Effectiveness of online advanced C.A.R.E suicide prevention gatekeeper training program among healthcare lecturers and workers in national university of Malaysia: A pilot study

BACKGROUND

Suicide is a major cause of death among adolescents and young adults, especially students. This is particularly true for healthcare students with a higher risk and more access to lethal means. Thus, it is vital for healthcare educators who have regular contact with these healthcare students to be trained as gatekeepers in preventing suicide. Evidence of the effectiveness of such gatekeeper training, mainly using an online module, is lacking predominantly in Malaysia. This study aims to investigate the effectiveness of an online gatekeeper suicide prevention training program that is conducted for healthcare lecturers.

METHODS

A single-arm interventional pre-and post-pilot study was conducted on a sample of healthcare lecturers and workers who are involved in supervising healthcare students. A purposive sampling technique was used to recruit 50 healthcare educators in Malaysia. The program was conducted by trained facilitators and 31 participants completed a locally validated self-rated questionnaire to measure their self-efficacy and declarative knowledge in preventing suicide; immediately before and after the intervention.

RESULTS

Significant improvement was seen in the overall outcome following the intervention, mostly in the self-efficacy domain. No significant improvement was seen in the domain of declarative knowledge possibly due to ceiling effects; an already high baseline knowledge about suicide among healthcare workers. This is an exception in a single item that assesses a common misperception in assessing suicide risk where significant improvement was seen following the program.

CONCLUSION

The online Advanced C.A.R.E. Suicide Prevention Gatekeeper Training Program is promising in the short-term overall improvement in suicide prevention, primarily in self-efficacy.

Posttraumatic Growth, Positive Psychology, Perceived Spousal Support, and Psychological Complications in Head and Neck Cancer: Evaluating Their Association in a Longitudinal Study

Despite head and neck cancer (HNC) association with various negative impacts, collective evidence is accumulating regarding the positive impacts of positive psychology on cancer survivors. However, data on how positive psychology is related to the psychological complications of HNC across time are lacking. This longitudinal study examined the trends of positive psychology (e.g., posttraumatic growth [PTG], hope, and optimism), perceived spousal support, and psychological complications (e.g., depression, anxiety, and posttraumatic stress symptoms) and determined the association between them, psychological complications, and PTG across two timelines among a cohort of HNC patients. A total of 175 HNC respondents exhibited an increasing trend of positive psychology and perceived spousal support while reporting a decreasing trend of psychological complications between baseline and follow-up assessments. A greater degree of hope and perceived spousal support contributed to a higher degree of PTG across time. Conversely, a higher severity of anxiety symptoms was associated with a lower degree of PTG over time. Female gender had a moderating effect on the association between severity of anxiety symptoms and PTG, but did not moderate the association between hope, perceived spousal support and PTG. This study indicates the pivotal role of incorporating psychosocial interventions into the treatment regimen to enhance the degree of hope and perceived spousal support and reduce the severity of anxiety symptoms, which, in turn, will facilitate the development of PTG in HNC patients.

Association between childhood trauma, intimate partner violence, and perceived parental competence among women abusing amphetamine-type stimulant

INTRODUCTION

This cross-sectional study examines the correlation between childhood trauma, intimate partner violence (IPV), and parenting self-efficacy among women who reported using amphetamine-type stimulants (ATS) in an institutional drug rehabilitation center.

METHODS

A total of 106 participants were recruited by purposive sampling, of which 88 were mothers. Questionnaires were used to collect sociodemographic data and study variables.

RESULTS

Most of these women had experienced emotional abuse, sexual abuse, and physical neglect in their childhood. IPV assessments revealed that 70.5% (n = 74) and 30.5% (n = 32) had experienced physical and sexual violence, respectively. In terms of parenting competency, they scored 79.5% for self-efficacy and 54.4% for parenting satisfaction. Childhood emotional abuse significantly increases the odds of individuals experiencing sexual violence by 20.9%.

DISCUSSION

We found that childhood trauma and IPV did not have a significant relationship with parenting efficacy. Conversely, childhood emotional abuse and physical abuse were negatively correlated to parenting satisfaction. It is imperative that any form of childhood abuse be recognized and stopped early to reduce the harm it brings to women later in life.

