Abrasiveness of an air-powder polishing system on root surfaces in vitro.

OBJECTIVE: The purpose of this study was to evaluate the abrasiveness of a new air polisher on root surfaces. METHOD AND MATERIALS: Fifty extracted human teeth were air polished for 5 seconds. RESULTS: All root surfaces showed a circular defect visible with the naked eye. Scanning electron microscope examination showed smooth crater walls and a few open dentin tubules, but most seemed to be obliterated. Laser profilometry of the exposed areas revealed defects with an average depth of 484 microns, whereas the unexposed root surfaces showed irregularities with an average depth of 323 microns. The depths of the abraded areas were evaluated in relation to the values for the unexposed surfaces, and an average depth of 161 microns was found. The difference between the exposed and unexposed surfaces was statistically significant. CONCLUSION: The present study indicates that the air polisher has a strong abrading effect on exposed root surfaces and should therefore be used with caution on patients with gingival retractions.

Service use of rural and urban Medicaid beneficiaries suffering from depression: the role of supply.

Despite the prevalence and consequence of depression in rural areas, the literature on treating depression in rural areas is relatively scarce and inconclusive. The use of mental health services by rural people suffering from depression and the role that supply may play in explaining these differences are not well understood. Understanding these issues for rural Medicaid beneficiaries is important as Medicaid managed carefor physical and behavioral health care is expanded to rural areas. This study compares the mental health service use of rural and urban Medicaid beneficiaries, ages 18 to 64, in Maine suffering from depression and examines what influence mental health and primary care supply have in explaining observed differences. Two models are used to estimate the use of ambulatory mental health services: (1) a logit likelihood estimate of whether a beneficiary uses any outpatient mental health services for depression; (2) an ordinary least squares regression estimating the number of annualized ambulatory mental health care visits among users. Rural beneficiaries suffering from depression have lower utilization than urban beneficiaries. Rural and urban Aid for Families with Dependent Children (AFDC)--and Supplemental Security Income (SSI)--beneficiaries suffering from depression rely more on mental health than on general health care providers to receive ambulatory mental health care. Rural beneficiaries (AFDC and SSI) rely relatively more on general health care providers than urban beneficiaries. Multivariate analysis suggests that mental health supply and patient-level factors, but not primary care supply, account for utilization differences. This article describes the need to better understand factors limiting participation of primary care providers and to study the role of supply across multiple states.

Management of patients with depression by rural primary care practitioners.

OBJECTIVE: To investigate the extent to which variations in treatment and referral patterns for adult patients with diagnosed symptoms of depression seen in primary care practices are explained by practitioner characteristics, such as training, years in primary practice, sex, and knowledge about depression; practice characteristics, such as size, patient volume, and payer mix; and service area characteristics, such as availability of specialty mental health services and rural location. DESIGN: A 41-item telephone survey of primary care practitioners (PCPs) in Maine, including family and general practice doctors of medicine and doctors of osteopathy, general internists, nurse practitioners, and physician assistants (n = 267). MAIN OUTCOME MEASURE: The degree to which PCPs treat patients with depression themselves, rather than refer them to a mental health specialist. RESULTS: There is no significant (P = .10) urban-rural difference in the number of patients with depression seen as a percentage of total patient volume. Major barriers to referral to a mental health provider, as reported by the PCP, are long wait for an appointment, lack of available services, patients' unwillingness to use services, and reimbursement issues. Multivariate analyses indicate that PCP characteristics measuring knowledge and attitudes, as well as the lack of available services, are significantly related to treatment and referral patterns while practice characteristics and mental health provider supply are not. CONCLUSION: The treatment of rural patients with symptoms of depression is more likely to be improved by targeting PCPs' medical education than by efforts to increase the supply of specialty mental health providers in rural areas.

Access to physicians, obstetric care use, and adequacy of prenatal care for Medicaid patients in Maine: 1985-1989.

OBJECTIVE: To document trends in prenatal care utilization and provider participation in the Maine Medicaid program for the period 1985-1989, and to examine the effect of physician availability on adequacy of care. METHODS: Five years of Medicaid claims data and 3 years of claims data linked to birth certificates were analyzed. RESULTS: Large decreases in overall physician participation in the Medicaid program were due to reductions in the number of family physicians and general practitioners, whereas the number of obstetricians increased during this time. Large increases in provider caseloads resulted from an increase in recipient enrollment. The number of prenatal visits per patient, a measure of access, increased during this time. Adequacy of care was not associated with physician availability after controlling for maternal age, maternal education, out-migration for care, and type of location (rural versus urban). Important differences by type of location that emerged included less physician availability in rural areas but a higher likelihood of receiving adequate care. Women from low-availability areas were more likely to seek care outside of their primary care area of residence. Women living in rural areas who out-migrated for care were not more likely to receive inadequate prenatal care. CONCLUSION: Access to prenatal care for Medicaid recipients may have increased from 1985 to 1989 despite decreased overall physician participation in the program, perhaps because of more participating obstetricians. In addition, adequacy of care was not associated with physician availability in this population. Women residing in rural areas experienced lower physician availability and greater out-migration for care with no adverse effect on adequacy of prenatal care.

