Indications for Adjuvant Radiation after Radical Prostatectomy as Predicted by Artificial Intelligence-Derived Dominant Intraprostatic Lesion Volume

PURPOSE/OBJECTIVE(S)

In prostate cancer, PI-RADs scores of dominant intraprostatic lesions (DILs) in multi-parametric magnetic resonance imaging (mpMRI) are prognostic; however, their inter-observer agreement is only moderate. Artificial intelligence (AI) may be a powerful tool for prognostication by analyzing a large number of scans consistently in a short amount of time. This study investigated whether the DIL volume (DILvol) provided by an AI deep-learning segmentation algorithm could predict adverse findings at radical prostatectomy (RP), some of which could warrant adjuvant radiation therapy (RT).

MATERIALS/METHODS

We conducted a retrospective study of 185 consecutive patients with localized prostate cancer who underwent an endorectal coil, high B-value (> = 1000 s/mm2), 3-Tesla mpMRI followed by RP between 2015 and 2017. Using a previously trained deep learning nnUNet algorithm for providing DIL segmentations from patients treated with definitive RT, we segmented the DIL for the RP cohort. We evaluated the association of AI DILvol with the risks of adverse pathologic factors, including positive margins, pathologic T3 (pT3) disease, and pathologic Gleason (pGS8-10) disease, using separate univariate logistic regression models. We then included AI DILvol, pT3 (vs pT2), pGS8-10 (vs pGS6-7), margin status, and pre-RP PSA for predicting post-RP PSA values utilizing multivariate linear regression analysis. Finally, we included these same factors into a multivariate logistic regression analysis for predicting the risk of meeting adjuvant RT indications (PSA persistence post-RP > = 0.1 ng/mL or positive lymph nodes).

RESULTS

The median time between RP and post-PSA value was 1.6 months. The Pearson's correlation coefficient between AI and reference DILvol (sum of manually contoured PI-RADS 3-5 lesions) was 0.86 (p < 0.001). The Pearson's correlation coefficient between AI DILvol and pathologic tumor size was 0.63 (p < 0.001). Utilizing separate univariate logistic regression models, we found that AI DILvol was significantly associated with the risks of positive margins (OR 1.31 [1.10, 1.58]; p = 0.003), pT3 (OR 1.59 [95% CI: 1.30, 1.99]; p < 0.001), and pGS8-10 (OR 1.28 [1.07, 1.56]; p = 0.01). On multivariate linear regression, AI DILvol (0.27/mL [0.25, 0.29]; p < 0.001) was significantly correlated with post-RP PSA values, after controlling for adverse factors and pre-RP PSA. On multivariate logistic regression, AI DILvol (adjusted OR 1.32 [1.05, 1.69]; p = 0.03) was the only factor significantly associated with the risk of meeting adjuvant RT indications after controlling for these same factors.

CONCLUSION

For localized prostate cancer treated with RP, AI DILvol was the only factor significantly associated with the risk of meeting adjuvant RT indications, even after controlling for pathologic factors at RP. Further studies are needed to determine if AI DILvol is prognostic for long-term oncologic outcomes after RP.

Association between Artificial Intelligence-Derived Tumor Volume and Oncologic Outcomes for Localized Prostate Cancer Treated with Radiation Therapy

PURPOSE/OBJECTIVE(S)

Although clinical features of multi-parametric magnetic resonance imaging (mpMRI) have been associated with biochemical recurrence in localized prostate cancer, such features are subject to inter-observer variability. We evaluated whether the volume of the dominant intraprostatic lesion (DIL), as provided by a deep learning segmentation algorithm, could provide prognostic information for patients treated with definitive radiation therapy (RT).

MATERIALS/METHODS

We conducted a retrospective study of 438 patients with localized prostate cancer who underwent an endorectal coil, high B-value, 3-Tesla mpMRI and were treated with definitive RT at our institution between 2010 and 2017. We utilized the publicly available nnUNet to train a segmentation model which was used to identify the DIL. We examined the association between the artificial intelligence (AI)-generated DIL volume and oncologic outcomes, including biochemical recurrence and metastasis risk, using cause-specific Cox regression and time-dependent receiver operating characteristic analysis.

RESULTS

The AI model identified DILs with an area under the receiver operating characteristic (AUROC) of 0.827 at the patient level. For the 233 patients with available PI-RADS scores, with a median follow-up of 5.6 years, there were 28 biochemical failures. AI-defined DIL volume was significantly associated with biochemical failure (adjusted hazard ratio 1.60, 95% confidence interval 1.14-2.24, p = 0.007) after adjustment for PI-RADS score. Among all 438 patients with a median follow-up of 6.9 years, there were 49 biochemical failures and 22 metastases. The AUROC for predicting 7-year biochemical failure for AI volume (0.790) was similar to that for National Comprehensive Cancer Network (NCCN) category (p = 0.17). The AUROC for predicting 7-year metastasis for AI volume trended towards being higher compared to NCCN category (0.854 vs 0.769, p = 0.06).

CONCLUSION

An AI algorithm using deep learning could identify the DIL with good performance. AI-defined DIL volume may be able to provide prognostic information independent of the NCCN risk group or other radiologic factors for patients with localized prostate cancer treated with RT.

Provision of a personalized survivorship care plan and its impact on cancer-related health literacy among childhood cancer survivors in Hong Kong

PURPOSE

To evaluate the short-term effectiveness of a personalized survivorship care plan (SCP) in improving cancer-related literacy among childhood cancer survivors, and to identify characteristics of survivors who demonstrated minimal gain from the intervention.

METHODS

We recruited survivors diagnosed with cancer at ≤18 years old and were >2 years post treatment. The intervention included a personalized SCP and 30-minute health risk counseling. The participants' knowledge of their cancer diagnosis and potential treatment-related late effects (LEs) was assessed at baseline, immediately post intervention, and 1-3 months post intervention. Generalized estimating equation was used to test for changes in the awareness scores, with interacting terms (time*factor) added to identify differences in the score trajectory across clinically relevant subgroups.

RESULTS

In total, 248 survivors completed the intervention (mean age: 19.4 [SD = 6.7] years; 54.1% male; 66.1% hematological malignancies), of whom 162 completed all assessments. There was significant increase in survivors' awareness of their cancer diagnoses (mean adjusted score: baseline 66.9, post intervention 86.3; p < .001) and potential LEs (baseline 30.9, post intervention 66.3; p < .001). The proportion of survivors who demonstrated awareness of their potential LEs increased from 9.7% to 54.3%. The interaction analysis showed that there was significantly less improvement in awareness among survivors of non-central nervous system (non-CNS) solid tumors (p = .032), lower socioeconomic status (p = .014), and parents of pediatric survivors (vs. adult survivors; p = .013).

