Impact of medical students' socioeconomic backgrounds on medical school application, admission and migration in Japan: a web-based survey

OBJECTIVES

The aim of this study was to clarify and compare the socioeconomic backgrounds of medical students with those of other health professions and non-health faculty students in an era of increasing inequity in Japanese society.

DESIGN

This was a quantitative nationwide study. Data were collected by a cross-sectional web-based anonymous questionnaire.

SETTING

Data from years 3 and 4 medical, health professions and non-health faculty students across Japan were collected in 2021.

PARTICIPANTS

Participants were 1991 students from medical schools, 224 from dental, 419 from pharmacy, 326 from nursing, 144 from other health professions and 207 from non-health faculties.

RESULTS

The proportion of high-income families (>18 million yen: ca. US$140 000) among medical students was 25.6%, higher than that of pharmacy (8.7%) and nursing students (4.1%) (p<0.01). One-third of medical students had a physician parent, more common than in non-medical students (p<0.01). Students who only applied to public medical schools and a regional quota 'Chiiki-waku' students with scholarship had lower family income and physician parents compared with those who applied to private medical schools (p<0.01), but they still had higher physician parents compared with non-medical students (p<0.01). Logistic regression revealed that having a physician parent (p<0.01), aspiring to the present profession during elementary school (p<0.01) and private upper secondary school graduation (p<0.01) predicted the likelihood of studying medicine. There were regional differences of backgrounds among medical students, and 80% of medical students with urban backgrounds intended to work in urban localities after graduation.

CONCLUSIONS

This study provides evidence that medical students in Japan hail from urban and higher income classes and physicians' families. This finding has implications for the health workforce maldistribution in Japan. Widening the diversity of medical students is essential for solving physician workforce issues and meeting broad healthcare needs.

Incorporation of virtual reality in the clinical training of medical students studying esophageal and mediastinal anatomy and surgery

PURPOSE

To analyze the effectiveness of incorporating virtual reality (VR) in lectures on esophageal and mediastinal anatomy and surgical procedures for medical students at Gifu University during clinical training.

METHODS

We divided medical students participating in clinical training, randomly, into two groups of 30 students each: those who received a lecture using 3D images (3D group) and those who received a lecture using VR images (VR group). Four days after the lecture, the students completed a written test to allow us to evaluate their comprehension, and a questionnaire on their opinion of the lectures.

RESULTS

Based on the results of the written test, the VR group achieved better understanding of computed tomography (CT) images (p = 0.0001) and better interpretation of surgical images (p = 0.0163). However, there was no difference in the scores for spatial recognition and general problems. The questionnaire revealed that the VR group became more interested in mediastinal anatomy (p = 0.0165) and surgery (p = 0.0135).

CONCLUSIONS

Our findings suggest that VR enhances the learning process. The lecture incorporating the VR experience was more effective than the traditional lecture for promoting an understanding of CT images and interpretation of surgical images; thus, it enhances the learning experience for medical students studying surgery.

Identifying and supporting students at risk of failing the National Medical Licensure Examination in Japan using a predictive pass rate

BACKGROUND

Students who fail to pass the National Medical Licensure Examination (NMLE) pose a huge problem from the educational standpoint of healthcare professionals. In the present study, we developed a formula of predictive pass rate (PPR)" which reliably predicts medical students who will fail the NMLE in Japan, and provides an adequate academic support for them.

METHODS

Six consecutive cohorts of 531 medical students between 2012 and 2017, Gifu University Graduate School of Medicine, were investigated. Using 7 variables before the admission to medical school and 10 variables after admission, we developed a prediction formula to obtain the PPR for the NMLE using logistic regression analysis. In a new cohort of 106 medical students in 2018, we applied the formula for PPR to them to confirm the capability of the PPR and predicted students who will have a strong likelihood of failing the NMLE.

RESULTS

Medical students who passed the NMLE had the following characteristics: younger age at admission, graduates of high schools located in the surrounding area, high scores in the graduation examination and in the comprehensive computer-based test provided by the Common Achievement Test Organization in Japan. However, total score of examination in pre-clinical medical sciences and Pre-CC OSCE score in the 4th year were not correlated with the PPR. Ninety-one out of 531 students had a strong likelihood of failing the NMLE between 2012 and 2017 and 33 of these 91 students failed NMLE. Using the PPR, we predicted 12 out of 106 students will have a strong likelihood of failing the NMLE. Actually, five of these 12 students failed NMLE.

CONCLUSIONS

The PPR can be used to predict medical students who have a higher probability of failing the NMLE. This prediction would enable focused support and guidance by faculty members. Prospective and longitudinal studies for larger and different cohorts would be necessary.

Good clinical teachers in pediatrics: The perspective of pediatricians in Japan

BACKGROUND

The purpose of this study was to identify the attributes of good clinical teachers in pediatrics (CTPs) in Japan, and to elucidate pediatricians and pediatric trainees' perceptions of these attributes.

METHODS

The attributes of good CTPs were identified qualitatively by conducting a thematic analysis of questionnaires answered by board-certified pediatricians and pediatric trainees. The attributes identified were rated quantitatively by a large number of participants in both groups.

