Localized Nanoresonator Mode in Plasmonic Microcavities.

Submicron-thick hexagonal boron nitride crystals embedded in noble metals form planar Fabry-Perot half-microcavities. Depositing Au nanoparticles on top of these microcavities forms previously unidentified angle- and polarization-sensitive nanoresonator modes that are tightly laterally confined by the nanoparticle. Comparing dark-field scattering with reflection spectroscopies shows plasmonic and Fabry-Perot-like enhancements magnify subtle interference contributions, which lead to unexpected redshifts in the dark-field spectra, explained by the presence of these new modes.

Relative weight at ages 10 and 16 years and risk of endometriosis: a case-control analysis.

BACKGROUND: Although previous epidemiological studies have shown that women with endometriosis are more likely to be thinner and underweight, it is currently not clear whether this is a true characteristic of women who develop endometriosis or a consequence of their disease and its symptoms. The aim of this study was to investigate the relationship between endometriosis and relative weight in childhood and adolescence, prior to diagnosis. METHODS: This case-control study included 268 Australian women with surgically confirmed moderate to severe endometriosis (cases) and 244 women without endometriosis (controls). Relative weight at ages 10 and 16 years, as recalled and classified ('underweight', 'average weight' and 'overweight') separately by the women themselves and their mothers, was analyzed. RESULTS: Women who reported being overweight at 10 years had an increased risk of endometriosis (OR 2.8; 95% CI 1.1-7.5). Mothers' reports and concordant responses among mother-daughter pairs were consistent with this association. There was no clear evidence of an association between relative weight at 16 years and risk of endometriosis. CONCLUSIONS: These data suggest that being overweight during late childhood is associated with the development of endometriosis; however, the results warrant confirmation in larger study populations.

Bacterioplankton: a sink for carbon in a coastal marine plankton community.

Recent determinations of high production rates (up to 30 percent of primary production in surface waters) implicate free-living marine bacterioplankton as a link in a "microbial loop" that supplements phytoplankton as food for herbivores. An enclosed water column of 300 cubic meters was used to test the microbial loop hypothesis by following the fate of carbon-14-labeled bacterioplankton for over 50 days. Only 2 percent of the label initially fixed from carbon-14-labeled glucose by bacteria was present in larger organisms after 13 days, at which time about 20 percent of the total label added remained in the particulate fraction. Most of the label appeared to pass directly from particles smaller than 1 micrometer (heterotrophic bacterioplankton and some bacteriovores) to respired labeled carbon dioxide or to regenerated dissolved organic carbon-14. Secondary (and, by implication, primary) production by organisms smaller than 1 micrometer may not be an important food source in marine food chains. Bacterioplankton can be a sink for carbon in planktonic food webs and may serve principally as agents of nutrient regeneration rather than as food.

Ten-year outcomes following traumatic brain injury: a population-based cohort.

PRIMARY OBJECTIVE: To quantify the 10 year health service use (HSU) and mortality outcomes for people with a traumatic brain injury (TBI). RESEARCH DESIGN: A population-based matched cohort study using linked administrative data from Manitoba, Canada (Manitoba Injury Outcome Study). METHODS AND PROCEDURES: An inception cohort (1988-1991) of hospitalized cases with TBI aged 18-64 years (n = 1290) was identified and matched to a non-injured comparison group (n = 1290). Survival analysis, Negative binomial and Poisson regression were used to quantify associations between injury and HSU/mortality outcomes for 10 years following the TBI event. MAIN OUTCOME AND RESULTS: The majority of deaths (47.2%) occurred in the first 60 days following injury. Excluding the first 60 days, the adjusted 10 year mortality remained elevated (mortality rate ratio = 1.48, 95% CI = 1.02-2.15). After adjusting for demographic characteristics and pre-existing health status, the TBI cohort had more post-injury hospitalizations (rate ratio (RR) = 1.54, 95% CI = 1.39-1.71), greater cumulative lengths of stay (RR = 5.14, 95% CI = 3.29-8.02) and a greater post-injury physician claims rate (RR = 1.44, 95% CI = 1.35-1.53) than the non-injured cohort. CONCLUSIONS: People who sustain a TBI and survive the initial acute phase of care experience substantially increased long-term morbidity compared to the general population, regardless of the level of injury severity.