CONCLUSIONS

The provision of a personalized SCP showed preliminary effectiveness in improving survivors' understanding of their treatment-related LEs. Health counseling with SCP should be reinforced in vulnerable subgroups. Future work includes evaluating its long-term impact on lifestyle and health outcomes.

Healthcare workers acquired COVID-19 disease from patients? An investigation by phylogenomics

The increasing number of coronavirus disease 2019 (COVID-19) cases in the community has posed a significant epidemic pressure on healthcare settings. When healthcare workers (HCWs) acquire COVID-19, contact tracing and epidemiological investigation might not be adequate for determining the source of transmission. Here, we report a phylogenetic investigation involving two infected HCWs and nine patients to determine whether patient-to-HCW transmission had occurred in a hospital without a previous COVID-19 outbreak. This is the first study to apply phylogenomics to investigate suspected nosocomial transmission in a region with low prevalence of COVID-19. Our results do not support the occurrence of direct patient-to-HCW transmission.

Urine organic acid as the first clue towards aromatic L-amino acid decarboxylase (AADC) deficiency in a high prevalence area

BACKGROUND

Aromatic L-amino acid decarboxylase deficiency is a rare neurometabolic disease due to impaired decarboxylation of neurotransmitter precursors to its active form.

CASE

We retrospectively reviewed 8 cases from 2008 to 2019 with cerebrospinal fluid neurotransmitter analysis performed at our centre. All cases had an elevated urine vanillactic acid and, in most cases, with N-acetylvanilalanine detected. Cerebrospinal fluid analysis showed low downstream metabolites vanillylmandelic acid, homovanillic acid but high 3-O-methyl-L-DOPA, 5-hydroxytryptophan. Cerebrospinal fluid pterins were normal. Genotyping in DDC confirms the diagnosis. Urine organic acid analysis provided the first clue to diagnosis in four of the cases, which then triggered cerebrospinal fluid neurotransmitter and genetic analysis. We also developed a diagnostic decision support system to assist the interpretation of the mass spectrometry data from urine organic acids.

CONCLUSIONS

Urine organic acid could be essential in guiding subsequent investigations for the diagnosis of aromatic L-amino acid decarboxylase deficiency. We propose to screen suspected cases first with urine organic acids, specifically looking for vanillactic acid and N-acetylvanilalanine. Suggestive findings should be followed with target analysis for c.714 + 4A > T in ethnically Chinese patients. The assistive tool allowed expedite interpretation of profile data generated from urine organic acids analysis. It may also reduce interpreter's bias when peaks of interest are minor peaks in the spectrum.

67 Determine Risk of Fall in Medical Ward: An Exploratory Study

Introduction

Patient fall is very common in hospital. It is the biggest reason of hospitalization, morbidity and mortality. However there were few evidence on risk of fall. Thus, the aim of this study was to determine risk of fall and factor associated.

Method

A Cross-sectional study has been carried out from 3 January until 7 June 2019. A total number of 151 subject were recruited from selected medical ward. Data on Socio-demographic, medication, medical related history, vision and hearing impairment were collected. The outcome measures used were Hand Grip Strength, Timed Up and Go (TUG), and Berg Balance Score (BBS).

Result

There were significant difference between risk of fall with balance (p=0.00), right and left grip strengths (p=0.004&0.001), osteoarthritic Knee (p=0.006) and Functional reach (p=0.000).

Conclusion

The results show greater risk of fall associated with balance, grip strengths, osteoarthritic knee and Functional reach.

Solution structure analysis of the periplasmic region of bacterial flagellar motor stators by small angle X-ray scattering

The bacterial flagellar motor drives the rotation of helical flagellar filaments to propel bacteria through viscous media. It consists of a dynamic population of mechanosensitive stators that are embedded in the inner membrane and activate in response to external load. This entails assembly around the rotor, anchoring to the peptidoglycan layer to counteract torque from the rotor and opening of a cation channel to facilitate an influx of cations, which is converted into mechanical rotation. Stator complexes are comprised of four copies of an integral membrane A subunit and two copies of a B subunit. Each B subunit includes a C-terminal OmpA-like peptidoglycan-binding (PGB) domain. This is thought to be linked to a single N-terminal transmembrane helix by a long unstructured peptide, which allows the PGB domain to bind to the peptidoglycan layer during stator anchoring. The high-resolution crystal structures of flagellar motor PGB domains from Salmonella enterica (MotB_C2) and Vibrio alginolyticus (PomB_C5) have previously been elucidated. Here, we use small-angle X-ray scattering (SAXS). We show that unlike MotB_C2, the dimeric conformation of the PomB_C5 in solution differs to its crystal structure, and explore the functional relevance by characterising gain-of-function mutants as well as wild-type constructs of various lengths. These provide new insight into the conformational diversity of flagellar motor PGB domains and experimental verification of their overall topology.

Serodiagnosis of dengue virus infection using commercially available antibody and NS1 antigen ELISAs

Accuracy of the InBios DENV Detect IgM, IgG and NS1 antigen (Ag) ELISAs (Seattle, WA) for detection of dengue virus (DENV) infection were evaluated using 100 retrospectively selected sera from acutely febrile patients presenting to a Singapore hospital. The InBios DENV NS1, IgM and IgG ELISAs had an overall sensitivity of 83.6%, 40% and 58.2% and an overall specificity of 97.8%, 97.8% and 55.6%, respectively. Simultaneous testing for NS1 and IgM-antibodies yielded a sensitivity and specificity of 85.5% and 95.5%, respectively, which did not significantly differ from testing for NS1 Ag alone. Using sera positive for IgM- or IgG-class antibodies to six common arboviruses, the InBios IgM and IgG ELISAs showed an overall analytic specificity of 89.2% and 66.4%, respectively. This study suggests that recent DENV infection can reliably be detected by the InBios NS1 Ag ELISA alone and that InBios DENV IgG reactivity should be interpreted with caution.

Smoking among Secondary School Students in Negeri Sembilan, Malaysia

This study was done to determine the prevalence of smoking and factors influencing cigarette smoking among secondary school students in Negeri Sembilan, Malaysia. This is a cross-sectional school survey conducted on 4500 adolescent students based on a structured questionnaire. Data was collected using the supervised self administered questionnaire the Youth Risk Behaviour Surveillance in the Malaysian National Language Bahasa Malaysia. The prevalence of smoking among the students was 14.0%. About a third of the students (37.8%) started smoking at 13 to 14 years of age. The prevalence of smoking among the male students was higher (26.6%) compared to the female students (3.1 %). Adolescent smoking was associated with (1) sociodemographic factors (age, ethnicity, rural/urban status); (2) environmental factors (parental smoking, staying with parents); (3) behavioural factors (playing truant and risk-taking behaviours such as physical fighting, drug use, alcohol use, sexual activity, lack of seatbelt use, riding with a drunk driver); (4) lifestyle behaviours (being on diet and lack of exercise); (5) personal factors (feeling sad and suicidal behaviours). In conclusion, smoking is a major problem among Malaysian adolescents. Certain groups of adolescents tend to be at higher risk of smoking. This problem should be curbed early by targeting these groups of high risk adolescents. Asia Pac J Public Health 2005; 17(2): 130-136.

