Intracortical inhibition in the human trigeminal motor system.

OBJECTIVE: To investigate the presence and features of short-interval intracortical inhibition (SICI) in the human trigeminal motor system. METHODS: Surface electromyogram (EMG) was recorded from left and right digastric muscles in 7 subjects, along with additional experiments with intramuscular EMG in 2 subjects. Focal transcranial magnetic stimulation (TMS) was used to activate the motor cortex of one hemisphere and elicit motor evoked potentials (MEPs) in digastric muscles on each side, at rest and while subjects activated the muscles at 10% maximal EMG. Paired or single TMS pulses were delivered in blocks of trials, while conditioning TMS intensity and interstimulus interval (ISI) were varied. RESULTS: At rest, paired TMS (3-ms ISI) with conditioning intensities 0.8-0.9x active motor threshold (TA) reduced the digastric MEP amplitude to a similar extent bilaterally. Conditioning at 0.5-0.7TA did not significantly reduce the MEP. MEP amplitude was reduced to a similar extent in both digastric muscles by ISIs between 1 and 4 ms (0.8TA). Voluntary bilateral activation of digastric muscles reduced the effectiveness of conditioning TMS compared to the resting state, with no differences between sides. The similarity of the responses in both digastric muscles was not due to EMG cross-talk (estimated to be approximately 10% in surface records and approximately 2% in intramuscular records), as the intramuscular records showed the same pattern as the surface records. CONCLUSIONS: The effects of paired-pulse TMS on digastric are similar to those reported for contralateral hand muscles, and are consistent with activation of SICI circuits in M1 by conditioning TMS. Our evidence further suggests that the corticomotor representations of left and right digastric muscles in M1 of a single hemisphere receive analogous inhibitory modulation from SICI circuits. SIGNIFICANCE: SICI has been demonstrated in the face area of motor cortex controlling the trigeminal motor system in normal subjects. This method can be used to investigate abnormalities of SICI in movement disorders affecting the masticatory muscles in humans.     

Crataegus monogyna aqueous extract ameliorates cyclophosphamide-induced toxicity in rat testis: stereological evidences

Cyclophosphamide (CP) is extensively used as an antineoplastic agent for the treatment of various cancers, as well as an immunosuppressive agent. However, despite its wide spectrum of clinical uses, CP is known to cause several adverse effects including reproductive toxicity. Crataegus monogyna is one of the oldest pharmaceutical plants that have been shown to be cytoprotective by scavenging free radicals. The present study was conducted to assess whether Crataegus monogyna fruits aqueous extract with anti-oxidant properties, could serve as a protective agent against reproductive toxicity during CP treatment in a rat model. Male Wistar rats were categorized into four groups. Two groups of rats were administered CP at a dose of 5 mg in 5 ml saline/kg/day for 28 days by oral gavages. One of these groups received Crataegus monogyna aqueous extract at a dose of 20 mg/kg/day orally four hours after cyclophosphamide administration. A vehicle treated control group and a Crataegus monogyna control group were also included. The CP-treated group showed significant decreases in the body, testes and epididymides weights as well as many histological alterations. Stereological parameters and spermatogenic activities (Sertoli cell, repopulation and miotic indices) were also significantly decreased by CP treatment. Notably, Crataegus coadministration caused a partial recovery in above-mentined parameters. These findings indicate that Crataegus monogyna may be partially protective against CP-induced testicular toxicity.     

Does anodal transcranial direct current stimulation enhance excitability of the motor cortex and motor function in healthy individuals and subjects with stroke: a systematic review and meta-analysis

The primary aim of this review is to evaluate the effects of anodal transcranial direct current stimulation (a-tDCS) on corticomotor excitability and motor function in healthy individuals and subjects with stroke. The secondary aim is to find a-tDCS optimal parameters for its maximal effects. Electronic databases were searched for studies into the effect of a-tDCS when compared to no stimulation. Studies which met the inclusion criteria were assessed and methodological quality was examined using PEDro and Downs and Black (D&B) assessment tools. Data from seven studies revealed increase in corticomotor excitability with a small but significant effect size (0.31 [0.14, 0.48], p=0.0003) in healthy subjects and data from two studies in subjects with stroke indicated significant results with moderate effect size (0.59 [0.24, 0.93], p=0.001) in favor of a-tDCS. Likewise, studies examining motor function demonstrated a small and non-significant effect (0.39 [-0.17, 0.94], p=0.17) in subjects with stroke and a large but non-significant effect (0.92 [-1.02, 2.87], p=0.35) in healthy subjects in favor of improvement in motor function. The results also indicate that efficacy of a-tDCS is dependent on current density and duration of application. A-tDCS increases corticomotor excitability in both healthy individuals and subjects with stroke. The results also show a trend in favor of motor function improvement following a-tDCS. A-tDCS is a non-invasive, cheap and easy-to-apply modality which could be used as a stand-alone technique or as an adds-on technique to enhance corticomotor excitability and the efficacy of motor training approaches. However, the small sample size of the included studies reduces the strength of the presented evidences and any conclusion in this regard should be considered cautiously.     

