Study protocol for a comparative randomized controlled trial of Tai Chi and conventional exercise training on alleviating depression in older insomniacs

Background

Insomnia and depression are prevalent mental disorders that are often comorbid among older adults. Lifestyle intervention strategies incorporating Tai Chi or conventional exercise have been shown to alleviate symptoms of insomnia and depression. However, the comparative efficacy of these exercise modalities in individuals with both disorders has yet to be determined. Therefore, the aim of this study is to examine the efficacy of Tai Chi and conventional exercise for reducing depressive symptoms in older adults with chronic insomnia and depressive symptoms, when compared to a health education control.

Methods

This study is a prospective, assessor-blinded, three-arm, parallel group, randomized controlled trial. Older adults aged ≥60 years with a diagnosis of chronic insomnia and depressive symptoms will be randomly assigned to a Tai Chi, conventional exercise or health education control condition on a 1:1:1 basis. Interventions will last for 3 months, with a 6-month follow-up period. The primary outcome is depressive symptoms, assessed using the Hospital Anxiety and Depression Scale. Secondary outcomes include subjective sleep quality, 7-day actigraphy, 7-day sleep diary, anxiety symptoms, quality of life, medication usage and physical function. All measurements will be conducted at baseline, 3 months and 9 months by outcome assessors who are blinded to group allocation.

Discussion

This study will compare the efficacy of Tai Chi and conventional exercise in improving depression outcomes in older adults with chronic insomnia and depressive symptoms. Our results will shed light on the clinical potential of these interventions for combating insomnia and depression in older adults.

Significant others and students' leisure-time physical activity intention: A prospective test of the social influence in sport model

This two-wave prospective study applied the Social Influence in Sport Model to investigate whether the social influences of parents, physical education (PE) teachers, and peers were predictive of students' intention to engage in leisure-time physical activity (PA). Participants were 2,484 secondary school students (11-18 years old) who completed a questionnaire assessing positive influence, punishment, and dysfunction from the three social agents (parents, PE teachers, and peers) at baseline, and PA intention at a 1-month follow-up. Structural equation modelling (SEM) yielded excellent goodness-of-fit and consistent pathways between the three social agents. Students' leisure-time PA intention (R² = .103 to 0.112) was positively associated with positive influence (β = .223 to 0.236, p < .001) and punishment (β = .214 to 0.256, p < .01), and negatively associated with dysfunction (β = - 0.281 to -.335, p < .001). Multi-group SEM showed that the predictions were invariant between parents, PE teachers, and peers. Furthermore, no significant differences in students' gender were found between perceived social influence and PA intention. The findings supported the application of the Social Influence in Sport Model in explaining the role of significant others on students' intention to take part in leisure-time PA.

Surgical outcomes and sleep endoscopy for children with sleep-disordered breathing and hypotonia

OBJECTIVE

To study the efficacy of surgical management for obstructive sleep apnea (OSA) syndrome in children with hypotonia, and to identify common anatomic sites of airway obstruction.

METHODS

Retrospective chart review of polysomnographic parameters and quality of life instrument scores for seventy eight children with hypotonia who underwent surgical intervention for sleep-disordered breathing at two tertiary children's hospitals, and analysis of drug-induced sleep endoscopy data using a previously validated scoring system.

RESULTS

Children undergoing surgical intervention had baseline severe OSA with a statistically significant improvement in apnea-hypopnea index from 23.6 to 11.1 after surgery, but persistent severe OSA. OSA-18 sleep-related quality of life measurement and overall quality of life score showed statistically and clinically significant improvements, from 72.0 to 43.4 and from 5.3 to 7.6 respectively. Sleep endoscopy showed an average obstructive score of 7.2/15 (n = 39), with multi-level obstruction in 49% of children. Greater than 50% obstruction was observed at the tongue base in 64% of patients, velum in 46%, lateral pharyngeal wall in 38%, supraglottis in 38%, and adenoid in 23%.

CONCLUSION

OSA syndrome is challenging to treat in hypotonic children. Severe residual OSA is common after surgical intervention, but improvement in quality of life is clinically and statistically significant. The tongue base is the most common site of persistent airway obstruction. Drug-induced sleep endoscopy can identify sites of airway obstruction and may aid in surgical planning for high-risk patients.

A palliative care approach to end-stage neurodegenerative conditions

INTRODUCTION

Neurodegenerative conditions, such as Alzheimer's disease, Parkinson's disease and motor neurone disease, are progressive and incurable conditions that ultimately lead to a state of total functional incapacitation and death. These conditions are "terminal" and, therefore, should be managed with a palliative care approach. This article highlights some of the issues in caring for patients with end-stage neurodegenerative conditions from a palliative perspective.

METHODS

This review is based on evidence from pre-existing medical literature on the above subject and the authors' personal experiences and observations.

CONCLUSION

Patients with end-stage neurodegenerative conditions have needs similar to that of advanced cancer patients. Therefore, the principles and practice of palliative care should be applied to such patients. This may also mean that palliative care training should be undertaken in nursing homes, where a large number of such patients are located.

Parkinson disease and its differentials. Diagnoses made easy

BACKGROUND

Parkinson disease is a common neurological disorder that is both underdiagnosed and inaccurately diagnosed. There is no reliable biological marker or test that can differentiate between causes of parkinsonism. Even for experienced clinicians, the clinical diagnostic accuracy compared to post mortem findings is about 80%.