Potential benefits of diagnosis and treatment on health outcomes among elderly people with symptoms of overactive bladder

OBJECTIVES

This study examined potential benefits of diagnosing and treating elderly adults with overactive bladder (OAB) symptoms.

METHODS

Data were analysed from the OAB Re-Contact Study (N = 2750), a cross-sectional, self-reported Internet survey. Elderly respondents (65+ years old) with OAB were identified according to current medication use to control OAB symptoms or by scores > 14 (men) or > 16 (women) on the OAB Awareness Tool. Treated were those currently using prescription medication and never treated were those who never used prescription medication for OAB. Outcome measures included health-related quality of life, activity impairment, OAB-related severity and symptoms, and healthcare resource use (e.g. hospitalisations). Generalised linear models predicted health outcomes as a function of diagnosis or treatment, adjusting for covariates.

RESULTS

Diagnosed vs. not diagnosed elderly respondents had higher mental component summary (MCS) scores and SF-6D health utilities, and less activity impairment. Treated vs. never treated elderly respondents had higher MCS and SF-6D health utilities, less activity impairment, fewer OAB symptoms, lower OAB Awareness Tool scores, and lower odds of having bladder problems or incontinence. There were no significant differences in healthcare resource use. Further analysis by age group (middle-aged vs. elderly respondents) revealed significantly greater diagnosis- and treatment-related benefits on MCS (2.93 and 4.49 points more, respectively) and activity impairment (1.24 and 1.37 times as much, respectively) among elderly respondents.

CONCLUSIONS

Diagnosis and treatment were each associated with a lower health burden for elderly adults with OAB symptoms. These findings highlighted the importance of diagnosis and treatment in alleviating OAB symptoms and their impact on health outcomes.

Recent insights on the significance of transcriptomic and metabolomic analysis of male factor infertility

Infertility is a worldwide reproductive health problem which affects approximately 15% of couples, with male factor infertility dominating nearly 50% of the affected population. The nature of the phenomenon is underscored by a complex array of transcriptomic, proteomic and metabolic differences which interact in unknown ways. Many causes of male factor infertility are still defined as idiopathic, and most diagnosis tends to be more descriptive rather than specific. As such, the emergence of novel transcriptomic and metabolomic studies may hold the key to more accurately diagnose and treat male factor infertility. This paper provides the most recent evidence underlying the role of transcriptomic and metabolomic analysis in the management of male infertility. A summary of the current knowledge and new discovery of noninvasive, highly sensitive and specific biomarkers which allow the expansion of this area is outlined.

Preparation of activated carbon from sugarcane bagasse by microwave assisted activation for the remediation of semi-aerobic landfill leachate

This study evaluates the sugarcane bagasse derived activated carbon (SBAC) prepared by microwave heating for the adsorptive removal of ammonical nitrogen and orthophosphate from the semi-aerobic landfill leachate. The physical and chemical properties of SBAC were examined by pore structural analysis, scanning electron microscopy, Fourier transform infrared spectroscopy and elemental analysis. The effects of adsorbent dosage, contact time and solution pH on the adsorption performance were investigated in a batch mode study at 30°C. Equilibrium data were favorably described by the Langmuir isotherm model, with a maximum monolayer adsorption capacity for ammonical nitrogen and orthophosphate of 138.46 and 12.81 mg/g, respectively, while the adsorption kinetic was best fitted to the pseudo-second-order kinetic model. The results illustrated the potential of sugarcane bagasse derived activated carbon for the adsorptive treatment of semi-aerobic landfill leachate.

Preparation of tamarind fruit seed activated carbon by microwave heating for the adsorptive treatment of landfill leachate: A laboratory column evaluation

The preparation of tamarind fruit seed granular activated carbon (TSAC) by microwave induced chemical activation for the adsorptive treatment of semi-aerobic landfill leachate has been attempted. The chemical and physical properties of TSAC were examined. A series of column tests were performed to determine the breakthrough characteristics, by varying the operational parameters, hydraulic loading rate (5-20 mL/min) and adsorbent bed height (15-21 cm). Ammonical nitrogen and chemical oxygen demand (COD), which provide a prerequisite insight into the prediction of leachate quality was quantified. Results illustrated an encouraging performance for the adsorptive removal of ammonical nitrogen and COD, with the highest bed capacity of 84.69 and 55.09 mg/g respectively, at the hydraulic loading rate of 5 mL/min and adsorbent bed height of 21 cm. The dynamic adsorption behavior was satisfactory described by the Thomas and Yoon-Nelson models. The findings demonstrated the applicability of TSAC for the adsorptive treatment of landfill leachate.

Thrombolysis with reteplase, an unglycosylated plasminogen activator variant, in experimental embolic stroke

We incorporated diffusion-weighted magnetic resonance imaging (MRI) (DWI) and perfusion-weighted MRI (PWI) to evaluate the efficacy of thrombolysis in experimental embolic stroke using a plasminogen activator, reteplase. Reteplase (rPA) is an unglycosylated plasminogen activator with enhanced fibrinolytic potency. Right internal carotid arteries of 34 rabbits were embolized using aged heterologous thrombi. Baseline DWI and PWI scans 0.5 hours after embolization confirmed successful embolization among 32. Intravenous treatment with rPA (n=11; 1 mg/kg bolus), recombinant tissue plasminogen activator (rt-PA) (n=11; 6 mg/kg bolus over 1 hour), or placebo (n=10) commenced 1 hour after stroke induction. MRIs were performed at 1.75, 3, and 5 hours after embolization. Six hours after embolization, brains were harvested and examined for hemorrhage. Posttreatment areas of diffusion abnormality and perfusion delay were graded using both a semiquantitative scale and percent areas expressed as a ratio of the baseline values. Improved perfusion was seen among the rt-PA, and rPA-treated groups compared with placebo, using a semiquantitative scale (P<.01 rt-PA v controls, P<.05, rPA v controls). DWI scans, however, were not improved with thrombolysis. Cerebral hemorrhage was not increased with thrombolytic treatment, although the incidence of wound site hemorrhage was higher with either rPA or rt-PA. One fatal systemic hemorrhage was observed in each of the thrombolytic-treated groups. Cerebral perfusion was equally improved with either rt-PA or rPA without causing excess cerebral hemorrhage. An advantage of rPA is single-bolus dosing rather than continuous infusion. Use of rPA for stroke treatment should be further explored.

