Nidovirus infections: experimental model systems of human neurologic diseases

The presence of terminally differentiated slow- and non-dividing cells in the central nervous system (CNS) provides a safe harbor for viral persistence and latency and constitutes a unique immunologic environment for viral infections. Studies of experimental model systems of viral infections of the CNS provide insight into mechanisms of viral persistence and immune-mediated pathology. Nidoviruses are comprised of 2 families of viruses, coronaviruses and arteriviruses, and are common pathogens of humans and a variety of animal species. Both families of viruses contain neurotropic strains that produce experimental neurologic diseases in rodents. These include acute meningitis and encephalitis; acute poliomyelitis; and chronic inflammatory, immune-mediated, demyelination. Coronavirus-induced demyelinating disease mimics many of the pathologic features of Multiple Sclerosis (MS).     

Increased risk of salivary gland tumors after low-dose irradiation

Objective: To assess the risk of neoplastic development among persons exposed to scalp irradiation. Study Design: Historical cohort study initially; prospective follow-up subsequently. Method: Two control groups—population and siblings—matched for age, sex, ethnic origin, and year of immigration. Follow-up from time of irradiation (1950s) until the end of 1991. Linkage with nationwide cancer registry. Results: A 4.5–fold incidence of cancer (P < .01) and a 2.6–fold increase of benign tumors were noted. The mean length of latency period until tumor development was 11 years for malignant tumors and 21.5 years for benign. A clear dose response effect for both cancer and benign tumors was demonstrated. Conclusions: The study confirms the role of radiation in salivary gland carcinogenesis. It indicates a need for better awareness, a comprehensive examination, and long-term follow-up of patients who have been subjected to head and neck radiation.     

Pregnancy outcome after gestational exposure to the new macrolides: a prospective multi-center observational study

Objectives

To determine whether the use of the new macrolides (azithromycin, clarithromycin, roxithromycin) during the first trimester of pregnancy is associated with an increased risk of major malformations.

Study design

In a prospective multi-center study, pregnancy outcome was compared between pregnant women exposed to one of the new macrolides during the first trimester of pregnancy and two comparison groups one exposed to other antibiotics and the other to other non-teratogenic medications. All women enrolled in the study called one of the three participating teratogen information services (TIS). Group 1 macrolides (n = 161), group 2 other antibiotics (n = 213) and group 3 non-teratogens (n = 740).

Results

A total of 161 women exposed to the new macrolides (118 were exposed in the first trimester of pregnancy) and 953 from a comparison groups were followed up. The rate of major malformations in the study group was 4.1% compared to 2.1% in the other antibiotics exposed group (OR = 1.41, 95% CI 0.47–4.23) and 3.0% in the non-teratogens exposed group. The rate of elective terminations of pregnancy was significantly higher in the exposed group in compare to both comparison groups.

Conclusion

Our study, although relatively small sized, suggests that the use of the new macrolides during the first trimester of pregnancy does not represent an increased risk for congenital malformations strong enough for an induced abortion after such an exposure. Elective terminations of pregnancy because of early exposure to these medications should be reconsidered.     

The role of leptin in fetal growth: a short review from conception to delivery

Abnormally high- or low-serum maternal levels and/or levels in placental, umbilical blood, and fetus/neonate are associated with a wide spectrum of complicated pregnancies. Whereas the state of knowledge about mechanisms and pathways involving secondary or tertiary modulators is far from complete, the role of leptin from ovulation and implantation and throughout pregnancy underscores its importance in normal and abnormal states.     

Liver transplantation for children with Wilson disease: comparison of outcomes between children and adults

Arnon R, Annunziato R, Schilsky M, Miloh T, Willis A, Sturdevant M, Sakworawich A, Suchy F, Kerkar N. Liver transplantation for children with Wilson disease: comparison of outcomes between children and adults.
Clin Transplant 2011: 25: E52–E60. © 2010 John Wiley & Sons A/S. Abstract: Liver transplantation (LT) is lifesaving for patients with Wilson disease (WD) presenting with fulminant hepatic failure (FHF) or chronic liver disease (CLD) unresponsive to treatment. Aim: To determine the outcome of LT in pediatric and adult patients with WD. Methods: United Network for Organ Sharing data on LT from 1987 to 2008 were analyzed. Outcomes were compared for patients requiring LT for FHF and CLD after 2002. Multivariate logistic regression was used to determine risk factors for death and graft loss. Results: Of 90 867 patients transplanted between 1987 and 2008, 170 children and 400 adults had WD. The one‐ and five‐yr patient survival of children was 90.1% and 89% compared to 88.3% and 86% for adults, p = 0.53, 0.34. After 2002, 103 (41 children) were transplanted for FHF and 67 (10 children) for CLD. One‐ and five‐yr patient survival was higher in children transplanted for CLD compared to FHF; 100%, 100% vs. 90%, 87.5% respectively, p = 0.30, 0.32. One‐ and five‐yr patient survival was higher in adults transplanted for CLD compared to FHF; 94.7%, 90.1% vs. 90.3%, 89.7%, respectively, p = 0.36, 0.88. Encephalopathy, partial graft, and ventilator use were risk factors for death by logistic regression. Conclusion: LT is an excellent treatment option for patients with WD. Patients transplanted for CLD had higher patient survival rates than patients with FHF.     

Nonmyeloablative conditioning does not prevent telomere shortening after allogeneic stem cell transplantation

BACKGROUND: Stem cell transplantation (SCT) may be associated with premature aging of the hematopoietic stem cells. Telomere length reflects the proliferative history of a cell. In most studies published so far on telomere dynamics after myeloablative allogeneic SCT, recipients had shorter telomeres than their respective donors, thus reflecting "accelerated aging" of hematopoietic cells. We evaluated telomere dynamics in patients who underwent transplantation with nonmyeloablative protocols, assuming that the decreased intensity of chemotherapy might prevent telomere attrition. METHODS: Telomere length was measured using FISH-FACS method. Telomeres of recipients were compared to their respective donors. Twenty-three consecutive patients after nonmyeloablative SCT were evaluated. A control group consisted of 10 donor-recipient pairs after conventional myeloablative transplantation. RESULTS: There was significant telomere shortening in both recipients of nonmyeloablative and myeloablative conditioning (0.487+/-0.65 kb, P=0.003; 0.361+/-0.50 kb, P=0.047 respectively). The extent of telomere shortening in the two groups was not different (P=0.64). There was no correlation between the degree of shortening and parameters such as time interval from transplant, age of donor or recipient, and the number of infused cells. CONCLUSIONS: This is the first study on telomere dynamics after nonmyeloablative conditioning SCT. The study demonstrates significant shortening of telomeres in recipients in spite of decreased intensity conditioning. Results of this study suggest that the main mechanism following transplantation is the proliferative stress imposed upon the stem cells and not direct damage by cytotoxic drugs. The different kinetics of restoration of hematopoiesis and the probable ongoing process of graft-versus-leukemia in the bone marrow do not prevent the attrition of telomeric ends of chromosomes.     

Varicella zoster infection and pulmonary complications

A 34-year-old immunocompetent man with varicella zoster (VZ) infection developed deep vein thrombosis and pulmonary embolism after suffering severe pneumonitis. He recovered after treatment with acyclovir, high-dose steroids, and ventilatory support. The endothelial damage could be a direct link between VZ pneumonitis and pulmonary emboli.