OBJECTIVE

To discuss the clinical features that differentiate Parkinson disease from other important causes of parkinsonism.

DISCUSSION

Although Parkinson disease is a common cause of parkinsonism, other candidates such as drug reactions, benign essential tremor, vascular disease and Lewy body dementia need to be differentiated. Incorrect diagnosis can result in complications related particularly to the use of levodopa and antipsychotic agents. Diagnostic accuracy is important to ensure appropriate management, to avoid complications and to assist patients to have realistic expectations and prognostic information about their condition.

Pilot study of prevalence of Parkinson's disease in Australia

Parkinson's disease is a common neurological disease and its prevalence increases with age. Because of an ageing population and changing environment compared to the last epidemiological study done in Australia over 30 years ago, we have conducted a door-to-door pilot survey which looked at the latest prevalence as well as putative risk factors in a random population. We used a two-phase investigation method (screening followed by detailed examination) in a random community sample of 2,820 households (with 527 individuals aged 55 and over) along with 203 residents in aged care facilities (single-phase examination for residents aged 55 and above) in the Randwick area of Sydney, New South Wales. We had a 75% participation rate in the community and a 94% in the aged care facilities. The results of the survey in this sample of 730 subjects indicated that the crude prevalence of Parkinson's disease was between 3.6 and 4.9% (higher in the aged care facilities). The putative risk factors positively identified using chi-square method were 'family history' (p < 0.01) and 'exposure to chemicals at work or in surrounding environment' (p < 0.05). The age-adjusted prevalence rate of Parkinson's disease revealed at least a 42.5% increase in the disease compared to 1966. We conclude that there may be an increase in the disease in Australia due to ageing and other risk factors.

Enteral nutrition of the very low birth weight (VLBW) infant

INTRODUCTION

Optimal nutrition is critical in the management of the very low birth weight (VLBW) infant.

METHODS

The type of feeding, initiation, route and schedule of feeding, and the rate of increase in feeding volume were reviewed.

RESULTS

Human milk from the preterm infant's mother is the feeding of choice. When full enteral feeding is established, supplementation of human milk with a multi-nutrient fortifier is required. In VLBW infants having poor weight gain when exclusively fed human milk, feeding of hindmilk is encouraged if the mother expresses large quantities of breast milk. Lactation support is vital for the mother, including appropriate methods of milk collection, storage and transport to the nursery. In mothers who produce no or insufficient human milk, preterm formulas are an alternative feeding, used either alone or in conjunction with human milk. Minimal enteral nutrition using sub-nutritional feedings in the first week of life is advantageous. Intragastric intermittent ("bolus") tube feeding is the route of choice for the infant born at < 32 to 34 weeks gestational age. Feeding volume must be advanced cautiously at < 20 mL/kg/day.

CONCLUSION

Future goals of nutrition research in the VLBW infant must include determining the role and optimal composition of the various nutrients and duration of use.

Effects of cortisol on chloride cells in the gill epithelium of Japanese eel, Anguilla japonica

The purpose of the present study was to determine the effects of cortisol on the development of the freshwater chloride cell (CC), using flow cytometry. Scanning electron microscopy was used to determine the corresponding modifications in CC apical structure. Simultaneously, biochemical analyses were conducted to determine the activities of transport ATPases, mitochondrial enzymes (succinate dehydrogenase (SDH) and Mg(2+)-ATPase) and lactate dehydrogenase (Ldh). The effects of daily i.m. injection of 2 microg/g cortisol were compared with sham-injected freshwater-, control freshwater- and seawater-adapted fish. The hormone did not affect the activities of Ca(2+)-ATPases in CCs. However, it stimulated the proliferation and differentiation of the two freshwater CC subtypes (F1, 66+/-2.18% (s.e.m. ) and F2, 34+/-2.18%), in which the relative proportion of F1 CCs was transiently reduced in the first 5 days of treatment (F1, 53+/-1.83%; F2, 47+/-1.83%) but was then restored to a higher relative percentage on day 10 (F1, 70+/-1.42%; F2, 30+/-1.42%). Biochemically, it induced the activities of Na(+)/K(+)-ATPase, Mg(2+)-ATPase, SDH and Ldh, suggesting an increase in ion pumping and its associated metabolic activities. CCs from cortisoltreated fish demonstrated recessed apical morphology, accompanied by an increase in cell density (2012 to 2413/mm(2)). Nevertheless, the extent of cell proliferation and differentiation and the biochemical changes were significantly lower than those of seawater fish. Our results indicate that cortisol alone cannot stimulate a complete differentiation of freshwater CCs to seawater CCs. However, the respective roles of the two CC subtypes in freshwater and seawater environments are indicated.

Intention and responsibility in double effect cases

I argue that the moral distinction in double effect cases rests on a difference not in intention as traditionally stated in the Doctrine of Double Effect (DDE), but in desire. The traditional DDE has difficulty ensuring that an agent intends the bad effect just in those cases where what he does is morally objectionable. I show firstly that the mental state of a rational agent who is certain that a side-effect will occur satisfies Bratman's criteria for intending that effect. I then clarify the nature of the moral distinction in double effect cases and how it can be used to evaluate the moral blameworthiness of agents rather than the moral status of the acts. The agent's blameworthiness is reduced not by his lack of intention but by his desire not to bring about the side-effect, and the 'counterfactual test' can be used to determine whether he desires the effect in acting. In my version, the DDE has its rationale in virtue ethics; it is not liable to abuse as the traditional version is; and it makes more plausible distinctions when applied to standard examples.

