Young People's Attitudes, Perceptions and Experiences of Social Distancing and Self-Isolation During the Second Wave of the COVID-19 Pandemic

Objectives: Social distancing and self-isolation were key parts of the UK's strategy for reducing the spread of COVID-19. This study explored young people's attitudes, perceptions and experiences of social distancing and social isolation during the COVID-19 pandemic. Methods: Qualitative individual, family and paired-friendship interviews were conducted. All 26 participants lived or worked in East London and were aged between 20 and 39 years. Results: Qualitative analysis revealed three main themes: 1) trust and breaking of the social distancing and self-isolation rules-trust in their friends to be careful and say if they are unwell; 2) own rule making-making their own household rules which made them less guilty about breaking national rules as they were adhering to rules (albeit their own); and 3) lack of clarity around self isolation and the need for practical support-confusion around length of time needed to self isolate and what self-isolation really meant. Conclusion: Developing more effective and targeted communications and practical support mechanisms to encourage better adherence to social distancing and self-isolation rules among young people will be essential to prevent the spread of COVID-19.

Hepatic sclerosing haemangioma showing restricted diffusion: A case report with histopathologic correlation

Hepatic sclerosing haemangiomas are rare benign tumours that are often difficult to distinguish from malignant tumours because these tumours do not show the typical imaging features of cavernous haemangiomas. We report a case of a sclerosing haemangioma that showed restricted diffusion and was difficult to differentiate from a malignancy.

A 60-year-old female was referred to our hospital for evaluation of a hepatic mass that was incidentally diagnosed after a CT scan for right lower quadrant abdominal pain.

Contrast-enhanced dynamic CT showed hepatic capsular retraction, with a small peripheral enhancement of the mass. The lesion appeared homogeneously hypointense on T1-weighted images, heterogeneously hyperintense on T2-weighted images, hyperintense on diffusion-weighted images, and hypointense on apparent diffusion coefficient (ADC) map. The lesion was suspected to be a cholangiocellular carcinoma and was surgically resected, but a final diagnosis of hepatic sclerosing haemangioma was made.

Hepatic sclerosing/sclerosed haemangiomas are usually considered to show an increased ADC, which is useful for distinguishing them from malignant tumours. However, in this particular case, most of the lesion contained many obliterated or narrowed vascular channels, which might have acted as septa restricting the diffusion of water molecules in the intervening fibrous and/or hyalinized tissue. Hepatic sclerosing haemangiomas in the process of becoming completely fibrotic may show restricted diffusion, similar to malignant tumours.

Epidemiology of Respiration with Mandibular Movement in Advanced Cancer Patients: A Multicenter Prospective Cohort Study

Background: Respiration with mandibular movement (RMM) is one of the important clinical signs of impending death. However, there is very limited data on its natural course. Objective and Methods: This study was conducted in 23 inpatient palliative care units in Japan. It aimed to explore the natural course of RMM. Results: Among a total of 1526 cancer patients included, 1065 patients (69.8%) had RMM. A total of 14.8% patients experienced respiratory arrest within 30 minutes from RMM onset, 14.3% within 30-60 minutes, 34.4% within 1-4 hours, 17.5% within 4-12 hours, 8.9% within 12-24 hours, and 10.4%> 24 hours. Mean oxygen saturation and percentage of patients with SpO₂ ≥90% at RMM onset were found to be significantly higher in patients with longer durations from RMM onset to death (p < 0.001). Conclusion: RMM occurred in a majority (80%) of dying patients within 12 hours. A minority of the patients survived >24 hours.

Optimal Paracentesis Volume for Terminally Ill Cancer Patients With Ascites

CONTEXT

Patients with malignant ascites often suffer from distressing symptoms, especially in their end-of-life stage. Although paracentesis is the most common treatment modality to alleviate such symptoms, the optimal volume of paracentesis is not known.

OBJECTIVES

To explore the efficacy and safety of paracentesis by the drainage volume for terminally ill cancer patients with malignant ascites.

METHODS

This was part of a multicenter prospective observational study (EASED study). Consecutive adult patients with advanced cancer admitted to 23 participating palliative care units were eligible. We analyzed patients with malignant ascites who received paracentesis. We compared paracentesis-free survival (PFS) using Cox regression among three groups with different paracentesis volumes: minimum: ≤ 1500 mL, small: 1500-2500 mL, and moderate: > 2500 mL. Trends of the difference in the numerical rating scale of abdominal distension (0-10) and adverse events were compared among the 3 groups.

RESULTS

Of the 1926 patients enrolled, 673 developed ascites (symptomatic, n = 374 and asymptomatic, n = 299). Finally, we analyzed 87 patients with paracentesis. Median PFS was 7 days. Compared with a moderate volume, small-volume paracentesis was not a significant risk for shorter PFS (HR: 1.14, 95% CI: 0.69-1.93), while a minimum volume was a significant risk (HR: 2.34). The abdominal distension intensity significantly decreased after paracentesis (median: 7.5 to 4.0), while the difference did not significantly increase as the volume of paracentesis rose (P = 0.61). No severe adverse event was observed.

CONCLUSION

Even small-volume paracentesis could alleviate abdominal distension of terminally ill cancer patients with malignant ascites without shortening the paracentesis interval compared with moderate-volume paracentesis. Small-volume paracentesis was a well-balanced treatment for these patients.

