Antibacterial silver-containing silica glass prepared by ion implantation.

Recently, there is much interest in nanocomposites consisting of metal nanoparticles dispersed in dielectric matrix. Silver is the first candidate used in antibacterial research. In the present study, sliver-containing silica glass is prepared by ion implantation. The bactericidal properties of Ag-implanted samples are investigated using E. coli. The implanted samples are characterized by optical absorption spectroscopy, atomic force microscopy and transmission electron microscopy. The size and position of the silver nanoparticles formed by ion implantation can be optimized by adjusting the implanted process parameters. All the implanted samples show antibacterial properties. But the samples with silver nanoparticle-enriched surfaces possess excellent antibacterial properties in comparison with other implanted samples. This indicates that ion implantation is a potential method for synthesizing antibacterial biomaterials.

The Prevalence of Frailty by the FRAIL-NH Scale in Taiwan Nursing Home Residents.

INTRODUCTION: The prevalence of frailty defined by FRAIL-NH varies among different studies in nursing homes, ranging from 19.0% to 75.6%. This study investigated the prevalence of frailty in a nursing home in Taiwan using different diagnostic criteria for frailty. METHODS: The 7-item FRAIL-NH scale was used for assessing frailty. There are 7 components: fatigue, resistance, mobility, incontinence or disease, weight loss, eating style and assistance with dressing. Each item is worth 0, 1, or 2 points for a total score of 14 points. We sorted and summarized the patients, according to the number of variables, into the not frail, frail, and most frail groups. Descriptive analysis was applied to understand the basic attributes of the elderly with different degrees of frailty, the influencing factors of frailty, and the occurrence of frailty. RESULTS: Our final sample included 34 residents. They were aged between 56 and 100 years (mean age 83.91 ± 10.84), and 18 (52.94%) were female. The frail group revealed a higher prevalence of males than of females. The marital status composition of participants was as follows: 2 (5.88%) unmarried, 24 (70.59%) married, and 8 (23.53%) widowed. The mean FRAIL-NH score was 5.79±3.72. CONCLUSIONS: A significant prevalence of frailty defined by FRAIL-NH was observed in a nursing home in Taiwan. Our findings indicate that frailty is an important issue in nursing homes. Further prospective cohort studies using FRAIL-NH evaluation are warranted.

Serum white blood cell count and pulmonary function test are negatively associated.

INTRODUCTION: A variety of inflammatory disorders influence the serum white blood cell (WBC) count. Elevated systemic inflammatory insult may contribute to impaired lung function, such as obstructive or restrictive lung disease. The aim of our study is to investigate the correlation between WBC count and pulmonary function. MATERIAL AND METHODS: Eligible participants aged ≥18 years (n=16 312) were enrolled from the United States National Health and Nutrition Examination Survey III, 1988-1994. Pertinent information including pulmonary function test, demographics, WBC count, glucose, C-reactive protein and a personal health questionnaire were obtained for subjects without known pulmonary diseases. White blood cell counts were classified into quartiles over the normal range. Multiple hierarchical regression models and trends testing were used to assess the correlation between WBC counts and pulmonary function tests. RESULTS: In the unadjusted mode of quartile-based analysis, the beta coefficients interpreted as the differences in FEV1% predicted upon comparing subjects in the upper three quartiles of WBC count to those in the lowest quartile were -0.007, -0.022 and -0.041 (P<0.001). After adjusting for multiple pertinent covariates, inverse association between quartiles of WBC count and FEV1% predicted remained essentially unchanged. The negative trends between FEV1% predicted and WBC count quartiles in the stratified comparison with extended-model approach were statistically significant (P for trends<0.001) in quartile-based multiple linear regression. CONCLUSIONS: Elevated WBC count is independently associated with declined pulmonary function. It may be a simple, accessible and inexpensive indicator of changes in pulmonary function.

Modulation of serum parathyroid hormone and ionized calcium concentrations during reproduction in rats fed a low calcium diet.