Human leukocyte class I antigen alleles A2 and A11 are not associated with nasopharyngeal carcinoma in West Malaysia

INTRODUCTION

Nasopharyngeal carcinoma (NPC) is the second most common cancer among Malaysian Chinese males. We determined the frequencies of 17 human leukocyte antigens (HLA), HLA-A and HLA-B, alleles in 88 Malaysian Chinese with NPC.

METHODS

Using polymerase chain reaction sequence-specific primers, the frequencies of 17 HLA-A and HLA-B alleles were analysed. They were A1, A2, A11, A31, A32, A33, B8, B13, B27, B38, B39, B44, B46, B55, B58, B61 and B71.

RESULTS

Three of the 17 alleles were detected in NPC patients. They were A1 (0.6 percent), A2 (56.3 percent) and A11 (43.2 percent). Three of the 17 alleles were detected in age- and sex-matched healthy individuals. They were A2 (50.0 percent), A11 (50.0 percent) and B27 (4.7 percent). The A2 and A11 alleles were evenly distributed in both groups, while A1 was only found in one NPC patient and B27 exclusively in healthy individuals.

CONCLUSION

We conclude that A1 is very rare, and A2, A11, A31, A32, A33, B8, B13, B38, B39, B44, B46, B55, B58, B61 and B71 alleles have no associations with the occurrence of NPC in Malaysia, while allele B27 is negatively associated.

Menstruation among adolescent girls in Malaysia: a cross-sectional school survey

INTRODUCTION

The onset of menstruation is part of the maturation process. However, variability in menstrual cycle characteristics and menstrual disorders are common. The purpose of this study was to determine the menstrual characteristics of adolescent females and factors associated with it.

METHODS

This is a cross-sectional descriptive study carried out on 2,411 secondary school adolescent females in Negeri Sembilan, Malaysia. Data were collected using a self-administered structured questionnaire on menstruation in Bahasa Malaysia.

RESULTS

Abnormal cycle length (menstrual cycle longer than 35 days or cycle length between 14 to 20 days or irregular pattern) was common and affected 37.2 percent of subjects. The majority (74.6 percent) experienced premenstrual syndrome and 69.4 percent had dysmenorrhoea. About 18 percent reported excessive menstrual loss (use two pads at a time to prevent blood from soaking through or confirmed by doctor to be anaemic due to heavy menstrual flow). Only 11.1 percent of schoolgirls seeked medical consultation for their menstrual disorders. Mothers remained the most important source of information (80 percent). Menstrual disorders were significantly more common in female adolescents who smoke and have suicidal behaviours (p-value is less than 0.05).

CONCLUSION

Menstrual problems among adolescent female are common. They are influenced by certain modifiable factors.

Premarital sexual intercourse among adolescents in Malaysia: a cross-sectional Malaysian school survey

INTRODUCTION

Sexual intercourse among Malaysian adolescents is a major concern, especially with the worry of HIV/AIDS. This study was done to determine the prevalence of sexual intercourse among secondary school students aged 12 to 19 years in Negeri Sembilan, Malaysia.

METHODS

This is a cross-sectional school survey conducted on 4,500 adolescent students based on a structured questionnaire. Data were collected using the self-administered questionnaire (translated version of the Youth Risk Behaviour Surveillance in Bahasa Malaysia).

RESULTS

The study showed that 5.4 percent of the total sample were reported to have had sexual intercourse. The proportion among male students who had had sex was higher (8.3 percent) compared with female students (2.9 percent). The mean age at first sexual intercourse was 15 years. One percent of students reported that they had been pregnant or had made someone else pregnant. Adolescent sexual intercourse was significantly associated with (1) socio-demographical factors (age, gender); (2) environmental factors (staying with parents); and (3) substance use (alcohol use, cigarette smoking, drug use), even after adjustment for demographical factors. The survey showed that 20.8 percent of respondents had taken alcohol, 14.0 percent had smoked cigarettes, 2.5 percent had tried marijuana, 1.2 percent had tried ecstasy pills, 2.6 percent had tried glue sniffing, 0.7 percent had tried heroin, and 0.7 percent had intravenous drugs.

CONCLUSION

Prevalence of sexual intercourse among Malaysian adolescents was relatively low compared to developed countries. However, certain groups of adolescents tend to be at higher risk of engaging in sexual intercourse. This problem should be addressed early by targeting these groups of high-risk adolescents.

Portfolio as a learning tool: students' perspective

Portfolio writing is a method of encouraging reflective learning among professionals. Although portfolio-based learning is popular among educators, not many studies have been done to determine students' perceptions of portfolio as a learning tool. A questionnaire survey was conducted among 143 medical students to find out their perceptions of the portfolio as a learning tool. A majority of the students felt that the portfolio is a good learning tool. However, they also perceived that it is stressful and time-consuming to develop a proper portfolio. The study indicates that students need appropriate guidance from the academic staff for the system to succeed.

Formation of LID vector complexes in water alters physicochemical properties and enhances pulmonary gene expression in vivo

There is currently an urgent need to develop efficient gene-delivery systems for the lung that are free of inflammatory effects. The LID vector is a synthetic gene delivery system, comprised of lipofectin (L), an integrin-targeting peptide (I) and DNA (D) that has previously been shown to have high transfection efficiency in the lung. We have assessed the effect of alternative methods of complex preparation on structural features of the complex, levels and duration of reporter gene expression and the host response to the LID vector. We have demonstrated that making the complex in water affects the structure of the LID complexes making them smaller and more stable with a more cationic surface charge than complexes prepared in phosphate-buffered saline (PBS). When the LID vector was constituted in water and instilled intratracheally into the lungs of mice there was a 10-fold increase in luciferase activity compared with preparation in PBS. Furthermore, luciferase activity was still evident 1 week following vector instillation. This enhancement may be because of altered complex structure, although effects of the hypotonic vector solution on the lung cannot be excluded. The inflammatory effects of instilling the LID vector in water were minimal, even after three administrations of the LID vector, with only mild alterations in cytokine and broncho-alveolar lavage fluid (BALF) cell profiles. These results demonstrate that the LID vector can generate high, and prolonged, levels of gene expression in the lung from small quantities of DNA and that careful attention to synthetic polyplex structure may be important to optimize efficiency of gene expression in vivo.

A study on the use of car occupant restraint in Selangor

A survey was conducted in December 1995 to study car occupant restraint usage in Selangor. A total of 1082 car occupants were observed in 536 cars. The results of the study shows that only 57.3% of the car occupants observed were protected by any form of restraints. Most of the cars (99.8%) examined had front seat belts but only 44.2% had rear seat belts. Only 0.6% of the cars were found to have child restraints in the cars. 80.2% of drivers used restraints and only 65.4% of front seat passengers used any forms of restraints. In the case of the rear seat passengers, only 0.42% used an available restraint. More people in the urban areas (84.42%) than in the rural areas (66.51%) used seat belts. Usage of seat belts by car drivers influenced the use of seat belts by front seat passengers. Type of seat belts fitted was associated with usage rate. It is sad to note that 21.9% of the drivers used seat belts incorrectly.

