Prior differences in previous trauma exposure primarily drive the observed racial/ethnic differences in posttrauma depression and anxiety following a recent trauma

BACKGROUND

Racial and ethnic groups in the USA differ in the prevalence of posttraumatic stress disorder (PTSD). Recent research however has not observed consistent racial/ethnic differences in posttraumatic stress in the early aftermath of trauma, suggesting that such differences in chronic PTSD rates may be related to differences in recovery over time.

METHODS

As part of the multisite, longitudinal AURORA study, we investigated racial/ethnic differences in PTSD and related outcomes within 3 months after trauma. Participants (n = 930) were recruited from emergency departments across the USA and provided periodic (2 weeks, 8 weeks, and 3 months after trauma) self-report assessments of PTSD, depression, dissociation, anxiety, and resilience. Linear models were completed to investigate racial/ethnic differences in posttraumatic dysfunction with subsequent follow-up models assessing potential effects of prior life stressors.

RESULTS

Racial/ethnic groups did not differ in symptoms over time; however, Black participants showed reduced posttraumatic depression and anxiety symptoms overall compared to Hispanic participants and White participants. Racial/ethnic differences were not attenuated after accounting for differences in sociodemographic factors. However, racial/ethnic differences in depression and anxiety were no longer significant after accounting for greater prior trauma exposure and childhood emotional abuse in White participants.

CONCLUSIONS

The present findings suggest prior differences in previous trauma exposure partially mediate the observed racial/ethnic differences in posttraumatic depression and anxiety symptoms following a recent trauma. Our findings further demonstrate that racial/ethnic groups show similar rates of symptom recovery over time. Future work utilizing longer time-scale data is needed to elucidate potential racial/ethnic differences in long-term symptom trajectories.

Neuroendocrine stress response is moderated by sex and sex hormone receptor polymorphisms

Sex hormones are significant regulators of stress reactivity, however, little is known about how genetic variation in hormone receptors contributes to this process. Here we report interactions between biological sex and repeat polymorphisms in genes encoding sex hormone receptors, and their effects on salivary cortisol reactivity in a sample of 100 participants (47 men & 53 women; 24.7 ± 3.23 years). Three genes were investigated: estrogen receptors alpha (ESR1) and beta (ESR2), and the androgen receptor (AR). Participants were classified as carrying 'Short' or 'Long' alleles based on median splits of the repeat distribution for each gene. Measures of physiological reactivity were collected before and after exposure to a canonical laboratory stressor and converted to traditional summary measures for analyses. Overall, men exhibited greater cortisol (p = 0.001) and mean arterial pressure reactivity (p = 0.002), while women displayed elevated heart rate throughout the session (p = 0.02). The effect of polymorphisms on salivary cortisol was sex sensitive. ESR1 was associated with differential reactivity in men (p = 0.04), but not women (p = 0.24). ESR2 genotype interacted with sex such that each additional 'Long' allele was associated with a 6.4% decrease in salivary cortisol in men, but a 9.5% increase in the levels of women (p = 0.02 for interaction). For the X-linked AR, the 'Long' allele was associated with decreased cortisol levels in men (p = 0.047), but in women had no effect (p = 0.75). Together, these results provide evidence for the saliency of genetic variation in sex hormone receptors on stress reactivity in humans and highlight their important role as mediators of hormonal activity.

Randomized double-blind clinical trial comparing basal insulin peglispro and insulin glargine, in combination with prandial insulin lispro, in patients with type 2 diabetes: IMAGINE 4

AIMS

To evaluate the efficacy and safety of basal insulin peglispro (BIL) with those of insulin glargine, both in combination with prandial insulin lispro, in patients with type 2 diabetes (T2D).

METHODS

In this phase III, multicentre, double-blind, 26-week study, we randomized patients with T2D [glycated haemoglobin (HbA1c) ≥7 and <12%, on ≥1 insulin injections daily) to BIL (n = 691) or glargine (n = 678), in combination with lispro.

RESULTS

At week 26, the primary objective of non-inferiority of BIL versus glargine for HbA1c reduction was achieved (least squares mean difference -0.21%; 95% confidence interval -0.31 to -0.11%), with statistical superiority of BIL with multiplicity adjustment (p < 0.001). HbA1c at baseline was 8.4% versus 8.5% for BIL versus glargine and at 26 weeks it was 6.8% versus 7.0%. At 26 weeks, more patients reached HbA1c <7% with BIL than with glargine (63.3% vs 53.3%; p < 0.001), the nocturnal hypoglycaemia rate (≤3.9 mmol/l) was lower with BIL (0.51 vs 0.92 events/30 days; p < 0.001), but the daytime hypoglycaemia rate was higher with BIL (5.47 vs 4.53 events/30 days; p < 0.001). The total hypoglycaemia relative rate was 1.10 (p = 0.053). At 26 weeks, patients in the BIL group had lower fasting serum glucose levels, higher basal insulin dosing, with no statistically significant difference in prandial or total insulin dosing, reduced glucose variability and less weight gain (1.3 kg vs 2.2 kg) compared with the glargine group. The BIL group had higher mean triglyceride and aminotransferase levels.

CONCLUSIONS

In patients with T2D, BIL with insulin lispro provided greater improvement in glycaemic control with less nocturnal hypoglycaemia, lower glucose variability and less weight gain compared with glargine. The daytime hypoglycaemia rate and mean triglyceride and aminotransferase levels were higher with BIL.

Different effects of basal insulin peglispro and insulin glargine on liver enzymes and liver fat content in patients with type 1 and type 2 diabetes

AIMS

To compare effects of basal insulin peglispro (BIL), a hepatopreferential insulin, to insulin glargine (glargine) on aminotransferases and liver fat content (LFC) in patients with type 1 and type 2 diabetes (T1D, T2D).

MATERIALS AND METHODS

Data from two Phase 2 and five Phase 3 randomized trials comparing BIL and glargine in 1709 T1D and 3662 T2D patients were integrated for analysis of liver laboratory tests. LFC, measured by magnetic resonance imaging (MRI) at baseline, 26 and 52 weeks, was analyzed in 182 T1D patients, 176 insulin-naïve T2D patients and 163 T2D patients previously treated with basal insulin.

RESULTS

Alanine aminotransferase (ALT) increased in patients treated with BIL, was higher than in glargine-treated patients at 4-78 weeks (difference at 52 weeks in both T1D and T2D: 7 international units/litre (IU/L), P < .001), and decreased after discontinuation of BIL. More BIL patients had ALT ≥3× upper limit of normal (ULN) than glargine. No patient had ALT ≥3× ULN with bilirubin ≥2× ULN that was considered causally related to BIL. In insulin-naїve T2D patients, LFC decreased with glargine but was unchanged with BIL. In T1D and T2D patients previously treated with basal insulin, LFC was unchanged with glargine but increased with BIL. In all three populations, LFC was higher after treatment with BIL vs glargine (difference at 52 weeks: 2.2% to 5.3%, all P < .01).

CONCLUSIONS

Compared to glargine, patients treated with BIL had higher ALT and LFC at 52-78 weeks. No severe drug-induced liver injury was apparent with BIL treatment for up to 78 weeks.

