Extensive transmission of Mycobacterium tuberculosis from a child

BACKGROUND AND METHODS: Young children rarely transmit tuberculosis. In July 1998, infectious tuberculosis was identified in a nine-year-old boy in North Dakota who was screened because extrapulmonary tuberculosis had been diagnosed in his female guardian. The child, who had come from the Republic of the Marshall Islands in 1996, had bilateral cavitary tuberculosis. Because he was the only known possible source for his female guardian's tuberculosis, an investigation of the child's contacts was undertaken. We identified family, school, day-care, and other social contacts and notified these people of their exposure. We asked the contacts to complete a questionnaire and performed tuberculin skin tests. RESULTS: Of the 276 contacts of the child whom we tested, 56 (20 percent) had a positive tuberculin skin test (induration of at least 10 mm), including 3 of the child's 4 household members, 16 of his 24 classroom contacts, 10 of 32 school-bus riders, and 9 of 61 day-care contacts. A total of 118 persons received preventive therapy, including 56 young children who were prescribed preventive therapy until skin tests performed at least 12 weeks after exposure were negative. The one additional case identified was in the twin brother of the nine-year-old patient. The twin was not considered infectious on the basis of a sputum smear that was negative on microscopical examination. CONCLUSIONS: This investigation showed that a young child can transmit Mycobacterium tuberculosis to a large number of contacts. Children with tuberculosis, especially cavitary or laryngeal tuberculosis, should be considered potentially infectious, and screening of their contacts for infection with M. tuberculosis or active tuberculosis may be required.     

Simple and efficient method for the detection of diethylenetriaminepentaacetic acid

Diethylenetriaminepentaacetic acid (DTPA) is a commonly used chelating agent. Its antiviral, antibacterial and immunomodulatory effects are well documented. DTPA forms a highly stable complex with lead (II) with an increased absorption coefficient and a bathochromic shift of the absorption maximum compared to pure DTPA. Based on this complex a high-performance liquid chromatographic method for the quantitative detection of DTPA in biological fluids was developed. A calibration curve was prepared and linearity was shown in the concentration range between 10 mg l(-1) and 1000 mg l(-1) DTPA. The recovery in water and in human plasma showed the method to be suitable for routine use.     

Trisomy 8 in primary esthesioneuroblastoma.

Esthesioneuroblastoma is a rare malignancy believed to be derived from neuroectodermal stem cells within the olfactory epithelium. We have obtained the karyotype of a primary esthesioneuroblastoma following brief (7-day) in vitro culture, and have determined that the only observable cytogenetic anomaly is the presence of an additional chromosome 8. Previously, the karyotypes of two cell lines established from metastatic esthesioneuroblastomas have been reported to contain the equivalent of three copies of chromosome 8, in addition to other chromosomal aberrations, including the reciprocal translocation, t(11;22)(q24;q12). Examination of the cytogenetic literature suggests that an extra copy of chromosome 8 is a common occurrence in undifferentiated small round cell tumors frequently observed to carry the t(11;22), including esthesioneuroblastoma, Ewing's sarcoma, peripheral neuroepithelioma, Askin's tumor, and rhabdomyosarcoma. These data, combined with our report of a small round cell tumor with the karyotype 47,XY, +8, indicate that trisomy 8 may be a common phenomenon in these tumors, and may also provide some sort of selective advantage to these tumor types.     

A murine TSPY

Sequences homologous to human and bovine TSPY were isolated from M. musculus testicular cDNA, and a nearly full-length gene was polymerase chain reaction (PCR) amplified from mouse genomic DNA. This gene is apparently non-functional. Contrary to the situation encountered in species along the primate and artiodactyl lineages, in which TSPY is moderately repetitive, murine Tspy appears to be single copy. Murine Tspy is located on Yp, i.e. in the same syntenic group as in man. Sequence comparisons of murine, human and bovine TSPY exons suggest that TSPY became non-functional during rodent evolution.     

Mikrokallusformationen der Spongiosa Ein bisher unterschätzter reparativer Mechanismus des Skelettsystems

Zusammenfassung Mikrokallusformationen lassen sich in nahezu allen Skelettabschnitten der Spongiosa nachweisen. Mikrokallus besteht aus Geflechtknochen, der sich an lokal überbelasteten Stellen in der Spongiosa bildet. Mit Hilfe einer speziellen Pr?parationstechnik wurden 26 skelettgesunde und 11 Wirbels?ulen von F?llen mit Osteoporose untersucht. Mikrokallusformationen finden sich bevorzugt bei Frauen ?lter als 45 Jahre in den unteren Wirbels?ulenabschnitten. Dabei hat die Mikroarchitektur der Spongiosa (TBPf) einen st?rkeren Einflu? auf die Anzahl der Mikrokalli, als individuelle Trabekelparameter (Tb.N, BV/TV und Tb.Th). Nur in 33 % der Formationen lassen sich Frakturspalten nachweisen. Mikrokallusformationen k?nnen nichtinvasive Knochenmassemessungen verf?lschen. Auch wenn Mikrokallusformationen Indikatoren für eine Instabilit?t der Spongiosa sind, tragen sie zur Knochenregeneration bei, und die Entstehung neuer Trabekel ist durch sie m?glich. Die Vorstellung, da? Osteoporose das Resultat einer verminderten Mikrokallusbildung ist, trifft nicht zu.      

