Minimally invasive video-assisted thoracic surgery using radially expanding trocars

We report a new and safer access device for thoracoscopic operation. This radially expanding trocar provides a smaller incision of skin and a lesser visceral, vascular or neural injury than a conventional cannula. Therefore, most of patients undergoing this operation do not feel much pain. Moreover, this device system is more cost effective than a conventional one. We prefer and recommend this minimally invasive technique for video-assisted thoracic surgery.     

Antenatal three-dimensional sonographic features of Pierre-Robin syndrome. Case report

A case of Pierre-Robin syndrome with polyhydramnios is described. Three-dimensional sonography clearly showed fetal micrognathia and hypoplastic ear antenatally. The benefits and advantages of the use of three-dimensional sonography to diagnose Pierre-Robin syndrome in utero are discussed.     

Prevention and treatment of malignant syndrome in Parkinson's disease: a consensus statement of the malignant syndrome research group

We report a consensus statement of the collaborative research group on the prevention and treatment of malignant syndrome (MS) in Parkinson's disease. The syndrome is quite similar to neuroleptic MS. Although sudden withdrawal of levodopa was the most frequent cause, many other precipitating events were found such as intercurrent infections, dehydration, hot weather, discontinuation of other anti-parkinsonian drugs, and "wearing off" phenomenon. Awareness of this syndrome is most important for its early detection and the prompt commencement of treatment. MS should be suspected whenever the body temperature rises above 38 degrees C without an apparent cause. Treatment consists of ample intravenous fluid, cooling the body, anti-parkinsonian drugs (particularly levodopa and bromocriptine), dantrolene sodium, and antibiotics if infection is present. Rhabdomyolysis, disseminated intravascular coagulation, and acute renal failure constitute serious complications.     

Biopterin metabolism in patients with malignant syndrome

We examined the autopsied brains of two parkinsonian patients who had malignant syndrome (MS). Neopterin and biopterin contents, and GTP cyclohydrolase I activity were measured in various region of the brain. We found relatively higher GTP cyclohydrolase I activities in the hypothalamus compared with other regions of the brain from patients with MS. This finding suggested a possible involvement of biopterin metabolism in pathophysiology of MS. This is the first report on biopterin metabolism in the brains of patients with MS.     

Five-year follow-up of patients with partial epilepsies in infancy

The aim of this study is to clarify the long-term outcome of patients with partial epilepsies that begin in the first 2 years of age. Thirty-nine infants who experienced partial epilepsies with onset by 2 years of age were followed until they were at least 5 years of age. Seizure and developmental outcome were investigated in relation to the following items: delayed psychomotor development before onset of seizures; interictal electroencephalogram (EEG) abnormalities; abnormal neuroimaging; family history of epilepsy; and history of neonatal seizures. Thirty-three infants achieved freedom from seizures and 27 achieved normal development. Delayed development before the onset and abnormal interictal EEG correlated with both poor seizure and developmental outcome. Abnormal neuroimaging findings correlated with a poor seizure outcome. A history of neonatal seizures and lack of a family history of epilepsy correlated with poor developmental outcome. The combination of the first four factors predicted a normal outcome with a sensitivity of 0.79 and a specificity of 0.87. The seizure and developmental outcomes were better in this study than those in previous studies. The combination of the four factors will be useful for predicting the outcomes in patients with partial epilepsies in infancy.     

Critical timing of mitochondrial K(ATP) channel opening for enhancement of myocardial tolerance against infarction

Objective The present study was designed to assess the relationship between the timing of a mitoK_ATP channel opener, diazoxide, and its infarct size-limiting effect. Methods In isolated rabbit hearts, infarction was induced by 30 min of global ischemia and 2 h of reperfusion, and infarct size was determined by tetrazolium staining and expressed as a percentage of the left ventricle (%IS/LV). Diazoxide, a mitoK_ATP channel selective opener, and/or 5-hydroxydecanoate (5-HD), a mitoKATP channel blocker, were infused before or after the onset of ischemia. When these agents were infused during the ischemic period, they were dissolved in a hypoxic buffer at concentrations 10-fold higher than those in the pre-ischemic period, and the infusion rate was set at 2 % of the pre-ischemic coronary flow. Results In untreated controls, %IS/LV was 53.2 ± 4.1 (SE). Pretreatment with diazoxide (100 μM) with a 10-min washout period reduced %IS/LV to 7.8 ± 2.4 and this protection was abolished by co-infusion of 5-HD (50 μM). Pre-ischemic infusion of diazoxide without a washout period reduced %IS/LV to 7.3 ± 1.4, and infusion of diazoxide from 10 min after the onset of ischemia also limited %IS/LV to 14.9 ± 4.6. However, diazoxide infusion from 25 min after the onset of ischemia failed to reduce infarct size (%IS/LV = 54.5 ± 7.2). Furthermore, pretreatment with 5-HD (50 μM) also completely abolished the protection afforded by early post-ischemic diazoxide infusion (%IS/LV = 48.3 ± 6.5). Neither infusion of 5-HD nor the anoxic vehicle alone during ischemia modified %IS/LV. Conclusion These findings suggest that opening of mitoK_ATP channels before ischemia and during early ischemia, but not that upon reperfusion, is important for enhancement of myocardial tolerance against infarction. Received: 6 November 2000, Returned for revision: 21 November 2000, Revision received: 24 January 2001, Accepted: 25 January 2001     