Cleaning interfaces in layered materials heterostructures.

Heterostructures formed by stacking layered materials require atomically clean interfaces. However, contaminants are usually trapped between the layers, aggregating into randomly located blisters, incompatible with scalable fabrication processes. Here we report a process to remove blisters from fully formed heterostructures. Our method is over an order of magnitude faster than those previously reported and allows multiple interfaces to be cleaned simultaneously. We fabricate blister-free regions of graphene encapsulated in hexagonal boron nitride with an area ~ 5000 µm2, achieving mobilities up to 180,000 cm2 V-1 s-1 at room temperature, and 1.8 × 106 cm2 V-1 s-1 at 9 K. We also assemble heterostructures using graphene intentionally exposed to polymers and solvents. After cleaning, these samples reach similar mobilities. This demonstrates that exposure of graphene to process-related contaminants is compatible with the realization of high mobility samples, paving the way to the development of wafer-scale processes for the integration of layered materials in (opto)electronic devices.

Long-term mortality following injury in working-age adults: a systematic review.

Priorities for prevention activities and planning for services depend on comprehensive knowledge of the distribution of the injury-related burden in the community. The aim of this systematic review was to quantify the effect of being injured, compared with not being injured, on long-term mortality in working age adults. Cohort studies were selected that were population-based, measured mortality post-discharge from inpatient treatment, included a non-injured comparison group and related to working-age adults. Data synthesis was in tabular and text form with a meta-analysis not being possible because of the heterogeneity between studies. Eleven studies met the inclusion criteria. All studies found an overall positive association between injury and increased mortality. While the greatest excess mortality was evident during the initial period post-injury, increased mortality was shown in some studies to persist for up to 40 years after injury. Due to the limited number of injury types studied and heterogeneity between studies, there is insufficient published evidence on which to calculate population estimates of long-term mortality, where injury is a component cause. The review does suggest there is considerable excess mortality following injury that is not accounted for in current methods of quantifying injury burden, and is not used to assess quality and effectiveness of trauma care.

Long term health outcomes after injury in working age adults: a systematic review.

BACKGROUND: Estimating the contribution of non-fatal injury outcomes remains a considerable challenge and is one of the most difficult components of burden of disease analysis. The aim of this systematic review was to quantify the effect of being injured compared with not being injured on morbidity and health service use (HSU) in working age adults. METHODS: Studies were selected that were population based, had long term health outcomes measured, included a non-injured comparison group, and related to working age adults. Meta-analysis was not attempted because of the heterogeneity between studies. RESULTS: Nine studies met the inclusion criteria. In general, studies found an overall positive association between injury and increased HSU, exceeding that of the general population, which in some studies persisted for up to 50 years after injury. Disease outcome studies after injury were less consistent, with null findings reported. CONCLUSION: Because of the limited injury types studied and heterogeneity between study outcome measures and follow up, there is insufficient published evidence on which to calculate population estimates of long term morbidity, where injury is a component cause. However, the review does suggest injured people have an increased risk of long term HSU that is not accounted for in current methods of quantifying injury burden.

A combination of genetic polymorphisms increases the risk of progressive disease in chronic hepatitis C.

BACKGROUND: There is increasing interest in the influence of host genetic factors on hepatic fibrosis, and whether genetic markers can reliably identify subjects at risk of developing severe disease. We hypothesised that hepatitis C virus (HCV) infected subjects with progressive fibrosis, classified using strict criteria based on histology at biopsy in addition to disease duration would be more likely to inherit several genetic polymorphisms associated with disease progression compared with subjects with a low rate of disease progression. METHODS: We examined polymorphisms in eight genes that have been reported to have an association with hepatic fibrosis. RESULTS: Associations between polymorphisms in six genes and more rapidly progressing fibrosis were observed, with individual adjusted odds ratios ranging from 2.1 to 4.5. The relationship between rapidly progressing fibrosis and possession of > or =3, > or =4, or > or =5 progression associated alleles was determined and the adjusted odds ratios increased with increasing number of progression associated alleles (9.1, 15.5, and 24.1, respectively). Using logistic regression analysis, a predictive equation was developed and tested using a second cohort of patients with rapidly progressing fibrosis. The predictive equation correctly classified 80% of patients in this second cohort. CONCLUSIONS: This approach may allow determination of a genetic profile predictive of rapid disease progression in HCV and identify patients warranting more aggressive therapeutic management.

