Not everything acid fast is Mycobacterium tuberculosis--a case report.

The Ziehl-Neelsen (ZN) stain is important in identifying organisms that are acid fast, principally Mycobacterium tuberculosis. However, decolorisation with a weaker acid concentration (for example 1% hydrochloric acid), often used in ZN staining in histology, can result in a wider variety of organisms appearing acid fast and can be a cause of misidentification. To illustrate this point, a patient is described with pulmonary nocardiosis who was misdiagnosed as having tuberculous empyema on pleural biopsy.     

Competitive binding to a charged leucine motif represses transformation by a papillomavirus E6 oncoprotein

E6 oncoproteins from HPV-16 and bovine papillomavirus type 1 (BPV-1) bind to similar leucine-rich peptides termed charged leucine motifs found on the cellular focal adhesion protein paxillin and the E3 ubiquitin ligase E6AP. BPV-1 E6 (BE6) mutants that do not bind to paxillin are defective at inducing cellular transformation. It is possible, however, that BE6 mutants that do not bind paxillin are defective for transformation for an unrelated reason than the ability to bind to charged leucine motifs. To address the role of BE6 interaction with charged leucine motifs, we fused a BE6-binding charged leucine motif to the amino terminus of BE6, thereby creating an autoinhibitory binding domain. We found that the fusion protein failed to bind to paxillin or transform murine C127 cells. Mutation of the amino terminal binding motif in the fusion protein restored both interaction with paxillin and transformation. This demonstrates that BE6 transformation requires binding to charged leucine motifs on particular cellular proteins and that transformation by papillomavirus oncoproteins can be repressed by competitive interactions with charged leucine motifs.     

Heterogeneity of monoclonal antibody-reactive epitopes on mycobacterial 30-kilodalton-region proteins and the secreted antigen 85 complex and demonstration of antigen 85B on the Mycobacterium leprae cell wall surface.

Proteins of the antigen 85 complex in the 30-kDa region secreted by live mycobacteria are important in the immune response against mycobacterial infections and may play an important biological role in the host-parasite interaction. In the present study, we have characterized epitopes of the 30-kDa-region proteins and the antigen 85 complex by using a panel of 13 monoclonal antibodies (MAbs) reacting with these antigens, 6 of which have not been described before. By using five previously characterized related secreted proteins of Mycobacterium tuberculosis, MPT44 (85A), MPT59 (85B), MPT45 (85C), MPT51 (27 kDa), and MPT64 (26 kDa), we have identified at least 10 different MAb-reactive epitopes on the proteins of the antigen 85 complex. A heterogeneous distribution of epitopes was observed within the components of the antigen 85 complex. Two distinct epitopes specific for antigen 85B and two other epitopes restricted to the 85A and 85B components were recognized. Two of them were shared with a previously unidentified 27-kDa protein present in M. tuberculosis culture fluid from which all MPT proteins were derived. The rest of the MAb-reactive epitopes were found to be present mostly in antigens 85A and 85B and to a lesser extent in antigen 85C. None of these MAbs recognized component 85C alone nor did they bind to the related MPT51 and MPT64 proteins. Interestingly, most of the MAbs reacted with purified native proteins of the antigen 85 complex but not to them in their denatured forms. In contrast, reactivity of the MAbs with the cytosol fraction of M. tuberculosis in immunoblotting revealed that they bound to a closely related cytosolic 30-kDa protein(s) even when they were denatured. Heterogeneity of these MAb-reactive epitopes of the antigen 85 complex was further evident as they were found to be distributed in various patterns among 19 different mycobacterial species. By using fusion proteins of the Mycobacterium leprae 30/31-kDa antigen 85 complex, we have localized at least six different epitopes within amino acid residues 55 to 266 of the M. leprae antigen 85 complex. Finally, by immunohistochemical analysis, we have demonstrated the in situ expression of one of the novel MAb-reactive epitopes specific for antigen 85B on the cell wall surface of M. leprae within macrophages in lepromatous leprosy lesions and thus provide direct evidence for the presence of the B component of the antigen 85 complex on the surface of intact M. leprae.     

Mammalian sex chromosomes III. Activity of pseudoautosomal steroid sulfatase enzyme during spermatogenesis inMus musculus

Parallel to the inactivation of the X chromosome in somatic cells of female, the male X in mammals is rendered inactive during spermatogenesis. Pseudoautosomal genes, those present on the X-Y meiotically pairable region of male, escape inactivation in female soma. It is suggested, but not demonstrated, that they may also be refractory to the inactivation signal in male germ cells. We have assayed activity of the enzyme steroid sulfatase, product of a pseudoautosomal gene, in testicular cells of the mouse and shown its presence in premeiotic, meiotic (pachytene), and postmeiotic (spermatid) cell types. It appears that, as in females, pseudoautosomal genes may escape inactivation in male germ cells also.     

Human papillomavirus DNA in urine samples of women with or without cervical cancer and their male partners compared with simultaneously collected cervical/penile smear or biopsy specimens.

