Regenerating the fibula with beta-tricalcium phosphate minimizes morbidity after fibula resection

The aim of this study was to assess the radiologic and clinical outcome when beta-tricalcium phosphate is used as a bone graft substitute to backfill the fibular defect that is created by harvesting the fibula. Fourteen patients who had fibula resections to be used as bone grafts for bone tumor resections were assessed radiographically. Callus formation bridging the beta-tricalcium phosphate was seen in 12 of 14 patients at an average of 1.4 months after surgery. In these 12 patients the beta-tricalcium phosphate mostly was absorbed and replaced by newly formed bone at an average of 9.3 months after surgery. In all children, beta-tricalcium phosphate was replaced by newly formed bone at an average of 3.2 months after surgery. Only one adult patient had complete regeneration of the fibula. Few patients had continuity between the regenerated fibula and the native fibula. In one patient in whom free vascularized fibula was harvested, regeneration of the fibula was not observed. Clinical functional outcome was not correlated with successful fibula regeneration and union with the native fibula, as determined using radiographs. The results of the study suggest that, in children, regeneration of the fibula by implanting beta-tricalcium phosphate into a bone defect can reduce morbidity of the fibula harvest sites.     

Energy expenditure in males with mental retardation

Previously, we reported that males with mental retardation (MR) (MR group) expended more energy than males without MR (control group) at a given work load. The precise physiological mechanisms for this difference remain unclear. Using the same set of subjects (23 age-, height-, and weight-matched male pairs, mean age: 36.3 y), we examined possible causes for the observed metabolic difference by monitoring physical movements and evaluating the metabolic capability of the skeletal muscles. In the supine position when no body movements were detected for any subjects, oxygen consumption (VO2) and heart rate (HR) were not markedly different between the MR and the control groups. By contrast, in the sitting and standing positions and during walking at 30 and 50 m/min, when significantly larger body movements were monitored in the MR group, VO2 and HR were significantly higher in this group than in the control group. Linear regression analyses, performed separately in the MR and control groups, revealed that the slope of the regression line of HR on relative exercise intensity (%VO2max) during walking, that of VO2 on walking speeds, and that of VO2 on the number of steps in the MR group were almost identical with those in the control group. These results suggest that the capability of skeletal muscles was not so different between the two groups. Thus, the high energy expenditure in the MR group was suggested to be a result of excessive body movements rather than an intrinsic incapability of skeletal muscles.     

Gene silencing in rat-liver and limb grafts by rapid injection of small interference RNA

Genetic modification is a promising therapeutic strategy for organ transplantation. In previous studies, we introduced a nonviral method of gene transfer to donor grafts using an organ-selective injection technique to up-regulate gene expression. Based on the attractive methodology of RNA interference for silencing a particular gene expression, we applied our catheter-based injection method to transfer small interference RNA (siRNA)-green fluorescence protein (GFP) into liver and limb grafts. We first quantified the interfering activity after the systemic delivery of siRNA in the liver of Alb-DsRed2 transgenic (Tg) rats using in vivo bioimaging system. Then, using GFP Tg Lewis rats as donors, transient down-regulation of the GFP expression was achieved both in liver- and limb-transplantation models by the preoperative rapid injection of siRNA. Genetic modification by siRNA may provide new therapeutic options for down-regulation of endogenous antigenicity.     

New approach for laparoscopic surgery of the right colon

BACKGROUND: In patients in whom the ventral aspect of the root of the mesentery was obscured by the adherent greater omentum, laparoscopic surgery is usually abandoned. To forcefully loosen the adhesions by a laparoscopic maneuver may cause inadvertent intestinal injury. We describe a procedure, named the 'retromesen teric approach', which enables a safe laparoscopic right-sided colic operation in such circumstances. PATIENTS AND METHODS: From 2000 to 2003 in our institute, a laparoscopic right-sided colic operation was performed in 21 patients in whom the ventral aspect of the root of the mesentery was obscured by the adherent greater omentum using the retromesenteric approach (RMA; n = 16) and a conventional approach (CA; n = 5). We reviewed the medical records for the operative duration, intraoperative blood loss, conversion rates and postoperative complications. RESULTS: The duration of operation in the RMA group ranged from 75 to 120 (median 95) min, which was shorter than that in the CA group (p < 0.05). Perioperative bleeding in the RMA group ranged from 0 to 115 (median 30) ml, which was smaller than that in the CA group (p < 0.05). No conversion and no postoperative complications were noted in the both groups. CONCLUSIONS: Our new technique, in which the right colon and the ileum are dissected and lifted en bloc from the retroperitoneum, is safe and useful for laparoscopic right-sided colic operation.     

Correlation between suspended particles in the environmental air and causes of disease among inhabitants: cross-sectional studies using the vital statistics and air pollution data in Japan

To identify the diseases that correlate with suspended particle concentration in the ambient air, a cross-sectional epidemiological study was conducted using the annual vital statistics and air pollution estimates of 1881 points throughout Japan. The concentration of suspended particulate matters (SPMs) 10 microm or less in diameter were hypothetically converted to PM(2.5) values (converted PM(2.5) or cPM(2.5)) by using a conversion factor obtained from 25 estimates in Japan. Among various causes of death, a significant correlation was observed between both the SPM and cPM(2.5) (SPM/cPM(2.5)) levels and the age-adjusted death rates of ischemic heart disease or hypertensive heart disease in both genders. Correlation was noted with pneumonia, asthma, chronic bronchitis/emphysema, or lung cancer only in females. Unexpectedly, breast, endometrial, and ovarian cancer also showed significant increases in mortality rates related to the SPM/cPM(2.5) level, suggesting a role for suspended particles in the ambient air with or without gaseous component as a possible endocrine-disrupting, estrogenic agent. Multivariate regression analysis of confounding factors, smoking rate, population density, and hormone-related factors revealed consistent significance of SPM/cPM(2.5) in these diseases.     

