Seminal lactate dehydrogenase C4 (LDH-C4) isozyme activity in infertile men

Lactate dehydrogenase C4 (LDH-C4) is the specific isozyme of LDH produced by germ cells. We measured LDH-C4 activity in seminal plasma from infertile men with oligozoospermia or azoospermia using gel electrophoresis. Total LDH activity in seminal plasma from infertile patients (n = 99) was 2,487 +/- 1,384 IU/l (mean +/- SD). LDH-C4 isozyme activity was detected in 63 out of 75 seminal plasma samples from infertile patients with a mean of 383 +/- 356 IU/l (13.8 +/- 8.6% of total LDH). Sperm count was positively correlated with LDH-C4 (r = 0.298; P < 0.05), but not with any other LDH isozymes or with total LDH. Seminal LDH-C4 was significantly lower in patients with varicoceles (253 +/- 223 IU/l) than without varicoceles (474 +/- 262 IU/l). Six azoospermia patients were treated with hCG and hMG. Three out of four patients whose seminal plasma revealed LDH-C4 activity responded to the treatment, whereas none of the other two patients without seminal LDH-C4 activity did. These results indicate the clinical usefulness of seminal LDH-C4 as a potential marker for seminal epithelium activity in the diagnosis and treatment of male infertility.     

MR and CT findings of craniopharyngioma during and after radiation therapy

Long-term changes in craniopharyngioma treated with radiation therapy (RT) were investigated by computed tomography (CT) and/ or magnetic resonance (MR) imaging. Eight patients with craniopharyngioma were treated with incomplete resection or conservative surgical intervention followed by postoperative RT. The periods of tumor shrinkage were often long and varied (range: 6-68 months, mean: 29.1 months). Temporary enlargement of the solid component of a tumor usually occurs during RT and does not represent tumor progression. Cystic enlargement also occurs sometimes comparatively early after RT, and enlarged cysts often shrink with no treatment or with conservative treatment. These changes should be differentiated from tumor recurrence, with careful follow-up. After shrinkage, small solid or cystic nodules enhanced with contrast medium often remain. Long-term follow-up is necessary to differentiate uncontrolled tumors from controlled tumors with imaging modalities.     

Recombinant adeno-associated viral vectors bring gene therapy for Parkinson's disease closer to reality

The recombinant adeno-associated viral (rAAV) vector is a powerful tool for delivering therapeutic genes into mammalian brains. In rodents and non-human primates, a substantial number of striatal neurons can be transduced with high titer rAAV vectors by simple stereotaxic injection. Efficient and long-term expression of genes for dopamine (DA)-synthesizing enzymes in the striatum restored local DA production and achieved behavioral recovery in animal models of Parkinson's disease (PD). Moreover, sustained expression of a glial cell line-derived neurotrophic factor gene in the striatum rescued nigral neurons and led to functional recovery in a rat model of PD, even when treatment was delayed until after the onset of progressive degeneration. These results suggest that gene therapy using rAAV vectors may become a novel and feasible treatment for PD.     

Rho-kinase contributes to diphosphorylation of myosin II regulatory light chain in nonmuscle cells

Phosphorylation of myosin II regulatory light chain (MRLC) is important for cell motility and cytokinesis in nonmuscle cells. Although the regulation of monophosphorylated MRLC at serine 19 throughout the cell cycle was examined in detail, MRLC diphosphorylation at both threonine 18 and serine 19 is still unclear. Here we found that Rho-kinase has an activity for MRLC diphosphorylation in nonmuscle cells using sequential column chromatographies. Transfection of Rho-kinase-EGFP induced the excess diphosphorylated MRLC and the bundling of the actin filaments. Conversely, the treatment of cells with a specific inhibitor of Rho-kinase, Y-27632, resulted in the decrease of endogenous diphosphorylated MRLC and actin stress fibers. Immunolocalization studies showed that both diphosphorylated MRLC and Rho-kinase accumulated and colocalized at the contractile ring and the midbody in dividing cells. Taken together, it is suggested that Rho-kinase contributes to MRLC diphosphorylation and reorganization of actin filaments in nonmuscle cells.     

