Linking childhood trauma and dissociation to psychotic symptoms in major depressive disorder, bipolar disorders, and schizophrenia: A transdiagnostic examination using patient and clinician ratings

OBJECTIVE

Symptomatic overlap between dissociation and psychosis is well documented; however, the pathogenesis of these two phenomena might be distinct. Few studies have analyzed the relation of dissociative and psychotic symptoms transdiagnostically. The current study examines an emerging trauma-dissociation theoretical model that accounts for psychotic symptoms across affective disorders and schizophrenia (SCZ).

METHOD

Psychiatric inpatients with DSM-5 major depressive disorder (MDD), bipolar disorders (BD) currently in a major depressive episode, and SCZ, and healthy controls (HC) were recruited. Potentially traumatizing events in childhood, dissociative symptoms, and psychotic symptoms were assessed. In addition to participant's self-report, dissociative and psychotic symptoms were rated by psychiatrists blind to the hypothesis. Path analysis was conducted.

RESULTS

Dissociation was commonly experienced by clinical participants, particularly for those with MDD or BD. For the SCZ group, ratings of dissociation differed between patient and clinician; specifically, patient-reported dissociation scores, but not clinician-rated scores, were higher than that of the HC group. Importantly, the links between childhood trauma, dissociation, and psychotic symptoms were not homogenous across the diagnostic groups. Dissociation mediated the relationship between childhood trauma and psychotic symptoms in the MDD and BD groups, but not the SCZ group.

CONCLUSION

Depending on the psychiatric condition, dissociation and psychosis have different clinical implications. Childhood trauma and dissociation provide an account for psychotic symptoms in patients diagnosed with MDD and BD, but not with SCZ. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Efficacy of online training at the International Mental Health Training Center Taiwan (IMHTCT): Pre and during the COVID-19 pandemic

STUDY OBJECTIVES

The coronavirus disease 2019 (COVID-19) pandemic has resulted in major disruption to regular learning and training for medical staff. The aim of this study was to compare the learning efficacy between on-site training before the COVID-19 pandemic and online training during the pandemic for nurses, psychologists, social workers, and occupational therapists from Southeast Asia.

METHOD

The current study derived data from the International Mental Health Training Center Taiwan (IMHTCT) from 2018 to 2020. IMHTCT Trainees Learning Effect Questionnaire (ITLEQ) scores of the medical staff and demographic variables were collected. Reliability and validity of the ITLEQ were estimated. The independent t-test was used to compare differences in ITLEQ scores between the pre-training and post-training stages among the trainees. In addition, generalized estimating equations were used to estimate the predictive effect of online training on changes in ITLEQ scores over time.

FINDINGS

A total of 190 trainees were enrolled, including 92 social workers, 16 occupation therapists, 24 psychologists, and 58 nurses. The reliability and validity were satisfactory. The efficacy of the training programs at IMHTCT was significant for all of the healthcare workers. Furthermore, better training efficacy was found in the social workers and occupational therapists who received online training compared to those who received on-site training. The potential efficacy of online training was found in the nurses.

CONCLUSION

Our results demonstrate the importance of online training for mental healthcare workers during the COVID-19 pandemic. Online training may be implemented into regular training courses in the future.

Erroneous Thought in Inpatients with Major Depressive Disorder: The Role of Psychological Trauma During Childhood and Adulthood

BACKGROUND

The pathogenic role of trauma in psychotic-like experiences has yet to be clarified. The aim of this study was to investigate the role of childhood and adulthood trauma on erroneous thoughts among patients with major depressive disorder.

MATERIALS AND METHODS

Inpatients with major depressive disorder (MDD) and healthy controls (HCs) were enrolled, and paper-and-pencil questionnaires were applied. Clinical rating and self-reported scales were used to measure levels of depression, dissociation, psychological trauma, parental maltreatment, and erroneous thoughts. Pearson's correlation analysis was conducted to explore potentially significant associations between erroneous thoughts and other independent variables, and standardized regression coefficients of hierarchical regression analysis were used to predict the significant relationships between erroneous thoughts and adulthood or childhood trauma.

RESULTS

A total of 99 participants were included into the analysis, of whom 59 were patients with MDD and 40 were HCs. After treatment, the patients with MDD showed significantly higher levels of depression, childhood maltreatment, interpersonal trauma and erroneous thoughts than the HCs. After estimating and verifying correlations with hierarchical regression among the patients with MDD, a link between adulthood betrayal trauma and higher level of conviction along with the number of erroneous thoughts was found. However, no significant association was identified between childhood trauma and erroneous thought. The concurrent level of depression significantly predicted a higher level of being preoccupied, along with the number of erroneous thoughts.

CONCLUSION

The current study fills a gap in the literature by showing a link between adulthood trauma and erroneous thoughts in non-psychotic patients. Further studies with well-controlled comparisons and prospective cohort with longer follow-up are warranted to extend the applicability and generalizability of the current study.

Relationship of Societal Adaptation with Vaccine Worries among Healthcare Workers during the COVID-19 Pandemic: The Mediating Effects of Posttraumatic Stress Disorder

Vaccine hesitancy has become a major public health problem among healthcare workers (HCWs) in this coronavirus disease 2019 (COVID-19) pandemic. The aim of this study was to examine the relationship between societal adaptation and vaccine worries and the mediating effects of posttraumatic stress disorder (PTSD) indicators in HCWs. A total of 435 HCWs (327 women and 108 men) were recruited. Their levels of societal adaptation were evaluated using the Societal Influences Survey Questionnaire (SISQ). Their severity and frequency of PTSD symptoms were examined using the Disaster-Related Psychological Screening Test (DRPST). The severity of vaccine worries was assessed using the Vaccination Attitudes Examination (VAX) Scale. The relationships among societal adaptation, PTSD, and vaccine worries were examined using structural equation modeling. The severity of societal adaptation was positively associated with both the severity of PTSD and the severity of vaccine worries. In addition, the severity of PTSD indicators was positively associated with the severity of vaccine worries. These results demonstrated that the severity of societal adaptation was related to the severity of vaccine worries, either directly or indirectly. The indirect relationship was mediated by the severity of PTSD. Societal adaptation and PTSD should be taken into consideration by the community of professionals working on vaccine hesitancy. Early detection and intervention of PTSD should be the objectives for programs aiming to lower vaccine hesitancy among HCWs.