Moderate dietary restriction of calcium (0.1% Ca) was used to accentuate the changes in serum immunoreactive parathyroid hormone (iPTH) that had been reported earlier in lactating rats fed 0.4% Ca diet. In addition, the effects of this low-Ca diet on serum total and ionized Ca and iPTH during pregnancy, extended lactation, and weaning were examined. The positive correlation between serum total and ionized Ca was highly significant (r = 0.88, p less than 0.001, n = 120). Serum iPTH was significantly higher (36%) in pregnant rats on the day of parturition compared to nonmated controls, and there was a concomitant decrease in both total and ionized serum Ca. Within 1 day after parturition, however, serum Ca had risen to the control level. Serum iPTH remained significantly elevated during the first 2 weeks of lactation, and increased further during the third week of lactation to a level more than twice that of nonlactating controls. Serum Ca fell gradually during the second week of lactation. The high serum iPTH levels were maintained for another 2 weeks when lactation was extended with foster litters. Within 6 hr of removal of the suckling pups on day 16 of lactation, maternal serum ionized and total Ca had risen and serum iPTH had fallen; all three parameters were at levels similar to those of nonmated controls by 24-48 hr after weaning. The data suggest that serum ionized Ca is a major factor contributing to the hyperparathyroid state during lactation in rats fed a low-Ca diet.

Lower serum osteocalcin in ethanol-fed rats.

Serum osteocalcin was remarkably and significantly (-34 and -41% in two separate experiments; p less than 0.001) lower in rats fed an 8% (w/v) ethanol liquid diet (ELD) for 1 week than in rats fed an isocaloric control liquid diet (CLD). In a longer experiment that spanned 4 weeks, the ELD rats were given 6% ethanol on day 4, increased stepwise to 8% by day 9, and then maintained at 8% until day 28, when the experiment was terminated. Again, serum osteocalcin was much lower (-32%, p less than 0.001) in the ELD-fed rats than in CLD-fed rats. Even in rats fed only a 6% ELD for 12 days, serum osteocalcin was lower (-33%, p less than 0.001) than in controls. Also, the femora were weaker, more compliant, and more ductile in ELD-than in CLD-fed rats, findings that confirmed our earlier, related work. The fall in serum osteocalcin in ELD-fed rats is associated with a fall in femur ash weight and bone strength. There were significant correlations between serum osteocalcin and bone strength (r = 0.80; p less than 0.001) and between serum osteocalcin and bone stiffness (r = 0.83; p less than 0.001). Serum ionized calcium, like osteocalcin, was consistently lower in rats given ethanol for 1 or 4 weeks than in controls. From these experiments we conclude that excessive ethanol consumption inhibits osteoblastic activity as indicated by the reduced serum osteocalcin. The inhibition is also associated with other deleterious effects of ethanol on bone, including ash weight, bone strength, and bone stiffness.(ABSTRACT TRUNCATED AT 250 WORDS)

Cytochemical bioassay of circulating concentrations of rat parathyroid hormone: application to a study of age and sex.

We have found that the cytochemical bioassay (CBA) method, originally developed to measure circulating levels of biologically active parathyroid hormone (bioPTH) in humans, also can measure endogenous concentrations of PTH in rats. Therefore, we have applied this assay method to examine the relationships between age and sex and the circulating levels of bioPTH, calcium, and phosphorus in Fischer rats. The concentration of bioPTH increased in both males and females from 5 to 15 months of age (p less than .001) with no significant sex-related difference. Mean bioPTH values ranged from 2.3 to 3.6 pg (human PTH equivalents)/ml; these values were much lower (1 to 2 orders-of-magnitude) than those reported by others who used radioimmunoassays for PTH that do not discriminate between biologically active and inert PTH fragments. The CBA values for bioPTH were also 1/4-1/5 those obtained in rat serum by newer, more sensitive methods, the N-terminal specific PTH radioimmunoassay and the bioassay based on stimulation of chick renal adenylate cyclase. Regression analysis did not reveal any significant correlation between serum calcium and age. However, serum inorganic phosphorus decreased significantly (p less than .001) from 5 to 15 months of age in both male and female rats and was much lower in females than in males (p less than .001). The fall in serum phosphorus was negatively correlated with the rise in bioPTH (p less than .001). This study, the first to our knowledge to use a CBA to detect physiological changes in the circulating levels of bioPTH in rats, demonstrates the usefulness of the assay in experiments in this species.

