Low cyclosporine concentrations in children and time to acute graft versus host disease

Background

Achievement of target blood concentrations of cyclosporine (CsA) early after transplantation is known to be highly effective for reducing the incidence of acute graft versus host disease (aGVHD). However, no research has been conducted for predicting aGVHD occurrence with low CsA concentrations at different time periods. The objective of this study was to investigate the risk of aGVHD according to low CsA concentrations at lag days in children with allogenic hematopoietic stem cell transplantation (HSCT).

Methods

The records of 61 consecutive children who underwent allogeneic HSCT and received CsA as prophylaxis against aGVHD between May 2012 and March 2015 were retrospectively evaluated. The main outcome was any association between low CsA concentrations at lag days and aGVHD occurrence, which was examined for the first month after transplantation. Mean CsA concentrations at three lag periods were calculated: lag days 0–6, 7–13, and 14–20 before aGVHD occurrence.

Results

Patients whose mean CsA concentrations at lag days 0–6 did not reach the initial target concentration had 11.0-fold (95% confidence interval [CI]: 2.3–51.9) greater incidence of aGVHD. In addition, the AORs of low CsA concentrations at lag days 7–13 and 14–20 for developing aGVHD were 108.2 (95% CI: 7.7–1515.5) and 12.1 (95% CI: 1.1–138.1), respectively.

Conclusions

After low CsA concentrations are detected, careful attention needs to be paid to prevent aGVHD.

Korean medical students' attitudes toward academic misconduct: a cross-sectional multicenter study

PURPOSE

This study investigated medical students' attitudes toward academic misconduct that occurs in the learning environment during the pre-clinical and clinical periods.

METHODS

Third-year medical students from seven medical schools were invited to participate in this study. A total of 337 of the 557 (60.5%) students completed an inventory assessing their attitudes toward academic misconduct. The inventory covered seven factors: scientific misconduct (eight items), irresponsibility in class (six items), disrespectful behavior in patient care (five items), dishonesty in clerkship tasks (four items), free riding on group assignments (four items), irresponsibility during clerkship (two items), and cheating on examinations (one item).

RESULTS

Medical students showed a strict attitude toward academic misconduct such as cheating on examinations and disrespectful behavior in patient care, but they showed a less rigorous attitude toward dishonesty in clerkship tasks and irresponsibility in class. There was no difference in students' attitudes toward unprofessional behaviors by gender. The graduate medical school students showed a stricter attitude toward some factors of academic misconduct than the medical college students. This difference was significant for irresponsibility in class, disrespectful behavior in patient care, and free riding on group assignments.

CONCLUSION

This study indicates a critical vulnerability in medical students' professionalism toward academic integrity and responsibility. Further study evidence is needed to confirm whether this professionalism lapse is confined only to this population or is pervasive in other medical schools as well.

Amomum tsao-ko fruit extract suppresses lipopolysaccharide-induced inducible nitric oxide synthase by inducing heme oxygenase-1 in macrophages and in septic mice

Amomum tsao-ko Crevost et Lemarié (Zingiberaceae) has traditionally been used to treat inflammatory and infectious diseases, such as throat infections, malaria, abdominal pain and diarrhoea. This study was designed to assess the anti-inflammatory effects and the molecular mechanisms of the methanol extract of A. tsao-ko (AOM) in lipopolysaccharide (LPS)-induced RAW 264.7 macrophages and in a murine model of sepsis. In LPS-induced RAW 264.7 macrophages, AOM reduced the production of nitric oxide (NO) by inhibiting inducible nitric oxide synthase (iNOS) expression, and increased heme oxygenase-1 (HO-1) expression at the protein and mRNA levels. Pretreatment with SnPP (a selective inhibitor of HO-1) and silencing HO-1 using siRNA prevented the AOM-mediated inhibition of NO production and iNOS expression. Furthermore, AOM increased the expression and nuclear accumulation of NF-E2-related factor 2 (Nrf2), which enhanced Nrf2 binding to antioxidant response element (ARE). In addition, AOM induced the phosphorylation of extracellular regulated kinase (ERK) and c-Jun N-terminal kinase (JNK) and generated reactive oxygen species (ROS). Furthermore, pretreatment with N-acetyl-l-cysteine (NAC; a ROS scavenger) diminished the AOM-induced phosphorylation of ERK and JNK and AOM-induced HO-1 expression, suggesting that ERK and JNK are downstream mediators of ROS during the AOM-induced signalling of HO-1 expression. In LPS-induced endotoxaemic mice, pretreatment with AOM reduced NO serum levels and liver iNOS expression and increased HO-1 expression and survival rates. These results indicate that AOM strongly inhibits LPS-induced NO production by activating the ROS/MAPKs/Nrf2-mediated HO-1 signalling pathway, and supports its pharmacological effects on inflammatory diseases.