A comparison of polymorphism in the 3'-untranslated region of the prothrombin gene between Chinese and Caucasians in Australia

The 20210G-->A mutation in the 3'-untranslated (UT) region of the prothrombin gene is extremely rare or absent in the Chinese population (0 in 449 subjects, 140 with a history of thromboembolism). This is in contrast to the results from 302 Caucasians from Australia in our study (4.6% in 153 patients with a thromboembolic history and 1.3% in 149 patients with no history). This rarity implies that the variant of the prothrombin gene is probably not the main cause of venous thromboembolism in the Chinese population. Even among Caucasians this mutation accounts for only a minor percentage of all patients with thromboembolism. The relatively low incidence of venous thromboembolism in the Chinese population compared with Caucasians is probably as a result of the low prevalence of factor V Leiden or other environmental or genetic factors.

Validating a screening questionnaire for parkinsonism in Australia

Parkinson's disease is a common neurodegenerative disorder in elderly people. Epidemiological studies of the disease can be labour intensive. A two phase design including a screening questionnaire as the first phase has become a popular method in prevalence studies of Parkinson's disease. Such a design has many advantages including less work for assessing physicians and enhanced recruitment of people to be screened. However, its wider application may be questioned because validation has been limited to samples that are drawn from hospitals (or clinics) and may be inappropriate for a community setting. This study assesses whether validating screening questionnaire by using a hospital sample yields the same result as a community based sample. Furthermore, it seeks to establish whether the screening instrument can be simplified to involve less questions. The findings show that some of the questions used in the screening phase yield different responses when comparing a hospital group with a community group. This study also provides a simplified model of questions that may be relevant for screening in the community setting.

The alpha-synuclein gene and Parkinson disease in a Chinese population

OBJECTIVE

To study the Ala53Thr and Ala30Pro mutations of the alpha-synuclein gene in a large number of Chinese patients with Parkinson disease (PD) as well as controls.

METHODS

We recruited 183 Chinese patients with sporadic PD, 17 with younger-onset PD (onset age <50 years), and 7 with PD and a positive family history as well as 227 unaffected Chinese control subjects from the outpatient departments of 2 major hospitals in Hong Kong. All subjects were assessed for the the diagnosis of PD by a consultant neurologist or geriatrician. Subjects were interviewed with a standard questionnaire that also questioned for family history. Venous blood samples were obtained from the subjects and genomic DNA was extracted and studied for the presence of Ala53Thr mutation in exon 4 and Ala30Pro mutation in exon 3 of the alpha-synuclein gene using a polymerase chain reaction restriction fragment length polymorphism method.

RESULTS

None of the Chinese PD patients or controls had either the Ala53Thr (exon 4) or Ala30Pro (exon 3) mutation of the alpha-synuclein gene.

CONCLUSION

We failed to discover Ala53Thr or Ala30Pro mutations in a large number of Chinese patients with PD and control subjects, adding to the emerging consensus that variations in the alpha-synuclein gene are associated with PD in few families worldwide.

Effectiveness and acceptability of a newly designed hip protector: a pilot study

Hip fracture has a significant economic and personal cost, involving hospital admission and functional impairment for elderly people. To assess the benefit of using a newly designed hip protector (new material and new design) to prevent fracture in a realistic setting, a randomised intervention-control design was used to trial the effectiveness of pads worn by high falls risk residents (n=71) in nursing home for 9 months. 40 residents were in the intervention group and 31 were in the control group. A profile of falls, including time of day, and orientation was obtained to demonstrate the potential effectiveness of the protectors for injury prevention. Acceptance of the hip protector was also surveyed amongst nursing home staff and residents. One hundred and one falls and six fractures occurred in the control group. In contrast, one hundred and ninety one falls and three fractures occurred in the hip protector (pads) group. The three fractures in the protector wearing group occurred when pads were not in place. This was extrapolated as 1 in every 16.8 falls and 1 in every 63.7 falls resulting in fracture in the two groups, respectively. The relative risk of fracture was 0.264 (95% CI=0.073-0.959) when the fracture incidence rate in the intervention group (three fractures per 191 falls) was compared to the control group (six fractures per 101 falls). This is a statistically significant result and implies that this newly designed hip protector is effective in preventing hip fracture. The majority of falls occurred during the day, which was when protectors were worn in this study, but the data on orientation was incomplete, with direction unknown in 74% of falls. Compliance was an issue, which was interpreted as only 50.3% of falls recorded with protectors in place. Dementia was identified as the explanation for this as the pads were often removed by these residents who comprised the majority of participants. Perception of low risk was the primary barrier to residents accepting the intervention. Comfort of protectors was not a significant concern for staff or residents, and only staff described appearance as an issue. In conclusion, the newly designed hip protector is protective against fractures in a realistic setting. Compliance and acceptance of the protectors will ultimately determine the viability of this prophylaxis.