RESULTS

Forty-eight individual attributes of good CTPs were identified, which were classified into three domains: personal, pediatrician, and teacher. The three domains and most of the attributes were consistent with previous studies. However, a few additional attributes, including "is kind/thoughtful toward others" and "defends trainees", which may be unique to pediatricians in Japan, were identified. Significant differences in the pediatricians' and trainees' perceptions of these attributes were elucidated: The differences were most noticeable for teacher attributes and least for personal attributes.

CONCLUSION

Although most of the identified attributes of good CTPs in our study appear to be universal, there were significant differences in the pediatricians' and trainees' perceptions of good CTPs, especially in relation to teacher attributes. Our study provides additional bases for good CTPs and future faculty development, for enhanced pediatric clinical education.

Improved cognitive apprenticeship clinical teaching after a faculty development program

BACKGROUND

While it is well known that the cognitive apprenticeship is an effective workplace-based teaching approach for clinical teachers, the effects of faculty development (FD) have not been analyzed from that perspective. The purpose of this study was to investigate self-assessment by clinical teachers of their educational perceptions and behaviors after a FD program using the cognitive apprenticeship model.

METHODS

Board-certified pediatricians who participated in a 3-day FD program on practical clinical teaching were asked to complete questionnaires. Fifty participants completed two questionnaires prior to and 3 and 6 months after the FD program: the first was on the participants' general perceptions and behaviors in relation to their own clinical education and the second was a self-assessment using the Maastricht Clinical Teaching Questionnaire (MCTQ) that was developed based on the cognitive apprenticeship model.

RESULTS

The general survey demonstrated that 78% of the participants experienced positive changes in their educational perceptions 6 months after FD. Self-assessment using the MCTQ showed that the scores in the categories of "articulation," "exploration," and "safe learning environment" remained significantly improved 6 months after the FD program.

CONCLUSIONS

The participants' self-perceived improvement in behaviors was sustainable for 6 months after participation the FD program. The results of the MCTQ show that through their experiences in the FD program, the participants seemingly transformed their clinical teaching to become interactive facilitators, encouraging self-directed learning. Our results also suggest that the MCTQ can be used for self-assessment of clinical teachers and to enhance the effectiveness of the FD program.

How does video case-based learning influence clinical decision-making by midwifery students? An exploratory study

BACKGROUND

Clinical decision-making skills are essential for providing high-quality patient care. To enhance these skills, many institutions worldwide use case-based learning (CBL) as an educational strategy of pre-clinical training. However, to date, the influence of different learning modalities on students' clinical decision-making processes has not been fully explored. This study aims to explore the influence of video and paper case modalities on the clinical decision-making process of midwifery students during CBL.

METHODS

CBL involving a normal pregnant woman was provided for 45 midwifery students. They were divided into 12 groups; six groups received the video modality, and six groups received the paper modality. Group discussions were video-recorded, and focus groups were conducted after the CBL. Transcripts of the group discussions were analysed in terms of their interaction patterns, and focus groups were thematically analysed based on the three-stage model of clinical decision-making, which includes cue acquisition, interpretation, and evaluation/decision-making.

RESULTS

The students in the video groups paid more attention to psychosocial than biomedical aspects and discussed tailored care for the woman and her family members. They refrained from vaginal examinations and electric fetal heart monitoring. Conversely, the students in the paper groups paid more attention to biomedical than psychosocial aspects and discussed when to perform vaginal examinations and electric fetal heart monitoring.

CONCLUSION

This study clarified that video and paper case modalities have different influences on learners' clinical decision-making processes. Video case learning encourages midwifery students to have a woman- and family-centred holistic perspective of labour and birth care, which leads to careful consideration of the psychosocial aspects. Paper case learning encourages midwifery students to have a healthcare provider-centred biomedical perspective of labour and childbirth care, which leads to thorough biomedical assessment.

The audience response system may help short- and long-term knowledge gain in large classrooms

This article was migrated. The article was not marked as recommended. Introduction: The audience response system (ARS) is widely used to increase active learning and expert knowledge gain from lectures. Several studies have shown its effectiveness in short-term knowledge gain, but few studies have reported on long-term knowledge gain. The present authors measured short- and long-term knowledge gain with ARS in a large class. Methods: This study was conducted during a clinical reasoning course for medical students over a 3-month period. Students completed the same questionnaire (40 multiple-choice questions) before (pretest) and after the course (posttest). The authors administered 20 ARS and 20 non-ARS questions in five different sessions during the course. Average pre- and posttest scores were compared to evaluate short- and long-term knowledge gain. Results: The average posttest score for ARS questions was 2.5 points higher than the average pretest score; a statistically significant difference. The average non-ARS posttest score was 0.2 points higher than the average pretest score, but was not statistically significant. The short- and long-term average posttest scores with ARS were higher than the average pretest scores, and were statistically significant. Conclusions: Overall knowledge gain during the course showed improvement when ARS was used.

Comparison of tutored group with tutorless group in problem-based mixed learning sessions: a randomized cross-matched study

BACKGROUND

Problem-based learning (PBL) involves discussions among students who resolve loosely-structured problems to facilitate learning. In the PBL curriculum, faculty tutors are employed as facilitators for small groups of students. Because of lack of time and staff shortage, the effectiveness of tutorless PBL has been discussed as an alternate option.

METHODS

Sessions in which tutored and tutorless PBL groups are mixed were presented by 1st-year medical students, who experienced both tutored and tutorless groups alternately in the two sessions of a year. To examine the effectiveness of tutored and tutorless PBL, written examination scores (WES) and self-contentment scores (SCS) were statistically analysed.

