Search PubMed⌕ Search

Biomedical subjects

P Weinstein

Publications and source records attributed to P Weinstein.

At least 37 records · Page 2Linked to original sources
PubMed2000

Dental caries and its relationship to bacterial infection, hypoplasia, diet, and oral hygiene in 6- to 36-month-old children.

UNLABELLED: Caufield et al. (1) have suggested that the acquisition of mutans streptococci in young children most likely takes place during a "window of infectivity" from 19 to 31 months of age. OBJECTIVES AND METHODS: This study determined the prevalence of dental caries and bacterial infection in a randomly selected sample of 199 children 6 to 36 months old from the island of Saipan in the Common-wealth of the Northern Mariana Islands, USA. The relationships between caries and Streptococcus mutans infection, hypoplasia, diet and oral hygiene behavior were investigated. RESULTS AND CONCLUSIONS: The overall estimated prevalence of caries was high: 46.8% of the children had white spot lesions and 39.1% had enamel cavitation. Colonization was seen in very young children; S. mutans was detected in 25% of the predentate children. The results of multi-variable modeling support the hypothesis that bacterial infection, diet, and hypoplasia are important in the etiology of dental caries in this population. Adjusted for age and ethnicity, children with a high level of S. mutans detected were 5 times more likely to have dental caries than children with a lower level of S. mutans detected. Hypoplasia and a high cariogenicity score (diet) were also significant independent predictors. The odds of having any white spot lesions or enamel cavitation were 9.6 times greater for children with any hypoplasia, and 7.8 times greater for children with high cariogenicity scores relative to those with lower scores after adjusting for level of S. mutans, age and ethnicity. Sleeping with a bottle, maternal sharing of utensils, and high snacking frequency were not significant predictors of caries in this population.

Analysis of Variance↗
PubMed2000

Coconut atrium: transmural calcification of the entire left atrium.

Massive calcification of the left atrium usually spares the interatrial septum, which provides a cleavage plane for surgical access to the mitral valve. Endoatriectomy with mitral valve replacement is the currently accepted corrective procedure because it affords maximum exposure while decreasing the risk of embolization and intraoperative hemorrhage. We describe a case in which the entire left atrium, including the septum, was thickly calcified and resembled a coconut shell. This condition prevented surgical correction of severe mitral stenosis. To our knowledge, this is the most severe case of left atrial calcification yet reported in the literature. Although it is not possible to establish preoperatively that the atrium is completely calcified and impossible to incise, when predisposing factors and evidence of complete transmural calcification are present, the surgeon should be aware of this possibility and should weigh carefully the decision to operate.

Aged↗
PubMed1999

Something in the water? A health impact assessment of disinfection by-products in New Zealand.

Disinfection by-products (DBP) are a large group of halogenated chemicals formed by the reaction of disinfectant agents with naturally-occurring organic substances in water. Numerous studies have found associations between DBP and some cancers and adverse reproductive outcomes. For both cancer and birth defects the relative risk associated with exposure to DBP is about 1.5. About 66% of New Zealanders, or 2.4 million people, use chlorinated water supplies and are exposed to DBP. New Zealand's unique combination of flora, climate and geology will create unique mixtures of DBP but little detailed information is available on the level or composition of DBP in New Zealand. The population attributable risk per cent, for cancers and birth defects in New Zealand, is about 25%. In other words, a quarter of all bladder, colon and rectal cancers and birth defects may be preventable by reducing DBP exposure. This is equal to 329 preventable cancer deaths in 1995 and 94 preventable birth defects in 1996. DBP exposure can be reduced without compromising microbiological safety of water supplies. The health effects of DBPs must be weighed against the cost of DBP reduction and not against the potential water borne disease prevented by disinfection. Some aspects of New Zealand's water supplies and population provide a unique opportunity to undertake research. Further research is needed on the occurrence of DBPs and their health consequences in order to undertake a properly informed risk assessment.

Abnormalities, Drug-Induced↗
PubMed1999

A randomized clinical trial of triazolam in 3- to 5-year-olds.