Infection of specific types of high-risk human papillomaviruses (HPVs) causes cervical cancer in women. Conventional test for genital HPV infection requires collection of scraped cervical cells or biopsy specimens, which involves invasive procedures. Utility of non-invasive urine sampling for detection of HPV in women and their male sexual partners is controversial. The validation of this urine-based HPV DNA test is of immense value not only in screening large population and children but also for HPV vaccine monitoring in adolescents. We examined the frequency of high risk HPV types 16 and 18 in simultaneously collected urine samples and cervical scrapes or biopsy specimens from women with cervical cancer and their single lifetime male sexual partners in order to validate the utility of urine sampling as a reliable non-invasive method for detection of genital HPV infection. Thirty women with invasive cervical cancer and their husbands along with 30 age-matched normal healthy women including their husbands were recruited for the study. Cervical biopsies/scrapes from women subjects and penile scrapes from their husbands and urine samples from all of them were collected before taking biopsy or scrapes. HPV-L1 consensus primer as well as high-risk HPV (HPV 16 and 18) type-specific oligo-primers were used for PCR detection of HPV DNA. The total frequency of HPV in women with cervical cancer was found to be 83% (25/30) while it was only 67% (20/30) in their male partners but there was virtually no difference in results between urine and scrape or tissue biopsy either in women or their male partners. Although healthy women and their husbands showed similar frequency of HPV infection both in urine and scrape samples, there was a significant difference (p=0.05) in the prevalence of high risk HPV type 16 in women with cervical cancer (70%) and their male partners (30%). Similar was the trend between control women and their male partners. The results also showed a very high prevalence of HPV type 16 among Indian women with cervical cancer while its frequency was significantly low in their single lifetime male partners. The case by case matching of HPV positivity and negativity between urine and cervical/penile scrapes or biopsies obtained from women and their male partners demonstrated that the non-invasive urine sampling can be reliably used for screening genital HPV infection in both men and women.     

Missense mutation in a von Willebrand factor type A domain of the alpha 3(VI) collagen gene (COL6A3) in a family with Bethlem myopathy

The Bethlem myopathy is a rare autosomal dominant proximal myopathy characterized by early childhood onset and joint contractures. Evidence for linkage and genetic heterogeneity has been established, with the majority of families linked to 21q22.3 and one large family linked to 2q37, implicating the three type VI collagen subunit genes, COL6A1 (chromosome 21), COL6A2 (chromosome 21) and COL6A3 (chromosome 2) as candidate genes. Mutations of the invariant glycine residues in the triple-helical domain-coding region of COL6A1 and COL6A2 have been reported previously in the chromosome 21-linked families. We report here the identification of a G-->A mutation in the N-terminal globular domain-coding region of COL6A3 in a large American pedigree (19 affected, 12 unaffected), leading to the substitution of glycine by glutamic acid in the N2 motif, which is homologous to the type A domains of the von Willebrand factor. This mutation segregated to all affected family members, to no unaffected family members, and was not identified in 338 unrelated Caucasian control chromosomes. Thus mutations in either the triple-helical domain or the globular domain of type VI collagen appear to cause Bethlem myopathy.      

An allergic reaction following intrauterine insemination

Intrauterine insemination is a common procedure used for the treatment of different causes of infertility. Adverse reactions associated with this procedure are very rare and usually the procedure is well tolerated by the patient. We report a case of an allergic reaction after intrauterine insemination. The patient developed fever, difficulty breathing and wheezing in both lung fields. Although a low concentration of penicillin in the medium was used, it caused a significant allergic reaction. When intrauterine insemination was performed in subsequent cycles with an antibiotic-free medium, no allergic reaction occurred, and the procedure was well tolerated by the patient. A careful allergy history is essential in patients pursuing infertility treatment where antibiotics are utilized. Patients who are known to be allergic to penicillin should have semen prepared by an antibiotic-free medium.      

Chromatin interactions in differentiating keratinocytes reveal novel atopic dermatitis– and psoriasis-associated genes

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A 3 year retrospective review of intrauterine insemination, using cryopreserved donor spermatozoa and cycle monitoring by urinary or serum luteinizing hormone measurements

Insemination with donor spermatozoa is an integral part of infertility treatment. For the last 3 years in our unit, intrauterine insemination with donor spermatozoa (IUID) has been used in preference to vaginal insemination. In this retrospective study, patients were offered an initial course of five single intrauterine inseminations with cryopreserved donor spermatozoa and treatment was then reviewed. A total of 389 patients received 1465 inseminations. In all, 1119 cycles were monitored using luteinizing hormone serum analyses and 346 cycles using the urine home test kits. The clinical pregnancy rate per insemination for the cycles monitored by the serum assay was 18.0% (202/1119) compared with the urine cycles (13.7%, 46/346) (P <05). The pregnancy loss rate was not significantly different (14.4%, 29/202 and 21.7%, 10/46) (serum and urine cycles respectively). The viable clinical pregnancy rate was significantly higher (P <03) for the serum cycles than for the cycles using the urinary monitoring (15.5%, 173/1119 and 10.4%, 36/346 respectively). The cycles monitored by serum assay had a significantly higher cumulative viable clinical pregnancy rate (P <0001) of 70.2% after nine inseminations compared with the urine monitored cycles of 54.8%. The majority of patients opted for the serum cycles, with a minority self-selecting the urine cycles mainly for travelling convenience. The explanation for the significant differences between the viable clinical pregnancy rates per insemination and the cumulative viable clinical pregnancy rates may be due to the sensitivity of the urine home test kit or the patients' interpretation of the result.