RESULTS

WES averages did not significantly differ between the tutored and tutorless groups; however, a significantly greater variation was observed in WES in the tutorless group. SCS averages tended to be higher in the tutored PBL than in tutorless PBL groups.

CONCLUSIONS

Students in these tutorless PBL groups performed well in their written examinations, whereas those in the tutored PBL groups, achieved this and reported better self-contentment with their learning experience. Tutorless PBL sessions were considered to be comparable to tutored PBL sessions at least in the early stages.

Enhanced expression of WD repeat-containing protein 35 (WDR35) stimulated by domoic acid in rat hippocampus: involvement of reactive oxygen species generation and p38 mitogen-activated protein kinase activation

Background

Domoic acid (DA) is an excitatory amino acid analogue of kainic acid (KA) that acts via activation of glutamate receptors to elicit a rapid and potent excitotoxic response, resulting in neuronal cell death. Recently, DA was shown to elicit reactive oxygen species (ROS) production and induce apoptosis accompanied by activation of p38 mitogen-activated protein kinase (MAPK) in vitro. We have reported that WDR35, a WD-repeat protein, may mediate apoptosis in several animal models. In the present study, we administered DA to rats intraperitoneally, then used liquid chromatography/ion trap tandem mass spectrometry (LC-MS/MS) to identify and quantify DA in the brains of the rats and performed histological examinations of the hippocampus. We further investigated the potential involvement of glutamate receptors, ROS, p38 MAPK, and WDR35 in DA-induced toxicity in vivo.

Results

Our results showed that intraperitoneally administered DA was present in the brain and induced neurodegenerative changes including apoptosis in the CA1 region of the hippocampus. DA also increased the expression of WDR35 mRNA and protein in a dose- and time-dependent manner in the hippocampus. In experiments using glutamate receptor antagonists, the AMPA/KA receptor antagonist NBQX significantly attenuated the DA-induced increase in WDR35 protein expression, but the NMDA receptor antagonist MK-801 did not. In addition, the radical scavenger edaravone significantly attenuated the DA-induced increase in WDR35 protein expression. Furthermore, NBQX and edaravone significantly attenuated the DA-induced increase in p38 MAPK phosphorylation.

Conclusion

In summary, our results indicated that DA activated AMPA/KA receptors and induced ROS production and p38 MAPK phosphorylation, resulting in an increase in the expression of WDR35 in vivo.

Bupivacaine-induced apoptosis independently of WDR35 expression in mouse neuroblastoma Neuro2a cells

Background

Bupivacaine-induced neurotoxicity has been shown to occur through apoptosis. Recently, bupivacaine was shown to elicit reactive oxygen species (ROS) production and induce apoptosis accompanied by activation of p38 mitogen-activated protein kinase (MAPK) in a human neuroblastoma cell line. We have reported that WDR35, a WD40-repeat protein, may mediate apoptosis through caspase-3 activation. The present study was undertaken to test whether bupivacaine induces apoptosis in mouse neuroblastoma Neuro2a cells and to determine whether ROS, p38 MAPK, and WDR35 are involved.

Results

Our results showed that bupivacaine induced ROS generation and p38 MAPK activation in Neuro2a cells, resulting in apoptosis. Bupivacaine also increased WDR35 expression in a dose- and time-dependent manner. Hydrogen peroxide (H₂O₂) also increased WDR35 expression in Neuro2a cells. Antioxidant (EUK-8) and p38 MAPK inhibitor (SB202190) treatment attenuated the increase in caspase-3 activity, cell death and WDR35 expression induced by bupivacaine or H₂O₂. Although transfection of Neuro2a cells with WDR35 siRNA attenuated the bupivacaine- or H₂O₂-induced increase in expression of WDR35 mRNA and protein, in contrast to our previous studies, it did not inhibit the increase in caspase-3 activity in bupivacaine- or H₂O₂-treated cells.

Conclusions

In summary, our results indicated that bupivacaine induced apoptosis in Neuro2a cells. Bupivacaine induced ROS generation and p38 MAPK activation, resulting in an increase in WDR35 expression, in these cells. However, the increase in WDR35 expression may not be essential for the bupivacaine-induced apoptosis in Neuro2a cells. These results may suggest the existence of another mechanism of bupivacaine-induced apoptosis independent from WDR35 expression in Neuro2a cells.

Role of naofen in apoptosis of hepatocytes induced by lipopolysaccharide through mitochondrial signaling in rats

AIM

  Lipopolysaccharide (LPS) causes apoptosis of hepatocytes, which is probably mediated by inflammatory substances released from Kupffer cells (KCs). Recently, we have reported that naofen, a newly found intracellular WD40-repeat protein, has a role in inducing the apoptosis in HEK293 cells. Hence, the present study was undertaken to investigate a role of naofen in the LPS-induced apoptosis of rat hepatocytes.

METHODS

  Rats were treated with i.v. injections of LPS, and livers were extirpated to evaluate expression of naofen and apoptosis. In in vitro experiments, hepatocytes and KCs were separately isolated from rat livers. The incubation medium for KCs treated with LPS (KC-CM) was used for hepatocyte culture.