Exploration of optimal paracentesis volume for terminally ill patients with malignant ascites

12089

Background: Malignant ascites (MA) often causes distressing symptoms especially for terminally ill cancer patients. Control of such symptoms is generally difficult when it becomes refractory to standard antitumor therapies. Paracentesis is the most common treatment modality which provides rapid and temporary symptom relief, while it requires frequently repeated treatment to maintain symptom control. The optimal procedure is often a balance between the potential for symptom improvement and the known risks of adverse events such as hypotension and renal impairment. However, there are limited data regarding the optimal amount of fluid to be removed. The aim of this study was to explore the efficacy (paracentesis interval and symptom relief) and safety (adverse events) of paracentesis by the drainage volume. Methods: This is part of a multicenter prospective observational study (EASED study). Consecutive adult patients with advanced cancer admitted to 23 participating palliative care units were eligible. We analyzed patients with MA who received paracentesis. We compared paracentesis-free survival (PFS) using Cox regression among 3 groups with different paracentesis volumes: minimum: < = 1500 mL, small: 1500-2500 mL, and moderate: > 2500 mL, with adjustment for potential confounders: age, sex, the Karnofsky Performance Status, and variables of which P-values were < 0.1 in univariate analysis. Trend of the difference in abdominal distention numerical rating scale (NRS) before and after paracentesis and adverse events were compared among 3 groups. Under missing at random assumption, missing values were imputed using multiple imputation. Results: A total of 1926 patients were enrolled and 673 patients developed MA at admission. Of these, 586 patients never received paracentesis during their PCU stay. Thus, the population for analysis consisted of 87 patients. Median PFS was 7 days. Compared with a moderate volume, small-volume paracentesis was not a significant risk for shorter PFS (HR: 1.14, 95%CI: 0.69-1.93), while a minimum volume was a significant risk for shorter PFS (HR: 2.34, 95%CI: 1.25-4.39). The spline-based hazard ratio curve indicated that a dose-response of the ascites drainage volume to PFS was not likely when more than 2,000 mL of ascites was removed. Abdominal distension NRS significantly decreased after paracentesis (median: 7.5 to 4.0, p < 0.0001), while the difference did not significantly increase as the volume of paracentesis rose (p = 0.61). No severe adverse event was observed. Conclusions: Even small-volume paracentesis could alleviate abdominal distension of terminally ill cancer patients with MA without shortening the paracentesis interval compared with moderate-volume paracentesis. Small-volume paracentesis was an effective and safe treatment for such patients. Our findings may help physicians estimate an optimal volume of paracentesis for each patient with MA.

Subacute thyroiditis in a patient with psoriatic arthritis switched from secukinumab to adalimumab: a case report and literature review

A 71-year-old Japanese female with psoriatic arthritis (PsA) was admitted for fever and neck pain. Her medication had been switched from secukinumab, an interleukin (IL)-17A inhibitor, to adalimumab, a tumour necrosis factor (TNF)-α inhibitor, due to secondary failure for PsA. She was diagnosed with subacute thyroiditis (SAT) on the basis of thyroid hormone levels and thyroid ultrasound findings. Her SAT symptoms improved with prednisolone administration (15 mg/day). Following the administration of ixekizumab, an IL-17A inhibitor, her PsA improved without SAT relapse. SAT mechanism associated with TNF inhibitors remains unknown, but cytokine imbalance may be involved.

Patterns of Raised Blood Pressure in Vietnam: Findings from the WHO STEPS Survey 2015

This study aims to describe the prevalence of raised blood pressure and the situation of management for raised blood pressure among the adult population in Vietnam. It also aims to examine the association between diversified socioeconomic and behavioral factors of raised blood pressure and awareness of raised blood pressure. Data were obtained from the STEPS survey conducted in Vietnam in 2015. Survey sample was nationally representative with a total of 3,856 people aged 18-69 years old. The study outcomes included raised blood pressure and awareness of and control of raised blood pressure. Multiple logistic regression was used to examine the association of socioeconomic and behavior risk factors with the outcome variables. The overall prevalence of raised blood pressure in Vietnam in 2015 was 18.9% (95% CI: 17.4%-20.6%). The prevalence of raised blood pressure was higher among men. Significantly correlated factors with raised blood pressure were age, sex, body mass index, and diabetes status. Levels of awareness of raised blood pressure were higher among the older age group and overweight people and lower among ethnic minority groups. Raised blood pressure in Vietnam is a serious problem due to its magnitude and the unacceptably high unawareness rate in the population. Public health actions dealing with the problems of raised blood pressure are urgent, while taking into account its relationship with sex and socioeconomic status. It is clear that the interventions should address all people in society, with a focus on disadvantaged groups which are the rural and ethnic minority peoples.

Bone marrow-derived mesenchymal stem cells promote colorectal cancer progression via CCR5

