Chitinase expression in parotid glands of non-obese diabetic mice.

OBJECTIVE: This investigation was a basal study that used a mouse model of xerostomia to identify protein biomarkers of xerostomia in saliva. We identified genes expressed differently in parotid glands from non-obese diabetic mice with diabetes and those from control mice; subsequently, we investigated expression of the proteins encoded by these genes in parotid glands and saliva. MATERIALS AND METHODS: DNA microarray and real-time PCR analyses were performed to detect differences between NOD/ShiJcl and C57BL/6JJcl (control) female mice in gene expression from parotid glands or parotid acinar cells. Subsequently, protein expression was assessed using immunoblotting and immunohistochemistry. Similarly, enzyme activity in saliva was assessed using zymography. RESULTS: Based on gene expression analyses, Chia expression was higher in diabetic mice than non-diabetic mice and control mice; similarly, expression of chitinase, the protein encoded by Chia, was higher in diabetic mice. Saliva from NOD/ShiJcl mice had more chitinase than saliva from control mice. CONCLUSIONS: Chitinase was highly expressed in parotid acinar cells from diabetic mice compared with non-diabetic and control mice. Increased chitinase expression and enzyme activity may characterize the autoimmune diabetes in mice; however, further investigation is required to assess its use as a biomarker of xerostomia in humans.

Hopes and fears regarding care robots: Content analysis of newspapers in East Asia and Western Europe, 2001-2020.

Background: As a type of welfare technology, care robotics is now widely seen as a potential aide to rehabilitation, increasing independence and enhancing the wellbeing of people with disabilities and older adults. Research into and development of care robots have both been vigorously promoted in North America, Europe and Asia, and the competition for technological advancement in robotics is becoming fierce. AI ethics and policy guidelines are being established. However, there are still differences in attitudes and perceptions, as well as national policies regarding this type of welfare technology. Moreover, despite the anticipated usefulness, it is believed that progress has been slow in the diffusion of care robots. Purpose: In order to explore how public discourses support technological innovation, such as care robots, while preparing society for potential risks and impact, we sought to ascertain whether public discourse on care robots varies from region to region. For example, what are the hopes and promises associated with care robots and what are the concerns? Methods: To address these questions, this article explored how care robots have been portrayed in five major broadsheet newspapers in five jurisdictions in Asia and Europe (France, Great Britain, Hong Kong SAR, Ireland and Japan). We obtained 545 articles for the period between January 2001 and September 2020, more than half of which originated in Japan. A thematic analysis was conducted of these articles written in four languages (Chinese, English, French and Japanese). Results: Positive and negative narratives were teased out, alongside other key prominent themes identified, such as Japan as the land of robots, the pandemic, and the impact of robots on the economy. As the number of robot-related articles grew from the year 2012 onwards, narratives became more nuanced in European newspapers, but not in Asian ones. Furthermore, recent articles began to address the social and relational impact of care robots, while providing concrete examples of improvements in the quality of life for users. Further careful examination will be necessary in the future in order to establish the impact of robotics use in rehabilitation for people with disabilities, older adults, their carers and society at large.

Late referrals to home palliative care service affecting death at home in advanced cancer patients in Japan: a nationwide survey.

BACKGROUND: To identify factors influencing place of death among home palliative care patients with advanced cancer, focusing on the timing of referrals from hospital to home care settings. METHODS: A cross-sectional nationwide questionnaire survey was conducted on home palliative care patients at 1000 randomly selected home care agencies in Japan. A total of 568 responses were analyzed (effective response rate, 69%). RESULTS: Multivariate logistic regression analysis revealed that (i) predischarge health care supports in hospital (e.g. early referral 8 days or more before discharge; clear explanation by hospital staffs to patients and families regarding discharge to live and die at home) and (ii) postdischarge health care supports after transferring home care (e.g. signing a 24-h support insurance contract of network between primary physician and nurse as a home palliative care team; primary nurse consultation with primary physician >3 times during the first week after discharge) have an effect on place of death among home palliative care patients. CONCLUSION: An early and carefully coordinated referral support system for smooth discharge by hospital staffs as well as intensive and highly qualified support just after discharge by the home care team would help to increase the number of patients who could die at home.

