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.     

Organisation of common inputs to motoneuron pools of human masticatory muscles.

OBJECTIVE: To determine the pattern of organization of common inputs to the motoneuron pools of individual muscles in the masticatory system. METHODS: Six subjects bit on a rubber-coated wooden splint placed between the upper and lower incisor teeth. We recorded the surface electromyogram (EMG) of co-contracting masseter, temporalis and digastric muscles bilaterally during isometric jaw closing at 5%, 10%, 20% and 40% of maximal voluntary masseter EMG. RESULTS: The cross-correlograms of the EMGs of homologous muscle pairs indicate that there are common synaptic inputs to the motoneuron pools of the left and right masseter, and left and right digastric muscles, but not to left and right temporalis. The amplitude of the central peak in masseter and digastric correlograms increased with bite force. When the activity of ipsilateral muscle pairs was cross-correlated, central peaks were prominent for masseter-digastric and masseter-temporalis muscle pairs, and the peak amplitudes increased significantly with bite force. In contrast, no significant central peak was observed for temporalis-digastric muscle pairs at any level of voluntary biting. CONCLUSIONS: We conclude that there is synchronous modulation of input bilaterally to the masseter muscles and to the digastric muscles but not to the temporalis muscles. There is synchronous modulation of input to ipsilateral masseter-digastric and masseter-temporalis muscle pairs but not to temporalis and digastric muscles. SIGNIFICANCE: The extent of common input to motoneuron pools of muscles acting around a common joint varies for different muscle pairs, and is not simply a function of whether the muscles of the pair are synergists or antagonists.     

Role of Intralesional Bleomycin in the Treatment of Complicated Hemangiomas: Prospective Clinical Study

BACKGROUND: Hemangioma is the most common tumor of infancy. Although it has a basically benign nature and usually spontaneously regresses, a small percentage (5%) have complications that need treatment. Many different therapeutic modalities can be used in this tumor. OBJECTIVE: To investigate the effect of a new method of treatment (intralesional bleomycin injection) in complicated hemangiomas. MATERIALS AND METHODS: In the Department of Radiation Oncology at Nemazee Hospital in Shiraz, Iran, from April 1992 to October 1998, 32 patients with complicated hemangioma were treated with four to six courses of direct injection of bleomycin into the lesion. RESULTS: After a minimum follow-up of 6 years, there was 70 to 100% regression in 18 patients, 50 to 70% in 7 cases, and less than 50% reduction in 7 patients. CONCLUSION: Intralesional injection of bleomycin is an easy, safe, and effective therapeutic modality in complicated cutaneous hemangiomas.     

Aflatoxin B1 effects on ovarian follicular growth and atresia in the rat

For this investigation, 28 female healthy adult Wistar rats were selected. The animals were divided into four groups (n?=?7 per group): control, test group 1, test group 2 and test group 3. Each rat in test groups 1, 2 and 3, received 0.8 ppm, 1.6 ppm and 3.2 ppm aflatoxin B1 (AFB1), respectively, via gavage for a period of 25 days. The control group received distilled water only. All tissue specimens were processed for routine paraffin embedding and serial cross-sections cut at 5–7 μm and stained with haematoxylin–eosin. Both histomorphologic and histomorphometric analysis was performed under light microscopy. An increase in the concentration of AFB1 resulted in a reduction in the population of healthy primordial, primary, secondary and tertiary follicles. The greatest reduction was in seen in group 3 (with 3.2 ppm AFB1/day). In all test groups, due to an increase in AFB1 concentration, in both the right and left ovaries, all types of atretic follicles, including primordial, primary, secondary, and tertiary atretic follicles were significantly increased (P?<?0.01). In conclusion, AFB1 is toxic for all type of ovarian follicles, including non-growing and growing follicles and exerts an atretogenic effect on all types of ovarian follicles. The atretogenic effect of AFB1 is dose dependant. Due to its toxic effects (gametotoxicity), the resting pool of ovarian follicles (primordial follicles) decreases significantly. The ovulatory follicular population either decreases or is completely depleted.     

