Monocrotaline-induced cardiopulmonary injury in rats. Modification by the neutrophil elastase inhibitor SC39026

Rats were killed after 6 weeks of continuous ingestion of the pneumotoxic alkaloid monocrotaline (2.2 mg/kg/day), the neutrophil elastase inhibitor SC39026 (60 mg/kg/day), or both. Pulmonary reactions were evaluated by light and electron microscopy. Lung endothelial function was monitored by angiotensin converting enzyme (ACE) activity, plasminogen activator (PLA) activity, and prostacyclin (PGI2) and thromboxane (TXA2) production. Lung hydroxyproline content was measured as an index of interstitial fibrosis. Cardiac right ventricular hypertrophy was determined by the right ventricle to the left ventricle plus septum weight ratio (RV/LV + S). Rats receiving SC39026 alone did not differ significantly from untreated control animals with respect to any of the quantitative endpoints, although rarefaction of Type I pneumocytes was observed in the electron micrographs of these animals. Monocrotaline-treated rats, in contrast, developed a significant increase in RV/LV + S, and exhibited pulmonary edema, inflammation, fibrosis, and muscularization and occlusive mural thickening of the pulmonary small arteries and arterioles. These monocrotaline-induced structural changes were accompanied by decreased lung ACE and PLA activities, and increased PGI2 and TXA2 production, and by an increase in lung hydroxyproline content. Cotreatment with SC39026 ameliorated the monocrotaline-induced pulmonary vascular wall thickening and the cardiac right ventricular hypertrophy. These data suggest that inappropriate neutrophil elastase activity contributes to monocrotaline pulmonary vasculopathy and hypertension. On the other hand, cotreatment with SC39026 had no significant effect on the severity of the monocrotaline-induced lung inflammatory reaction, the pulmonary endothelial dysfunction, or the increase in lung hydroxyproline content.     

Emergence and scattering of multiple neurofibromatosis (NF1)-related sequences during hominoid evolution suggest a process of pericentromeric interchromosomal transposition

Type 1 neurofibromatosis (NF1) gene encodes for a member of the GTPase activating protein family and is considered to be a tumor suppressor gene. Its very high rate of de novo mutation in humans led us to study a specific feature of this gene: the presence of numerous NF1-related sequences. According to our results, the human genome contains at least 11 NF1-related sequences, nine of which are scattered near centromeric sequences of seven different chromosomes. These NF1-related sequences, whose extent is quite varied according to loci, are unprocessed copies of the NF1 gene, and bear numerous mutations. A phylogenetic analysis of the six largest sequences indicates that they are all derived from a common ancestor, which would have appeared 22-33 million years ago, and was subsequently duplicated several times during hominoid evolution. The most recent duplication and interchromosomal transposition occurred in the last million years suggesting that the process could still be ongoing. Intriguing similarities between the evolution of alpha- satellite DNA and NF1-related sequences suggest the involvement of a common genetic mechanism for the generation and pericentric spreading of these NF1 partial copies.      

Isolated and combined effects of prolonged exposures to noise and whole-body vibration on hearing,vision and strain

Summary This study was carried out in order: (1) to examine the effects of isolated and combined prolonged exposures to noise and whole-body vibration on hearing, vision and subjectively experienced strain, and (2) to check the combined effects with repeated exposures. Six male subjects were exposed twice to noise (N) at 92 dBA, whole-body vibration (V) in the Z-axis at 4 Hz and 1.0 ms^–2 rms, and noise and vibration (NV) for 90 min with each condition. Temporary threshold shifts of hearing (TTS) and their integrals (ITTS) were measured at 4, 6, 10, and 12 kHz. Visual acuity was examined by means of a very sensitive test. Cross-modality matching (CMM) of the handgrip force was used to judge the subjectively experienced strain. NV induced a clear tendency of higher TTS and ITTS than N, with several significant differences most pronounced at 10 kHz. With repeated exposures, the effect of NV decreased, while the reactions to N and V remained unchanged. The individual reactions to NV differed. The influence of the duration of exposures on vision depended on the condition; N caused time-dependent changes, whereas V did not. CMM-data increased with the duration of the exposure during V and NV. N was generally judged to be more straining than V; NV caused higher strain than V during the first 30 min of exposure only. Correlations between different effects suggest certain links between them. Additionally, less motivation — daily obtained by a questionnaire — often correlated with higher ITTS during N and NV. The results also illustrate the combined effects on the individual susceptibility, repetition of exposure, the kind of response, and, possibly, the actual psychic state.Abbreviations CMM cross-modality matching - MVC maximum voluntary contraction force - N exposure condition: noise level 92dBA, no whole-body vibration - NV exposure condition: combined exposure to noise with a level of 92 dBA and wholebody vibration with 4 Hz, 1 ms^–2 rms - V exposure condition: whole-body vibration with 4 Hz, 1 ms^–2 rms - TTS temporary threshold shift - ITTS integral of temporary threshold shift - WBV whole-body vibration in the common sense This work was done in the Temporary International Research Team on Combined Effects of Noise and Vibration of the Council of Mutual Economic Assistance of the Socialist Countries. The authors gratefully acknowledge the help and assistance of L.-M. Brumm, Y. Bening, M. Godau, G. Weber, and R. Vizcaino.     