Influence of lactation and pregnancy + lactation on mechanical properties and mineral content of the rat femur.

The quality of bone was assessed from femurs of rats both during lactation and after pregnancy + lactation. Mechanical properties of stiffness, strength, toughness, and ductility were measured, along with standard measurements of dry weight, ash weight, and total bone mineral. No changes occurred during the first week of lactation. During the second and third weeks of lactation all bone parameters except ductility decreased significantly. These data are consistent with bone losing mineral in order to supplement the dietary calcium intake necessary for milk production. In other experiments, femurs were collected from nulliparous rats and from rats that had previously undergone 1-3 pregnancy + lactations. The largest changes in bone mineral and mechanical properties occurred after a single pregnancy + lactation period, although significant further decreases in stiffness and strength occurred after the second pregnancy + lactation. No additional losses occurred following the third pregnancy + lactation. Even 5 months after only one pregnancy + lactation period, the bone quality was still impaired as all bone properties were lower than in nulliparous controls. Because the changes, especially stiffness and strength, were relatively larger than the changes in dry and ash weights of bone, measurements of these mechanical properties provide a more sensitive method to evaluate the quality of bone.

Increase in serum parathyroid hormone concentration in the lactating rat: effects of dietary calcium and lactational intensity.

The change in circulating levels of immunoreactive parathyroid hormone (iPTH), measured with an N-terminal specific radioimmunoassay, was examined during lactation in rats. In lactating rats consuming a diet containing 0.4% Ca (basic diet), serum iPTH was a) increased by an average of 53% between days 10 and 18 compared to the level of age-matched nonlactating rats (24.7 +/- 2.1 pg/ml vs 16.1 +/- 0.8 pg/ml, mean +/- SE, p less than 0.01) and b) significantly higher in dams suckling large litters (10-15 pups) than in dams suckling small litters (3 pups) over the period 3-13 days of lactation. Lactating rats consuming a low calcium diet (0.04% Ca), had serum iPTH levels on days 16-18 of lactation approximately twice those of nonlactating rats fed the same diet and 73% higher than those of lactating rats fed the basic diet. Serum Ca concentrations were 22% and 10% lower in dams consuming the 0.04 and 0.4% Ca diets, respectively, than in the nonlactating controls fed the same diets. Regression analysis showed a significant (p less than 0.001) negative correlation between iPTH and total serum calcium. Compared with nonmated controls, net mineral loss from femurs of dams consuming the 0.4% Ca diet was a) insignificant at day 6, b) 27% at day 15, and c) 34% at day 21 of lactation. Our data demonstrate that lactation in the rat is characterized by hyperparathyroidism that appears to be related to lactational intensity and that is accentuated when dietary calcium intake is restricted.(ABSTRACT TRUNCATED AT 250 WORDS)

Sex difference in serum calcitonin level in rats as related to feeding, fasting, and age.

Serum calcitonin (CT) was measured in male and female Fischer fasted and fed rats from 1-24 months of age. Previous findings by ourselves and others that serum CT rises with advancing age and is higher in females than in males were confirmed and extended. The effects of feeding were examined with the use of three different protocols, overnight fasting then feeding for 1 h, feeding ad libitum, and feeding rats for 2 h after they had been on a fixed feeding schedule for 4 weeks. At 1 month of age serum CT was too low to measure in either sex, fed or fasted. From 2-24 months of age, feeding increased serum immunoreactive CT much more in females than in males. The increase in serum CT was accompanied by a slight decrease in serum calcium. We concluded that the release of CT in rats after eating is sex related.

Hypercalcitoninemia associated with return of serum calcium concentration toward normal in chronically parathyroidectomized rats.