Vitamin E status of infants at birth

Preterm infants may be susceptible to chronic lung disease and retinopathy of prematurity because of deficient antioxidant mechanisms including deficiency of vitamin E. The aim of this study was to evaluate the status of the antioxidant vitamin E among preterm and term livebirths. Umbilical cord blood samples collected from 40 preterm and 180 term babies were analyzed for vitamin E levels using high performance liquid chromatography. Linear regression analysis was used to examine the relationship of vitamin E with gestational age, birth weight and appropriateness of weight for gestational age. The median vitamin E level of preterm babies (2.61 mg/L) was not significantly different from that of term babies (2.77 mg/L), p = 0.2. Linear regression analysis demonstrated a weak but statistically significant correlation between cord blood vitamin E levels and gestational age (r = 0.14, p = 0.046). Vitamin E levels did not correlate with birth weight or weight for gestational age. Preterm babies had a higher incidence of vitamin E deficiency compared to term babies (38% v 19%, p = 0.02). Our findings lead us to conclude that vitamin E accumulates in the fetus throughout the third trimester so that preterm infants are likely to have vitamin E deficiency.

The monoamine oxidase B gene GT repeat polymorphism and Parkinson's disease in a Chinese population

Monoamine oxidase B (MAOB) metabolises dopamine and activates neurotoxins known to induce parkinsonism in humans and primates. Therefore the MAOB gene (MAOB; Xp15.21-4) is a candidate gene for Parkinson's disease (PD). Longer length dinucleotide repeat sequences in a highly polymorphic GT repeat region of intron 2 of this gene showed an association with PD in an Australian cohort. We repeated this allele-association study in a population of 176 Chinese PD patients (90 men, 86 women) and 203 agematched controls (99 men, 104 women). Genomic DNA was extracted from venous blood and the polymerase chain reaction was used to amplify the appropriate regions of the MAOB gene. The length of each (GT) repeat sequence was determined by 5% polyacrylamide denaturing gel electrophoresis. There was no significant difference in allele frequencies of the (GT) repeat allelic variation between patients and controls (chi2 = 2.48; df = 5, P<0.75). Therefore the longer length GT repeat alleles are not associated with PD in this Chinese population. Possible reasons for the discrepancy between Chinese and Australian populations include a different interaction between this genetic factor and environmental factors in the two populations and the possibility that the long length GT repeat alleles may represent a marker mutation, genetically linked to another susceptibility allele in whites but not in Chinese. Methodological differences in the ascertainment of cases and controls in this cohort could also explain the observed differences. Further study is required to determine whether the longer length GT repeat alleles are true susceptibility alleles in PD.

The potential impact of home telecare on clinical practice

Home telecare, in which the health status of patients at home is monitored remotely, has the potential to improve care and reduce costs. Its widespread implementation would require fundamental changes in the healthcare system.

Chloride cell subtypes in the gill epithelium of Japanese eel Anguilla japonica

The purpose of the present study was to characterize chloride cell subtypes in the fish gill and to monitor the kinetic change of cell division in the gill epithelia during seawater adaptation. Employing a three-step Percoll gradient method, the gill chloride cells and nonchloride cell population were isolated. The isolated cells were studied using multiparameter flow cytometry, recording the changes in 1) cell size, 2) cellular granularity, and 3) cell autofluorescence. Two chloride cell subtypes were identified in the freshwater eels. Within 2-4 days after entering seawater, new subtypes of transitory chloride cell, with bigger cell size and more intense mitochondria autofluorescence, appeared. After full adaptation, two major seawater chloride cell subtypes were again discerned; their sizes were the largest and their mitochondria autofluorescence was the highest. In the second part of the experiment, cell cycle analysis demonstrated a progressive increase in the percentage of gill cells entering the DNA synthesis phase during seawater adaptation, where a small population of mitotic cells was identified in the nonchloride cell population but not in chloride cells. We hypothesize that the mitotic cells identified are stem cells, which will ultimately differentiate into seawater chloride cells. Our results confirm the existence of heterogeneity of chloride cells. Individual subtypes could be isolated in high purity for further studies to elucidate their respective function in mediating ion transport.

Isolation of viable cell types from the gill epithelium of Japanese eel Anguilla japonica

High-purity viable cells with low mitochondria (pavement cells) and mitochondria-rich content (chloride cells) were successfully isolated from the gill epithelium of Japanese eels, using three-step Percoll gradient low-speed centrifugation. Cytochemistry (silver staining for chloride, rhodamine-123, and Mitotracker for mitochondria and actin/spectrin immunofluorescence) and scanning electron microscope images were used to identify the cell types in the gill epithelium of the eel. Pavement cells were isolated at 97 and 98% purity for freshwater- and seawater-adapted eels, respectively, and chloride cells were obtained at 89 and 92% purity. The enzymatic activities of the isolated cells were determined. Na+-K+-ATPase, Mg2+-ATPase, and succinate dehydrogenase were found mainly in the chloride cell. Alkaline Ca2+-ATPase and low- and high-affinity Ca2+-ATPase were about twice as high in the chloride cell compared with the pavement cell. Transfer of eels to seawater resulted in enlargement of chloride cell sizes and significant increases in Na+-K+-ATPase, Mg2+-ATPase, and succinate dehydrogenase activities, while all Ca2+-ATPases declined by approximately 60-80%. This is the first report demonstrating the successful isolation of freshwater chloride cells and also an exclusive method of getting high-purity seawater chloride cells. The isolated cells are viable and suitable for further cytological and molecular studies to elucidate the mechanisms of ionic transport.

