New products related to kinamycin from Streptomyces murayamaensis. I. Taxonomy, production, isolation and biological properties

Six new products of Streptomyces murayamaensis sp. nov. Hata et Ohtani, the producer of the kinamycins, were isolated by silica gel column chromatography. The antibacterial activities of the new products, as well as that of dehydrorabelomycin and murayaquinone, previously isolated products of the same organism, were compared to the kinamycins. Three of the products had antibacterial activities similar to the kinamycins, while two others had activity only against Gram-positive bacteria. Dehydrorabelomycin and one other metabolite had no detectable antibacterial activity. The organism was found to be capable of aerial mycelium formation, with sporophores branched at regular intervals bearing square-ended spores with smooth surfaces. The culture contains L,L-diaminopimelic acid in the cell wall (Type I), is highly resistant to lysozyme, and lecithinase- and melanin-positive, suggesting a relationship with the genus Streptoverticillium and the lavendulae group of the genus Streptomyces.     

Partial prevention of procarbazine induced germinal cell aplasia in rats by sequential GnRH antagonist and testosterone administration

The present study examined the feasibility of using a combination of gonadotropin releasing hormone antagonist (GnRH-A) and testosterone in the prevention of procarbazine induced germinal aplasia. Daily injections of GnRH-A or vehicle were given to adult male rats for 21 days prior to procarbazine (PCB) administration and continued until 2 days after the second of two doses of procarbazine (200 mg/kg i.p.) given 1 week apart. One group of rats receiving GnRH-A and PCB was given s.c. two 5-cm testosterone capsule (TC) implants (inside diameter, 3.5 mm) immediately following the second dose of PCB. Eight weeks after the last PCB treatment, more than 99% of the seminiferous tubular cross-sections of rats receiving PCB alone were devoid of spermatogenic activity. Spermatogenesis in PCB injected animals receiving GnRH-A pretreatment alone was abortive but was partially preserved when exogenous testosterone was given following PCB administration. At 16 weeks, spermatogenesis was absent in all PCB treated animals and was only observed in less than 1% of the tubular cross-sections of the PCB treated rats receiving GnRH-A pretreatment alone. On the other hand, active spermatogenesis was noted in 68% of the tubular cross-sections, and complete spermatogenesis was noted in four of the five PCB treated rats receiving both GnRH-A pretreatment and subsequent TC implantation. At the time of sacrifice, testicular testosterone concentrations in animals receiving TC implants were below 10% of normal levels, while both serum and testicular testosterone content were increased in PCB treated animals with or without GnRH-A pretreatment. Concomitantly, testicular androgen binding protein content remained suppressed and serum androgen binding protein was elevated, indicating a prolonged defect in Sertoli cell function. These lesions were prevented by GnRH-A pretreatment. The present study demonstrates that GnRH-A pretreatment and subsequent TC implantation resulted in restoration of complete spermatogenesis in adult male rats given a 400-mg/kg cumulative dose of PCB. It is postulated that GnRH-A may ameliorate PCB induced Sertoli cell dysfunction and/or stimulate the number of spermatogonia to provide more proliferating cells ready for repopulation of the germinal epithelium following PCB injury. The differentiation of these spermatogonia was further supported by exogenous testosterone through certain unknown local mechanisms, resulting in the completion of spermatogenesis.     

Simultaneous repair of severe pectus excavatum and aortic valve replacement following previous open-heart surgery

A 60-year-old man with a severe degree of pectus excavatum and previous coronary artery surgery required aortic valve replacement. At operation the sternal wires were found to be densely adherent to the aortic wall. We describe the surgical technique, which was carried out uneventfully.     

