Numerical study of nano-biofilm stagnation flow from a nonlinear stretching/shrinking surface with variable nanofluid and bioconvection transport properties

A mathematical model is developed for stagnation point flow toward a stretching or shrinking sheet of liquid nano-biofilm containing spherical nano-particles and bioconvecting gyrotactic micro-organisms. Variable transport properties of the liquid (viscosity, thermal conductivity, nano-particle species diffusivity) and micro-organisms (species diffusivity) are considered. Buongiorno's two-component nanoscale model is deployed and spherical nanoparticles in a dilute nanofluid considered. Using a similarity transformation, the nonlinear systems of partial differential equations is converted into nonlinear ordinary differential equations. These resulting equations are solved numerically using a central space finite difference method in the CodeBlocks Fortran platform. Graphical plots for the distribution of reduced skin friction coefficient, reduced Nusselt number, reduced Sherwood number and the reduced local density of the motile microorganisms as well as the velocity, temperature, nanoparticle volume fraction and the density of motile microorganisms are presented for the influence of wall velocity power-law index (m), viscosity parameter [Formula: see text], thermal conductivity parameter (c4), nano-particle mass diffusivity (c6), micro-organism species diffusivity (c8), thermophoresis parameter [Formula: see text], Brownian motion parameter [Formula: see text], Lewis number [Formula: see text], bioconvection Schmidt number [Formula: see text], bioconvection constant (σ) and bioconvection Péclet number [Formula: see text]. Validation of the solutions via comparison related to previous simpler models is included. Further verification of the general model is conducted with the Adomian decomposition method (ADM). Extensive interpretation of the physics is included. Skin friction is elevated with viscosity parameter ([Formula: see text] whereas it is suppressed with greater Lewis number and thermophoresis parameter. Temperatures are elevated with increasing thermal conductivity parameter ([Formula: see text] whereas Nusselt numbers are reduced. Nano-particle volume fraction (concentration) is enhanced with increasing nano-particle mass diffusivity parameter ([Formula: see text]) whereas it is markedly reduced with greater Lewis number (Le) and Brownian motion parameter (Nb). With increasing stretching/shrinking velocity power-law exponent ([Formula: see text] skin friction is decreased whereas Nusselt number and Sherwood number are both elevated. Motile microorganism density is boosted strongly with increasing micro-organism diffusivity parameter ([Formula: see text]) and Brownian motion parameter (Nb) but reduced considerably with greater bioconvection Schmidt number (Sc) and bioconvection Péclet number (Pe). The simulations find applications in deposition processes in nano-bio-coating manufacturing processes.

Modeling magnetic nanopolymer flow with induction and nanoparticle solid volume fraction effects: Solar magnetic nanopolymer fabrication simulation

A mathematical model is presented for the nonlinear steady, forced convection, hydromagnetic flow of electro-conductive magnetic nanopolymer with magnetic induction effects included. The transformed two-parameter, non-dimensional governing partial differential equations for mass, momentum, magnetic induction and heat conservation are solved with the local non-similarity method subject to appropriate boundary conditions. Keller’s implicit finite difference “box” method is used to validate solutions. Computations for four different nanoparticles and three different base fluids are included. Silver nanoparticles in combination with various base fluids enhance temperatures and induced magnetic field and accelerate the flow. An elevation in magnetic body force number decelerates the flow, whereas an increase in magnetic Prandtl number elevates the magnetic induction. Furthermore, increasing nanoparticle solid volume fraction is found to substantially boost temperatures. Applications of the study arise in advanced magnetic solar nanomaterials (fluids) processing technologies.

Stratification of Integrated Cancer Center in Indonesia to Improve the Access to Care