Strategies for mitigating the effects of a pandemic on Indian medical tourism

India is a favorable destination for medical tourism because ofits quality healthcare services and affordable treatment costs. Itis a continuously growing industry across the globe. But wheneverany pandemic situation arises, it adversely affects the industry.Currently, COVID-19 has a severe negative impact onthe medical tourism sector. This paper discusses the effects of apandemic, critical issues, SWOT analysis, and components thatmitigate the adverse effects of pandemic diseases on medicaltourism in India. During this phase, it is crucial to encouragedomestic medical tourism for the sustainability of this sector. India’sheritage of ancient medicine promotion, along with modernmedicine can captivate the medical tourists. The destinationcountry requires meeting the expectations of tourists throughquality services. With India entering this unexpected downturnin this sector, destination country it must emphasize the slowand steady growth of medical tourism against the current andpotential future pandemics.

Posttraumatic Growth and Coping Strategies Among Patients With Head and Neck Cancer: Do Approach Coping and Avoidant Coping Predict Posttraumatic Growth Over Time?

Despite an enormous number of studies addressing the importance of posttraumatic growth (PTG) among cancer patients, the literature lacks data regarding how different coping strategies affect PTG among head and neck cancer (HNC) patients over time. This longitudinal study investigated the PTG trend and coping over 5-7months among a cohort of HNC patients within the first year after their diagnosis. It determined an association between coping strategies and PTG over time. The study's HNC respondents were administered a socio-demographic and clinical characteristics questionnaire during their baseline assessments. Additionally, the Malay versions of the "PTG Inventory-Short Form" (PTGI-SF) and the "Brief Coping Orientation to Problems Experienced Inventory" (Brief COPE) were administered during respondents' baseline assessments and follow-up assessments (5-7months after the baseline assessments). In total, 200 respondents reported an increasing PTG trend and approach coping (active coping, planning, positive reframing, acceptance, emotional support, and instrumental support) and a decreasing trend of avoidant coping (self-distraction and denial) over time. Two approach coping strategies (acceptance and planning) significantly increased PTG while denial was the only avoidant coping strategy that significantly lowered PTG, after controlling for socio-demographic and clinical characteristics, over time. Our study's findings identified the need to incorporate psychosocial interventions that enhance approach coping and reduce avoidant coping into HNC patients' treatment regimes.

Risk of Depression Among MMT Patients: Does Coping Strategies and Perceived Social Support Play a Role?

INTRODUCTION

Patients receiving methadone maintenance therapy (MMT) experience higher level of stress and are at greater risk of developing mental health problems such as depression which could potentially affect both quality of life and treatment outcomes. This cross-sectional study is aimed at understanding the relationship between psychosocial factors such as social support, coping, and depression among patients receiving MMT in a Malaysian Hospital.

METHODS

One hundred and ninety-six patients attending MMT program were recruited. The Patient Health Questionnaire-9 (PHQ-9) was used to screen for depression, Multidimensional Scale of Perceived Social Support (MSPSS) was used to assess participants' perceived social support, and the Brief COPE questionnaire was used to assess coping strategies. The diagnosis of depression was made using Mini-International Neuropsychiatric Interview (MINI).

RESULTS

About 13.8% of our sample were diagnosed with depression. From our analysis, it was found that having higher levels of perceived social support (OR = 0.462, 95% CI 0.238-0.899, P < .05), the use of active and emotion focused coping mechanism (OR = 0.231, 95% CI 0.095-0.565, P < .005), and support seeking and self-distraction coping mechanism (OR = 0.196, 95% CI 0.074-0.521, P < .001) was associated with lower likelihood of depression. On the contrary, the use of dysfunctional coping strategies such as denial, behavioral disengagement, and self-blame was associated with increased likelihood of depression (OR = 9.384, 95% CI 3.081-28.581, P < .001).

CONCLUSION

Active and emotion focused along with support and self-distraction coping strategies, and higher levels of perceived social support may serve as a buffer against depression in patients receiving MMT.