Determination of diethylcarbamazine, an antifilarial drug, in human urine by 1H-NMR spectroscopy.

1H-NMR spectroscopy is a convenient method for determination of diethylcarbamazine (DEC) in urine, and can be used to monitor medication with the drug. Urine samples were mixed with 10% of deuterium oxide as a spectrometer field frequency lock, which is the only sample pretreatment required. Tailored excitation with the 1331 pulse was used for water peak suppression. The quantification of DEC was carried out with the triplet of the N-ethyl group, for which the T1 relaxation time was 1 s. In aqueous solutions, amounts below 1 microgram ml-1 of DEC could be easily detected. In urine, the detectability depended on the level of chemical noise but was better than 10 micrograms ml-1. The accuracy and precision of the method were better than 15%. Analysis of urine from volunteers receiving a single therapeutic dose of DEC (6 mg kg-1 body weight orally) showed that the drug was eliminated in unchanged form during 2 days, in agreement with earlier results. The concentration of DEC in urine several hours after the intake exceeded 100 micrograms ml-1 making the 1H-NMR assay rapid and easy. No significant amounts of the N-oxide of DEC could be detected.

Access of rural AFDC Medicaid beneficiaries to mental health services.

This article examines geographic differences in the use of mental health services among Aid to Families with Dependent Children (AFDC)-eligible Medicaid beneficiaries in Maine. Findings indicate that rural AFDC beneficiaries have significantly lower utilization of mental health services than urban beneficiaries. Specialty mental health providers account for the majority of ambulatory visits for both rural and urban beneficiaries. However, rural beneficiaries rely more on primary-care providers than do urban beneficiaries. Differences in use are largely explained by variations in the supply of specialty mental health providers. This finding supports the long-held assumption that lower supply is a barrier to access to mental health services in rural areas.

The antibody response in serum, intestinal wall and intestinal lumen of NMRI mice infected with Echinostoma caproni.

Groups of mice (NMRI) were infected with 0, 6 and 25 metacercariae of the intestinal trematode Echinostoma caproni. An enzyme linked immunosorbent assay (ELISA) was developed for measuring the specific IgM, IgG and IgA antibody responses in serum, small intestinal tissue and small intestinal lumen of the mice, by using a crude adult E. caproni antigen. In infected mice, significant levels of IgM were measured in the sera from day 14 after infection and of IgG and IgA from day 28 after infection. Early in the infection, the mean level of serum IgM was higher in 6-worm infections than in 25-worm infections. Late in the infection, higher mean levels of IgA were reached in the serum of mice with high than in those with low dose infections. The onset of appearance of antibodies in the tissue of the small intestine reflected the picture seen in the serum. For IgM, and to a lesser degree for IgG, the highest mean antibody levels appeared in the posterior sections of the small intestinal wall, where also the parasites were located. The mean level of IgA, however, was uniform throughout the length of the small intestinal tissue. High levels of specific IgA were detected in the lumen of the small intestine on day 28 after infection, especially in the anterior sections, where only few parasites were located. No specific IgM or IgG could be detected in the intestinal lumen on this day. The results are related to the intestinal location and the pattern of expulsion of E. caproni in the mouse host.

Antibodies in the serum of golden hamsters experimentally infected with the intestinal trematode Echinostoma caproni.

The serum antibody response in golden hamsters (Mesocricetus auratus) infected with the intestinal trematode Echinostoma caproni was examined with ELISA, SDS-PAGE and Western blot, and IFAT techniques. All methods showed that the hamsters responded slowly but developed a clear positive humoral response to the infection. In most hamsters, an antibody response to infection could not be detected earlier than 11-13 weeks after infection with 6 or 25 metacercariae, and responses were weak when compared to previous results from mice infected with the same parasite. IFAT with positive hamster sera on live juvenile E. caproni showed only fluorescence at the posterior tip, which is a different pattern from that seen using from infected mice, indicating a different response to antigens on the juvenile parasites by these two hosts. The results are discussed in relation to the limited selfcure and development of resistance which is observed in golden hamsters infected with E. caproni.