The market trend analysis and prospects of scaffolds for stem cells

Background

Scaffolds are one of the three most important elements constituting the basic concept of regenerative medicine, and are included in the core technology of regenerative medicine along with stem cells and tissue engineering. Stem cells are very important technology because they are directly responsible for the regenerative treatment of the disease and the damaged tissue, but with regards to the technology and the products that use stem cells exclusively, there is a technical limitation of limited survival rate and the engraftment rate of the transplanted cell, and rather than recovering the damaged tissue fundamentally, there is a limit that the concept is more of just another medicine treatment using cells.

A scaffold is a natural or synthetic biocompatible material transplanted into a human body to be used as the exclusive treatment or as an assisted method of another treatment of a disease and for the recovery of damaged tissue. Therefore, according to the characteristics of the tissue to be applied, scaffolds must have the characteristics such as the excellent biocompatibility, biodegradability, minimum immunity and inflammation, proper mechanical strength and interaction between the material and the cells.

Results

The world stem cell market was approximately 2.715 billion dollars in 2010, and with a growth rate of 16.8% annually, a market of 6.877 billion dollars will be formed in 2016. From 2017, the expected annual growth rate is 10.6%, which would expand the market to 11.38 billion dollars by 2021. Meanwhile, the world scaffold element technology market was approximately 4.57 million dollars in 2013, and by increasing 13.4% annually, it is estimated to expand to 10.63 million dollars by 2020. The Korean scaffold element technology market was about 22 million dollars in 2013, and with a steady growth of approximately 13.4% every year, it is prospected to be about 52 million dollars by 2020.

Conclusions

In comparison to the medical material and medicine sales growth rate, the future scaffold element technology market is judged to be higher in growth possibility.

Analysis of Verbal Interactions in Problem-based Learning

PURPOSE

Problem-based learning (PBL) is a constructive learning environment that solves ill-structured problems through collaborative learning. The purpose of this study was to analyze the interaction of students and a tutor in a small-group PBL discussion. This study examined how the types of interactions are composed over the meeting.

METHODS

Fourteen third-year subjects from Chonnam National University Medical School, Korea formed two tutorial groups. Two tutorial sessions were videotaped and analyzed. All videotapes were transcribed to analyze the interaction type. The criteria of interaction analysis were learning-oriented interaction (exploratory questioning, cumulative reasoning, handling conflicts about the knowledge), procedural interactions, and irrelevant task interactions.

RESULTS

Nearly all discourses between tutors and students were learning-oriented interactions. The results showed that students spent more time on cumulative reasoning. In contrast, tutors implemented more exploratory questioning. Little time was spent on handling conflicts about knowledge and procedural and irrelevant/off-task interactions.

CONCLUSION

To improve critical thinking and problem-solving competence in PBL, we should consider various efforts to encourage discussion about conflicting knowledge. A PBL tutor training program should be provided to facilitate PBL group discussions.

Changes of Epistemological Beliefs and Self-regulated Learning in Problem-based Learning

PURPOSE

Epistemological beliefs (EBs) are fundamental assumptions about the nature of knowledge and learning. Self-regulation (SR) is the ability and willingness to effectively use and monitor cognitive strategies. Problem-based learning (PBL) emphasizes meaningful learning through solving ill-structured problems. PBL, as a constructivist learning environment, affects students' epistemological beliefs (EBs) and self-regulation learning (SRL). The purpose of this study was to investigate the change in EBs and SRL between pre- and post-PBL.

METHODS

The subjects were 123 third-year medical students who attended Chonnam National University Medical School (CNUMS), Korea. Participants had to fill out a questionnaire concerning epistemological beliefs and self-regulated learning before and after PBL.

RESULTS

Students' EBs about rigid learning was positively changed; however, certainty of knowledge and speed of knowledge acquisition were negatively changed after PBL. Students' SRL related to self-efficacy and self-regulation was significantly improved in PBL. There was no significant change with regard to internal value, cognitive strategy, and anxiety.

CONCLUSION

EBs on certainty of knowledge and speed of knowledge acquisition were negatively changed after PBL. This result may be due to other leaning environments besides PBL i.e., the lecture-based objective learning environment of medical school. It is suggested that partial PBL cannot fully change students' EBs to higher levels. Students' SR about self-efficacy and self-regulation was significantly improved in PBL. The characteristics of PBL: small-group discussion and co-operative team activity, as well as students-centered learning environments, facilitate self-efficacy, and self-regulation.

Antenatal risk factors, cytokines and the development of atopic disease in early childhood

Atopic diseases are complex entities influenced by an array of risk factors, including genetic predisposition, environmental allergens, antenatal exposures, infections and psychosocial factors. One proposed mechanism by which these risk factors contribute to the development of atopic disease is through changes in the production of T helper cell type 1 (Th1) and T helper cell type 2 (Th2) cytokines. The objectives of this review are to discuss antenatal exposures that are associated with paediatric atopic diseases, to discuss the influence of the intrauterine environment on neonatal immune responses, to provide an overview of the Th1 and Th2 pathways and how they relate to atopic disease, and to summarise our current understanding of the association between cytokine responses in cord blood and the development of atopic disease in early childhood.