The moderation of maternal parenting on the association of trauma, dissociation, and psychosis in depressive inpatients

BACKGROUND

The effect of dissociation and parenting style on the relationship between psychological trauma and psychotic symptoms has not previously been investigated.

OBJECTIVE

The aim of this study was to develop a moderated mediation model to assess whether the association between psychological trauma and psychotic symptoms is mediated by dissociation and moderated by parental maltreatment.

METHODS

Inpatients with major depressive disorder (MDD) and bipolar depression (BP) were recruited. Self-reported and clinical rating scales were used to measure the level of dissociation, psychotic symptoms, history of psychological trauma and parental maltreatment. The PROCESS macro in SPSS was used to estimate path coefficients and adequacy of the moderated mediation model. High betrayal trauma (HBT), low betrayal trauma (LBT), paternal maltreatment, and maternal maltreatment were alternatively entered into the conceptual model to test the adequacy.

RESULTS

A total of 91 patients (59 with MDD and 32 with BP) were recruited, with a mean age of 40.59 ± 7.5 years. After testing with different variables, the moderated mediation model showed that the association between LBT and psychotic symptoms was mediated by dissociation and moderated by maternal maltreatment. A higher level of maternal maltreatment enhanced the effect of LBT on dissociation.

CONCLUSIONS

Healthcare workers should be aware of the risk of developing psychotic symptoms among depressive patients with a history of LBT and maternal maltreatment.

The Societal Influences and Quality of Life Among Healthcare Team Members During the COVID-19 Pandemic

Background: The coronavirus infection disease 2019 (COVID-19) pandemic is likely to put healthcare professionals across the world in an unprecedented situation. Methods: A total of 683 healthcare workers were recruited in this study. Short form-12 items (SF-12), Societal Influences Survey Questionnaire (SISQ), and Disaster-Related Psychological Screening Test (DRPST) were used to survey participants. Multiple linear regression and structural equation model (SEM) were used to explore the possible factors to the societal influences and quality of life. Results: After multiple linear regression analysis, female, older, more education years, married, regular intake, and posttraumatic stress disorder (PTSD) frequency had positive association with SISQ. To physical component summary (PCS) of SF-12, chronic illness, sleep score, PTSD frequency, and social distance had negative association, and exercise habits had positive association. A mental component summary (MCS) value of SF-12, age, participate in social activities, and social information had positive association, and PTSD frequency, sleep score, social anxiety, and depression had negative association. Under SEM analysis, PTSD had positive influence on SISQ. Sleep score and MCS value had negative influences on SISQ. PTSD severity, older age, sleep score, smoking, and nursing staff had negative influences on PCS value. Young age, PTSD frequency, sleep score, and depression had negative influences on MCS value. Conclusion: Healthcare team members with severe PTSD symptoms suffered more societal influences. Relative to PTSD severity, PTSD frequency was more important to the quality of life. Members of older age who frequently participate in clubs, volunteers, or charity activities had better mental life quality.

Mental health in biological disasters: From SARS to COVID-19

BACKGROUND

The outbreak of coronavirus disease 2019 (COVID-19), like severe acute respiratory syndrome (SARS), provokes fear, anxiety and depression in the public, which further affects mental health issues. Taiwan has used their experience of the SARS epidemic for the management of foreseeable problems in COVID-19 endemic.

AIM/OBJECTIVE

This review summarizes issues concerning mental health problems related to infectious diseases from current literatures.

RESULTS

In suspected cases under quarantine, confirmed cases in isolation and their families, health care professionals, and the general population and related effective strategies to reduce these mental health issues, such as helping to identify stressors and normalizing their impact at all levels of response as well as public information and communication messages by electronic devices. The importance of community resilience was also addressed. Psychological first aid, psychological debriefing, mental health intervention and psychoeducation were also discussed. Issues concerning cultures and religions are also emphasized in the management plans.

CONCLUSION

Biological disaster like SARS and COVID-19 not only has strong impact on mental health in those being infected and their family, friends, and coworkers, but also affect wellbeing in general public. There are evidenced that clear and timely psychoeducation, psychological first aid and psychological debriefing could amileorate negative impact of disaster, thus might also be helpful amid COVID-19 pandemic.

Challenge and strategies of infection control in psychiatric hospitals during biological disasters-From SARS to COVID-19 in Taiwan

Psychiatric hospitals play an important role in supporting patients with mental illness to relieve symptoms and improve functioning in a physically and psychologically safe environment. However, these hospitals are also vulnerable to emerging infectious diseases. In early 2020, a psychiatric hospital and a psychiatric unit were reported to have nosocomial coronavirus disease 2019 (COVID-19) infection. A large number of patients and staff were severely impacted. This type of nosocomial infection threatens patient safety and quality of care. By learning from previous experiences of severe acute respiratory syndrome (SARS) and previous studies, psychiatric hospitals can provide safeguards to prevent nosocomial infection among patients and staff during an epidemic or biological disaster. These strategies include a series of actions such as following national guidelines for infection control, reserving adequate support for disinfection equipment, providing relevant and sufficient pro-service and in-service education and training, establishing regular surveillance of hand hygiene habits, proper communication and health education, and providing opportunities for vaccination if possible. Based on the harm reduction concept, staff division of office breaks and ward classification and shunting are recommended and should be further implemented.

From folk therapy to evidence-based psychiatry practice: The benefit of evidence-based psychiatry in treatment-naive psychotic patients

BACKGROUND

As Taiwan's Mental Health Act (MHA) clearly states that the human rights and legal rights of psychotic patients should be respected and guaranteed; however, a temple asylum violates the law in the 21st century. Hundreds of patients were constrained in the asylum for years without consent. Because of outbreak of infectious diseases, patients were evacuated from the asylum by the official intervention.

AIMS

To evaluate the outcomes of these patients from folk therapy to conventional treatment.