Mesenchymal stem cells (MSCs) are recruited from BM to the stroma of developing tumors, where they serve as critical components of the tumor microenvironment by secreting growth factors, cytokines, and chemokines. The role of MSCs in colorectal cancer (CRC) progression was controversial. In this study, we found that C-C chemokine receptor type 5 (CCR5) ligands (i.e., C-C motif chemokine ligand 3 (CCL3), CCL4, and CCL5) were highly produced from MSCs using a chemokine array screening with conditioned media from the cultured human MSCs. A relatively strong CCR5 expression could be detected within the cytoplasm of several CRC cell lines. Regarding the effect of MSC, we found that the xenografts in which CCR5-overexpressing HCT116 cells were inoculated into immunocompromised mice were highly promoted in vivo by a mixture with MSCs. Notably, the CCR5 inhibitor, maraviroc, significantly abolished the MSC-induced tumor growth in vivo. In human clinical specimens (n = 89), 20 cases (29%) were high for CCR5, whereas 69 cases (71%) were low. Statistical analyses indicated that CCR5 expression in primary CRC was associated with CRC patients’ prognosis. Especially, stage III/IV patients with CCR5-high CRCs exhibited a significantly poorer prognosis than those with CCR5-low CRCs. Furthermore, we investigated the effects of preoperative serum CCR5 ligands on patients’ prognosis (n = 114), and found that CRC patients with high serum levels of CCL3 and CCL4 exhibited a poorer prognosis compared to those with low levels of CCL3 and CCL4, while there was no association between CCL5 and prognosis. These results suggest that the inhibition of MSC–CRC interaction by a CCR5 inhibitor could provide the possibility of a novel therapeutic strategy for CRC, and that serum levels of CCL3 and CCL4 could be predictive biomarkers for the prognosis of CRC patients.

Women's Preference for a Male Acquaintance Enhances Social Reward Processing of Material Goods in the Anterior Cingulate Cortex

Men, like the male of many animal species, use gifts to build satisfactory relationships with a desired woman. From the woman’s perspective, all gifts are not always equally rewarding; the reward value of a gift depends on two factors: (1) the giver and (2) the type of the gift (the gift’s social meaning). In this study, we investigated how these two factors interactively determine the reward value of a gift. Specifically, we examined how the neural processing for understanding a gift’s social meaning is modulated by preferences for the giver. We performed a functional magnetic resonance imaging (fMRI) study in which a female participant was asked to judge a gift from a male she was acquainted with in real life. We examined the interactive effects between (1) the female participant’s attitude toward the male acquaintance (liked vs. uninteresting) and (2) the type of the gift (romantic [e.g., bouquet, earrings, and perfumes] vs. non-romantic [e.g., pencils, memo pad, and moneybox]). We found that preference for an acquaintance selectively modulated activity in the anterior cingulate cortex (ACC) in response to romantic gifts, compared to non-romantic gifts. In contrast, if the woman was indifferent toward an acquaintance, no activity modulation was observed in this area for the same gifts. In addition, the ACC showed functional connectivity with the supplementary motor area/dorsal ACC (SMA/dACC), an area within the dorsal mediofrontal cortex, suggesting that it integrates action monitoring and emotional and cognitive processing in decision-making. These results suggest that attitude toward an opposite sex member has a modulatory role in recognizing the social meaning of material goods—preference for the member is a powerful modulator of social reward processing.

Towards effective prevention and control of helminth neglected tropical diseases in the Western Pacific Region through multi-disease and multi-sectoral interventions

Neglected tropical diseases (NTDs) cause serious health, social and economic burdens in the countries of the World Health Organization Western Pacific Region. Among the NTDs, helminth infections are particularly prominent with regard to the number of infected individuals and health impact. Co-endemicity is common among impoverished and marginalized populations. To achieve effective and sustainable control of helminth NTDs, a deeper understanding of the social-ecological systems governing their endemicity and strategies beyond preventive chemotherapy are required to tackle the multiple causes of infection and re-infection. We discuss the feasibility of implementing multi-disease, multi-sectoral intervention packages for helminth NTDs in the Western Pacific Region. After reviewing the main determinants for helminth NTD endemicity and current control strategies, key control activities that involve or concern other programmes within and beyond the health sector are discussed. A considerable number of activities that have an impact on more than one helminth NTD are identified in a variety of sectors, suggesting an untapped potential for synergies. We also highlight the challenges of multi-sectoral collaboration, particularly of involving non-health sectors. We conclude that multi-sectoral collaboration for helminth NTD control is feasible if the target diseases and sectors are carefully selected. To do so, an incentive analysis covering key stakeholders in the sectors is crucial, and the disease-control strategies need to be well understood. The benefits of multi-disease, multi-sectoral approaches could go beyond immediate health impacts by contributing to sustainable development, raising educational attainment, increasing productivity and reducing health inequities.

The deaf utilize phonological representations in visually presented verbal memory tasks

The phonological abilities of congenitally deaf individuals are inferior to those of people who can hear. However, deaf individuals can acquire spoken languages by utilizing orthography and lip-reading. The present study used functional magnetic resonance imaging (fMRI) to show that deaf individuals utilize phonological representations via a mnemonic process. We compared the brain activation of deaf and hearing participants while they memorized serially visually presented Japanese kana letters (Kana), finger alphabets (Finger), and Arabic letters (Arabic). Hearing participants did not know which finger alphabets corresponded to which language sounds, whereas deaf participants did. All of the participants understood the correspondence between Kana and their language sounds. None of the participants knew the correspondence between Arabic and their language sounds, so this condition was used as a baseline. We found that the left superior temporal gyrus (STG) was activated by phonological representations in the deaf group when memorizing both Kana and Finger. Additionally, the brain areas associated with phonological representations for Finger in the deaf group were the same as the areas for Kana in the hearing group. Overall, despite the fact that they are superior in visual information processing, deaf individuals utilize phonological rather than visual representations in visually presented verbal memory.

Prevalence of Trypanosoma cruzi infection in blood donors in El Salvador between 2001 and 2011

INTRODUCTION

El Salvador is regarded as a highly endemic country for Chagas disease, as evidenced by the relatively high estimated positive serology rate for Trypanosoma cruzi among blood donors. This study aimed to identify the factors contributing to this high rate by analyzing changes in T. cruzi seroprevalence.

