Israel Medical Association Journal

The ubiquitin-proteasome pathway has a central role in selective degradation of intracellular proteins. Among the key proteins degraded by the system are those involved in the control of inflammation, cell cycle regulation and gene expression. With numerous important cellular pathways affected, derangements in the ubiquitin system were shown to result in a variety of human diseases including malignancies, neurodegenerative diseases and hereditary syndromes, and proteasome inhibition was implicated as a potential treatment for cancer and inflammatory conditions. Two proteasome inhibitors are currently under clinical evaluation for multiple myeloma and acute ischemic stroke. The ubiquitin system also has an important function in the immune and inflammatory response. It is involved in antigen processing and presentation to cytotoxic T cells, and the activation of nuclear factor-kappa B – the central transcription factor of the immune system. Since the proteasome is the central source of antigenic peptides that are presented to the immune system, some viruses, such as the Epstein-Barr virus, developed escape mechanisms that manipulate the ubiquitin-proteasome system in order to persist in the infected host. Understanding the mechanisms underlying the production of viral antigens by the ubiquitin-proteasome system may have therapeutic applications such as future development of vaccines.

Background: Primary pulmonary hypertension is a rare disorder, characterized by progressive pulmonary hypertension and right heart failure. It may be familial or sporadic. Mutations in bone morphogenetic protein receptor II (BMPR2), a member of the transforming growth factor-beta receptor superfamily of receptors, underlie many cases of the disorder.

Objectives: To perform molecular analysis of a patient with familial PPH[1] and provide her and her family with suitable genetic counseling.

Methods: DNA was extracted from 10 ml whole blood, and the BMPR2 gene was screened for mutations. Individual exons were amplified by polymerase chain reaction and sequenced. Mutation confirmation and molecular characterization of additional family members was performed using restriction enzyme analysis followed by appropriate genetic counseling.

Results: We identified a novel T to C missense mutation expected to result in substitution of arginine for a conserved cysteine in the ligand-binding domain of BMPR2. Screening of family members demonstrated the presence of the mutation in the father and a younger asymptomatic sister of the index patient.

Conclusions: Molecular diagnosis in PPH allows for identification of at-risk family members and raises the option of earlier diagnosis and possibly instituting earlier treatment in affected individuals. However, molecular screening of asymptomatic family members raises difficult ethical questions that can only be resolved by conducting large multicenter prospective studies in BMPR2 carriers.

The human placenta is the interface between the mother and fetus in the uterus. Until recently it was generally believed that the uterus provides a protective environment for the fetus. It is now accepted that any chemical substance, including any therapeutic agent, administered to a mother is able to permeate across the placental barrier. Unfortunately, the placental transfer of substances and their distribution in the placenta is not well established. Understanding the structure of placental transporters and their function may serve as the ideal tool for drug development and the cure of mother and fetus during pregnancy.
 

Background: Increased levels of high density lipoprotein (over 60 mg/dl) are considered to be a risk factor for ischemic heart disease. However, some patients with high HDL[1] still develop cardiovascular diseases.

Objective: To find out why patients with very high HDL still suffer from cardiovascular diseases.

Methods: We analyzed several risk factors, such as increased lipid peroxidation, hyperhomeocysteinemia and increased release of inflammatory molecules that could be related to the development of vascular disease in patients with high serum HDL levels. Patients with HDL cholesterol levels above 75 mg/dl were selected for this study and were separated into two groups based on the presence of atherosclerotic vascular disease, i.e., those with vascular disease (patients) and those without (controls).

Results: Plasma isolated from the patient group exhibited significantly increased lipid peroxidation by 21% and decreased total antioxidant status by 17%, but there were no differences regarding their serum or their paraoxonase activity. Moreover, both groups exhibited similar levels of serum C-reactive protein, fibrinogen and homocysteine, enabling us to eliminate these risk factors in the etiology of cardiovascular disease in the patient group.

Conclusion: Increased oxidative stress could be one of the factors leading to cardiovascular diseases in patients with high serum HDL levels.

Background: Seroepidemeliogic surveys have provided valuable information on the prevalence and incidence of herpes simplex virus-2 infection in general and in selected populations.

Objective: To review the reliability of traditional diagnostic approaches in herpes simplex virus-2 infection.

Methods: In this cross-sectional study, 472 patients attending a clinic for sexually transmitted disease in 1998-1999 were evaluated for HSV-2 infection through collection of epidemiologic and clinical data.

HSV-2 infection was confirmed by the presence of specific Viral glycoprotein, gG-2, antibody in sera.

Results: The seroprevalence of HSV-2 among clinic attendees was 9.33%. Of these attendees only 22% presented with or reported a history of typical vesicular lesions in the genital area. Infection rate was  higher in patients with multiple sex partners (20.8% vs. 8.7%, P< ( 0.0023 in individuals aged 30 or older (12.6 vs. 6.4%, P = 0.03) and  in the Israeli Jewish population as compared to the Israeli Arab population (11.1% vs. 2.4%, P ~ 0.01). Females with multiple sex partners exhibited higher rates of infection than did their male counterparts (50 vs. 16.1%, P < 0.0275(.

Conclusion: The findings support the need for HSV-2 serologi  testing in patients presenting to STD clinics even when typical genital  lesions are not evident but where risk factors for HSV-2 infection are  identified.
 

Sepsis is an infection-induced inflammatory syndrome that results in a complex network of adaptive and maladaptive alterations in homeostatic mechanisms. Severe sepsis, defined as sepsis associated with acute organ failure, is a serious disease with a mortality rate of 30–50%. The coagulation system, through complex interactions, has an important role in the final outcome of the sepsis-induced inflammatory cascade. A fine and delicate balance that normally exists between anticoagulant mechanisms and the procoagulant response is altered in sepsis. Activated protein C, an endogenous vitamin K-dependent anticoagulant, plays a major role in the down-regulation of the procoagulant arm. It also possesses anti-inflammatory properties. Endothelial damage during sepsis impairs the endothelium-dependent activation of protein C, thus shifting the balance towards thrombosis. This shift may contribute to the development of sepsis-related multi-organ failure. Evidence suggesting that activation of the coagulation system may contribute to sepsis-related morbidity and mortality has led to extensive research attempting to correct the hemostatic defects seen in septic patients. Indeed, a recent randomized controlled trial demonstrated a reduction in overall mortality in patients with severe sepsis treated with APC[1]. In this review we discuss the pathogenesis of the coagulopathy of sepsis, as well as the new therapeutic approaches aimed at correcting the defects in the coagulation system.

Matrix metalloproteinases are a family of enzymes that degrade different components of extracellular matrix. They play an important role in normal physiologic processes of maintaining tissue integrity and remodeling, as in wound healing, processes of development, and regeneration. However, excessive expression of MMP[1] has been observed in many disease states, including rheumatoid arthritis and osteoarthritis, vascular remodeling in atherosclerosis and aortic aneurysm formation, neoplastic processes, macular degeneration and many others.

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