Mechanical properties of native and decellularized reproductive tissues: insights for tissue engineering strategies.

Understanding the mechanical properties and porosity of reproductive tissues is vital for regenerative medicine and tissue engineering. This study investigated the changes in Young's modulus (YM), storage modulus (E'), loss modulus (E"), and porosity of native and decellularized bovine reproductive tissues during the estrous cycle. Testis tunica albuginea had significantly higher YM, E', and E" than the inner testis, indicating greater stiffness and viscoelasticity. Endometrium showed no distinct differences in YM, E', or E" across the estrous cycle or between horns. Ovaries exhibited significant variations in YM, E', E", and porosity, with higher YM and E' in the ipsilateral cortex and medulla during the luteal phase. Decellularized ovarian tissues displayed increased porosity. The oviduct displayed no significant differences in YM or E' in the isthmus, but the contralateral ampulla had reduced YM and E' in the luteal phase. These findings offer valuable insights into the dynamic mechanical properties and porosity of reproductive tissues, facilitating the development of biomimetic scaffolds for tissue engineering applications.

Ensemble GaAsSb/GaAs axial configured nanowire-based separate absorption, charge, and multiplication avalanche near-infrared photodetectors.

In this study, molecular beam epitaxially grown axially configured ensemble GaAsSb/GaAs separate absorption, charge, and multiplication (SACM) region-based nanowire avalanche photodetector device on non-patterned Si substrate is presented. Our device exhibits a low breakdown voltage (V BR) of ∼ -10 ± 2.5 V under dark, photocurrent gain (M) varying from 20 in linear mode to avalanche gain of 700 at V BR at a 1.064 µm wavelength. Positive temperature dependence of breakdown voltage ∼ 12.6 mV K-1 further affirms avalanche breakdown as the gain mechanism in our SACM NW APDs. Capacitance-voltage (C-V) and temperature-dependent noise characteristics also validated punch-through voltage ascertained from I-V measurements, and avalanche being the dominant gain mechanism in the APDs. The ensemble SACM NW APD device demonstrated a broad spectral room temperature response with a cut-off wavelength of ∼1.2 µm with a responsivity of ∼0.17-0.38 A W-1 at -3 V. This work offers a potential pathway toward realizing tunable nanowire-based avalanche photodetectors compatible with traditional Si technology.

Spontaneous Pneumothorax as Clinical Presentation in a Patient with COVID-19.

Spontaneous pneumothorax as an initial presentation is very rare in COVID-19 patient. We present a case where the initial presentation was that of a mild disease and on investigation was found to have pneumothorax without any predisposing risk factors.

Reactivation of Tert in the medial prefrontal cortex and hippocampus rescues aggression and depression of Tert(-/-) mice.

The role of telomerase reverse transcriptase (TERT) has been extensively investigated in the contexts of aging and cancer. Interestingly, Tert(-/-) mice exhibit additional but unexpected aggressive and depressive behaviors, implying the potential involvement of TERT function in mood control. Our conditional rescue experiments revealed that the depressive and aggressive behaviors of Tert(-/-) mice originate from Tert deficiency in two distinct brain structures. Reactivation of Tert in the hippocampus was sufficient to normalize the depressive but not the aggressive behaviors of Tert(-/-) mice. Conversely, re-expression of Tert in the medial prefrontal cortex (mPFC) reversed the aggressive but not the depressive behavior of Tert(-/-) mice. Mechanistically, decreased serotonergic signaling and increased nitric oxide (NO) transmission in the hippocampus transduced Tert deficiency into depression as evidenced by our observation that the infusion of a pharmacological agonist for serotonin receptor 1a (5-HTR1A) and a selective antagonist for neuronal NO synthase into the hippocampus successfully normalized the depressive behavior of Tert(-/-) mice. In addition, increased serotonergic transmission by the 5-HTR1A agonist in the mPFC was sufficient to rescue the aggressive behavior of Tert(-/-) mice. Thus, our studies revealed a novel function of TERT in the pathology of depression and aggression in a brain structure-specific manner, providing direct evidence for the contribution of TERT to emotional control.

Assessment of Short Term Cardiovascular Risk Among 40 Years and Above Population in a Selected Community of Kathmandu, Nepal.