High dose antipsychotic use in schizophrenia: findings of the REAP (research on east Asia psychotropic prescriptions) study

BACKGROUND

High-dose antipsychotic regimes (defined as the prescription of more than 1000 chlorpromazine-equivalents milligrams of antipsychotic per day) in the management of patients with schizophrenia are not uncommon, but most reports are from western countries. Recent functional neuroimaging studies have found that the previous notion concerning the use of antipsychotic medication, especially in high doses, was unsupported and untenable.

METHODS

This international study examined the use of high dose antipsychotic medication and its clinical correlates in schizophrenia patients within six East Asian countries/territories.

RESULTS

Within the study group (n = 2399), 430 patients (17.9%) were prescribed high dose antipsychotics. Antipsychotic use varied significantly between countries, with Japan, Korea, and Singapore using higher doses than the other countries. High dose antipsychotic use was associated with younger age in Japan (p < 0.001), longer duration of admission (p < 0.001), duration of illness (p < 0.001, particularly in Korea and Taiwan), positive psychotic symptoms (p < 0.001, particularly in Japan and Korea), and aggression (p < 0.05, particularly in Japan), and also with a higher likelihood of extrapyramidal and autonomic adverse effects (p < 0.05, particularly in China). Country, younger age, the presence of delusions and disorganized speech, polypharmacy, and receiving depot medication but not atypical antipsychotic drugs were important predictors of high antipsychotic use.

CONCLUSIONS

This survey revealed that high antipsychotic dosing is not an uncommon practice in East Asia. It behooves the prescribing clinicians to constantly reevaluate the rationale for such a practice.

Genetics of human complement component C4 and evolution the central MHC

The two classes of human complement component C4 proteins C4A and C4B manifest differential chemical reactivities and binding affinities towards target surfaces and complement receptor CR1. There are multiple, polymorphic allotypes of C4A and C4B proteins. A complex multiplication pattern of C4A and C4B genes with variations in gene size, gene dosage and flanking genes exists in the population. This is probably driven by the selection pressure to respond to a great variety of parasites efficiently and effectively, which the bony fish achieved through the multiplication and diversification of the related complement C3 proteins. Complement C4, C3 and C5 belong to the alpha2 macroglobulin protein family but acquired specific features that include an anaphylatoxin domain, a netrin (NTR) domain, and stretches of basic residues for proteolytic processings to form multiple chain structures. Complement C3 and C4 are important in the innate immune response as they opsonize parasites for phagocytosis. The emergence of complement C3 predates proteins involved in the adaptive immune response as C3 is present in deuterostome invertebrates such as echinoderms. The human C4 genes are located in the central MHC at chromosome 6p21.3. C3 and C5 are located at chromosome 19 and 9, respectively, with representatives of the other groups of genes paralogous to the MHC at 19p13.1-p13.3, 1q21-25, and 9q33-34. The central MHC also contains genes for complement components C2 and Bf. These genes appear to have similar evolutionary histories to C3/C4/C5 and are used here to illustrate stepwise processes resulting in co-location of diverse domains, chromosomal duplication, local segmental duplication and divergence of sequence and function. This model of evolution is useful in the investigation of innate and acquired immunity and in seeking explanations for diseases associated with MHC ancestral haplotypes.

A comparison of elevated blood lead levels among children living in foster care, their siblings, and the general population

OBJECTIVES

To assess the prevalence of elevated blood lead levels (EBLLs) among children before and after foster care placement, and to compare the prevalence of EBLLs among children in foster care with that of their siblings and the general population.

METHODS

We conducted a retrospective cohort study using administrative databases from the Philadelphia Department of Human Services and the Birth Certificate Registry and the Childhood Lead Poisoning Prevention Program at the Philadelphia Department of Public Health. Logistic regression analyses were performed to control for confounding variables, including age, race, gender, and the year, seasonal timing, and source (capillary vs venous) of test.

RESULTS

From June 1992 to May 1997, there were 1824 children in foster care with available blood lead results in the Childhood Lead Poisoning Prevention Program database. Of these, 519 (28%) had initial lead screening before foster care placement and 654 (36%) after placement. There were 821 siblings and 73 608 children in the general population with available blood lead results. Before entering foster care, children were nearly twice as likely to have EBLLs as their siblings (adjusted odds ratio [OR] = 1.7; 95% confidence interval [CI] = 1.4, 2.0), those in placement (adjusted OR = 1.9; 95% CI = 1.6, 2.2), and the general population (adjusted OR = 1.7; 95% CI = 1.5, 2.0). At the highest point prevalence, 50% of children before placement had lead levels >/=20 microg/dL, and nearly 90% had levels >/=10 microg/dL. For all age categories, siblings of children in foster care placement had a higher prevalence of EBLLs than did the general population. After placement, children in foster care were nearly half as likely as the other groups to have EBLLs.