Hydrogen bond network of cytochrome P-450cam: a network connecting the heme group with helix K.

During investigations of the structural character of a mutant P-450cam where Glu-286 is replaced with lysine, we obtained evidence of a hydrogen bond network between helix K and the heme group via helix L of P-450cam. This mutant protein loses the ability to maintain the heme group in a proper position, possibly due to a break in the hydrogen bond network.

Essential role of the Arg112 residue of cytochrome P450cam for electron transfer from reduced putidaredoxin.

Cytochrome P450cam (CYP101) of Pseudomonas putida PpG1 in which Arg112 is substituted by Cys was isolated by in vitro random mutagenesis of the camC gene DNA coding for P450cam. The absorption spectra of the purified mutant enzyme were similar to those of the wild type enzyme, but its substrate-dependent NADH oxidation activity in the presence of putidaredoxin (Pd) and putidaredoxin reductase (PdR) was extremely low. The rate constant of electron transfer from reduced Pd to the heme of the mutant P450cam, measured on an anaerobic stopped flow apparatus, was 1/400 of that of the wild type enzyme and the dissociation constant of the mutant P450cam for oxidized Pd was several fold higher than that of the wild type enzyme. A considerable decrease in mid-point potential of the mutant enzyme was also noted. We conclude that Arg112, which is located on the surface of the P450cam molecule and hydrogen-bonded to one of the heme propionate chains, plays an essential role in the electron transfer from Pd.

Photoreactive nitrile hydratase: the photoreaction site is located on the alpha subunit.

Nitrile hydratase (NHase) from Rhodococcus sp. N-771 exists in active and inactive forms. The inactive NHase is immediately activated by light irradiation and changes to the active form. To characterize the photoreactive center, the inactive NHase was denatured by 6 M urea, and two kinds of subunits (alpha and beta) were separated and purified by anion-exchange chromatography. In a manner similar to the native NHase, the isolated alpha subunit showed two absorption peaks at 280 and 370 nm, which were diminished by light irradiation. However, irradiation failed to elicit the appearance of absorption peaks at around 400 nm and at 710 nm, which were characteristic of the activated enzyme. The beta subunit seemed not to possess any photoreactive chromophore because its absorption spectrum was not altered by light irradiation. Neither of the subunits showed NHase activity before and after light irradiation, but the inactive NHase was reconstituted by incubating the two subunits together in the dark at 4 degrees C for 1 h. Light irradiation of the beta subunit did not affect subsequent complex formation or NHase activity. However, the irradiated alpha subunit could not assemble with the beta subunit, and no activity was recovered. These results demonstrate that the chromophore(s) responsible for the photoactivation of NHase are entirely located on the alpha subunit, and imply that light irradiation induces conformational change of the alpha subunit.

Functional expression of nitrile hydratase in Escherichia coli: requirement of a nitrile hydratase activator and post-translational modification of a ligand cysteine.

The nitrile hydratase (NHase) from Rhodococcus sp. N-771 is a photoreactive enzyme that is inactivated on nitrosylation of the non-heme iron center and activated on photo-dissociation of nitric oxide (NO). The nitrile hydratase operon consists of six genes encoding NHase regulator 2, NHase regulator 1, amidase, NHase alpha subunit, NHase beta subunit and NHase activator. We overproduced the NHase in Escherichia coli using a T7 expression system. The NHase was functionally expressed in E. coli only when the NHase activator encoded downstream of the beta subunit gene was co-expressed and the transformant was grown at 30 degrees C or less. A ligand cysteine, alphaCys112, of the recombinant NHase was also post-translationally modified to a cysteine-sulfinic acid similar to for the native NHase. Although another modification of alphaCys114 could not be identified because of the instability under acidic conditions, the recombinant NHase could be reversibly inactivated by nitric oxide.

Blockade of angiotensin receptors in the anterior hypothalamic preoptic area lowers blood pressure in DOCA-salt hypertensive rats.

