2.Parameter estimation for sigmoid E(max) models in exposure-response relationship.
Translational and Clinical Pharmacology 2017;25(2):74-84
The purpose of this simulation study is to explore the limitation of the population PK/PD analysis using data from a clinical study and to help to construct an appropriate PK/PD design that enable precise and unbiased estimation of both fixed and random PD parameters in PK/PD analysis under different doses and Hill coefficients. Seven escalating doses of virtual drugs with equal potency and efficacy but with five different Hill coefficients were used in simulations of single and multiple dose scenarios with dense sampling design. A total of 70 scenarios with 100 subjects were simulated and estimated 100 times applying 1-compartment PK model and sigmoid E(max) model. The bias and precision of the parameter estimates in each scenario were assessed using relative bias and relative root mean square error. For the single dose scenarios, most PD parameters of sigmoid E(max) model were accurately and precisely estimated when the C(max) was more than 85% of EC₅₀, except for typical value and inter-individual variability of EC₅₀ which were poorly estimated at low Hill coefficients. For the multiple dose studies, the parameter estimation performance was not good. This simulation study demonstrated the effect of the relative range of sampled concentrations to EC₅₀ and sigmoidicity on the parameter estimation performance using dense sampling design.
Bias (Epidemiology)
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Clinical Study
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Colon, Sigmoid*
3.The epidemiology of malaria in the Papua New Guinea highlands: 6. Simbai and Bundi, Madang Province.
Ivo Mueller ; Simon Yala ; Moses Ousari ; Julius Kundi ; Rex Ivivi ; Gerard Saleu ; Albert Sie ; John C Reeder
Papua and New Guinea medical journal 2007;50(3-4):123-33
Although predominantly a lowland province, Madang also includes highland areas such as Simbai and Bundi along the northern highland fringe. While the malaria situation in the coastal lowlands has been studied in great detail, the current malaria situation in the highland fringe communities has not been studied in depth since the 1960s. A series of recent malariological surveys found that the malaria situation has changed little over the last 40 years in both Simbai and Bundi. In the Simbai area there is little malaria transmission in villages above 1400 m, with a prevalence rate (PR) of 2.5-4.2%. Below 1400 m, however, there is moderate to high transmission (PR 8.6-24.7%) with surprisingly little difference in prevalence rates between survey villages, despite large differences in altitude. Prevalence rates of malaria infection were low in all Bundi villages (2.5-8.5%) with most infections occurring in adolescents and adults, which indicates limited acquisition of effective immunity to malaria and the possibility that many infections are acquired when travelling to the highly malarious lowlands area. Based on spleen rates the lower Simbai area would be regarded as mesoendemic, and the upper Simbai and Bundi areas as hypoendemic. Only in the lower Simbai area is malaria a major cause of febrile illness. However, in all areas village mean haemoglobin (Hb) levels were highly correlated with the prevalence of malaria infections, while concurrent parasitaemia reduced individual Hb levels by 1.3 g/dl (CI95 [1.0-1.5], p < 0.001) and significantly increased the risk for moderate-to-severe anaemia (Hb < 8 g/dl) (adjusted odds ratio 5.6, CI95 [3.6-8.6], p < 0.001). Based on the survey results, areas of different malaria epidemiology are delineated and options for control in each area are discussed.
Malaria
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Study of epidemiology
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Prevalence aspects
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Hemoglobin
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L
4.The epidemiology of shoulder dislocation in a state-hospital: a review of 106 cases.
The Medical journal of Malaysia 2005;60 Suppl C():17-21
This retrospective study was conducted in a state hospital set-up and aimed at identifying the magnitude of shoulder dislocations and their demographic data, characteristics of the injury, mechanism and predisposing factors, and the instituted treatment. Patients with radiographic evidence of shoulder dislocation admitted to the hospital from January 1999 to December 2002 were included. Data were recorded from the case notes. There were 105 shoulder dislocations with male predomination in 77% cases and age ranged between 11 and 90 years (average 30.9 years). The right shoulder was affected in 68% of the cases. The contributing events were fall in 37% of cases, road traffic accident 23%, sports 17% and pathological conditions 13%. Anterior dislocation occurred in 96.2% of the cases. Posterior and inferior dislocations encountered in two patients for each type. Twelve dislocations were associated fracture of the greater tuberosity, two each with humeral neck fracture and cerebral injuries. First time dislocation occurred in 73.6% of the cases. The recurrences ranged between 2 to 6 times (average 3.4 times). Closed manipulative reduction and strapping was the definitive treatment in 92.4% of the cases and the remaining needed surgical reconstruction. Four patients had open reduction and internal fixation of the associated fractures while another four had arthroscopic Bankart's repair. In conclusion, shoulder dislocation represents the most common shoulder problems. It afflicted young adults of reproductive age (21-40 years) and participation in sports was a risk factor in men. Women over 40 years and fall were at risk to develop shoulder dislocation.
Shoulder
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Hospitals
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Study of epidemiology
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seconds
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Reduction (chemical)
6.The epidemiology of malaria in the Papua New Guinea highlands: 2. Eastern Highlands Province.
