The severity of sevoflurane-induced malignant hyperthermia.

BACKGROUND: Malignant hyperthermia (MH) is a potentially fatal complication of general anesthesia triggered by volatile anesthetics. In animal studies, sevoflurane has been reported to be a weak triggering agent. The aim of this study was to evaluate the clinical severity of sevoflurane-induced MH compared to isoflurane. METHODS: From the Japanese MH database containing information for 520 MH cases since 1961, we analyzed 147 cases classified by the MH Clinical Grading Scale (CGS) as 'very likely' or 'almost certain', accumulated from 1990 to 2009. Sevoflurane without succinylcholine (S-SCh (-) group) was given to 48 cases, and isoflurane without succinylcholine (I-SCh (-) group) was given to 30. Variables studied were outcome, CGS score, CGS rank, the first MH sign, and time from induction to onset of MH (occurrence time). Clinical signs and maximum laboratory data from six processes of the CGS were also analyzed. Each of the Mann-Whitney U-test or the unpaired t-test was used for group comparisons. RESULTS: Mortality was 8.3% in the S-SCh (-) group and 10.0% in the I-SCh (-) group (P = 0.803). The CGS scores were 53.4 (SD, 12.2) and 52.3 (11.7) (P = 0.691), respectively. The five processes of the CGS did not differ between groups. Median occurrence times were 72.5 minutes (range, 36.3-127.5) and 65.0 minutes (30.0-131.3), respectively (P = 0.890). CONCLUSION: There were no clinically apparent differences between MH triggered by sevoflurane and isoflurane, and thus no evidence to support the postulate that sevoflurane is a weak or weaker MH triggering agent.

Analysis of human cultured myotubes responses mediated by ryanodine receptor 1.

Malignant hyperthermia is a life-threatening condition caused by autosomal dominant mutations in the ryanodine receptor type 1 gene. Identifying patients predisposed to malignant hyperthermia is done through the Ca-induced Ca release test in Japan. We examined the intracellular calcium concentration in human cultured muscle cells and compared the sensitivity of myotubes to ryanodine receptor type 1 activators based on the Ca-induced Ca release rate. We assessed the utility of this method as an identifying test for predisposition to malignant hyperthermia. Muscle specimens were obtained from 34 individuals undergoing the Ca-induced Ca release test. We cultured myotubes from residual material and monitored changes in intracellular calcium concentration after exposure to the ryanodine receptor type 1 activators caffeine, halothane and 4-chloro-m-cresol by measuring fura-2 fluorescence. We determined the half maximal effective concentrations (EC50) for the test compounds in each myotube and calculated cut-off points using receiver operating characteristic curves. Seventeen patients each were classified into the accelerated and non-accelerated groups based on their Ca-induced Ca release rate. The EC50 values for caffeine, halothane and 4-chloro-m-cresol of the accelerated group were significant lower than those of the non-accelerated group (P < 0.001, P < 0.001 and P < 0.001, respectively). The calculated cut-off points of EC50 values for caffeine, halothane and 4-CmC were 3.62 mM, 2.28 mM and 197 microM, respectively. An increased sensitivity to ryanodine receptor type 1 activators was seen in myotubes in the accelerated group. This functional test on human cultured myotubes indicates that the alteration of their intracellular Ca2+ homeostasis may identify the predisposition to malignant hyperthermia.

Effects of propofol on calcium homeostasis in human skeletal muscle.

Malignant hyperthermia is a pharmacogenetic skeletal muscle disorder of intracellular calcium (Ca2+) homeostasis with an autosomal dominant inheritance. The objective of this study was to investigate the safety of propofol by investigating its effects on calcium homeostasis and its effect sites in human skeletal muscles. Muscle specimens were obtained from 10 individuals with predisposition to malignant hyperthermia. In skinned fibre experiments, we measured the effects of propofol on the Ca(2+)-induced Ca2+ release and the uptake of Ca2+ into the sarcoplasmic reticulum. Ca2+ imaging in primary myotubes was employed to analyse propofol-mediated alternations in the Ca2+ regulation and propofol-induced Ca2+ responses in the presence of Ca2+ channel blocker or Ca(2+)-induced Ca2+ release inhibitor. Increased Ca2+ release from the sarcoplasmic reticulum and inhibition of Ca2+ uptake into the sarcoplasmic reticulum were not observed with 100 microM propofol. A rise of Ca2+ was not seen under 100 microM propofol and the EC50 value for propofol was 274.7 +/- 33.9 microM, which is higher than the clinical levels for anaesthesia. Propofol-induced Ca2+ responses were remarkably attenuated in the presence of Ca2+ channel blocker or Ca(2+)-induced Ca+ release inhibitor compared with the results obtained with caffeine. We conclude firstly that propofol is safe for individuals with predisposition to malignant hyperthermia when it is used within the recommended clinical dosage range, and secondly that its mode of action upon ryanodine receptors is likely to be different from that of caffeine.