Relationship between number of ovulatory cycles and accumulation of mutant p53 in epithelial ovarian cancer.

BACKGROUND: It has been suggested that increased numbers of ovulations might increase the risk of p53 gene (also known as TP53) mutation in the ovarian epithelium, thereby leading to the development of cancer. The data supporting this hypothesis have come from an observation that accumulation of p53 protein in epithelial ovarian cancer was strongly associated with increasing numbers of ovulatory cycles. We have further investigated the association between ovulatory history and p53 gene mutation by use of data from a large case-control study of ovarian cancer in Australia. METHODS: Tissue blocks were available for immunohistochemical analysis of p53 protein from 234 case subjects, aged 18-79 years, who had invasive epithelial ovarian cancer. Epidemiologic data were also available for these women and for 855 control subjects. Case-case comparisons were made by use of prevalence ratios and 95% confidence intervals (CIs), and case-control comparisons were made by use of odds ratios (ORs) and 95% CIs. All statistical tests were two-sided. RESULTS: There was no association between p53 accumulation and years of ovulation. Women with p53-positive cancers had undergone an average of 29.3 years of ovulation compared with 29.0 years of ovulation for women with p53-negative cancers (P=.8). Although the overall risk of ovarian cancer development was significantly increased in women who had undergone more years of ovulation (OR=2.17; 95% CI =1.54-3.05-for > or =35 years versus <23 years of ovulation), there was no difference in the risk associated with p53-positive and p53-negative cancers. CONCLUSIONS: These results confirm the association between increased ovulation and ovarian cancer risk but do not support the hypothesis that this association is due to an increased risk of p53 mutation with a greater number of ovulatory cycles.

Multiple births and risk of epithelial ovarian cancer.

BACKGROUND AND METHODS: Prevailing hypotheses about the causes of ovarian carcinogenesis predict that women with a history of multiple births (twins, triplets, etc.) should be at increased risk of epithelial ovarian cancer. However, the scant available evidence suggests that they may actually be at lower risk. To resolve this issue, we pooled data from eight studies involving 2859 parous women with epithelial ovarian cancer (case patients) and 7434 parous women without ovarian cancer (control women). In addition to assessing their history of multiple births (and the sex of the children, where available), we obtained information on age, parity, oral contraceptive use, and other reproductive factors for each woman. Details of tumor histology were available for all case patients. We estimated the relative risks of various histologic types of ovarian cancers associated with multiple births by using multivariable logistic regression analysis, adjusting for matching and confounding variables. RESULTS: Among these parous women, 73 case patients (2. 6%) and 257 control women (3.5%) had a history of multiple births. The adjusted summary odds ratio (OR) for developing all types of epithelial ovarian cancer that are associated with multiple births was 0.81 (95% confidence interval [CI] = 0.61-1.08). We found no evidence that risks associated with multiple births differed among women with borderline or invasive tumors and among women with same-sex and opposite-sex offspring from multiple births. The risk reductions appeared specific for nonmucinous tumors (n = 2453; summary adjusted OR = 0.71 [95% CI = 0.52-0.98]); in contrast, associations with mucinous tumors (n = 406) were heterogeneous across studies. CONCLUSIONS: Parous women with nonmucinous ovarian cancer are no more likely to have a history of multiple births than other parous women, counter to the predictions of current hypotheses for causes of ovarian cancer.

Proliferation, apoptosis, and survival in high-level microsatellite instability sporadic colorectal cancer.