METHODOLOGY

Secondary data were collected from 31 blood banks operated by the Ministry of Health, the Red Cross, the Institute of Salvadoran Social Security, and the Military Hospital. The data were analyzed to determine the number of cases of T. cruzi seropositivity, and the average prevalence of seropositivity by province. Simple linear regression was performed to identify trends in T. cruzi seropositivity.

RESULTS

Analysis of the 885,187 blood samples collected between 2001 and 2011 revealed 21,693 cases of transfusion-related infections, with a significant reduction of T. cruzi seropositivity from 3.7% in 2001 to 1.7% in 2011, reflecting a 54% decrease over the course of a decade (R(2) = 89.6%, p > 0.001). T. cruzi seroprevalence decreased in San Salvador, Santa Ana, Sonsonate, and Cuscatlán. In contrast, seroprevalence remained high with no decrease in Ahuachapán and San Vicente, and consistently low in the remainder of the country.

CONCLUSIONS

Although the national prevalence of T. cruzi among blood donors has decreased, it remains high in the provinces of Ahuachapán and San Vicente. Strengthening vector control activities and developing an approach for the systematic follow-up of prospective blood donors with positive serology for T. cruzi are required, especially in areas with high seropositivity.

Acute Chagas disease in El Salvador 2000-2012 - need for surveillance and control

Several parasitological studies carried out in El Salvador between 2000-2012 showed a higher frequency of acute cases of Chagas disease than that in other Central American countries. There is an urgent need for improved Chagas disease surveillance and vector control programs in the provinces where acute Chagas disease occurs and throughout El Salvador as a whole.

Geographical characterization of the triatomine infestations in north–central Guatemala

In an entomological study in 2002, the degree of domestic and peridomestic infestation with triatomine bugs and the geographical distribution of such infestations were investigated in north-central Guatemala. The survey team searched for triatomines in houses constructed with mud walls or thatched roofs, in villages suspected of being infested. The level of infestation observed was lower than that seen in the same area and in eastern Guatemala, in a preliminary survey, 3 years earlier. Most of the infestations detected were of Triatoma dimidiata but even this species was found in <7% of the houses investigated. Infestations with Rhodnius prolixus or other potential vectors of Trypanosoma cruzi were much rarer. The generally low levels of infestation make the elimination of R. prolixus and the reduction of the domestic population of Tri. dimidiata feasible in the study area. The southern part of the study area had higher levels of domestic infestation and colonization than the north, and peridomestic infestation was highest in the south-west. Given such geographical variation in the pattern of infestation, it would seem wise to stratify the study region into areas of high, moderate and low-risk of human-triatomine contact, so that appropriate vector-control strategies can be targeted at the worst-affected areas. Regular entomological surveillance, ideally with community participation, is recommended. Analysis of the relationship between the geographical patterns of infestation and factors such as vegetation, altitude and vector migration would be useful.

Vector control intervention towards interruption of transmission of Chagas disease by Rhodnius prolixus, main vector in Guatemala

In Guatemala, the Ministry of Health (MoH) began a vector control project with Japanese cooperation in 2000 to reduce the risk of Chagas disease infection. Rhodnius prolixus is one of the principal vectors and is targeted for elimination. The control method consisted of extensive residual insecticide spraying campaigns, followed by community-based surveillance with selective respraying. Interventions in nine endemic departments identified 317 villages with R. prolixus of 4,417 villages surveyed. Two cycles of residual insecticide spraying covered over 98% of the houses in the identified villages. Fourteen villages reinfestated were all resprayed. Between 2000-2003 and 2008, the number of infested villages decreased from 317 to two and the house infestation rate reduced from 0.86% to 0.0036%. Seroprevalence rates in 2004-2005, when compared with an earlier study in 1998, showed a significant decline from 5.3% to 1.3% among schoolchildren in endemic areas. The total operational cost was US$ 921,815, where the cost ratio between preparatory, attack and surveillance phases was approximately 2:12:1. In 2008, Guatemala was certified for interruption of Chagas disease transmission by R. prolixus. What facilitated the process was existing knowledge in vector control and notable commitment by the MoH, as well as political, managerial and technical support by external stakeholders.

Perlecan regulates bidirectional Wnt signaling at the Drosophila neuromuscular junction

Perlecan/Trol at the neuromuscular junction suppresses presynaptic canonical Wg signaling but enhances the postsynaptic Frizzled nuclear import pathway.

Heparan sulfate proteoglycans (HSPGs) play pivotal roles in the regulation of Wnt signaling activity in several tissues. At the Drosophila melanogaster neuromuscular junction (NMJ), Wnt/Wingless (Wg) regulates the formation of both pre- and postsynaptic structures; however, the mechanism balancing such bidirectional signaling remains elusive. In this paper, we demonstrate that mutations in the gene of a secreted HSPG, perlecan/trol, resulted in diverse postsynaptic defects and overproduction of synaptic boutons at NMJ. The postsynaptic defects, such as reduction in subsynaptic reticulum (SSR), were rescued by the postsynaptic activation of the Frizzled nuclear import Wg pathway. In contrast, overproduction of synaptic boutons was suppressed by the presynaptic down-regulation of the canonical Wg pathway. We also show that Trol was localized in the SSR and promoted postsynaptic accumulation of extracellular Wg proteins. These results suggest that Trol bidirectionally regulates both pre- and postsynaptic activities of Wg by precisely distributing Wg at the NMJ.