The rotary pursuit test is not an index of normal psychomotor function in humans

OBJECTIVE

This study sought to assess whether the rotary pursuit test is a good indication of the psychomotor performance of human subjects during normal working hours. Circadian hormonal profiles of salivary melatonin and cortisol were also established for correlation with performance.

METHODS

Ten healthy individuals working in the Department of Obstetrics and Gynecology laboratory participated in this study. The experiment was conducted during a normal 8.5-hour working day in which routine laboratory tasks such as running radioimmunoassays were performed. Saliva samples were collected every 2 hours starting at 8:00 a.m. Simultaneously, self-rated questionnaires on mood states, sleepiness, stress, and types of food and drinks consumed were also recorded. At 10:00 a.m., 12:00 noon, 2:00 p.m., and 4:00 p.m., the subjects' were tested on the rotary pursuit machine, on which their ability to track a rotating target with a stylus was tested by means of measuring the time the stylus stays on target.

RESULTS

The circadian profiles of salivary melatonin and cortisol were similar to what previous studies have shown. Increases in cortisol levels were associated with food intake, work stress, or spontaneous awakening. Tracking performance (time on target) improved significantly from 10:00 a.m. to 2:00 p.m. and then decreased nonsignificantly at 4:00 p.m. only at the speed setting of 60 rpm. There was no correlation between the three parameters measured.

SUMMARY

Variation of psychomotor performance during a normal working day and in noncircadian disrupted individuals cannot be measured by the rotary pursuit test. Furthermore, a learning effect could mask any variation in performance.

Effects of one night of sleep deprivation on hormone profiles and performance efficiency

This study examined the effects of one night of sleep deprivation on melatonin and cortisol profiles, as well as performance efficiency of military service members. Sleep intervention consisted of total lack of sleep (N = 7) or 8 hours of sleep (control group; N = 7) during the night. All parameters were measured at selected time intervals before (day 1), during (only in sleep-deprived individuals), and after (day 2) sleep intervention. Rotary pursuit scores and handgrip strength data were used as indices of psychomotor and physical performance, respectively. In sleep-deprived individuals, more salivary melatonin, but not cortisol, was secreted than in subjects who slept adequately. Significant increases in melatonin and cortisol were noted, especially at 1:30 p.m. on the day after nighttime sleep deprivation. In contrast, the tracking scores for rotary pursuit and grip strength among sleep-deprived and rested individuals were comparable. Across a normal working day (day 1), all parameters studied revealed time-specific fluctuations in both control and sleep-deprived groups. Irrespective of nighttime sleep schedule, the patterns of performance on day 2 differed from those on day 1. The tracking performance improved on day 2, whereas grip strength worsened, which may reflect inherent learning and muscle fatigue, respectively. During the night of sleep deprivation, performance declined. In conclusion, the present study showed that one night of sleep deprivation (8 hours) resulted in significant hormonal changes on the next afternoon but did not modify tracking and muscular strength performance.

Circadian disturbances after night-shift work onboard a naval ship

The aim of the present study was to investigate how night duties can affect the circadian rhythms of military personnel working onboard a naval ship. Twenty individuals on a regular day-work schedule from 9:00 a.m. to 6:00 p.m. (serving as controls) and 40 individuals on night-shift duties participated in the study. Salivary melatonin and cortisol profiles were established within two 24-hour periods from 2-hour saliva samplings. Under the condition of abrupt shift in work/rest schedule, the majority of the navy officers (52%) retained their normal melatonin profiles. Twelve percent displayed a right phase shift in melatonin rhythm after night work. Nineteen percent exhibited distortions in the form of abnormal peaks or troughs, and 17% showed signs of disrupted rhythm in the form of low daytime levels of melatonin throughout the sampling period. No consistent relationship was found between the melatonin changes and various work stations of the ship. Prominent changes in the cortisol profile included unexpected peaks or troughs that may be related to the conditions that individuals were exposed to, i.e., high noise level in the engine room, as well as to performing intense tracking operations. The findings of this study (1) show the possible detrimental effects of shift duties on circadian rhythms, (2) highlight a wide interindividual variation in the manner in which the circadian systems respond to an abrupt phase shift in work/rest schedules, and (3) form the basis for further investigations into effective strategies to help military personnel cope with shift work, thereby maintaining health and high working standards while on duty.

Sleep/wake cycle and circadian disturbances in shift work: strategies for their management--a review

INTRODUCTION

There has been a growing concern about the ability of individuals to maintain adequate levels of performance over long work shifts, particularly when those shifts span night-time hours. It has, therefore, become expeditious to understand and apply principles of circadian rhythms in order to establish simple, rational and appropriate strategies to help our shift workers maximise their performance and minimise their health problems under the various shift work regimes. This review sought to outline several principles of circadian rhythms and the sleep/wake cycle and some possible strategies to manage disturbances in the sleep and performance arising from shift works.

METHODS

Many studies in this field had been carried out. The present review concerns studies which elucidate the general circadian principles as well as those which may provide helpful information applicable for us in the work environment we are living in.

RESULTS

It has been found that shift workers invariably suffer from a constellation of symptoms, which can sometime severely compromise their ability to perform optimally during their shift work. There are many factors that influence the sleep/wake cycle and thus, the performance of shift work. These include 1) circadian factors, 2) type of shift work, 3) how a person adapt to circadian disruption, 4) ageing, 5) sleep factors and 6) social and domestic factors.

CONCLUSIONS

Several possible strategies could be adopted to improve sleep and performance. These include 1) appropriate scheduling of shift work, 2) proper consideration of the speed of shift rotation, 3) strategies for sleep and napping, 4) installing appropriate lighting at the workplace, 5) the use of sleeping pills/hypnotics such as melatonin and melatonin agonists.

An interstitial light assembly for photodynamic therapy in prostatic carcinoma

OBJECTIVE

To develop an interstitial laser light delivery system using multiple optical fibres for photodynamic therapy (PDT) in the treatment of prostate cancer.

PATIENTS AND METHODS

A laser beam was divided equally with a 1 x 4 fibre splitter to deliver PDT simultaneously through four 2-cm long, flexible cylindrical optical diffusers. Biplanar transrectal ultrasonography (TRUS) and a template were used to position the optical fibres percutaneously. In vivo measurements of light penetration depth (1/micro[eff] ) in prostate tissue were made in seven patients, using a sheathed isoprobe to measure light fluence rates at varying radial distances from the diffuser. The prostate was fixed with stabilization needles to minimize displacement during needle placement.