RESULTS

  Intravenous injections of LPS enhanced the expression of naofen in the livers. Livers showed terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL)-positive staining, and elevated caspase-3 activity. In isolated KCs or hepatocytes, LPS hardly affected naofen expression and caspase-3 activity, whereas incubation of hepatocytes with KC-CM enhanced both naofen expression and caspase-3 activation. Transfection of hepatocyte with naofen siRNA prevented such effects of KC-CM, and clearly eliminated KC-CM-induced reduction of Bcl-2 and Bcl-xL. In contrast, overexpression of naofen in hepatocytes downregulated Bcl-2 and Bcl-xL, released cytochrome c from mitochondria, and activated caspase-3.

CONCLUSION

  These results indicate that LPS may induce the hepatic apoptosis in association with enhanced naofen expression, and that naofen may mediate the activation of caspase-3 through downregulating the Bcl-2 and Bcl-xL expression, and releasing cytochrome c from mitochondria to cytoplasm.

Effect of L-arginine supplement on liver regeneration after partial hepatectomy in rats

Background

Nitric oxide (NO) has been reported to be a key mediator in hepatocyte proliferation during liver regeneration. NO is the oxidative metabolite of L-arginine, and is produced by a family of enzymes, collective termed nitric oxide synthase (NOS). Thus, administration of L-arginine might enhance liver regeneration after a hepatectomy. Another amino acid, L-glutamine, which plays an important role in catabolic states and is a crucial factor in various cellular and organ functions, is widely known to enhance liver regeneration experimentally. Thus, the present study was undertaken to evaluate the effects of an L-arginine supplement on liver regeneration, and to compared this with supplementation with L-glutamine and L-alanine (the latter as a negative control), using a rat partial hepatectomy model.

Methods

Before and after a 70% hepatectomy, rats received one of three amino acid solutions (L-arginine, L-glutamine, or L-alanine). The effects on liver regeneration of the administered solutions were examined by assessment of restituted liver mass, staining for proliferating cell nuclear antigen (PCNA), and total RNA and DNA content 24 and 72 hours after the operation.

Results

At 72 hours after the hepatectomy, the restituted liver mass, the PCNA labeling index and the DNA quantity were all significantly higher in the L-arginine and L-glutamine groups than in the control. There were no significant differences in those parameters between the L-arginine and L-glutamine groups, nor were any significant differences found between the L-alanine group and the control.

Conclusion

Oral supplements of L-arginine and L-glutamine enhanced liver regeneration after hepatectomy in rats, suggesting that an oral arginine supplement can clinically improve recovery after a major liver resection.

Identification, localisation and functional implication of 26RFa orthologue peptide in the brain of zebra finch (Taeniopygia guttata)

Several neuropeptides with the C-terminal Arg-Phe-NH(2) (RFa) sequence have been identified in the hypothalamus of a variety of vertebrates. The present study was conducted to isolate novel RFa peptides from the zebra finch brain. Peptides were isolated by immunoaffinity purification using an antibody that recognises avian RFa peptides. The isolated peptide consisted of 25 amino acids with RFa at its C-terminus. The sequence was SGTLGNLAEEINGYNRRKGGFTFRFa. Alignment of the peptide with vertebrate 26RFa has revealed that the identified peptide is the zebra finch 26RFa. We also cloned the precursor cDNA encoding this peptide. Synteny analysis of the gene showed a high conservation of this gene among vertebrates. In addition, we cloned the cDNA encoding a putative 26RFa receptor, G protein-coupled receptor 103 (GPR103) in the zebra finch brain. GPR103 cDNA encoded a 432 amino acid protein that has seven transmembrane domains. In situ hybridisation analysis in the brain showed that the expression of 26RFa mRNA is confined to the anterior-medial hypothalamic area, ventromedial nucleus of the hypothalamus and the lateral hypothalamic area, the brain regions that are involved in the regulation of feeding behaviour, whereas GPR103 mRNA is distributed throughout the brain in addition to the hypothalamic nuclei. When administered centrally in free-feeding male zebra finches, 26RFa increased food intake 24 h after injection without body mass change. Diencephalic GPR103 mRNA expression was up-regulated by fasting for 10 h. Our data suggest that the hypothalamic 26RFa-its receptor system plays an important role in the central control of food intake and energy homeostasis in the zebra finch.

Influence of thyroid hormones and transforming growth factor-β1 on cystatin C concentrations

Serum cystatin C concentrations are reported to increase in the hyperthyroid state. Serum concentrations of cystatin C and transforming growth factor-β1 (TGF-β1) were measured in patients with thyroid dysfunction, and the effects of 3,5,3'-tri-iodothyronine (T(3)) and TGF-β1 on cystatin C production in human hepatoblastoma (Hep G2) cells were studied. Serum concentrations of cystatin C and TGF-β1 were significantly higher in patients with Graves' disease compared with control subjects. Significantly positive correlations were observed between thyroid hormones and cystatin C, thyroid hormones and TGF-β1, and TGF-β1 and cystatin C in patients with thyroid dysfunction. Serum concentrations of cystatin C and TGF-β1 decreased after treatment for hyperthyroidism. Cystatin C mRNA levels and cystatin C secretion were increased by T(3) and TGF-β1 in cultured Hep G2 cells. These results suggest that serum cystatin C concentrations increase in patients with hyperthyroidism. The mechanisms for this may involve elevation of serum TGF-β1 levels and the stimulatory effects of T(3) and TGF-β1 on cystatin C production.