BACKGROUND: Cardiovascular disease (CVD) risk assessment is effective for identifying whether people are at low or high risk of CVD events. It is also useful for determining the intensity of intervention. People with low risk of CVD can take more benefit by lifestyle modifications, whereas people at high risk need pharmacological intervention in addition. But, there is dearth of related study in Nepal. Therefore, this study aimed to assess short term CVD risk prediction in selected community of Kathmandu, Nepal. METHODS: We conducted a cross-sectional study in Sitapaila Village Development Committee, Kathmandu, Nepal between November 2014 and April 2015. We, first selected the household randomly to enroll 347 participants with 18 to 70 years of age, and later assessed the short term CVD risk prediction among ≥ 40 years age group using WHO/ISH chart. RESULTS: The mean age of respondents was 52 years. The majority of participants were female (58.4%), homemakers (45.2%), from Newar ethnic group (31.9%), and without formal education (42.8%). Smoking was present in 21.7% of respondents, diabetes in 19.9 %, and hypertension in 53.6%. The ≥10% CVD risk was seen in 14.6% (95% CI: 9.2, 20) of the respondents. It was significantly associated with age (p<0.001), education (p=0.027), smoking (p = 0.002), cholesterol level (p = 0.021), systolic hypertension (p <001), and diabetes (p = 0.019). CONCLUSIONS: The study population is in high risk of developing CVDs in near future. Lifestyle modifications and pharmaceutical interventions to manage the risk factors among study population are highly recommended.

Clinical Profile and Early Complications after Single and Dual Chamber Permanent Pacemaker Implantation at Manmohan Cardiothoracic Vascular and Transplant Centre, Kathmandu, Nepal.

BACKGROUND: Permanent pacemaker implantation is a minimally invasive surgical procedure in the management of patients with cardiac problems. However, complications during and after implantation are not uncommon. There is lack of evidences in rate of complications with the selection of pacemakers in Nepal. Therefore, this study was performed to compare the frequency of implantation and complication rate between single chamber and dual chamber pacemaker. METHODS: The present study is based on all consecutive pacemaker implantations in a single centre between April 2014 and May 2015. A total of 116 patients were categorized into two cohorts according to the type of pacemaker implanted- single chamber or dual chamber. All patients had regular 2-weeks follow-up intervals with standardized documentation of all relevant patient data till 6-week after implantation. Data were presented as means ± standard deviation (SD) for continuous variables and as proportions for categorical variables. Comparison of continuous variables between the groups was made with independent Student's t-test. For discrete variables distribution between groups were compared with Chi-square test. RESULTS: The mean age (±SD) of total population at implant was 64.08 (± 15.09) years. Dual chamber units were implanted in 44 (37.93%) of patients, single chamber in 72 (62.06%). Only 14 women (31.81%) received dual chamber compared with 42 women (58.33%) who received single chamber (Chi-square=18, DF=1, P = 0.0084). Complete atrioventricular block was the commonest (56.03%) indication for permanent pacemaker insertion followed by sick sinus syndrome (33.62%), symptomatic high-grade AV block (11.20%). Hypertension (dual chamber 21.55%, single chamber 40.51%) was the most common comorbidity in both cohorts. Complications occurred in 11 (9.48%) patients. More proportion of complication occurred in single chamber group (9 patients, 12.50%) than in dual chamber (2 patients, 4.54%). Complications occurring in dual chamber group include pocket hematoma 1 patient (2.27%) and arrhythmia in 1 patient (2.27%). Similarly, complications occurring in single chamber include RV perforation in two patients (2.77%) and one each (1.38%) had pocket hematoma, pneumothorax, infection, swelling at pocket site, arrhythmia in the form of NSVT, leads displacement, DVT and mortality. CONCLUSIONS: Women were more likely to receive single chamber systems than men. More proportion of complication occurred in single chamber group than in dual chamber. Future prospective studies on larger number of patients are needed to confirm and support our findings.

Smoking habit among male medical and dental students of B.P.Koirala Institute of Health Sciences, Nepal.

BACKGROUND: Smoking and health are intimately related and thus, smoking among future health care personnel is an important issue. As future physicians and dentists who will witness the continued burden of smoking-related diseases among their patients, represent a primary target for smoking prevention programs. OBJECTIVES: To explore the magnitude of smoking problem and assess the major causes aggravating the burden of smoking among medical and dental students. METHODS; A cross sectional study was conducted between June and July 2009 among 345 medical and dental students. Pre-tested self-administered questionnaire containing questions regarding smoking and its various correlates were used to collect the data. Chi square test was used for testing hypothesis. RESULTS: Prevalence of smoking was estimated as 38.4%, among whom majority started smoking during 15 to 19 years of life. Peer pressure was the major cause behind smoking (29.5%). Nearly one third of the participants used to consume alcohol along with smoking. Presence of parental smoking and use of other drugs were significantly associated with smoking among the students. CONCLUSION: Tobacco smoking is a significant health problem among the male medical and dental students. Medical and dental students were approached as they are the treatment providers for smoking and disease related to it in the future. The results in our study are discouraging and reveal that the medical knowledge regarding ill effects of smoking has not been able to check its use.