Background and context: Indonesia as one of the low- and middle-income countries has not had a classification of cancer services yet. This classification will be very important for standardization and equalization of cancer services for all Indonesian people to access the cancer services provided. Based on Social Security Administering Agency of Health report, advanced stage of cancer have absorbed ∼17% national health budget (the third largest in financing National Health Insurance) but the outcome of the services still not good enough. Dharmais National Cancer Center (NCC) has the task of establishing cancer services system in stages throughout Indonesia by arrange the cancer services strata in Indonesia and develop its roadmap of achievement to improve the access to care. Aim: To build the stratification of integrated cancer center (ICC) in Indonesia by Health Ministerial Decree to improve access to care as a part of cancer control planning. Strategy/Tactics: 1. Build the concept of integrated cancer center stratification in Indonesia by assess the instrument of Director General of Health Services, Ministry of Health that conduct a comprehensive stratification of cancer services especially for diagnostic radiology services, nuclear medicine and radiotherapy to support the cancer services development plan in Indonesia. Currently, internal audit of radiology quality management has been developed by adopt the International Atomic Energy Agency (IAEA) standards issue with 3 instruments used to assess the radiology quality management, namely: a. Quality Assurance Audit for Diagnostic Radiology Improvement and Learning (QUAADRIL). b. Quality Management Audits in Nuclear Medicine Practices (QUANUM). c. Quality Assurance Team of Radiation Oncology (QUATRO). 2. Conducted an audience with Minister of Health to present the concept of integrated cancer center stratification in Indonesia and to initiate Ministry of Health decree as a regulation. The decree will be follow up by disseminate to all national, provincial and regional referral hospitals so they will have internal audit by IAEA to be mapping. Program/Policy process: 1. Dharmais NCC offer a model of cancer referral networking capabilities as a part of integrated national referral systems that includes preventive, promotive, curative and rehabilitative services for various levels of health care facilities with level strata as ICC strata 1, strata 2, strata 3 and NCC. 2. Encouraging the immediate issuance of Ministry of Health policy in the form of decree or regulation as the legal aspects of implementation. Outcomes: The Minister of Health agree with the proposed stratification of integrated cancer center and process the ministerial decree. What was learned: The stratification of integrated cancer center in Indonesia is very important needed to promote the NCCP especially in access to care so the cancer cases will find and treat in early stage due to closer access.

Site-Specific Lung Cancer to Support National Cancer Control Programs in Indonesia

Background: Lung cancer surely increased particularly in developing country that has double burden of disease because of epidemiologic transition effected high incidence in productive age and premature death. Indonesia as a developing country has better life expectancy but there aren't national cancer control yet. National cancer registry as one of pivotal tools in priority setting of national cancer control. Aim: Epidemiology pattern of lung cancer based on National Cancer Registry to determine national cancer control programs. Methods: In 2016 Ministry of Health assigned 14 provinces (26 cities/districts) in Indonesia to enforce population-based cancer registry and Dharmais as a National Cancer Centre. All health facilities sent data to the National Referral Hospitals in each provinces which Canreg5 were used, year 2008-2012. Data from 14 National Referral Hospitals sent to Dharmais NCC for analysis. Results: Lung cancer posed in the first rank for male and the sixth rank for female by comparison 2:1. Peak incidence occurs in age group of 55 years for male meanwhile 50 years for female. However escalation of cases began in age group of 35 years for both sexes. Three provinces which have high incidence for lung cancer were Bali, South Sumatera and DKI Jakarta as capital city of Indonesia. Adenocarcinoma as the most common histology type. Despite most valid percentage and coverage from each province still quite low. Conclusion: Lung cancer become the first priority for cancer control program in male foremost three provinces. This issue highlighted and need further analysis to assess risk factor.

Epidemiology of Childhood Cancer in Indonesia: Study of 14 Population Based Cancer Registries

Background: Childhood cancer was about 3%-5% cases of all cases. Dharmais National Cancer Hospital was pointed out by Ministry of Health as National Quality Control of Cancer Burden Data in 2016. To provide national cancer burden data, Ministry of Health established 14 population based cancer registries in 2016, located in 14 provinces in Indonesia. The coverage area was 26 districts/municipalities in each selected provinces with total coverage number of population was 14% of Indonesia. Aim: This study was to describe quality data of 14 population based cancer registries in Indonesia and to describe the epidemiology of childhood cancer during 2008-2012. Methods: We used 14 population based cancer registries data that collected in Office of National Quality Control of Cancer Burden Data, Dharmais National Cancer Center, within age 0-19 years old during 2008-2012. We analyzed quality data of 14 population based cancer registries data based on WHO-IARC rules for cancer registry data. Results: There were 4156 cases. The average of percentage microscopic verification was 59%, 7 out of 7 provinces had lower percentage of microscopic verification. The highest was South Sulawesi (98%) followed by Central Java (92.9%), and East Borneo (79.4%). Most of them had over 25% of DCO. DKI Jakarta had the highest incidence age-standardized rate (7.1) followed by Bali (4.9) and North Sulawesi (4.8). The most frequent childhood cancer cases were in male (57%), between 10-14 years old. Both in male and female had similar rank of the most frequent cases, other malignant epithelial (22.4%: 17.2%), leukemia (19.3%: 14.3%), and other and unspecified malignant tumor (9.4%: 8.4%). Conclusion: The coverage and quality data of childhood cancer in 14 population based cancer registries data were low. Each population based cancer registries should improve the process of cancer registration.

