Inbred guinea pig model of intrauterine infection with cytomegalovirus.

Outbred guinea pigs have previously been utilized in an experimental model for the study of congenital infection with cytomegalovirus (CMV). Development of an inbred model of intrauterine CMV infection would allow analysis of the cells involved in CMV immunity, studies of transplacental CMV transfer, and investigation of the cellular immune factors that participate in intrauterine CMV infections. This study was therefore designed to assess the inbred guinea pig as a model for the study of congenital CMV infection. Intrauterine fetal and placental infection with CMV was demonstrated in inbred Strain 2 guinea pigs, and the maternal factors influencing transplacental transmission of CMV were evaluated. Infectious virus was recovered from placentas and offspring of mothers that experienced primary CMV infection during pregnancy, but not from placentas and offspring of mothers that were inoculated with CMV prior to pregnancy. However, histologic lesions consisting of focal necrosis and inflammation were seen in tissues of offspring from both groups of mothers. Inoculation of seronegative pregnant Strain 2 animals with low doses of virus (2.5 to 3.5 log10 TCID50) resulted in both placental and fetal CMV infection without significant maternal death. Infection of placentas and offspring occurred in utero regardless of the stage of pregnancy. In addition, infectious virus was detectable in fetal tissues at the time of maternal viremia but also later during the course of maternal infection, ie, 4 weeks after inoculation. These findings indicate that the inbred guinea pig model can be used to investigate the pathogenesis of intrauterine CMV infections.     

Proximal femur bone marrow blood perfusion indices are reduced in hypertensive rats: A dynamic contrast‐enhanced MRI study

Purpose:

To investigate the differences in proximal femoral bone marrow blood perfusion indices between hypertensive and normotensive rats using perfusion magnetic resonance imaging (MRI).

Materials and Methods:

Six‐month‐old male spontaneously hypertensive rats (SHR) and Wistar Kyoto rats (WKY) were used (12 of each). Dynamic contrast‐enhanced MRI of the right hip was performed after bolus injection of Gd‐DOTA administered through a tail vein cannula. In all, 800 images were acquired at 0.6 sec/image. Regions of interest (ROIs) were drawn comprising the medullary component of proximal femoral shaft and femoral head. MRI maximum enhancement (E^max) and enhancement slope (E^slope) were analyzed.

Results:

The E^max and E^slope of proximal femoral shaft and femoral head of SHR were significantly lower than those of WKY (E^max: 107.4 ± 18.2% vs. 130.6 ± 21.5%, P = 0.009, and 76.0 ± 12.5% vs. 97.9 ± 6.9%, P < 0.001, respectively; E^slope: 3.01 ± 0.63%/sec vs. 3.75 ± 0.74%/sec, P = 0.016, and 1.95 ± 0.33%/sec vs. 2.28 ± 0.28%/sec, P = 0.012, respectively). The E^max and E^slope of femoral head were significantly lower than those of proximal femoral shaft in both SHR and WKY (P < 0.001). In both SHR and WKY, proximal femoral shaft and femoral head had a rather different contrast enhancement pattern.

Conclusion:

Proximal femoral shaft and femoral head bone marrow blood perfusion indices were significantly lower in hypertensive rats than in normotensive rats. Femoral head bone marrow was less perfused than proximal femoral shaft in both rats. J. Magn. Reson. Imaging 2009. © 2009 Wiley‐Liss, Inc.     

A comparison of the original chronic respiratory questionnaire with a standardized version