It has been established that deoxycorticosterone acetate (DOCA)-salt hypertensive rats have an overactive brain angiotensin-system. The purpose of the present study was to identify the brain sites showing enhanced angiotensin-system activity responsible for the pathogenesis of hypertension in DOCA-salt hypertensive rats. The angiotensin receptor antagonist, losartan, was injected into brain ventricles or into tissues around the rostral parts of the third ventricle in conscious DOCA-salt hypertensive rats. Losartan (1 microg) injection into the lateral ventricle or into the rostral parts of the third ventricle produced a depressor response, whereas the agent did not affect blood pressure when injected into the caudal parts of the third ventricle or into the fourth ventricle. Losartan (0.1 microg) injection into the anterior hypothalamic preoptic area, anterior (AHA) produced a depressor response. Angiotensin II (0.1-1 ng) injection into the AHA produced a pressor response in sham-operated and DOCA-salt hypertensive rats, and the pressor response to angiotensin II (1 ng) was greater in DOCA-salt hypertensive rats than that in sham-operated rats. Release of angiotensin peptides in the AHA was greater in DOCA-salt hypertensive rats than that in sham-operated rats. These findings suggest that the angiotensin-system in the AHA is enhanced, and that this enhancement is involved in the maintenance of hypertension in DOCA-salt hypertensive rats. Both increased pressor reactivity to angiotensin II and increased release of angiotensin peptides in the AHA appear to be related to this enhancement of the angiotensin-system in DOCA-salt hypertensive rats.

An angiotensin system in the anterior hypothalamic area anterior is involved in the maintenance of hypertension in spontaneously hypertensive rats.

An overactive brain renin-angiotensin system is one of the factors contributing to the pathogenesis of hypertension in spontaneously hypertensive rats (SHR). We examined brain sites where enhanced activity of an angiotensin system is responsible for the pathogenesis of hypertension in SHR. The angiotensin receptor antagonist, losartan was injected into tissues around rostral parts of the third ventricle in conscious rats. Losartan (0.22 nmol) injected into the anterior hypothalamic area, anterior (AHA) produced a depressor response in SHR but not in Wistar Kyoto rats (WKY). Angiotensin II (0.091-0.91 pmol) injected into the AHA produced a pressor response in both WKY and SHR, and the pressor response to angiotensin II was greater in SHR than that of WKY. Carbachol (3 pmol) injected into the AHA also produced a pressor response in WKY and SHR, and the pressor response to carbachol was almost the same in both strains of rats. Release of angiotensin peptides in the AHA was greater in SHR than that of WKY. These findings suggest that an angiotensin system in the AHA is enhanced and this enhancement of angiotensin system is involved in the maintenance of hypertension in SHR. Both increased pressor reactivity to angiotensin II and increased release of angiotensin peptides in the AHA appear to be related to this enhancement of angiotensin system in SHR.

Fe-type nitrile hydratase.

The characteristic features of Fe-type nitrile hydratase (NHase) from Rhodococcus sp. N-771 are described. Through the biochemical analyses, we have found that nitric oxide (NO) regulates the photoreactivity of this enzyme by association with the non-heme iron center and photoinduced dissociation from it. The regulation is realized by a unique structure of the catalytic non-heme iron center composed of post-translationally modified cysteine-sulfinic (Cys-SO2H) and -sulfenic acids (Cys-SOH). To understand the biogenic mechanism and the functional role of these modifications, we constructed an over-expression system of whole NHase and individual subunits in Escherichia coli. The results of the studies on several recombinant NHases have shown that the Cys-SO2H oxidation of alphaC112 is indispensable for the catalytic activity of Fe-type NHase.

Arginine 56 mutation in the beta subunit of nitrile hydratase: importance of hydrogen bonding to the non-heme iron center.