Triazolam has shown promise as a sedative agent for use in pediatric dentistry. However, the efficacy of triazolam has not been previously examined in a placebo-controlled study. The present clinical trial used a two-group, randomized, double-blind study design to compare the efficacy of oral triazolam with that of a placebo. The primary hypothesis tested was that triazolam would reduce negative behaviors of pediatric dental patients compared with a placebo. A secondary hypothesis was that triazolam would increase the efficiency of dental treatment by reducing the need for time-consuming behavior management by the pediatric dentist. The subjects were 54 3- to 5-year-old children, randomly assigned to the drug and placebo groups. The active drug, 0.03 mg/kg triazolam (Halcion), or lactose placebo was given orally 30 min before dental treatment. Behavior management techniques commonly used in pediatric dentistry were used during dental treatment. A single pediatric dentist provided all of the dental treatment. The procedure included an inferior block anesthesia and careful attention to anesthesia effectiveness. All sessions were video-taped and the tapes coded for child and dentist behaviors by an independent observer. There were no statistically significant differences between the groups with respect to completion of dental treatment. There were no significant differences found in either the total time or the percent of time that the subjects exhibited disruptive movements, verbal or non-verbal distress. The total use of time in the dental chair was slightly higher in the placebo than in the drug group due to more time spent preparing the child. Contrary to preliminary reports in the literature, this investigation found little or no improvement in child behavior when triazolam was used as a sedative compared with a placebo. However, triazolam did shorten the length of dental treatment, primarily by reducing dentist time in preparing the child for the dental procedure (e.g., establishing rapport and shaping behavior).

Administration, Oral↗
PubMed1999

El Niño and arboviral disease prediction.

Recent El Niño events have stimulated interest in the development of modeling techniques to forecast extremes of climate and related health events. Previous studies have documented associations between specific climate variables (particularly temperature and rainfall) and outbreaks of arboviral disease. In some countries, such diseases are sensitive to El Niño. Here we describe a climate-based model for the prediction of Ross River virus epidemics in Australia. From a literature search and data on case notifications, we determined in which years there were epidemics of Ross River virus in southern Australia between 1928 and 1998. Predictor variables were monthly Southern Oscillation index values for the year of an epidemic or lagged by 1 year. We found that in southeastern states, epidemic years were well predicted by monthly Southern Oscillation index values in January and September in the previous year. The model forecasts that there is a high probability of epidemic Ross River virus in the southern states of Australia in 1999. We conclude that epidemics of arboviral disease can, at least in principle, be predicted on the basis of climate relationships.

Arbovirus Infections↗
PubMed1999

El Niño and the dynamics of vectorborne disease transmission.

The objective of the study was to investigate the relationship between reported incidence of dengue fever and El Niño southern oscillation (ENSO) in 14 island nations of the South Pacific. Using a mixed ecological study design, we calculated correlations between annual averages of the southern oscillation index (SOI), local temperature and rainfall, and dengue fever. We also calculated temporal correlations between monthly reports of dengue fever cases on different islands. There were positive correlations between SOI and dengue in 10 countries. In five of these (including all of the larger islands) there were also positive correlations between SOI and estimates of local temperature and/or rainfall. There were temporal correlations between monthly reports of dengue cases within two groups of countries. Climate changes associated with ENSO may trigger an increase in dengue fever transmission in larger, more populated islands where the disease is endemic. There was also evidence of propagation of infection from larger islands to smaller neighbors. Unlike the initiation of epidemics, this transfer between islands appears to be independent of interannual climate variations, pointing to the importance of modulating factors in dengue transmission such as population density and travel. In the future, models of the impact of climate change must attempt to account for these factors.

Climate↗
PubMed1998

An explanatory model of the dental care utilization of low-income children.

OBJECTIVES: Factors related to the utilization of dental care by 5- to 11-year-old children from low-income households were investigated using a comprehensive multivariate model that assessed the contribution of structure, history, cognition, and expectations. The influence of dentist-patient interactions, psychosocial and health beliefs, particularly fear of the dentist, on utilization were investigated. METHODS: Children were chosen randomly from public schools, and 895 mothers were surveyed and their children were interviewed in the home. Utilization was studied during the 1991-1992 school year, including a 6-month follow-up period after the interview. RESULTS: The overall utilization rate was 63.2%, and the rate for nonemergent (preventive) visits was 59.9%. Utilization was unrelated to actual oral health status. Race and years the guardian lived in the United States were predictive of an episode of care. Preventive medical visits and perceived need were strong predictors of a visit to the dentist, as were beliefs in the efficacy of dental care. Mothers who were satisfied with their own care and oral health and whose children were covered by insurance were more likely to utilize children's dental care. In contrast, child dental fear and absences from school for family problems were associated with lower rates of utilization. CONCLUSIONS: Mutable factors that govern the use of care in this population were identified. These findings have implications for the design of dental care delivery systems for children and their families.