Chagas disease: assessing the existence of a threshold for bug infestation rate

To examine the existence of a possible threshold for the domestic infestation rate of Triatoma dimidiata, below which transmission becomes unlikely, a census was conducted in 59 Chagas disease endemic communities of El Salvador and Honduras. Entomological and serological tests were conducted targeting 4,083 households and 6,324 children between 6 months and 15 years of age. The overall domestic infestation rate of Triatoma dimidiata and seroprevalence among children were 12.9% and 0.49%, respectively. Communities with a domestic infestation rate at 8% or less consistently showed a seroprevalence of 0%. In communities with a domestic infestation rate above 8%, there was a wide range in seroprevalence. A domestic infestation rate of 8% could serve as the possible threshold below which transmission would become unlikely. The implementation of an 8% threshold for determining needs for universal insecticide spraying would lead to a 21% reduction in spraying-related costs.

Triatomine infestation in Guatemala: spatial assessment after two rounds of vector control

In 2000, the Guatemalan Ministry of Health initiated a Chagas disease program to control Rhodnius prolixus and Triatoma dimidiata by periodic house spraying with pyrethroid insecticides to characterize infestation patterns and analyze the contribution of programmatic practices to these patterns. Spatial infestation patterns at three time points were identified using the Getis-Ord Gi*(d) test. Logistic regression was used to assess predictors of reinfestation after pyrethroid insecticide administration. Spatial analysis showed high and low clusters of infestation at three time points. After two rounds of spray, 178 communities persistently fell in high infestation clusters. A time lapse between rounds of vector control greater than 6 months was associated with 1.54 (95% confidence interval = 1.07-2.23) times increased odds of reinfestation after first spray, whereas a time lapse of greater than 1 year was associated with 2.66 (95% confidence interval = 1.85-3.83) times increased odds of reinfestation after first spray compared with localities where the time lapse was less than 180 days. The time lapse between rounds of vector control should remain under 1 year. Spatial analysis can guide targeted vector control efforts by enabling tracking of reinfestation hotspots and improved targeting of resources.

[A case of rupture of post-gastrectomy afferent loop obstruction due to invasion by pancreatic cancer]

A 77-year-old man with history of distal gastrectomy with Billroth II reconstruction for peptic ulcer disease performed 55 years ago was admitted to our hospital for diarrhea and abdominal pain. Abdominal computed tomography revealed a dilatation of the afferent loop and the duodenum, and a low density mass located in the body of the pancreas, which invaded the gastro-jejunal anastomosis site as well as the celiac axis and the superior mesenteric artery. Judging from these findings, we diagnosed this case as acute afferent loop obstruction due to an unresectable pancreatic cancer. Endoscopic decompression of the afferent loop was unsuccessful. After a while, the patient complained a severe abdominal pain, and an emergency surgery was performed under the diagnosis of rupture of the afferent loop. At laparotomy, a perforation of the jejunum located at a 15 cm anal side from Ligament of Treitz was found, and Braun's anastomosis was performed using the perforated site. The patient was treated with chemotherapy and survived for 15 months after the operation. Prompt decompression of afferent loop should be performed for preventing a rupture in case of acute obstruction of the afferent loop.

Control of Chagas disease

The Southern Cone Initiative (Iniciativa de Salud del Cono Sur, INCOSUR) to control domestic transmission of Trypanosoma cruzi is a substantial achievement based on the enthusiasm of the scientific community, effective strategies, leadership, and cost-effectiveness. INCOSUR triggered the launch of other regional initiatives in Central America and in the Andean and Amazon regions, which have all made progress. The Central American Initiative targeted the elimination of an imported triatomine bug (Rhodnius prolixus) and the control of a widespread native species (Triatoma dimidiata), and faced constraints such as a small scientific community, the difficulty in controlling a native species, and a vector control programme that had fragmented under a decentralized health system. International organizations such as the Japan International Cooperation Agency (JICA) have played an important role in bridging the gaps between fragmented organizational resources. Guatemala achieved virtual elimination of R. prolixus and ;reduction of Tri. Dimidiata and El Salvador and Honduras revitalized their national programmes. The programme also revealed new challenges. Tri. dimidiata control needs to cover a large geographic area efficiently with stratification, quality control, community mobilization, and information management. Stakeholders such as the National Chagas Program, the local health system and their communities, as well as local government must share responsibilities to continue comprehensive vector control.

The impact of vector control on Triatoma dimidiata in the Guatemalan department of Jutiapa

In 2000, a national control operation against the triatomine vectors of Trypanosoma cruzi, based on house spraying with residual pyrethroid insecticides, was initiated in Guatemala. The impact of the operation against Triatoma dimidiata in the most heavily infested department, Jutiapa, was evaluated by pre- and post-spraying surveys of the vector populations. Of the houses checked for Tri. dimidiata in the baseline surveys, 18.3% were found to be infested with the bug, and in 12.1% of the villages investigated more than half of the houses were found to be infested. The later survey was conducted after 24,250 houses and their associated peridomestic structures (in the 336 villages in which >5% of the houses had been found infested in the pre-spraying survey) had been sprayed. As a result of just this one round of spraying, the mean percentage of houses found infested in each of the villages surveyed twice fell from 36.0% to 8.9%. After the spraying, the percentage of houses infested in each sprayed village was never >50%, and the houses in 35.2% of the sprayed villages that were re-surveyed appeared to have been completely cleared of triatomine bugs. Re-infestation and colonization were mainly observed inside the houses, probably indicating that some indoor bugs survived the spraying round. If the department of Jutiapa is to be freed and kept free from domestic infestation, the efficacy of the insecticide spraying needs to be improved, spraying techniques need to be reviewed, and insecticides need to be re-applied at regular intervals. An effective vector-surveillance system (preferably one in which community participation is encouraged) is also essential.

