Correlation between cardiac output and reversibility of rocuronium-induced moderate neuromuscular block with sugammadex.

BACKGROUND: The aim of this study was to evaluate the correlation between cardiac output (CO) and reversibility of rocuronium-induced moderate neuromuscular block with sugammadex in elderly patients. METHODS: Fifty elderly (≥ 65 years) patients were enrolled in this study. During 1.0-1.5% end-tidal sevoflurane and remifentanil anaesthesia, contraction of the adductor pollicis muscle in response to ulnar nerve stimulation was acceleromyographically quantified. All patients initially received 1 mg/kg rocuronium followed by 0.2 mg/kg whenever the second twitch T2 of the train-of-four (TOF) response reappeared. CO was measured throughout the study using a FloTrac™/Vigileo™ monitor. After completion of surgery and at the reappearance of T2, the time required for a bolus dose of 2 mg/kg sugammadex to facilitate recovery to a TOF ratio of 0.9 was recorded, and its correlation with CO was analysed. RESULTS: Adequate recovery of neuromuscular block was achieved after sugammadex in all patients. Mean CO at the time of reversal with sugammadex was 5.3 l/min (1.3), and recovery time to a TOF ratio of 0.9 was 173.4 s (54.8). A statistically significant inverse correlation was seen between the time to recovery to a TOF ratio of 0.9 and CO [reversal time (s) = -27.7·CO + 298.7, R(2) = 0.461, P < 0.0001]. CONCLUSIONS: The time to reach a TOF ratio of 0.9 following sugammadex is dependent on CO in elderly patients.

The change of hemodynamics and heart rate variability on bathing by the gap of water temperature.

Bathing in Japanese style may carry negative effects as water pressure on the chest and thermal stimulus on hemodynamics take place. We have explored the influence of bathing in high temperature water on the change of heart rate variability (HRV). Fourteen young healthy male adults, ageing in range from 28 to 42 years old (the average was 35.8 years old) were selected and took a hot water bath (38 and 41 degrees C) for 15 min long. Bathing in 38 degrees C water brought no significant change in heart rate (HR) and blood pressure (BP), and the HR in 41 degrees C increased in early stage. In HRV, high frequency (HF) power did not have significant change with little increase in early stages of bathing in 38 degrees C and decreased continuously in 41 degrees C. Low frequency (LF) power and very low frequency (VLF) power decreased gradually in later stages of bathing, but the degree of decrease was larger in 41 degrees C. In this study, data concerning dizziness after bathing at 41 degrees C was obtained (we named it as a "dizzy case"). HF and LF trends in this case followed the same pattern in comparison with others' average, but the decrease was larger. Additionally, there was no increase in the LF/HF at later stage of bathing. It is thought that this reflects a decreased in autonomic nerve activity. In normal subjects the VLF increased in later stages of 38 and 41 degrees C bathing, but in the dizziness-experiencing subject, the increase was very significant. It is conceivable that this reflected excessive parasympathetic reflex. Except the dizzy case HF decreased continuously in later stage of bathing in both 38 and 41 degrees C, but VLF slightly increased. Recently there was an express opinion that the VLF correlates with the prognosis; therefore the change of VLF in this study is very interesting. Based upon the results of this study we propose that the optimum period of time for bathing in water 41 degrees C in temperature is 5 min or less, and that for water 38 degrees C in temperature is 10 min or less.

Combination of boron and gadolinium compounds for neutron capture therapy. An in vitro study.

In neutron capture therapy, the therapeutic effect of the boron compound is based on alpha particles produced by the B(n, alpha) reaction while with the gadolinium compound the main radiation effect is from gamma rays derived from the Gd(n, gamma) reaction. The uptake and distribution within the tumor may be different among these compounds. Thus, the combination of the boron and gadolinium compounds may be beneficial for enhancing the radiation dose to the tumor. Chinese hamster fibroblast V79 cells were used. For the neutron targeting compounds, 10B (BSH) at 0, 5, 10, and 15 ppm, and 157Gd (Gd-BOPTA) at 0, 800, 1600, 2400, 3200, and 4800 ppm, were combined. The neutron irradiation was performed with thermal neutrons for 30 min. (neutron flux: 0.84 x 10(8) n/cm2/s in free air). The combination of the boron and gadolinium compounds showed an additive effect when the gadolinium concentration was lower than 1600 ppm. This additive effect decreased as a function of gadolinium concentration at 2400 ppm and resulted in no additive effect at more than 3200 ppm of gadolinium. In conclusion, the combination of the boron and gadolinium compounds can enhance the therapeutic effect with an optimum concentration ratio. When the gadolinium concentration is too high, it may weaken the boron neutron capture reaction due to the high cross-section of gadolinium compound against neutrons.