Propofol-induced changes in myoplasmic calcium concentrations in cultured human skeletal muscles from RYR1 mutation carriers.

Malignant hyperthermia is a pharmacogenetic disorder caused by autosomal dominant mutations in the ryanodine receptor type 1 gene. Propofol has been reported as a safe anaesthetic for malignant hyperthermia susceptible patients but has not been tested on cultured cells from patients with the ryanodine receptor type 1 mutation. The aim of this study was to determine whether propofol could trigger abnormal calcium fluxes in human myotubes isolated from malignant hyperthermia susceptible patients harbouring the native ryanodine receptor type 1 mutation. Muscle specimens were obtained from the patients to diagnose malignant hyperthermia disposition and the calcium-induced calcium release test and molecular genetic analyses were performed. Using the calcium sensitive probe Fura 2, we determined the 340/380 nm wave-length ratios by measuring alterations in calcium homeostasis in isolated myotubes from cultured skeletal muscle specimens. Two patients, one with ryanodine receptor type 1 R2508C and one with the L4838V mutation had accelerated calcium-induced calcium release rates. The 340/380 nm ratios increased when the propofol concentration exceeded 100 microM. The half-maximal activation concentrations (EC50) for propofol from patients 1 and 2 were 181.1 and 420.5 microM, respectively. Increases in calcium concentrations in response to propofol dosage were limited to doses at least 100-fold greater than those used in clinical settings. These observations correlate well with clinical observations that propofol does not trigger malignant hyperthermia in susceptible humans.

Effect of different pedal rates on oxygen uptake slow component during constant-load cycling exercise.

AIM: We hypothesized that an extremely high pedal rate would induce much more type II muscle fibers recruitment even at an early phase of the same absolute work rate compared with normal pedal rates, and would result in changed amplitude of the pulmonary oxygen uptake slow component (VO(2)SC) during heavy constant-load exercise. METHODS: Two square-wave transitions of constant-load exercise were carried out at an exercise intensity corresponding to a VO(2) of 130% of the ventilatory threshold. The amplitude of the VO(2)SC in phase III during heavy constant-load exercise was determined at normal (60 rpm) and extremely high pedal rates (110 rpm). The VO(2) kinetics were analyzed by nonlinear regression. RESULTS: Although the absolute work rates were almost identical in the two pedal rates cycling exercise, the amplitude of the VO(2) in phase II (phase II amplitude), end-exercise VO(2) (EEVO(2)) and blood lactate accumulation ([La]) were significantly greater at 110 rpm than at 60 rpm (2 260+/-242 vs 1.830+/-304 mL.min(-1) for phase II amplitude; P<0.01, 2 350+/-265 vs 1 709+/-342 mL.min(-1) for EEVO(2); P<0.01, 6.4+/-1.3 vs 3.2+/-1.3 mmol.L(-1) for [La]; P<0.01, respectively). The amplitude of the VO(2)SC in phase III also revealed a significantly higher value at 110 rpm compared with 60 rpm (416+/-73 vs 201+/-89 mL.min(-1), P<0.01). In spite of the appearance of greater VO(2)SC at 110 rpm, no corresponding changes in integrals of the electromyography (EMG) signal and mean power frequency were observed. CONCLUSIONS: The results of this study indicate that the amplitude of the VO(2)SC was greater in higher pedal rate during the same work rate constant-load cycling exercise, which might be associated with a progressive increase in the adenosine triphosphate requirement of already recruited muscle fibers in exercising muscle.

Haplotype analysis of a 100 kb region spanning TNF-LTA identifies a polymorphism in the LTA promoter region that is associated with atopic asthma susceptibility in Japan.