Site-Specific Neutrophil Migration and CXCL2 Expression in Periodontal Tissue

The oral microbial community is the best-characterized bacterial ecosystem in the human host. It has been shown in the mouse that oral commensal bacteria significantly contribute to clinically healthy periodontal homeostasis by influencing the number of neutrophils that migrate from the vasculature to the junctional epithelium. Furthermore, in clinically healthy tissue, the neutrophil response to oral commensal bacteria is associated with the select expression of the neutrophil chemokine CXCL2 but not CXCL1. This preliminary study examined the contribution of commensal bacteria on neutrophil location across the tooth/gingival interface. Tissue sections from the root associated mesial (anterior) of the second molar to the root associated distal (posterior) of the second molar were examined for neutrophils and the expression of the neutrophil chemokine ligands CXCL1 and CXCL2. It was found that both the number of neutrophils as well as the expression of CXCL2 but not CXCL1 was significantly increased in tissue sections close to the interdental region, consistent with the notion of select tissue expression patterns for neutrophil chemokine expression and subsequent neutrophil location. Furthermore, mice gavaged with either oral Streptococcus or Lactobacillus sp. bacteria induced a location pattern of neutrophils and CXCL2 expression similar to the normal oral flora. These data indicate for the first time select neutrophil location and chemokine expression patterns associated with clinically healthy tissue. The results reveal an increased inflammatory load upon approaching the interproximal region, which is consistent with the observation that the interproximal region often reveals early clinical signs of periodontal disease.

Peer supporters for cardiac patients with diabetes: a randomized controlled trial

AIMS

To determine whether incorporation of patient peer supporters in a Cardiac-Diabetes Self-Management Program (Peer-CDSMP) led to greater improvement in self-efficacy, knowledge and self-management behaviour in the intervention group compared to a control group.

BACKGROUND

Promoting improved self-management for those with diabetes and a cardiac condition is enhanced by raising motivation and providing a model. Peer support from former patients who are able to successfully manage similar conditions could enhance patient motivation to achieve better health outcomes and provide a model of how such management can be achieved. While studies on peer support have demonstrated the potential of peers in promoting self-management, none have examined the impact on patients with two co-morbidities.

METHODS

A randomized controlled trial was used to develop and evaluate the effectiveness of the Peer-CDSMP from August 2009 to December 2010. Thirty cardiac patients with type 2 diabetes were recruited. The study commenced in an acute hospital, follow-up at participants' homes in Brisbane, Australia.

RESULTS

While both the control and intervention groups had improved self-care behaviour, self-efficacy and knowledge, the improvement in knowledge was significantly greater for the intervention group.

CONCLUSIONS

Significant improvement in knowledge was achieved for the intervention group. Absence of significant improvements in self-efficacy and self-care behaviour represents an inconclusive effect; further studies with larger sample sizes are recommended.

Switching currents limited by single phase slips in one-dimensional superconducting Al nanowires

An aluminum nanowire switches from superconducting to normal as the current is increased in an upsweep. The switching current (I(s)) averaged over upsweeps approximately follows the depairing critical current (I(c)) but falls below it. Fluctuations in I(s) exhibit three distinct regions of behaviors and are nonmonotonic in temperature: saturation well below the critical temperature T(c), an increase as T(2/3) at intermediate temperatures, and a rapid decrease close to T(c). Heat dissipation analysis indicates that a single phase slip is able to trigger switching at low and intermediate temperatures, whereby the T(2/3) dependence arises from the thermal activation of a phase slip, while saturation at low temperatures provides striking evidence that the phase slips by macroscopic quantum tunneling.

1/f Noise in the Tunneling Current of thin Gate Oxides

We have observed fluctuations in the tunneling current through 3.5 nm gate oxides with a 1/f power spectrum where f is the frequency. For voltages in the direct tunneling regime we lind an anomalous current dependence of the noise relative to previous observations of noise in thin oxides. We present a simplified model for the current noise in terms of fluctuations in a trap assisted tunneling current that exists in the oxide in addition to the direct tunneling current. Current noise appears to be a very sensitive probe of trap assisted tunneling and degradation in oxides.

Innovative self-management programme for diabetics following coronary care unit admission

BACKGROUND

Evidence indicates self-management programmes based on improving self-efficacy in managing diabetes can reduce the risk of a further cardiac event. Many current cardiac rehabilitation or diabetes self-management programmes do not address the needs of people with both type 2 diabetes and a critical cardiac condition in their transition from coronary care unit (CCU) to home.

AIMS/METHODS

The aim was to develop and pilot test a Cardiac-Diabetes Self-Management Program (CDSMP) using an experimental design.

FINDINGS/CONCLUSION

Results demonstrated the feasibility of the CDSMP for CCU patients with type 2 diabetes in their transition to home, and a full study is warranted.

Crystal orientation and thickness dependence of the superconducting transition temperature of tetragonal FeSe1-x thin films

Superconductivity was recently found in the tetragonal phase FeSe. A structural transformation from tetragonal to orthorhombic (or monoclinic, depending on point of view) was observed at low temperature, but was not accompanied by a magnetic ordering as commonly occurs in the parent compounds of FeAs-based superconductors. Here, we report the correlation between structural distortion and superconductivity in FeSe(1-x) thin films with different preferred growth orientations. The films with preferred growth along the c axis show a strong thickness dependent suppression of superconductivity and low temperature structural distortion. In contrast, both properties are less affected in the films with (101) preferred orientation. These results suggest that the low temperature structural distortion is closely associated with the superconductivity of this material.

Audit of patients with type 2 diabetes following a critical cardiac event

BACKGROUND

Evidence indicates that type 2 diabetes leads to complications such as a cardiac event, which often requires admission to a coronary care unit (CCU). Although there is a considerable body of knowledge about the management and characteristics of people with type 2 diabetes and myocardial infraction, there are few reports of the disease and demographic characteristics of the entire group of patients with diabetes admitted to a CCU.

PURPOSE

To gain greater understanding of the characteristics of patients with diabetes hospitalized for a critical cardiac event in order to assist in the development of an appropriate self-management programme for CCU patients with diabetes.

METHODS

Data were collected retrospectively from computerized records and charts of all patients with diabetes admitted to the CCU from 1 January 2000 to 31 December 2003.

FINDINGS

The proportion of type 2 diabetic patients admitted to CCU with a critical cardiac event over the 4-year study period was consistent at 14.7%, 233 in 1589 patients. More than 22% of CCU patients with diabetes were readmitted to hospital within 28 days compared with only 6% of CCU patients without diabetes. Predictors for readmission and length of stay were also examined.

CONCLUSIONS

A considerable proportion of a CCU population had type 2 diabetes and these patients had significantly higher readmission rates. The implications of this study for the development of a self-management programme for patients with diabetes who experienced a critical cardiac event are discussed.

IMPLICATIONS FOR PRACTICE

Innovative programmes are required to reduce the rate of readmission for patients with both diabetes and a critical cardiac event. These should: 1 ensure transition programmes, such as self-management, commence within the CCU environment and continue following discharge, and 2 integrate diabetes and cardiac self-management programmes to condense the large amount of information provided to patients for managing two serious conditions.

Evidence for macroscopic quantum tunneling of phase slips in long one-dimensional superconducting Al wires

Quantum phase slips have received much attention due to their relevance to superfluids in reduced dimensions and to models of cosmic string production in the early universe. Their establishment in one-dimensional superconductors has remained controversial. Here we study the nonlinear current-voltage characteristics and linear resistance in long superconducting Al wires with lateral dimensions approximately 5 nm. We find that, in a magnetic field and at temperatures well below the superconducting transition, the observed behaviors can be described by the nonclassical, macroscopic quantum tunneling of phase slips, and are inconsistent with the thermal activation of phase slips.