Sporadic colorectal cancer (CRC) characterized by high-level DNA microsatellite instability (MSI-H) has a favorable prognosis. The reason for this MSI-H survival advantage is not known. The aim of this study was to correlate proliferation, apoptosis, and prognosis in CRC stratified by MSI status. The proliferative index (PI) was measured by immunohistochemical staining with the Ki-67 antibody in a selected series of 100 sporadic colorectal cancers classified according to the level of MSI as 31 MSI-H, 29 MSI-Low (MSI-L), and 40 microsatellite stable (MSS). The Ki-67 index was significantly higher in MSI-H cancers (P < 0.0001) in which the PI was 90.1 +/- 1.2% (mean +/- SE) compared with 69.5 +/- 3.1% and 69.5 +/- 2.3% in MSI-L and MSS subgroups, respectively. There was a positive linear correlation between the apoptotic index (AI) and PI (r = 0.51; P < 0.001), with MSI-H cancers demonstrating an increased AI:PI ratio indicative of a lower index of cell production. A high PI showed a trend toward predicting improved survival within MSI-H cancers (P = 0.09) but did not predict survival in MSI-L or MSS cancers. The AI was not associated with survival in any MSI subgroup. In conclusion, this is the first study to show that sporadic MSI-H cancers are characterized by a higher AI:PI ratio and increased proliferative activity compared with MSI-L and MSS cancers, and that an elevated PI may confer a survival advantage within the MSI-H subset.

Indicators of injury burden: which types are the most important?

Injury indicators are used for monitoring the impact of injury prevention initiatives on the population burden of injury. The object of the present study was to identify the types of injury responsible for the major component of the population health burden of injury in a large cohort in Manitoba, Canada. Injury cases (ICD-9-CM 800-995) aged 18-64 years were identified from all Manitoba hospital data between 1988 and 1991. Morbidity data were obtained from hospital discharge abstracts 12 months prior to date of injury and for 12 months post-injury. Outcomes for individuals were calculated as the difference pre- and post-injury in hospital inpatient days. Death outcomes in the 12 months post-injury were obtained by linking the cohort with the population registry. Summed outcomes across the population were stratified into injury types based on the International Code of Diseases (ICD) code of the index injury. Outcomes were also stratified by injury severity score categories where the injury severity score was obtained using ICDMAP-90. When ranked by contribution to the cohort's cumulative hospital inpatient days in the 12 months post-injury, the six most common ICD subchapter groups accounted for 65% of the total inpatient days. These six injury types also accounted for 62% of the total number of deaths in this cohort in 12 months after injury. The suggested injury types to use as indicators of burden include fracture of the lower limb, fracture of the head and neck, poisonings, intracranial injury, fracture of the upper limb, and fracture of skull.

How well do anatomical-based injury severity scores predict health service use in the 12 months after injury?

There is an acknowledged need for valid and reliable injury scores, suitable for use at the population level, which can accurately predict the long-term outcome of injury. The objective was to quantify the extent to which the abbreviated injury severity score (AIS) and the functional capacity index score (FCI) predict use of health services in the 12 months following an injury event. A cohort of injured people (ICD-9-CM 800-995) aged 18 - 64 years was identified from Manitoba hospital discharge abstracts from January 1988 to December 1991. For each member of the cohort whose injuries could be mapped to an abbreviated injury scale unique identifier, a maximum AIS (maxAIS) and a maximum FCI (maxFCI) were obtained. The cohort was linked with hospital discharge abstracts, physicians' claims and deaths from the population registry for the 12 months following injury. Negative binomial regression was used to model the relationships between the severity scores and the three outcome measures, while controlling for potential confounding variables. In total, 20 677 (97%) eligible cases were identified, of which 16 834 (81%) could be assigned a maxAIS and 15 823 (77%) a maxFCI. MaxAIS and maxFCI were significantly associated with total days in hospital following injury, but explained little of the variation in any of the health service use outcome variables (maxAIS, partial pseudo r2 ranging from < 0.001 to 0.041; and maxFCI, partial pseudo r2 ranging from < 0.001 to 0.018). It was concluded that anatomical damage is only partly responsible for long-term injury outcome. Additional variables would need to be included in predictive models of health outcomes of injury before these models could be reliable.

The steroid 5alpha-reductase type II TA repeat polymorphism is not associated with risk of breast or ovarian cancer in Australian women.