Macrophage immunomodulation through new polymers that recapitulate functional effects of itaconate as a power house of innate immunity

Itaconate (ITA) is an emerging powerhouse of innate immunity with therapeutic potential that is limited in its ability to be administered in a soluble form. We developed a library of polyester materials that incorporate ITA into polymer backbones resulting in materials with inherent immunoregulatory behavior. Harnessing hydrolytic degradation release from polyester backbones, ITA polymers resulted in the mechanism specific immunoregulatory properties on macrophage polarization in vitro. In a functional assay, the polymer-released ITA inhibited bacterial growth on acetate. Translation to an in vivo model of biomaterial associated inflammation, intraperitoneal injection of ITA polymers demonstrated a rapid resolution of inflammation in comparison to a control polymer silicone, demonstrating the value of sustained biomimetic presentation of ITA.

The relations of internet and smartphone addictions to depression, anxiety, stress, and suicidality among public university students in Klang Valley, Malaysia

PURPOSE

This cross-sectional study examined the cyber-psychological correlates of depression, anxiety, stress, and suicidality among public university students in Klang Valley, Malaysia.

DESIGN AND METHODS

Participants were randomly selected using multi-stage sampling methods from three public universities in the study location. Participants completed measures of internet and smartphone addictions, depression, anxiety, stress, and suicidality, along with sociodemographic items.

FINDINGS

At bivariate level, both internet and smartphone addictions were found to have significant positive correlations with depression, anxiety, stress, and suicidality. At multivariate level, only internet addiction emerged as a consistent significant predictor for depression, anxiety, stress, and suicidality.

PRACTICE IMPLICATIONS

The present findings have implications for mental health professionals to routinely screen for psychological disturbance in young adults who have potential risks for internet addiction.

Coping Strategies among First and Third Year Medical Students in a Malaysian Public University

Background: Medical students lead a stressful life and therefore the coping strategy is very important for them to alleviate the stress. The objective of this study was to explore the coping strategy among the first year and third year medical students and also to identify any significant difference between genders and study-years. Materials & methods: This cross-sectional study involved first and third year medical students of University Kebangsaan Malaysia of session 2013/2014. Coping strategy was explored using the ‘Coping Inventory for Stressful Situations’ (CISS) which consist of 48-items where 16 under task-oriented, 16 under emotional-oriented and 16 under avoidance-oriented coping. A five-point Likert’ scale ranging from ‘1=not at all’ to ‘5=very much’ was used to rate the items. Results: Task oriented coping was found the most common strategy among all students while emotion oriented was the least. First year students scored significantly higher than third year showing their best effort to adapt a new environment with insignificant difference between genders. Conclusions: Task-oriented coping strategy of the students is a good sign of problem solving skills. Though majority of the students adapt this method of coping, still there are other methods in practice. Medical school should focus for growing awareness about the positive coping methods in response to stress. This is necessary for the long term benefit of the students as well for better service to the nation. J MEDICINE JUL 2019; 20 (1) : 5-11 

Caregiver depression: The contributing role of depression in patients, stigma, social support and religiosity

BACKGROUND

Depression has been well studied as part of caregiver burden among patients with severe mental illnesses. Curiously, though, there has been little data in terms of caregiver burden with specific focus on depression among caregivers of patients with major depressive disorder (MDD).

AIM

This study aims to determine the rate of depression among caregivers of person with depression and its psychosocial correlates, which include stigma, perceived social support, religious commitment and the severity of the patient's symptoms.

METHODS

A cross-sectional study was conducted among 165 patients diagnosed with MDD using the Mini-International Neuropsychiatric Interview (M.I.N.I.) together with their caregivers. Apart from gathering social demographic data, patients were administered the 16-item Quick Inventory of Depressive Symptomatology-Self-Rated Version (QIDS-SR 16), whereas the caregivers were required to answer Patient Health Questionnaire-9 (PHQ-9), Multidimensional Scale of Perceived Social Support (MSPSS), Duke University Religion Index (DUREL) and Depression Stigma Scale (DSS). Those who scored ⩾5 on PHQ-9 were further assessed with interviewer-rated M.I.N.I. to diagnose the presence of depression.