METHOD

The study recruited the drug-naive psychotic patients constrained in an asylum for decades. Before and after the formal treatment, 253 patients were diagnosed with schizophrenia and other psychotic disorders with assessment of using the Mini Positive and Negative Syndrome Scale (Mini-PANSS) and Comprehensive Occupational Therapy Evaluation (COTE) scale. In addition, family function, self-care ability and nutritional status were also evaluated.

RESULTS

The initial data show the improvement in psychotic symptoms and occupational function in these patients. Furthermore, the ratio of patients who were classified as being at risk for malnutrition was decreased by 21.7% after treatment. There was no statistically significant difference in self-care ability before and after treatment.

CONCLUSION

The psychotic symptoms and occupational function of these patients were improved after the formal treatment compared to the folk therapy. The care model for the psychotic patients in the temple asylum should be more thoroughly discussed in consideration of the medical ethics principles.

Serum folate levels in bipolar disorder: a systematic review and meta-analysis

BACKGROUND

Bipolar disorder (BD) is a major psychiatric illness, however its physiopathology is unclear. The role of folate in the physiopathology of BD is controversial. We conducted this systematic review and meta-analysis to investigate the effect of folate in BD patients.

METHODS

We performed a thorough literature study of the PubMed, Embase, ScienceDirect, ClinicalKey, Cochrane Library, ProQuest, Web of Science, and ClinicalTrials.gov databases until December 21st, 2018. Random effects meta-analysis was conducted.

RESULTS

Six articles involving 481 patients with BD and 760 controls were included. The meta-analysis results suggested that serum folate levels in the patients with BD were significantly lower than those in the controls (Hedges' g = - 0.211, 95% confidence interval = - 0.391 to - 0.031, p = 0.021).

CONCLUSION

The current meta-analysis show it might be association between lower serum folate levels and patient with BD. However, we could not distinguish the potentially confounding effects of mood states on the folate levels. Further prospective studies including subjects with different mood states and possible physiopathology are warranted to investigate the association between folate deficiency and the etiology of BD.

Do baseline WAIS-III subtests predict treatment outcomes for depressed inpatients receiving fluoxetine?

This study aimed to determine whether baseline WAIS-III subtests could be associated with treatment outcomes for patients with major depressive disorder (MDD) receiving a 6-week fluoxetine treatment. A total of 131 acutely ill MDD inpatients were enrolled to receive 20 mg of fluoxetine daily for 6 weeks. Eight WAIS-III subtests were administered at baseline. Symptom severity and functional impairment were assessed at baseline, and again at weeks 1, 2, 3, 4, and 6 using the 17-item Hamilton Depression Rating Scale (HAMD-17) and the Modified Work and Social Adjustment Scale (MWSAS), respectively. The generalized estimating equations method was used to analyze the influence of potential predictors over time on the HAMD-17 and MWSAS, after adjusting for covariates. Of the 131 participants, 104 (79.4%) who completed 8 WAIS-III subtests at baseline and had at least one post-baseline assessment were included in the analysis. Patients with lower forward digit span scores were more likely to have poor treatment outcomes, both measured by HAMD-17, and by MWSAS. Forward digit span may be clinically useful in identifying MDD patients with greater treatment difficulty in symptoms and functioning. Other neurocognitive tests to predict treatment outcome require further exploration.

Employing crisis postcards with case management in Kaohsiung, Taiwan: 6-month outcomes of a randomised controlled trial for suicide attempters

BACKGROUND

Suicide attempts constitute a serious clinical problem and have important implications for healthcare resources. The aim of the present study was to evaluate the effectiveness of case management using crisis postcards over a 6-month follow-up period.

METHOD

A randomised controlled trial was conducted in Kaohsiung, Taiwan. Prevention of further suicide attempts was compared between two groups with and without the postcard intervention. The intervention group consisted of 373 participants (139 males, 234 females; age: 39.8 ± 14.0 yrs.). The control group consisted of 388 participants (113 males, 275 females; age: 40.0 ± 16.0 yrs.). A survival analysis was used to test the effectiveness of the crisis postcard intervention for the prevention of suicide reattempts. Per-protocol and intention-to-treat analyses were conducted.

RESULTS

The intention-to-treat analysis indicated that the crisis postcard had no effect (hazard ratio = 0.84; 95% CI = 0.56 - 1.29), whereas the per-protocol analysis showed a strong benefit for the crisis postcard (hazard ratio = 0.39; 95% CI = 0.21 - 0.72).

CONCLUSION

Although the results of the present study indicated that the postcard intervention did not reduce subsequent suicide behaviour, our study provides an alteration to the postcard intervention. Further studies need to be conducted to clarify whether this type of intervention can reduce subsequent suicidal behaviour, with a particular focus on reducing the rate of loss to follow-up.

Early prediction of clinical response in schizophrenia patients receiving the atypical antipsychotic zotepine

OBJECTIVE

Prior early prediction models for antipsychotic treatment response demonstrate good specificity but poor sensitivity (i.e., high false-negative rates). The purpose of this study was to refine the early prediction model in schizophrenia patients taking an atypical antipsychotic agent, zotepine.

METHOD

135 acutely ill inpatients with DSM-IV-defined schizophrenia received 4 weeks of 150 mg/day zotepine treatment. Psychopathology severity was assessed weekly with the Brief Psychiatric Rating Scale (BPRS) and subscales for positive, negative, and general symptoms. Clinical response was defined as a reduction of 20% or more in the BPRS total score at week 4. A logistic regression model was used to obtain early predictors. The receiver operating characteristic curve was employed to determine the optimal cutoff points of the variables for predicting response. The study was conducted from June 2004 to April 2005.

RESULTS

The most significant early predictors for ultimate response at week 4 were BPRS positive subscale score changes at week 1 and, better, at week 2 (p < .001 at both timepoints). At week 1, a BPRS positive score reduction of 4 appeared to be the optimal cutoff point for predicting eventual response, providing a sensitivity of 0.77 and specificity of 0.77. At week 2, a BPRS positive score reduction of 6 was the best for prediction, with a sensitivity of 0.83 and specificity of 0.91.

CONCLUSIONS

These findings suggest that using the first 2 weeks' improvement in positive symptoms to predict the fourth week's treatment response is favorable in terms of both specificity and sensitivity. Further studies are needed. Moreover, whether this model could be applied to establish a prediction system for other antipsychotics or other psychotropics also deserves research.

