Secondary prevention of stroke: an evidence-based clinical audit in the primary care

OBJECTIVE

To audit secondary preventive care in non-acute stroke patients in a local General Outpatient Clinic of the Hospital Authority.

DESIGN

Comparison of two samples from a case series at different time-points.

SETTING

General Outpatient Clinic, Hong Kong.

PATIENTS

Non-acute stroke patients fulfilling the inclusion criteria and regularly followed up in a local General Outpatient Clinic during the audit cycle were recruited. Evidence-based audit criteria and performance standards were established after thorough literature review. A sample from this case series was compared retrospectively at two time-points. First-phase evaluation was performed in October 2009 and deficiencies were identified. After 9 months of active intervention, second-phase evaluation was performed in July 2010. Chi squared test and student's t test were used to compare the significance of relevant changes noted.

RESULTS

First-phase data showed marked deficiencies in proper assessment of cardiovascular risk factors. Satisfactory blood pressure, glucose and lipid control was evident only in 47% of the hypertensive, 45% of the diabetic, and 37% of the dyslipidaemic stroke patients, respectively. After 9 months of implementing changes, significant improvements were noted with respect to standard targets being achieved. In the second phase, more comprehensive tackling of cardiovascular risk factors was noted, with satisfactory blood pressure control in 73% of hypertensive patients, and adequate metabolic control in 62% diabetic patients (P<0.01 for both). Only 59% of the dyslipidaemic stroke patients had optimal lipid control, though their mean low-density lipoprotein concentration was significantly reduced (P<0.05).

CONCLUSION

This study provided a valuable lesson in identifying deficiencies in secondary prevention for stroke patients managed in a local primary care facility. Using a team approach intervention, quality assurance was promoted and a definite impact on patient care was demonstrated.

Sequential expression of putative stem cell markers in gastric carcinogenesis

BACKGROUND

Gastric carcinogenesis has been well documented in the step-wise histopathological model, known as Correa pathway. Several biomarkers including CD44, Musashi-1 and CD133 have been reported as putative stem cell (PSC) markers.

METHODS

We investigated expression of PSC markers CD44, Musashi-1 and CD133 in relation to gastric carcinogenesis and prognosis and chemoresponse. Immunohistochemistry staining was performed in gastric cancer (GC) clinical specimens representing different steps of the Correa pathway. Gastric cancer samples taken before and after neoadjuvant chemotherapy with docetaxel, cisplatin and capecitabine (DCX) were also evaluated for PSC marker expression.

RESULTS

We showed that the expression of three PSC markers was significantly elevated in GC relative to normal gastric mucosa (P<0.001 for each marker). Precancerous lesions, including intestinal metaplasia and dysplasia, demonstrated increased expression of CD44 and Musashi-1. CD133 was predominantly expressed along the border between intramucosal carcinoma and connective tissue at later stages. High CD44 and CD133 expression showed prognostic value for worse patient survival (P=0.014 and P=0.019, respectively). A small number of tumours with high expression of CD44 and CD133 showed pathological response to DCX-based neoadjuvant chemotherapy.

CONCLUSION

CD44 and Musashi-1 are frequently expressed in both premalignant gastric lesions and invasive GC, whereas CD133 expression is restricted mainly to neoplastic tissues.

Relaxin causes selective outward remodeling of brain parenchymal arterioles via activation of peroxisome proliferator-activated receptor-γ

Brain parenchymal arterioles (PAs), but not pial arteries, undergo hypotrophic outward remodeling during pregnancy that involves peroxisome proliferator-activated receptor-γ (PPARγ) activation. Relaxin, a peptide hormone produced during pregnancy, is involved in systemic and renal artery remodeling and activates PPARγ in vitro. Thus, we hypothesized that relaxin is involved in the selective outward remodeling of PAs through a PPARγ-dependent mechanism. Nonpregnant rats were treated with relaxin (4 μg/h, osmotic minipump), relaxin plus PPARγ inhibitor GW9662 (10 mg/kg/d), or vehicle for 10 d. Vascular function and structure were compared in isolated and pressurized middle cerebral arteries (MCAs) and PAs taken from the same animals. Relaxin treatment increased serum relaxin to the level of pregnancy (54 ng/ml) and increased passive wall thickness (hypertrophy; 70 ± 5 vs. 54 ± 4 μm in vehicle; P<0.05) and inner diameter (outward remodeling; 10.6 ± 0.5 vs. 8.0 ± 0.6 μm in vehicle; P<0.05) in PAs, but not in MCAs. This hypertrophic outward remodeling was prevented by GW9662 that had diameters (57 ± 3 μm) and wall thickness (8.6 ± 1.0 μm) similar to vehicle. GW9662 also prevented relaxin-induced changes in PPARγ target gene expression. These results suggest that relaxin produced during pregnancy may be partly responsible for selective remodeling of PAs during pregnancy through a mechanism involving PPARγ