Effects of 1-O-hexyl-2,3,5-trimethylhydroquinone on carbon tetrachloride-induced hepatic cirrhosis in rats

AIM

The present study was undertaken to evaluate the effects of 1-O-hexyl-2,3,5-trimethylhydroquinone (HTHQ), a synthesized vitamin E derivative, on carbon tetrachloride (CCl(4))-induced cirrhosis.

METHODS

Rats were treated with hypodermic injections of CCl(4) twice a week to induce the hepatic cirrhosis, and given drinking water containing HTHQ or solvent. Primary cultures of rat hepatocytes were performed to evaluate the effects of HTHQ on the expression of inducible nitric oxide synthase (iNOS).

RESULTS

Masson's staining of rat livers showed fibrosis around pseudo-lobules in the CCl(4) group, the lesions being reduced in the CCl(4) HTHQ group. Increases in liver tissue hydroxyproline and alpha(1)(I) collagen, alpha-smooth muscle actin and iNOS induced by CCl(4), were also markedly diminished by HTHQ. Furthermore, both HTHQ and vitamin E attenuated interleukin-1beta-induced iNOS protein expression in cultured hepatocytes, the potency of HTHQ being 10-times higher than that of vitamin E.

CONCLUSION

HTHQ may inhibit development of hepatic cirrhosis in rats, more potently than vitamin E, by inhibiting the iNOS expression in hepatocytes. Because vitamin E has a radical scavenging action, roles of NO and peroxynitrite will be discussed in the effects of HTHQ on the fibrosis.

Enhanced expression of naofen in kidney of streptozotocin-induced diabetic rats: possible correlation to apoptosis of tubular epithelial cells

BACKGROUND

Hyperglycemia/high glucose may induce apoptosis in diabetic kidney, but the mechanism is not fully understood. Naofen was found as a Shiga toxin (Stx)-2-related protein. Based on renal dysfunction in infection with Stx-producing Escherichia coli and on participation of naofen in apoptosis of human embryonic kidney cells, the present study was undertaken to investigate the mechanism of renal dysfunction in diabetes mellitus with particular reference to naofen.

METHODS

In in vivo studies utilizing streptozotocin (STZ)-induced diabetic rats, and also in in vitro cultured rat kidney epithelial (NRK52E) cells, naofen messenger RNA (mRNA) and protein expressions were analyzed. Naofen mRNA location in diabetic kidney was studied by in situ hybridization. Apoptosis was assessed by caspase-3 activity assay.

RESULTS

Rat diabetic kidney showed significant increases in caspase-3 activities and naofen mRNA. Naofen was mainly observed at both proximal and distal urinary tubules. Incubation of NRK52E cells in high glucose medium resulted in elevated naofen mRNA expression, whereas neither interleukin-1, interleukin-6, nor tumor necrosis factor-alpha elicited such action. Moreover, treatment of NRK52E cells with naofen small interfering RNA (siRNA) inhibited naofen mRNA expression induced by high glucose and blocked the increase in caspase-3 activity.

CONCLUSIONS

These data suggest that naofen expression may be upregulated by hyperglycemia, with possible correlation to apoptosis of tubular epithelial cells and thereby to diabetic nephropathy.

Naofen, a novel WD40-repeat protein, mediates spontaneous and tumor necrosis factor-induced apoptosis

Naofen has recently been identified from the rat brain/spinal cord cDNA library as a substance reactive against an anti-shigatoxin (Stx)-2 antibody. Naofen mRNA is composed of 4620 nucleotides and encodes 1170 amino acids. Naofen contains four WD-repeat domains in its N-terminus and is ubiquitously distributed in many tissues of the rat. Tumor necrosis factor (TNF)-alpha enhanced the expression of naofen mRNA in HEK293 cells in a dose-dependent manner. Furthermore, naofen siRNA, which predominantly knocked down the expression of naofen mRNA, significantly reduced both TNF-alpha-induced caspase-3 activation and apoptosis in HEK293 cells. Overexpression of naofen in HEK293 cells (FLAG-NF) spontaneously induced caspase -3 activation and apoptosis, and showed extremely high susceptibility to TNF-alpha-induced apoptosis. These results indicated that naofen may function as a novel modulator activating caspase-3, and promoting TNF-alpha-stimulated apoptosis.

Roles of naofen, a novel WD-repeat-2 protein, in the CCl4-treated livers--a possible relationship to cell proliferation