The correlation between alteration of p16 gene and clinical status in oral squamous cell carcinoma

The purpose of the study was to evaluate the presence of alteration of the tumor suppressor gene p16 and to correlate these changes with the clinical status of the patients in oral squamous cell carcinoma. Forty-eight oral squamous cell carcinomas were included in the analyses. Deletion analysis was performed by the polymerase chain reaction (PCR). Mutation analysis was restricted to exon 1 and exon 2 of the p16 gene, previously shown to have a high incidence of mutations. The sequences containing exon 1 and exon 2 were amplified by PCR and screened with a single-strand conformation polymorphism (SSCP) technique. Samples showing band shifts in SSCP were sequenced by PCR direct sequencing. Western blots were used to detect the protein expression of the p16 gene, and the results were evaluated with regard to their biological relevance in correlation with clinicopathological factors. Seven (14.6%) deletions were found; 5 (10.4%) mutations were discovered and located in different codons; 26 (54%) specimens had no p16 protein expression; in 11 specimens with p16 deletion or mutation, p16 protein could not be detected. One mutation was non-sense. The p16 gene alterations showed no relationship with location and clinical stage of cancer; however, a close relationship between p16 alterations and cancer metastasis to neck lymph node was found. The alteration rate gradually elevated from well to poorly differentiated grades. We perceive two results. First, the alterations of the p16 gene are common in oral squamous cell carcinoma. Second, the alterations of the p16 gene may attribute to the metastatic behavior or histological grade of cancer cells.

Biofilter treatment of aquaculture water for reuse applications

Biotreatment of aquaculture water for recirculation purposes is a sensible mean to support the further growth of aquaculture industry without excessive water demands that are environmentally unsustainable. This study evaluates the efficacy of biofilter treatment of an eel (Anguilla japonica) culture pond water using different filter media and flow scheme arrangements. The experimental results demonstrate that biofilter systems packed with suitable filter media are capable of improving the quality of effluents for recirculation applications. The characteristics of the filter media appear to be more critical than biofilter flow scheme arrangements in affecting the efficacy of the biofilter treatment. Filter media with surface and structural characteristics are conducive to the development of biofilms and the capture of organic suspended matter are desirable to ensure good and consistent biofilter performance. Under such circumstances the bacterial "consortia" in the biofilter are capable of utilizing the captured organic suspended matter as an alternative substrate to support their metabolic activities when the concentration of the primary substrate (i.e., BOD) is low. For the eel pond water, a biofilter packed with filter media having cross-link structures and a high bed porosity, followed by another biofilter packed with a type of filter media having rough surfaces, produced the best results under the conditions tested. Moreover, a preliminary cost-benefit analysis confirms its cost advantages.

The effect of ankle disk training on muscle reaction time in subjects with a history of ankle sprain

The purpose of this study was to determine whether 8 weeks of ankle disk training alters ankle muscle onset latency of patients with a history of lateral ankle sprain. The training was completed by eight minimally symptomatic subjects with a history of nonrehabilitated, unilateral, inversion ankle sprain sustained between 6 and 16 months before entry into the study. Ankle inversion perturbations monitored by fine-wire electromyography were performed in four lower extremity muscles (anterior tibialis, posterior tibialis, peroneus longus, and flexor digitorum longus) of all subjects on both the injured (experimental) and noninjured (control) legs. Testing was performed at study entry and after 8 weeks of ankle disk training on the previously injured ankle. Results revealed a statistically significant decrease in the anterior tibialis onset latency in both the experimental (67.6 +/- 20.3 to 51.7 +/- 17.6) and control (65.5 +/- 9.8 to 53.8 +/- 23.7) ankles after the training period. These findings indicate that muscle onset latency decreases in specific ankle muscle groups after ankle disk training in previously injured ankles. Both the experimental and control ankles demonstrated a significant change, which raises the question as to whether a proprioceptive cross-training effect occurred.

Motion of the whole body's center of mass when stepping over obstacles of different heights

Tripping over obstacles and imbalance during gait were reported as two of the most common causes of falls in the elderly. Imbalance of the whole body during obstacle crossing may cause inappropriate movement of the lower extremities and result in foot-obstacle contact. Thus, this study was performed to investigate the effect of obstacle height on the motion of the whole body's center of mass (COM) and its interaction with the center of pressure (COP) of the stance foot while negotiating obstacles. Six healthy young adults were instructed to perform unobstructed level walking and to step over obstacles of heights corresponding to 2.5, 5, 10, and 15% of the subject's height, all at a comfortable self-selected speed while walking barefoot. A 13-link biomechanical model of the human body was used to compute the kinematics of the whole body's COM. Stepping over the higher obstacles resulted in significantly greater ranges of motion of the COM in the anterior-posterior and vertical directions, a greater velocity of the COM in the vertical direction, and a greater anterior-posterior distance between the COM and COP. In contrast, the motion of the COM in the medial-lateral direction was less likely to be affected when negotiating obstacles of different heights.

Effects of camphorated parachlorophenol on human periodontal ligament cells in vitro

To date, there has been very little research into the possible effects of endodontic therapy on regeneration of a lost periodontal attachment. The objective of this study was to examine the effects of the endodontic medication, camphorated parachlorophenol (CMCP), on human periodontal ligament cells in vitro. The cytotoxic effects of CMCP were evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide colorimetric assay and cell proliferation using a [3H]thymidine incorporation assay. CMCP inhibited the human periodontal ligament cells viability and proliferation in a dose-dependent manner (p < 0.05). These data indicate that the use of CMCP in a root canal could cause periodontium damage. Although this study was conducted in vitro, the findings suggest that it may not be advisable to use CMCP as an interim medication when a periodontal surgical procedure, especially an attempt at regeneration or a new attachment procedure, is being considered in tissues adjacent to the endodontically involved tooth.