Genetic and environmental risk factors for Parkinson's disease in a Chinese population

An epidemiological study of the environmental and genetic factors as well as the possible interplay between them was conducted among 215 patients with Parkinson's disease and 313 controls in a Chinese population in Hong Kong. In univariate analysis, a regular tea drinking habit was found to be a protective factor, which had not been reported before. Smoking (a protective factor), family history, duration of pesticide exposure (in years) in farming and pesticide exposure during farming in women (both risk factors) have been reported previously. In multivariate analysis, current smoking reached borderline significance at the 5% level and the variables, years exposed to pesticides and family history were significant at the 10% level. By contrast with the common occurrence of polymorphism of the CYP2D6 gene (a gene involved with xenobiotic metabolism) in white people, it is very rare in China and is not thought to be a significant factor contributing to Parkinson's disease in Chinese people.

Congenital sodium diarrhoea in an Indian girl

We report the case of a newborn Indian girl with congenital sodium diarrhoea (CSD) who presented typically in utero, in whom diagnosis was made from markedly raised stool sodium in the presence of an alkaline stool. Treatment with sodium citrate normalised her metabolic and electrolyte status but resulted in transient uremia necessitating supplementation with sodium bicarbonate instead. She died at 11 weeks old following re-admission in a moribund state with grossly increased abdominal distension. Her fatal outcome in infancy suggests that CSD has a wide spectrum of clinical severity.

Usefulness of C-reactive protein in the diagnosis of neonatal sepsis

AIM

Early diagnosis of sepsis in the neonate is often difficult because symptoms and signs are usually non-specific. A study was conducted to evaluate C-reactive protein (CRP) as a screening tool for neonatal sepsis among very low birth weight (VLBW) infants.

METHODS

The study population consisted of 70 VLBW infants suspected of sepsis. Sepsis was diagnosed from positive cultures of blood, cerebro-spinal fluid or bone/joint aspirate in the presence of signs. Positive cultures were the "gold standard" against which the performance of CRP > or = 1.0 mg/dL, abnormal white cell counts (WCC), absolute neutrophil (ANC) and platelet counts were compared.

RESULTS

Of 152 septic screens, 30 (20%) had positive cultures. From analysis of the receiver operating characteristic (ROC) curve, CRP > or = 0.7 mg/dL rather than CRP > or = 1.0 mg/dL appeared a better cut-off for screening. The sensitivity, specificity, positive and negative predictive values of CRP > or = 0.7 mg/dL were 56%, 72%, 71% and 57% respectively. Only abnormal platelet counts had similar efficiency as CRP. Abnormal WCC had the lowest sensitivity and positive predictive value while abnormal ANC had the lowest specificity and negative predictive value among them.

CONCLUSION

CRP assay using laser nephelometry is a valuable adjunct in screening for neonatal sepsis, complementing clinical decision-making.

Williams syndrome--the Singapore General Hospital experience

Williams syndrome first described in 1961 is generally characterised by mental deficiency, gregarious personality, unusual "elfin" facies, supravalvular aortic stenosis and idiopathic infantile hypercalcaemia. Patients with Williams syndrome show a hemizygous submicroscopic deletion of 7q11.23 detectable by fluorescent in-situ hybridisation (FISH). The deleted portion of the chromosome corresponds to the Elastin gene. We report 3 girls with characteristics of Williams syndrome in whom the diagnosis was confirmed by demonstration of the hemizygous deletion of 7q11.23 in the karyotype by FISH. These patients, aged 6, 7 and 10 years, showed the characteristic facies and gregarious personalities. Some developmental delay with mild mental deficiency and dysmorphic facies were prominent features in the initial presentation. Cardiac lesions found in these patients were small patent ductus arteriosus which closed, pulmonary valvular stenosis and mitral valve prolapse associated with mitral regurgitation respectively. Hypercalcaemia was not documented in these patients. Learning difficulty was a major issue and all patients required special schooling. Chromosome analyses done on peripheral blood were found to be normal in all patients. FISH using the Elastin Williams Syndrome Chromosome Region (WSCR) probes (oncor) showed the hemizygous deletion of 7q11.23. Diagnosis of Williams syndrome can now be confidently confirmed with the help of FISH.

Mortality among infants with high-risk congenital diaphragmatic hernia in Singapore

Several factors suggested to predict mortality in congenital diaphragmatic hernia (CDH) have not always been applicable in different centers. A retrospective review was conducted of 19 consecutive neonates in Singapore in whom CDH was diagnosed within 12 hours of birth to identify factors associated with mortality. Of the 19 cases, 15 (79%) were diagnosed using antenatal ultrasonography. Eight (42%) underwent primary repair at a median age of 23 hours (range, 12 to 50 hours). Of the 19 infants, 15 died (mortality rate, 79%). Survivors until hospital discharge were compared with nonsurvivors. Antenatal diagnosis and stomach position in left-sided defects had no effect on outcome, although polyhydramnios tended to be associated with nonsurvival. Significant postnatal factors associated with mortality included a low arterial pH level, low initial arterial-alveolar oxygen ratio, high initial alveolar-arterial oxygen gradient, as well as high oxygenation and ventilation indices. These results reflect difficulty in oxygenation because of pulmonary hypoplasia despite evidence of adequate ventilation. There was no difference between survivors and nonsurvivors in either their initial or best postductal blood gases. The "Bohn quadrants" did not aid in predicting survival of infants who underwent repair because all eight such infants had best postductal carbon dioxide values of less than 40 mm Hg and ventilation indices of less than 1,000. Yet only four (50%) survived until hospital discharge. Large-scale evaluation of these factors may be required in the future to demonstrate their validity and reliability because of changing management strategies for CDH.