In chronically parathyroidectomized male Fischer and Holtzman rats, we found a progressive rise in the levels of serum immunoreactive calcitonin (CT) despite hypocalcemia. The rise was preceded by an increase in the thyroidal CT concentration (determined by RIA) and hyperplasia of C cells (determined by the immunoperoxidase bridge technique). In association with the rise in serum CT, we also observed a return of serum Ca toward normal levels, which the evidence suggests was not due to compensatory regeneration of parathyroid remnants after incomplete parathyroidectomy. It also is unlikely that ectopic parathyroid tissue was responsible for the return of serum Ca toward normal. Since the increase in serum CT after parathyroidectomy coincided with the return of serum Ca toward normal, we postulate that a gradual rise in serum Ca in chronically parathyroidectomized rats might stimulate the "CT-saturated" thyroid glands to release CT, thus leading to a progressive increase in serum CT. Alternatively, it is possible that the increase in serum CT after parathyroidectomy may be due in part simply to nonspecific leakage of CT from the "CT-saturated" thyroid glands.

Identification of C-cells in normal and goitrous rat thyroid tissues using antiserum to rat thyrocalcitonin and the immunoperoxidase bridge technique.

Application of the immunoperoxidase bridge technique to the light microscopic localization of C-cells in rat thyroid tissue is described. Guinea pig antisera to rat thyrocalcitonin (TCT) were produced by the injection of highly purified rat TCT (100-300 MRC U/mg) emulsified in complete Freund's adjuvant. A 1:1000 dilution of the antiserum used in this study gave a strong positive reaction with rat C-cells, and 1 ml of undiluted antiserum provided sufficient material for staining approximately 5000 slides. The substitution of nonimmune guinea pig serum for the anti-rat TCT serum or the prior absorption of anti-rat TCT serum with increasing amounts of highly purified rat TCT both eliminated the staining of thyroid C-cells. Likewise, no staining was observed in tissue sections from rat parathyroid, ovary, pituitary gland, and skeletal muscle. Antiserum to synthetic human TCT also could be used to identify rat thyroid C-cells. The method revealed abundant C-cells in goiters from rats fed a low-iodine diet for more than 1 year. This finding was supported by electron microscopic evaluation of goitrous tissue and by the detection, by radioimmunoassay, of TCT in thyroid tissue and in peripheral blood from goitrous rats.

Calcitonin-like immunoreactivity in rat and human pituitary glands: histochemical, in vitro, and in vivo studies.

This study was designed to determine whether pituitary glands contain an immunoreactive material which reacts with antisera to calcitonin (CT) and, if so, whether secretion of the material could be demonstrated. Testing 15 antisera to rat and human CT and using an immunoperoxidase method, we found 2 antisera to human CT which stained rat pituitaries and several which stained human pituitaries. Essentially all cells in the rat intermediate lobe and scattered cells in the rat and human anterior lobes showed staining, and staining was not entirely abolished by prior adsorption of antisera with rat or human CT. The 2 antisera which stained rat pituitaries showed cross-reactivity with several synthetic human CT fragments (1-18, 11-23 and 22-32) but not with ACTH-(1-39), ACTH-(1-24), beta-endorphin, alpha- or beta MSH, or bovine lipotropin. Crude extracts of pituitaries from 2 strains of young rats showed CT-like immunoreactivity which could be measured easily by RIA (0.2-0.3 ng/gland). In vivo, an antiserum which stained pituitaries and 1 which did not were compared using young rats made hypercalcemic (15-20 mg/dl) with iv Ca. In rats with thyroids, both antisera showed an increase in serum CT of more than 15-fold whether the pituitary was present or absent. In thyroidectomized rats, serum CT remained undetectable (less than 50 to 100 pg/ml) during hypercalcemia even if the pituitary was present. In vitro, rat pituitaries in a serum-free medium did not release measurable amounts of immunoreactive CT-like material even when medium contained high Ca (2.5 mM), high K (25 mM), or TRH (10(-6) M). Therefore, the findings agree with other reports of a CT-like material in the pituitary, but no secretion of the material could be demonstrated. We hypothesize that the material is not authentic CT but is, rather a related peptide sequence probably contained in the 31 K precursor protein of ACTH-beta-lipotropin.

C-cell nodules in adult human thyroid. A common autopsy finding.