Naofen (GenBank accession no. EF613262), a newly found intracellular protein in the WD-repeat-2 protein family, has been cloned as an anti-verotoxin II antibody immunoreactive substance, and the nucleotide- and amino acid-sequences have been clarified. The present study was undertaken to evaluate the roles of naofen especially in carbon tetrachloride (CCl4-induced cirrhosis model of rats, also in partial hepatectomy. Naofen mRNA expressions were observed from the early phases of cirrhosis development and during regenerative phases after partial hepatectomy, more remarkable in the former. Naofen immunoreactive fragments located in the vascular endothelial cells and peri-vascular spaces in normal livers especially in Glisson's areas, being strongly stained in the connective tissues 8 weeks after starting CCl4-injections, besides in the cytoplasm of hepatocytes in pseudo-lobules. In contrast, partial hepatectomy caused a small increase of naofen expressions in the whole hepatocytes, and significantly in the endothelial cells of portal veins and hepatic arterioles. Furthermore, in parallel to the degree of naofen mRNA and protein expressions, the rates of double-nuclei cells to total hepatocytes in the Glisson's areas increased in both cirrhosis and partial hepatectomy, suggesting a relationship between naofen expression and mitosis. In in-vitro studies with cell lines, vascular endothelial growth factor, a cell proliferation stimulant, increased the naofen mRNA expressions in HepG(2) cell lines, whereas paclitaxel, a cytotoxic anti-cancer drug, diminished them in NRK52E, both concentration-dependently. These results indicated that naofen immunoreactive fragments play an important role in the cell proliferation, relevant for analyzing the regenerative phases during cirrhosis developments and after partial hepatectomy.

Spin-torque diode effect in magnetic tunnel junctions

There is currently much interest in the development of 'spintronic' devices, in which harnessing the spins of electrons (rather than just their charges) is anticipated to provide new functionalities that go beyond those possible with conventional electronic devices. One widely studied example of an effect that has its roots in the electron's spin degree of freedom is the torque exerted by a spin-polarized electric current on the spin moment of a nanometre-scale magnet. This torque causes the magnetic moment to rotate at potentially useful frequencies. Here we report a very different phenomenon that is also based on the interplay between spin dynamics and spin-dependent transport, and which arises from unusual diode behaviour. We show that the application of a small radio-frequency alternating current to a nanometre-scale magnetic tunnel junction can generate a measurable direct-current (d.c.) voltage across the device when the frequency is resonant with the spin oscillations that arise from the spin-torque effect: at resonance (which can be tuned by an external magnetic field), the structure exhibits different resistance states depending on the direction of the current. This behaviour is markedly different from that of a conventional semiconductor diode, and could form the basis of a nanometre-scale radio-frequency detector in telecommunication circuits.

[Efficacy of FEM (5-fluorouracil, epirubicin, mitomycin C) therapy for resected advanced gastric cancer. Ehime Gastric Cancer Study Meeting]

Between April 1990 and March 1991, postoperative adjuvant chemotherapy for resected gastric cancer employing 5-fluorouracil, epirubicin and mitomycin C (FEM) was performed. Forty-two patients subjected to the therapy were considered to have positive serosal invasion and underwent curative operation. FEM therapy consisted of intraoperative intraperitoneal administration of mitomycin C (0.3-0.4 mg/kg) combined with 8 cycles of intravenous bolus injection of epirubicin (20 mg/body) every 2-3 weeks which was started 2 weeks after the operation. Daily oral administration of 5-fluorouracil (150-200 mg/body) was started 2 weeks after the operation and continued for more than 6 months. Thirty-four of the 42 cases were assessable. Major adverse effects were nausea, vomiting, and general fatigue. There were no cardiovascular symptoms. The cumulative two-year survival rate was 74.2%, and follow-up was still under way at this writing.

[The effect of prostacyclin (PGI) on denervated tissues--especially, about denervation supersensitivity]

It is well known that contractive agents of smooth muscle have denervation supersensitivity. But, the existence of denervation supersensitivity in relaxed ones does not become so clear. We investigated these supersensitivity, especially prostacyclin (PGI2). We made the denervated artery by lumbar sympathetic ganglionectomy in mongrel dogs. Namely, saphenous and dorsal pedal arteries were denervated by this ganglionectomy. And we studied the changes of these arterial tensions by magnus apparatus. Dose-response (D-R) curves of denervated arteries for KCl and noradrenaline (NE) shifted to left against control arteries. Next, we studied effects of PGI2. At first, we measured ED50 of KCl and NE contraction. And, we produced the half contraction on each artery by using ED50 of KCl and NE. Lastly, PGI2 was added on the half contractive arteries to study relaxed changes. D-R curves of denervated arteries for PGI2 shifted to left, too. These denervated arteries acquired the supersensitivity for PGI2. Clinically, if we use relaxants after organ transplantation, these drugs may be very effective for the perfusion of the grafts.

Afferent innervation of the gallbladder in the cat, studied by the horseradish peroxidase method

Following injection of horseradish peroxidase (HRP) into the wall of the gallbladder of cats, HRP-positive cells were found bilaterally in dorsal root ganglia T2-L3 (T2-L2, and T3-L2/L3 also observed in a few cats) and nodose ganglia. In about 33% of animals labelled cells were also distributed in cervical dorsal root ganglia C5-C7. Labelled cells were more frequently localized on the right side than the left. There was no apparent change in numbers of labelled cells in the nodose ganglion (NG) on either side following greater and lesser splanchnicotomy or section of the right phrenic nerve or removal of the celiac ganglion. After severing both the greater and lesser splanchnic nerves unilaterally, numbers of labelled afferent cells from the gallbladder in dorsal root ganglia (DRGs) significantly decreased on the ipsilateral side but there was no change in the pattern of distribution contralaterally. After section of the right phrenic nerve, labelled cells were not found in ipsilateral cervical ganglia. That some afferent fibers from the gallbladder travel via the phrenic nerves, particularly on the right side, may be a supplementary mechanism in the generation of referred pain in gallbladder disease. The splanchnic nerves are the main, but not the only pathway for afferent fibers from the gallbladder.

