Development of the psychometric property of a Minimum Data-Set-Based Depression Rating Scale for use in long-term care facilities in Taiwan.

OBJECTIVES: Our aim is to develop the psychometric property of the Minimum Data-Set-Based Depression Rating Scale (MDS-DRS) to ensure its use to assess service needs and guide care plans for institutionalized residents. METHODS: 378 residents were recruited from the Haoran Senior Citizen Home in northern Taiwan. The MDS-DRS and GDS-SF were used to identify observable features of depression symptoms in the elderly residents. RESULTS: A total of 378 residents participated in this study. The receiver operating characteristic (ROC) curve indicated that the MDS-DRS has a 43.3% sensitivity and a 90.6% specificity when screening for depression symptoms. The total variance, explained by the two factors 'sadness' and 'distress,' was 58.1% based on the factor analysis. CONCLUSIONS: Reliable assessment tools for nurses are important because they allow the early detection of depression symptoms. The MDS-DRS items perform as well as the GDS-SF items in detecting depression symptoms. Furthermore, the MDS-DRS has the advantage of providing information to staff about care process implementation, which can facilitate the identification of areas that need improvement. Further research is needed to validate the use of the MDS-DRS in long-term care facilities.

The mediating effects of depressive symptoms on nutritional status of older adults in long-term care facilities.

OBJECTIVE: To test whether depressive symptoms mediate the effects of activities of daily living (ADLs) on nutritional status of older adults living in long-term care (LTC) facilities in Taiwan. DESIGN: A cross-sectional study. SETTING: Seventy-three community-based LTC facilities in northern Taiwan. PARTICIPANTS: This study sampled 306 adults ranging in age from 65 to 97 years who were free of acute infection or disease and who were able to communicate. MEASUREMENTS: Nutritional status was assessed by the Mini-Nutritional Assessment (MNA) scale and depressive symptoms were assessed by the short form of the Geriatric Depressive Scale (GDS-SF). RESULTS: MNA scores revealed that 65% of the subjects were at risk for malnutrition (17 to 23.5 points). In addition, depressive symptoms partially mediated the relationship between ADLs and nutritional status, with 10.7% of the effect of depressive symptoms on nutritional status going through the mediator. CONCLUSION: Interventions to reduce depressive symptoms among institutionalized older adults should focus on improving nutritional status rather than promoting ADLs, which are believed to be difficult to change.

Image segmentation by EM-based adaptive pulse coupled neural networks in brain magnetic resonance imaging.

We propose an automatic hybrid image segmentation model that integrates the statistical expectation maximization (EM) model and the spatial pulse coupled neural network (PCNN) for brain magnetic resonance imaging (MRI) segmentation. In addition, an adaptive mechanism is developed to fine tune the PCNN parameters. The EM model serves two functions: evaluation of the PCNN image segmentation and adaptive adjustment of the PCNN parameters for optimal segmentation. To evaluate the performance of the adaptive EM-PCNN, we use it to segment MR brain image into gray matter (GM), white matter (WM) and cerebrospinal fluid (CSF). The performance of the adaptive EM-PCNN is compared with that of the non-adaptive EM-PCNN, EM, and Bias Corrected Fuzzy C-Means (BCFCM) algorithms. The result is four sets of boundaries for the GM and the brain parenchyma (GM+WM), the two regions of most interest in medical research and clinical applications. Each set of boundaries is compared with the golden standard to evaluate the segmentation performance. The adaptive EM-PCNN significantly outperforms the non-adaptive EM-PCNN, EM, and BCFCM algorithms in gray mater segmentation. In brain parenchyma segmentation, the adaptive EM-PCNN significantly outperforms the BCFCM only. However, the adaptive EM-PCNN is better than the non-adaptive EM-PCNN and EM on average. We conclude that of the three approaches, the adaptive EM-PCNN yields the best results for gray matter and brain parenchyma segmentation.

Long-term care services needs for spinal-cord injury patients in Taiwan.