BACKGROUND: The tumour necrosis factor (TNF) gene family, which includes TNF, LTA, and LTB, is located consecutively on human chromosome 6p21 region, which has been linked to asthma by several genome-wide screens. (LTA, lymphotoxin-alpha; LTB, lymphotoxin-beta). OBJECTIVE: The aim of the present study was to determine whether genes on 6q21 are related to development of atopic asthma. Methods We screened for mutations in the coding and promoter regions of genes in the TNF-LTA region, including BAT1, NFKBIL1, LTA, TNF, LTB, AIF, and BAT2, and conducted a transmission disequilibrium test of 41 polymorphisms in 137 families identified through pro-bands with childhood-onset atopic asthma. (BAT1, HLA-B-associated transcript 1; NFKBIL1, nuclear factor of kappa light polypeptide gene enhancer in B cells inhibitor-like 1; AIF, allograft inflammatory factor 1). RESULTS: Haplotypes of the LTA/TNF linkage disequilibrium block were associated significantly with asthma (global P=0.0097). Transmission patterns of the common haplotypes to asthmatic offspring were predicted by a single-nucleotide polymorphism in the LTA promoter region. The G allele of the LTA-753G/A polymorphism was transmitted preferentially to asthma-affected individuals (P=0.001). Luciferase reporter assays with constructs containing the 5' and 3' flanking regions of the LTA gene showed 30-50% lower transcriptional activity when the -753A allele was present than that of other haplotypes. CONCLUSION: Our results suggest that LTA is one of the genes that contributes to susceptibility to atopic asthma, and that the association of the TNF/LTA haplotypes to asthma may be defined by the polymorphism in the LTA promoter region in the Japanese population.

The accumulation of angiostatin-like fragments in human prostate carcinoma.

PURPOSE: Angiostatin, a potent inhibitor of angiogenesis and, hence, the growth of tumor cell metastasis, is generated by a proteolytic enzyme from plasminogen. However, its localization and specific enzymes have yet to be ascertained in human tissue. EXPERIMENTAL DESIGN: To elucidate the generation and the localization of angiostatin in prostate carcinoma, we examined angiostatin generation in a panel of human prostate cancer cell lines and performed immunohistochemistry with the antibodies to angiostatin and prostate-specific antigen (PSA), a potent proteolytic enzyme of angiostatin in 55 cases of prostate carcinoma. RESULTS: We demonstrated that the lysates of human prostate carcinoma cell lines could generate angiostatin-like fragments from purified human plasminogen but could not generate angiostatin in the absence of exogenous plasminogen. The fragmented proteins were reacted with the monoclonal antibody specific for plasminogen lysine-binding site 1 (LBS-1). Immunohistochemically, the intracytoplasmic immunostaining of LBS-1 was positive in 87.3% (48 of 55) of prostate carcinoma cases, and the immunostaining of miniplasminogen was negative in all cases. There was a significant relationship between the positive immunostaining of LBS-1 and Gleason score (P = 0.0007). The intracytoplasmic immunostaining of PSA was positive in 37.0% (20 of 54) of prostate carcinoma cases, but there was no significant relationship between the expression of PSA and Gleason score, or between the positive immunostaining of LBS-1 and PSA. CONCLUSIONS: These findings suggest that angiostatin is generated by prostate carcinoma cells and is accumulated within the cytoplasm. In addition, the generation of angiostatin-like fragments was correlated with tumor grade; however, PSA may not be the only enzyme for angiostatin generation in human prostate carcinoma.

Metastatic adrenal tumor from clear-cell renal cell carcinoma: a pitfall of chemical shift MR imaging.

We present a case of adrenal metastasis from clear-cell renal cell carcinoma in which presence of a small amount of fat was shown on chemical shift gradient-echo magnetic resonance imaging. Radiologists should be aware that signal loss of the adrenal tumor on out-of-phase gradient-echo images does not always suggest the diagnosis of benign adenoma, particularly in patients with a history of renal cell carcinoma.

High expression of the Cap43 gene in infiltrating macrophages of human renal cell carcinomas.

We used suppression subtractive hybridization to identify highly expressed genes in the cancerous region of human renal cell carcinoma (RCC) compared with noncancerous tissue. Nine genes were identified to show increased expression in the cancerous region compared with the noncancerous region. The nine genes included thymosin beta4, secreted protein acidic and rich in cysteine (SPARC), Cap43, ceruloplasmin, serum amyloid A, osteopontin, heat shock protein 90 (HSP90), LOT1, and casein kinase I. Of these 9 genes, in situ hybridization with 10 clinical samples consistently showed a strong expression of Cap43 mRNA in infiltrating macrophages in RCCs, but not in cancer cells proliferating in an alveolar pattern. However, Cap43 mRNA was also apparently detected in epithelial cells of the renal proximal tubuli in noncancerous tissue. The higher expression of the Cap43 gene in the cancerous region of RCCs appears to depend on macrophage infiltration. Moreover, treatment with phorbol ester resulted in enhanced expression of the Cap43 gene in human monocytic cells in vitro. The expression of the Cap43 gene in infiltrating macrophages is discussed in association with the differentiated or activated status of monocyte/macrophage.

A case of bladder pheochromocytoma.