Profile of Colorectal Cancer in 14 Provinces in Indonesia

Background: In Indonesia, the incidence of colorectal cancer was separated in colon and rectum cancer. The incidence of rectum cancer ranked number five in male and number eight in female. The incidence of colon cancer ranked number seven in male and number nine in female. Aim: The aim of this study is to know the profile of colorectal cancer in Indonesia. Methods: Using data collected from population based cancer registry in 14 provinces (26 cities/districts) in Indonesia which was developed into a site specific cancer registry. All of the data diagnosed from 2008-2012. The classification of cases is used WHO criteria, ICD-O-3 (C18-C20). There were 3453 patients included in this study. CanReg5 was used as the software for entry and analyze the data. All primary health care and hospitals sent the data to the 14 National Referral Hospitals which located in each provinces. Finally, the 14 National Referral Hospitals sent the data to Dharmais National Cancer Center. Results: Incidence of colorectal cancer was higher in male (54%) than female (46%). Peak cancer cases occurred in the age of 50-54 years. DKI Jakarta, Central Java, DIY Yogyakarta as the three provinces which have highest incidence for colorectal cancer. The highest microscopic verification was in Papua, Central Java, and South Sulawesi. The highest percentage location was in the colon. The type of morphology was adenocarcinoma. Conclusion: The incidence of colon cancer entered in the top ten most common cancers in Indonesia. The quality of data still needed to be improved.

Epidemiology of Female Breast Cancer in West Jakarta, Indonesia

Background: Breast cancer was the most common cancer in the world. GLOBOCAN 2012 estimated the incidence of female breast cancer in Indonesia was 40.3 per 100,000 and the mortality rate was 16.6 per 100,000. In 2016, Dharmais National Cancer Center was appointed as Regional Population Based Cancer Registry in West Jakarta. West Jakarta was a municipality with 2,281,945 populations, being the 2nd largest population in DKI Jakarta Province. Aim: This study was to evaluate the quality of population based cancer registry data and to describe the epidemiology of female breast cancer in West Jakarta, Indonesia during 2008-2012 and to compare with GLOBOCAN 2012 . Methods: We used population based cancer registry data with ICD - O code C50.0-C50.9 in female who live in West Jakarta. The population based cancer registry data were collected in Dharmais National Cancer Center. We evaluated the quality of population based cancer registry data based on WHO-IARC rules for cancer registry data. Results: The quality of population based cancer registry data were microscopic verification (70%); DCO percentage (20.8%), and unknown age (0%). The trend of female breast cancer was increasing during 2008-2012. Age-standardized rate incidence was 19.3 per 100,000. The most of frequent were in 45-49 years old, not other specific location subtopography (81.5%), the histopathology type was ductal and lobular neoplasm (51.8%), in stage III (44%), and with metastases to bone (34%). The average of length of duration was 29.1 months, most of them were unknown of last status contact (84%). Conclusion: The coverage and quality data of West Jakarta population based cancer registry need to be increased and establish a follow-up system to decrease the unknown last contact status of patients.

Increase Coverage Cancer Registry by Strengthening and Improving the Reporting of Breast Cancer Screening Program in Jakarta as One of Data Source