Staging of nasopharyngeal carcinoma: evaluation of N-staging by Ho and UICC/AJCC systems. Union Internationale Contre le Cancer. American Joint Committee for Cancer

To evaluate the prognostic accuracy of N-staging by Ho's and the UICC/AJCC systems, 5020 patients with undifferentiated or poorly differentiated squamous cell carcinoma of the nasopharynx treated at the Queen Elizabeth Hospital, Hong Kong in the period 1976-1985 were analysed retrospectively. They were initially staged with Ho's system, but detailed records of nodal involvement allowed accurate retrospective restaging with the UICC/ AJCC (1988) system. Staging assessment depended almost entirely on physical examination; only 14% of patients had additional investigations with computed tomography. To evaluate the independent significance of different nodal parameters, T-stage adjusted analyses of the 4730 patients presenting without distant metastases were performed. Both N-staging systems showed a strongly significant overall correlation with distant failures and cancer-specific deaths. A significant trend was also shown for nodal failures in node-positive patients. Ho's system was superior in predicting distant failures, while the UICC/AJCC system was superior for nodal failures. However, even with due adjustment for level, the independent significance of nodal size, laterality and fixity could be demonstrated. After adjustment for UICC/AJCC N-stage, both level and fixity were also significant. Furthermore, when adjusted for all other meaningful parameters, there were no significant differences between ipsilateral and contralateral involvement, upper and mid-level extent, and nodal size < or = 3 cm or > 3- < or = 6 cm. N-staging can be further optimized by a newly proposed system incorporating fixity (movable versus fixed), level (upper-mid versus lower), size (greatest diameter < or = 6 cm versus > 6 cm), and laterality (unilateral versus bilateral) as staging criteria.

Measuring the adoption of consistent use of condoms using the stages of change model. AIDS Community Demonstration Projects

The stages of behavior change model has been used to understand a variety of health behaviors. Since consistent condom use has been promoted as a risk-reduction behavior for prevention of human immunodeficiency virus (HIV) infection, an algorithm for staging the adoption of consistent condom use during vaginal sex was empirically developed using three considerations: HIV prevention efficacy, analogy with work on staging other health-related behaviors, and condom use data from groups at high risk for HIV infection. This algorithm suggests that the adoption of consistent condom use among persons at high risk can be meaningfully measured with the model. However, variations in the algorithm details affect both the interpretation of stages and apportionment of persons across stages.

Effect of time, dose and fractionation on local control of nasopharyngeal carcinoma

To study the effect of radiation factors on local control of nasopharyngeal carcinoma, 1008 patients with similarly staged T1N03M0 disease (Ho's classification) were retrospectively analyzed. All patients were treated by megavoltage irradiation alone using the same technique. Four different fractionation schedules had been used sequentially during 1976-1985: with total dose ranging from 45.6 to 60 Gy and fractional dose from 2.5 to 4.2 Gy. The median overall time was 39 days (range = 38-75 days). Both for the whole series and 763 patients with nodal control, total dose was the most important radiation factor. The hazard of local failure decreased by 9% per additional Gy (p < 0.01). Biological equivalents expressed in terms of Biologically Effective Dose or Nominal Standard Dose also showed strong correlation. Fractional dose had no significant impact. The effect of overall treatment time was insignificant for the whole series, but almost reached statistical significance for those with nodal control (p = 0.06). Further study is required for elucidation, as 85% of patients completed treatment within a very narrow range (38-42 days), and the possible hazard is clinically too significant to be ignored.

T1 nasopharyngeal carcinoma: the effect of waiting time on tumor control

PURPOSE

To study the effect of unperturbed tumor growth on the control of nasopharyngeal carcinoma.

METHODS AND MATERIALS

This is a retrospective analysis of 290 patients with T1N0-3M0 disease (Ho's classification) treated by the same technique and dose schedule to the nasopharyngeal region. The median interval from diagnosis to commencement of irradiation was 26 days (range: 8-68 days). Cox proportional hazards analyses were performed to study the independent effect of waiting time on the probability of failure at various sites. Actuarial failure-free survival of patients with delay < 22 days, 22-28 days and > 28 days were also compared to illustrate the clinical observation.

RESULTS

Both tests showed that waiting time had no significant impact on local failure: The N-stage stratified hazard ratio was 0.985 per day, and the 10-year local failure-free survival for the three groups was 76%, 80%, and 82%, respectively. A similar result was obtained for nodal control in patients with our scheduled neck irradiation. Although the p value of all tests failed to reach statistical significance, the N-stage stratified hazard ratio for distant failure was 1.020 per day, and the corresponding metastasis-free survival in patients with N2-3 disease was 70%, 65%, and 52%, respectively. For node-negative patients without elective neck irradiation, the hazard ratio was 1.019 per day, with the corresponding regional failure-free rates at 57%, 62%, and 33%, respectively.

CONCLUSION

Delay in initiation of treatment to the primary target (within the range observed) did not affect the control rate at irradiated sites, but there was a trend (though statistically insignificant) towards increase in failures at untreated sites that were clinically too serious to be ignored.