Mitochondrial DNA analysis of sympatric morphotypes of bottlenose dolphins (genus: Tursiops) in Chinese waters

The classification within the bottlenose dolphin (genus Tursiops) is controversial. Although many morphological variants exist, most authors have concluded that the genus is composed of a single species, Tursiops truncatus (Montagu 1821). Two distinct morphotypes of bottlenose dolphins, which have been referred to as T. truncatus and T. aduncus, exist in sympatry in Chinese waters. Comparisons of a 386-bp fragment of the mitochondrial DNA (mtDNA) control region (n = 47) indicated that the two sympatric morphotypes were genetically distinct, with seven fixed site differences and a sequence divergence of approximately 4.4%. Phylogenetic analyses using maximum likelihood, neighbour-joining and maximum parsimony approaches showed that the truncatus-type dolphins from Chinese waters were more closely related to Atlantic Ocean truncatus-type than to the sympatric aduncus-type dolphins. The Atlantic truncatus-type dolphins also shared the same diagnostic sites that separated Chinese truncatus-type from aduncus-type dolphins. The molecular data agreed completely with the morphological classifications of the specimens. This congruence is strong evidence that the sympatric morphotypes in Chinese waters are reproductively isolated and comprise two distinct species. These findings have important implications for the conservation of bottlenose dolphins in Chinese waters.

Effects of L-glutamic acid on acid secretion and mucosal blood flow in the rat stomach

The effect of intravenous administration of L-glutamic acid (L-Glu) on gastric acid secretion and gastric mucosal blood flow (GMBF) in anesthetized rats were investigated. Infusion with synthetic L-Glu alone had no effect on spontaneous acid secretion. However, L-Glu reduced histamine- (2 mg/kg/hr) or oxotremorine- (1 microg/kg/hr) stimulated acid secretion, whereas L-Glu had no effect on acid secretion induced by pentagastrin (8 microg/kg/hr). Furthermore, this inhibitory effect of L-Glu on histamine- or oxotremorine-stimulated acid secretion was blocked by 6,7-dinitroquinoxaline-2,3-dione (DNQX), a non-NMDA receptor antagonist. The effect of L-Glu on gastric mucosal microcirculation in the anesthetized rats was evaluated by using Laser Doppler Flowmetry (LDF). The results showed that L-Glu did not significantly reduce both mucosal and serosal blood flow in stomach. No significant modulatory effect on histamine- or oxotremorine-stimulated increase in GMBF was noted after infusion with L-Glu. It is concluded that L-glutamic acid is capable of the modulating of gastric acid secretion via ionotropic non-NMDA receptors, but do not affect on GMBF. However, L-glutamic acid showed no effect on acid secretion by itself.

The effects of the rotating-hinge total knee replacement on gait and stair stepping

We studied 7 younger and 5 older patients who had rotating-hinge total knee replacements, 10 patients who had semiconstrained total knee replacements, and 8 younger and 11 older healthy control subjects to determine the effects of the rotating-hinge device on gait and stair stepping. The younger patients with the rotating-hinge device had few significant differences from the younger control subjects during gait or stair stepping. The older patients with the rotating-hinge device had several significant differences from both the older control subjects and subjects with the semiconstrained device during gait and stair stepping. Nevertheless, the proportions of older patients with the 2 devices who were able to perform the step-on activity for the highest step were the same.

Protein gene product 9.5-immunoreactive neurons in the retina of striped dolphin (Stenella coeruleoalba) and Fraser dolphin (Lagenodelphis hosei)

This study demonstrates immunocytochemically that protein gene product 9.5 (PGP 9.5), a neuronal marker, is expressed by various populations of retinal cells in Stenella coeruleoalba (striped dolphin) and Lagenodelphis hosei (Fraser dolphin): one in the retinal ganglion cells and the other in the inner nuclear layer, resembling horizontal and amacrine cells. The specific distribution of PGP 9.5 in a dolphin closely resembles that in rodents and carnivores; however, some differences arise among these animals. In a dolphin's retina, for example, only a few of giant ganglion cells are immunoreacted while almost all the small ganglion cells are stained strongly. The processes of horizontal cells, identified according to their localization, appear not to connect entirely in a dolphin. Instead, PGP 9.5 positive cells are widely distributed in the small to moderate ganglion cells and have distinct processes which are ramified extensively in the outer plexiform layer in rodents and carnivores. The high levels of PGP 9.5 expressing in the inner part of dolphin retina, including ganglion cells and their axons as well as distinct sublamination in the inner plexiform layer, indicate that this molecule markedly influences the retinal system, possibly in visual connection. Although mammals have various visual behavior, i.e., living marine vs. terrestrial environment, and active during daytime vs. in the night, the retina is a common model to characterize the neurochemical properties.

Cytopathologic effects of arecoline on human gingival fibroblasts in vitro

Arecoline, a major betel nut alkaloid, has been detected in saliva obtained during betel nut chewing in concentrations up to 140 micrograms/ml, corresponding to 0.9 mM. Arecoline in the millimolar concentration range might participate in the initiation and/or progression of periodontal disease during the long-term effects of betel nut chewing. In this study, cell growth, cell proliferation, assessment of cytoplasmic enzyme lactate dehydrogenase (LDH) and collagen synthesis were used to investigate the effects of human gingival fibroblasts exposed to arecoline levels of 0-200 micrograms/ml. Control culture exhibited a normal monolayer of long spindle-shaped fibroblast morphology. Arecoline-treated human gingival fibroblasts showed a more rounded appearance and detached at the higher concentrations. At concentrations higher than 75 micrograms/ml, many cells had detached from the surface of the petri dish and numerous floating cells could be seen under the inverted microscope. At a concentrations higher than 25 micrograms/ml, arecoline inhibited cell growth, proliferation and collagen synthesis and increased LDH leakage in a dose-dependent manner (P < 0.05). These results indicate that arecoline is a cytotoxic agent to human gingival fibroblasts. Repeated and long-term exposure to arecoline could impair gingival fibroblast function. Betel quid chewers might be more susceptible to destruction of the periodontium and less responsive to a regeneration procedures during periodontal therapy.