CONCLUSIONS

Our findings suggest that children are at high risk for lead poisoning before entering foster care and that placement in foster care may have a beneficial effect on lead exposure. Children before foster care placement are nearly twice as likely to have EBLLs compared with children in foster care placement, the general population, and their siblings. Furthermore, siblings of children in foster care are at high risk for lead poisoning. Children receiving social services in their own homes and children suffering from abuse and neglect should be actively screened for lead poisoning. Greater efforts at preventing lead poisoning among these children must be made.

Genetic, structural and functional diversities of human complement components C4A and C4B and their mouse homologues, Slp and C4

The complement protein C4 is a non-enzymatic component of the C3 and C5 convertases and thus essential for the propagation of the classical complement pathway. The covalent binding of C4 to immunoglobulins and immune complexes (IC) also enhances the solubilization of immune aggregates, and the clearance of IC through complement receptor one (CR1) on erythrocytes. Human C4 is the most polymorphic protein of the complement system. In this review, we summarize the current concepts on the 1-2-3 loci model of C4A and C4B genes in the population, factors affecting the expression levels of C4 transcripts and proteins, and the structural, functional and serological diversities of the C4A and C4B proteins. The diversities and polymorphisms of the mouse homologues Slp and C4 proteins are described and contrasted with their human homologues. The human C4 genes are located in the MHC class III region on chromosome 6. Each human C4 gene consists of 41 exons coding for a 5.4-kb transcript. The long gene is 20.6 kb and the short gene is 14.2 kb. In the Caucasian population 55% of the MHC haplotypes have the 2-locus, C4A-C4B configurations and 45% have an unequal number of C4A and C4B genes. Moreover, three-quarters of C4 genes harbor the 6.4 kb endogenous retrovirus HERV-K(C4) in the intron 9 of the long genes. Duplication of a C4 gene always concurs with its adjacent genes RP, CYP21 and TNX, which together form a genetic unit termed an RCCX module. Monomodular, bimodular and trimodular RCCX structures with 1, 2 and 3 complement C4 genes have frequencies of 17%, 69% and 14%, respectively. Partial deficiencies of C4A and C4B, primarily due to the presence of monomodular haplotypes and homo-expression of C4A proteins from bimodular structures, have a combined frequency of 31.6%. Multiple structural isoforms of each C4A and C4B allotype exist in the circulation because of the imperfect and incomplete proteolytic processing of the precursor protein to form the beta-alpha-gamma structures. Immunofixation experiments of C4A and C4B demonstrate > 41 allotypes in the two classes of proteins. A compilation of polymorphic sites from limited C4 sequences revealed the presence of 24 polymophic residues, mostly clustered C-terminal to the thioester bond within the C4d region of the alpha-chain. The covalent binding affinities of the thioester carbonyl group of C4A and C4B appear to be modulated by four isotypic residues at positions 1101, 1102, 1105 and 1106. Site directed mutagenesis experiments revealed that D1106 is responsible for the effective binding of C4A to form amide bonds with immune aggregates or protein antigens, and H1106 of C4B catalyzes the transacylation of the thioester carbonyl group to form ester bonds with carbohydrate antigens. The expression of C4 is inducible or enhanced by gamma-interferon. The liver is the main organ that synthesizes and secretes C4A and C4B to the circulation but there are many extra-hepatic sites producing moderate quantities of C4 for local defense. The plasma protein levels of C4A and C4B are mainly determined by the corresponding gene dosage. However, C4B proteins encoded by monomodular short genes may have relatively higher concentrations than those from long C4A genes. The 5' regulatory sequence of a C4 gene contains a Spl site, three E-boxes but no TATA box. The sequences beyond--1524 nt may be completely different as the C4 genes at RCCX module I have RPI-specific sequences, while those at Modules II, III and IV have TNXA-specific sequences. The remarkable genetic diversity of human C4A and C4B probably promotes the exchange of genetic information to create and maintain the quantitative and qualitative variations of C4A and C4B proteins in the population, as driven by the selection pressure against a great variety of microbes. An undesirable accompanying byproduct of this phenomenon is the inherent deleterious recombinations among the RCCX constituents leading to autoimmune and genetic disorders.

Routine and influenza vaccination rates in children with asthma

BACKGROUND

Children with asthma may be at increased risk for low immunization rates given that they have recurrent illnesses that often result in acute care visits to their pediatrician, visits to the emergency room, admissions to the hospital, and visits to subspecialists, where immunizations are not routinely administered.

OBJECTIVES

To assess immunization rates for routine and influenza vaccines in children with asthma and assess factors that may contribute to delay.