Predictability of splenic salvage by computed tomography

The recognition of overwhelming post-splenectomy infection (OPSI) has led to greater efforts to conserve splenic tissue in patients sustaining blunt torso trauma. Nonoperative management of splenic trauma has emerged as a means to enhance splenic salvage yet criteria to assure the safety of such an approach remain ill defined and controversial. Since severity of injury directly influences outcome, a need exists for identification of splenic injuries that require early operation and repair or removal. Using our recently reported classification of splenic trauma, 46 patients with blunt splenic trauma were evaluated preoperatively with computed tomography (CT). Injuries were graded I through IV and were described as capsular or subcapsular disruptions without parenchymal injury (four); capsular and parenchymal injuries not involving the major vessels or hilum (24); injuries involving major vessels and/or the hilum (17); and fragmentation/devascularizing injuries (one). Additional modifiers were added for associated intra-abdominal and/or extra-abdominal injuries. Sixteen patients had their splenic injuries managed nonoperatively and the remainder underwent operation for the splenic injury or associated injuries. The CT classification was confirmed in all patients and we believe early operation optimized splenic salvage. We conclude that: 1) CT is an accurate technique to determine the extent of splenic injury; 2) CT classification of splenic trauma has a high correlation with anatomic findings and need for operation; 3) early operation in patients with severe class II and all class III injuries affords optimal conditions for splenic salvage; and 4) early definitive management of splenic trauma significantly reduces late splenectomy and shortens hospitalization.     

Expression of the antigenic determinant recognized by the monoclonal antibody 44-3A6 on select human adenocarcinomas and normal human tissues

The IgG1 monoclonal antibody, 44-3A6, was raised against the human lung adenocarcinoma cell line, A549. It has been shown to react with a 40,000 MW protein found on the cell surface, which is preserved in formalin-fixed paraffin-embedded tissues. A recent study of pulmonary carcinomas utilizing immunohistochemical methods showed exclusive binding to lung adenocarcinomas, subsets of neuroendocrine tumors, some carcinoids and a subset of large cell carcinomas. Reactivity was not seen in squamous cell carcinomas and small cell neuroendocrine carcinomas. In addition, melanomas, sarcomas and hematologic malignancies do not express this antigen. We now report on the reactivity pattern of 44-3A6 in adenocarcinomas of nonpulmonary primary sites and in normal adults organs. Strong diffuse staining of neoplastic cells in adenocarcinomas of the stomach, colon, pancreas, gallbladder and breast was noted. Adenocarcinomas arising in the endometrium, ovary, kidney, prostate, thyroid and liver were either negative or showed weak and/or focal reactivity. Strong staining patterns were even noted in adenocarcinomas which had an 'undifferentiated' component; i.e., lacking well-defined glandular elements. Immunoreactivity was noted in epithelial cells in several tissues from which these adenocarcinomas arose including the bronchial tract, stomach, small intestine, pancreas and colon, whereas epithelial cells from the endometrium, kidney, ovary, prostate and thyroid were negative or showed diffuse weak immunoreactivity. Our finding indicate that monoclonal antibody 44-3A6 recognizes an epithelial antigen on subsets of normal as well as transformed glandular epithelia. The differential pattern of expression of its target antigen probably reflects differences in tumor genesis and/or differentiation.     

石南藤、山蒟活性成分的分离和结构鉴定

已报道自山蒟及石南藤中分得海风藤酮(Ⅰ),denudatin B(Ⅱ),N-isobutyl-deca-trans-2-trans-4-dienamide(Ⅲ),本文继续报道自山蒟中分得一新木脂素,命名为山蒟素D(Ⅳ),X-衍射晶体结构测定为外消旋光学异构体。自石南藤分得Ⅳ的同系物,为新结构、命名为南藤素(Ⅴ),以及山蒟素C(Ⅵ),galgravin(Ⅶ),二氢毕拨明宁碱(Ⅷ)及巴豆环氧素(Ⅸ)。以上化合物皆首次自山蒟及石南藤中分得。以血小板活化因子(PAF)引起的血小板凝集实验测定活性,除Ⅲ,Ⅳ,Ⅶ,Ⅸ外皆有抑制活性。     

Magnetic resonance spectroscopy in childhood AIDS encephalopathy

Twenty-five children with acquired immunodeficiency syndrome (AIDS) underwent cranial magnetic resonance imaging and proton magnetic resonance spectroscopy. Patients were divided into 2 groups based on clinical parameters: encephalopathy and nonencephalopathy. N-acetyl aspartate/creatine ratios were compared between the 2 groups and to control data. Spectra were obtained for 2 volumes of interest: the basal ganglia region and the white matter. The mean basal ganglia region ratio for the AIDS encephalopathy patients (n = 8) was 1.12 and the ratio for the AIDS nonencephalopathy patients (n = 17) was 1.48. The ratio for the 9 controls was 1.57. The encephalopathy group had a significantly lower ratio than both the control (P < .001) and the AIDS nonencephalopathy group (P < .002). The mean white matter ratio for the encephalopathy group (n = 8) was 1.47 and for the AIDS nonencephalopathy group (n = 13) was 1.82 with a control (n = 6) ratio of 1.82. The encephalopathy patients had a lower white matter ratio than the nonencephalopathy (P < .05) patients but the ratio was not different than controls (P < .11). It is concluded that N-acetyl aspartate/creatine ratios are reduced in childhood AIDS encephalopathy and proton magnetic resonance spectroscopy may be helpful in defining brain human immunodeficiency virus-1 infection. However, further longitudinal studies are necessary to determine the sensitivity and specificity of this technique.     