Influence of carbohydrate starvation and arginine on culturability and amino acid utilization of lactococcus lactis subsp. lactis

Two strains of Lactococcus lactis subsp. lactis were used to determine the influence of lactose and arginine on viability and amino acid use during carbohydrate starvation. Lactose provided energy for logarithmic-phase growth, and amino acids such as arginine provided energy after carbohydrate exhaustion. Survival time, cell numbers, and ATP concentrations increased with the addition of arginine to the basal medium. By the onset of lactose exhaustion, the concentrations of glycine-valine and glutamate had decreased by as much as 67% in L. lactis ML3, whereas the serine concentration increased by 97% during the same period. When no lactose was added, the concentrations of these amino acids remained constant. Similar trends were observed for L. lactis 11454. Without lactose or arginine, L. lactis ML3 was nonculturable on agar but was viable after 2 days, as measured by fluorescent viability stains and intracellular ATP levels. However, L. lactis 11454 without lactose or arginine remained culturable for at least 14 days. These data suggest that lactococci become viable but nonculturable in response to carbohydrate depletion. Additionally, these data indicate that amino acids other than arginine facilitate the survival of L. lactis during carbohydrate starvation.

Isolation and characterization of acid- and bile-tolerant isolates from strains of Lactobacillus acidophilus

Lactic acid bacteria have been reported to be useful as a health adjunct and are commonly added to food as the delivery mechanism. The literature contains many conflicting observations for their proposed benefits, and the mechanism of action is undefined. One source of variation is the large number of strains used without proper controls supplemented. Additionally, many of the organisms are not characterized for their acid shock response or the acid-tolerance response, which are known to vary among bacterial species. Our objective was to isolate acid-resistant and bile-resistant variants of Lactobacillus acidophilus and to determine the phenotypic changes. The acid- and bile-tolerant isolates were obtained using natural selection techniques after sequential exposure to hydrochloric acid (pH 3.5 to 7.0) and mixed bile salts. The acid- and bile-tolerant isolates retained their ability to grow at pH 3.5 with 0.3% bile after the selective pressure was removed and reapplied. Isolates varied from their parents for stability in freezing, lactose utilization, protease activity, aminopeptidase activity, plasmid profile, and cell-wall fatty acid profile. These data suggest that the isolated acid- and bile-tolerant isolates possess growth advantages over that of the parents under stress conditions and may be considered as candidates for probiotic strains after further characterization with animal models.

Increasing obstacle height and decreasing toe-obstacle distance affect the joint moments of the stance limb differently when stepping over an obstacle

Foot placement during gait is important in regulating the dynamics of the joints of the supporting limb and in maintaining balance of the whole body. We hypothesized that increasing obstacle height and decreasing toe-obstacle distance (distance between the trailing foot and the obstacle during stance of the trailing foot just prior to stepping over the obstacle) would affect the joint moments of the stance limb differently when stepping over an obstacle. A total of 14 healthy young adults stepped over an obstacle 51, 102, 153, and 204 mm in height in a self-selected manner (i.e. toe-obstacle distance was not controlled) and for toe-obstacle distance targets of 10, 20, 30, and 40% of their step lengths measured during unobstructed gait. The adduction and internal rotation moments at the ankle joint increased as toe-obstacle distance decreased. The adduction and internal rotation moments at the hip joint during early stance, the internal rotation moment at the knee joint during late stance, and the dorsiflexion moment at the ankle joint during late stance increased with obstacle height. Reductions in toe-obstacle distance had greater effects on the moments of the ankle joint, and increases in obstacle height had greater effects on the moments of the hip joint. These greater demands on joint moments may affect the abilities of those elderly having decreased muscle strengths to safely step over obstacles. Copyright 1998 Elsevier Science B.V.

In vitro evaluation of the cytotoxicity and genotoxicity of root canal medicines on human pulp fibroblasts

An intracanal medicine is often required because microorganisms in the dentinal tubes may be difficult to eliminate completely by instrumentation. Phenolic compounds are widely used in dental treatment as sedatives for the dental pulp or as disinfectants for caries and the root canal. In this study, propidium iodide fluorescence and DNA precipitation assay were used to investigated the cytotoxic and genotoxic effects of camphorated phenol and camphorated parachlorophenol on cultured human pulp fibroblasts in vitro. Both medicines reduced the content of double-stranded polynucleic acid of fibroblasts over a 24-h culture period in a concentration-dependent manner. Camphorated parachlorophenol was more cytotoxic than camphorated phenol. But, both medicines did not cause genotoxicity on pulp cells. The advantage of these experimental methods are simplicity and rapidity. Furthermore, this experimental system may be useful for preliminary cytotoxicity and genotoxicity screening of various dental medicines in vitro.

Placing the trailing foot closer to an obstacle reduces flexion of the hip, knee, and ankle to increase the risk of tripping

This study was performed to test the hypothesis that reducing the horizontal distance between the trailing foot (foot crossing the obstacle last) and obstacle, during stance just prior to stepping over the obstacle, would reduce flexion of the hip, knee, and ankle joints of the trailing limb when the toe is over the obstacle to reduce the vertical toe-obstacle clearance and increase the risk of tripping. Fourteen healthy young adults stepped over an obstacle of 51, 102, 153, and 204 mm height in a self-selected manner (i.e., toe-obstacle distance was not controlled) and for toe-obstacle distance targets of 10, 20, 30, and 40% of their step lengths measured during unobstructed gait. The reductions in toe-obstacle distance resulted in linear decreases in flexion of the hip, knee, and ankle when the toe was over the obstacle. Toe-obstacle clearance of the trailing limb decreased significantly as toe-obstacle distance decreased. The reductions in toe-obstacle distance led to contact of the trailing (but not the leading) foot with the obstacle, the closer the obstacle the greater the number of contacts. The reductions also resulted in linear decreases in swing time of the trailing limb from toe-off to when the toe was over the obstacle. The height of the hip was not affected by toe-obstacle distance. Angular velocity of knee flexion was found to increase linearly as toe-obstacle distance decreased and appears to be of primary importance in avoiding obstacle contact.