This study was designed to examine the morphologic features and distribution of calcitonin-producing cells (C-cells) in normal adults and in a general autopsy population. Random or serial sections from thyroid glands in forensic and general autopsies were examined by an immunoperoxidase stain for calcitonin to identify C-cells. Six glands out of 30 cases contained large C-cell nodules (85-343 C-cell nuclei per nodule). Five of the nodules were in patients over 50 years of age. C-cell nodules in thyroid sections may represent age-related hyperplasia or a normal variation of ontogeny. This study underscores the importance of serially sectioning the thyroid to evaluate nodular C-cell hyperplasia in preneoplastic or nonneoplastic functional disorders.

Serum calcitonin, calcium and thyroxine in young and old Zucker fatty rats (fa/fa).

We determined the serum levels of calcitonin (CT), calcium (Ca), and thyroxine (Ti) in lean (?/+) and fatty (fa/fa) male Zucker rats 10 weeks and 10-12 months of age. The most dramatic finding was a high level of serum CT (3.24 +/- 1.18 ng/ml) in young fatties whereas sera from young leans were all below the limit of assay detection (less than 0.120 ng/ml, p less than 0.01). Young fat rats also had elevated levels of both Ca (11.2 +/- 0.2 vs. 9.7 +/- 0.2 mg/dl, p less than 0.001) and Ti (6.7 +/- 0.48 vs. 4.72 +/- 0.28 micrograms/dl, p less than 0.01). In older animals the mean serum level of CT increased further in the fatties and became readily measurable in leans (5.67 +/- 1.94 vs. 1.49 +/- 0.55, p less than 0.01). Thyroid C-cells, identified immunohistochemically, were abundant in both leans and fatties at this age but were substantially more numerous in the fat rats (p less than 0.001). Calcium levels increased somewhat in the older leans, but still remained higher in the fat rats (p less than 0.05). Thyroxine values were essentially the same for old animals of both genotypes (5.07 +/- 0.61 vs. 5.54 +/- 0.88). Age effects were not significant for any measure in the fat animals, but in the leans there were significant age-related increases in CT (p less than 0.02) and serum Ca (p less than 0.05).

Peripartum cardiomyopathy--a case report.

Peripartum cardiomyopathy in the form of congestive heart disease of unknown etiology appears relatively rarely during the last month of pregnancy or within 5 months after delivery, and it is potentially life-threatening. This case report describes a 34-year-old female, G4P1, at 36 weeks' gestation who was admitted for cesarean section under lumbar epidural anesthesia due to twin pregnancy. She had no past history of cardiovascular diseases. However, rapid onset of dyspnea at ward and acute cardiac failure developed 15 h after cesarean section. Peripartum cardiomyopathy was diagnosed. After a 7-day intensive treatment she was discharged. Since then she was symptom-free and her two babies were doing well during a period of one more years after discharge.

Epidural anesthesia for emergency caesarean section in a patient with single ventricle and aortic stenosis.

A 24-year-old parturient with single ventricle and moderate aortic stenosis was admitted due to preeclampsia and fetal distress at 31 weeks' gestation. Emergency Caesarean section was performed under lumbar epidural anesthesia and epidural analgesia was given for post-operative pain control. Mother and baby both survived. The anesthetic techniques and managements in other parturients with similar congenital cardiac anomalies are also reviewed and described.

Synthesis and Magnetic Properties of Maghemite (gamma-Fe(2)O(3)) Short-Nanotubes.

We report a rational synthesis of maghemite (gamma-Fe(2)O(3)) short-nanotubes (SNTs) by a convenient hydrothermal method and subsequent annealing process. The structure, shape, and magnetic properties of the SNTs were investigated. Room-temperature and low-temperature magnetic measurements show that the as-fabricated gamma-Fe(2)O(3) SNTs are ferromagnetic, and its coercivity is nonzero when the temperature above blocking temperature (T(B)). The hysteresis loop was operated to show that the magnetic properties of gamma-Fe(2)O(3) SNTs are strongly influenced by the morphology of the crystal. The unique magnetic behaviors were interpreted by the competition of the demagnetization energy of quasi-one-dimensional nanostructures and the magnetocrystalline anisotropy energy of particles in SNTs.