, with brefeldin A or other agents added to inhibit protein secretion. Spontaneous ex vivo production reportedly rarely occurs. We examined the spontaneous production of interleukin 2 (IL-2), IL-4, IL-6, IL-8, IL-10, tumor necrosis factor alpha (TNF-α), and gamma interferon (IFN-γ) by peripheral-blood B lymphocytes, T cells, CD8⁻ T cells, CD8⁺ T cells, CD3⁻ CD16/56⁺ lymphocytes (natural killer [NK] cells), CD3⁺ CD16/56⁺ lymphocytes (natural T [NT] cells), and/or monocytes of 316 acutely ill hospitalized persons and 62 healthy adults in Malawi, Africa. We also evaluated the relationship between spontaneous and induced cytokine production. In patients, spontaneous TNF-α production occurred most frequently, followed in descending order by IFN-γ, IL-8, IL-4, IL-10, IL-6, and IL-2. Various cells of 60 patients spontaneously produced TNF-α; for 12 of these patients, TNF-α was the only cytokine produced spontaneously. Spontaneous cytokine production was most frequent in the immunoregulatory cells, NK and NT. For IL-2, IL-4, IL-6, IL-8, and IL-10, spontaneous cytokine production was associated with greater induced production. For TNF-α and IFN-γ, the relationships varied by cell type. For healthy adults, IL-6 was the cytokine most often produced spontaneously. Spontaneous cytokine production was not unusual in these acutely ill and healthy persons living in an area where human immunodeficiency virus, mycobacterial, malaria, and assorted parasitic infections are endemic. In such populations, spontaneous, as well as induced, cell-specific cytokine production should be measured and evaluated in relation to various disease states.