Cytotoxic effect of pingyangmycin on cultured KB cells

The antitumour antibiotic pingyangmycin (PYM; bleomycin A5) was isolated from many components of bleomycin (BLM) produced by Streptomyces pingyangensisn. PYM has a similar chemical structure to that of BLM but the terminal amine moiety is different. Therefore, it would be of significance to demonstrate the antitumour effect and action mechanism of PYM on cultivated tumour cells. In this study, we used the cell growth curve, plating efficiency, and DNA synthesis inhibition assay to demonstrate the cytotoxicity of PYM on cultured KB cells. In the meantime, the morphological variations of drug-treated cells were also observed. In addition, we used the DNA precipitation assay, a simple and rapid assay, for detecting DNA damage caused by PYM on cultured KB cells for potential genotoxicity. Our results indicate that the effect of PYM significantly inhibits the cell growth, colonyforming ability, and DNA synthesis of KB cells in a dose-dependent manner. Furthermore, when treated with 5 micrograms/ml of PYM for 24 h on cultured KB cells, DNA strand breaks can be induced (P < 0.05). Therefore, it is considered that the action mechanism of PYM is due to its ability to inhibit the synthesis of DNA and split the DNA chains.

Cytotoxic and non-genotoxic effects of arecoline on human buccal fibroblasts in vitro

Betel quid chewing has been linked to oral submucous fibrosis and oral cancer. Cytotoxicity and genotoxicity assays were used to investigate the pathobiological effects of arecoline on cultured human buccal fibroblasts. Arecoline increased double-stranded polynucleic acid at the concentration of 0.1 to 10 micrograms/ml in a concentration-dependent manner. At a concentration higher than 50 micrograms/ml, arecoline was cytotoxic to cultured fibroblasts and the cytotoxicity was dose-dependent. No genotoxicity for arecoline was found even at a concentration of 400 micrograms/ml. On the other hand, 600 micrograms/ml glutathione (GSH) and 200 micrograms/ml glycyrrhizin could prevent the arecoline-induced cytotoxicity. These results indicate that arecoline is a cytotoxic agent and no genotoxicity was found to human buccal fibroblasts. Furthermore, increasing consumption of GSH- and glycyrrhizin-rich foods may reduce the oral diseases associated with betel quid chewing.

Stepping over an obstacle increases the motions and moments of the joints of the trailing limb in young adults

Tripping over obstacles is the most frequently mentioned causes of falls. Thus, this study was performed to test the hypotheses that when crossing obstacles, toe-obstacle clearance and the three-dimensional motions and moments at the hip, knee, and ankle of the trailing limb (limb crossing the obstacle last) increase with obstacle height. Data were collected using an optoelectronic digitizing system and force platform. Fourteen healthy young adults were tested during unobstructed level walking and when stepping over obstacles of 51, 102, 153, or 204 mm heights. Toe-obstacle clearances of the trailing foot increased from 31 mm during unobstructed gait to an average of 146 mm when stepping over obstacles of any of these heights. Obstacle height was not found to affect toe-obstacle clearance. When the toe of the trailing limb was over the obstacle, the flexion angles of the hip and knee increased linerly with obstacle height. Compared to flexion of the hip or ankle, flexion of the knee appears to be of primary importance when crossing obstacles with the trailing limb. The maximum extension moment at the hip joint during late stance decreased linearly with obstacle height. At the knee joint, the maximum flexion moment during early stance and the maximum adduction moment during late stance increased linearly with obstacle height. At the ankle joint, the maximum dorsiflexion moment during late stance increased linearly with obstacle height. These greater demands on motions and moments may affect the abilities of those elderly having decreased muscle strengths to step over obstacles.

Minimum energy trajectories of the swing ankle when stepping over obstacles of different heights

This study was performed to test the hypothesis that the motion of the lower extremities when stepping over obstacles is governed by the criterion of minimum mechanical energy. The trajectories of the swing ankle during level walking and when stepping over obstacles of 51, 102, 153, and 204 mm heights were predicted and measured for eight healthy young adults. The predictions were made with a planar, seven-link linkage model based on the criterion of minimum mechanical energy using the method of dynamic programming. When stepping over obstacles, the predicted trajectories of the swing ankle were just high enough for the swing toe to clear the obstacles. The clearances measured between the obstacle and toe were significantly larger than those predicted. When stepping over obstacles the levels of work required to generate the measured trajectories were significantly larger (p < or = 0.002) than those required to produce the predicted trajectories. The amount of work necessary to generate the measured or predicted trajectories increased linearly (significant at p < or = 0.022) with obstacle height and, except when predicting the trajectory for the lowest obstacle, was significantly greater than that required when walking on level ground (p < 0.02). Thus, conservation of energy was found to become a less dominant criterion for governing the motion of the body when crossing obstacles than when walking on level ground.

Suppressive effects of methyl methacrylate on the mutagenicity and DNA adduct formation induced by 1-nitropyrene and benzo[a]pyrene

Methyl methacrylate (MMA) is widely used as a cement in dentistry, orthopaedic surgery and ophthalmology. Studies based on short-term genotoxicity tests have produced conflicting results in the last two decades. In the present study, the effects of MMA on the mutagenicity of 1-nitropyrene (1-NP) and benzo[a]pyrene (B[a]P) were evaluated with the Salmonella typhimurium TA98 strain in the absence and presence of S9 mix. The direct-acting mutagenicity of 1-NP was markedly decreased by MMA in a dose-dependent manner. However, a low inhibitory effect of MMA on the metabolic-acting mutagenicity of B[a]P was observed. MMA did not show mutagenicity within the concentrations of 4.7-37.6 microM either with or without S9 mix. The inhibitory effect of MMA was not due to its cytotoxicity because very low and/or no cytotoxicity of MMA to S. typhimurium TA98 was observed. To confirm the antimutagenicity of MMA against 1-NP and B[a]P, a 32P-postlabelling method was used to determine whether MMA modified DNA adduct formation produced by both compounds in calf thymus DNA. MMA inhibits the formation of 1-NP- and B[a]P-DNA adducts in a dose-dependent manner. The DNA adduct of 1-NP reduced by MMA was greater than that of B[a]P. Thus, we suggested that MMA was possibly acting as an inhibitor of chemical carcinogenesis.