According to official health statistics, accidents and their adverse effects are the third leading cause of death in Taiwan. More accident victims are surviving thanks to treatment using high medical technology, but this results in many disabled patients with irreversible impairments. The demand for long-term care (LTC) services for spinal cord injury (SCI) patients has thus become a major concern. However, homebound SCI patients may easily face exclusion from LTC services because they are often ineligible for benefits under the regulations of National Health Insurance (NHI). The purposes of this study were: 1. To quantify the LTC needs of SCI patients, and 2. To evaluate the correlation between SCI patient health status and LTC needs. A total of 133 samples were visited from Kaohsiung City and Pingtung County. The results of this study showed that the average age of subjects was 43.15, with 72.9% male. The health status of most of the research subjects was fair (M = 2.33). The test of physiological health status was a 20-item scale with a five-point response format. The worst dysfunctions were urination (M = 3.36, SD = 1.06), sexual function (M = 3.30, SD = 0.88), excretion (M = 3.26, SD = 1.06), comfort (M = 3.25, SD = 0.84), and mobility (M = 2.75, SD = 1.11). All of the above items showed higher mean scores than average. More than one third of the subjects (36.8%) used wheelchairs, had better mobility and went out often. However, half of subjects were completely bedridden (45.9%). The mean psychosocial health status was poor with a mean score of 2.80 which showed higher mean score than average. The subjects were less satisfied with role function (M = 2.92), emotional stability (M = 2.92), and application for community resources (M = 2.79). The most needed LTC services for SCI patients was home-making services; referral and monitoring services ranked second. Suggestions derived from this study were to coordinate nursing care services with social support services for LTC patients and to allocate LTC resources based on patients' health status and their need for LTC services.

Occipital posterior and occipital transverse positions: reappraisal of the obstetric risks.

Malpositions in labour in a vertex-presenting fetus are known to be associated with increased risks of operative delivery A retrospective analysis of all deliveries over 4 years in a university teaching obstetric unit was performed using the available obstetric database. All cases of live births with cephalic presenting babies after 36 completed gestational weeks were analysed, and included 17,533 out of 20,533 total deliveries over the study period. The study group included those cases with occipital posterior and transverse positions, based on the documentation of the position of the vertex at the time of delivery, or at the last clinical examination before obstetric intervention, while occipital anterior cases constituted the control group. The overall incidence of malpositions was 14%, and operative delivery rate in the study group was 82.5% versus 20.7% in the control group. After excluding cases of operative delivery for non-mechanical indications, such as fetal distress, the adjusted odds ratio for the malposition group was 9.8 (95% CI 8.91-10.8) for total assisted delivery and 30.2 (95% CI 25.6-35.5) for Caesarean section compared to the occipital anterior group. Malpositions are definitely associated with a marked increase in the risk of operative delivery including Caesarean section. Labour complicated by malposition should be considered high risk, and should warrant due preparation for obstetric intervention.

Bartter's syndrome in pregnancy: a case report and review.

Bartter's syndrome is a rare renal tubular disorder, involving juxtaglomerular cells hyperplasia, characterized by normotensive hyper-reninism and secondary hyperaldosteronism, marked renal loss of potassium and profound hypokalaemia. Both clinical and biochemical features are heterogeneous, ranging from the incidental finding in an asymptomatic patient to marked clinical features of hypokalaemia. Inheritance is likely to be an autosomal recessive. We present a case of Bartter's syndrome complicating pregnancy in a Chinese woman. We documented an increasing demand for potassium supplement during pregnancy which stabilized by mid-trimester. The absence of pregnancy complications such as polyhydramnios indicated that the fetus was unlikely to be affected by the condition.

Thymidylate synthetase gene as a quantitative mutation marker in Chinese hamster cells.

A quantitative mutation marker for cultured mammalian cells is presented which uses a selective medium containing folinic acid, aminopterin and thymidine (the 'FAT' medium) to select for mutants deficient in thymidylate synthetase (TS) activity. Optimization of FAT medium was carried out using Chinese hamster V79 cell lines having 3 levels of TS activity. By manipulating the concentration of folinic acid in FAT medium, TS-deficient mutants can be readily selected. TS mutation is inducible in a dose-dependent manner by either ethyl methanesulfonate or ultraviolet light irradiation. Expression time for TS mutation was also determined using two concentrations of ethyl methanesulfonate and found to be very short, being 1 or 2 days. This newly characterized TS mutation marker should be useful in the study of both spontaneous and induced mutagenesis.

Single-step selection of mammalian cell mutants deficient in CTP synthetase.