In vitro anti-Helicobacter pylori activity of aqueous extract from Persian Oak testa

Objective: Growing problem of antibiotic resistance in Helicobacter pylori, as a common cause of chronic gastritis and even stomach cancer, demands searching for novel candidates of herbal sources. This study is aimed at assessing the antimicrobial activity of aqueous extract obtained from Quercus brantii var. persica seed coat(Testa) on H. pylori isolated from gastric biopsy specimens.Methods: Such specimens were collected from 100 patients presenting with endoscopic gastroduodenal findings. Testa extracts were prepared from Persian Oak forests in the province of Kohgiluyeh and BoyerAhmad, IRAN. H. pylori isolates were obtained by a series of standard bacteriology tests and cell culture,then were confirmed by PCR. The activity of testa extracts towards 25 H. pylori isolates was assessed by well diffusion method, microdilution assay, and a disk diffusion assay in vitro. Results were analyzed statistically by one-way ANOVA analysis.Results: Aqueous extract of testa demonstrated an antimicrobial activity with zone diameters of inhibition ranged from 0 mm to 40 mm. Its inhibitory activity increased simultaneously with increasing extract concentration. The lowest MIC and MBC were both recorded as 2 μg/m L. Anti-H. pylori activity of testa extract was approximately close to tetracycline and metronidazole and less than amoxicillin. A potent extract of testa possessed significant inhibitory activity(P 0.05).Conclusion: Testa extract is suggested as a natural therapeutic source against the gastric H. pylori infection. However, evaluating the in vivo activity of this extract is necessary too.     

Role of external irradiation in high-risk resected colon cancer

BACKGROUND / AIM: The best therapeutic modality for colon cancer "one of the most common malignancies of human being" is surgical resection of primary tumor. Adjuvant chemotherapy can help surgery to have a higher control and survival rate in high-risk resected patients, but the role of radiation therapy is the place of debate. This study was carried out to evaluate the possible role of adjuvant radiotherapy in such cases. MATERIALS AND METHODS: This retrospective trial evaluated 65 eligible patients with surgically resected high-risk colon carcinoma (serosal and/or lymph node involvement), from May 1986 to February 2000. The patients were categorized into two groups. The first group was treated with chemotherapy alone and the other with chemo-radiotherapy. Chemotherapy included 5.FU 500 mg/m2sub/5days for 6-8 courses and radiotherapy consisted 45-55 Gy with 1.5-2 Gy/fraction. Minimum follow-up was 36 months. RESULTS: Mean event-free survival was 140 and 101 months in chemotherapy and combined-therapy groups, respectively (P = 0.099). Local recurrence rate was detected as 9.7% in the chemotherapy arm and 23.5% in the combined-therapy arm (P > 0.1). Treatment-related morbidity and mortality has been significantly higher in the radiation arm (P CONCLUSION: Postoperative external radiation as adjuvant treatment does not improve local control of the patients with colon carcinoma.     

The efficacy and safety of neoadjuvant chemotherapy?+/??letrozole in postmenopausal women with locally advanced breast cancer: a randomized phase III clinical trial

This two-arm randomized clinical study aimed to evaluate the efficacy and safety of neoadjuvant concurrent chemotherapy and letrozole in postmenopausal women with locally advanced breast carcinoma. One hundred and one postmenopausal women aged 50-83 years with pathologically proven locally advanced (clinical stage T3, T4 and/or N2, N3) breast cancer were randomly assigned to receive neoadjuvant chemotherapy alone (control arm, n = 51) or neoadjuvant chemotherapy concurrent with letrozole 2.5 mg (study arm, n = 50). Chemotherapy consisted of a median 4 (range 3-5) cycles of intravenous 5-fluorouracil 600 mg/m(2), doxorubicin 60 mg/m(2), and cyclophosphamide 600 mg/m(2), every three weeks. All patients subsequently underwent modified radical mastectomy approximately two weeks after the last cycle of chemotherapy. Pathologic complete response rates were 25.5% and 10.2% in the study and the control group, respectively (P = 0.049). Similarly, clinical complete response rates were 27.6% and 10.2% in the study and the control group, respectively (P = 0.037). In the subgroup analysis of hormone receptor-positive cases, the complete response rates were more prominent in study group compared with control group. Common treatment-related side effects such as nausea, vomiting, bone marrow suppression, and mucositis were similar in both groups, but hot flush was more prevalent in study group compared with control group (P = 0.023). The addition of letrozole concurrently with neoadjuvant chemotherapy provides a higher clinical and pathologic response rates with acceptable toxicity compared with chemotherapy alone in postmenopausal women with locally advanced sensitive breast cancer.     

