Role of Heavy Meromyosin in Heat‐Induced Gelation in Low Ionic Strength Solution Containing l‐Histidine

The gelation of myosin has a very important role in meat products. We have already shown that myosin in low ionic strength solution containing l ‐histidine forms a transparent gel after heating. To clarify the mechanism of this unique gelation, we investigated the changes in the nature of myosin subfragments during heating in solutions with low and high ionic strengths with and without l ‐histidine. The hydrophobicity of myosin and heavy meromyosin (HMM) in low ionic strength solution containing l ‐histidine was lower than in high ionic strength solution. The SH contents of myosin and HMM in low ionic strength solution containing l ‐histidine did not change during the heating process, whereas in high ionic strength solution they decreased slightly. The heat‐induced globular masses of HMM in low ionic strength solution containing l ‐histidine were smaller than those in high ionic strength solution. These findings suggested that the polymerization of HMM molecules by heating was suppressed in low ionic strength solution containing l ‐histidine, resulting in formation of the unique gel.     

Quantitative measurement of hard x-ray spectra for high intensity laser produced plasma

X-ray line spectra ranging from 17 to 77 keV were quantitatively measured with a Laue spectrometer, composed of a cylindrically curved crystal and a detector. Either a visible CCD detector coupled with a CsI phosphor screen or an imaging plate can be chosen, depending on the signal intensities and exposure times. The absolute sensitivity of the spectrometer system was calibrated using pre-characterized laser-produced x-ray sources and radioisotopes. The integrated reflectivity for the crystal is in good agreement with predictions by an open code for x-ray diffraction. The energy transfer efficiency from incident laser beams to hot electrons, as the energy transfer agency for specific x-ray line emissions, is derived as a consequence of this work.     

Bronchial mucoid impaction due to the monokaryotic mycelium of Schizophyllum commune

PURPOSE: A prospective trial was done to test the efficacy of antimicrobial prophylaxis in patients undergoing transurethral surgery. MATERIALS AND METHODS: A total of 75 adults with preoperatively sterile urine was randomized to receive either 400 mg. oral fleroxacin once daily or placebo as long as the catheter was in place. Urine cultures were obtained preoperatively and after removal of the catheter just before hospital discharge. Growth of 10(4)/ml. or more bacteria was considered a positive urine culture. RESULTS: Postoperative urinary tract infection rates were significantly lower in the fleroxacin group (3%) than in the placebo group (23%). Our study demonstrated the benefit of antimicrobial prophylaxis in preventing urinary tract infection after transurethral surgery, including resection of the prostate, in patients with sterile urine. CONCLUSIONS: The oral administration of 1 daily tablet of fleroxacin for the duration of catheterization is a safe, efficacious and clinically feasible regimen.     

Purification and characterization of ouabain-binding protein in human plasma

Ouabainlike factors are thought to be a kind of important modulators of salt and water metabolism in essential hypertension. We purified the binding-protein of ouabain (OBP) from human plasma. The amino-terminal sequence of OBP from human plasma, (NH2-TLGQPREPQVYTLPPXREEM-), indicated that OBP is the carboxy-terminal fragment (14.4 kDa by SDS-PAGE) from T218 of IgG2 heavy chain and from A221 of the IgG1 heavy chain constant region. Moreover, plasmin-cleaved Fc fragment (pFc) of IgG possessed the ouabain-binding activity by the gel-filtration method of pFc and authentic ouabain mixture, whereas neither intact, aggregate, nor papain-cleaved Fc fragment did. The amino-terminal sequence of pFc was NH2-THTXPPXPAPELLGGPXVFL-, and this sequence corresponded to the T105 to L125 fragment of the IgG1 heavy chain constant region. The growth of cultured THP-1 cells were arrested in the dose-dependent manner by ouabain, which was inhibited by the addition of 20 microg/mL of pFc. These results suggested that plasmin-cleaved Fc of human IgG is one of the binding protein of ouabain/ouabainlike factor(s) in human plasma.     

No involvement of APC gene mutations in ulcerative colitis-associated rat colon carcinogenesis induced by 1-hydroxyanthraquinone and methylazoxymethanol acetate

In 1992, 1531 women aging 25-45 years from 5 urban and rural regions were interviewed about infertility and subfecundity within the German part of a study by the European community. 1248 of them had a positive reproductive history with 3018 pregnancies. 400 (= 13.25%) occurred during contraception. This affected 296 women (= 19.6% of all women). Smoking seems to have a promotion effect. The risk of ectopic pregnancies seems to be higher in contraceptive users. The highest fetal loss was found in women using an IUD. There were no differences in the course and outcome of pregnancy between users and nonusers of contraceptives. About 40% of the women in the corresponding group reported an irregular application of the contraceptive technique.     