Patient-controlled analgesia versus conventional intramuscular injection: a cost effectiveness analysis

BACKGROUND

In previous studies comparing patient-controlled-analgesia and intramuscular pain management have been unable to provide conclusive evidence of the benefits of either method of postoperative pain control.

AIM

The purpose of the study was to compare the efficacy and cost-effectiveness of intravenous patient-controlled-analgesia with intermittent intramuscular morphine for Chinese women in the first 24 hours following elective gynaecological surgery.

METHODS

A randomized control design was used. The main outcomes were level of pain and cost for the two types of pain management. Participants indicated their level of pain at rest and when deep breathing or coughing on a 100 mm Visual Analogue Scale, on seven occasions within 24 postoperative hours. Costs for the two types of pain management were based on the costs of equipment, drugs and nursing time.

RESULTS

A total of 125 women participated in the study. Mean pain level over the 24 hours in the patient-controlled-analgesia group was significantly lower than in the intramuscular group (P < 0.001). Mean pain level over the seven occasions for the patient-controlled-analgesia group was 11.83 points (95% CI 7.14-16.52) lower when at rest and 11.73 points (95% CI 5.96-17.50) lower during motion than the intramuscular group. Cost per patient was $81.10 (Hong Kong) higher for patient-controlled-analgesia than for intramuscular pain management. Women in the patient-controlled-analgesia group had significantly greater satisfaction with pain management than those in the intramuscular group (P < 0.001), but reported significantly more episodes of nausea (P < 0.05).

CONCLUSIONS

While patient-controlled-analgesia was more costly, it was also more effective than conventional on-demand intramuscular opioid injections after laparotomy for gynaecological surgery.

Prevention of oral mucositis in paediatric patients treated with chemotherapy

This study compared the efficacy of two protocols for oral care using either chlorhexidine or benzydamine as oral rinses to alleviate mucositis in children undergoing chemotherapy. Eligible participants were randomised to receive either protocol for 3 weeks in a two-period crossover design. The occurrence of ulcerative lesions and severity of mucositis were measured at baseline and twice weekly, using the modified Oral Assessment Guide (OAG). Data were continuously analysed by plotting them directly on predefined sequential charts. According to this sequential analysis, the study could be terminated at the 34th within subject comparison, with a statistically significant reduction in ulcerative lesions (P<0.05) and severity of mucositis (P<0.05) in children on the chlorhexidine protocol. These findings suggest that chlorhexidine together with oral care might be helpful in alleviating mucositis when given prophylactically to children on chemotherapy, but the therapeutic benefit needs to be confirmed in a larger trial.

Transition between quantum states in a parallel-coupled double quantum dot

Strong electron and spin correlations in a double quantum dot (DQD) can give rise to different quantum states. We observe a continuous transition from a Kondo state exhibiting a single-peak Kondo resonance to another exhibiting a double peak by increasing the interdot coupling (t) in a parallel-coupled DQD. The transition into the double-peak state provides evidence for spin entanglement between the excess electrons on each dot. Toward the transition, the peak splitting merges and becomes substantially smaller than t because of strong Coulomb effects. Our device tunability bodes well for future quantum computation applications.

Palliation of Oral Mucositis Symptoms in Pediatric Patients Treated With Cancer Chemotherapy

This prospective randomized 2-period crossover study aimed at comparing the efficacy of 2 oral care protocols differing in the type of mouthwashes: chlorhexidine versus benzydamine in alleviating oral mucositis symptoms for children undergoing chemotherapy. Forty subjects were randomly allocated to receive either chlorhexidine first then benzydamine protocols or benzydamine first then chlorhexidine protocols. Each protocol was started on the first day of chemotherapy and continued for 21 days. Subjects were evaluated in intervals of 3 to 4 days using the World Health Organization (WHO) grading for mucositis and 10-cm visual analogue scale for oral symptoms evaluations. Among 34 evaluable subjects, 26% and 48% of them using chlorhexidine and benzydamine had WHO grade II mucositis, respectively (P < .05). The results revealed a significant difference in mean area under the curve (AUC) of mouth pain (1.35 +/- 2.26 versus 3.09 +/- 3.21) (P = .05), and a trend of a lessening of mean AUC of difficulty in eating/chewing (2.49 +/- 3.74 versus 2.71 +/- 4.1) (P = .82) and swallowing (1.34 +/- 3.31 versus 1.91 +/- 4.03) (P = .53) for subjects receiving chlorhexidine compared to those receiving benzydamine. In conclusion, chlorhexidine may be helpful in palliating mucositis symptoms for children in chemotherapy. The beneficial effect, however, is small and needs to be confirmed in a larger trial.

Compliance with a pelvic muscle exercise program as a causal predictor of urinary stress incontinence amongst Chinese women

AIM

To determine the importance and contribution of compliance in a pelvic muscle exercise program as a factor in reducing the severity of urinary stress incontinence amongst Chinese women.

METHODS

Two hundred fourteen women presenting with urinary stress incontinence who agreed to undertake a program of pelvic muscle exercises were recruited into the study. Incontinence (wetting episodes), pelvic muscle strength, exercises compliance, correctness of pelvic muscle exercise technique, duration of stress incontinence, and previous history of pelvic surgery were recorded on four occasions: baseline (first clinic session) and second to fourth clinic sessions. Demographic data were also collected at baseline. Stepwise multiple regression analyses were used to determine the relative importance of compliance to exercise regime in predicting the severity of incontinence. Path analysis was used to provide a summary description of the influence of compliance on the outcomes over the four visits.

RESULTS

The pelvic muscle training program appears to be able to reduce the overall urinary incontinence episodes by 85.2% and achieved a 73.1% increase in pelvic muscle strength. Although the number of wetting episodes in any visit are causally linked to that recorded in previous visit, those who were more compliant had a greater reduction. Age, mode of delivery, menopausal status, history of pelvic surgery, and duration of incontinence did not appear to contribute significantly to predicting incontinence.

CONCLUSION

Compliance with pelvic muscle exercises significantly contributed to a reduction in urinary stress incontinence.

An oral care protocol intervention to prevent chemotherapy-induced oral mucositis in paediatric cancer patients: a pilot study

The likelihood of paediatric cancer patients experiencing oral mucositis has increased significantly as high-dose and multiple chemotherapy agents are used in the treatment of childhood cancer in recent years. The resulting oral ulcerative lesions can cause significant pain, dysphagia, alteration in nutritional status and increased risk for localized infections that could disseminate systemically. The purpose of this pilot study was to determine the clinical benefits of an oral care protocol intervention on the prevention and reduction of the severity of oral mucositis in paediatric patients receiving chemotherapy. Fourteen children were enrolled in the study; there were seven children in the control and seven in the experimental group. In the experimental group, children received a preventive oral care protocol consisting of tooth brushing, normal saline rinse and 0.2% chlorhexidine mouth rinse. Children in the control group received usual care according to the study's clinical setting. Data were collected at baseline, then twice a week for 3 weeks. The incidence of ulcerative lesions, severity of oral mucositis and the related pain intensity were used as the main outcome variables. The experimental group exhibited fewer and less painful oral mucositis lesions. The results of this study support the preventive use of oral care protocols in paediatric patients undergoing chemotherapy for cancer treatment.