Changes in substance P concentration in rat plasma under different conditions of blood letting

The influence of various conditions at blood-letting on the concentration of SP in the plasma was investigated in male Wistar rats as background for following studies on effects of noxae. Narcotic substance (hexobarbital, ether), CO2-suffocation and the mechanical kinds of killing (cervical dislocation, occipital hit, decapitation) influence the SP concentration in different ways. It is assumed SP concentration in plasma after cervical dislocation to be the best corresponding value for physiological conditions.     

Intron and upstream sequences regulate expression of the Drosophila beta 3-tubulin gene in the visceral and somatic musculature, respectively.

The morphogenetic programs involved in the differentiation of internal organs, such as the muscle system, during Drosophila embryogenesis have remained largely obscure. beta 3-tubulin has proved to be a good marker for mesoderm development as this tubulin isotype is detectable soon after mesoderm formation and during the process of mesoderm differentiation. The beta 3-tubulin gene is expressed in the somatic and pharyngeal musculature, the dorsal vessel, and the visceral musculature. To learn more about the programs underlying mesodermal differentiation, we have started to dissect the regulatory elements of the beta 3-tubulin gene by means of P-element-mediated transformation experiments. We show that expression of the beta 3-tubulin gene in the somatic muscles, the pharyngeal muscles, and the dorsal vessel is mediated by far upstream sequences. We also demonstrate that the first intron of the beta 3-tubulin gene bears a tissue-specific enhancer element that is required for expression in the visceral muscles and that also functions efficiently when cloned downstream of an indicator gene. The separability of elements driving beta 3-tubulin expression in the somatic and visceral mesoderm facilitates the investigation of the different programs involved in regulating the early differentiation of this germ layer.     

Reference and target region modeling of [11C]-(R)-PK11195 brain studies.

PET with [(11)C]-(R)-PK11195 is currently the modality of choice for the in vivo imaging of microglial activation in the human brain. In this work we devised a supervised clustering procedure and a new quantification methodology capable of producing binding potential (BP) estimates quantitatively comparable with those derived from plasma input with robust quantitative implementation at the pixel level. METHODS: The new methodology uses predefined kinetic classes to extract a gray matter reference tissue without specific tracer binding and devoid of spurious signals (in particular, blood pool and muscle). Kinetic classes were derived from an historical database of 12 healthy control subjects and from 3 patients with Huntington's disease. BP estimates were obtained using rank-shaping exponential spectral analysis (RS-ESA) (both plasma and reference input) and the simplified reference tissue model (SRTM). Comparison between plasma- derived BPs and those produced with the new reference methodology was performed using 6 additional healthy control subjects. Reliability of the new methodology was performed on 4 test-retest studies of patients with Alzheimer's disease. RESULTS: The new algorithm selected reference voxels in gray matter tissue avoiding regions with specific binding located, in particular, in the venous and arterial circulation. Using the new reference, BP values obtained using a plasma input and a reference input were in excellent agreement and highly correlated (r = 0.811, P < 10(-5)) when calculated with RS-ESA and less so (r = 0.507, P < 0.005) when SRTM was used. In the production of parametric maps, SRTM was used with the new reference extraction, resulting in test-retest variability (10.6%; mean ICC = 0.878) that was superior to that obtained using the previous unsupervised clustering approach (mean ICC = 0.596). CONCLUSION: Reference region modeling combined with supervised reference tissue extraction produces a robust and reproducible quantitative assessment of [(11)C]-(R)-PK11195 studies in the human brain.     