The enzyme 5alpha-reductase type II (SRD5A2) converts testosterone to its more active form 5alpha-dihydroxytestosterone. The 3' untranslated region of the gene contains a (TA)(n) length polymorphism. The (TA)(9) allele has been reported to be associated with higher serum prostate-specific antigen levels in breast tumors and lower risk of relapse in breast cancer patients and more recently has also been reported to be linked to the codon 89 valine variant, which is itself associated with higher serum prostate-specific antigen levels in breast tumors and a more favorable breast cancer prognosis. We investigated whether the SRD5A2 (TA)(n) polymorphism was associated with risk of breast or ovarian cancer in Australian women by studying 946 breast cancer cases and 509 age-matched controls, and 544 ovarian cancer cases and 298 controls of similar age distribution. The (TA)(9) allele frequency was similar in breast cancer cases (0.110), breast cancer controls (0.125), ovarian cancer cases (0.106), and ovarian cancer controls (0.117). There was no difference in genotype distribution between breast cancer cases and controls (P = 0.5), ovarian cancer cases and controls (P = 0.7), or between the two control groups (P = 0.9). Genotypes containing at least one (TA)(9) allele were not significantly associated with risk of breast cancer overall (odds ratio, 0.86; 95% confidence interval, 0.67-1.12; P = 0.3) or in women stratified by age, menopausal status, or family history. Similarly, the (TA)(9) allele was not associated with risk of ovarian cancer (odds ratio, 0.87; 95% confidence interval, 0.61-1.23; P = 0.4) or with ovarian tumor behavior (invasive or low malignant potential), histology, stage, or grade. Given that this study had sufficient power to detect altered risks in the order of 1.4- to 1.7-fold, our results suggest that the SRD5A2 (TA)(9) allele is unlikely to be associated with moderate alterations in breast or ovarian cancer risk.

The effects of hormone replacement therapy on cortical bone in postmenopausal women. A histomorphometric study.

Investigations of the actions of estrogen on the skeleton have mainly focused on cancellous bone and there are no reported histomorphometric studies of the effects of oestrogen on cortical bone in humans. The aim of this study was to investigate the effects of both conventional hormone replacement therapy (HRT) and high-dose oestradiol on cortical bone in postmenopausal women. Transiliac biopsies were obtained from nine postmenopausal women aged 54-71 yr before and after 2 yr (mean, 23.5 months) of conventional HRT and in seven postmenopausal women aged 52-67 yr after long-term, high-dose oestradiol implant therapy (at least 14 yr). Indices of bone turnover, remodeling, and cortical structure were assessed by image analysis. Cortical width was highest in the women treated with high-dose oestrogen therapy (2.29 +/- 0.78 mm; mean +/- SD) and lowest in untreated women (1.36 +/- 0.60 mm; P=0.014). The proportion of canals with an eroded surface was significantly lower in the high-dose oestrogen group than in women before or after conventional HRT (3.03 +/- 3.7% vs. 11.1 +/- 7.1% and 10.5 +/- 8.6%; P=0.017 and 0.05, respectively). Bone formation rate (microm2/microm/day) in untreated women was significantly higher than in the high-dose oestrogen group (0.121 +/- 0.072 vs. 0.066 +/- 0.045, respectively; P=0.05), values in women treated with conventional HRT being intermediate. Our results provide the first histomorphometric evidence in postmenopausal women of dose-dependent oestrogen-induced suppression of bone turnover in iliac crest cortical bone. There was also a trend toward higher wall width with increasing dose of oestrogen, consistent with the previously reported anabolic effect in cancellous bone.

Evaluation of the potential interaction between NaCl and prostaglandin inhibition in elderly individuals with isolated systolic hypertension.