Adult↗
PubMed1998

Public health issues in early childhood caries.

Early childhood caries (ECC) is primarily a disease of poor, minority population children who generally have limited access to dental services. Public health dental clinics have not made the prevention and control of ECC a priority, and the services provided have not controlled ECC. New training and early screening are recommended. Additionally, repeated accessing of mothers and children through prenatal and postnatal medical visits is recommended. At such visits behavioral and chemotherapeutic strategies need to be utilized. Examples from a demonstration project in the Commonwealth of Northern Marianas are presented.

Cariostatic Agents↗
PubMed1998

Domestic Aedes aegypti breeding site surveillance: limitations of remote sensing as a predictive surveillance tool.

This project tested aerial photography as a surveillance tool in identifying residential premises at high risk of Aedes aegypti breeding by extending the use of a recently developed, ground-based, rapid assessment technique, the modified Premise Condition Index (PCI2). During 1995, we inspected 360 premises in Townsville, Australia for Ae. aegypti breeding, and PCI2 scores were recorded. The PCI2 values were also estimated from 1:3,000 color and infrared aerial photograph interpretation for the same premises. We found that shade levels can be accurately identified from both color and infrared images, and the PCI2 can be accurately identified from infrared photographs. Yard conditions, however, cannot be accurately identified from either aerial photograph type. The airborne PCI2 did not significantly correlate with breeding measures, and logistic regression further demonstrated that neither aerial photograph type allows the accurate prediction of Ae. aegypti breeding risk. Therefore, the ability of low-level aerial photography to enhance Ae. aegypti breeding site surveillance is at present limited, with ground surveillance remaining our most reliable tool for identifying the probability of Ae. aegypti breeding in the residential environment.

Aedes↗
PubMed1998

Dental fear among university students: implications for pharmacological research.

University students are often subjects in randomized clinical trials involving anxiolytic and analgesic medications used during clinical dental and medical procedures. The purpose of this study was to describe a typical university student population available for research by using data from a mail survey. Subjects were 350 students chosen randomly from all enrolled, full-time, traditional students on the main campus at the University of Washington in Seattle, WA. The aim was to determine the extent and nature of dental anxiety in this population. In addition, the relationships between subject willingness to receive dental injections and general and mental health and medical avoidance and medical fears were examined. The Dental Anxiety Scale (DAS) was used to measure dental anxiety. Dental anxiety was prevalent in this population; 19% of students reported high rates of dental fear. Thirteen percent of students had never had a dental injection. Students with no experience with dental injections were more reluctant than those with experience to receive an injection if one were needed. DAS scores were correlated with injection reluctance. Students who were reluctant to go ahead with a dental injection also reported poorer general and mental health than those who were less reluctant. These students also reported higher medical avoidance and medical anxiety scores. University students provide a rich source of potential subjects for clinical research. The student population, like the community at large, contains people with high levels of dental and medical fear.

Anesthesia, Dental↗
PubMed1998

Dental fear among university employees: implications for dental education.

We surveyed 350 University of Washington permanent employees chosen randomly from among both faculty and staff. The aim was to determine the extent and nature of dental anxiety in the university population potentially available for teaching clinics. In addition, the relationship of fears to self-reported dental health, utilization of dental care, and other general and mental health issues was examined. Dental anxiety was prevalent in this population; 13 percent of subjects reported high dental fear. In contrast to respondents with lower dental fear, subjects with clinically significant fear reported poorer perceived dental health, a longer interval since their last dental appointment, a higher frequency of past fear behaviors, more physical symptoms during last dental injection, and higher percentage of symptoms of anxiety and depression. Dental anxiety was not associated with poorer perceived general health or a longer interval since the last dental injection. University employees are a rich source of potential teaching patients for achieving curricular requirements for managing anxious patients. Student clinicians need guidance to be able to recognize fearful patients; they also need instruction about psychiatric conditions like anxiety and depression in order to be able to better manage and prevent dropouts in their patient roster.

Adult↗
PubMed1997

Pharmacokinetics of oral triazolam in children.