Predictors of quality of life following stroke

PURPOSE

To determine the factors predicting quality of life during the course of rehabilitation following stroke.

METHOD

Two hundred and fifteen stroke patients aged 41 93 were studied over a period of three months. Measurement of quality of life, functional ability, social support. demographic and treatment data were taken on admission to the rehabilitation hospital, at two weeks and three months. The instruments used were the Sickness Impact Profile (SIP), the Modified Barthel Index (MBI) and The Social Support Questionnaire, short form (SSQ6).

RESULTS

Length of stay, previous stroke, functional ability and social support were found to be significantly correlated with quality of life. Stepwise multiple regression analysis indicated that functional ability, psychological and physical SIP dimensions, social support satisfaction at two weeks and previous stroke explained 47% of the variance in sickness impact at three months following stroke. The factors predicting 53% of the variance in sickness impact at two weeks were baseline functional ability, psychological and physical SIP.

CONCLUSIONS

The findings indicate that both psychosocial and physical factors are important in predicting quality of life in stroke rehabilitation. Determining such predictors at an early stage will help to guide clinical decisions throughout rehabilitation.

Oxidative stress in the fetal lamb brain following intermittent umbilical cord occlusion: a path analysis

OBJECTIVE

To evaluate the relative contribution of cord occlusion length intervals between occlusions and experimental duration on oxidative stress in the fetal lamb brain.

DESIGN

Acute, partially exteriorised fetal lambs with intermittent total cord occlusion.

SETTING

The Vivarium of Westmead Hospital, University of Sydney, Australia and The Chinese University of Hong Kong.

MAIN OUTCOME MEASURES

Arterio-venous differences in the concentration of organic hydroperoxides, measured in paired samples of carotid arterial and jugular venous blood, as an index of oxidative stress in the brain.

METHODS

Thirty-two fetal lambs were exposed to graded hypoxia, induced by intermittent total umbilical cord compression of 30 seconds, 60 seconds and 90 seconds duration, occurring every minute for a total of 27 occlusions over 81 minutes. Three sham experiments were also performed. In addition to organic hydroperoxides, carotid arterial blood samples were also assayed in 15 animals (two sham) for oxygen saturation, pH, hypoxanthine, xanthine and urate concentrations. A causal model for oxidative stress was defined: occlusions leading to hypoxia with a rise in hypoxanthine; reperfusion during intervals between occlusions leading to the accelerated production of xanthine and uric acid and the generation of oxygen free radicals, which in turn, are responsible for the rise in lipid peroxidation. Path analysis was performed to assess the strength of the relationships between these variables and the cord occlusion length, the interval between occlusions and the duration of the experiment.

RESULTS

Sham experiments showed no change in organic hydroperoxide production. Following 30-second umbilical cord occlusions a sixfold drop in mean organic hydroperoxides was observed between carotid arterial and jugular venous levels. In contrast, following occlusions of 60 seconds duration (or longer) a median 20-fold increase in organic hydroperoxide production was observed. Path analysis revealed a strong indirect pathway from occlusion length --> hypoxanthine --> urate and weak positive pathways from oxygen saturation --> urate and from interval between occlusions --> urate. After accounting for these pathways reflecting oxidative stress, a strong direct path remained from time from first occlusion --> organic hydroperoxide production.

CONCLUSIONS

Peroxidation of lipids in the brain occurs under conditions of severe hypoxia and reperfusion associated with intermittent umbilical cord occlusions of 60 seconds or longer. The path analysis supported the causal model as originally defined, with the exception that the indirect pathway via pH was found to be trivial.

Preclinical ex vivo expansion of cord blood hematopoietic stem and progenitor cells: duration of culture; the media, serum supplements, and growth factors used; and engraftment in NOD/SCID mice

BACKGROUND

Ex vivo expansion of cord blood (CB) hematopoietic stem and progenitor cells increases cell dose and may reduce the severity and duration of neutropenia and thrombocytopenia after transplantation. This study's purpose was to establish a clinically applicable culture system by investigating the use of cytokines, serum-free media, and autologous plasma for the expansion of CB cells and the engraftment of expanded product in nonobese diabetic/severe combined immunodeficient (NOD/SCID) mice.

STUDY DESIGN AND METHODS

Enriched CB CD34+ cells were cultured in four media (Iscove's modified Dulbecco's medium with FCS, Gibco; X-Vivo-10, BioWhittaker; QBSF-60, Quality Biological; and StemSpan SFEM, Stem Cell Technologies) with four cytokine combinations (thrombopoietin [TPO], SCF, Flt-3 ligand [FL] with and without G-CSF, and/or IL-6). The effect of autologous CB plasma was also investigated. The read-out measures were evaluated on Days 8 and 12. After expansion at the optimized condition, cultured cells were transplanted into sublethally irradiated NOD/SCID mice. The engraftment of human CD45+ cells and subsets in the bone marrow, spleen, and peripheral blood was determined.

RESULTS

QBSF-60 or StemSpan SFEM supported high yields of early progenitors (CD34+ cells, <or= 64.8-fold; CD34+CD38- cells, 330-fold; CFU-granulocyte erythroid macrophage megakaryocyte [GEMM], 248-fold) and CFUs of the myeloid (CFU-GM, 407-fold) and erythroid (BFU/CFU-E, 144-fold) lineages. The expansion of the megakaryocytic lineage was consistently higher in X-Vivo-10 (CFU-megakaryocyte, 684-fold). Autologous plasma promoted colony formation but reduced CD34+ cells and CFU-GEMM. The addition of G-CSF or IL-6 improved cell yields; G-CSF was more effective for committed progenitors. Expansion products from cultures in QBSF-60 with the cytokines engrafted and differentiated into the myeloid and lymphoid lineages in NOD/SCID mice.

CONCLUSION

The data supported the strategy of expansion. The optimized condition may be applicable to clinical expansion for the abrogation or reduction of posttransplant cytopenia.

Evaluation of an oral care protocol intervention in the prevention of chemotherapy-induced oral mucositis in paediatric cancer patients

Oral mucositis is the most frequent and severe complication of chemotherapy in children with cancer that can aggravate the child's clinical condition and increase the risk of infection. This prospective comparative study was designed to determine the effectiveness of a preventive oral care protocol in reducing chemotherapy-induced oral mucositis in children with cancer. During an 8-month period, 42 children aged 6 to 17 years with haematological malignancies or solid tumours were evaluated. The 21 children who were included in the first 4-month period of the study constituted the control group. Another 21 children were enrolled in the subsequent 4 months and were assigned to the experimental group, in which they were given an oral care protocol intervention. The oral care protocol consisted of tooth brushing, 0.2% chlorhexidine mouth rinse and 0.9% saline rinse. Children in both groups were evaluated twice a week for 3 weeks. The incidence of ulcerative lesions, severity of oral mucositis and the related pain intensity were used as the main outcome variables. A 38% reduction in the incidence of ulcerative mucositis was found in children using the oral care protocol compared with children in the control group. The severity of oral mucositis (P=0.000002) and the related pain (P=0.0001) were significantly reduced with the intervention. These results support the preventive use of the oral care protocol in paediatric cancer patients who undergo chemotherapy for cancer treatment.