Unihemispheric concurrent dual‐site cathodal transcranial direct current stimulation: the effects on corticospinal excitability

We aimed to assess the effects of concurrent cathodal transcranial direct current stimulation (c‐tDCS) of two targets in a hemisphere, termed unihemispheric concurrent dual‐site cathodal tDCS (c‐tDCS_UHCDS), on the size of M1 corticospinal excitability and its lasting effect. Secondary aims were to identify the mechanisms behind the efficacy of c‐tDCS_UHCDS and to evaluate the side effects of this new technique. Twelve healthy volunteers received 20 min c‐tDCS under five conditions in a random order: M1 c‐tDCS, c‐tDCS_UHCDS of M1–dorsolateral prefrontal cortex (DLPFC), M1–primary sensory cortex (S1), M1–primary visual cortex (V1) and sham. The M1 corticospinal excitability of the first dorsal interossei muscle was assessed before, immediately after, and 30 min, 60 min and 24 h after the interventions. Short‐interval intracortical inhibition (SICI) and intracortical facilitation (ICF) were also assessed, using a paired‐pulse paradigm. Compared to conventional M1 c‐tDCS, corticospinal excitability significantly increased following c‐tDCS_UHCDS of M1‐DLPFC and M1‐V1 for up to 24 h (P = 0.001). Significant increases in ICF were observed following c‐tDCS_UHCDS of M1‐DLPFC (P = 0.005) and M1‐V1 (P = 0.002). Compared to baseline values, ICF and SICI increased significantly at T₆₀ (P < 0.001) and T_24 h (P < 0.001) following the concurrent c‐tDCS of M1 and V1. Sham c‐tDCS_UHCDS did not induce any significant alteration. The corticospinal excitability increase was mainly accompanied by ICF increase, which indirectly indicates the activity of glutamergic mechanisms. The findings may help us to more fully understand the brain function and develop future motor learning studies. No significant excitability change induced by sham c‐tDCS_UHCDS suggests that there is no placebo effect associated with this new tDCS technique.     

Botulinum toxin injection versus lateral internal sphincterotomy for the treatment of chronic anal fissure: randomized prospective controlled trial

Purpose

Lateral internal sphincterotomy has been the gold standard treatment for chronic anal fissure, but it still carries the risk of permanent damage of the anal sphincter, which has led to the implementation of alternative treatment like botulinum toxin injection. The aim of this randomized prospective controlled trial was to compare the efficacy and morbidity of botulinum toxin injection and lateral internal sphincterotomy in the treatment of chronic anal fissure.

Methods

Fifty consecutive adults with chronic anal fissure were randomly treated with either lateral internal sphincterotomy or botulinum toxin (BT) injection with 50 U BT into the internal sphincter. The complications, healing and recurrence rate, and incontinence score were assessed 2, 3, 6, 12 months after the procedure.

Results

Inspection at the 2-month visit revealed complete healing of the fissure in 11 (44?%) of the patients in the BT group and 22 (88?%) of the patients in the lateral internal sphincterotomy (LIS) group (p?=?0.001). At the 3-month visit, there was no significant difference between the two groups in healing. The overall recurrence rate after 6 months in the BT group was higher than in the LIS group (p?<?0.05). In the 3-month follow-up, the LIS group had a higher rate of anal incontinence compared to the BT group (p?<?0.05). The final percentage of incontinence was 4?% in the LIS group (p?>?0.05).

Conclusions

The treatment of chronic anal fissure must be individualized depending on the different clinical profiles of patients. Botulinum toxin injection has a higher recurrence rate than LIS, and LIS provides rapid and permanent recovery. However, LIS carries a higher risk of anal incontinence in patients.     

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.     

Hydatid cyst of the right ventricle in early pregnancy

Although hydatic cyst disease rarely involves myocardium and endocardium, cardiac echinococcosis, a potentially life-threatening condition, should be managed promptly. We report a case of right ventricle hydatid cyst detected after syncopal attack in a pregnant woman by using echocardiography .     

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.