alpha(v)beta(3) Integrin in central nervous system tumors

alpha(v)beta(3) Is an integrin specifically expressed in endothelial cells of newly forming blood vessels. Integrin-mediated angiogenesis is hypothesized to play a central role in the development and the progression of central nervous system neoplasms. Accordingly, it is considered a potential target for antiangiogenic therapy. In the current study, we compare the expression of alpha(v)beta(3) in ependymomas, oligodendrogliomas, pilocytic astrocytomas, medulloblastomas, and vestibular schwannomas (acoustic neuromas). Samples of 5 tumors of each of the 5 tumor types were harvested surgically and frozen. After the pathological diagnosis was confirmed, immunohistochemistry was performed using an anti- alpha(v)beta(3) monoclonal antibody (LM609). The expression of alpha(v)beta(3) was assessed using a 4-tiered (0-3) grading scheme reflecting the percentage of positively staining vessels. All vestibular schwannomas demonstrated strong (grade 3) alpha(v)beta(3) expression. The expression was uniformly prominent in Antoni B regions of the tumors. Of 5 ependymomas, 4 demonstrated uniformly strong alpha(v)beta(3). Oligodendrogliomas, medulloblastomas, and pilocytic astrocytomas demonstrated more variable alpha(v)beta(3). alpha(v)beta(3) may contribute significantly to angiogenesis in vestibular schwannomas and ependymomas. Despite the high vascular density of oligodendrogliomas, pilocytic astrocytomas, and medulloblastomas, these tumors had variable moderate alpha(v)beta(3) expression. This discrepancy suggests temporal and/or regional variability in the angiogenesis in these types of tumor. This study provides the first demonstration of alpha(v)beta(3) expression in vestibular schwannomas, medulloblastomas, and pilocytic astrocytomas.     

Stimulus specificity in the habituation of the startle response in the rat

A series of experiments evaluated whether the habituation of the startle response of the rat to tactile and auditory cues is stimulus specific. Experiment 1 showed stimulus specificity of a short-term habituation effect, whereby the startle to the second of a pair of stimuli was significantly less when the initial stimulus involved the same rather than the different modality. Experiments 2 and 3 focused on the more persistent decrement in startle that is a result of repeated stimulation, and demonstrated that such long-term habituation to the tactile and auditory stimuli contained a stimulus specific component in addition to a generalized component. The generalized habituation observed between the tactile and auditory stimuli in the three experiments may be due to an auditory accompaniment of the tactile stimulus employed. Discussion emphasized the utility of investigating habituation in a preparation with robust specificity.     

Psychological factors associated with the uptake of measles immunization: findings and implications for prevention

A cross-sectional study of 8204 children was performed to investigate the prevalence of immunization against measles, mumps and rubella and possible determinants of immunization uptake. The study was approached from a Lewinian perspective on preventive behaviour. Seventy-one questions referring to the guardian of the child, his or her partner, the household and the child, as well as to immunization-related experiences and situational topics were asked. Two psychological variables were studied: health locus of control and subjective relevance concerning measles. The immunization rate was 77.7 percent [95 percent confidence interval 76.8-78.6]. Multiple logistic regression yielded the following odds ratios for non- uptake of measles immunization: natural health orientation 8.74 [6.72-11.37]; advice of paediatrician 6.02 [4.67-7.75]; dangerousness of measles 2.00 [1.53-2.60]; marital status 1.87 [1.31-2.51]; assessed reliability of vaccination 1.57 [1.23-2.01]; smoking 1.55 [1.21-1.98]; and number of siblings 1.55 [1.21- 1.98]. Parents or guardians of immunized children were more internal and assessed measles as more relevant than those of non- immunized children.     

Characterization of the promastigote surface protease of Leishmania as a membrane-bound zinc endopeptidase

The effects of a variety of inhibitors suggested that the promastigote surface protease (PSP) of Leishmania might be a zinc metalloprotease. To investigate this possibility, we conducted atomic emission and absorption spectroscopic analyses, which show that PSP contains 1 atom of zinc per 63-kDa monomer. Further studies showed that the enzyme can be biosynthetically labeled with 65ZnCl2. The comparison of the amino acid sequence of Leishmania major PSP with nine other zinc metalloproteinases revealed significant similarity in the area of their zinc-binding sites. These data show clearly that the promastigote surface protease of Leishmania is a zinc metalloproteinase. Secondary structure analysis by circular dichroism spectroscopy indicates that PSP contains over 40% beta-strand and less than 20% alpha-helical structure. The molecular masses of amphiphilic PSP (152 kDa) and of hydrophilic PSP (142 kDa), determined by quantitative electron scattering, suggest that the purified enzyme occurs in solution, and presumably at the cell surface, as a non-covalent homodimer.