METHODS

We conducted a cross-sectional survey of 117 children aged 6 to 48 months with onset of asthma within the first 15 months of life. Subjects were recruited from an allergy and immunology clinic at an urban, tertiary care center. Those judged to have immunization delay did not have the required 4 DTP, 3 OPV, and 1 MMR vaccine by age 24 months (4:3:1 series). Receipt of influenza vaccine was determined for eligible children with moderate to severe asthma.

RESULTS

Seventy-four (80%) children had up-to-date immunizations at age 24 months. Those with delay had fewer visits to a subspecialist than those who were up-to-date (1 versus 2 visits P = .010). Twenty-two (25%) of 87 eligible subjects received influenza vaccine. Recipients were more likely to have been hospitalized than nonrecipients (77% versus 49%, P = .022).

CONCLUSIONS

Though the majority of young children with asthma were up-to-date for routine immunizations, only 25% of children with moderate to severe asthma received influenza vaccine. Greater efforts must be made by pediatricians and asthma subspecialists to ensure that children with moderate to severe asthma are immunized against influenza virus.

Immunogenicity of hepatitis B vaccine in preterm infants

OBJECTIVE

To determine the immunogenicity of hepatitis B vaccine in preterm infants when the first dose of vaccine is delayed until hospital discharge.

METHODS

One hundred two preterm infants (23 to 36 weeks gestational age) born to hepatitis B surface antigen-negative mothers were enrolled. Immunization was initiated just before hospital discharge with subsequent doses 1 and 6 months later. Serum specimens were obtained before the administration of each vaccine dose and 3 months after the last dose and were tested for antibody to hepatitis B surface antigen (antiHBs).

RESULTS

Eighty-seven infants (85%) completed the study. Ninety percent (n = 78) of infants who completed the study seroconverted (antiHBs > or = 10 mIU/mL); 10% (n = 9) remained seronegative at study completion. The geometric mean antibody titer to hepatitis B surface antigen for infants who seroconverted was 200 mIU/mL. Nonresponders (NR) differed from responders (R) in birth weight (NR = 2090 g, R = 1560 g) gestational age (NR = 33 weeks, R = 31 weeks), and weight gain before vaccine initiation (NR = 244 g, R = 633 g). There were no differences in weight or age at vaccine initiation, Apgar scores, interval between vaccine doses, or bacterial infections, steroid use, or transfusions before vaccine initiation.

CONCLUSIONS

Ninety percent of preterm infants responded to hepatitis B vaccine when the first dose of vaccine was delayed until hospital discharge. Nonresponders were more likely to be preterm infants of higher birth weight and higher gestational age, and to have gained less weight before vaccine initiation.

Calcipotriol (MC 903), a synthetic derivative of vitamin D3 stimulates differentiation of squamous carcinoma cell line in the raft culture

We investigated whether calcipotriol, a synthetic derivative of vitamin D3 has the ability to correct defects in the control of proliferation and differentiation of human squamous carcinoma cells using the raft culture of SCC 13 cell line. Calcipotriol treatment at concentrations of 10(-8)-10(-6) M considerably enhanced terminal differentiation of SCC 13 cells, as shown by the appearance of enucleated-eosinophilic cells as well as granular cells in their upper cell layers. Immunohistochemical staining showed marked increases in the differentiation of marker proteins such as keratin 1, involucrin, or filaggrin expressing cells in their upper layers. The elevated expression at protein level was confirmed by immunoblotting analysis. Furthermore, calcipotriol also stimulated basal cell marker proteins such as keratin 14 and EGF receptor. However, the numbers of basal marker expressing cells within the architecture of SCC 13 raft culture were markedly reduced upon calcipotriol treatment, and their localization was mainly restricted in the innermost cell layer. In addition, calcipotriol stimulated EGF receptor biosynthesis for the first 16 hours post treatment and subsequently inhibited [3H]-thymidine incorporation of SCC 13 cells at 24 hours. In this study, we have clearly demonstrated that the long term application of calcipotriol considerably improves the complex defects in the regulation of proliferation and differentiation of SCC 13 cells, as supported by morphological and biochemical observations. This provides an evidence that calcipotriol can be applied clinically as a potent differentiation inducer in the treatment of human squamous cell carcinoma.

False-positive reversible perfusion defect during dobutamine-thallium imaging in left bundle branch block

In the presence of pre-existing left bundle branch block (LBBB) exercise stress thallium scans have been associated with false-positive septal and apical perfusion abnormalities. Recent reports have documented a lower incidence of false-positive septal perfusion defects when pharmacologic agents such as dipyridamole or adenosine are utilized in patients with LBBB. Dobutamine, a synthetic catecholamine, is being used with increasing frequency in combination with perfusion agents for the diagnosis of coronary artery disease in patients unable to achieve an adequate exercise workload. Because the positive inotropic and chronotropic actions of doubtamine are similar to the physiologic effects of treadmill exercise, it is conceivable that false-positive perfusion abnormalities will be observed in patients with pre-existing LBBB undergoing dobutamine perfusion imaging. We describe a patient with underlying LBBB who underwent dobutamine thallium imaging which revealed septal and periapical defects. Subsequent coronary angiography showed these abnormalities to be false-positive. It is concluded that septal and periapical perfusion abnormalities during dobutamine thallium imaging may be false-positive and should be interpreted cautiously.