Muscle function in 164 men and women aged 20--84 yr

PURPOSE: The purpose of the present study was to investigate the effect of aging in men and women on muscle functional properties, i.e., muscle force and force per unit of cross-sectional area (force/CSA). METHODS: A total of 164 volunteers participated in this study and were divided into five groups according to their chronological age as follows: 20s (20--39 yr old), 40s, 50s, 60s, and 70s (70--84 yr old). Isokinetic (0, 60, 180, and 300 degrees.s(-1)) knee extensor and flexor peak torque, and CSA of the quadriceps femoris (QF) muscle of the mid-thigh were measured. RESULTS: Peak torque during knee extension and flexion was inversely related to age in both men and women. This was the case irrespective of the speed of contraction in both genders (men: r = -0.797 to -0.756, all P < 0.001, women: r = -0.639 to -0.530, all P < 0.001). A significant correlation was observed between CSA of QF and peak torque during isometric knee extension in men (r = 0.827, P < 0.001) and women (r = 0.657, P < 0.001). During isometric contraction, the force/CSA exhibited a significant decrease with increasing age in men (r = -0.518, P < 0.001) but not in women (r = -0.207, NS). CONCLUSION: These results thus suggest that muscle strength losses would be mainly due to a decline in muscle mass in both genders, whereas age-related decline in muscle function in men may also be the result of neural factors, such as muscle recruitment and/or specific tension.     

Renal carcinogenesis, hepatic hemangiomatosis, and embryonic lethality caused by a germ-line Tsc2 mutation in mice

Germ-line mutations of the human TSC2 tumor suppressor gene cause tuberous sclerosis (TSC), a disease characterized by the development of hamartomas in various organs. In the Eker rat, however, a germ-line Tsc2 mutation gives rise to renal cell carcinomas with a complete penetrance. The molecular mechanism for this phenotypic difference between man and rat is currently unknown, and the physiological function of the TSC2/Tsc2 product (tuberin) is not fully understood. To investigate these unsolved problems, we have generated a Tsc2 mutant mouse. Tsc2 heterozygous mutant (Tsc2+/-) mice developed renal carcinomas with a complete penetrance, as seen in the Eker rat, but not the angiomyolipomas characteristic of human TSC, confirming the existence of a species-specific mechanism of tumorigenesis caused by tuberin deficiency. Unexpectedly, approximately 80% of Tsc2+/- mice also developed hepatic hemangiomas that are not observed in either TSC or the Eker rat. Tsc2 homozygous (Tsc2-/-) mutants died around embryonic day 10.5, indicating an essential function for tuberin in mouse embryonic development. Some Tsc2-/- embryos exhibited an unclosed neural tube and/or thickened myocardium. The latter is associated with increased cell density that may be a reflection of loss of a growth-suppressive function of tuberin. The mouse strain described here should provide a valuable experimental model to analyze the function of tuberin and its association with tumorigenesis.     

Dietary prevention of azoxymethane-induced colon carcinogenesis with rice-germ in F344 rats.

The modifying effect of dietary administration of defatted rice-germ and gamma-aminobutyric acid (GABA)-enriched defatted rice-germ on azoxymethane (AOM)-induced colon carcinogenesis was investigated in two experiments with male F344 rats. In the first experiment (the pilot study), the effects of the defatted rice-germ, the GABA-enriched defatted rice-germ and rice-germ on AOM-induced (15 mg/kg body wt once a week for 3 weeks) formation of aberrant crypt foci (ACF) were examined. The latter two preparations (2.5% in the diet) significantly inhibited ACF formation (P < 0.005). In the second experiment, a long-term study of the effects of rice-germ was done. One group was treated with AOM alone, four groups received the carcinogen and were fed the diets containing 2.5% rice-germ or 2.5% GABA-enriched defatted rice-germ for 5 (initiation phase) or 30 weeks (post-initiation phase), two groups were treated with rice-germ or GABA-enriched defatted rice-germ alone and one group was kept on the basal diet. At the termination of the study, dietary exposure to rice-germ during the initiation phase significantly reduced the incidence of colonic adenocarcinoma (71 versus 29%, P < 0.01). GABA-enriched defatted rice-germ or rice-germ during the post-initiation phase also decreased the frequency of colonic adenocarcinoma (71 versus 20%, GABA-enriched defatted rice-germ feeding, P < 0.01; 27%, rice-germ feeding, P < 0.01). These data suggest that constituents of rice-germ are possible dietary preventatives for human colon cancers.