A hydrophilic plasma polymerized film composite with potential application as an interface for biomaterials.

A hydrophilic polymer composite film (approx. 420 nm thick), with potential application as an interface for biomaterials has been prepared on nonorganic substrates, which include glass, silicon, and aluminum foil, using a glow discharge plasma polymerization technique. A thin film (110 nm thick) polymerized from hexane provided an adherent protective coating for the substrate material, and covalent bonding sites for the outer layer polymerized from N-vinyl-2-pyrrolidone. This outer layer provided the hydrophilic surface or interface. The two layers were copolymerized for a short period during transition between monomers to provide an intimate covalently bonded diffuse interphase. Preliminary in vitro and in vivo biocompatibility studies indicate that the hydrophilic film is non-cytotoxic, and does not increase the inflammatory response when compared with negative controls.

Cellular interactions with biomaterials: in vivo cracking of pre-stressed Pellethane 2363-80A.

The phenomenon of stress cracking of Pellethane 2363-80A (PEU) was investigated using the cage implant system. A cytotoxic polyvinylchloride (PVC) and a silicone rubber containing an anti-inflammatory steroid were used to create inflammatory environments in which the biostability of the pre-stressed PEU was tested. These coimplants provided alternative in vivo environments to study in vivo polymer interactions. The inflammatory responses to the implanted cages were monitored by analyzing the exudates aspirated from the cages at different implantation times over 21 days. The pre-stressed PEU specimens were retrieved after 5, 10, and 15 weeks postimplantation and examined by optical microscopy (OM) and scanning electron microscopy (SEM). The results support the conclusion that in vivo cracking of stressed (strained) Pellethane 80A is related to cell-polymer interactions. Severe cracking or rupture of the implanted PEU specimens was observed as early as 5 weeks postimplantation. Molecular chain degradation of the implanted specimens was evident from molecular weight measurements. Neither surface cracking nor degradation of macromolecules was found on the pre-stressed PEU specimens with the added cytotoxic PVC implanted over 15 weeks. No cracking was observed on the pre-stressed specimens in the presence of steroid silicone rubber, even after 10 weeks implantation.

Wilson's disease in Israel: a genetic and epidemiological study.

Clinical and family history data on persons affected with Wilson disease (WD) living in Israel between 1958 and 1984 were ascertained from the literature, hospital records and neurological and gastroenterological clinics. From this population of 51 families, representing a diversity of Middle Eastern. North African and European backgrounds, blood samples were collected from affected individuals in 21 families, their parents, sibs and other relatives for quantitative determinations of plasma copper and ceruloplasmin, liver tests and DNA analysis. Although the majority of patients have the hepatic form of the disease, hepatic and neurological cases were found among all ethnic groups. In fact, affected sibs in several inbred families who most likely inherited two copies of the same mutant allele had different symptoms. Gene frequencies were calculated for each of the populations taking into account inbreeding, probability of ascertainment, and estimated incidence. Although many of these communities have gene frequencies which are comparable to worldwide estimates, high prevalence of disease is maintained by consanguineous mating patterns. Probabilities of WND genotypes were calculated for 129 unaffected relatives who had an a priori risk of inheriting at least one WND allele using information from 10 DNA markers closely linked to the WND locus. There was no evidence that multiple loci are responsible for the observed clinical variability in this sample of families. Furthermore, studies of serum copper and ceruloplasmin levels in unaffected relatives suggest that phenotypic variability in WD may be due in part to an interaction of the WND locus with other genetic or non-genetic modifiers such as age.

Eight closely linked loci place the Wilson disease locus within 13q14-q21.

Wilson disease (WD) is an autosomal recessive disorder resulting in an accumulation of copper in the liver, brain, and other organs. The WD locus (WND) has previously been linked to esterase D (ESD) and localized to 13q14-22. With the large Centre d'Etude Polymorphisme Humain cohort, a refined map of DNA markers from this region was constructed, with the following locus order: D13S1-D13S21-D13S22-D13S10-ESD-RB-WND-D 13S26-D13S12-D13S2. A significant excess of male recombination was observed between D13S21 and D13S22. Intervals distal to D13S22 showed an excess of female recombination. When these markers were tested on 19 WD families from a variety of ethnic backgrounds, the two closest loci were shown to be RB and D13S26. The retinoblastoma gene locus (RB) was shown to be proximal to WND at a distance of 4.4 centimorgans (cM), and D13S26 was placed distal to WND at a distance of 4.0 cM. ESD was assigned proximally at a distance of 9.4 cM. In all families studied WND was linked to one or more of the loci ESD, RB, or D13S26.