Participation of the parasympathetic nervous system in the development of activity-stress ulcers

The present study investigates the effects of truncal vagotomy and drug treatment, comprising atropine methylbromide and chlorisondamine, on the development of activity-stress ulcers in rats. To induce gastric lesions, female rats were housed individually in activity-wheel cages and subjected to a food-restricted schedule of only 1 hr food availability per day. Bilateral truncal vagotomy significantly prevented gastric ulceration, while those rats with vagotomy showed more running activity than sham-operated rats. Daily treatment with either methylatropine (3 and 6 mg/kg, s.c.) or chlorisondamine (2 and 4 mg/kg, i.p.) also significantly decreased the severity of lesions without a significant reduction in running activity. This evidence suggests that the development of activity-stress ulcers is mainly due to the hyperactivity of the peripheral parasympathetic nervous system.

Polymorphisms of serum proteins in Japanese patients with vascular diseases. I. Factor XIIIB, plasminogen and complement types in primary varicose veins

The polymorphisms of the B subunit of coagulation factor XIII (F13B), plasminogen (PLG), complement C6, C7, factor B (BF) and factor I (IF) were studied among 21 unrelated Japanese patients with primary varicose veins (PVV) by isoelectric focusing followed by immunoblotting. The allele frequencies for F13B*2 and IF*A in PVV patients were significantly higher (F13B*2, p = 0.0047; IF*A, p = 0.0006) than those in healthy controls (n = 60). Significant associations of F13B 2 allotype [p = 0.0220, relative risk (RR) = 13.9] and IF A allotype (p = 0.0006, RR = 10.0) with PVV were observed; however, no significant association of PLG, C6, C7 or BF allotype with the disease was found.

Deformation response of red blood cells in oscillatory shear flow

The characteristics of red cell deformation were studied, focusing on deformation response of the cells subjected to oscillatory shear stress. Red blood cells were fractionated into subpopulations of different densities, i.e., low-density and high-density cells. The deformation response of the fractionated cells was evaluated with a rheoscope varying their intracellular viscosity and oscillation frequency of the applied shear stress, and determinants of the deformation response were compared with those of whole cell deformation under stationary shear stress. When the fractionated cells were exposed to sinusoidally oscillated shear stress, the cells underwent oscillatory deformation. The degree of deformation of the low-density cells correspond to the magnitude of the applied shear stress up to an oscillation frequency of 2.7 Hz. Meanwhile, such an oscillatory deformation as to correspond to the applied shear stress was observed up to 1.7 Hz for the high-density cells. It was suggested that intracellular viscosity was an important factor to determine the deformation response of red cells to oscillatory shear stress.

Regulatory role of enteric mu and kappa opioid receptors in the release of acetylcholine and norepinephrine from guinea pig ileum

We examined the role of opioid receptor subtypes in the contraction and release of acetylcholine (ACh) and norepinephrine in longitudinal muscle-myenteric plexus preparations of the guinea pig ileum. [D-Ala2, N-Me-Phe4, Gly5-ol]enkephalin (DAMGO) (10(-8) to 10(-5) M) inhibited the contraction and the release of ACh evoked by 0.2 and 1 Hz of electrical stimulation (ES), whereas the response to 5 Hz was enhanced by low concentrations of DAMGO (10(-9) to 10(-8) M) and inhibited by high concentrations (10(-7) to 10(-5) M); naloxone antagonized these effects. In preparations treated with yohimbine, DAMGO inhibited the ES (5 Hz)-evoked contraction and ACh release, but failed to enhance either effect. Dynorphin-A inhibited the contraction and ACh release evoked by 0.2, 1 and 5 Hz of ES, and the effect of dynorphin-A was mimicked by U-69593 [5 alpha,7 alpha,8 beta-(-)-N-methyl-N-[7- (pyrrolinyl)-1-ozaspiro(4,5)dec-8-yl]-benzene] and antagonized by MR 2266 [(-)-alpha-5,9-diethyl-2-(3-furylmethyl)-2'-hydroxy-6,7-benzomorphan]. The release of norepinephrine evoked by 5 Hz of ES was inhibited by DAMGO (10(-10) to 10(-6) M), but not by U-69593, and the effect of DAMGO was antagonized by naloxone. Thus, it would appear that mu-opioid receptors are present on both cholinergic and adrenergic neurons, whereas kappa-opioid receptors are present on cholinergic neurons. The affinity of DAMGO was 30 times higher for the mu-opioid receptors on the adrenergic than on the cholinergic neurons.(ABSTRACT TRUNCATED AT 250 WORDS)

Drug interaction between phenytoin and allopurinol

The combination of phenytoin (DPH) and allopurinol is used for the treatment of a neurological disease. However, interactions between DHP and allopurinol and the mechanism are little known. The repeated dosing of allopurinol at higher doses (20 and 50 mg/kg) significantly retarded the elimination of DPH from the circulation and dramatically decreased the urinary excretion of p-hydroxyphenytoin (HPPH), a major metabolite of DPH. However, a single administration of allopurinol (10 or 50 mg/kg) did not give rise to these effects. Allopurinol did not affect the hepatic extraction of DPH and renal plasma flow rate. Allopurinol (50 mg/kg/d) dosed repeatedly could not inhibit the hepatic drug metabolizing enzyme activities. The in vitro hydroxylation of DPH was inhibited only slightly and the kinetic plots gave apparently non-competitive inhibition. The less inhibitory effect of allopurinol on the in vitro hydroxylation did not agree with the in vivo data. These results indicate that the inhibitory effect of allopurinol is not mediated by cytochrome P-450 dependent monooxygenase reactions.