Differentiation of vaccine strains and field isolates of pseudorabies (Aujeszky's disease) virus: Trypsin sensitivity and mouse virulence markers

Summary Five cloned virulent North American field isolates and 2 European vaccine strains of pseudorabies (PR) viruses were compared by their sensitivity to trypsin and their virulence for mice. Marked differences in trypsin sensitivity were detected between and among virulent and vaccine PR viruses. These differences were distinct enough to characterize a virus as either sensitive or resistant to trypsin. This test also differentiated 2 virulent viruses which were previously shown to be indistinguishable on the basis of their sensitivity to thermal inactivation. Mouse virulence was evaluated by comparing the mean times-to-death of mice infected with individual viruses. Three distinct levels of virulence were observed. The two vaccine viruses were differentiated from each other and from virulent virus. Mice infected with the vaccine viruses required 23 to 118 hours longer to die than mice which were infected with virulent virus. A significant difference of 5.6 hours (P < .005) was also detected between mice infected with 2 different field viruses. When viruses were described according to their marker profiles, 5 of 6 possible combinations were revealed. The 2 vaccine viruses could be described by separate profiles and virulent viruses could be described by 1 of 3 profiles.With 2 Figures     

Homozygosity mapping of achromatopsia to chromosome 2 using DNA pooling

Achromatopsia is an autosomal recessive disease of the retina, characterized clinically by an inability to distinguish colors, impaired visual acuity, nystagmus and photophobia. A genome-wide search for linkage was performed using an inbred Jewish kindred from Iran. To facilitate the genome-wide search, we utilized a DNA pooling strategy which takes advantage of the likelihood that the disease in this inbred kindred is inherited by all affected individuals from a common founder. Equal molar amounts of DNA from all affected individuals were pooled and used as the PCR template for short tandem repeat polymorphic markers (STRPs). Pooled DNA from unaffected members of the kindred was used as a control. A reduction in the number of alleles in the affected versus control pool was observed at several loci. Upon genotyping of individual family members, significant linkage was established between the disease phenotype and markers localized on chromosome 2. The highest LOD score observed was 5.4 (theta = 0). When four additional small unrelated families were genotyped, the combined peak LOD score was 8.2. Analysis of recombinant chromosomes revealed that the disease gene lies within a 30 cM interval which spans the centromere. Additional fine-mapping studies identified a region of homozygosity in all affected individuals, narrowing the region to 14 cM. A candidate gene for achromatopsia was excluded from this disease interval by radiation hybrid mapping. Linkage of achromatopsia to chromosome 2 is an essential first step in the identification of the disease-causing gene.      

Contribution to the differentiation of haemophilus-strains isolated from chickens. II: Serological examinations using the plate-agglutination test

A total of 31 field isolates, 23 of them belonging to the H. paragallinarum species were examined serologically by means of the rapid slide agglutination test (RSA-test). One H. paragallinarum strain of serotype A, one of serotype B, and one serologically unclassified strain from California were used as reference strains. In addition, one strain of H. parainfluenzae was 'included 'in these studies. On the basis of the results of the RSA-tests With rabbit antisera 2 distinct serotypes of H. paragallinarum were differentiated. Cross reactions were observed among the serotypes which could be eliminated by dilution and absorption of the antisera. Eight of 23 H. paragallinarum isolates belonged to serotype A and 13 to serotype B. Two isolates showed spontaneous agglutination in 0.85% saline. Seven of 8 other isolates of Haemophilus bacteria, representing a culturally and biochemically separate group, could be distinguished from H. paragallinarum strains without difficulty. One strain showed spontaneous agglutination. The other 7 isolates formed 4 distinct serotypes on the basis of the RSA-tests, of which 3 isolates belonged to serotype 1, 2 to serotype 2, and one each to serotypes 3 and 4. Weak cross reactions were observed among these serotypes. No strains isolated from chickens included in this study were serologically identical with the strain of H. parainfluenzae.