Ivo Mueller ; Steve Bjorge ; Gimana Poigeno ; Julius Kundi ; Tony Tandrapah ; Ian D Riley ; John C Reeder
Papua and New Guinea medical journal 2003;46(3-4):166-79
The epidemiology of malaria in Eastern Highlands Province (EHP) is characterized by generally very low-level or no local malaria transmission but a considerable risk of epidemics. In non-epidemic situations, parasite prevalence was under 5% in all but one area, Lufa Valley, where P. vivax was the most common parasite (prevalence rate of 58%). During epidemics, however, 23% (range 8-63%) of people were infected, with P. falciparum the predominant parasite. Mixed infections were very common (12%) but P. malariae and P. ovale were rare. Outside epidemics, malaria was only a minor source of febrile illness and enlarged spleens and anaemia (haemoglobin level < 7.5 g/dl) were virtually absent. However, epidemics were associated with a high incidence of relatively severe morbidity, both in terms of fevers and moderate to severe anaemia. Epidemic prevention, surveillance and response therefore are priorities in malaria control in EHP.
Malaria
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upper case pea
;
epidemic aspects
;
Study of epidemiology
;
Parasites
7.Complex patterns of malaria epidemiology in the highlands region of Papua New Guinea.
Ivo Mueller ; John Taime ; Ervin Ibam ; Julius Kundi ; Moses Lagog ; Moses Bockarie ; John C Reeder
Papua and New Guinea medical journal 2002;45(3-4):200-5
A cross-sectional malaria survey of the Pabrabuk area in the Western Highlands Province found that all 4 human malaria species were present in a single village, with an overall parasite prevalence rate of 27%. Plasmodium falciparum was the most frequently detected infection (14%) followed by P. vivax (11%), P. malariae (5%) and P. ovale (3%). 10 of the 51 infections were mixed. Anopheles punctulatus was the most frequent vector species in the area, but both An. farauti no. 6 and An. karwari were also present in low numbers. This diversity in both parasite and vector populations indicates that complex malaria patterns are found in Papua New Guinea even at the moderate transmission levels found in low-lying inter-montane valleys.
Malaria
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upper case pea
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Papua New Guinea
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Study of epidemiology
;
Complex
8.Cannabis in Papua New Guinea.
Papua and New Guinea medical journal 2006;49(1-2):52-6
Cannabis is the most commonly used illicit drug in Papua New Guinea (PNG). Data on the epidemiology and history of cannabis in PNG are presented. The adverse health consequences of cannabis smoking and treatment options for cannabis dependence are discussed. It is recommended that a range of strategies are urgently required in PNG to prevent adverse physical and mental health consequences associated with cannabis smoking.
Cannabis
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Papua New Guinea
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Smoking
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Study of epidemiology
;
treatment options
9.The epidemiology of malaria in the Papua New Guinea highlands: 3. Simbu Province.
Ivo Mueller ; Julius Kundi ; Steve Bjorge ; Pioto Namuigi ; Gerard Saleu ; Ian D Riley ; John C Reeder
Papua and New Guinea medical journal 2004;47(3-4):159-73
Two very distinct malaria zones can be found within Simbu Province. The north of the province is characterized by the absence or very low level of local malaria transmission, but there is a considerable risk of epidemics prevalent in the lower-lying parts. During non-epidemic periods, parasite prevalence was usually under 5%, with similar frequencies for Plasmodium falciparum and P. vivax (47% each), and malaria was an only minor source of febrile illness. During epidemics, however, 13-36% of people were infected, predominantly with P. falciparum (64%), and high levels of severe morbidity were present. In south Simbu malaria is clearly endemic with an overall prevalence of 35%, combined with a strong age-dependence of infections, low haemoglobin levels, high rates of enlarged spleen and moderate to severe anaemia (haemoglobin level < 7.5 g/dl) in children. The malaria epidemiology in south Simbu is thus more similar to the lowlands than to other highlands areas. Epidemic prevention, surveillance and response in the north, and bednet distribution and strengthening of curative services in the south, are therefore the priorities for malaria control in Simbu Province.
Malaria
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Study of epidemiology
;
upper case pea
;
Prevalence aspects
;
epidemic aspects
10.The epidemiology of malaria in the Papua New Guinea highlands: 1. Western Highlands Province.
Ivo Mueller ; John Taime ; Rex Ivivi ; Simon Yala ; Steven Bjorge ; Ian D Riley ; John C Reeder
Papua and New Guinea medical journal 2003;46(1-2):16-31
Despite a resurgence of malaria in many Papua New Guinea highlands and highlands fringe areas after the cessation of control activities in the early 1980s the malaria situation in these areas has received little attention. A series of cross-sectional surveys were therefore carried out to provide accurate and up-to-date information on the prevalence of malaria and the risk of epidemics and to propose adequate malaria control strategies. Studies in 24 villages in Western Highlands Province found the prevalence of malarial infections to be strongly correlated with altitude, ranging from 1.6% at altitudes of 1500-1800 m to over 30% in villages below 900 m. Malaria outbreaks were observed at the end of the rainy season. All four human malaria species were present with P. falciparum infections clearly dominating. The relative importance of P. vivax increased with altitude, while both P. malariae and P. ovale were rare. Many infections were of low density. While malaria is an important source of febrile illness in endemic areas below 1500 m altitude, only few observed or reported fevers are due to malarial infections in higher, nonendemic areas. Rates of enlarged spleens, mean haemoglobin levels and the prevalence of anaemia (Hb <7.5 g/dl) were strongly linked to the level of malaria found in each community and were associated with both altitude and concurrent malarial infection. Based on the survey results, areas of different malaria epidemiology are delineated and options for control in each area are discussed.
Malaria
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upper case pea
;
Altitude
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Study of epidemiology
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Western Herbs and Botanicals