Arginine 56 in the beta subunit (betaArg56) of the iron-containing nitrile hydratase (NHase), one of the strongly conserved residues within the NHase family, is known to form hydrogen bonds to the sulfinyl (-SO2H) and sulfenyl (-SOH) groups of the post-translationally modified cysteine residues in the catalytic center. BetaArg56 was substituted by tyrosine, glutamate or lysine, respectively, and the respective mutant enzymes generated by reconstitution were characterized. The betaR56K mutant complex exhibited about 1% of the enzymatic activity of native NHase, while the others were totally inactive. The kinetic analysis of the betaR56K mutant complex exhibited a drastic decrease in turnover number and decreases in kinetic constants for substrate and inhibitors as compared to the native NHase. Changes in UV-visible absorption and light-induced Fourier transform infrared difference spectra suggest that betaArg56 is involved in the positioning of the -SO2H and -SOH groups of the modified Cys residues in the catalytic center so as to fine tune the electronic state of the iron center suitable for catalysis. Thus, betaArg56 is essential for catalysis.

Studies on the excretion of ascorbic acid 2-sulfate and total vitamin C into human urine after oral administration of ascorbic acid 2-sulfate.

The excretion of AsS and total vitamin C into urine after oral administration of AsS to humans was investigated. When 10 mmol of AsS was administered to the subjects, the excretion of AsS into urine continued for 60 hr in males and 48 hr in females. The average amount excreted per hour was less than 5 mg. These results differed from those for AsA and DAsA orally administered to humans. The determination of vitamin C after oral administration of AsS to the subjects consisting of ten males and six females showed no vitamin C effect in humans, similarly to the case with the guinea pig and the rhesus monkey.

Studies on the ascorbic acid 2-sulfate biosynthesis in rat.

The possible biosynthesis of ascorbic acid 2-sulfate (AsS) in rat was investigated. A in vivo test was conducted according to Mumma and Mohamram. 10 mumoles ascorbic acid (AsA) and 25 mu Ci35SO4(2-) were injected intraperitoneally into rats once a day for four days. 24 hours after the final administration, the animals were sacrificed and the liver, kidneys and urine were collected. The result did not confirm the biosynthesis of AsS under the test conditions, though there appeared the possibility of the biosynthesis of a trace amount of AsS too small to permit detection.

Synthesis and antiscorbutic activity of vitamin C analogue: L-threo-hex-2-enaro-1,4-lactone ethyl ester in the guinea pig.

L-threo-hex-2-enaro-1,4-lactone ethyl ester (II) was synthesized by the modified Fisher's esterification and its sodium salt was obtained almost quantitatively. Confirmation of the compound was made by elementary analysis, as well as IR, UV, MS and NMR spectra. The antiscorbutic activity was compared to that of ascorbic acid and the result showed that (II) did not have Vitamin C activity. The results of this investigation indicate that a close relationship exists between the chemical structure of the C-6 position of ascorbic acid analogues and the development of vitamin C activity.

Antiscorbutic activity of 6-bromo-6-deoxy-L-ascorbic acid in the guinea pig.

The antiscorbutic activity of 6-bromo-6-deoxy-L-ascorbic acid (I) in guinea pigs was compared to that of ascorbic acid (AsA). The growth test results in guinea pigs did not show any significant difference between the body weight increase in the respective 2 groups given compound (I) and that in the group given AsA. Scorbutic guinea pigs were found to completely recover from the disease after administration of the compound (I). There were no significant differences in the plasma alkaline phosphatase activity and the hydroxyproline content in the tibia between the group given compound (I) and that given AsA. The total vitamin C contents in the various tissues were similar in the 2 groups given compound (I) and the C-deficient group but they were lower than the levels for the group given AsA. It was shown that antiscorbutic activity was characteristic of compound (I) and it was almost equal to the effect of AsA.

Preoperative irradiation of a huge cavernous hemangioma in the middle cranial fossa--case report.

A 52-year-old female with a huge cavernous hemangioma in the middle cranial fossa received preoperative radiation therapy to reduce intraoperative bleeding from the tumor. Following irradiation the tumor decreased in size and was subtotally removed with ease. Preoperative irradiation is highly beneficial in such cases.

Subfascial temporalis dissection preserving the facial nerve in pterional craniotomy--technical note.