Enhanced renal toxicity by inorganic mercury in metallothionein-null mice

To elucidate a protective role of metallothionein (MT) in the manifestation of inorganic mercury toxicity, we studied the susceptibility of MT-null mice to the renal toxicity of mercuric chloride. Because the MT-null (J) mice are a genetic background of 129/Sv strain, the 129/Sv mice were used as wild-type controls. Nine-week-old male MT-null (J) and 129/Sv mice were given subcutaneous injections of mercuric chloride at doses of 10 to 40 micromol/kg. The basal MT level in the kidney of MT-null (J) mice was undetectable (<0.2 microg/g of tissue) and approximately 2.5 microg/g of tissue in 129/Sv mice. The sensitivity to the renal toxicity of mercuric chloride was markedly enhanced in the MT-null (J) mice compared with the 129/Sv mice. The renal mercury level was similar for the MT-null (J) and 129/Sv mice at 4 hr after the injection of mercuric chloride (20 micromol/kg) but became significantly lower in MT-null (J) mice than in 129/Sv mice at 24 and 72 hr. Based on the present results, we conclude that MT is an important protective factor against the renal toxicity caused by inorganic mercury and that it may play a major role in the retention of mercury in the kidney.     

Diurnal variation in serum remnant-like lipoproteins, platelet aggregation and fibrinolysis in healthy volunteers

The linkage of cobalamin and folate deficiency to psychiatric illness has been studied and debated since these vitamins were first discovered in the 1940s. The clinical relevance of these deficiencies remains the subject of investigation and scholarly discussion. This article reviews case reports and studies derived from a MEDLINE search for English-language articles related to folate, cobalamin, and psychiatric illness. Emphasis is given to clinical research and recent developments. Preclinical evidence for direct effects of folate and cobalamin on brain functioning is compelling, and numerous associations of their deficiencies to psychiatric illness are evident. These vitamin deficiencies may typically present initially with psychiatric symptoms, but any direct causal relationship to specific neuropsychiatric illnesses are not well defined. The relationship of these vitamins in dementia is significant, but they may only rarely be a cause of truly reversible dementia. Folate deficiency appears most tightly connected with depressive disorders, and cobalamin deficiency with psychosis. Contrary to intuition, vitamin deficiencies appear to occur infrequently with eating disorders. Other diagnoses have been investigated much less extensively. The diagnosis and management of these deficiencies in the context of neuropsychiatric illness is still a matter of discussion. The quality of clinical research in this area is improving, but there are many unanswered questions that affect clinical practice. Clinicians should remain vigilant to the possibility of deficiencies of folate and cobalamin in diverse psychiatric populations. Normal hematological indices do not rule out the deficiencies. Further study is needed to refine the detection and clinical management of these vitamin deficiencies in psychiatric populations.     

Continuous versus bilevel positive airway pressure in a patient with idiopathic central sleep apnea

A 57-yr-old man with idiopathic central apnea is reported. He presented at our hospital complaining of excessive daytime sleepiness. Polysomnography, including esophageal pressure monitoring, confirmed central sleep apnea with an apnea index of 27/h. He had mild non-insulin-dependent diabetes mellitus (NIDDM) but no signs of diabetic neuropathy or other background diseases. The ventilatory responses to hypoxia and hypercapnia tested while he was awake indicated increased respiratory chemosensitivity. We applied nasal continuous positive airway pressure (CPAP) and bilevel positive airway pressure (BPAP) in an attempt to compare the possible difference in therapeutic efficacy. Although nasal CPAP completely reversed central apnea, nasal BPAP adversely affected both apnea length and frequency in an applied pressure-dependent manner. Arterial blood gas analyses while he was being treated indicted alveolar hypoventilation with CPAP and hyperventilation with BPAP. Additionally, administration of a mixed gas containing 5% CO2 through a face mask had a significant effect on the disappearance of central apnea in this patient. These findings support the theory that the arterial PCO2 level is critical in generating idiopathic central apnea and that nasal CPAP therapy may be effective in eliminating central apnea by raising the PaCO2.     

Instrumentation for dual-probe scanning near-field optical microscopy

To investigate local carrier motions, we developed a dual-probe scanning near-field optical microscope (SNOM) with two fiber probes where one is for photoexcitation and the other is for light collection. This instrumentation is based on two important techniques: the design of probe structures and distance control between the sample surface and the two probes. A finite-difference time-domain method numerically analyzed and optimized the design for high efficiency photoexcitation and light collection, while a dual band modulation realized distance control. Real time detection of the oscillations of the probe tips using different frequencies independently controls the distance between the probe tip and the sample surface as well as the distance between the two probes. Thus, the collection probe can be scanned around an illumination probe without destroying the probe tips. To demonstrate our SNOM, we performed photoluminescence spectroscopy under the dual-probe configuration and observed carrier motions in an InGaN quantum well.     

Studies on ion-exchange membranes. XXXII. Heterogeneity in ion-exchange membranes

Twelve kinds of cation-exchange membranes were treated with hydrogen peroxide. Some of them (Selemion CMV, Nepton CR-61, Scrion C-100, SAM-1) were completely destroyed. Heterogeneity is believed to be present in that part of their chemical structures that is decomposable by the treatment. The other membranes were converted into porous membranes by the decomposition of the resinous part. Water permeabilities and electric resistances of the porous membranes were examined to evaluate the pore radius. It was concluded that the “paste method” membranes have a heterogeneity or localized distribution of the resinous part under 50 mμ. The “paste method” membranes seemed to resemble the “graft method” membranes in chemical structure and to be much different from the mosaic-type membranes such as Permaplex and MC-3142. These results were also supported by extraction of the membranes with appropriate solvents and observation by electron microscopy.