Na+/Mg2+ transporter acts as a Mg2+ buffering mechanism in PC12 cells

Mg(2+) buffering mechanisms in PC12 cells were demonstrated with particular focus on the role of the Na(+)/Mg(2+) transporter by using a newly developed Mg(2+) indicator, KMG-20, and also a Na(+) indicator, Sodium Green. Carbonyl cyanide p-(trifluoromethoxy) phenylhydrazone (FCCP), a protonophore, induced a transient increase in the intracellular Mg(2+) concentration ([Mg(2+)](i)). The rate of decrease of [Mg(2+)](i) was slower in a Na(+)-free extracellular medium, suggesting the coupling of Na(+) influx and Mg(2+) efflux. Na(+) influxes were different for normal and imipramine- (a putative inhibitor of the Na(+)/Mg(2+) transporter) containing solutions. FCCP induced a rapid increase in [Na(+)](i) in the normal solution, while the increase was gradual in the imipramine-containing solution. The rate of decrease of [Mg(2+)](i) in the imipramine-containing solution was also slower than that in the normal solution. From these results, we show that the main buffering mechanism for excess Mg(2+) depends on the Na(+)/Mg(2+) transporter in PC12 cells.

Impact of residual spraying on Rhodnius prolixus and Triatoma dimidiata in the department of Zacapa in Guatemala

As a vector control program to control Chagas disease in Guatemala, residual spraying of Rhodnius prolixus and Triatoma dimidiata was performed, and its impact was measured in the department of Zacapa. In order to identify infested villages and determine the degree of infestation, a baseline entomological survey to identify municipalities infested with vectors followed by an additional vector survey in areas known to be infested was conducted. Residual spraying using pyrethroid insecticides was performed at all the villages identified as being infested with the vectors. The residual spraying was shown to be highly effective against both vectors by the decrease in infestation indices after spraying. Analysis of the cost-effectiveness of the spraying showed that the average cost of insecticides per house is high when compared with that in Southern Cone countries.

Design and synthesis of Mg2+-selective fluoroionophores based on a coumarin derivative and application for Mg2+ measurement in a living cell

Novel Mg2+ fluorescent molecular probes (KMG-20-AM and KMG-27-AM; where AM is an acetoxymethyl group) based on a coumarin possessing a charged beta-diketone structure were designed and synthesized. These fluorescent probes produced a red shift from 425 to 445 nm in the absorption spectra after formation of a complex with Mg2+. The fluorescence spectra of these probes also showed a red shift from 485 to 495 nm and an increasing fluorescence intensity after formation of a complex with Mg2+. The optimum experimental conditions were excitation wavelength of 445 nm and a monitored wavelength of 500 nm, where these probes functioned as an indicator showing an image of increasing fluorescence in the presence of Mg2+. These probes showed a "seesaw-type" fluorescent spectral change with the isosbestic point at 480 nm due to the light excitation at 445 nm, which indicates that ratiometry can be used for the measurement. The molecular probes formed a 1:1 complex with Mg2+ and the dissociation constant (Kd) was 10.0 mM for KMG-20. The association constants of the probes with Mg2- were approximately 3 times higher than that with Ca2+, which showed that the selectivity of Mg2+ versus Ca2+ for these probes was over 200 times higher than that for commercially available Mg2+ fluorescent molecular probes such as mag-fura-2, Magnesium Green. As an application of these probes, intracellular fluorescent imaging of Mg2+ was demonstrated using a fluorescent microscope. After the addition of KMG-20-AM and KMG-27-AM into PC12 cells, a strong fluorescence was observed in the cytoplasm and a weak fluorescence in the nuclei region. After treatment with a high-K+ medium, the fluorescence intensity increased due to increasing intracellular Mg2+. The real image of Mg2+ release from the magnesium store was successfully observed with these Mg2+ fluorescent probes.

Relationship between toxicity and cadmium accumulation in rats given low amounts of cadmium chloride or cadmium-polluted rice for 22 months

To clarify toxic effects of long-term oral administration of low dose cadmium (Cd) on the liver and kidney, six groups of female Sprague-Dawley rats were fed a diet containing Cd-polluted rice or CdCl2 at concentrations up to 40 ppm, and killed after 12, 18, and 22 months. With toxicological parameters, including histopathology, there was no evidence of Cd-related hepato-renal toxicity, despite a slight decrease of mean corpuscular volume and mean corpuscular hemoglobin of red blood cells with 40 ppm CdCl2. Dose-dependent accumulation of Cd was observed in the liver and kidneys with peak levels of 130 +/- 42 micrograms/g and 120 +/- 20 micrograms/g, respectively, at 18 months in animals treated with 40 ppm CdCl2. A dose-dependent increase in urinary Cd levels became evident with time. Induction of metallothionein (MT) was also observed in the liver and kidney with a high correlation to the corresponding Cd levels. In the proximal renal tubular epithelia of 40 ppm CdCl2-treated rats at 22 months, prominent accumulation of Cd was observed in secondary lysosomes associated with MT deposits in their exocytotic residual bodies. The results demonstrated that, in contrast to the case with high-dose Cd-administration, renal toxicity is not induced by long-term oral administration of low amounts of Cd, although tissue accumulation does occur. Possible protective mechanisms may be operating.