The purpose of this study was to determine the pharmacokinetic behavior of triazolam in children. Nine healthy children, aged 6 to 9 years, received oral triazolam (0.025 mg/kg suspended in Kool-Aid, Kraft General Foods, Chicago, IL) before dental treatment. Plasma triazolam concentrations were measured by gas chromatography/mass spectrophotometry at approximately 5, 15, 30, 45, 60, 90, 120, 180, and 240 minutes. A one-compartment model with first-order absorption and varying parameters was used, and estimated concentration curves were obtained for each subject. The observed peak plasma concentration was 8.5 +/- 3.0 ng/mL (mean +/- SD). The observed time to peak plasma concentration was 74 +/- 25 minutes. Elimination half-life was 213 +/- 144 minutes. Substantial recovery from signs and symptoms of clinical sedation required 180 to 240 minutes. The long duration of effect and relatively slow elimination should be noted by clinicians concerned with patient safety.

Biological Availability↗
PubMed1997

The Mount Ruapehu eruption, 1996: a review of potential health effects.

Literature search and consultation with New Zealand experts were used to review the potential health effects of explosive volcanic eruptions, and possibilities for their control, in the context of the 1996 eruption and possible future eruptions of Mount Ruapehu. Humans may be exposed to several types of hazardous ejecta during and after volcanic eruptions. Such exposure may cause health effects that could require surveillance and control, but health effects in New Zealand are unlikely to be detectable while eruptions remain small and infrequent. The existing health surveillance systems in New Zealand are adequate to monitor and help control the possible health effects of volcanic eruptions.

Environmental Monitoring↗
PubMed1997

An ecological approach to public health intervention: Ross River virus in Australia.

A detailed look at the ecology of a disease can lead to recommendations for public health interventions that are not otherwise obvious. To illustrate this point, this paper discusses the ecology and control of infection with the Australian arbovirus Ross River virus (RRV). The traditional insecticidal approach to mosquito control is recommended when an outbreak of RRV results from the expansion of an area endemic for the disease to include a population of previously unexposed (nonimmune) people. In contrast, if an outbreak results from the expansion of a non-immune population into an endemic area, an insecticidal approach can lead to an increased incidence of the disease. Education about antimosquito measures is more appropriate in the latter situation; the differing applicability of these intervention strategies is highlighted. Both strategies could be more scientifically applied if endemic areas were clearly defined by modeling ecological variables and if intervention were more closely linked to improved surveillance systems. An ecologically based control strategy must be developed for RRV to manage the disease appropriately when faced with its probable ecological changes brought about by global warming, increased rainfall, and demographic change. Key words: arbovirus, ecology, endemic, epidemic, global change, intervention.

Alphavirus Infections↗
PubMed1997

Four dimensions of fear of dental injections.

In 1995, students and staff at the University of Washington were surveyed regarding avoidance of dental care and fear of dental injections. More than 25 percent of adults surveyed expressed at least one clinically significant fear of injections. Almost one in 20 respondents indicated avoiding, cancelling or not appearing for dental appointments because of fear of dental injections. Fear of dental injections consists of four dimensions. General fear of dental injections including pain of injection and of bodily injury from injection are the two most common dimensions of dental injection fear. Many people also express fears of acquired disease. Fear related to local anesthetic (such as side effects, inadequate anesthesia) is less frequent. Some respondents have fears that must be categorized using more than one of these dimensions. Understanding the nature of a patient's fear of injection may suggest strategies to address his or her concerns.

Adolescent↗
PubMed1997

Subject recruitment, retention, and compliance in clinical trials in periodontics.

Recruitment of subjects in randomized controlled trials is the process of screening and enrolling a predetermined number of subjects within a planned time. Differences between projected and actual recruitment rates are common and, when large, form a serious threat to the successful completion of the trial. Recruitment can be enhanced by 1) use of different, concurrent recruitment methods; 2) avoiding underestimations of the costs and time intensity of subject recruitment; and 3) regular monitoring of the efficiency of the recruitment effort. The recruitment process can be complicated by legal requirements of proper representation of sex and race characteristics or by stringent entry criteria. Complex designs (e.g., trials with a pre-randomization placebo run-in, split-mouth designs) have not yet shown to be cost-effective and may endanger recruitment success. Enhancing both subject retention and protocol compliance requires careful planning, attention to product design and staff training. The impact on trial findings is discussed.

Humans↗