Usefulness of L-[methyl-11C] methionine-positron emission tomography as a biological monitoring tool in the treatment of glioma

OBJECT: The authors retrospectively analyzed the data obtained in patients who had undergone L-[methyl-11C] methionine (MET)-positron emission tomography (PET) studies to clarify the relationship between MET uptake and tumor biological features and to discuss the clinical usefulness of MET-PET studies. METHODS: One hundred ninety-four patients with cerebral glioma or suspected glioma underwent PET scanning 20 minutes after injection of MET, whose uptake into the tumor was expressed as a ratio to contralateral healthy brain tissue (T/N ratio). Analyses were performed to determine how MET uptake correlated with tumor pathological features and prognosis. The T/N ratios before and after various treatments were also examined. There were significant differences in the T/N ratio among the nonneoplastic lesions, low-grade gliomas, and malignant gliomas. Furthermore, there were significant correlations between patient survival and pretreatment T/N ratios. Among patients with malignant gliomas, a significant difference in survival was observed between cases with and without postoperative tumor remnant based on elevated MET uptake. The MET uptake was heterogeneous even among the homogeneous tumor areas demonstrated on MR imaging. Malignant pathological features were detected in the areas with the highest MET uptake. The effectiveness of radiotherapy or chemotherapy was expressed as a significantly decreased T/N ratio in some of the tumor types. CONCLUSIONS: The ability of MET-PET to reflect the biological nature of gliomas makes it an excellent method for monitoring active tumor tissue, and treatments based on its findings should provide a powerful clinical protocol in the course of glioma therapy.     

Septic intramuscular embolism in a neutropenic patient with myelodysplastic syndrome accompanied by asymptomatic septic pulmonary emboli

Septic embolisms are rare disorders which are associated with increased mortality and morbidity. We describe a rare case of septic intramuscular embolism accompanied by asymptomatic pulmonary embolism in a neutropenic patient. Methicillin-sensitive Staphylococcus aureus (S. aureus) was detected and multiple nodules were revealed in both thighs and lung. Although he was treated with sensitive antibiotics to .S. aureus, the symptoms remained unchanged during the neutropenic period. Fever subsided rapidly and his thigh pain disappeared after neutropenia resolved. A prompt diagnosis and optimal therapeutic decisions are critical for the reduction of mortality.     

Identification of genes preferentially expressed in articular cartilage by suppression subtractive hybridization

Suppression subtractive hybridization is very effective to enrich differentially expressed genes in two different tissues or cells. We therefore used the technique to identify characteristic genes expressed in rat knee joint articular cartilage as compared to rat costal cartilage. In this study, we revealed that several genes were enriched in a subtracted articular cartilage cDNA library. The most enriched gene is lubricin that is a putative key molecule for joint lubrication. The second gene is milk fat globule epidermal growth factor (EGF) factor 8, MFG-E8 whose expression has never been observed in cartilage. Other enriched genes are known to be expressed in cartilage, however their differential expressions in cartilages have not been necessarily common. The preferential expression of characteristic genes in articular cartilage would provide unique properties to the tissue. Our findings will provide a new view of articular cartilage.     

A copper chelating agent suppresses carbonyl stress in diabetic rat lenses

To clarify whether transition metals are involved in carbonyl stress in diabetic tissues, we observed the effects of a metal chelating agent, trientine (TE) hydrochloride on the levels of methylglyoxal (MG), 3-deoxyglucosone (3-DG), advanced glycation end products, 8-hydroxy-2′-deoxyguanosine (8-OHdG), and polyol pathway metabolites along with semicarbazide-sensitive amine oxidase (SSAO) enzyme activity in lenses from streptozotocin-induced diabetic rats. Lens MG and 3-DG levels were significantly higher in diabetic rats than nondiabetic controls, and TE significantly restored the increase of these compounds. Lens argpyrimidine was also increased in diabetic rats as compared with controls and was significantly reduced by TE. Lens SSAO activity and 8-OHdG were also significantly elevated in diabetic rats, and TE suppressed both of them, whereas TE showed no effect on the polyol pathway metabolites. The results indicate that transition metals play a significant role in the formation of MG and 3-DG via oxidative stress and SSAO activity.     

Renal oncocytosis

Renal oncocytosis is a rare disorder in which numerous oncocytic nodules develop in the kidney. An additional case is reported here. The patient was a 51-year-old woman who had received hemodialysis for 27 years. Nineteen years previously she had developed a tumorous lesion in the right kidney, which had been diagnosed as oncocytoma with laparotomic biopsy. Recently the kidney was removed because of enlargement of the tumor. The renal parenchyma was entirely replaced with numerous brownish nodules. Histologically, the nodules were composed of nests of uniform oncocytic cells. Ultrastructurally, the oncocytic cells contained numerous mitochondria. Immunohistochemical features of the nodules were identical to those of sporadic oncocytomas, that is, immunophenotypes similar to the distal nephron and reactivity with antimitochondrial antigen. Based on these findings, the lesion was diagnosed as renal oncocytosis. It was not possible to determine whether the larger nodules should be diagnosed as oncocytoma or a part of oncocytosis. Additionally, the germ line mutation of the Birt-Hogg-Dubé (BHD) syndrome gene was examined using the genomic DNA obtained from the peripheral lymphocytes, which failed to show any gene alteration. Despite the rare occurrence pathologists and urologists should be aware of renal oncocytosis, as a precursor lesion of renal oncocytoma and chromophobe renal cell carcinoma.