Background and context: Breast cancer screening programs by mobile mammography have been done since 2005 for Jakarta and around by collaboration of Dharmais National Cancer Center with The Indonesia Breast Cancer Foundation and Jakarta Health Department. Every activity, mobile mammography has been examined 50 persons for 60-80 times yearly. For 2015 there were 3493 examinations with 529 cases (15.1%) were abnormal which 43 from that cases (8.1%) are suspect malignancy. All that data were compile with early detection and cancer registry data to know the real cancer, but there were no malignancy and only 15 benign cases had come to follow-up to Dharmais NCC. The result is no malignancy. To compile the mobile mammography data with detection unit and cancer registry data were difficult because of the difference terms of the variables. National Cancer Registry of Indonesia has been announced by Ministry of Health since 2016. The coverage of cancer that diagnosed in 2008-2012 in Jakarta just 30.7%. One of the sources of data are screening data. In Indonesia, screening programs for breast and cervix cancer have been done sporadically, including at Jakarta. Unfortunately for 2008-2012 diagnose year, there were no data can compile to cancer registry because there were no address data and name. So we collaborate to improve the data variables for cancer registration system. Aim: To conduct the mobile mammography screening data as one of the sources data for cancer registration to improve the coverage in Jakarta and to prepare the breast specific cancer registry system. Strategy/Tactics: Cancer Registry, Early Detection, Radiology and Pathology Unit was collaborating with The Indonesia Breast Cancer Foundation to improve the variables. Program/Policy process: We to improve the variables and their operational definition especially for name, address and birth date include risk factors and physical examinations variables. The palpations of breast was conduct by midwives or doctors before the examination with mammography. Cancer registration variables definition is the standard, so the name variable is the name that written in the National Identity Card, include the birth date and address. Information system department in Dharmais NCC has made the program to this data system and have been take place since July 2017. Outcomes: There were 1462 data that have been in hospital data based for mobile mammography with 237 cases (16.2%) were abnormal which 14 cases (5.9%) are suspect malignancy. Only 5 suspect malignancy cases had more examination in Dharmais NCC and all of them were diagnosed breast malignancy. What was learned: Standardization of variable definitions is very important for cancer registry data source to improve the coverage especially for early stage finding cases. But to know the standard diagnose and to follow the cases real conditions, we have to make a good and clear referral system networking.

Unsteady electromagnetic radiative nanofluid stagnation-point flow from a stretching sheet with chemically reactive nanoparticles, Stefan blowing effect and entropy generation

This article investigates the combined influence of nonlinear radiation, Stefan blowing and chemical reactions on unsteady electro-magneto-hydrodynamic stagnation-point flow of a nanofluid from a horizontal stretching sheet. Both electrical and magnetic body forces are considered. In addition, the effects of velocity slip, thermal slip and mass slip are considered at the boundaries. An analytical method named as homotopy analysis method is applied to solve the non-dimensional system of nonlinear partial differential equations which are obtained by applying similarity transformations on governing equations. The effects of emerging parameters such as Stefan blowing parameter, electric parameter and magnetic parameter on the important physical quantities are presented graphically. In addition, an entropy generation analysis is provided in this article for thermal optimization. The flow is observed to be accelerated both with increasing magnetic field and electrical field. Entropy generation number is markedly enhanced with greater magnetic field, electrical field and Reynolds number, whereas it is reduced with increasing chemical reaction parameter.

Migrant children's health problems, care needs, and inequalities: European primary care paediatricians' perspective

BACKGROUND

Primary care paediatricians' perception of migrant children's health in Europe has not been explored before. Our aim was to examine European paediatricians' knowledge on migrant children's health problems, needs, inequalities, and barriers to access health care.

METHODS

European primary care paediatricians were invited by the European Academy of Paediatrics Research in Ambulatory Setting Network country coordinators to complete a web-based survey concerning health care of migrant children. A descriptive analysis of all variables was performed.

RESULTS

The survey was completed by 492 paediatricians. Sixty-three per cent of the respondents reported that the general health of migrant children is worse than that of nonmigrants, chronic diseases cited by 66% of the respondents as the most frequent health problem. Sixty-six per cent of the paediatricians reported that migrant children have different health needs compared to nonmigrant children, proper oral health care mentioned by 86% of the respondents. Cultural/linguistic factors have been reported as the most frequent barrier (90%).to access health care. However, only 37% of providers have access to professional interpreters and cultural mediators. Fifty-two per cent and 32% do not know whether one or more of the family members are undocumented and whether they are refugees/asylum seekers, respectively. Updated guidelines for care of migrant children are available for only 35% of respondents, and 80% of them have not received specific training on migrant children's care.

CONCLUSIONS

European primary care paediatricians recognize migrant children as a population at risk with more frequent and specific health problems and needs, but they are often unaware of their legal state. Lack of interpreters augments the existing language barriers to access proper care and should be solved. Widespread lack of guidelines and specific providers' training should be addressed to optimize health care delivery to migrant children.