The burden of injury in terms of economics loss and disability days: a community based study form eastern Nepal.

BACKGROUND: Injuries are already a substantial public Health problem all over the world and are expected to increase in the 211st Century. They are major causes of deaths and disability in the population and also involve high societal costs. OBJECTIVES: This study was designed to assess the economic loss due to the injury and the disability days due to different types of injuries. METHODS: A systematic random sampling technique was used to select 1388 households from 19 wards. A detailed questionnaire was used to collect information related to injuries to the persons suffered from injuries including treatment obtained, cost of treatment (direct/indirect cost) and length of disability. RESULTS: Among the minor injured persons, majority (93.2%) did not spend any indirect cost. 36.7% of the major inured persons spent Nepalese rupees 10,001 to NRs 100,000 as direct treatment costs. But 50% spent less than 5000 NRs as indirect cost for major injury treatment. Maximum number (67.4%) of major injured persons had disability days of 31 to 90 days. CONCLUSION: The high incidence of injuries, especially road traffic injuries, adds a huge economic burden to nation.

An epidemiological study of injury among urban population.

BACKGROUND: Injuries are a focus of public health practice because they pose a serious health threat, occur frequently and are preventable. Injuries affect people of all ages and range from minor cuts and bruises to major catastrophes that take thousands of lives. OBJECTIVES: This paper aims to fi nd out the prevalence of injuries and to study the various epidemiological factors related to the injuries in Dharan. MATERIALS AND METHODS: A sample of 1398 households was taken as study sample. A systematic random sampling technique was used to select the 10% households from each 19 wards. A pre-tested questionnaire was used to collect demographic information and information related to injuries to the persons suffered from injuries. RESULT: The prevalence of minor injury in Dharan was 3.5% per month. The injury was common in the age group, 40-49 years (4.6%) and majority of injured persons were farmers (6.9%). Home was the common place (55.6%) for the minor injury. Cut/stab (32.8%) was the most common types of minor injury. The prevalence of major injury was 0.7% per year and occurred more among 50-59 years age group (1.7%). The commonest place for major injury was at road (53.1%) and service holders were at more risk (1.4%). Falls from the height (46.9%) were the most common types of major injury. CONCLUSION: The injuries related to lifestyle profession and road traffic accidents (RTA) is the commonest burden revealed in the study sample. Promotion of safety and education for protection at work and safe driving can prevent the major socio-economic loss to the family and community at large.

Fine needle aspiration (FNA) of soft tissue tumours (STT).

OBJECTIVES: The cytological findings of 50 ST Ts were evaluated aiming to determine the role of FNA in diagnosis of STTs METHODS: Fifty patients with soft tissue tumours underwent FNA in the preoperative investigation during a one year period. The smears were stained with Papanicolaou and May-Graunvald Giemsa stains. RESULTS: Forty-four cases were reported as benign, whereas 2 were malignant. Four cases revealed insufficient material. The malignant STTs were small round cell tumour and malignant spindle cell tumour. Cytological and histological correlation could be achieved in 40 cases. The overall sensitivity and specificity were 25% and 100% respectively with overall accuracy of 80%. CONCLUSION: A reliable diagnosis of STTs can be made with FNA when supported by other clinical and other diagnostic data.

Environmental noise induced hearing loss in Nepal.

INTRODUCTION: Noise pollution in urban cities is a serious problem and steadily increasing over the years. This has direct and indirect affect to the people that can lead to the health hazard. OBJECTIVES: To find out environmental noise induced health effect on people residing in an urban community and to predict the risk of the environmental noise induced hearing loss. MATERIAL AND METHODS: One hundred fifty questionnaires were filled up for the environmental noise pollution survey. For the case control study, 36 exposed and 25 non-exposed residents of Kupondole were included. Based on the place of residence (main road and 20 min. walking distance from the main road), subjects were divided into exposed and non-exposed group concerning environmental noise. Demographic data and information about health problems was obtained by a structured interview. Audiometric test was performed using manual audiometer. Odds ratios (OR) and their 95% confidence intervals (95% CI) for noise induced hearing loss were estimated using logistic regression. Adjustment for occupational noise was done. RESULTS: The major health effect induced by the environmental noise was observed as lack of concentration followed by irritation, fatigue and headache. The crude OR and 95% CI for the exposed subjects was 4.2 (1.4, 12). After adjustment for occupational noise, the OR (95% CI) was 4.0 (1.2, 13). CONCLUSION: This study shows that exposure to noise causes wide range of health effects. For the exposed subjects there was an increased risk of noise induced hearing loss. The risk was significantly increased also after adjusting for occupational noise.