Randomized trial of vigabatrin in patients with infantile spasms

BACKGROUND

Infantile spasms are a rare but devastating pediatric epilepsy that, outside the United States, is often treated with vigabatrin. The authors evaluated the efficacy and safety of vigabatrin in children with recent-onset infantile spasms.

METHODS

This 2-week, randomized, single-masked, multicenter study with a 3- year, open-label, dose-ranging follow-up study included patients who were younger than 2 years of age, had a diagnosed duration of infantile spasms of no more than 3 months, and had not previously been treated with adrenocorticotropic hormone, prednisone, or valproic acid. Patients were randomly assigned to receive low-dose (18-36 mg/kg/day) or high-dose (100-148 mg/kg/day) vigabatrin. Treatment responders were those who were free of infantile spasm for 7 consecutive days beginning within the first 14 days of vigabatrin therapy. Time to response to therapy was evaluated during the first 3 months, and safety was evaluated for the entire study period.

RESULTS

Overall, 32 of 142 patients who were able to be evaluated for efficacy were treatment responders (8/75 receiving low-dose vigabatrin vs 24/67 receiving high doses, p < 0.001). Response increased dramatically after approximately 2 weeks of vigabatrin therapy and continued to increase over the 3-month follow-up period. Time to response was shorter in those receiving high-dose versus low-dose vigabatrin (p = 0.04) and in those with tuberous sclerosis versus other etiologies (p < 0.001). Vigabatrin was well tolerated and safe; only nine patients discontinued therapy because of adverse events.

CONCLUSIONS

These results confirm previous reports of the efficacy and safety of vigabatrin in patients with infantile spasms, particularly among those with spasms secondary to tuberous sclerosis.

Protective effect of SM-20550, a selective Na+ - H+ exchange inhibitor, on ischemia-reperfusion-injured hearts

The protective effects of Na+ - H+ exchange inhibitors SM-20550 (SM) and 5-(N-ethyl-N-isopropyl)-amiloride (EIPA) against ischemia-reperfusion injury were investigated in guinea pig Langendorff hearts. The changes in intracellular pH (pHi), high-energy phosphates, and biologic intracellular active ions ([Na+]i and [Ca2+]i) were regarded using the 31P-NMR and specific fluorescent signals from the heart tissues together with simultaneous recordings of the left ventricular developed pressure (LVDP). The recovery rate of LVDP from ischemia (40 min) by reperfusion was 36.8% in the control experiments, whereas in the presence of SM 10(-7) M, a gradual increase to 75.9% (55.5% with 10(-8) M), in contrast to EIPA (10(-7) M), 47.5% was observed. SM 10(-7) M restored the ATP level by 70% in 40-min reperfusion, which was already higher than the control in the latter half (20-40 min) of the ischemic period. The recovery rate of phosphocreatine by pretreatment of the heart with SM 10(-7) M was 75% in 40 min reperfusion. The pHi estimated from Pi/phosphocreatine chemical shift became highly acidic in ischemic heart so that SM 10(-7) M caused slight but significant pHi reduction from control pHi of 5.89 to 5.75. The level returned to pHi at around 7.38 during 30-40 min reperfusion, and the recovery was significantly greater than the control pHi of 7.24. The fura-2 Ca2+ or SBFI-Na+ signals during Langendorff ischemia heart increased, and rapidly returned to the control level after the reperfusion. SM suppressed the [Na+]i or [Ca2+]i elevation induced in the late stage during ischemia, resulting in LVDP restoration after reperfusion; Diastolic Ca2+ in the end period of ischemia, SM 10(-7) M 194% versus drug-free 220.7%. Na+: SM 10(-7) M 121.6% versus drug-free 128.0%. The present results suggest that the selective Na+ - H+ exchange inhibitor SM is promising as a potent and specific protective agent against ischemia-reperfusion injuries with Ca2+ overload induced via Na+ - H+, Na+ - Ca2+ exchange.

Molecular cloning, expression and tissue distribution of hamster diacetyl reductase. Identity with L-xylulose reductase

Using rapid amplification of cDNA ends PCR, a cDNA species for diacetyl reductase (EC 1.1.1.5) was isolated from hamster liver. The encoded protein consisted of 244 amino acids, and showed high sequence identity to mouse lung carbonyl reductase and hamster sperm P26h protein, which belong to the short-chain dehydrogenase/reductase family. The enzyme efficiently reduced L-xylulose as well as diacetyl, and slowly oxidized xylitol. The K(m) values for L-xylulose and xylitol were similar to those reported for L-xylulose reductase (EC 1.1.1.10) of guinea pig liver. The identity of diacetyl reductase with L-xylulose reductase was demonstrated by co-purification of the two enzyme activities from hamster liver and their proportional distribution in other tissues.