ST-segment depression during adenosine infusion as a predictor of myocardial ischemia

The incidence and hemodynamic changes associated with ST-segment depression during adenosine stress testing are poorly defined. To examine this, 550 consecutive patients who underwent adenosine perfusion testing were evaluated for the development of ST-segment depression. At least 1 mm of horizontal or downsloping depression developed in 82 patients (15.9%) and was observed with similar frequency in patients with normal scans and those with only fixed defects. ST depression developed in 58 of 242 patients with reversible defects (sensitivity = 24%) and in only 24 of 275 patients without reversible defects (specificity = 91%). Its presence was highly predictive of reversible perfusion defects (predictive accuracy = 71%). Similar findings were observed in patients with and without ECG evidence of left ventricular hypertrophy. Patients with ST depression had perfusion defects in more vessel distributions, had more severe defects, and had a greater increase in heart rate during adenosine infusion. Thus ST-segment depression occurs infrequently during adenosine infusion but is specific for and predictive of myocardial ischemia, as evidenced by reversible perfusion scan defects. Patients with ST depression have more severe disease and develop faster heart rates during infusion, which could result in decreased coronary perfusion during diastole allowing for the development of myocardial ischemia.

Schizophrenic delusions among Koreans, Korean-Chinese and Chinese: a transcultural study

In this transcultural study of schizophrenic delusions among Koreans, Korean-Chinese and Chinese, many delusions were shown to be different among the three groups in their frequency and content and the differences could be explained by sociocultural and political factors. Delusional themes sensitive to influence by sociocultural or political situations and changes seem to be 'family', 'love affairs', 'religious matters', 'economic matters', 'specific physical damage' and 'political themes.' Delusions about 'family', 'love affair', 'being raped', 'religious matters' and 'economic and business matters' were most frequent in Koreans. Delusions of 'blood-relatedness', 'longevity' and 'political themes' were most frequent in Korean-Chinese. Delusions of 'bloodsucking and brain or viscera extracted' and 'poison or being pricked by poisoned needle' were most prominent in Chinese.

Abnormal thallium-201 scans in patients with chest pain and angiographically normal coronary arteries

We reviewed the exercise thallium-201 (TI-201) scans and clinical data of 41 patients with chest pain and normal coronary arteries to identify clinical factors associated with "false-positive" studies. Exercise TI-201 studies were performed before angiography and often precipitated referral. Sex, beta-blocker therapy, anginal pattern, and results of exercise electrocardiography were evaluated and compared with TI-201 imaging. A negative TI-201 study was the most common finding (p less than 0.005). Of the 41 patients, 11 (27%) had abnormal exercise TI-201 scans. No clinical factor was significantly associated with a false-positive TI-201 scans. Of the 11 patients with abnormal scans, 9 had greater than or equal to 1 cardiac abnormality: right bundle branch block in 2, mitral valve prolapse in 3, paroxysmal atrial fibrillation in 2, abnormal left ventricular diastolic pressure in 3, and left bundle branch block in 1. Thus, (1) when results of exercise TI-201 imaging are used to refer patients for angiography, "false-positive" TI-201 studies are common; (2) sex, beta blockade, anginal pattern, and results of exercise electrocardiogram are not useful predictors of a false-positive TI-201 study; and (3) patients with chest pain, normal coronary arteries, and abnormal TI-201 scans frequently have other cardiac abnormalities.

Clinical implication of surface morphology of ventricular premature contractions

VPC morphology was studied in the surface 12-leads ECGs (resting) in one hundred and thirty-six patients over a none-month period (January-September, 1978). Seventy four (54%) of these had coronary artery disease proven by cardiac catheterization (61) or by evidence of acute transmural myocardial infarction (13) diagnosed by ECG and serum enzyme study. Twenty-three of the patients (17%) had other organic heart diseases documented by cardiac catheterization. The remaining thirty-nine (29%) were healthy individuals. Three common types of VPCs are recognized as right, left and septal in origin. There is no significant difference in the prevalence of these types in the presence of heart disease (right, 35%, left 31%, and septal 34%). However if septal VPCs are considered along with left VPCs, these are twice as common as right VPCs. VPCs occurring in healthy individuals are overwhelmingly (74%) right ventricular in origin. In general, VPCs are most likely to occur in the presence of ventricular dyssynergy and multiple coronary arterial lesions.