Additive effect of BPA and Gd-DTPA for application in accelerator-based neutron source.

Because of its fast metabolism gadolinium as a commercial drug was not considered to be suitable for neutron capture therapy. We studied additive effect of gadolinium and boron co-administration using colony forming assay. As a result, the survival of tumor cells with additional 5 ppm of Gd-DTPA decreased to 1/10 compared to the cells with boron only. Using gadolinium to increase the effect of BNCT instead of additional X-ray irradiation might be beneficial, as such combination complies with the short-time irradiation regimen at the accelerator-based neutron source.

Hyaluronic acid as a potential boron carrier for BNCT: Preliminary evaluation.

Hyaluronic acid (HA), a nonimmunogenic, biocompatible polymer found in different biological tissues, has the potential to attach to CD44 receptors on the surface of certain cancer cells, where the receptor is overexpressed compared with normal cells. Boron-hyaluronic acid (BHA) was tested for its feasibility as a potential agent for BNCT. BHA with low-viscosity 30 kDa HA could be administered by intravenous injection. The compound showed a certain degree of cytotoxicity and accumulation in C6 rat glioma cells in vitro. Instability of the chelate bonds between boron and HA and/or insufficient specificity of CD44 receptors on C6 cells to BHA could account for the insufficient in vitro accumulation. To ensure the future eligibility of BHA for BNCT experiments, using alternative tumor cell lines and chemically securing the chelate bonds or synthesizing BHA with boron covalently attached to HA might be required.

Cerebral autoregulation in young spontaneously hypertensive rats. Effect of sympathetic denervation.

Autoregulation of cerebral blood flow was studied with the hydrogen clearance method during development of hypertension in young spontaneously hypertensive rats. To examine the influence of sympathetic nerves on autoregulatory range, the unilateral superior cervical ganglion was removed 2 hours or 2 or 5 weeks before the study. Wall-to-lumen ratio of cerebral arteries was determined with freeze substitution technique. Basal blood pressures were 87 +/- 1 mm Hg (mean +/- SEM) at 4 weeks of age, 105 +/- 2 at 6 weeks, and 126 +/- 3 at 9 weeks, although resting cerebral blood flow was unchanged. Initially, cerebral blood flow remained relatively constant when the blood pressure was raised by intravenous infusion of phenylephrine. The upper limits of cerebral blood flow autoregulation in these groups were 110 +/- 4 mm Hg, 126 +/- 7, and 159 +/- 6 respectively. Acute ganglionectomy significantly lowered the upper limits (p less than 0.05), but chronic denervation did not affect the autoregulatory range. The wall-to-lumen ratios of cerebral arteries were 0.136 +/- 0.007 at 4 weeks and 0.130 +/- 0.005 at 9 weeks. These differences were not significant, nor did sympathetic denervation alter the ratio. These results indicate that (1) the upward shift of the autoregulation is closely related to a rise in the basal blood pressure, (2) acute interruption of sympathetic nerves modulates the autoregulatory range, and (3) adaptation of cerebral blood flow autoregulation to early developmental hypertension may be attributed to factors other than vascular smooth muscle hypertrophy.

QSAR model for drug human oral bioavailability.