The effects of benzodiazepines on event-related potential indices of automatic and controlled processing in schizophrenia: a preliminary report

The effects of benzodiazepines on cognitive function in schizophrenic patients were investigated using event-related potential (ERP) measurement during an auditory selective attention task. In this study, the authors compared the mismatch negativity (MMN) and N2b components between two subgroups of schizophrenic patients: one is comprised of patients who received no benzodiazepines (NT group, n = 7) and the other is comprised of those administered benzodiazepines in the daytime (T group, n = 7). There were no significant differences in MMN and N2b amplitudes between the two subgroups, whereas the N2b latency was significantly prolonged in the T group relative to the NT group. This suggested that benzodiazepines induce delayed stimulus classification processing in schizophrenic patients.     

Application of the OS-EM method to myocardial SPECT: evaluation of artifact reduction using heart phantom with liver object

SPECT images reconstructed by the ordered subsets expectation maximization (OS-EM) method are known to have fewer artifacts induced by the nearly high-count background organs. The aim of this study was to determine whether the OS-EM method is effective in reducing artifacts induced by the high radioactivity of liver compared with the filtered back projection (FBP) method using a heart phantom with a liver object. Heart and liver phantoms were laid to overlap each other by 2 cm, and the liver/heart radioactivity (L/H) ratios were 0:1, 2:1, and 6:1. Short axial images of cardiac SPECT were reconstructed by OS-EM and the filtered back projection (FBP) method, and counts profiles were obtained for both methods. In both methods of image reconstruction, artifactual higher counts in the inferior wall of the heart were observed as the L/H ratio increased. When compared with the L/H ratio of 0:1, the increase in relative counts of the L/H ratio of 2:1 in the inferior wall showed a similar value for both methods (OS-EM: +9.7%, FBP: +11.6%). With the L/H ratio of 6:1, the OS-EM method showed a lesser increase in relative counts of the inferior wall than with the FBP method (OS-EM: +24.5%, FBP: +38.9%). Moreover, the areas of increased counts were smaller. In conclusion, the OS-EM method was thought to be more useful than the FBP method in reducing the increase in artifactual counts caused by the high radioactivity of liver.     

Granular cell tumor of the spinal nerve root: MR findings

We report granular cell tumor in the right SI nerve root, a location which has not been reported previously. The tumor showed heterogeneous hypointensity on T2-weighted images and heterogeneous enhancement. MRI also demonstrated the precise relation between the tumor and the nerve root.     

Telomerase activity in needle biopsied uterine myoma-like tumors: differential diagnosis between uterine sarcomas and leiomyomas.

Preoperative differential diagnoses between uterine sarcomas and leiomyomas are difficult. As telomerase activation is thought to be essential for the immortality of malignant cells, it is considered a potentially useful diagnostic marker. The aim of the present study was to evaluate the potential diagnostic use of measuring telomerase activity in needle biopsy samples to distinguish uterine sarcoma from leiomyoma. Sixty-two patients with suspected uterine sarcomas based on clinical findings or magnetic resonance imaging findings, and who were scheduled for surgery, underwent transcervical ultrasound-guided needle biopsy. Three samples were obtained per patient for histopathological examination and telomerase activity measurement. Telomerase activity was measured using the telomeric repeat amplification protocol and correlated with final histopathological findings of surgical specimens. Of the 62 patients, 6 leiomyosarcomas and 1 endometrial stromal sarcoma (high grade) were diagnosed by histopathology. In 6 of the 7 samples from uterine sarcomas, relatively high telomerase activity (22-102 units) was detected, whereas only low telomerase activity (11-18 units) existed in 3 of the remaining 55 samples from benign or borderline uterine smooth muscle tumors. At a cut-off value of 20 units, sensitivity, specificity, positive predictive, and negative predictive values for detecting uterine sarcoma were 86% (95% confidence interval, 59-100%), 100% (94-100%), 100% (54-100%) and 98% (95-100%), respectively. The results indicated that telomerase activity in needle biopsy samples is a useful diagnostic marker to distinguish uterine sarcoma from leiomyoma.