RESULTS

The mean (sd, range) micro(eff) in the prostates of the seven patients was 0.35 (0.07, 0.22-0.44) mm-1, which produced closely parallel slopes of light attenuation. However, there was up to a 10-fold variation in absolute light levels at the same diffuser-detector separation distances amongst the seven patients, probably caused by blood pooling around the diffuser light source. A similar problem around the isoprobe detector was overcome by sheathing the probe in clear plastic tubing. By stabilizing the prostate, the optical fibre positioning was precise to within 2 mm.

CONCLUSION

Although this light delivery and TRUS assembly were developed for clinical PDT in the prostate, the same instrumentation can be used reliably for in vivo light-penetration studies. Haemorrhage was unpredictable and highlighted one of the main problems which needs to be overcome.

Backbone dynamics of a short PU.1 ETS domain

The resonance assignments, secondary structure and backbone dynamics of the ETS domain of the transcription factor PU.1 have been determined for the free protein in solution by NMR spectroscopy. The secondary structure for the free ETS domain is similar to that observed in the crystal structure of the PU.1 protein complexed with DNA, except that helix alpha2 and recognition helix alpha3 are shorter for the free protein in solution. Backbone dynamics of the protein have been examined using amide hydrogen-deuterium exchange and (15)N laboratory-frame spin relaxation measurements. A significant probability of local unfolding of helix alpha2, which precedes the loop-helix-loop DNA recognition domain, is inferred from the very fast hydrogen-deuterium exchange for amide protons in this helix. The (15)N relaxation measurements indicate that the protein is partially oligomerized at a concentration of 2.5 mM, but monomeric at a concentration of 0.3 mM. The (15)N relaxation data for the low concentration sample were interpreted, using the model-free formalism, to provide insight into protein dynamics on picosecond-nanosecond and microsecond-millisecond time scales. High flexibility of the protein backbone is observed for the residues in the loop between alpha2 and alpha3. This loop is variable in length and in structure within the class of winged helix proteins and is partially responsible for binding to DNA. The dynamic properties observed for alpha2, alpha3 and the intervening loop may indicate a correlation between protein plasticity in particular structural elements and recognition of specific DNA sequences.

The roles of multileaf collimators and micro-multileaf collimators in conformal and conventional nasopharyngeal carcinoma radiotherapy treatments

The purpose of this work is to study the efficacy and limitations of using standard multileaf collimators (MLCs) and micro-multileaf collimators (mMLCs) in the treatment of nasopharyngeal carcinoma (NPC) by conventional and conformal radiotherapy techniques. The penumbra characteristics of MLC, mMLC, and customized block collimated beams are measured with respect to leaf edge angle, beam energy, treatment depth, and field size and compared with those generated by a commercial three-dimensional planning computer system. Upon verification of the planning system, it is used to evaluate the treatment plans generated with these beam shapers for conventional and conformal NPC treatments. The effective penumbra of a MLC beam is strongly influenced by its edge angle, leaf width, and treatment depth. The suitability of standard MLCs in conventional NPC treatments is determined mainly by the edge angle to be used. For conformal NPC treatments involving six or more fields, dose volume histograms comparable to those of customized beam blocks are obtained with a standard MLC. The mMLC does not have the same restrictions as those on standard MLC but is limited to phase II treatment by its small usable field size. Both standard MLCs and mMLCs can be used to replace customized divergent beam blocks in both conventional and conformal NPC treatments. However, a MLC, due to its larger effective penumbra, may be unsuitable for use in cases when the tumor volumes extend very close to the critical normal structures. A mMLC, on the other hand, is limited by its small maximum field size and can only be used for collimating the facial portals in the second phase treatment.

Interstitial photodynamic therapy in the canine prostate

OBJECTIVE

To determine the depth of tissue destruction and the minimum light dose required for necrosis in interstitial photodynamic therapy (PDT), as a prerequisite for the investigational therapy of patients.

MATERIALS AND METHODS

Seven adult beagle dogs were given 2 mg/kg of the photosensitizer Photofrin intravenously and two controls received none. After 24 h, 450 J/cm of 630 nm wavelength laser light was delivered interstitially to the prostate via a 2 cm long diffuser fibre. Seven single-fibre treatments were performed in five sensitized dogs and two single-fibre treatments in the controls. The two remaining sensitized dogs had two fibres placed 10 mm apart within the prostate to determine the coalescence of PDT lesions. The penetration depth of light was measured in all prostates, and after PDT the extent of necrosis was assessed histologically.

RESULTS

The mean (standard deviation, SD) radius of PDT destruction around each diffuser was 5.3 (1.4) mm and PDT lesions overlapped in prostates treated with two fibres placed 10 mm apart. There was no observable tissue damage in the controls. The mean (SD) minimum light dose required for PDT necrosis was 84 (64) J/cm2. Differences among animals in the light penetration depth were small, with a mean of 2.14 (0.2) mm, and did not correlate with the depth of necrosis (P = 0.07). Bleeding around the optical diffuser fibre impeded light penetration.

CONCLUSION

Interstitial PDT in the canine prostate using Photofrin produced modest volumes of tissue necrosis. The minimum light dose required to induce necrosis was variable because bleeding was unpredictable in relation to the optical fibre.

Rotational diffusion anisotropy of proteins from simultaneous analysis of 15N and 13C alpha nuclear spin relaxation

Current methods of determining the rotational diffusion tensors of proteins in solution by NMR spectroscopy exclusively utilize relaxation rate constants for backbone amide 15N spins. However, the distributions of orientations of N-H bond vectors are not isotropic in many proteins, and correlations between bond vector orientations reduce the accuracy and precision of rotational diffusion tensors extracted from 15N spin relaxation data. The inclusion of both 13C alpha and 15N spin relaxation rate constants increases the robustness of the diffusion tensor analysis because the orientations of the C alpha-H alpha bond vectors differ from the orientations of the N-H bond vectors. Theoretical and experimental results for calbindin D9k, granulocyte colony stimulating factor, and ubiquitin, three proteins with different distributions of N-H and C alpha-H alpha bond vectors, are used to illustrate the advantages of the simultaneous utilization of 13C alpha and 15N relaxation data.

Anterior knee pain in the military population

Anterior knee pain in our military population consititutes a diagnostic and therapeutic problem that is not always easily solved. In recent years, a better understanding of the biomechanics of the patello-femoral joint has contributed to the successful classification and treatment of many patients. However, the cause of pain remains elusive in a significant subset of patients who show no clinical or radiographic evidence of patellar malalignment and continue to have persistent pain despite adequate physiotherapy. In this article, the classification and approach to anterior knee pain are reviewed. Emphasis is placed on dividing patients into four subsets namely; normal tracking, patellar tilt, patellar subluxation and extra-articular causes of anterior knee pain. A more rational approach to the problem can then be employed and successful rehabilitation and/or surgery can be expected.