The quantitative structure-bioavailability relationship of 232 structurally diverse drugs was studied to evaluate the feasibility of constructing a predictive model for the human oral bioavailability of prospective new medicinal agents. The oral bioavailability determined in human adults was assigned one of four ratings and analyzed in relation to physicochemical and structural factors by the ORMUCS (ordered multicategorical classification method using the simplex technique) method. A systematic examination of various physicochemical parameters relating primarily to absorption, and structural elements which could influence metabolism, was carried out to analyze their effects on the bioavailabilty classification of drugs in the data set. Lipophilicity, expressed as the distribution coefficient at pH 6.5, was found to be a significant factor influencing bioavailability. The observation that acids generally had better bioavailability characteristics than bases, with neutral compounds between, led to the formulation of a new parameter, Delta log D (log D(6.5) - log D(7.4)), which proved to be an important contributor in improving the classification results. The addition of 15 structural descriptors relating primarily to well-known metabolic processes yielded a satisfactory QSAR equation which had a correct classification rate of 71% (97% within one class) and a Spearman rank correlation coefficient (R(s)) of 0.851, despite the diversity of structure and pharmacological activity in the compound set. In leave-one-out tests, an average of 67% of drugs were correctly classified (96% within one class) with an R(s) of 0.812. The relationship formulated identified significant factors influencing bioavailability and assigned them quantitative values expressing their contribution. The predictive power of the model was evaluated using a separate test set of 40 compounds, of which 60% (95% within one class) were correctly classified. Since the necessary physicochemical parameters can be calculated or estimated and the structural descriptors are obtained from an inspection of the structure, the model enables a rough estimate to be made of the prospective human oral bioavailability of unsynthesized compounds. Also, the model has the advantage of transparency in that it indicates which factors may affect bioavailabilty and the extent of that effect. This could be useful in designing compounds which are more bioavailable. Refinement of the model is possible as more bioavailability data becomes available. Potential uses are in drug design, prioritization of compounds for synthesis, and selection for detailed studies of early compound leads in drug discovery programs.

Acute renal failure and degenerative tubular lesions associated with in situ formation of adenovirus immune complexes in a patient with allogeneic bone marrow transplantation.

We describe the development of acute renal failure and degenerative tubular lesions associated with local immune deposits in a patient with allogeneic bone marrow transplantation. A 21-year-old man with an acute myelocytic leukemia received a bone marrow graft from a cousin mismatched for a single HLA-DR locus antigen. Hemorrhagic cystitis due to adenovirus type 11 infection occurred 26 days after transplantation, and 17 days later the patients developed acute renal failure. A study of renal tissue obtained by needle biopsy showed degenerative and necrotic lesions, especially in the distal part of the nephron. By electron microscopy adenovirus type 11 particles were found in the nuclei of tubular cells and in cellular debris in tubular lumina. By immunofluorescence technique, granular immune deposits containing adenovirus type 11 related antigen(s), immunoglobulins, C3, and membrane attack complex (MAC) C5b-9 of the complement system were detected along the tubular basement membranes but not in glomeruli. The patient's IgG did not bind to normal human kidneys. These findings suggest that adenovirus type 11 directly induced acute tubular damage, and that the tubular immune deposits were formed "in situ" by viral antigens and circulating viral antibody.

Cell cycle dependence of boron uptake from two boron compounds used for clinical neutron capture therapy.

In neutron capture therapy, it is important that the boron is selectively uptaken by tumor cells. In the present study, we used flow cytometry to sort the cells in the G0/G1 phase and those in the G2/M phase, and the boron concentration in each fraction was measured with inductively coupled plasma atomic emission spectroscopy. The results revealed that sodium borocaptate and boronophenylalanine (BPA), were associated with higher rates of boron uptake in the G2/M than in the G0/G1 phase. However, the difference was more prominent in the case of BPA. The G2/M:G0/G1 ratio decreased as a function of exposure time in BPA containing culture medium, thereby indicating the cell cycle dependency of BPA uptake. Such heterogeneity of boron uptake by tumor cells should be considered for microdosimetry.

Competitive uptake of porphyrin and LDL via the LDL receptor in glioma cell lines: flow cytometric analysis.

We examined the simultaneous uptake of porphyrin and (LDL) by four established cell lines of glioma and normal fibroblasts using flow cytometry (FCM). The results indicated porphyrin and LDL showed competitive conjugation with the LDL receptor. These results support the theory of the porphyrin uptake via the LDL receptor.

Cell cycle dependency of porphyrin uptake in a glioma cell line.