RESULTS

A total of 47 (28.5%) caregivers were found to have depressive symptoms. Out of that total, 13 (7.9%) were diagnosed to have MDD using M.I.N.I. From univariate analysis, factors associated with depression in caregivers were the severity of symptoms in patients ( p < .001), personal stigma in caregivers ( p = .037), the patients' current depressive episode ( p = .026) and lower perceived social support from friends ( p = .048). From multivariate analysis, only the patients' severity of depressive symptoms ( p < .001) and personal stigma in caregivers ( p = .048) were significantly associated with the caregivers' depressive symptoms.

CONCLUSION

Our findings suggested that the severity of patient depression and personal stigma of the caregivers were significant factors correlated with caregiver depression. Therefore, beyond optimizing the treatment of depression in patients, the issue of stigma among caregivers also needs to be addressed as a potential target of intervention.

Combination restoration in full mouth rehabilitation

Successful restoration of the dentition requires plenty of contemporary and conventional treatment techniques and planning and attachment retained partial dentures are one such kind of treatment modality in prosthodontics. Satisfactory restoration in a patient with a partially edentulous situation can be challenging especially when unilateral or bilateral posterior segment of teeth is missing. One such treatment modality is attachment-retained cast partial dentures. The purpose of this article is to provide an overview of a case with maxillary complete denture and opposing cast partial denture with precision attachment.

Relationship between occlusal plane and ala-tragus line in dentate individuals: A Clinical pilot study

Many methods have been used to establish the occlusal plane in complete denture prosthodontics. However, no single method seems to be fully accepted. Anteriorly, esthetic considerations help define the occlusal plane, and posteriorly the tongue, retromolar pad, and Stenson's duct are considered. Some dentists bisect the space between the residual ridges. The technique of using the ala-tragus line (Camper's line) to establish the occlusal plane is well documented. However, definitions of the ala-tragus line cause confusion, because the exact points of reference do not agree. For example, the glossary of prosthodontic terms states that the ala-tragus line runs from the inferior border of the ala of the nose to the superior border of the tragus of the ear while Spratley’ describes it as running from the center of the ala to the center of the tragus. This article concerns us the exact relationship between the occlusal plane and ala-tragus line in dentate individuals.

Stress among First and Third Year Medical Students at University Kebangsaan Malaysia

Objective:

To identify the stress-prevalence and coping-strategies among University Kebangsaan Malaysia (UKM) medical students.

Methods:

This was an observational study conducted among 234 UKM first and third year medical students. Standardized questionnaire on stress and coping strategies was used. Stress data was related to subjective experiences on some positive and negative adjectives such as tense, relaxed etc. Positive adjectives were measured by sign “++” and “+” scoring “1” while stress-negative adjectives were measured by sign “?” and “–“ scoring “0”. Forty-eight coping items under task, emotion and avoidance strategies were measured using 5-point Likert-scale.

Results:

Overall stress-prevalence was 49%. Female and Malay respondents were more stressed. Significant differences of stress-level was observed between Malays and non Malays in first year (p=0.04) and in third year (p=0.01). Most common strategies used to cope stress was task-oriented while emotion oriented was least.

Conclusion:

Stress-prevalence and stress-level in UKM medical students was high. Most of the respondents coped stress using task-oriented strategies. Stressor and its effective management must be ensured. Educational institutions should act as a creative designer of learning environment to get relieve from educational stressor.

A Paradigm shift in the concept for making dental impressions

Digital dental impression is a revolutionary technological advancement that so surpasses the accuracy and efficiency of former techniques for obtaining replicas of prepared teeth for the purpose of fabricating restorations that its adoption by dentists is rapidly eclipsing the use of elastomeric impression materials. The ultimate goals of dentists dedicated to quality restorative dentistry are to make their treatment of patients as accurate, stressless, and efficient as possible. By elimination of the everyday problems described above, there is no question that the significant advantages of digital impressions will make intraoral digital scanning standard procedure in most dental offices within the next several years. Furthermore, digital impressions have proven to reduce remakes and returns, as well as increase overall efficiency. The patient also benefits by being provided a far more positive experience. Finally, through the use of digital impression making, it has been determined that laboratory products become more consistent and require less chair time at insertion.