Matrix metalloproteinase 2 (gelatinase A) regulates glomerular mesangial cell proliferation and differentiation

A biologic role for the 72-kDa gelatinase A (matrix metalloproteinase 2; MMP-2), beyond simple extracellular matrix turnover, was evaluated in glomerular mesangial cells. To determine the significance of MMP-2 secretion for the acquisition of the inflammatory phenotype, we reduced the constitutive secretion of MMP-2 by cultured mesangial cells with antisense RNA expressed by an episomally replicating vector or with specific anti-MMP-2 ribozymes expressed by a retroviral transducing vector. The phenotype of the transfected, or retrovirally infected, cells was profoundly altered from the activated state and closely approximated that of quiescent cells in vivo. The prominent differences included a change in the synthesis and organization of the extracellular matrix, loss of activation markers, and a virtually total exit from the cell cycle. Reconstitution with exogenous active, but not latent MMP-2, induced a rapid return to the inflammatory phenotype in vitro. This effect was specific to MMP-2, because the closely related MMP-9 did not reproduce these changes. Furthermore, this pro-inflammatory effect of MMP-2 is dependent upon the active form of the enzyme, which can be produced by an autocatalytic activation process on the mesangial cell plasma membrane. It is concluded that MMP-2 acts directly upon mesangial cells to permit the development of an inflammatory phenotype. Specific inhibition of MMP-2 activity in vivo may represent an alternate means of ameliorating complex inflammatory processes by affecting the phenotype of the synthesizing cells, per se.

In situ comparison of 665 nm and 633 nm wavelength light penetration in the human prostate gland

The depth of treatment in photodynamic therapy (PDT) of tumors varies with the wavelength of light activating the photosensitizer. New generation photosensitizers that are excited at longer wavelengths have the potential for increasing treatment depths. Tin ethyl etiopurpurin (SnET2), a promising second-generation photosensitizer is maximally activated at 665 nm, which may be significantly more penetrating than 633 nm light currently used with porphyrins in PDT. The penetration of 665 nm and 633 nm wavelength red light in the prostate gland was compared in 11 patients undergoing prostatic biopsies for suspected prostatic cancer. Interstitial optical fibers determined the light attenuation within the prostate gland. Of the 11 patients, 7 had dual wavelength and 4 had single wavelength studies. The mean attenuation coefficients, mueff, for 665 nm and 633 nm wavelength light were 0.32 +/- 0.05 mm-1 and 0.39 +/- 0.05 mm-1, respectively, showing a statistically significant difference (P = 0.0003). This represented a 22% increase in the mean penetration depth and at 10 mm from the delivery fiber there was 1.8 times as much 665 nm light fluence than 633 nm. The mean mueff at 665 nm for benign and malignant prostate tissue were similar (P = 0.42), however, there was significant interpatient variation (mueff ranging from 0.24 to 0.42 mm-1) reflecting biological differences of therapeutic importance. The enhanced light fluence and penetration depth with 665 nm light should allow significantly larger volumes of prostatic tissue to be treated with SnET2-mediated PDT.

Endothelial cell injury initiates glomerular sclerosis in the rat remnant kidney

The development of progressive glomerulosclerosis in the renal ablation model has been ascribed to a number of humoral and hemodynamic events, including the peptide growth factor, transforming growth factor-beta 1 (TGF-beta 1). An important role has also been attributed to angiotensin II (AII), which, in addition to its hemodynamic effects, can stimulate transcription of TGF-beta 1. We postulated that increased glomerular production of AII, resulting from enhanced intrinsic angiotensinogen expression, stimulates local TGF-beta 1 synthesis, activating glomerular matrix protein synthesis, and leads to sclerosis. Using in situ reverse transcription, the glomerular cell sites of alpha-1 (IV) collagen, fibronectin, laminin B1, angiotensinogen, and TGF-beta 1 mRNA synthesis were determined at sequential periods following renal ablation. The early hypertrophic phase was associated with global, but transient, increases in the mRNA for alpha-1 (IV) collagen. No changes were noted for fibronectin, TGF-beta 1, and angiotensinogen mRNAs. At 24 d after ablation, at which time sclerosis is not evident, endothelial cells, particularly in the dilated capillaries at the vascular pole, expressed angiotensinogen and TGF-beta 1 mRNAs, as well as fibronectin and laminin B1 RNA transcripts. By 74 d after ablation angiotensinogen and TGF-beta 1 mRNAs were widely distributed among endothelial and mesangial cells, and were particularly prominent in regions of evolving sclerosis. These same regions were also notable for enhanced expression of matrix protein mRNAs, particularly fibronectin. All receptor blockade inhibited angiotensinogen, TGF-beta 1, fibronectin, and laminin B1 mRNA expression by the endothelium. We conclude that, as a result of hemodynamic changes, injured or activated endothelium synthesizes angiotensinogen, triggering a cascade of TGF-beta 1 and matrix protein gene expression with resultant development of the segmental glomerular sclerotic lesion.

Interferon-gamma and interleukin-10 messenger RNA are up-regulated after orthotopic liver transplantation in tolerant rats: evidence for cytokine-mediated immune dysregulation

BACKGROUND

Immune regulation requires antigen recognition, signaling, activation, secretion of cytokines, and effector function by lymphocytes. Although there is redundancy in the activation and function of the immune response, some cytokines simultaneously promote and suppress different pathways of immunity. In the experiments reported here we compare cytokine gene expression within liver allografts from tolerant rats with normal and isografted liver tissue. We also compare the secretion of interferon-gamma (IFN-gamma) in the supernatant from mixed lymphocyte cultures by using peripheral blood lymphocytes stimulated against donor antigen.

METHODS

Orthotopic liver transplantations were performed using the cuff technique without hepatic artery revascularization. Nonisotopic in situ hybridization (ISH) was used to detect and localize messenger RNA to specific cells within tissue. Antisense DNA probes were generated to interleukin-2 (IL-2), IL-4, IL-10, and IFN-gamma. One-way mixed lymphocyte cultures were set up against irradiated donor splenocytes, and the supernatant was collected to measure IFN-gamma by enzyme-linked immunosorbent assay.

RESULTS

Expression of IFN-gamma and IL-10 was up-regulated in tolerant animals versus normal or isografted liver (p = 0.0002 and 0.0001, IFN-gamma and IL-10, respectively). In situ hybridization localized the expression of messenger RNA predominantly to the cytoplasm of the hepatocytes. Levels of IFN-gamma were higher in the supernatant from proliferating peripheral lymphocytes against donor antigen from tolerant animals versus naive control animals.

CONCLUSIONS

Expression of IFN-gamma and IL-10 is up-regulated in hepatocytes from allograft tissue after orthotopic liver transplantation. We believe that the up-regulation of IL-10 cross-regulates the effector function of IFN-gamma and supports cytokine-mediated immune dysregulation, which may be a mechanism of tolerance after orthotopic liver transplantation in rats.