Implementation of an in-patient pediatric mortality reduction intervention, Gondar University Hospital, Ethiopia

SETTING

Gondar University Hospital (GUH) is a resource-limited tertiary care hospital in northern Ethiopia.

OBJECTIVE

To evaluate the aggregate effect of care standardization, institutional guidelines, and simulation-based training on pediatric mortality at a resource-limited hospital.

DESIGN

Uncontrolled pre-post study. GUH in-patients aged from 30 days to 14 years were included in the program evaluation (baseline 11 September-18 November 2010; intervention 19 September-9 December 2011). Interns attached to the GUH pediatrics department from 6 September to 9 December 2011 were included in the training evaluation. Institution-specific management guidelines were prepared for choking, respiratory distress, dehydration, sepsis, congestive heart failure, coma, and seizure. Approval for the protocols was obtained from each pediatric faculty member. Interns received a 3.5 h simulation-based training in triage, procedural skills, and protocol usage. Primary outcome was overall deaths (%); secondary outcomes were deaths within 24 h of admission (%) and median pre/post-training emergency management test scores (%).

RESULTS

No difference in mortality (OR 0.72, 95%CI 0.40-1.29, P = 0.265) or first 24 h mortality (crude OR 0.97, 95%CI 0.37-2.55) was observed. Trainee examination scores improved from 33% to 74% (P < 0.001).

CONCLUSION

Combining care standardization, management protocols, and simulation-based training did not reduce mortality among pediatric in-patients. Focused, simulation-based training improved short-term test scores among interns.

Corneal changes in type II diabetes mellitus in Malaysia

AIM

To compare corneal endothelial structure and central corneal thickness (CCT) between type II diabetics and non-diabetic control patients. To look for correlations between diabetic status and corneal findings.

METHODS

Hospital-based, observational study. 200 eyes (from 100 type II diabetic patients and 100 controls) were included. Specular microscopy and pachymetry were used to measure endothelial cell density, size, coefficient of variation in cell area, hexagonality as well as corneal thickness. Independent t-tests were used to compare variables between diabetics and controls. Pearson correlation tests were used to evaluate correlations between corneal findings and diabetic status such as duration of diabetes, haemoglobin A1c (HbA1c) level and severity of diabetic retinopathy.

RESULTS

Endothelial cell density in the diabetic group (2541.6±516.4 cells/mm(2)) was significantly lower than that in the control group (2660.1±515.5 cells/mm(2), P<0.05). The average size of endothelial cells, standard deviation (SD) of cell size and coefficient of variation (CV) of cell area were all significantly higher in diabetics. Hexagonality was significantly lower in diabetics (41.1%±19.6%) compared to non-diabetics (45.2%±20.6%). CCT was higher in diabetics but not significant (P>0.05). Duration of diabetes, HbA1c level and severity of diabetic retinopathy were not significantly correlated with corneal endothelial findings.

CONCLUSION

Type II diabetes causes a significant alteration in the state of the cornea including reduction in endothelial cell density and increased pleomorphism and polymegathism. Central corneal thickness is unaffected.

PET imaging of the in vivo brain acetylcholinesterase activity and nicotine binding in galantamine-treated patients with AD

The effect of galantamine treatment on cortical acetylcholinesterase (AChE) activity and nicotinic receptor binding was investigated by positron emission tomography (PET) in 18 patients with mild Alzheimer's disease (AD) in relation to galantamine concentration and the patients' cognitive performances. The first 3 months of the study was of a randomized double-blind placebo-controlled design, during which 12 patients received galantamine (16-24mg/day) and 6 patients the placebo, and this was followed by 9 months' galantamine treatment in all patients. The patients underwent PET examinations to measure cortical AChE activity ((11)C-PMP) and (11)C-nicotine binding. Neuropsychological tests were performed throughout the study. Inhibition (30-40%) of cortical AChE activity was observed after 3 weeks to 12 months of galantamine treatment. No significant change in mean cortical (11)C-nicotine binding was observed during the study. (11)C-Nicotine binding, however, positively correlated with plasma galantamine concentration. Both the changes of AChE activity and (11)C-nicotine binding correlated positively with the results of a cognitive test of attention. In conclusion, galantamine caused sustained AChE inhibition for up to 12 months. At the individual level, the in vivo cortical AChE inhibition and (11)C-nicotine binding were associated with changes in the attention domain of cognition rather than episodic memory.