Retrospective analysis of patients with nasopharyngeal carcinoma treated during 1976-1985: survival after local recurrence

PURPOSE

To study the value of re-irradiation, the overall survival and pattern of failures for patients with nasopharyngeal recurrence.

METHODS AND MATERIALS

All the 891 patients with local recurrence following radiotherapy for nasopharyngeal carcinoma during 1976-1981 were retrospectively analyzed. Only 70% of them had local failure alone at the time of detection, and the T-stage distribution (by Ho's system) was 31% rT1, 16% rT2, 51% rT3, and 1% rT?. Seven hundred and six (79%) patients had been re-irradiated with various techniques and doses. Among those who failed, 50 had further irradiation.

RESULTS

The overall 5- and 10-year actuarial cancer-specific survival rates were 14% and 9%, respectively. Patients with rT3 disease had the worst prognosis. Successful local salvage was achieved in 32% of those re-irradiated (26% of the whole series). The highest control rate was achieved by those treated with external radiotherapy to 60 Gy (equivalent) or above. Only 8/50 patients responded to the third course of radiotherapy. The cumulative incidence of late post-re-irradiation sequelae was 24%, and the treatment mortality rate 1.8%. Besides local failure, 54% had regional relapse and/or distant metastasis. Thus, only 16% of recurrent patients were totally disease-free at final assessment.

CONCLUSION

The overall prognosis for patients with nasopharyngeal recurrence was grave. High dose re-irradiation could achieve successful local salvage in a substantial number of patients with early recurrence, but late complications did occur. Furthermore, high incidence of failure at other sites was observed.

Nasopharyngeal carcinoma: local control by megavoltage irradiation

This is a retrospective analysis of the long-term local control in 4128 patients with non-disseminated nasopharyngeal carcinoma treated solely by megavoltage irradiation during the years 1976-1985. The T-stage distribution according to Ho's classification was T1 37%, T2 14% and T3 49%. Different fractionation schedules had been employed at different periods, and the median dose to the primary target was equivalent to 65 Gy by time dose fractionation calculation. In 8% (344) of patients the tumour failed to regress completely after the basic course, but 89% (148/167) of those suitable for salvage with additional irradiation eventually attained complete local remission. The cumulative incidence of local failure was 24% (5% persistence, 19% recurrence). The 10-year actuarial local failure-free survival was 67%. While patients with T2 and T3a tumours achieved local control comparable to T1, those with T3c-d had the poorest control (with highest incidence of persistence and advanced recurrence). T-stage adjusted analyses suggested a significant trend of dose-response: the odds ratios for local failure were 1.16 and 1.86, respectively, when patients given 60-63 Gy and 55-59 Gy were compared with those given 64 Gy or above (p value = 0.0018). Patients treated during 1981-1985 achieved higher local failure-free survival than those treated during 1976-1980 (75% versus 70% at 5 years, p value = 0.0013). The possible attributes are studied, and ways for future optimization of treatment discussed.

Definitive radiotherapy for carcinoma of the oral tongue

This is a retrospective analysis of 117 patients with carcinoma of the oral tongue treated by definitive radiotherapy during 1979-1990. Sixty-seven per cent of patients presented with T1-2 disease. Their cumulative incidence of local failure was 10% (5/50) for those suitable for treatment with implant alone, 81% (13/16) for those treated with external irradiation alone and 67% (8/12) after combined treatment. These differences could largely be explained by selection factors as smaller and less bulky tumours generally were selected for implant treatment. Among the patients who achieved local control, there was no incidence of regional relapse (0/9) for those with elective neck irradiation, but 33% (15/46) for those without. This incidence correlated with size of primary tumour. Radiotherapy achieved effective local control in 13% (5/39) of T3-4 tumours, and regional control in 43% (12/28) of N1-3 cases. Only 32% (24/76) of patients with local and/or regional recurrence were successfully salvaged. Ways of improving the treatment are discussed.

Retrospective analysis of nasopharyngeal carcinoma treated during 1976-1985: late complications following megavoltage irradiation

A retrospective analysis was undertaken of the late complications observed in 4527 patients with nasopharyngeal carcinoma treated by megavoltage radiotherapy during the years 1976-1985. Unconventional fractionation schedules were used because of serious resource limitations. The median equivalent doses were 65 Gy to the nasopharyngeal region and 53 Gy to the cervical region. 707 patients had reirradiation for local recurrences and 250 for regional relapses. The 10-year actuarial cancer-specific survival was 47%, and the corresponding all-complication-free and neurological-complication-free rates were 40% and 72%, respectively. Altogether, 1395 (31%) patients developed one or more late irradiation sequelae. The majority were mild soft-tissue damages, but 322 (7%) had significant functional disturbances, from which 62 (1%) died. Neurological damage that occurred in 450 (10%) patients constituted the major morbidity and accounted for all but three of the treatment mortalities. The cumulative incidence of the various complications is summarized, and the data recorded in the literature reviewed in order to give a proper perspective of the problem. Patients treated during 1981-1985 had a significantly higher actuarial encephalomyelopathy-free rate than those treated during 1976-1980, but the incidence-free rates for the other neurological complications remained unimproved, suggesting that the improvement could be mainly attributed to additional shielding for the brainstem rather than the reduction of dose from 3.8-4.2 Gy to 2.5 Gy per fraction.