Encephalitis caused by a Lyssavirus in fruit bats in Australia.

This report describes the first pathologic and immunohistochemical recognition in Australia of a rabies-like disease in a native mammal, a fruit bat, the black flying fox (Pteropus alecto). A virus with close serologic and genetic relationships to members of the Lyssavirus genus of the family Rhabdoviridae was isolated in mice from the tissue homogenates of a sick juvenile animal.     

ACCELERATED PAPER: Cloning, genetic mapping and expression studies of the rat Brca1 gene

The breast cancer gene BRCA1 has previously been cloned fromboth human and mouse. We cloned a fragment of the rat Brca1homologue in order to map it and explore its biological function.Partial cDNA fragments of the rat Brca1 homologue were isolatedby RT-PCR. Sequence analysis revealed that the RING-finger domainis well conserved among rat, mouse and human. Rat Brcal mRNAwas expressed in most tissues studied with the highest levelin testis, consistent with studies in human and mouse. Next,intron 6-containing DNA fragments were amplified by PCR fromWKY and WF strains. The splicing sites between exon 6 and exon7 are conserved between rat and human. Partial sequencing ofthe rat Brca1 intron 6 revealed a polymorphism of a pentanucleotideTTTTG repeat between the WKY and WF strains. With this intragenicmicrosatellite marker, we were able to map precisely the ratBrcal gene to chromosome 10 using a genetic linkage study of(WKYxWF)F1xWF baccross rats. Brca 1 cosegregates with markerBAND3A, and is flanked by R5123 and R5842. Using this polymorphicmarker, we also investigated the loss of heterozygosity (LOH)of the Brcal microsatellite marker in carcinogen- or radiation-inducedmammary carcinomas in (WFxF344)F1 female rats. No LOH or somaticmicrosatellite instability was detected in 18 DMBA-induced tumorsstudied. Only one LOH of the F344 allele was observed in 26radiation-induced tumors tested. Ribon-uclease protection assaysdemonstrated that Brca1 mRNA levels are similar in normal ratmammary glands and mammary carcinomas of various etiologies,including those induced by DMBA, NMU, activated-neu and activated-rasoncogenes.     

An immunohistochemical analysis of ras oncogene expression in epithelial neoplasms of the colon

Colonic epithelial tumors (101) including villoglandular adenomas, carcinomas in situ, adenocarcinomas, and neuroendocrine (NE) carcinomas were studied immunohistochemically with monoclonal antibodies (MoAb) RAP-5 and RAS-10 recognizing altered and unaltered ras oncogene products. In addition, 20 samples from multiple polyposis including adenomas with and without dysplasia, carcinomas in situ, and invasive carcinomas were studied. Using immunostaining techniques, normal mucosa was weakly stained, whereas the mucosa in the vicinity of tumors or inflammation showed enhanced staining. More tumors stained intensely with MoAb RAP-5 than with MoAb RAS-10. With MoAb RAP-5, most benign and malignant tumors showed enhanced staining. No significant differences in staining were noted in relation to superficial versus deeply invasive carcinomas or clinical staging. Immunostaining was also noted in some metastases. No significant differences in enhanced staining were found in carcinomas. Interestingly, the most extensive and enhanced immunostaining was noted in the villoglandular adenomas, dysplastic adenomas, and carcinomas in situ. The authors conclude that (1) ras protein expression is detectable in most benign, borderline, and malignant epithelial tumors of the colon as determined with MoAb RAP-5 and RAS-10, whereas enhanced expression is more often detected with RAP-5; (2) enhanced ras product expression in colon carcinomas does not seem to correlate with advanced tumor stages or with exocrine, NE, or phenotypically mixed tumors; and (3) the finding of the most intensely enhanced ras products expression in villoglandular polyps and carcinomas in situ suggests a possibly significant role for the oncogene in the early phases of transformation.