OBJECTIVE: To evaluate whether prostaglandin inhibition with the non-steroidal anti-inflammatory drug (NSAID), indomethacin (I) interacts synergistically with different doses of salt (NaCl) in elevating systolic blood pressure (SBP). DESIGN AND METHODS: This randomized, placebo-controlled, double-blind, crossover study examined the interaction between NaCl and the prostaglandin inhibitor, I in 31 healthy elderly individuals with a mean age (+/- SD) of 68.7+/-5.7 years (range 61-85 years). Participants aged more than 60 years on a 140 mmol/day NaCl dose for 6 weeks were chosen with normal blood pressure [24-h SBP <148 mm Hg, diastolic blood pressure (DBP) <85 mm Hg on the Takeda Ambulatory Blood Pressure Monitor (TABPM); n = 15] and isolated systolic hypertension (ISH), [24-h SBP >148 mm Hg, 24-h DBP <85 mm Hg on TABPM; n = 16]. Exclusion criteria included uncontrolled hypertension (SBP >220 mm Hg and/or DBP >110 mm Hg), cardiac disease, creatinine clearance <60 ml/min, dementia and recent cerebrovascular accident or secondary hypertension. A 2x2 Latin square design was structured using four treatment groups [low salt (NaCl = 90 mmol/day) + I placebo, high salt (NaCl = 240 mmol/day) + I placebo, low salt + I (25 mg three times daily) and high salt + I] for 2 weeks each, balanced and interspersed with 2 week washout periods to minimize carryover effects. Twenty-four hour SBP, DBP and heart rate were measured and summarized using a moving interval averaging technique. The mean change in 24-h SBP, DBP, heart rate, urinary Na+, K+, protein and creatinine, creatinine clearance and serum electrolytes were compared across treatments in the total cohort and in ISH and control groups separately using ANCOVA (SAS). RESULTS: In the total cohort, compared with low NaCl, chronic high NaCl increased mean SBP (5.76 mm Hg; P = 0.0002) and DBP (3.36 mm Hg; P = 0.002). Indomethacin significantly increased mean SBP (2.66 mm Hg, P = 0.015) but not DBP (0.31 mm Hg, P = 0.419). High salt and I were additive (SBPT, DBPT) but there was no interaction (P = 0.795 and P = 0.739, respectively). Additionally, chronic high NaCl increased serum Na (P = 0.0001) and 24-h urinary Na (P = 0.0001) as expected. Indomethacin significantly decreased mean heart rate (P = 0.018). The effects of NaCl and I on SBP, DBP and heart rate were not modified by age, alcohol intake, serum K+, body mass index or treatment order. In the ISH group, NaCl dose significantly elevated SBP (9.87 mm Hg; P = 0.0001) and DBP (5.26 mm Hg, P = 0.006) but did not significantly alter blood pressure in the normotensive group. Indomethacin significantly elevated SBP (P = 0.03) in normotensive individuals but had no effect on blood pressure in the ISH group. CONCLUSIONS: Chronic high salt diet elevated blood pressure more than I in the total cohort of elderly individuals. No interaction was demonstrated and their effects were additive. In the ISH group, chronic high salt diet significantly increased SBP and DBP while I failed to alter blood pressure. In the normotensive group, I, but not salt, elevated SBP. Patients with ISH are sensitive to the pressor effect of NaCl but resistant to the pressor effect of prostaglandin inhibition in contrast to elderly normotensive control individuals where the reverse was found.

A comparison of the effects of dialysis and renal transplantation on the survival of older uremic patients.

BACKGROUND: Patients over age 60 constitute half of all new patients accepted into the renal replacement therapy programs in Australia. However, the optimal treatment of their end-stage renal disease remains controversial. The aim of the present study was to compare survival for dialysis and renal transplantation in older patients who were rigorously screened and considered eligible for transplantation. METHODS: The study cohort consisted of 174 consecutive patients over 60 who were accepted on to the Queensland cadaveric renal transplant waiting list between January 1, 1993 and December 31, 1997. Follow-up was terminated on October 1, 1998. Data were analyzed on an intention-to-transplant basis using a Cox regression model with time-varying explanatory variables. An alternative survival analysis was also performed, in which patients no longer considered suitable for transplantation were censored at the time of their removal from the waiting list. RESULTS: There were 67 patients receiving a renal transplant, whereas the other 107 continued to undergo dialysis. These two groups were well matched at baseline with respect to age, gender, body mass index, renal disease etiology, comorbid illnesses, and dialysis duration and modality. The overall mortality rate was 0.096 per patient-year (0.131 for dialysis and 0.029 for transplant, P<0.001). Respective 1-, 3- and 5-year survivals were 92%, 62%, and 27% for the dialysis group and 98%, 95%, and 90% (P<0.01) for the transplant group. Patients in the transplant group had an adjusted hazard ratio 0.16 times that of the dialysis group (95% confidence interval 0.06-0.42). If patients were censored at the time of their withdrawal from the transplant waiting list, the adjusted hazard ratio was 0.24 (95% confidence interval 0.09-0.69). CONCLUSIONS: Renal transplantation seems to confer a substantial survival advantage over dialysis in patients with end-stage renal failure who are rigorously screened and considered suitable for renal transplantation.