A single-step selection of Chinese hamster V79 cells deficient in CTP synthetase (CTPS-) is presented. The underlying principle of the direct selection is the differential and efficient killing of synchronized wild-type cells through incorporation of [3H]uridine and [3H]thymidine. The CTPS- mutant cells were recovered by virtue of their not engaging in DNA synthesis, because (1) CTPS- cells are deficient in CTP synthetase and thus are unable to convert [3H]UTP into [3H]CTP, which eventually is converted into [3H]dCTP and incorporated into DNA; (2) the growth of CTPS- mutant cells was arrested as a result of cytidine deprivation, thus escaping the killing by the incorporation of [3H]thymidine. The isolated mutant clones are auxotrophic for cytidine and are stable in phenotype with a reversion frequency of less than 1 x 10(-7). The mutant cells have no or very low CTP synthetase activity when tested by in vitro CTP synthetase assay or by whole-cell [3H]uridine labeling assay. This modified "tritium suicide" method combined with the S-phase cell synchronization could provide a powerful means for the recovery from the cell population of nondividing mutant cells that are auxotrophic for some special nutrient requirement.

Evaluation of methods for the estimation of mutation rates in cultured mammalian cell populations.

A systematic comparison of 5 different statistical methods for the estimation of mutation rate (mu) in cultured Chinese hamster V79 cells is presented. Fluctuation tests were performed with several large batches of parallel cell cultures each allowed to grow for a different length of time in order to reach different population size (Nt). Based on Lea and Coulson's theoretical distribution, a comparison has been made between the experimental data and the expected distribution of the number of ouabain-resistant mutants per culture in these hamster cell populations. The sum of squared deviation between the observed and expected values, or SSD, was used as a means of the adequacy of the estimation method; the method which gives the smallest SSD is regarded as the best one for the estimation of mu. Our results show that when Nt is small, the occurrence of mutation is infrequent, and SSDs from different methods are similar. However, when Nt is large, there is a great discrepancy of the SSD values, suggesting a preference of using the maximum likelihood method, the Po method, the median method, the upper quartile method and the mean method, in that order, for the estimation of mu. The order of preference is correlated with estimation efficiencies. Depending on the size of Nt and the method used, the estimated mu may vary up to more than 3-fold. At a large Nt, the mu obtained from the maximum likelihood method is very precise. This suggests the importance of choosing an appropriate Nt as well as method for the estimation of mu.

A deterministic approach for the estimation of mutation rates in cultured mammalian cells.

Unequal growth rates between mutant and wild-type cells in a large population constitute a problem for the estimation of mutation rate. Over a period of cell growth, a selective advantage of one cell type over the other might lead to considerable error in the estimation of mutation rate if equal growth rates are assumed. In this study, we propose a formula and apply it to the estimation of spontaneous mutation rate in a growing population of Chinese hamster V79 cells in which ouabain-resistant mutant cells exhibit a slower growth rate than the wild-type cells. The formula is a generalization of that previously presented by Armitage (1953), and this is the first attempt to apply the deterministic approach for mutation rate estimation to cultured mammalian cells. The value of the estimated rate is compared with that derived from a parallel experiment using the fluctuation test of Luria and Delbrück (1943). The limitations and advantages of taking the deterministic approach to mutation rate estimation in mammalian cell systems are discussed.

Mutants of Chinese hamster cells deficient in thymidylate synthetase.

Stable mutants of Chinese hamster V79 cells deficient in thymidylate synthetase (TS; E.C. 2.1.1.45) have been selected from cultures grown in medium supplemented with folinic acid, aminopterin, and thymidine (FAT). After chemical mutagenesis, the frequency of colonies resistant to the "FAT" medium increased more than 100-fold over the spontaneous frequency. The optimal expression time of the mutant phenotype was 5-7 days after mutagen treatment. The recovery of FAT-resistant colonies in the selective medium was not affected by the presence of wild-type cells at a density below 9,000 cells per cm2. All 21 mutants tested exhibited thymidine auxotrophy; neither folinic acid nor deoxyuridine could support mutant cell growth. There was no detectable TS activity in all 11 mutants so far examined and only about 50% of wild-type activity in three prototrophic revertants, as measured by whole-cell and cell-free enzyme assays. The apparent Michaelis-Menten constant (Km) for deoxyuridine-5'-monophosphate and inhibition constant (Ki) for 5-fluoro-deoxyuridine-5'-monophosphate, measured by whole-cell enzyme assay, appear to be similar for the wild-type and revertant cell lines. Using 5-fluoro-[6-3H]-2'-deoxyuridine 5'-monophosphate as active site titrant, the relative amounts of TS in crude cell extract from the parental, revertant, and mutant cells were shown to exist in a 1:0.5:0 ratio. Furthermore, the enzymes from two revertants were more heat labile than that of V79 cells. These properties, taken together, suggest that the FAT-resistant, thymidine auxotrophic phenotype may be the result of a structural gene mutation at the TS locus. The availability of such a mutant facilitates studies on thymidylate stress in relation to DNA metabolism, cell growth, and mutagenesis.