Pseudomyocardial infarction associated with acute bifascicular block due to hyperkalemia

A case with lymphocytic lymphoma showing unusual ECG findings consisting of pseudoacute anteroseptal myocardial infarction associated with acute bifascicular block (a combination of right bundle branch block and left anterior hemiblock) secondary to hyperkalemia is presented. To our knowledge, this is the first reported case showing such unusual hyperkalemia-induced ECG abnormalities. No evidence of myocardial infarction (acute or old) was found in this case on the post-mortem examination. The importance of recognizing pseudomyocardial infarction in hyperkalemia is emphasized to distinguish from true myocardial infarction. In addition, it has been stressed that hyperkalemia is one of the important causes of acute bifascicular block.

Runaway pacemaker. Unpredictable pacemaker failure

The runaway pacemaker is an uncommon but very serious complication of permanent artificial pacemakers. Although the runaway pacemaker has been most frequently encountered in older (fixed rate) pacemakers, this problem has also been reported in various types of newer models manufactured by different companies. The most striking finding in our case is that the pacemaker was reported by a reliable pacemaker follow-up service to be working normally only one week before the development of the malfunction. The extremely rapid pacing rate (750 beats per minute) was a manifestation of a far-advanced runaway pacemaker. The manufacturer believes that this is the first reported incident of a runaway pacemaker in this model. This indicates that the runaway pacemaker is still a potential problem, even in newer pacemakers, and reemphasizes the unpredictable and serious nature of this medical emergency.

Ventricular fibrillation in Wolff-Parkinson-White syndrome, type A

A young individual who developed ventricular fibrillation following atrial fibrillation in the WPW syndrome is presented. The precise cardiac rhythm diagnosis is extremely important for proper management. When the QRS morphology is bizarre and the ventricular rate is very fast (200 to 300 b.p.m.) in atrial fibrillation, the WPW syndrome should be considered as the underlying disorder. Digitalis should be avoided in this circumstance because anomalous conduction may be accelerated by the drug, leading to deterioration of the clinical picture and even death. When an antiarrhythmic drug is to be used, intravenous lidocaine is the drug of choice. For the prophylactic measure, oral quinidine or procainamide is equally effective for atrial fibrillation with anomalous conduction in the WPW syndrome.

Sick sinus syndrome due to cardiac amyloidosis

In a patient suffering from cardiac amyloidosis a case of sick sinus syndrome, manifested by markedly prolonged recovery time of the sinus node, was documented by an atrial pacing study. The first A-V junctional escape interval was markedly prolonged following the termination of the atrial pacing, pointing to a coexisting A-V nodal dysfunction. The patient required a permanent artificial pacemaker implantation.

Drug-induced cardiovascular diseases

A wide variety of drugs may be associated with serious cardiovascular toxicity. Toxicity due to drugs primarily used for treating cardiovascular toxicity. Toxicity due to drugs primarily used for treating cardiac disorders is the most extensively documented, especially the arrhythmias due to digitalis glycosides. Various arrhythmias are also caused by toxic levels of many antiarrhythmic agents including quinidine, procainamide and phenytotin. Myocardial depression and heart failure are serious side-effects of beta-adrenoceptor blocking agents and myocardial ischaemia due to sympathominetic amines may result from both direct and indirect mechanisms. The many toxic reactions in the cardiovascular system due to non-cardiac drugs are less widely known and for the most part less clearly understood. Many remain controversial at the current time; for example, the diathesis toward thromboembolism in women taking oral contraceptives. Potential cardiac toxicity due to drugs used in the rapidly expanding sphere of anti-neoplastic chemotherapy is exemplified by the cardiomyopathy-like toxicities of doxorubicin and daunorubicin. Many of the psychotherapeutic drugs including phenothiazine antipsychotics and tricyclic antidepressants have arrhythmogenic potential.

Acute myocardial infarction following fluorescein angiography

A 64-year-old woman with diabetes mellitus as well as hypertensive retinopathy developed an acute myocardial infarction and hypertensive crisis following the injection of 5 ml. of 10 per cent sodium fluorescein for fundus angiography. This is the first time this complication has been documented. Possible mechanisms for such an occurrence are discussed. Recommendations for recognizing and dealing with patients at high risk for cardiovascular complications of fluorescein angiography are emphasized.

Wolff-Parkinson-White Syndrome--current views

The Wolff-Parkinson-White (WPW) syndrome is an important clinical entity because of frequent recurrences of very rapid tachyarrhythmias. The electrocardiographic finding of the WPW syndrome often mimicks pseudo diaphragmatic (inferior) myocardial infarction which should not be misinterpreted. The most important diagnostic criterion is recognition of a delta wave; the short P-R interval or broad QRS complex may not be present in every case. The mechanism for the tachycardia is considered to be a reentry phenomenon via anomalous and normal atrioventricllar (A-V) pathways. The drug of choice for the treatment of regular supraventricular (reciprocating) tachycardia with narrow QRS complexes, which is the most common arrhythmia in the WPW syndrome, is propranolol. Digitalis is almost equally effective in this case. For tachyarrhythmias, particularly atrial fibrillation or flutter with anomalous conduction, intravenously-administered lidocaine is considered to be the drug of choice. Procainamide or quinidine is also frequently used under this circumstance with excellent therapeutic result. Many patients with the WPW syndrome require long-term maintenance drug therapy (propranolol, digitalis or quinidine in most cases). In urgent clinical situations, direct current (DC) shock should be applied immediately. In selected patients with refractory tachyarrhythmias, the use of an artificial pacemaker or surgical approach may be considered.