Waist circumference and not body mass index as the outcome of a group weight intervention for patients with severe mental illness

OBJECTIVE

Most weight interventions among patients with severe mental illness (SMI) used body mass index (BMI) as outcome measure but excluded waist circumference (WC) although the latter is a stronger predictor of obesity complications. This study aimed to assess a weight-management program consisting of education, exercise and behavioural techniques for patients with SMI using weight parameters including WC as the outcome measures.

METHODS

A group intervention was carried out as part of psychiatric outpatient community service. It used structured modules on diet, exercise and related topics comprising of education and exercises sessions with a total of 12-week duration. The participants were outpatients with SMI recruited through referrals to the program by the treating doctor. The participants' body weight, BMI and WC were measured at the baseline, fortnightly and at the end of the program.

RESULTS

A total of 27 patients participated in the program which was carried out in 6 cycles. The pre- and post-intervention comparisons analysis of the weight parameters found a significant reduction in the WC (mean=3.878 cm+5.165, p=0.001) while no significant changes were recorded in body weight and BMI.

CONCLUSION

Small but significant loss in WC and possibly weight maintenance were achieved using this non-pharmacological intervention. Modest loss in WC may have an impact on reducing the risk of obesity-related health risks.

Effect of ascophyllan from brown algae Padina tetrastromatica on inflammation and oxidative stress in carrageenan-induced rats

Sulfated polysaccharide ascophyllan was isolated from the brown algae Padina tetrastromatica and purified by ion-exchange chromatography. Anti-inflammatory effect of ascophyllan fraction against carrageenan-induced paw edema in rats was studied. Paw edema in rats was induced by injecting 0.1 ml, 1 % carrageenan suspension in 0.9 % NaCl solution into the sub-plantar tissue of the right hind paw. Carrageenan caused a significant increase in the activity of inflammatory marker enzymes like lipoxygenases and cyclooxygenase in peripheral blood mononuclear cells and paw tissue and also increased the concentration of prostaglandin E2 (PGE2) and myeloperoxidase (MPO) in paw tissue. When compared to the reference drug diclofenac, ascophyllan fraction-3 (AF3) treatment significantly reduced the activities of anti-inflammatory enzymes, concentration of PGE2 and MPO. AF3 treatment decreased the mRNA level expression of TNF-α and IL-6. Concentration of thiobarbituric acid reactive substances was decreased. Activities of antioxidant enzymes and reduced glutathione level were increased on treatment with AF3. Histopathology of paw tissue showed decreased edema formation and cellular infiltration on supplementation with AF3. Thus the results demonstrated the potential beneficiary effect of ascophyllan fraction on carrageenan-treated rats.

Correlates of depression, anxiety and stress among Malaysian university students

INTRODUCTION

University students face not only challenges related with independent living, but also academic challenges. This predisposes them to depression, anxiety and stress, which are fairly common.

OBJECTIVE

The aim was to assess the prevalence of depression, anxiety and stress, and identify their correlates among university students.

METHODS

A cross-sectional study was conducted on 506 students between the ages of 18 and 24 years from four public universities in the Klang Valley, Malaysia. Through an anonymous, self administered questionnaire, they were assessed by the Depression Anxiety Stress Scale-21 (DASS-21). Data on socio-demographic, family characteristics and living arrangement were also obtained. Student's t-test and one-way ANOVA were used to explore association between these aspects.

RESULTS

Analysis showed among all students, 27.5% had moderate, and 9.7% had severe or extremely severe depression; 34% had moderate, and 29% had severe or extremely severe anxiety; and 18.6% had moderate and 5.1% had severe or extremely severe stress scores based on the DASS-21 inventory. Both depression and anxiety scores were significantly higher among older students (20 and above) and those born in rural areas. Whereas, higher stress scores were significantly higher among older students (20 and above), females, Malays and those whose family had either low or high incomes compared to those with middle incomes.

CONCLUSIONS

The prevalence of anxiety is much higher than either depression or stress, with some differences in their correlates except for age. These differences need to be further explored for development of better intervention programs and appropriate support services targeting this group.

Knowledge and attitude on sex among medical students of a Malaysian university: a comparison study

INTRODUCTION

The objective of this study was to determine the relationship between clinical/socio-demographic factors with knowledge and attitude on sex among medical students of the National University of Malaysia (UKM).