The clinical picture of bladder pheochromocytoma is usually typical; however, the diagnosis is occasionally delayed because of the rarity of this neoplasm. We report a case of unsuspected bladder pheochromocytoma in which the patient had a hypertensive episode during transurethral resection. A 67-year-old male presented with the chief complaint of painless macrohematuria. Cystoscopy revealed a submucosal tumor on the right lateral wall of the bladder. The tumor was operated on transurethrally, followed by partial cystectomy. The pathological diagnosis was pheochromocytoma, primarily occurring in the bladder. Treatment of this lesion requires a high degree of clinical suspicion based on the patient's symptom complex in order to enable adequate preparation prior to surgical manipulation.

Inhibitory effects of flavonoids on rabbit heart carbonyl reductase.

The inhibitory effects of flavonoids (galangin, kaempferol, quercetin, myricetin, morin, and taxifolin) on rabbit heart carbonyl reductase (RHCR) were investigated using 4-benzoylpyridine (4BP) as the substrate. The stereochemical characteristics of the flavonoids were found to be a factor determining their inhibitory potencies toward RHCR. Furthermore, the lipophilicity, and the scavenging or antioxidative effects of the flavonoids were likely to complicate the structure-activity relationship of their inhibitory effects on RHCR. Quercetin inhibited RHCR uncompetitively with respect to NADPH and competitively with respect to 4BP, suggesting that it competes with 4BP at the substrate-binding site of RHCR. RHCR efficiently reduced benzoquinones (1,4-benzoquinone and 2-methyl-1, 4-benzoquinone) and naphthoquinones (1,4-naphthoquinone and menadione). Galangin was a potent inhibitor of RHCR when menadione was used as the substrate, and prevented the formation of the superoxide anion radical in the presence of RHCR, NADPH, and menadione. Flavonoids may be useful compounds for suppressing the cardiotoxicity of quinones by inhibiting RHCR.

Significant evidence for linkage of febrile seizures to chromosome 5q14-q15.

Febrile seizures (FSs) represent the most common form of childhood seizure. In the Japanese population, the incidence rate is as high as 7%. It has been recognized that there is a significant genetic component for susceptibility to this type of seizure. Two putative FS loci, FEB1 (chromosome 8q13-q21) and FEB2 (chromosome 19p), have been mapped. Furthermore, a mutation in the voltage-gated sodium (Na(+))-channel beta1 subunit gene ( SCN1B ) at chromosome 19q13.1 was identified in a family with a clinical subset, termed generalized epilepsy with febrile seizures plus (GEFS(+)). These loci are linked to some large families. In this study, we conducted a genome-wide linkage search for FS in one large family with subsequent linkage confirmation in 39 nuclear families. Significant linkage was found at D5S644 by multipoint non-parametric analysis using GENEHUNTER ( P = 5.4 x 10(-6)). Estimated lambda(s)at D5S644 was 2.5 according to maximum likelihood analysis. Significant linkage disequilibria with FS were observed at the markers D5S644, D5S652 and D5S2079 in 47 families by transmission disequilibrium tests. These findings indicate that there is a gene on chromosome 5q14-q15 that confers susceptibility to FSs and we call this gene FEB4.

Negative C-reactive protein in children with bacterial infection.

PURPOSE: To evaluate the practical value of initial C-reactive protein (CRP) in the diagnosis of bacterial infection in children. METHODS: The subjects comprised 11 children, six boys and five girls, aged 3 months through to 3 years (median age 16 months), whose initial CRP levels were < 1.0 mg/dL despite bacterial infection. C-reactive protein was quantitated at the first medical examination by nephelometry. RESULTS: The diagnosis was urinary tract infection (n = 4), bacterial meningitis (n = 2), sepsis (n = 2), pneumonia (n = 2) and arthritis of the hip joint (n = 1). The CRP levels were significantly elevated during the course of infection, ranging from 7.6 to 28.5 mg/dL. The bacterial etiology was non-specific. Eight patients were examined within 12 h of onset, three exhibited negative CRP values despite the duration of the insult over 12 h. Six patients were tentatively diagnosed as having a bacterial infection, but the other five were not. Each patient was treated, leading to a favorable outcome without any serious complications. CONCLUSIONS: Low levels of CRP do not rule out the possibility of bacterial infection in children. The initial value of CRP may be negative, even in patients with severe bacterial infection or even after 12 h from onset. The data suggest that pediatricians should consistently be aware of the possibility of bacterial infection even if the initial CRP test result is negative and that serial CRP measurements appear to be practical.

Inhibition of rabbit heart carbonyl reductase by fatty acids.