We used a two-color analysis system to assess the porphyrin uptake and DNA content in four established cell lines of glioma employing flow cytometry (FCM). The FCM study revealed porphyrin uptake in all cells, regardless of the phase of the cell cycle they were in. However, those in the G0/G1 phase showed moderate uptake of porphyrin and those in the G2/M phase showed a higher uptake. These results indicated the advantage of using porphyrin as the carrier of tumor targeting agents as a therapeutic strategy for malignant tumors.

A new boronated porphyrin (STA-BX909) for neutron capture therapy: an in vitro survival assay and in vivo tissue uptake study.

A new boronated porphyrin compound (STA-BX909) was developed as a possible agent for boron neutron capture therapy. The boron concentration was measured by an in vivo rat experimental brain tumor model and an in vitro cell culture study. This agent was compared to sodium borocaptate (BSH) which has been used in clinical trials of boron neutron capture therapy. In the 9L rat brain tumor model, STA-BX909 achieved a higher boron tumor/blood ratio 24 h after injection in comparison to BSH. A boron concentration study in cultured glioma cell lines (U-251, U-87, 9L) demonstrated an increased boron concentration as a function of exposure time to STA-BX909, while the boron concentration remained stable with increasing exposure time to BSH. Use of a colony forming assay with thermal neutron irradiation revealed more cytotoxicity with STA-BX909 than BSH when the same concentration of 10B was administered. We concluded that STA-BX909 may be an effective drug for use in boron neutron capture therapy and that it merits further investigation.

Glomerulocystic kidney associated with subacute necrotizing-encephalomyelopathy.

A 22-year-old man with subacute necrotizing-encephalomyelopathy (SNE; Leigh's disease) was diagnosed as having progressive renal dysfunction. The clinical diagnosis of Leigh's disease was obtained by the typical central nervous lesions, abnormalities in other organs, and increased lactate concentrations in blood and cerebrospinal fluid. We performed an open biopsy of the right kidney. Light microscopic studies of the renal specimen showed diffuse glomerulocystic kidney (GCK) with tubulointerstitial damage. Electron microscopic examination showed marked swelling and increase in the number of mitochondria of the renal tubular epithelial cells. Therefore, it is suggested that mitochondrial disease seems to play an important role in developing GCK.

Carbon dioxide reactivity of cerebral cortical and pial arteries in spontaneously hypertensive and normotensive rats--a morphometric study.

The responsiveness of cerebral arteries to the changes in arterial carbon dioxide tension (paCO2) was studied in spontaneously hypertensive rats (SHRs) and normotensive rats (NTRs). A freeze substitution method was applied for the preparation of pial and cortical arteries for morphometrical study. Hypercapnia was induced by giving 8% CO2, and hypocapnia was provided by hyperventilation. The ratios of internal (d) to external diameter (D) (d/D ratio) of both pial and cortical arteries in SHR were not different from those in NTRs during normocapnia. In hypercapnia, the ratios of pial and larger cortical arteries (D greater than or equal to 20 micron) in SHRs were 80.9 +/- 0.8% and 78.6 +/- 0.6%, respectively, being significantly smaller than 86.2 +/- 0.7% and 82.2 +/- 0.5% in NTR. In contrast, the d/D ratio of pial arteries in hypocapnia was 72.5 +/- 1.4% in SHRs, which was significantly larger than 67.5 +/- 1.4% in NTRs. The responsiveness of smaller cortical arteries (D less than 20 micron) to paCO2 was not different between SHRs and NTRs. The present results suggest that in SHRs cerebrovascular CO2 reactivity is decreased as compared to NTRs, especially in pial and larger cortical arteries.

Anti-idiotype monoclonal antibodies against anti-microcystin antibody and their use in enzyme immunoassay.