Enzymatic characteristics and subcellular distribution of a short-chain dehydrogenase/reductase family protein, P26h, in hamster testis and epididymis

A hamster sperm 26 kDa protein (P26h) is strikingly homologous with mouse lung carbonyl reductase (MLCR) and is highly expressed in the testis, but its physiological functions in the testis are unknown. We show that recombinant P26h resembles NADP(H)-dependent MLCR in the tetrameric structure, broad substrate specificity, inhibitor sensitivity, and activation by arachidonic acid, but differs in a preference for NAD(H) and high efficiency for the oxidoreduction between 5alpha-androstane-3alpha,17beta-diol (k(cat)/K(M) = 243 s(-1) mM(-1)) and 5alpha-dihydrotestosterone (k(cat)/K(M) = 377 s(-1) mM(-1)). The replacement of Ser38-Leu39-Ile40 in P26h with the corresponding sequence (Thr38-Arg39-Thr40) of MLCR led to a switch in favor of NADP(H) specificity, suggesting the key role of the residues in the coenzyme specificity. While the P26h mRNA was detected only in the testis of the mature hamster tissues, its enzyme activity was found mainly in the mitochondrial fraction of the testis and in the nuclear fraction of the epididymis on subcellular fractionation, in which a mitochondrial enzyme, isocitrate dehydrogenase, exhibited a similar distribution pattern. The enzyme activity of P26h in the two tissue subcellular fractions was effectively solubilized by mixing with 1% Triton X-100 and 0.2 M KCl, and enhanced more than 10-fold. The enzymes purified from the two tissue fractions exhibited almost the same structural and catalytic properties as those of the recombinant P26h. These results suggest that P26h mainly exists as a tetrameric dehydrogenase in mitochondria of testicular cells and plays a role in controlling the intracellular concentration of a potent androgen, 5alpha-dihydrotestosterone, during spermatogenesis, in which it may be incorporated in mitochondrial sheaths of spermatozoa.

Effects of ingestion of cadmium-polluted rice or low-dose cadmium-supplemented diet on the endogenous metal balance in female rats

The concentrations of endogenous metal ions in liver, kidney, and bone tissues of female rats were measured after ingestion of cadmium-polluted rice (1.24 ppm as Cd) or cadmium-supplemented rice (1.24 and 4.96 ppm) for 2 or 4 mo. The metal accumulated mainly in the kidneys and in the liver. The concentration of cadmium (Cd) in the kidneys of rats fed a 1.24-ppm Cd-supplemented diet was significantly higher than in the Cd-polluted rice group. After 2 mo, the levels of iron and sodium in the liver were elevated in the Cd-polluted rice group, but not in the 1.24-ppm Cd-supplemented group, as compared to controls. The zinc concentration in the Cd-polluted rice group was decreased. The concentration of copper in the kidneys was increased for all Cd-containing diet groups. After 4 mo, the effects of Cd on essential metals in the Cd-polluted and 1.24-ppm Cd-supplemented groups had almost disappeared, although several metal ions in selected organs in the 4.96-ppm Cd-supplemented group showed more prominent changes than in the group exposed for 2 mo. These results suggest that the effects of short-term exposure to Cd on essential metal balance are stronger for rice-bound Cd than for inorganic Cd, although the absorption rate of Cd in Cd-polluted rice may be lower than that of cadmium chloride added to rice.

Assessment of renal toxicity by analysis of regeneration of tubular epithelium in rats given low-dose cadmium chloride or cadmium-polluted rice for 22 months

To determine whether low-dose oral administration of cadmium (Cd) induces renal toxicity, six groups of female Sprague-Dawley rats were fed a diet containing low amounts of CdCl2 or Cd-polluted rice at concentrations up to 40 ppm, and were killed after 12, 18, and 22 months (experiment 1). In addition to the determination of cortical Cd levels and histopathological assessment of kidneys, labeling indices (LIs) for proliferating cell nuclear antigen (PCNA) in the renal cortical tubular epithelium of Cd-treated rats were determined as a measure of regenerative activity. For comparison, the kidneys of rats given diets containing small to large amounts of CdCl2 up to 600 ppm for 4 months were similarly examined (experiment 2). Animals in experiment 1 demonstrated spontaneous chronic nephropathy and fluctuation in the tubular PCNA LI, but these findings were not correlated with renal Cd levels at 22 months. PCNA LI on the other hand, appeared to be linked to the severity of chronic nephropathy. In experiment 2, levels of CdCl2 of 200 ppm or more clearly induced degeneration and apoptosis of proximal tubules with high correlations between renal Cd levels, PCNA LI, and the severity of tubular degeneration. The results demonstrated that, in contrast to high-dose Cd administration, treatment with 40 ppm or less for 22 months did not influence tubular regeneration as a component of nonspecific chronic nephropathy, suggesting that long-term oral administration of low levels of Cd does not injure renal tubules in female rats.

Effects of cadmium administration on the endogenous metal balance in rats

The concentrations of cadmium and other metal ions in selected organs, urine, and blood of female rats were measured after exposure to cadmium chloride through their diet or by oral or intravenous administration. The hematological and urinary variations were followed for 4 wk. Body weight gain and the weights of livers and kidneys from all treated groups were not significantly different from the controls. No gross morphological changes were observed in any of the tissues studied at necropsy. The accumulation of cadmium occurred in the liver and kidney. The zinc levels in these organs were elevated relative to controls, in all treated groups regardless of dose and exposure route. Copper was elevated in the liver, kidney, bone, and blood of animals subject to intravenous administration of cadmium. Hepatic iron was decreased in the dietary and orally treated groups, but was not affected in the intravenous study group. The level of magnesium in kidney was increased for all exposure routes, but that of liver was increased only in the intravenously injected groups. The changes in the concentrations of sodium, potassium, calcium, and phosphorus did not follow a specific pattern and varied from organ to organ, depending on the exposure route. The discussion includes a relationship between tissue injury and the alteration of tissue essential element concentrations.