Preoperative carotid artery screening in patients undergoing coronary artery bypass graft surgery

BACKGROUND: The incidence of stroke is 2.1-5.2% in bypass surgery patients with a mortality of 0-38%. This study was designed to evaluate the incidence of significant carotid artery stenosis and its related risk factors in candidates for coronary artery bypass graft (CABG) surgery. METHODS: One thousand forty five consecutive candidates for CABG underwent carotid artery Doppler examination in a prospective study. The relation of age, sex, smoking and diabetes history, as well as lipid profile with carotid stenosis, was evaluated. RESULTS: In 1045 CABG candidates with a mean age of 60 years, prevalence of significant carotid stenosis (>60%) was 6.9%. In the patients aged 65 years and older, the rate of significant stenosis was 12.5%. Age >50 years, female gender, hypercholesterolemia and diabetes mellitus are independent risk factors for significant carotid stenosis. CONCLUSIONS: Significant carotid stenosis has an earlier appearance in our study. Cost-effectiveness studies are recommended for revising the previous screening protocols.     

The effects of pyridaben pesticide on gonadotropic,gonadal hormonal alternations,oxidative and nitrosative stresses in Balb/C mice strain

Pyridaben is a pyridazinone derivative, which has been used as an acaricide and insecticide over the past decade throughout the world. Its adverse effect on the male reproductive system is not well established. In normal reproduction, the physiological levels of the gonadotropic as well as gonadal hormones are key factors; an increase in levels of reactive oxygen species (ROS) and nitric oxide stress (NOS) adversely influence reproduction. To study the effects of changes in these hormones and in levels of ROS and NOS after exposure to pyridaben, 80 adult and apparently healthy male Balb/C strain mice were used. The animals were allocated into three groups: controls, test group 1 and test group 2. Test groups 1 and 2 received the toxin at rates of 53 mg/kg body weight and 212 mg/kg body weight, respectively. The durations of the exposure for both groups were 10, 25 and 45 days. A significant decrease was seen in follicle-stimulating hormone (FSH) levels by days 10 (p?<?0.05), 25 (p?<?0.001) and 45 (p?<?0.001) in the low-dose group; however, in the high-dose groups, the reductions in FSH levels 10, 25 and 45 days after exposure were highly significant (p?<?0.001). In both the low- and high-dose groups, a highly significant (p?<?0.001) decrease in the level of luteinizing hormone was observed. Levels of testosterone in the control and different test groups showed a significant difference; in the low-dose group, the difference was significant (p?<?0.01) after 45 days of exposure, but in the high-dose group, it was significant (p?<?0.01) after 25 days of exposure, whereas it was highly significant (p?<?0.001) after 45 days of exposure. The levels of ROS and NOS increased in all test groups.     

Primary localized stages I and II non-Hodgkin’s lymphoma of the nasopharynx: a retrospective 17-year single institutional experience

The aim of this retrospective study was to define the natural history, clinicopathological findings, prognostic factors, and treatment outcome of 43 patients with localized stages I and II primary non-Hodgkin’s lymphoma (NHL) of the nasopharynx, followed up in a single institution over a 17-year period. Forty-three (13 women and 30 men) consecutive patients with localized stages I (N = 12) and II (N = 31) primary nasopharyngeal NHL were treated in our institution between 1990 and 2007. The pathologic reports were classified according to the International Working Formulation (N = 22) or Revised European-American Lymphoma classification (N = 21). The vast majority of patients (88%) were managed with a sequential combination of chemotherapy and radiation therapy. Chemotherapy mainly consisted of 4–8 (median 6) cycles of CHOP regimen (cyclophosphamide, doxorubicin, vincristine and prednisolone). Involved-field radiation therapy with a median dose of 44 Gy was delivered to the primary site and entire cervical lymph nodes. The median age of the patients was 53 years (range, 6 to 86 years). The majority of the patients (70%) had high-grade histology. B-cell types represented 67% of the cases, among which diffuse large B cell was the most common histological subtype. After a median follow-up of 70 months, the 5-year disease-free survival and overall survival were 58.8% and 70.6%, respectively. In multivariate analysis, age less than or equal to 30 years (hazard ratio (HR) = 5.32, 95% confidence interval (CI) = 1.69–16.76), elevated serum lactate dehydrogenase level (HR = 3.69, 95% CI = 1.43–9.51), and modified International Prognostic Index with more than or equal to two risk factors (HR = 17.99, 95% CI = 2.32–139.30) retained statistical significance. Our limited data suggest that primary nasopharyngeal NHL tends to have aggressive histology and unfavorable clinical course with poor outcome, despite a considerably localized disease at the time of presentation and high frequency of complete initial response rates. Combined modality therapy should be considered for the majority of patients with primary localized nasopharyngeal NHL.