Measurement of parathyroid hormone-related protein in extracts of fetal parathyroid glands and placental membranes.

A radioimmunoassay based on an antiserum to human parathyroid hormone-related protein PTHrP(1-16) was used with PTHrP(1-34) standard to measure the concentration of immunoreactive PTHrP in extracts of fetal parathyroid glands from lambs and calves and also placental membranes obtained from several species, including man. Dilution curves from these sources were parallel to those obtained for PTHrP(1-34) standard. It was demonstrated that this parallelism was not the result of tracer damage caused by enzymic activity in the tissue extracts. Extracts of human placental membranes were subjected to high-pressure liquid chromatography with a linear acetonitrile gradient. Co-elution of cytochemical biological activity with 125I-labelled PTHrP(1-34) was noted. These results provide further evidence for both the fetal parathyroid glands and the placenta containing material resembling PTHrP which may be responsible for sustaining the activity of the placental calcium pump which maintains the fetus hypercalcaemic relative to its mother.

Matching prescription claims with medication data for nursing home residents: implications for prescriber feedback, drug utilisation studies and selection of prescription claims database.

Medication data retrieved from Australian Repatriation Pharmaceutical Benefits Scheme (RPBS) claims for 44 veterans residing in nursing homes and Pharmaceutical Benefits Scheme (PBS) claims for 898 nursing home residents were compared with medication data from nursing home records to determine the optimal time interval for retrieving claims data and its validity. Optimal matching was achieved using 12 weeks of RPBS claims data, with 60% of medications in the RPBS claims located in nursing home administration records, and 78% of medications administered to nursing home residents identified in RPBS claims. In comparison, 48% of medications administered to nursing home residents could be found in 12 weeks of PBS data, and 56% of medications present in PBS claims could be matched with nursing home administration records. RPBS claims data was superior to PBS, due to the larger number of scheduled items available to veterans and the veteran's file number, which acts as a unique identifier. These findings should be taken into account when using prescription claims data for medication histories, prescriber feedback, drug utilisation, intervention or epidemiological studies.

Indices to quantify changes in intracranial and cerebral perfusion pressure by assessing agreement between hourly and semi-continuous recordings.

OBJECTIVES: Little published data exists on whether nurse-recorded end-hour values of intracranial pressure (ICP) and cerebral perfusion pressure (CPP) are representative of continuous monitoring during the hour. There is also no standard method of quantifying the observed perturbations in cerebral hemodynamics. This study compared the level of agreement between end-hour values and computer downloaded observations of ICP and CPP at 15-min intervals. We also developed the intracranial hypertension index and the cerebral hypoperfusion index to quantify perturbations in cerebral hemodynamics. Each of these indices relates the number of abnormal observations to the total number of observations taken. METHODS: Prospective, non-interventional study. RESULTS: The bias and precision between the two methods for ICP and CPP were -0.002+/-2.6 mmHg and -1.1+/-6.2 mmHg, respectively. A strong correlation existed between the hourly mean calculated from the 15-min and the end-hour values for both ICP ( r(2)=0.95, p<0.0001) and CPP ( r(2)=0.78, p<0.001). The intracranial hypertension index was 40% from the 15-min measurements and 41% from the hourly observations ( p= NS). The cerebral hypoperfusion indices were 13.4% and 13.1% with the 15-min and end-hour values, respectively ( p= NS). CONCLUSIONS: The end-hour values of ICP and CPP are as accurate as more frequent measurements during the hour and are adequate for purposes of epidemiological research and medico-legal audit. The intracranial hypertension and cerebral hypoperfusion indices may be useful in describing cerebral hemodynamics for future interventional studies and for assessing quality in the delivery of neuro-critical care.