The subfascial temporalis dissection and reconstruction of the temporalis muscle for pterional craniotomy are described. These procedures preserve the frontotemporal branch of the facial nerve and increase exposure along the sphenoid ridge. A good cosmetic appearance and good temporalis muscle function are achieved postoperatively.

The self-choice elaboration effects on incidental memory of Japanese historical facts.

The subjects performed an orienting task involving 3 conditions, followed by unexpected tests which included free recall, name-matching and name-selec tion. Conditions were designed to force self-generated elaboration, self-choice elaboration, and experimenter-provided elaboration. In the self-generated elaboration condition, subjects were presented target sentences, e.g., Nobunaga ODA burned down ENRYAKUJI Temple, and asked to answer an elaborative interrogation, e.g., Why did Nobunaga ODA burn down ENRYAKUJI Temple? about each sentence. In the self-choice elaboration condition, subjects selected one of the alternative answers to an elaborative interrogation about each sentence. In the experimenter provided elaboration condition, subjects were presented an answer which they rated for congruity as the correct answer to the elaborative interrogation. In the free recall test, self generated elaboration led to better performance than the other two conditions for which no difference was observed. However, in the name-matching and name-selection tests, scores were better for self choice elaboration and self-generated elaboration than for experimenter-provided elaboration. These results were interpreted as demonstrating that self choice elaboration, in addition to self-generated elaboration, led to effective encoding in memory.

[Surgical treatment of aged patients with ruptured cerebral aneurysm; evaluation of the operations performed without using retractors].

Sixteen patients over 70 years of age with ruptured cerebral aneurysms in the anterior circulation were surgically treated via the pterional approach. Self-retaining brain retractors (SRBRs) were used in seven patients (Group A), but not in nine other patients (Group B). On admission there were no significant differences between the groups in terms of the neurological grading of Hunt & Kosnik or the CT grading of Fisher. The timing of the operation was decided on the basis of the neurological grading of Hunt & Kosnik and the systemic complications present in each case. Early operation (within 2 days) was performed in 10 cases (5 cases in each group), whereas delayed operation (after 15 days) was carried out in 6 cases (Group A: 2 cases; Group B: 4 cases). Symptomatic vasospasm occurred in 43% of Group A and in 33% of Group B. Postoperative CT scans showed new or aggravated brain edema in the fronto-temporal region (the site of craniotomy) in 3 Group A cases, but not in any Group B cases. By means of technetium-99m-labeled hexamethyl-propyleneamine oxime single photon emission computed tomography (SPECT) the regional cerebral blood flow (CBF) in the fronto-temporal region of the operated side was studied in 6 patients (3 cases in each group) one day after and three months after the operation. One day after the operation, the regional CBF in the fronto-temporal region had decreased in the three Group A cases, but no changes were observed in the three Group B cases. Three months after the operation the regional CBF impairment had improved in 2 of the Group A cases.(ABSTRACT TRUNCATED AT 250 WORDS)

[Treatment of symptomatic vasospasm with GIK (glucose-insulin-potassium) infusion].

GIK (glucose-insulin-potassium) solution has been administered to myocardial infarction patients as a polarizing therapy, but the effects of GIK administration on vasospasm after subarachnoid hemorrhage have never been reported. We used GIK solution to treat 7 cases of symptomatic vasospasm with congestive heart failure due to hypervolemia-hypertensive treatment. The GIK solution, composed of 200cc of 50% glucose solution, 250cc of water, 40 mEq of KCl, and 20 units of actrapid insulin, was administered continuously through a central venous catheter. The GIK therapy improved congestive heart failure following elevation of cardiac output in 7 cases, and simultaneously stabilized the serum glucose level within the range of 88-175 mg/dl. After GIK administration, remarkable improvement in the consciousness level was achieved in all cases, and cerebral infarction due to vasospasm appeared in only one case in spite of severe subarachnoid hemorrhage. It is thought that GIK therapy will be effective in the treatment of symptomatic vasospasm with congestive heart failure through the normalization of hemodynamics, the improvement of hyperglycemia and protection against cerebral ischemia.