Ventricular pseudo-bigeminy due to sustained myoclonus

An elderly unconsciocus patient with anteroseptal myocardial infarction showing ventricular pseudo-bigeminy (artifact) due to sustained myoclonus is reported. The reason why the artifacts coincided with his cardiac contraction is not clearly understood. The artifact is completely eliminated following intravenous injection of succinylcholine chloride. This is the first reported case of such a puzzling electrocardiographic finding to our knowledge. It is extremely important to distinguish between a true and pseudo-arrhythmia. Otherwise, an erroneous diagnosis frequently leads to an erroneous therapeutic approach.

Unusual electrocardiographic finding--bifascicular block due to hyperkalemia

A unique case in which the patient had bifascicular block consisting of right bundle branch block and left posterior hemiblock as a result of marked hyperkalemia is presented. To our knowledge, this is the first reported case in which such unusual electrocardiographic abnormalities due to hyperkalemia were demonstrated. The electrocardiographic abnormalities produced by hyperkalemia in this case disappeared promptly by hemodialysis, as the serum potassium level returned to normal. It has been stressed that hyperkalemia should be considered as an important etiologic factor in the differential diagnosis of bundle branch block, hemiblocks and bifascicular block, particularly when these intraventricular blocks are produced suddenly.

Artificial cardiac pacing: 2. follow-up and complications

Following insertion or implantation of an artificial cardiac pacemaker, both physician and patient are involved in aftercare to monitor the patient's cardiac status, the condition of the implantation site, and the function of the pacemaker. Among the complications that may occur are pacemaker malfunction and perforation of the ventricles. The physician and patient must also be alert to the possibility of electrical interference and to the physiologic factors that can modify pacemaker function.

Artificial cardiac pacing. 1. Indications

With increasing use of artificial cardiac pacing, criteria for selection of patients have been refined. In general, the most important indication for pacing is the presence and severity of symptoms due to bradyarrhythmias. Use of pacing in acute myocardial infarction remains controversial, but some guidelines are presented here.

Coexisting ventricular and blocked atrial parasystole

A rare instance showing non-conducted atrial parasystole coexisting with ventricular parasystole is presented and a related subject is briefly discussed. The importance of recognizing parasystole is again emphasized because the ordinary extrasystoles, particularly ventricular in origin, are frequently digitalis-induced, while parasystole, which superficially resembles the ordinary extrasystoles, does not seem to be related to digitalis.

Reciprocal beats initiated by artificial pacemaker

In conclusion, the underlying mechanism for this rhythm disturbance in our patient is the re-entry phenomenon, which is dependent upon a localized unidirectional block in the A-V junction. The predisposing factors, including digoxin and Inderal which tend to prolong A-V conduction, are considered for the mechanism of the production of the reciprocal beats in our case. Upon temporary withdrawal of digoxin and Inderal, the re-entry phenomenon has disappeared.

Pacemaker bigeminy: pseudomalfunction

The first reported unique case of atrial synchronized pacemaker-induced bigeminy is described and related literature is briefly discussed. The arrhythmia reported in this case can be erroneously misinterpreted as a malfunctioning pacemaker unless the physician is fully familiar with the specific nature of the atrial synchronized pacemaker. By recognizing this type of pacemaker bigeminy as an arrhythmia simply related to a normally functioning pacemaker, unnecessary surgery can be avoided.

Reappraisal of hemiblock

The left bundle branch separates into the left anterior and the left posterior divisions. The impulse travels to the left ventricle via both divisions when they are intact. When one division is blocked, the diagnosis is hemiblock. Diagnostic criteria for left anterior hemiblock are marked left axis deviation, small Q wave in lead I and small R wave in lead III, little or no prolongation of the QRS interval, and no evidence of other causes of left axis deviation. Criteria for left posterior hemiblock are marked right axis deviation, small R wave in lead I and small Q wave in lead III, little or no prolongation of the QRS interval, and no evidence of other causes of right axis deviation. A pure form of hemiblock is not uncommon, especially during acute anterior myocardial infarction, but right bundle-branch block often coexists with hemiblock. Like left bundle-branch block, hemiblocks rarely occur in healthy persons. They are commonly associated with coronary or hypertensive disease or both and are less commonly associated with cardiomyopathies and calcified aortic disease.