A human in vitro model system for investigating genome-wide host responses to SARS coronavirus infection

Background

Schistosoma mansoni and Plasmodium falciparum are common infections of school aged children in Kenya. They both cause enlargement of the spleen, but their relative contribution to the condition of splenomegaly remains unknown in areas where both infections are endemic. Here, we have investigated whether relatively high exposure to both infections has a clinically measurable effect on this condition.

Methods

96 children aged 6–16 years living along a ten kilometre stretch and within 4 km south of a river that is a source of both S. mansoni and malaria infections were examined clinically for splenomegaly along the mid clavicular line (MCL) and mid axillary line (MAL). The survey was conducted outside the malaria transmission season. The consistency of the organ was recorded as soft, firm or hard. Mapping of the locations of houses and the course of the river was undertaken. Egg counts were mapped at the household level, as were IgG3 responses to Plasmodium falciparum schizont antigen (anti-Pfs IgG3), in order to identify areas with relatively high exposure to both infections, either infection or neither infection. ANOVA was used to test for differences in egg counts, IgG3 levels and the magnitude of spleen enlargement between these areas.

Results

4 contiguous sectors were identified, one where anti-Pfs IgG3 responses and S. mansoni egg counts were both high, one where only anti-Pfs IgG3 responses were high, one where only egg counts were high, and one where both anti-Pfs IgG3 responses and egg counts were low. Spleen MAL and MCL values were significantly higher amongst children from the sector with highest IgG3 levels and highest egg counts but similar amongst children from elsewhere. Both egg counts and anti-Pfs IgG3 responses were significantly higher in children with MAL values >=4 cm. Hardening of spleens was associated with proximity of domicile to the river.

Conclusions

Micro-geographical variation in exposure to S. mansoni and malaria infections can be exploited to investigate the chronic impact of these two infections. These results provide firm evidence that relatively high exposure to both infections exacerbates splenomegaly even outside the malaria transmission season. Major implications include assessing the burden of infection in school age-children.     

Distant cutaneous metastasis of pleural malignant mesothelioma

We report a facial tumor that was proven to be a metastatic mesothelioma. The diagnosis was not established pre-mortem. The patient died shortly after the facial biopsy, and an autopsy revealed a large pleural-based mass which had the gross appearance typical of a mesothelioma. Electron microscopic examination of tissue from the pleural tumor was diagnostic for mesothelioma. The patient had extensive visceral metastatic disease. Inclusion of this entity in the differential diagnosis of certain cutaneous tumors is important, in part because this lesion may be confused with angiosarcoma, particularly when it occurs in the skin of the face or head in older patients.     

Genes for catecholamine biosynthesis: cloning by expression and identification of the cDNA for rat dopamine beta-hydroxylase.

mRNA for dopamine beta-hydroxylase [3,4-dihydroxyphenylethylamine, ascorbate:oxygen oxidoreductase (beta-hydroxylating), EC 1.14.17.1] has been partially purified from poly(A)+ mRNA isolated from a rat pheochromocytoma cell line. Shared antigenic determinants between tyrosine hydroxylase and dopamine beta-hydroxylase allowed us to obtain enriched fractions of dopamine beta-hydroxylase mRNA by immunoprecipitating translated mRNA products with tyrosine hydroxylase antisera. The enriched dopamine beta-hydroxylase mRNA was used to synthesize the corresponding cDNAs, which were then cloned in the Pst I site of pBR322. Recombinant colonies were characterized by an in situ colony immunoassay and hybrid-selected translation. In vitro translation of the mRNA selected from one recombinant clone produced a protein of 75,000 daltons that comigrated with authentic dopamine beta-hydroxylase. Partial proteolysis of both authentic dopamine beta-hydroxylase and the protein encoded by the recombinant clone produced identical peptide patterns.     

Mutational scanning of large genes by extensive PCR multiplexing and two-dimensional electrophoresis: application to the RB1 gene

With the rapid increase in the number of identified human disease genes, the development of accurate and cost-efficient mutation tests has become opportune. Here we present a combination of extensive PCR multiplexing and two-dimensional (2-D) DNA electrophoresis to screen for mutations in 26 exons of the retinoblastoma (RB1) tumor suppressor gene. In 2-D electrophoresis, fragments are separated according to size and base pair sequence in non-denaturing and denaturing gradient gels, respectively. All target fragments, designed to have optimal melting characteristics, were prepared in a two-step PCR (a 6-plex long-PCR pre- amplification and a subsequent 25-plex short-PCR) followed by heteroduplexing. The mixture of PCR amplicons was then subjected to 2-D electrophoresis under a single set of experimental conditions. With this design, 35 previously identified mutations in 18 different exons were detected in 33 bilateral retinoblastoma patients. These results suggest that 2-D electrophoresis in this format provides a generally applicable, practical and fast way to diagnose with high accuracy large genes for a broad spectrum of possible disease-causing mutations.      

Relationship between image quality and ultrasound exposure level in diagnostic US devices

Ultrasonographic B-mode images were obtained at various exposure levels with three real-time diagnostic scanners. Adult human and tissue-equivalent phantom images were compared in terms of diagnostic content and depth of penetration. For the exposure level settings used, spatial-peak pulse-average intensities ranged from approximately 10 to 500 W/cm2. At the 3.50-3.75-MHz nominal frequencies used in the study, images of the human abdomen showed little discernible change in quality with varying exposure levels. However, phantom tests confirmed that depth of penetration is a function of exposure level. The results suggest that a judicious use of exposure level and receiver gain controls can be a practical means for minimizing patient exposure to ultrasound without sacrifice of diagnostic effectiveness.     

男性不育症精浆中超氧化物歧化酶、锌、睾酮含量的研究

本文采用一种简便灵敏的改良邻苯三酚法测定了236例不育症患者和27例正常育龄男子精浆中铜锌超氧化物歧化酶(CuZn-SoD)含量,同时还测定了精浆锌(Zn)和睾酮(T)含量。结果表明:在不育症精浆中,CuZn-SOD、Zn、T与精子密度之间均有显著正相关(P<0.01);CuZn-SOD和Zn含量与精子活动度均有密切关系,含量高活动度也高(P<0.001);CuZn-SOD和Zn之间亦存在显著正相关(P<0.01). 在精子密度范围同60～100×10~6/ml时.不育组与生育组精浆中CuZn-SOD、Zn、T含量均无统计学差异(P<0.2).本究究提示.CuZn-SOD作为精浆保护因子,通过抑制类脂过氧化反应使精子免受损伤。精浆CuZn-SOD含量测定有可能作为衡量精液质量的新指标。应用SOD类制剂治疗男性不育症可能有裨益。