Microcystins (MCs), a group of heptapeptide hepatotoxins produced by cyanobacteria, are suspected as tumor-promoter contaminants of environmental water. We have previously developed an enzyme-linked immunosorbent assay (ELISA) for MCs based on an anti-MC MAb (MAb-mc). We describe here the production of anti-idiotype MAbs (MAb-ids) which react with MAb-mc and their use in a new ELISA for MCs. For the production of MAb-id, hybridoma cells were generated from mice immunized with MAb-mc. Two MAbs were selected for their ability to inhibit the binding of MAb-mc to microcystin-LR (MCLR)-bovine serum albumin conjugate in ELISA. The one with the higher inhibitory activity, designated Id7 (IgG1, kappa), was further characterized. ELISA and immunoprecipitation analysis revealed that Id7 specifically bound to MAb-mc but not to control IgG1, and the binding was inhibited by free MCLR. Therefore, Id7 is a MAb-id to MAb-mc and potentially possesses the structural image of MCLR. To establish MAb-id based ELISA, Id7 was tested for use in three types of competitive ELISA for MCs. The best format enabled reliable measurements of MCLR in the range of 100-1000 pg/ml with a coefficient of variation of less than 3%. In addition, microcystin-RR and microcystin-YR, principal MCs found in environmental water, were cross-reacted well (67-111% of MCLR) in the ELISA although 6(Z)-MCLR, a minor component, was less reactive (7% of MCLR). A comparative study of the MAb-id based ELISA with previously established MAb-mc based ELISA revealed good correlation (n = 14, r = 0.97) between the two methods for measurements of MCs content in freshwater samples. Thus, developed MAb-id based ELISA is an useful alternative for environmental monitoring of MCs.

Manganese-metalloporphyrin (ATN-10) as a tumor-localizing agent: magnetic resonance imaging and inductively coupled plasma atomic emission spectroscopy study with experimental brain tumors.

OBJECTIVE: We examined whether selective tumor accumulation of a novel manganese-metalloporphyrin (ATN-10) occurs in Fisher rats bearing intracerebral 9L gliomas. METHODS: After intravenous administration of ATN-10, magnetic resonance imaging of brains with tumors or nontumoral vasogenic brain edema was performed. Tissue manganese concentrations were measured by inductively coupled plasma atomic emission spectroscopy until 48 hours after administration of ATN-10, to evaluate its uptake in tumor, normal brain, and peritumoral brain tissue. RESULTS: In magnetic resonance imaging scans, early enhancement was observed in both tumor tissue and regions of nontumoral vasogenic brain edema at 5 minutes after ATN-10 administration. However, delayed enhancement was noted only in tumor tissue, at 24 hours after intravenous injection of ATN-10. Comparison of rat brain specimens and 24-hour magnetic resonance imaging scans revealed that only the viable portions of tumors were enhanced with ATN-10; necrotic regions and areas of peritumoral brain tissue and nontumoral vasogenic edema were not. Significantly greater uptake of ATN-10 was found in tumor samples, compared with normal and peritumoral brain tissue, at 24 hours. A high tumor/normal brain tissue ratio (10.4) was achieved at 24 hours. CONCLUSION: ATN-10, a manganese-metalloporphyrin, is a potentially useful tumor-localizing agent that accumulates and is preferentially retained in viable tumor tissue.

A new spontaneous animal model of NIDDM without obesity in the musk shrew.

The EDS (early-onset diabetes in suncus) colony has been developed as a new closed breeding colony of the musk shrew (Suncus murinus, Insectivora) exhibiting a high incidence of spontaneous diabetes mellitus. We investigated the characteristic features of diabetic shrews in this colony. All diabetic shrews are characterized by glycosuria (Tes-tape value > or = 3+), hyperglycemia (23.3 +/- 0.8 mmol/l) and polyuria, and they were affected by the age of 3 months. Cumulative incidence (64.1% in males and 27.8% in females) was kept intact after the age of 3 months. The growth pattern of diabetic shrews was similar to that of non-diabetic shrews, and obesity was not consistent in diabetic shrews. The intraperioneal glucose tolerance test revealed both impaired glucose tolerance and impaired insulin secretion in diabetic shrews. Insulin sensitivity of diabetic shrews decreased in the intraperioneal insulin tolerance test. Neither severe hypertrophy nor lymphocytic infiltration was observed in pancreatic islets of diabetic shrews. These facts suggested that diabetic shrews in the EDS colony should be classified as early-onset non-insulin dependent diabetes mellitus (NIDDM) without obesity. Early-onset of severe hyperglycemia with impaired glucose tolerance is a distinctive character compared with other non-obese NIDDM models in rodents. We concluded that the diabetic shrews in the EDS colony are a new animal model of human NIDDM without obesity.