Effects of using videotaped vignettes on enhancing students' critical thinking ability in a baccalaureate nursing programme

AIM

The aim of this study was to determine the effects of using videotaped vignettes in promoting nursing students' critical thinking abilities in managing different clinical situations.

BACKGROUND

The impetus for undertaking this study came from recognition of the need to develop the level of students' critical thinking within clinical nursing practice. Eight videotaped vignettes that simulated clinical situations were developed to promote baccalaureate nursing students' critical thinking abilities in managing clinical situations. Guidelines were also developed to stimulate students' discussion.

DESIGN/METHODS

A pre-test/post-test design was employed to determine the effectiveness of videotaped vignettes in promoting critical thinking skills among these students. A final sample of 83 students completed all the pre-test and post-test questionnaires on critical thinking skills and nursing knowledge test specific to a vignette.

RESULTS/FINDINGS

The findings indicate that students' post-test knowledge scores were significantly higher than the pre-test knowledge scores. While the post-test critical thinking skill test scores were slightly higher than those of the pre-test for the students, the difference was not significant. One reason for such findings may be the limited exposure students had to these new types of videotaped vignettes. After the course had been completed both students and teachers were asked to reflect and to indicate their level of satisfaction with the new approach. There was overall satisfaction with the new approach to teaching clinical skills as reflected in the interview data from both teachers and students.

CONCLUSIONS

While there were positive outcomes in terms of helping students to relate nursing principles to clinical situations, more time for students to learn using videotaped vignette in tutorial hours remains a challenge for teachers in planning the lectures.

The Kondo effect in an artificial quantum dot molecule

Double quantum dots provide an ideal model system for studying interactions between localized impurity spins. We report on the transport properties of a series-coupled double quantum dot as electrons are added one by one onto the dots. When the many-body molecular states are formed, we observe a splitting of the Kondo resonance peak in the differential conductance. This splitting reflects the energy difference between the bonding and antibonding states formed by the coherent superposition of the Kondo states of each dot. The occurrence of the Kondo resonance and its magnetic field dependence agree with a simple interpretation of the spin status of a double quantum dot.

Psychosocial correlates of fluid compliance among Chinese haemodialysis patients

AIMS

The present study was designed to determine the psychosocial correlates of fluid compliance among patients receiving haemodialysis at two Hong Kong renal dialysis centres.

BACKGROUND

There has been little consistency in the findings of correlations among any psychosocial variables and compliance behaviour. There is a need to further study these variables in an attempt to predict haemodialysis patient compliance to fluid restriction.

METHODS

Ninety-two Chinese haemodialysis patients completed the Center for Epidemiological Studies Depression Scale (CES-D), The Multidimensional Health Locus of Control Form C Scale (MHLC), the Social Support Questionnaire, Short Form Scale (SSQ6) and a self-designed socio-demographic questionnaire. Daily interdialytic weight gain (DIWG) measure was used as an indicator of fluid compliance.

RESULTS

The prevalence of compliance behaviour of Chinese haemodialysis patients was higher than that reported in western studies. There were significant negative correlations found between DIWG and total score on internal health locus of control and social support satisfaction score. However, internal health locus of control did not predict a significant portion of the DIWG variance. Significant predictors of DIWG included satisfaction with social support, comorbidity and monthly family income. Satisfaction with social support was the largest predictor of DIWG.

CONCLUSIONS

The present findings suggest that assessing family income, comorbidity, and satisfaction with social support may be useful in identifying haemodialysis patients potentially at risk for difficulties in compliance with fluid restriction.

Computerised analysis of the fetal heart rate and relation to acidaemia at delivery

OBJECTIVE

To identify the individual features of the computerised analysis of the cardiotocograph that relate to arterial pH and base deficit at delivery.

DESIGN

Retrospective observational study.

SETTING

Teaching hospital labour wards.

PARTICIPANTS

679 women requiring continuous intrapartum fetal monitoring.

METHODS

Fetal heart and uterine contraction data were obtained using the Nottingham Fetal ECG monitor. Fetal heart rate patterns for the last half-hour preceding delivery were analysed using a computer algorithm developed for intrapartum application. The significance of the areas under receiver operator characteristic curves were calculated.

MAIN OUTCOME MEASURES

Umbilical arterial pH and base deficit at delivery.

RESULTS

Three parameters, fetal bradycardia, total deceleration area and the deceleration area after a contraction had receiver operator characteristic curves that significantly predict a low umbilical arterial pH and base deficit at delivery (areas under receiver-operator characteristic curves = 0.53, SD 0.01 P = 0.03; 0.60, SD 0.03 P = 0.002; 0.62 SD 0.04 P < 0.001, respectively). Tachycardia, accelerations and variability did not.

CONCLUSIONS

The individual components of the computerised analysis of the fetal heart rate that predict acidaemia at delivery are identified.

Familial advanced sleep phase syndrome

BACKGROUND

The circadian rhythms of sleep propensity and melatonin secretion are regulated by a central circadian clock, the suprachiasmatic nucleus of the hypothalamus. The most common types of sleep disorders attributed to an alteration of the circadian clock system are the sleep/wake cycle phase disorders, such as delayed sleep phase syndrome and advanced sleep phase syndrome (ASPS). Advanced sleep phase syndrome is characterized by the complaint of persistent early evening sleep onset and early morning awakening. Although the complaint of awakening earlier than desired is relatively common, particularly in older adults, extreme advance of sleep phase is rare.

OBJECTIVE

To phenotypically characterize a familial case of ASPS.

METHODS

We identified a large family with ASPS; 32 members of this family gave informed consent to participate in this study. Measures of sleep onset and offset, dim light melatonin onset, the Horne-Ostberg morningness-eveningness questionnaire, and clinical interviews were used to characterize family members as affected or unaffected with ASPS.

RESULTS

Affected members rated themselves as "morning types" and had a significant advance in the phase of sleep onset (P<.001) and offset (P =.006) times. The mean sleep onset was 2121 hours for the affected family members and 0025 hours for the unaffected family members. The mean sleep offset was 0507 hours for the affected members and 0828 hours for the unaffected members. (Times are given in military form.) In addition, the phase of the circadian rhythm of melatonin onset for the affected family members was on average 3-1/2 hours earlier than for the unaffected members.

CONCLUSIONS

The ASPS trait segregates with an autosomal dominant mode of inheritance. The occurrence of familial ASPS indicates that human circadian rhythms, similar to those in animals, are under genetic regulation. Genetic analysis of familial sleep and circadian rhythm disorders is important for identifying a specific gene(s) responsible for the regulation of sleep and circadian rhythms in humans.

A pilot study on the effect of progressive muscle relaxation training of patients after stoma surgery

Eighteen patients who had undergone stoma surgery were assessed with respect to their anxiety level and self-reported quality of life (QoL) on three occasions; namely, immediately after surgery, 5 weeks after surgery, and 10 weeks after surgery. The patients were randomised into a control group (n = 10) and an experimental group (n = 8). A 20-min set of audiotaped instructions on progressive muscle relaxation training (PMRT) was given to the patients in the experimental group for home practice. Assessment instructions included the Chinese State-Trait Anxiety Inventory (C-STAI), the Quality of Life Index for Colostomy (QoL-Colostomy) and the Hong Kong Chinese version of the World Health Organisation Quality of Life Scale (WHOQoL). Results indicated that there was a significant decrease in both the C-STAI score (F = 4.66, P < 0.05) and the WHOQoL score (F = 4.74, P < 0.05) in the experimental group. Among the domains of WHOQoL, a significant difference was shown in physical health/independence and general perception of QoL, with the experimental group demonstrating better functioning. For the QoL-Colostomy, however, there was no significant difference between the control and experimental groups. The results suggest that the use of PMRT could enhance quality of life and decrease state anxiety in patients after stoma surgery.