METHODS

A cross-sectional study assessing 452 students using a self-administered questionnaire of knowledge and attitude was performed and had a response rate of 80%.

RESULTS

The majority of respondents were Malays (56%), females (57.5%), lived in urban areas (66.4%), had a median family income of RM3000 and perceived themselves as moderately religious (60%). The overall score on knowledge about sex was 21.7 of 35 (a higher score indicates better knowledge about sex). It was noted that 73.2% of students felt that they did not receive adequate training in medical school to deal with patients' sexuality and sexual problems, while 51.5% felt uncomfortable talking to patients about these issues. Students in the clinical year were more knowledgeable than those in pre-clinical years (22.67 versus 20.71, P < 0.001). No significant differences were found in terms of their backgrounds, such as being from urban or rural areas (P = 0.349) and between genders (P = 0.286). Only 54.9% of students had a satisfactory level of knowledge on sex (>22 marks [median score]).

DISCUSSION

The students' attitude on sex was considered conservative as the majority of them disagreed on premarital sex, masturbation, abortion, homosexuality and oral sex. Gender and religiosity have a large influence on attitudes on controversial sexual issues, whereas clinical status plays a small role. Knowledge on sex among UKM medical students is inadequate and their attitudes on sex are considered conservative. Integration of sexual medicine and health modules in the medical curriculum is crucial for students to more effectively address patients' sexual problems and promote non-judgmental attitudes towards patients.

Is increased libido an atypical symptom of bipolar depression? An interesting case

INTRODUCTION

Decreased libido is recognized as one of the vegetative symptoms of depression. Increased libido has not been acknowledged as one of its symptoms, neither has it been reported, particularly in depressed bipolar patients.

AIM

We hereby report a case of atypical presentation of increased sexual function in a patient in depressed phase of bipolar II thereby querying the fact, whether increased libido is actually an unrecognized atypical symptom of bipolar depression.

METHODS

A 48-year-old male presented with mood swings whereby his sexual function was increased during his depressive phase. Antidepressant, mood stabilizer, and antipsychotic medication were administered. Electroconvulsive therapy (ECT) was offered for augmentation therapy.

MAIN OUTCOME MEASURES

When sexual dysfunction is not identified, there is a risk of misdiagnosis and mismanagement.

RESULTS

Patient did not attain full remission with medication. Compliance with medication was an issue, most probably due to the sexual side effects. The patient refused ECT.

CONCLUSION

This case highlights atypical presentation of high libido in a patient in the depressive phase of bipolar II disorder. The uncommon presentation of a common illness posed a diagnostic challenge and complicated the subsequent management. It was concluded that increased sexual function deserves further consideration as a symptom of bipolar depression.

Modeling and sensitivity analysis of electron capacitance for Geobacter in sedimentary environments

In situ stimulation of the metabolic activity of Geobacter species through acetate amendment has been shown to be a promising bioremediation strategy to reduce and immobilize hexavalent uranium [U(VI)] as insoluble U(IV). Although Geobacter species are reducing U(VI), they primarily grow via Fe(III) reduction. Unfortunately, the biogeochemistry and the physiology of simultaneous reduction of multiple metals are still poorly understood. A detailed model is therefore required to better understand the pathways leading to U(VI) and Fe(III) reduction by Geobacter species. Based on recent experimental evidence of temporary electron capacitors in Geobacter we propose a novel kinetic model that physically distinguishes planktonic cells into electron-loaded and -unloaded states. Incorporation of an electron load-unload cycle into the model provides insight into U(VI) reduction efficiency, and elucidates the relationship between U(VI)- and Fe(III)-reducing activity and further explains the correlation of high U(VI) removal with high fractions of planktonic cells in subsurface environments. Global sensitivity analysis was used to determine the level of importance of geochemical and microbial processes controlling Geobacter growth and U(VI) reduction, suggesting that the electron load-unload cycle and the resulting repartition of the microbes between aqueous and attached phases are critical for U(VI) reduction. As compared with conventional Monod modeling approaches without inclusion of the electron capacitance, the new model attempts to incorporate a novel cellular mechanism that has a significant impact on the outcome of in situ bioremediation.