Publication bias in abstracts presented to the annual meeting of the American Academy of Orthopaedic Surgeons

PURPOSE

To examine possible causes of publication bias in the orthopaedic literature so as to avoid inappropriate clinical decisions based on reviews of the literature.

METHODS

Two reviewers independently reviewed abstracts presented to the 1999 American Academy of Orthopaedic Surgeons annual meeting. Data pertaining to sample size, statistical significance, study setting, country of origin, outcome, study type, and sponsorship were extracted from each abstract. The publication rate was measured after 5 years, by electronic searching and author contact. Predictors of publication were identified using logistic regression analysis.

RESULTS

Of the 318 abstracts listed in the proceedings, 175 (55%) were published within 5 years. Publication was associated with positive rather than neutral outcomes (odds ratio, 1.62; 95% confidence interval, 1.01-2.59; p<0.05) and with the reporting of statistical significance (odds ratio, 2.05; 95% confidence interval 1.24-3.39; p=0.005). Sponsorship, country of origin, sample size, study setting, and study type did not significantly influence the publication rate.

CONCLUSION

Evidence of publication bias exists in abstracts presented at the 1999 American Academy of Orthopaedic Surgeons annual meeting. Clinical decisions based on the literature may be biased due to an over-representation of studies with positive outcomes.

Inhibition of acetylcholinesterase in CSF versus brain assessed by 11C-PMP PET in AD patients treated with galantamine

The relationship between acetylcholinesterase (AChE) activity in the CSF and brain of patients with Alzheimer's disease (AD) was investigated in 18 mild AD patients following galantamine treatment. The first 3 months of the study had a randomized double-blind placebo-controlled design, during which 12 patients received galantamine (16-24 mg/day) and six patients placebo. This was followed by 9 months galantamine treatment in all patients. Activities and protein levels of both the "read-through" AChE (AChE-R) and the synaptic (AChE-S) variants in CSF were assessed in parallel together with the regional brain AChE activity by (11)C-PMP and PET. The AChE-S inhibition was 30-36% in CSF, which correlated well with the in vivo AChE inhibition in the brain. No significant AChE inhibition was observed in the placebo group. The increased level of the AChE-R protein was 16% higher than that of AChE-S. Both the AChE inhibition and the increased level of AChE-R protein positively correlated with the patient's performance in cognitive tests associated with visuospatial ability and attention. In conclusion, AChE levels in CSF closely mirror in vivo brain AChE levels prior to and after treatment with the cholinesterase inhibitors. A positive cognitive response seems to dependent on the AChE inhibition level, which is balanced by an increased protein level of the AChE-R variant in the patients.

Differential CSF butyrylcholinesterase levels in Alzheimer's disease patients with the ApoE epsilon4 allele, in relation to cognitive function and cerebral glucose metabolism

Butyrylcholinesterase (BuChE) is increased in the cerebral cortex of Alzheimer's disease (AD) patients, particularly those carrying epsilon4 allele of the apolipoprotein E gene (ApoE) and certain BuChE variants that predict increased AD risk and poor response to anticholinesterase therapy. We measured BuChE activity and protein level in CSF of eighty mild AD patients in relation to age, gender, ApoE epsilon4 genotype, cognition and cerebral glucose metabolism (CMRglc). BuChE activity was 23% higher in men than women (p<0.03) and 40-60% higher in ApoE epsilon4 negative patients than in those carrying one or two epsilon4 alleles (p<0.0004). CSF BuChE level correlated with cortical CMRglc. Patients with high to moderate CSF BuChE showed better cognitive function scores than others. We hypothesize that CSF BuChE varies inversely with BuChE in cortical amyloid plaques. Thus, low BuChE in a patient's CSF may predict extensive incorporation in neuritic plaques, increased neurotoxicity and greater central neurodegeneration.