Pleiotropic mutants of Chinese hamster cells with altered cytidine 5'-triphosphate synthetase.

Following chemical mutagenesis and multiple-step indirect selection, four clones of Chinese hamster V79 cells were isolated which exhibited auxotrophy for thymidine, deoxycytidine, or deoxyuridine but not for cytidine or uridine. All were resistant to uridine, 3-deazauridine, 5-fluorouridine, thymidine, and cytosine arabinoside at concentrations that were toxic to wild-type V79 cells. The cytidine 5'-triphosphate (CTP) and deoxycytidine 5'-triphosphate (dCTP) pools in the mutants were expanded, but the uridine 5'-triphosphate (UTP) pool either decreased or remained unchanged relative to the wild-type level. Furthermore, since the parental cells appear to be deficient in dCMP deaminase activity and CTP (or one of its metabolites) has been shown to inhibit uridine 5'-diphosphate (UDP) reduction, an elevated CTP level should lead to the observed thymidine auxotrophy. It also explains the joint resistance of mutant clones to thymidine and cytosine arabinoside. The change in the ratio of intracellular dCTP to thymidine 5'-triphosphate (dTTP) may be responsible for the elevation in the rates of spontaneous mutations in these mutants.

Estimation of mutation rates in cultured mammalian cells.

The factors that affect reliable estimations of mutation rates (mu) in cultured mammalian somatic cell populations by fluctuation analysis are studied experimentally and statistically. We analyze the differential effect of the final cell population size in each culture (Nt) and the number of parallel cultures (C) on the variation in the rate estimates (mu) inferred from the P0 method. The analysis can be made after the derivation of the variance of mu, which is a measure of variation of mu for a given combination of Nt and C in a number of repeat experiments. The variance of mu is inversely proportional to C and to the square of Nt . Nt determines the probability of occurrence of mutations in a cell culture. By influencing the size of P0, Nt also determines whether a rate estimate is obtainable from the experiment. Since Po is estimated from the fraction of cultures containing no mutation in a set of C cultures, C becomes a determining factor for the accuracy of mu. The rate estimated from P0 is biased, but the bias is in general 2 orders of magnitude smaller than mu. By the selection of an appropriate combination of Nt and C for the experiment, this bias can be reduced even further. Based on the notion of comparing two proportions, we propose a test statistic and have applied it to experimental results for a test of equality of mutation rates in different cell lines. This development places the comparison of mutation rates on a statistical basis.

Correlation between structural variation and activity of murine kidney beta-galactosidase: implications for genetic control.

Two closely linked regulatory genes have been reported to control activity levels of beta-galactosidases in murine tissues. The specific effects of these genes on murine glycolipid metabolism have not been elucidated. A/HeJ kidney 4-methylumbelliferyl-beta-galactosidase exhibited lower thermostability than the corresponding C57BL/6J and SWR/J enzymes. This altered response to heat segregated with the Bgsh allele among progeny derived from backcrosses of F1 (A/HeJ; SWR/J) mice to the respective parental strains. Restriction of the heat-sensitive A/HeJ beta-galactosidase to kidney tissue suggests that it is not determined by the Bgs locus, since the latter appears to be expressed in all tissues. More likely, the Bgs region of chromosome 9 contains a gene cluster consisting of a number of regulatory and structural loci. The proposed structural genes share affinity for the artificial substrates commonly employed for their assay but may differ in their relative affinities for glycosphingolipid substrates. Presence of the Bgsh allele results in an increase of kidney GM1-ganglioside-beta-galactosidase; however, galactosylceramide-beta-galactosidase appears unaffected by this allele.