The kinetic occipital (KO) region in man: an fMRI study

We used functional magnetic resonance imaging to explore, in individual subjects, the properties of the kinetic occipital (KO) region, which previous position emission tomography studies have shown to be involved in the processing of kinetic boundaries. The KO region was significantly activated in 23/25 subjects tested in the subtraction of uniform motion from kinetic gratings. The KO region is genuinely specialized for processing kinetic boundaries since it is significantly more activated by kinetic gratings than by luminance-defined gratings, uniform motion or transparent motion. This leaves only the kinetic boundaries, created by discontinuities in motion direction, as the specific stimulus aspect, activating the KO region. The KO region is anatomically and functionally distinct from areas MT/V5, V3 and V3A. It also has minimal overlap with the lateral occipital (LO) region. The selective activation of the KO region is robust and relatively immune to changes in stimulus size, spatial frequency and type of kinetic boundary. These results strongly argue for the view that the KO region is a new, separate, functional region in human occipital cortex.      

Prospective monitoring of BK virus replication in renal transplant recipients

Background. BK virus-associated nephropathy (BKVAN) can be diagnosed only with renal graft biopsy. Definitive diagnosis of BKVAN requires demonstration of BK virus (BKV) replication in renal allograft tissues. Non-invasive analysis of urine and blood is considered essential in screening renal transplant recipients.
Patients and methods. This study evaluated prospectively the replication of BKV in plasma and urine with qualitative and quantitative real-time polymerase chain reaction in 32 de novo (group A) and 34 chronic (group B) renal transplant recipients and the long-term impact on graft function.
Results. In group A, 456 samples (228 plasma, 228 urine) were examined and BKV was detected in 31 (31/228, 14%) samples of plasma and 57 (57/228, 25%) samples of urine in 20 (20/32, 62.5%) and 23 (23/32, 72%) recipients, respectively. Incidence of viremia and viruria increased during the first 6 months presenting a peak the third postoperative month (viremia: 28% and viruria: 31%). Immune suppressive treatment with tacrolimus showed significant relation with viremia. Renal graft function in de novo renal transplant recipients remained stable throughout the follow-up period without influence of BKV replication. In group B, incidence of viremia and viruria were 3% (1/34) and 9% (3/34) correspondingly, indicating that after the first post-transplant year the risk of BKV re-activation is diminished.
Conclusion. The highest incidence of BK viremia and viruria is observed the third post-transplantation month, confirming previously published studies in Europe and the United States, and long-term follow up shows that BKV replication decreases significantly after the third post-transplant month and even transient viremia or viruria does not have an impact on renal function.     

Electron microscopic evidence of persistent chlamydial infection following treatment

Chlamydia trachomatis infections of the female and male genital tracts are often asymptomatic and, thus, tend to become persistent. In the persistent state the typical Chlamydia life cycle is arrested and standard antibiotic regimens do not always eradicate this infection. We sought to relate treatment failures in men and women with persistent chlamydial genital tract infections to electron microscopic evidence of chlamydial persistence and with atypical morphological forms of the organism. Of 16 patients with chlamydial persistence following azithromycin treatment, morphological variants of this organism were observed by electron microscopy from one endocervical sample and one male urethral sample. We document the presence of intracellular inclusions containing only reticulate bodies, extracellular monomembrane and polymembrane phagosomes containing elementary bodies and reticulate bodies with abnormal outer membranes in the process of dividing extracellularly. These observations parallel previous in vitro studies of chlamydial persistence under adverse conditions. This capacity of C. trachomatis to undergo atypical morphological alterations in vivo may contribute to its persistence and relative resistance to antibiotics.     

Apolipoprotein E polymorphism, age and coronary heart disease

Plasma concentrations of lipids, lipoproteins, and apolipoproteins (apo) are established risk factors for coronary heart disease (CHD). The knowledge of lipid profile may predict the potential victims of cardiovascular disease before its initiation and progression and offer the opportunity for primary prevention. The most common apo E polymorphism has been found to influence blood lipid concentrations and its correlation with CHD has been extensively investigated in the last decade. At younger ages, death from CHD is influenced by genetic factors, while the genetic effect decreases at older ages where environmental factors may play a more prominent role. If apo E polymorphism is an important genetic factor in the pathogenesis of atherosclerosis, it could affect the age of CHD onset. This review analyses the influence of apo E polymorphism on blood lipids and CHD in respect to age.     

Fifteen year surveillance of echinococcal heart disease from a referral hospital in Greece

Ten cases of hydatid heart disease were treated over a 15-yearperiod (1980–1995). Cysts were located in the left ventricularwall (four patients), right ventricular wall (one patient),interventricular septum (one patient), interatnal septum (onepatient), right atrium (one patient), pericardial cavity (onepatient) and in multiple loci (one patient). Apart from twoasymptomatic cases, clinical manifestations included chest pain(four patients), anaphylactic shock (one patient), constrictivepericarditis (one patient), congestive heart failure (one patient)and arterial embolism (one patient). Computed tomography wasfound useful in the detection of hydatid cysts and also in thedetermination of their morphology. Magnetic resonance was performedin three patients, with satisfactory imaging. Three out of the10 patients died: rupture of pulmonary echinococcal cyst (onepatient), massive pulmonary hydatid embolism (one patient) andrupture of an undiagnosed hydatid cyst of the right atrium duringcannulation for cardiopulmonary bypass (one patient). One otherpatient experienced recurrent systemic embolism and became hemiplegic.Six patients were successfully treated. In five patients, thecysts were excised by open heart surgery, while in one by pericardiectomy.In addition, antiparasitic drugs were successfully used in twopatients with long-term satisfactory results. In conclusion, cardiac echinococcosis is associated with anincreased risk of potentially lethal complications. Newer techniquesof cardiac imaging have helped locate the cysts while surgicalremoval may offer cure. Some patients responded to specificlong-term drug treatment.