Resonant tunneling into a biased fractional quantum Hall edge

We observe resonant tunneling into a voltage biased fractional quantum Hall effect (FQHE) edge, using atomically sharp tunnel barriers unique to cleaved-edge overgrown devices. The resonances demonstrate different tunnel couplings to the metallic lead and the FQHE edge. Weak coupling to the FQHE edge produces clear non-Fermi liquid behavior with a sixfold increase in resonance area under bias arising from the power law density of states at the FQHE edge. A simple device model uses the resonant tunneling formalism for chiral Luttinger liquids to successfully describe the data.

Dextran sedimentation in a semi-closed system for the clinical banking of umbilical cord blood

BACKGROUND

The results of current processing procedures for reducing volume and recovering HPCs from umbilical cord blood (UCB) before cryopreservation vary.

STUDY DESIGN AND METHODS

Dextran was added to bags containing UCB, followed by sedimentation for 30 minutes. The processed UCB was then frozen. RBCs, nucleated cells, MNCs, CD34+ cells, CFUs and long-term culture-initiating cells (LTC-ICs), viability, and sterility were evaluated. Fractionations in ficoll-hypaque and hydroxyethyl starch (HES) were also run in parallel for comparison.

RESULTS

The nucleated cell (NC) recovery and RBC depletion were 86.1 percent and 94.3 percent, respectively (n = 50). Sedimentation with dextran also enabled the recovery of 80.7 percent MNCs and 82.6 percent CD34+ cells (n = 30). Postsedimentation samples displayed no impairment of CFU growth (n = 42, 108.7% CFU-C, 104.6% CFU-GEMM, 107% CFU-GM, and 95.7% BFU-E). Long-term cultures on five paired samples before and after sedimentation generated similar numbers of CFU-C each week (p = 0.88). Limiting dilution analysis of 12 paired pre/postsedimentation samples showed comparable median proportions of LTC-ICs (1/6494 vs. 1/5236; p = 0.18). The cell viability of 24 samples of thawed UCB after sedimentation was 90.3 percent (77.5-96%) and the recovery of CFU-C, CFU-GEMM, CFU-GM, and BFU-E of 11 postsedimentation samples was 93.4 percent, 84.9 percent, 92.3 percent, and 83.4 percent, respectively. NC recovery was significantly higher after treatment with dextran than with ficoll-hypaque (n = 30; 88.5% vs. 29.1%; p<0.005) and HES treatment (n = 21; 88.5% vs. 76.4%; p = 0.004). However, MNCs, CD34+ cells, CFUs, LTC-ICs, and RBCs were comparable. Two cycles of dextran sedimentation recovered 93.9 percent of NCs with cell viability of 98.6 percent (96.5-100%), whereas 11.7 percent of RBCs were retained (n = 20). The final yield volume was 33.5 (28-41) mL.

CONCLUSION

In a semi-closed system, dextran sedimentation enabled volume reduction of UCB without significant quantitative and qualitative losses of HPCs.

Knowledge of and attitudes toward sex among Chinese adolescents

This study was conducted to examine the knowledge of and attitudes toward sex of 178 Chinese secondary school students in Hong Kong. The data were collected using a questionnaire that comprised three parts: the Chinese version of the Mathtech Knowledge Test, the Chinese version of the Mathtech Attitude and Value Scale, and a demographic sheet seeking sociodemographic information. In general, students demonstrated a low level of sexual knowledge, especially in relation to adolescent marriage, the probability of pregnancy, and adolescent sexual activity. With regard to attitudes, students indicated positive attitudes toward importance of family and importance of birth control. Male students in comparison with their female counterparts had a higher level of agreement with premarital intercourse and the use of pressure and force in sexual activity.

Metabolic capabilities of CYP2F2 with various pulmonary toxicants and its relative abundance in mouse lung subcompartments

The tissue- and species-selective toxicity of a number of pulmonary toxicants has been attributed to the presence and distribution of activating enzymes with high k(cat) in target airways of susceptible species. The mouse is especially sensitive to a variety of metabolically activated lung toxicants. Recombinant CYP2F2 (mouse) was recently shown to effectively metabolize the species-selective pulmonary toxicant naphthalene. Here we show that the pulmonary toxicants 1-nitronaphthalene and 2-methylnaphthalene are metabolized readily with high k(cat) values (17.1 and 67.6 min(-1), respectively) to potentially cytotoxic intermediates at biologically relevant K(m) values (21.5 and 3.7 microM, respectively). Additionally, anthracene and benzo[a]pyrene are both metabolized by CYP2F2 (0.14 +/- 0.04 and 0.04 +/- 0.00 nmol/nmol/min, respectively), albeit at much lower rates. The levels of total CYP in mouse airways are considerably higher than those in parenchyma and trachea, and this is consistent with much higher rates of naphthalene metabolism in microsomal preparations from airways compared with the other subcompartments. The data suggest that CYP2F2 is a prominent cytochrome P450 in mouse lung that metabolizes a number of pulmonary toxicants. The presence of CYP2F2 may be important in the susceptibility of the mouse to metabolically activated pulmonary toxicants.

Plateau Behavior in the Chiral Luttinger Liquid Exponent

The current-voltage power law exponent, alpha, for electron tunneling into chiral Luttinger liquids at the fractional quantum Hall edge is found to exhibit a plateaulike structure at alpha close to 3 as the filling factor, nu, is varied. The presence of a plateau near alpha = 3 strongly suggests a fundamental connection between alpha and the structure of the underlying quantum ground states associated with the robust incompressible nu = 1/3 Hall fluid. However, the position in the inverse filling factor where the plateau occurs can vary between samples and appears shifted to values higher than expected from theory.

Experience of palliative home care according to caregivers' and patients' ages in Hong Kong Chinese people

PURPOSE/OBJECTIVES

To identify the relationship between family caregivers' reported difficulty in managing caregiver tasks and ages of caregivers and patients.

DESIGN

Cross-sectional, descriptive survey.

SETTING

A hospice homecare program in Hong Kong.

SAMPLE

Twenty-nine Chinese family caregivers who had experienced at least weekly caregiving responsibility for more than two months and were able to read and understand Chinese.

METHODS

Respondents completed a caregiver task inventory. Four homecare nurses assisted in the distribution and collection of questionnaires.

MAIN RESEARCH VARIABLES

Caregiver tasks and age and patient age.

FINDINGS

Caregivers' age was negatively correlated with reported difficulty in overall tasks and in interpersonal ties. The patients' age was negatively correlated with reported difficulty in direct care to patients, intrapersonal tasks, and overall tasks.