Insulin-like growth factor-I promotes successful fetal pancreas transplantation in the intramuscular site

BACKGROUND

Fetal pancreas (FP) has the capacity for exuberant proliferation and engrafts in the safe, accessible intramuscular site. These characteristics make FP transplantation an attractive approach to the treatment of diabetes mellitus. Insulin-like growth factor-I (IGF-I) is an important mediator of growth and maturation of many tissues and has been shown to induce fetal islet proliferation.

METHODS

IGF-I was locally administered at a rate of 69 micrograms/kg/day to 0, 2, 4, 8, or 16 FP isografts placed into the thigh muscle of streptozotocin-induced diabetic Lewis rats (blood glucose > 350 mg/dl).

RESULTS

Diabetes was reversed in eight of eight animals receiving 16 FP and treated with IGF-I. One of seven animals receiving 16 FP without IGF-I treatment became euglycemic (p = 0.003). Similar improved conversion rates were seen in groups of animals receiving either eight, four, or two FP and treated with IGF-I, compared to groups receiving eight, four, or two FP without IGF-I treatment. Euglycemic recipients had physiologic glucose tolerance. The interval to conversion increased inversely in proportion to the amount of FP tissue transplanted.

CONCLUSIONS

These results show that local delivery of IGF-I has potent trophic effects on FP transplanted to the intramuscular site.

The effects of 20 weeks basic military training program on body composition, VO2max and aerobic fitness of obese recruits

Forty of the most obese recruits going through a 20 weeks Basic Military Training (BMT) program were selected from a cohort of 197 obese recruits. Their TBW, BF, FFW, VO2max, time taken to achieve VT (VTTime) and maximal heart rate (HRmax) were measured before, in the middle, and at the end of the program. The means for each of these variables measured in the 3 occasions were analysed for significant differences with the repeated measures analysis of variance. Variables that achieved significant difference were further analysed for pairwise difference with the post-hoc Tukey test. The critical value was set at p < 0.05. Mean TBW and BF decreased from 108.33 +/- 13.1 kg to 90.82 +/- 12.3 kg (p < 0.001), and 34.3 +/- 1.2% to 23.9 +/- 2.3% (p 0.001) respectively. Mean FW decreased from 37.4 +/- 4.8 kg to 22.0 +/- 4.5 kg (p < 0.001). FFW decreased slightly from a mean of 71.5 +/- 8.6 kg to 69.2 +/- 8.8 kg, which was not significantly different (p > 0.05). Mean VO2max increased from 28.1 +/- 6.3 ml.kg-1.min-1 to 32.1 +/- 5.1 ml.kg-1.min-1 (p < 0.001), and mean VTTime on similar exercise protocol increased from 13.3 +/- 2.7 minutes to 15.8 +/- 3.8 minutes (p < 0.001). Mean HRmax decreased from 183.5 +/- 12.1 beats.min-1 to 177.3 +/- 10.1 beats.min-1 (p < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Asymmetric origins of the mature glomerular basement membrane

Renal plasma filtration is a critical physiologic function that depends upon the precise composition and arrangement of the constituent extracellular matrix proteins within the glomerular basement membrane (GBM). The GBM develops during renal embryogenesis by the fusion of discrete basement membranes produced independently by endothelial and visceral epithelial cells, and, possibly from matrix secreted by the mesangial cells. In the mature animal, however, the epithelial cell has generally been accepted as the sole source of all GBM constituent proteins. Although the final structures and distributions of the component proteins have been defined by histochemical techniques, the individual contributions of the three resident glomerular cell types to the maintenance and turnover of the mature GBM remain uncertain. We report the application of a new technique, in situ reverse transcription (ISRT), for the localization of RNA transcripts of nine major GBM protein components within the closely apposed cells of the glomerulus. Using this technique, we demonstrate that in normal adult rat glomeruli the RNA transcripts for heparan sulfate proteoglycan and the laminin-S chain are primarily expressed by visceral epithelial cells, while Type IV alpha-1 and alpha-2 collagen transcripts were restricted to the endothelial cells in a heterogeneous pattern. RNA transcripts for entactin and the laminin-A and -B2 chains were expressed by all three glomerular cell types, while laminin-B1 and fibronectin transcripts were limited to the mesangium. These findings demonstrate that GBM synthesis in the mature animal is not restricted to the epithelial cell and that all intrinsic glomerular cells contribute to the production of GBM protein components. The ISRT technique also provided the additional, and unexpected, finding that appreciable synthetic heterogeneity exists within individual glomerular cell types.

Simply marking dentures in the SAF. Singapore Armed Forces

Forensic dentistry is important to the armed forces and denture markers are useful adjuncts in forensic dental identification. The dental services in the Singapore Armed Forces (SAF) recognise this need and have been marking dentures since 1987. The "inclusion method" chosen for marking dentures in the SAF is described.

Opposite effects of prefrontal cortex and nucleus accumbens infusions of flupenthixol on stimulant-induced locomotion and brain stimulation reward

Ventral tegmental area (VTA) stimulation produced conditioned place preferences for stimulation-paired environments the magnitudes of which were dose-dependently reduced by systemic application of the dopamine antagonist, haloperidol (0.0, 0.15, 0.3 mg/kg). Bilateral microinjections of cis-flupenthixol (FLU) into the nucleus accumbens (0.0, 1.0, 5.0 or 10.0 micrograms) also resulted in reductions in the size of stimulation-induced place preferences as well as reductions in the magnitude of the hyperlocomotor response to 1.5 mg/kg (s.c.) D-amphetamine. Comparable microinjections of FLU into the medial prefrontal cortex (PFC) produced diametrically opposite effects: the size of VTA stimulation-induced place preferences was either unaffected (1.0 and 5.0 microgram groups) or slightly increased (10 micrograms group) and amphetamine-stimulated hyperlocomotion was dose-dependently potentiated. These behavioral findings suggest a dopamine-mediated modulatory role for the PFC over reward relevant elements within the nucleus accumbens.

A study of amblyopia in 18-19 year old males

During a vision screening of 6,556 National Service pre-enlistees aged 18-19 years at the Medical Classification Centre of Central Manpower Base, 48 subjects were found to have visual acuity of 6/12 or less in one or both eyes in the absence of ocular pathology. The prevalence of amblyopia in this population is 0.73%. Amblyopia was due to anisometropia in 24 cases (50%), strabismus in 9 cases (18.7%), high astigmatism (meridional) in 7 cases (14.5%) and other causes or a combination of factors in 8 cases (16.7%). Strabismic amblyopia is most commonly associated with esotropia. There is a positive association between the severity of amblyopia and the degree of strabismus in strabismic amblyopes. Meridional amblyopia tends to be less severe than most other types of amblyopia. The amblyopes were detected late (average 7-10 years of age) and orthoptic treatment of a small minority of them upon diagnosis was unsuccessful.