BACKGROUND AND OBJECTIVES: The chronic respiratory questionnaire (CRQ), a widely used measure of health-related quality of life (HRQL) in patients with chronic airflow limitation, includes an individualized dyspnea domain (patients identify five important activities, and report the degree of dyspnea on a 7-point scale). Because the individualized domain is unwieldy in multicenter clinical trials, we developed a standardized version and tested its discriminative and evaluative properties. METHODS: We enrolled 51 patients who completed the standardized and individualized CRQ before starting a respiratory rehabilitation program, and again 3 months later. We calculated both cross-sectional and longitudinal correlations between the two versions and a number of other HRQL instruments, and tested the relative ability of the individualized and standardized versions of the CRQ to detect improvement with rehabilitation. RESULTS: The results of the individualized questions suggested greater dysfunction (lower scores) than did the standardized questions both at baseline (3.18 vs 3.92, p < 0.001) and follow-up (4.62 vs 4.84, p = 0.051). The standardized dyspnea domain showed superior discriminative validity. While both techniques detected important, statistically significant improvement with rehabilitation (individualized domain mean change, 1.44; 95% confidence interval [CI], 1.11 to 1.77 [p < 0.001]; standardized domain mean change, 0.92; 95% CI, 0.61 to 1.24 [p < 0.01]), the difference in effect was substantial and statistically significant (mean difference, 0.52; 95% CI, 0.22 to 0.82; p = 0.001). The two versions showed comparable longitudinal validity. CONCLUSIONS: A standardized version of the CRQ dyspnea domain improves the cross-sectional validity, maintains longitudinal validity, but reduces the responsiveness. By increasing sample size, investigators can use the more efficient standardized version of the CRQ without compromising validity.     

Diagnosis of nontuberculous mycobacterial infections

This section discusses the methods of laboratory diagnosis of nontuberculous mycobacteria (NTM) using conventional biochemical and nutritional requirements, acid-fast smear microscopy, high performance liquid chromatography (HPLC), antibiotic susceptibility testing, and newer genetic methods such as molecular probes, polymerase chain reaction restriction fragment length polymorphism analysis (PRA), and 16S rDNA sequence analysis. This article discusses how laboratory results are applied by clinicians, and some of the difficulties and controversies regarding the diagnosis of NTM disease after the laboratory work is complete.     

Granulocyte Transfusions in Patients with Chronic Granulomatous Disease Undergoing Hematopoietic Cell Transplantation or Gene Therapy

Journal of Clinical Immunology - Granulocyte transfusions are sometimes used as adjunctive therapy for the treatment of infection in patients with chronic granulomatous disease (CGD). However,...     

Attenuated virulence of a Burkholderia cepacia type III secretion mutant in a murine model of infection

Type III secretion systems are utilized by a number of gram-negative bacterial pathogens to deliver virulence-associated proteins into host cells. Using a PCR-based approach, we identified homologs of type III secretion genes in the gram-negative bacterium Burkholderia cepacia, an important pulmonary pathogen in immunocompromised patients and patients with cystic fibrosis. One of the genes, designated bscN, encodes a member of a family of ATP-binding proteins believed to generate energy driving virulence protein secretion. Genetic dissection of the regions flanking the bscN gene revealed a locus consisting of at least 10 open reading frames, predicted to encode products with significant homology to known type III secretion proteins in other bacteria. A defined null mutation was generated in the bscN gene, and the null strain and wild-type parent strain were examined by use of a murine model of B. cepacia infection. Quantitative bacteriological analysis of the lungs and spleens of infected C57BL/6 mice revealed that the bscN null strain was attenuated in virulence compared to the parent strain, with significantly lower bacterial recovery from the lungs and spleens at 3 days postinfection. Moreover, histopathological changes, including an inflammatory cell infiltrate, were more pronounced in the lungs of mice infected with the wild-type parent strain than in those of mice infected with the isogenic bscN mutant. These results implicate type III secretion as an important determinant in the pathogenesis of B. cepacia.     

DFNB79: reincarnation of a nonsyndromic deafness locus on chromosome 9q34.3

Genetic analysis of an inbred Pakistani family PKDF280, segregating prelingual severe to profound sensorineural hearing loss, provided evidence for a DFNB locus on human chromosome 9q34.3. Co-segregation of the deafness trait with marker D9SH159 was determined by a two-point linkage analysis (LOD score 9.43 at θ=0). Two additional large families, PKDF517 and PKDF741, co-segregate recessive deafness with markers linked to the same interval. Haplotype analyses of these three families refined the interval to 3.84 Mb defined by D9S1818 (centromeric) and D9SH6 (telomeric). This interval overlaps with the previously reported DFNB33 locus whose chromosomal map position has been recently revised and assigned to a new position on chromosome 10p11.23–q21.1. The nonsyndromic deafness locus on chromosome 9q segregating in family PKDF280 was designated DFNB79. We are currently screening the 113 candidate DFNB79 genes for mutations and have excluded CACNA1B, EDF1, PTGDS, EHMT1, QSOX2, NOTCH1, MIR126 and MIR602.