CONCLUSIONS

The younger the caregiver, the more difficulty he or she experienced in the caregiving role, particularly in the maintenance of social and family ties. Caregivers of younger patients experienced more difficulty in most aspects of caregiving tasks. More research with a larger sample size is required to fully investigate the effect of age on the family caregiving experience and the validity of the caregiver task inventory.

IMPLICATIONS FOR NURSING PRACTICE

Nursing support and preparation to younger caregivers and caregivers of younger patients are suggested in the practice of palliative home care.

MTAP gene deletion in endometrial cancer

A gene (MTAP) that encodes the enzyme 5'-deoxy-5'-methylthioadenosine (MTA) phosphorylase has been identified on chromosome 9p21 and cloned. The substrate of this enzyme, MTA, inhibits aminopropyltransferases that synthesize polyamines from putrescine and decarboxylated S-adenosylmethionine. This enzyme normally cleaves MTA to adenine and 5'-methylthioribose-1-phosphate, which are recycled to adenine nucleotides and methionine, respectively. Cancers with deletions of the MTAP gene may be especially susceptible to chemotherapeutic regimes which interfere with purine or methionine utilization. The purpose of this study was to determine deletion of the MTAP gene in endometrial cancer using a polymerase chain reaction-based method. Therefore, 50 endometrial adenocarcinomas were studied. Partial or total deletions of the MTAP gene were detected in 7 (14%) of these cancers. There were no significant relationships between gene deletion and patient age, pathological grade or clinical stage (p > 0.05). The findings indicate that deletion of the MTAP gene does occur in a subgroup of endometrial cancer. The present work may be extended to the development of molecular diagnosis of MTAP gene deletion in other cancers and assist in selecting appropriate chemotherapy.

Evaluation of the accuracy of transvaginal sonography for the assessment of retained products of conception after spontaneous abortion

Transvaginal sonography (TVS) was used to assess uterine contents in 100 consecutive subjects presenting with a diagnosis of spontaneous abortion. TVS assessments were correlated with findings at subsequent evacuation of retained products of conception (ERPC). There was a strong correlation between the weight of the surgical specimen at ERPC with both the sagittal (r = 0.76; p < 0.05) and transverse (r = 0.73; p < 0.05) plane area measurements of the uterine cavity. Combining the 2 sonographic measurements increased the correlation to r = 0.81 (p < 0.05). Fifteen of 25 subjects who had been categorised to have an 'empty' uterus had less than 5 g of tissue removed and the other 10 subjects less than 10 g of tissue. In 20 of these 25 cases, the surgeon described the amount of curettings as 'small or non-significant'. TVS can accurately identify those women who do not have a significant amount of residual uterine tissue following spontaneous abortion.

Quantitative analysis of the bidirectional fetomaternal transfer of nucleated cells and plasma DNA

BACKGROUND

Recently, much interest has been generated on the fetomaternal transfer of nucleated cells and plasma DNA. However, there has been no systematic quantitative comparison of these two directions and two modalities of trafficking within the same study population.

METHODS

The fetus-to-mother transfer of nucleated cells and plasma DNA in pregnant women carrying male babies was studied using a real-time quantitative PCR assay for the S:RY gene. For mother-to-fetus transfer, real-time quantitative PCR assays for the insertion/deletion polymorphisms involving the glutathione S:-transferase M1 and angiotensin-converting enzyme genes were used.

RESULTS

Of the 50 informative mother-baby pairs, maternal DNA was detected in the cellular fraction of umbilical cord blood in 24% of cases (12 of 50), at a median fractional concentration of 2.6 x 10(-4) (interquartile range, 1.7 x 10(-4) to 3.6 x 10(-4)). In the plasma fraction of cord blood, maternal DNA was detected in 30% (15 of 50) of cases at a median fractional concentration of 3 x 10(-3) (interquartile range, 1 x 10(-3) to 1.6 x 10(-2)). For the other direction of trafficking, fetus-to-mother transfer of nucleated cells was detected in 26% of cases (13 of 50) at a median fractional concentration of 3.2 x 10(-4) (interquartile range, 0.6 x 10(-4) to 7.6 x 10(-4)). In the plasma fraction, fetal DNA was detected in 100% of maternal plasma (50 of 50) at a median fractional concentration of 3 x 10(-2) (interquartile range, 1.4 x 10(-2) to 5. 3 x 10(-2)).

CONCLUSIONS

This study indicated that significantly more fetal DNA is present in the plasma of pregnant women compared with DNA from the cellular fraction of maternal blood. In addition, maternal DNA was demonstrated in both the cellular and plasma fractions of cord blood after delivery. This study has therefore determined the fundamental quantitative values for the bidirectional fetomaternal cellular and plasma DNA traffic.

p53 polymorphism and human papillomavirus infection in Hong Kong women with cervical cancer

In this study we investigated the involvement of p53 polymorphism at codon 72, the infection and typing of human papillomavirus (HPV) and the correlation of p53 polymorphism with HPV type and other clinicopathologic characteristics in 72 Hong Kong women with cervical cancer. We developed a simple and nonradioactive method for determining polymorphism at codon 72 of the p53 gene. The homozygous p53 arginine allele (Arg/Arg) was detected in 22 (31%), the homozygous p53 proline allele (Pro/Pro) in 14 (19%) and the heterozygous allele (Arg/Pro) in 36 (50%) cases, respectively. Using the consensus primers MY11 and MY09, HPV infection was detected in 55 of 72 (76%) cases. The prevalent types were HPV-16 (55%), HPV-18 (16%) and HPV-58 (9%). The number of HPV-positive cases with Arg/Arg, Pro/Pro and Arg/Pro were 17 (31%), 12 (22%) and 26 (47%), respectively. The p53 polymorphism at codon 72 was not significantly correlated with any of the HPV types (p > 0.05). No striking overrepresentation of homozygous arginine-72 p53 was observed in HPV-associated cervical cancer. The results in this study did not show that any p53 polymorphic form has a prognostic significance for cervical cancer.

Disposition towards critical thinking: a study of Chinese undergraduate nursing students

The purpose of this study was to explore empirically whether undergraduate nursing students at a selected university in Hong Kong display a disposition towards critical thinking. The California Critical Thinking Dispositions Inventory (CCTDI) was used to measure the key theoretical aspects of the overall dispositional dimension of critical thinking. A cross-sectional descriptive design was used to examine 122 Chinese students who were completing their 1st, 2nd and 3rd year of a university baccalaureate nursing programme. In the majority of sub-scales of CCTDI, students showed a negative disposition towards critical thinking. A one-way ANOVA indicated that year 3 students scored significantly lower than their junior counterparts (P < 0. 001). Pearson product moment correlation coefficient yielded a significant positive relationship between critical thinking dispositions and term grade point average (P < 0.05). Consistent with the findings of western studies, the students scored lowest on the truth-seeking sub-scale and highest on the inquisitiveness. Discussion of the findings with regard to nursing education, curriculum and research is delineated.