Predicting the kinematics and kinetics of gait based on the optimum trajectory of the swing limb

An algorithm was developed to predict the minimum energy consumption trajectory of the swing limb. The method of dynamic programming, a multistage optimization method, was applied to generate the optimum trajectory of the swing ankle which minimized the mechanical energy required to generate the moments of the joints of the lower extremities during the single support phase of gait. Predictions and measurements of gait were compared for six healthy subjects. The predicted hip and knee flexion angles of the swing limb were not significantly different from those experimentally measured except for hip flexion at times greater than 75% of the swing period. The predicted ground reaction forces were not significantly different from the measured ground reaction forces. Furthermore, the moments about the joints were not significantly different from those computed using the measured ground reaction forces and kinematics of the limbs. The results of this study support the hypothesis that human gait is energy efficient.

Sequential cytogenetic alterations in hamster oral keratinocytes during DMBA-induced oral carcinogenesis

Using the hamster cheek pouch oral cancer model, we have performed a comprehensive analysis of the cytogenetic changes in hamster oral keratinocytes during 7,12-dimethylbenz[a]anthracene (DMBA)-induced carcinogenesis. Tumour induction in the hamster cheek pouch required repeated application of the carcinogen for 14 weeks. We have found that this hamster oral cancer model to be suitable for cytogenetic studies. Unlike human oral cancers where chromosome breaks have been shown, this is only infrequently observed in DMBA-treated hamster oral keratinocytes. Of importance is the finding that at the beginning of the second week of DMBA treatment, there is a significant increase of karyotypes demonstrating tetraploid or near-tetraploidy. We propose that the significant increase in hamster oral keratinocytes exhibiting tetraploidy be further evaluated as a marker of premalignancy/malignancy.

Choristomas of the oral cavity: a review

The choristoma is a tumorlike mass of normal cells in an abnormal location. Intraoral choristomas have been reported under a wide variety of names. This comprehensive review of the English-language literature on oral choristomas offers a classification of these lesions, analyzes their clinical and histologic features, and discusses possible pathogeneses and treatment.

The protection against and treatment of a liquid propane freeze injury: an experimental model

Liquid propane causes a severe, deep thermal injury in unprotected tissue. Delayed surgical intervention, as for thermal burns, has been the gold standard of treatment. An animal model of liquid-propane injury was devised to document injury, to demonstrate a better method of protection, and to define an appropriate management protocol. Twenty-eight rats were classified into four groups: unprotected tissue (n = 8), skin covered with wool (n = 8), skin covered with Neoprene (Wm. H. Horn & Brothers Inc., Philadelphia, Pa.) (n = 8), and skin covered with wool plus Neoprene (n = 4). Each group was subdivided into two exposure times: 6 seconds and 30 seconds. The mean temperatures +/- standard error of the mean of the various tissue levels initially and at 6 and 30 seconds of exposure were determined. Histologic examination demonstrated that full-thickness tissue necrosis occurred in unprotected and wool-covered tissue. Areas that were covered with Neoprene showed intact skin and subcutaneous tissue with underlying muscle necrosis. Examination of the tissue that was covered with wool plus Neoprene showed no histologic damage. There was no sign of tissue regeneration at the wound periphery, and there was no histologic difference in any group, whether the examination took place at 1 or 5 days after injury. This study demonstrated that the best form of protection appears to be a wool glove liner covered with a Neoprene glove. The histologic evidence suggests that a liquid-propane injury to unprotected tissue should be managed aggressively with early excision and grafting.

Ganglioneuroma of the mandible

This article reports a very rare case of ganglioneuroma within the mandible. The patient, 15 years of age at first diagnosis, has now had 17 years of followup and remains generally healthy, despite the continued presence of the tumor. Possible origin of the lesion, histologic differentiation of this tumor from normal ganglia, and recommendations for management are discussed. Two reported cases of ganglioneuroma that occurred centrally in the mandible are also reviewed.

Rare earth filters for intraoral radiography: exposure reduction as a function of kV(p) with comparisons of image quality

Radiographs of phantoms were produced using E-speed film and various rare earth X-ray beam filters. The rare earth filters considerably reduced the amount of radiation needed to produce diagnostic quality images and, in many cases, improved image quality. These filters can be implemented easily and inexpensively in a clinical setting, resulting in radiation exposure reductions of up to 71%.

Effect of developer temperature changes on the sensitometric properties of direct exposure and screen-film imaging systems

A heat exchanger was developed and incorporated into the recirculation system of a dental processor to maintain strict temperature control. Without the heat exchanger, developer temperature rose steadily over 8 h to a maximum of 35.7 degrees C: with the heat exchanger it was maintained, regardless of ambient conditions, at the desired temperature with virtually no fluctuation. Sensitometric properties of base and fog, speed, and average gradient were measured for D and E speed films and Lanex Regular/T-Mat G and Lanex Fast/T-Mat Hscreen-film systems at developer temperatures of 21.1, 23.8, 26.7, 29.4 and 32.2 degrees C. Small changes in these properties were found for D and E speed films: on the other hand, Lanex Regular/T-Mat G showed a 65% increase in base and fog and Lanex Fast/T-Mat H a 43% increase in average gradient over the temperature range studied. Although these changes may not be clinically significant for intra-oral and dental radiography, the variations in image quality may compromise controlled imaging experiments and clinically compromise radiographic quality when using screen-film systems.

Diazepam facilitates reflex bradycardia in conscious rats

The effects of diazepam on cardiovascular function were assessed in conscious rats. Intravenous administration of diazepam (1-30 mg kg-1) produced a dose-dependent decrease in both the mean arterial pressure and the heart rate. Also, reflex bradycardia was produced in rats by intravenous infusion of adrenaline (1.25-2.5 micrograms kg-1). Intravenous pretreatment of the rats with diazepam, although causing no change in the adrenaline-induced pressor effect, did enhance the adrenaline-induced reflex bradycardia. However, the diazepam enhancement of adrenaline-induced reflex bradycardia was antagonized by pretreatment of rats with an intravenous dose of picrotoxin (an agent blocks chloride channels by binding to sites associated with the benzodiazepine-GABA-chloride channel macromolecular complex). The data indicate that diazepam acts through the benzodiazepine-GABA-chloride channel macromolecular complex within the central nervous system to facilitate reflex bradycardia mediated through baroreceptor reflexes in response to an acute increase in arterial pressure.