Serotonin transporter polymorphism, memory and hippocampal volume in the elderly: association and interaction with cortisol

The s allele variant of the serotonin transporter gene (5-HTT) has recently been observed to moderate the relationship of stress to depression and anxiety. To date no study has considered interactive effects of 5-HTT genotype, stress and hypothalamic-pituitary-adrenal (HPA) function on cognition in healthy, older adults, which may reflect developmental, functional or neurodegenerative effects of the serotonin transporter polymorphism. We investigated whether 5-HTT genotype interacts with cumulative life stress and HPA-axis measures of waking and diurnal cortisol slope to impact cognition in 154 non-depressed, older adults. Structural images of hippocampal volume were acquired on a subsample of 56 participants. The 5-HTT s allele was associated with both significantly lower delayed recall and higher waking cortisol levels. Presence of the s allele interacted with higher waking cortisol to negatively impact memory. We also observed a significant interaction of higher waking cortisol and the s allele on lower hippocampal volume. Smaller hippocampi and higher cortisol were associated with lower delayed recall only in s allele carriers. No impact or interactions of cumulative life stress with 5-HTT or cortisol were observed. This is the first investigation to identify an association of the 5-HTT s allele with poorer memory function in older adults. The interactive effects of the s allele and waking cortisol levels on reduced hippocampal volume and lower memory suggest that the negative effect of the serotonin polymorphism on memory is mediated by the HPA axis. Further, given the significant association of the s allele with higher waking cortisol in our investigation, future studies may be needed to evaluate the impact of the serotonin transporter polymorphism on any neuropsychiatric or behavioral outcome which is influenced by HPA axis function in older adults.

Characterization of metabolism in the Fe(III)-reducing organism Geobacter sulfurreducens by constraint-based modeling

Geobacter sulfurreducens is a well-studied representative of the Geobacteraceae, which play a critical role in organic matter oxidation coupled to Fe(III) reduction, bioremediation of groundwater contaminated with organics or metals, and electricity production from waste organic matter. In order to investigate G. sulfurreducens central metabolism and electron transport, a metabolic model which integrated genome-based predictions with available genetic and physiological data was developed via the constraint-based modeling approach. Evaluation of the rates of proton production and consumption in the extracellular and cytoplasmic compartments revealed that energy conservation with extracellular electron acceptors, such as Fe(III), was limited relative to that associated with intracellular acceptors. This limitation was attributed to lack of cytoplasmic proton consumption during reduction of extracellular electron acceptors. Model-based analysis of the metabolic cost of producing an extracellular electron shuttle to promote electron transfer to insoluble Fe(III) oxides demonstrated why Geobacter species, which do not produce shuttles, have an energetic advantage over shuttle-producing Fe(III) reducers in subsurface environments. In silico analysis also revealed that the metabolic network of G. sulfurreducens could synthesize amino acids more efficiently than that of Escherichia coli due to the presence of a pyruvate-ferredoxin oxidoreductase, which catalyzes synthesis of pyruvate from acetate and carbon dioxide in a single step. In silico phenotypic analysis of deletion mutants demonstrated the capability of the model to explore the flexibility of G. sulfurreducens central metabolism and correctly predict mutant phenotypes. These results demonstrate that iterative modeling coupled with experimentation can accelerate the understanding of the physiology of poorly studied but environmentally relevant organisms and may help optimize their practical applications.

Properties of metabolic networks: structure versus function

Biological data from high-throughput technologies describing the network components (genes, proteins, metabolites) and their associated interactions have driven the reconstruction and study of structural (topological) properties of large-scale biological networks. In this article, we address the relation of the functional and structural properties by using extensively experimentally validated genome-scale metabolic network models to compute observable functional states of a microorganism and compare the "structure versus function" attributes of metabolic networks. It is observed that, functionally speaking, the essentiality of reactions in a node is not correlated with node connectivity as structural analyses of other biological networks have suggested. These findings are illustrated with the analysis of the genome-scale biochemical networks of three species with distinct modes of metabolism. These results also suggest fundamental differences among different biological networks arising out of their representation and functional constraints.