Retrospective analysis of 5037 patients with nasopharyngeal carcinoma treated during 1976-1985: overall survival and patterns of failure

This is a retrospective analysis of 5037 patients with squamous cell carcinoma of the nasopharynx treated during the years 1976-1985. The stage distribution according to Ho's classification was 9% Stage I, 13% II, 50% III, 22% IV, and 6% Stage V. Only 4488 (89%) patients had a full course of megavoltage radiation therapy. The median equivalent dose to the nasopharyngeal region was 65 Gy and cervical region in node-positive patients 53 Gy. Seventy percent (906/1290) of the node-negative patients had no prophylactic neck irradiation. The overall actuarial 10-year survival rate was 43%, and the corresponding failure-free survival 34%. Altogether, 4157 (83%) patients achieved complete remission lasting more than 6 months, but 53% (2205/4157) of them relapsed after a median interval of 1.4 years. The 10-year actuarial local, regional, and distant failure-free rates were 61%, 64%, and 59%, respectively. Thirty-eight percent (338/891) of all patients with local recurrence achieved second local remission. The local complete remission rate with aggressive re-irradiation alone was 47% (333/706). But 37% (124/338) of the responders recurred the second time. The incidence of distant failure correlated significantly with both the N-stage and the T-stage, with the highest (57%) occurring in patients with N3 disease. The incidence of nodal relapse in node-negative patients was 11% (44/384) among those given prophylactic neck irradiation, but 40% (362/906) among those without. Therapeutic irradiation achieved a complete regional remission rate of 90% (306/339). However, despite successful salvage, these patients had a significantly higher distant failure rate than those without nodal relapse, even if they remained local-failure-free (21% vs 6%). Patients treated during 1981-1985 achieved significantly better treatment results than those treated during 1976-1980, especially in terms of the overall survival (57% vs 47% at 5-year), the overall failure-free survival (42% vs 35% at 5-year), and the local failure-free rate (70% vs 63% at 5-year). The possible contributing factors are discussed.

Noonan syndrome with spontaneous chylothorax at birth

A female Chinese infant having the features of Noonan syndrome presented with acute respiratory distress at birth, secondary to a large spontaneous left-sided chylothorax. This condition must be recognized early in such infants, as prompt thoracentesis is life-saving.

Cardiovascular, respiratory, and blood adjustments to hypoxia in the Japanese eel,Anguilla japonica

The cardioventilatory performance of the Japanese eel,Anguilla japonica, was evaluated during acute exposure to hypoxia. The eel became an oxygen conformer as ambient PO2 fell below the critical value of 110 mmHg. Although arterial and venous PO2 also fell progressively, the arterial O2 content remained constant down to an ambient PO2 of about 60 mmHg. Arterial blood O2 saturation was maintained at 85% even at 40 mmHg. The increase in the supply of O2 to the animal during hypoxia was due to a combination of adaptive adjustments: (1) an increase in ventilation: perfusion ratio brought about mainly be bradycardia; (2) an increase in respiratory exchange surface area which was manifested as an increase in branchial blood transit time and quantified as a rise in transfer factor, water-blood overlap coefficient and utilization (%); (3) an increase in blood O2 affinity and capacitance coefficient as a result of respiratory alkalosis and Bohr-Root shift and a decrease in haemoglobin allosteric modulator (GTP, ATP) concentrations in the RBC. These factors together helped to increase the efficiency of O2 transfer across the gills.

The caudal neurosecretory system. A critical evaluation of the two-hormone hypothesis

Recent information on the caudal neurosecretory system (urophysis) is collated, with special reference to cellular biology including neural relations, activity and chemistry 8 the biological principles associated with the urophysis, pharmacological analysis of the receptors for these principles, and their possible functions in a physiological sense. The existence of at least two principles, urotensins I and II, is well established. They differ pharmacologically and chemically and may arise from different cell types. At present, osmoregulation, cardiovascular regulation and reproduction are the most likely aspects of organismal physiology wherein these principles may be involved.

The effects of acetylcholine, biogenic amines and other vasoactive agents on the cardiovascular functions of the Eel, Anguilla japonica

The blood pressure in the cardinal vein, cardiac chambers and ventral and dorsal aortae have been recorded from conscious eels in water. At low doses, acetylcholine reduced the heart rate but increased the transbranchial differential blood pressure. The effects were abolished by atropine but not by tubocurarine. At doses in excess of 0.1 mug/kg, a secondary rise in arterial blood pressure was observed which could be abolished by bretylium, phentolamine or phenoxybenzamine. Catecholamines did not affect the heart rate although a transient bradycardia due to reflex inhibition could be observed with adrenaline and noradrenaline. Catecholamines increased the cardiac contractile force through an alpha-adrenergic mechanism which was blocked by phentolamine but not by propranolol. The relative potency was noradrenaline greater than adrenaline greater than isoprenaline. A beta-adrenergic receptor located in the branchial circulation led to vasodilation and decrease in transbranchial differential pressure. Both alpha-(vasoconstriction) and beta-(vasodilation) adrenergic receptors were present in the systemic circulation. Dopamine, 5-HT, GABA and bradykinin caused bradycardia abolishable by vagotomy or atropine treatment. Angiotensin II was hypertensive but did not affect the heart rate nor the transbranchial differential pressure. Tyramine caused release of endogenous catecholamines. With repeated doses, tachyphylaxis to the drug was observed. Histamine was without any obvious cardiovascular effects in the eel.