Locomotor response to an open field during C57BL/6J active and inactive phases: differences dependent on conditions of illumination

Time of day has proven to be a source of variability in diverse behavioral measures. Knowledge of the pattern of this temporal effect as well as its origin (exogenous or endogenous) is essential for a precise description of any behavior. This study analyzed the effect of the external light-dark cycle and the internal rest-activity rhythm on the response of C57BL/6J mice to a novel environment. In a first experiment, animals maintained in a 12:12-h light-dark cycle were tested in an open field at six different times of day. A diurnal rhythm of ambulation in the open field was observed with greater levels of activity exhibited by those groups tested at night. Long-term and short-term behavioral habituation to spatial novelty were also affected by phase of the light-dark cycle. A second experiment was designed to control for any direct effect of the light-dark cycle by keeping the animals in dim green light where entrainment was maintained by a skeleton photoperiod (two 15-min bright-light pulses separated by 12 hours of green, dim light). This second group of animals was tested at two different circadian phases under the same conditions of illumination. One group was tested during the subjective night and another group during the subjective day, i.e., 2 or 14 h after the onset of the active phase, as assessed by wheel-running behavior. No effect of circadian phase on ambulation or habituation of this response to the open field was observed in these animals. Taken together, these results suggest that spatial novelty is equally arousing regardless of circadian phase and that the conditions of illumination can dramatically alter the response to a novel environment.

Development of a customised birthweight standard for ethnic Chinese subjects

A model to establish customised birthweight standards for the Chinese population was developed, using data from a cohort of 1564 Chinese women with normal singleton pregnancies. Multiple regression analysis was performed using maternal height, weight, parity, gestation at delivery and fetal sex as independent (predictor) variables. From this, a customised ideal birthweight for each baby can be estimated, and the normality of the actual birthweight can be evaluated according to this, rather than from population standards. The results of this study show that birthweights are strongly influenced by maternal characteristics, confirming conclusions from similar studies in other ethnic populations. The overall mean birthweight at 280 days of gestation was 3252 g, which was smaller than that of the Caucasian population. Birthweight increased with maternal height (5.1 g/cm), maternal booking weight (10.2 g/kg) and gestation at delivery (18.3 g/day from 280 days). Babies from women who had two previous deliveries weighed 145.2 g more than the nulliparous. Male babies were 84.8 g heavier than females. Adjustment using these results produces a customised ideal birthweight for each baby. When compared with population based standards, customised birthweight standards identified significantly fewer small for gestational age (SGA - birthweight below 10th centile, McNemar Chi square = 19.1, p < 0.01) and fewer large for gestational age (LGA - birthweight above 90th centile, McNemar Chi square = 23.7, p < 0.01) cases.

Effects of an educational programme on adolescents with premenstrual syndrome

An education program was developed and evaluated to determine its efficacy in increasing knowledge and decreasing the severity of symptoms of premenstrual syndrome (PMS). Participants from a sample of 94 schoolgirls aged between 14 and 18 years from four secondary schools in Hong Kong were assigned to either the experimental or control group. Immediately following the education program, the schoolgirls in the experimental group had significantly increased knowledge scores as measured by the Premenstrual Syndrome Knowledge Questionnaire. Three months following the education program, schoolgirls in the experimental group reported having a significant reduction in total PMS scores and three of the subscale scores as measured by a translated version of Abraham's Menstrual Symptom Questionnaire. In addition, no significant differences were found for the control group on pre-test and post-test PMS scores suggesting that the education program could have been the source of the reduction in PMS symptoms of the experimental group of young adolescents girls.

Increased fetal DNA concentrations in the plasma of pregnant women carrying fetuses with trisomy 21

BACKGROUND

The recent discovery of the presence of circulating cell-free fetal DNA in maternal plasma opens up new prenatal diagnostic applications and provides new avenues for clinical investigation. It is of research and potential diagnostic interest to determine whether fetal trisomy 21 may be associated with quantitative abnormalities of circulating fetal DNA in maternal plasma.

METHODS

Maternal plasma samples were prospectively collected from two centers situated in Hong Kong and Boston. Samples collected from Boston consisted of 7 women carrying male trisomy 21 fetuses, 19 carrying euploid male fetuses, and 13 carrying female fetuses. Samples collected from Hong Kong consisted of 6 women carrying male trisomy 21 fetuses, 18 carrying euploid male fetuses, and 10 carrying female fetuses. Male fetal DNA in maternal plasma was measured using real-time quantitative Y-chromosomal PCR.

RESULTS

For patients recruited from Boston, the median circulating fetal DNA concentrations in women carrying trisomy 21 and euploid male fetuses were 46.0 genome-equivalents/mL and 23.3 genome-equivalents/mL, respectively (P = 0.028). For patients recruited from Hong Kong, the median circulating fetal DNA concentrations in women carrying trisomy 21 and euploid male fetuses were 48.2 genome-equivalents/mL and 16.3 genome-equivalents/mL, respectively (P = 0.026). None of the samples from women carrying female fetuses had detectable Y-chromosomal signals.

CONCLUSIONS

Abnormally high concentrations of circulating fetal DNA are found in a proportion of women carrying fetuses with trisomy 21. The robustness and reproducibility of real-time PCR analysis of maternal plasma makes it a valuable tool for cross-institutional collaboration involving centers located in different parts of the world.

Elevated mid-trimester maternal corticotrophin-releasing hormone levels in pregnancies that delivered before 34 weeks

OBJECTIVE

To test whether maternal corticotrophin-releasing hormone levels are elevated in the mid- trimester for those women who subsequently had spontaneous preterm delivery and to assess the clinical utility of the measurement in the prediction of preterm delivery.

DESIGN

A prospective observational study.

SETTING

Department of Obstetrics and Gynaecology, Prince of Wales Hospital, Hong Kong.

POPULATION

1047 low risk pregnant women recruited at 15-20 weeks of gestation.

METHODS

Venous samples were assayed for levels of corticotrophin-releasing hormone. The investigators responsible for the laboratory assay were blinded to the obstetric outcome.

MAIN OUTCOME MEASURES

Incidence of preterm, term and post-term pregnancies.

RESULTS

Those who were delivered spontaneously at a preterm gestational age (before 34 weeks) had significantly higher corticotrophin-releasing hormone levels in the mid-trimester, compared with those who were delivered at term or post-term. There was a trend towards lower corticotrophin-releasing hormone levels with more advanced gestational age at delivery. When the measurement of corticotrophin- releasing hormone was used to predict delivery before 34 weeks, the best cut off was 1.9 MoM, which produced a sensitivity of 72.7% and specificity of 78.4%. This translated to a positive predictive value of 3.6%, negative predictive value of 99.6% and relative risk of 9.4 when the background prevalence of spontaneous preterm delivery before 34 weeks was 1.1%. The likelihood ratio was 3.4.

CONCLUSIONS

Mid-trimester maternal corticotrophin-releasing hormone levels are elevated in pregnancies destined to deliver preterm before 34 weeks. When used alone in a low risk population, the measurement has a low predictive power for preterm delivery. However, the likelihood ratio of 3 4 implies that in high risk populations the test may be considerably more valuable.

Clinical use of serum c-erbB-2 in patients with ovarian masses

The c-erbB-2 (Her-2/neu) gene product has a large extracellular domain (ECD) and part of which could be identified in the serum. We measured the serum level of c-erbB-2 ECD in 93 patients, who presented with ovarian masses, with an enzyme immunoassay test and an elevated level was found in 5.5, 16.7 and 38% of patients with benign, borderline and malignant ovarian neoplasms, respectively. This serum marker may reflect the overexpression of c-erbB-2 gene in tumor tissues, which is associated with poor prognosis. However, measurement of c-erbB-2 ECD when used alone or in combination with CA 125 is not useful in differentiating benign from malignant ovarian tumors.