Metformin ameliorates treatment of obese type 2 diabetic patients with mental retardation; its effects on eating behavior and serum leptin levels.

The metabolic effects of a biguanide, metformin, on glycemic control and eating behavior were investigated in 16 type 2 diabetic subjects with mental retardation who were habitual overeaters and had difficulty in controlling their appetites. The subjects (n = 16) received metformin (750 mg/day) for 6 months and body weight, body mass index (BMI) were measured monthly. They had repetitive metabolic and hormonal studies. Their eating behavior was analyzed by questionnaires given by their guardians before and after treatment. Metformin treatment significantly reduced their body weights (p < 0.01), body mass index (BMI) (p < 0.01), the levels of HbA1c (p < 0.001), fasting blood glucose (FBG) (p < 0.05), serum insulin (p < 0.05), C-peptide (p < 0.01), triglyceride (p < 0.01), and total cholesterol (p < 0.05). Insulin resistance index (FBG (mg/dl) x serum insulin levels ( micro U/ml) x 1/405) was significantly reduced after 1-month treatment. The serum leptin levels were significantly decreased after 4 month's treatment and thereafter (p < 0.05). Analysis of the questionnaires before and after treatment showed that the daily intake of regular and additional foods significantly decreased after treatment (p < 0.01 and p < 0.001, respectively) with improvements of eating behavior. We conclude that metformin may have beneficial effects not only to control glycemia but also to correct eating behavior in obese type 2 diabetic patients with the difficulty in controlling their appetites. The improvement was related to the reduction of insulin resistance and serum leptin levels.

Unified model for the corneal permeability of related and diverse compounds with respect to their physicochemical properties.

Corneal permeability data taken from the literature were analyzed for possible quantitative relationships with physicochemical properties. Although a parabolic relationship was obtained with good correlation between lipophilicity, as expressed by the 1-octanol-water partition coefficients, log Poctanol (or the distribution coefficients, log D for ionizable compounds), and the permeability in individual analyses of compound classes such as beta-adrenoceptor blockers and steroids, the correlation was reduced when taken together. However, delta log P (i.e., log Poctanol-log Palkane) correlated inversely with the combined permeability data for beta-blockers and steroids and played a key role as a unifying variable. To a lesser extent, lipophilicity itself also contributes positively to corneal permeation. Even with the addition of miscellaneous compounds such as methanol and ibuprofen, the delta log P and lipophilicity terms were still significant. However, small molecules were likely to be underestimated, which is consistent with penetration via another pathway besides that governed by delta log P and lipophilicity.

The kidney disease of Crow-Fukase (POEMS) syndrome: a clinico-pathological study of four cases.

We studied four cases of Crow-Fukase syndrome with renal dysfunction. Kidney specimens obtained by needle biopsy showed glomerular lesions resembling those seen in conditions characterized by microangiopathy. Common glomerular findings by light microscopy were mesangial expansion and narrowing of the capillary lumina. An enlarged subendothelial space and mesangial area with deposition of amorphous material as well as swelling and vacuolization of endothelial cells were observed by electron microscopy. In an active phase, severe mesangial edema and segmental mesangiolysis, and in a late stage, mesangial cell interposition and sclerosis were seen. Tests by immunofluorescence microscopy for the presence of immunoglobulins A, M, G, lambda and kappa light chains, C3, and C4 were negative. Decay accelerating factor was found in glomeruli and in the vascular pole. Other findings included lymph node angiosclerosis, peripheral nerve microangiopathy and hemangioma formation with endothelial cell proliferation. These observations suggest that chronic endothelial injury constitutes the basic pathology of Crow-Fukase syndrome. Hemodialysis was required to manage anasarca in three of the patients although serum creatinine levels were below 5.0 mg/dl. Urinalysis revealed mild abnormalities and did not reflect the severity of the glomerular lesion. Corticosteroids given to three of the patients were effective in controlling fever and the lymphadenopathy; in two cases the corticosteroids induced a recovery of renal function. Thus Crow-Fukase syndrome may be due to chronic endothelial injury; the clinical symptoms and renal involvement respond to corticosteroid therapy.