In vivo responses to antimalarials by Plasmodium falciparum and Plasmodium vivax from isolated Gag Island off northwest Irian Jaya, Indonesia

There is renewed interest in the rich nickel and cobalt deposits of Pulau Gag, an isolated but malarious island off the northwest coast of Irian Jaya. In preparation for an expanded workforce, an environmental assessment of malaria risk was made, focusing upon malaria prevalence in the small indigenous population, and the in vivo sensitivity of Plasmodium falciparum and P. vivax to chloroquine (CQ) and sulfadoxine/pyrimethamine (S/P), the respective first- and second-line drugs for uncomplicated malaria in Indonesia. During April-June 1997, mildly symptomatic or asymptomatic malaria infections were found in 24% of 456 native residents. Infections by P. falciparum accounted for 60% of the cases. Respective day 28 cure rates for CQ (10 mg base/kg on days 0 and 1; 5 mg/kg on day 2) in children and adults were 14% and 55% (P < 0.005). Type RII and RIII resistance characterized only 5% of the CQ failures. Re-treatment of 36 P. falciparum CQ treatment failures with S/P (25 mg/kg and 1.25 mg/kg, respectively) demonstrated rapid clearance and complete sensitivity during the 28-day follow-up period. More than 97% of the P. vivax malaria cases treated with CQ cleared parasitemia within 48 hr. Three cases of P. vivax malaria recurred between days 21 and 28, but against low drug levels in the blood. The low frequency of RII and RIII P. falciparum resistance to CQ, the complete sensitivity of this species to S/P, and the absence of CQ resistance by P. vivax are in contrast to in vivo and in vitro test results from sites on mainland Irian Jaya.

Conduction velocity versus amplitude analysis: evidence for demyelination in diabetic neuropathy

Motor conduction velocities (CVs) were correlated with distal compound muscle action potential (CMAP) amplitudes for tibial, peroneal, and median nerves in patients with biopsy-proven chronic inflammatory demyelinating polyneuropathy (CIDP), diabetic neuropathy, and amyotrophic lateral sclerosis. Only in the diabetic patients did CV significantly correlate with CMAP amplitude. The data show that diabetic neuropathy produces conduction velocity slowing that cannot be explained by axon loss alone, and that differentiation between diabetic neuropathy and CIDP in an individual nerve is difficult.

Direct influence of temperature on the semicircular canal receptor

Effect of thermal stimulus on the vestibular receptor was studied using the isolated frog semicircular canal. The posterior (PSC) and lateral semicircular canals (LSC) were placed in the horizontal plane in frog Ringer's solution. The ampullary nerve was sucked into a glass suction electrode to record compound potentials. The steel thermal probe was positioned next to the ampullary surface to give thermal stimuli. When the PSC ampulla was cooled, the spontaneous discharge markedly increased. When the PSC ampulla was warmed, the discharge decreased. When the LSC ampulla was cooled, the discharge increased in the same manner as in the PSC. Also, warming of the LSC decreased the discharge in the same manner as in the PSC. The cupula was removed from the crista in order to eliminate the effect of volume change of the endolymph. The results were comparable to those with intact cupula in both the PSC and LSC. Cooling increased, while warming decreased the discharge. These responses are possibly due to a mechanism other than mechanical volume change, because the PSC and LSC yielded the same type of responses. Direct temperature reaction of the vestibular hair cell was suggested.

Effect of streptomycin intoxication on vestibular nerve regeneration and posture recovery

The action of streptomycin sulfate (SM) on the regenerative process of the vestibular nerve and posture recovery was studied, using bull frogs. The vestibular nerve was sectioned in various conditions with intact endorgan or with SM intoxication. When the nerve was sectioned with the hair cells left intact, the nerve regenerated well and body balance recovered to normal. However, when neural regeneration was blocked, recovery was incomplete. SM intoxication resulted in various degrees of hair cell damage. Degree of posture recovery correlated well with the number of hair cells. When the nerve was sectioned after damaging the hair cell, the nerve failed to regenerate and posture recovery was incomplete. These results suggest that the degree of posture recovery depends on hair cell function and neural regeneration. Furthermore, neural regeneration is strongly influenced by hair cell function.