The inhibition of rabbit heart carbonyl reductase (RHCR) by fatty acids was examined using 4-benzoylpyridine (4BP) as a substrate. The inhibitory potency of saturated fatty acids increased with elongation in the carbon chain from caprylic acid to myristic acid, but decreased with further elongation. Myristic acid with 14 carbon atoms most strongly inhibited RHCR. All of the unsaturated fatty acids tested strongly inhibited RHCR; the cis-isomers were more potent inhibitors than the corresponding trans-isomers. The methyl esters and alcohols, which lack a carboxyl group, derived from fatty acids did not exert a significant inhibitory effect on RHCR. These results indicate that the existence of a proper length of carbon chain, double bond(s), and a carboxyl group in a fatty acid molecule is important for RHCR inhibition. We also propose the possibility that myristic acid at low concentrations inhibits the reduction of 4BP by interacting with a binding site other than the coenzyme- and substrate-binding sites of RHCR.

[A case of prostate cancer associated with osteolytic bone metastases].

It is well known that prostate cancer metastasizes bone with osteoblastic change and that osteolytic change is rare. We report a case of prostate cancer that had bone metastases which were all osteolytic. A 62-year-old man was referred to our department because of abnormal prostatic acid phosphatase and pain in his right upper arm. Digital examination revealed an enlarged and hard prostate. A computed tomographic scan revealed multiple osteolytic changes and a bone scintigraphy was positive at these sites. Histopathology of both prostate and humerus showed poorly differentiated adenocarcinoma. He received castration and antiandrogen as hormonal therapy, but the patient's prostate specific antigen did not normalize. Therefore this case was suspected to be hormone-refractory prostate cancer.

Differing expression of MMPs-1 and -9 and urokinase receptor between diffuse- and intestinal-type gastric carcinoma.

Gastric cancer is classified into intestinal and diffuse types, which exhibit different biological behavior. Urokinase-type plasminogen activator (uPA), its receptor (uPAR) and matrix metalloproteinases (MMPs)-1 and -9 are considered to play important roles in cancer invasion and metastasis. We have already suggested a functional duality of these matrix-degrading enzymes/factors; they may also be involved in the matrix turnover (remodeling) or host immune/inflammatory reactions as far as they are expressed by host cells. We performed a retrospective study on the immuno-histochemical expression of these enzymes/factors in surgical specimens from patients with gastric cancer, including 26 with the diffuse and 78 with the intestinal type. We also evaluated macrophages since they are major sources of uPAR. The positivity rate for uPA in cancer cells was significantly lower in diffuse-type than in intestinal-type. Stromal expression was seen mainly along the invasive margin (tumor-host interface). The degree of stromal expression of uPAR and MMP-9 and the macrophage number were markedly decreased in diffuse-type compared with intestinal-type. Stromal expression of uPAR and macrophage number in intestinal-type were higher in patients without liver metastasis than in patients with liver metastasis, while uPA expression in cancer cells was more pronounced in patients with liver metastasis. Studies using frozen sections revealed that the expression of MMP-1, restricted to the stromal area, was more decreased in diffuse-type (18 patients) than in intestinal-type (21 patients). Our results show that the in situ expression of matrix-degrading enzymes/factors in gastric cancer is significantly more diminished in diffuse-type than in intestinal-type, suggesting a multifunctional aspect of the matrix-degradation process in cancer tissue.

Another observation of microphthalmia in an XX male: microphthalmia with linear skin defects syndrome without linear skin lesions.

A case of microphthalmia with Xp microdeletion is reported. The patient was a boy who showed bilateral microphthalmia with corneal opacities, hypospadias without evidence of hypogonadism, and a conduction disturbance of the heart (Wenckebach conduction). No skin lesion was discerned. High-resolution chromosome analysis revealed the karyotype of 46,X,del(X)(p22). The phenotype was considered to be microphthalmia with linear skin defects (MLS) syndrome without skin lesions. Polymerase chain reaction and fluorescence in-situ hybridization analyses revealed that the chromosome aberration resulted from an X;Y translocation: the presence of pseudoautosomal boundary Y and the sex-determining region of Y was confirmed, while Xp deletion involving the region distal to DXS1129 was ascertained. Thus the chromosome designation using the ISCN 1995 nomenclature is 46,X,der(X),t(X;Y)(p22.13;q11.2). Despite the absence of skin lesions, the Xp deletion of our patient corresponded to those of previously reported typical cases of MLS syndrome. Our observation further supports the current hypothesis that the phenotypic variation of MLS syndrome represents tissue-different X inactivation rather than different genetic effects of two contiguous genes.