Sympathetic supply to the arteries of canine hindlimbs

Sympathetic supply to the saphenous and dorsal pedal arteries of canine hindlimbs was determined using the glyoxylic acid method for monoamines for the fluorescence histochemical demonstration. Adrenergic nerve fibers of the dorsal pedal artery had almost completely disappeared after L6, L7 sympathectomy. The fibers of the saphenous artery had disappeared by about 90% by L3-L5 sympathectomy. It is concluded that all the postganglionic fibers distributed to the dorsal pedal artery originate in L6 and L7 ganglia and 90% of those distributed to the saphenous artery originate in L3-L5 ganglia.

[A case of primary intracranial malignant lymphoma associated with gastric carcinoma]

A case of synchronous multiple primary neoplasms, an intracranial malignant lymphoma and a gastric carcinoma, is presented. A 63-year-old man was admitted to our hospital with complaints of dizziness and a floating sensation on gait. A CT scan after admission, revealed a well-defined, nodular high density area in the left frontal lobe, which was markedly enhanced by the contrast medium. In order to rule out a metastatic brain tumor, examinations were performed as a consequence, and, the gastric carcinoma was found. A partial removal of the brain tumor and a gastrectomy were performed in two stages. Pathologically, the diagnosis of the brain tumor indicated a malignant lymphoma of large cell type, and that of the gastric carcinoma was an adenocarcinoma. The patient received postoperative irradiation and chemotherapy and was discharged in a good condition. He died of pneumonia 21 months after the operation. Necropsy revealed a marked atrophy of the brain without recurrence of the malignant lymphoma and no recurrence of a gastric cancer.

Choriocarcinomatous change with immunocytochemically HCG-positive cells in the gastric carcinoma of the males

Gastric choriocarcinoma is a rare tumor and attracts interest because of its controversial pathogenesis. The present study reports a choriocarcinomatous change with immunocytochemically hCG-positive cells in the gastric carcinoma. The patients were males, one was 41 years old and the other 42 years old. The tumor of both cases consists of adenocarcinoma and choriocarcinoma. A sequential process of morphological transition of the adenocarcinoma to the choriocarcinoma can be traced. Indirect immunoperoxidase stain (PAP method) for human chorionic gonadotropin (hCG) demonstrates the localization of hCG in the syncytiotrophoblasts. Small number of cytotrophoblasts are weakly positive. None of the components of adenocarcinoma of both cases is positive for hCG. Human placental lactogen is not demonstrated in both cases. Stain for pregnancy specific beta-1 glycoprotein is weakly positive in the adenocarcinoma of one case but not in the choriocarcinoma. In one case, the concentration of hCG was 19.9 mIU/ml in the preoperative serum and decreased to 1.2 mIU/ml after gastrectomy. HCG production by gastric carcinoma was discussed with regard to possible pathogenesis of gastric choriocarcinoma.

A serious problem of the heated thermocouple flowmeter

In the measurement of regional blood flow with heated thermocouple flowmeter, we frequently observed puzzling phenomenon that the measured values were augmented while the flow was actually diminished and vice versa (Inversion). "Inversion" was directly attrebutable to the structure of the thermocouple probe. A countermeasure against "Inversion" was found to lie in the arrangement of the hot junction in the center of the heater, and in practical application, it must be checked by stopping the flow at each measurement. Overcoming this technical liability should pave the way for a marked improvement in the reliability of this method which, despite possessing many excellent characteristics for determining regional blood flow, is not widely used.

Quantitative histological study of spinal afferent innervation on the ventral surface of the cat stomach by horseradish peroxidase (HRP) method

Retrograde axonal transport of horseradish peroxidase (HRP) was applied to the ventral surface of the cat stomach. We investigated the number, size and distribution of HRP-positive cells in spinal ganglia. The unexpected finding was the wide distribution of these cells from T3 down to L3. This would result in a diffuse pattern of referred pain.

The occurrence of small, intensely fluorescent (SIF) cells in human sympathetic ganglia

Small, intensely fluorescent (SIF) cells were found histochemically in lumbar sympathetic ganglia (L2) obtained from sympathectomy of 3 patients suffering from chronic occlusive diseases of leg arteries. 3 types of SIF cells were distinguished. These cells will probably contain dopamine.

Surgical treatment of vascular lesions of the spinal cord

Paravertebral block and resection of upper thoracic sympathetic ganglions were performed on cases in which vascular disturbance of the spinal cord was considered partly responsible. Block was performed in 14 cases and clinical improvement was seen in 10 cases out of them while resection was considered effective in 2 out of 3 cases. The evoked EMG of patients was assumed recovery of a part of synaptic function in the ischemic cord after the block. On the other hand, the skin temperature of the lower extremity did not show considerable change and this supports the view that the restoration of clinical picture was not due to the improvement of the periphral circulation of extremities. From these observations, it would be well presumed that favorable effect of sympathectomy consists partly in the improvement of vascular disturbance of the spinal cord.