A study on temperature dependent vestibular potential: effect of long lasting thermal stimulus and aminoglycoside agent

Effect of temperature changes on the vestibular receptor was studied using isolated posterior semicircular canals (PSC) of bull frogs. Cupula was removed from the crista. PSC was placed in the inner compartment of the double chamber. Warm or cool water was filled in the outer compartment to change the temperature of the inner compartment. Changes of the spontaneous discharge were recorded from the ampullary nerve. When cooled, the discharge temporarily increased, followed by a gradual decrease. When warmed, it temporarily decreased and then increased, forming response curves of a mirror image. After addition of streptomycin, the temperature dependent response disappeared. These results suggest that the semicircular canal receptor is activated by direct temperature effects.

Phenylbutazone pharmacokinetics and bioavailability in the dromedary camel (Camelus dromedarius)

Phenylbutazone was administered intravenously and intramuscularly at a dosage rate of 4.4 mg/kg to a group of 6 female camels in a two-period crossover study. After intravenous (i.v.) administration, disposition was characterised by a two-compartment open model, with a low volume of distribution (0.174 l.kg-1), and distribution and elimination half-lives of 0.43 and 12.51 h, respectively. After intramuscular (i.m.) dosing absorption was relatively rapid with absorption half-time and time of maximal concentration values of 1.14 and 3.95 h, respectively. Plateau concentrations of phenylbutazone in plasma were obtained between 2 and 12 h and mean bioavailability was 97%, although this was subject to wide inter-animal differences. Plasma concentrations of the phenylbutazone metabolite, oxyphenbutazone, were low after iv dosing and generally undetectable after im administration, indicating that it is unlikely to contribute significantly to the pharmacological effects produced by phenylbutazone administration. An indication was obtained that phenylbutazone inhibited the ex vivo synthesis of serum thromboxane B2 (TxB2) for 24h after i.v. dosing, but this finding requires confirmation.

The origin of thermally evoked vestibular potential

The origin of the thermally evoked ampullary nerve action potential was searched using isolated frog posterior semicircular canal (PSC). The PSC was placed in the dish with 2 chambers separating endo- and perilymphatic fluid. Cooling stimulus was given by approximating the iced bar to the ampulla, and induced action potential (CAP) was recorded. When only the endolymph contained Ca2+, no CAP was evoked, while, the perilymph contained Ca2+, CAP was observed. These findings were comparable between with and without cupula. When only the endolymph contained tobramycin (TOB), the spike count did not change. However, when TOB was added into the perilymph, the spike count decreased according to concentration of TOB. When TOB was washed out, the spike count recovered. These findings were also comparable between with and without cupula. The above results indicate that thermally evoked vestibular potentials possibly originate in the hair cell.

Functional model of benign paroxysmal positional vertigo using an isolated frog semicircular canal

Bull frogs posterior semicircular canals (psc) wee used to simulate the condition of benign paroxysmal positional vertigo (BPPV). The psc was isolated in frog Ringer's solution, and the saccular otoconia were used as a responsible material to stimulate the cupula. When the otoconia were placed on the cupular surface to mimic the condition of cupulolithiasis, the psc ampullary nerve action potentials instantaneously changed according to the direction of the gravity produced by otoconia. When the otoconia were dropped into the canal to mimic the condition of moving otoconia in the canal, the action potentials changed together with the otoconial flow after a latent period. Both cupulolithiasis and moving otoconia are possibly valid mechanisms of BPPV, since they effectively stimulate the cupula. However, moving otoconia with a latent period would better explain clinical features of BPPV.

Experimental model of vertigo induced by detached otoconia

Isolated posterior semicircular canals (psc) of bull frogs were used for a model of positional vertigo. Induced ampullary nerve action potentials were recorded. When the cupula was removed and the saccular otoconia were dropped onto the cilia, excitatory, and inhibitory potentials were evoked by changing the psc positions into canal-down and canal-up, respectively. When the otoconia were allowed to stay on the cupular surface, canal-down and canal-up positions also evoked excitatory and inhibitory responses, respectively. When the otoconia were inserted in the canal and were allowed to move, changing the psc positions likewise evoked responses. However, when one end of the canal was closed, these responses disappeared, indicating the efficacy of canal plugging.

Directional excitability of the utricle: a study by thermoconvective stimulation

The frog utricular macula was stimulated by thermoconvective flow in four different directions. The evoked utricular nerve action potentials were recorded via a glass suction electrode. The maximum spikes and the time constants of the potentials were counted. The spike counts and the time constants were not significantly different among stimuli. This suggests that the utricle has the same physiological excitability to any directional stimulus.