The effects of alternate optimal solutions in constraint-based genome-scale metabolic models

Genome-scale constraint-based models of several organisms have now been constructed and are being used for model driven research. A key issue that may arise in the use of such models is the existence of alternate optimal solutions wherein the same maximal objective (e.g., growth rate) can be achieved through different flux distributions. Herein, we investigate the effects that alternate optimal solutions may have on the predicted range of flux values calculated using currently practiced linear (LP) and quadratic programming (QP) methods. An efficient LP-based strategy is described to calculate the range of flux variability that can be present in order to achieve optimal as well as suboptimal objective states. Sample results are provided for growth predictions of E. coli using glucose, acetate, and lactate as carbon substrates. These results demonstrate the extent of flux variability to be highly dependent on environmental conditions and network composition. In addition we examined the impact of alternate optima for growth under gene knockout conditions as calculated using QP-based methods. It was observed that calculations using QP-based methods can show significant variation in growth rate if the flux variability among alternate optima is high. The underlying biological significance and general source of such flux variability is further investigated through the identification of redundancies in the network (equivalent reaction sets) that lead to alternate solutions. Collectively, these results illustrate the variability inherent in metabolic flux distributions and the possible implications of this heterogeneity for constraint-based modeling approaches. These methods also provide an efficient and robust method to calculate the range of flux distributions that can be derived from quantitative fermentation data.

Osmolar relationships in infantile dehydration

We studied serum osmolality in 167 consecutive infants admitted for gastroenteritis with 5% or more dehydration. Osmolality was determined by the freezing-point method in a 0.2-mL sample of serum immediately on admission. Forty-one patients (24.6%) had hypo-osmolar dehydration, with a mean osmolality of 257 mOsm/kg (range, 234 to 270 mOsm/kg). Eleven patients (6.5%) had hyperosmolar dehydration, with a mean osmolality of 329 mOsm/kg (range, 312 to 369 mOsm/kg). Simultaneous serum and CSF osmolalities were determined in 14 patients with hypo-osmolar and eight with hyperosmolar dehydration. In patients with hyperosmolar dehydration, serum osmolality correlated well with CSF osmolality, but a poor correlation was seen between serum and CSF sodium levels. Convulsions occurred in two patients in whom the CSF osmolality was greater than the serum osmolality by more than 10 mOsm/kg. Convulsions also occurred in two patients with hypo-osmolar dehydration in whom the CSF osmolality was lower than the serum osmolality by more than 13 mOsm/kg.

Occurrence of HLA types in H. influenzae type B disease

We have studied 50 Caucasoid children under 7 years of age with Haemophilus influenzae b disease. Half of the patients (Group A) had invasive disease shown by positive blood and/or spinal fluid culture. The other half (Group B) had noninvasive disease characterized by fever, nasopharyngitis, negative blood culture, and positive throat culture. Age, number of other siblings under 12 years old in the family, immune response, antibody production and genetic markers were compared in the two groups. Significant difference between the two groups was only seen in their genetic markers. HLA-B12 was present in 52% of Group A patients as opposed to 16% in Group B patients (P less than .01). HLA-Bw40 was present in 24% of group B patients and absent in all Group A patients (P less than .01). These findings would suggest that susceptibility and resistance towards developing invasive type b disease may be genetically determined.

Growth, health, and development after neonatal gut surgery: a long-term follow-up

Growth and development data on 19 children who survived gut surgery in the immediate newborn period are presented. The follow-up period ranges from seven months to seven years six months, with a mean of three years eight months. Neonates who undergo gut resection are at a higher risk for delay in height and weight gain compared to those who have gut surgery without resection. Six of the 12 children who had gut resection showed delay in height gain and seven showed delay in weight gain. Of the seven children who had gut surgery but no resection, only one showed delay in height and weight gain after the age of 1 year. An individual approach and careful serial follow-ups are recommended for all children undergoing gut resection in the newborn period. Of the eight children who had psychometric testing in the gut-resected group, only two are normal. Three of the four older children in this group show signs of perceptuomotor defects, suggesting the need for subtesting such children at about 6 years of age so that remedial help, if necessary, may be provided when formal schooling begins.