Cerebral vascular adaptation to pregnancy and its role in the neurological complications of eclampsia

The cerebral circulation has a central role in mediating the neurological complications of eclampsia, yet our understanding of how pregnancy and preeclampsia affect this circulation is severely limited. Here, we show that pregnancy causes outward remodeling of penetrating arterioles and increased capillary density in the brain due to activation of peroxisome proliferator-activated receptor-γ (PPARγ), a transcription factor involved in cerebrovascular remodeling and highly activated in pregnancy. Pregnancy-induced PPARγ activation also significantly affected cerebral hemodynamics, decreasing vascular resistance and increasing cerebral blood flow by ∼40% in response to acute hypertension that caused breakthrough of autoregulation. These structural and hemodynamic changes in the brain during pregnancy were associated with substantially increased blood-brain barrier permeability, an effect that could promote passage of damaging proteins into the brain and cause the neurological complications of eclampsia, including seizure.

Effect of PPARγ inhibition during pregnancy on posterior cerebral artery function and structure

Peroxisome proliferator-activated receptor-γ (PPARγ), a ligand-activated transcription factor, has protective roles in the cerebral circulation and is highly activated during pregnancy. Thus, we hypothesized that PPARγ is involved in the adaptation of cerebral vasculature to pregnancy. Non-pregnant (NP) and late-pregnant (LP) rats were treated with a specific PPARγ inhibitor GW9662 (10 ]mg/kg/day, in food) or vehicle for 10 days and vascular function and structural remodeling were determined in isolated and pressurized posterior cerebral arteries (PCA). Expression of PPARγ and angiotensin type 1 receptor (AT1R) in cerebral (pial) vessels was determined by real-time RT-PCR. PPARγ inhibition decreased blood pressure and increased blood glucose in NP rats, but not in LP rats. PPARγ inhibition reduced dilation to acetylcholine and sodium nitroprusside in PCA from NP (p < 0.05 vs. LP-GW), but not LP rats. PPARγ inhibition tended to increase basal tone and myogenic activity in PCA from NP rats, but not LP rats. Structurally, PPARγ inhibition increased wall thickness in PCA from both NP and LP rats (p < 0.05), but increased distensibility only in PCA from NP rats. Pregnancy decreased expression of PPARγ and AT1R (p < 0.05) in cerebral arteries that was not affected by GW9662 treatment. These results suggest that PPARγ inhibition had significant effects on the function and structure of PCA in the NP state, but appeared to have less influence during pregnancy. Down-regulation of PPARγ and AT1R in cerebral arteries may be responsible for the lack of effect of PPARγ in cerebral vasculature and may be part of the vascular adaptation to pregnancy.

Comparison of Chinese and Western rifapentines and improvement of bioavailability by prior taking of various meals

Bioavailability was measured by rifapentine (RPE) serum concentrations and by the urinary ratio between RPE and creatinine, in specimens obtained 4-50 h after 600 mg RPE preceded by food. The bioavailabilities of RPEs manufactured in China and by a Western manufacturer were similar after a standard English breakfast, and serum concentrations were also similar to those obtained in an earlier Italian study following a complex meal. Although absorption of RPE was unsatisfactory after lipid-rich biscuits or shortbread, absorption after egges and toast was excellent and was nearly as good after a fast-food sandwich. The urinary measure of bioavailability at 26 h appeared as efficient as peak serum estimations at 6, 8 and 26 h. Fast-food sandwiches are being taken before RPE in a current clinical trial of Chinese RPE in Hong Kong.

Multicenter phase II study of gemcitabine and oxaliplatin in advanced nasopharyngeal carcinoma--correlation with excision repair cross-complementing-1 polymorphisms

BACKGROUND

Nasopharyngeal carcinoma (NPC) is a platinum-sensitive cancer and excision repair cross-complementing group 1 (ERCC1) polymorphisms have been shown to predict survival in several cancers following platinum therapy.

PATIENTS AND METHODS

This multicenter study evaluated the activity of oxaliplatin and prolonged infusion of gemcitabine ('GEMOX' regimen) in recurrent NPC. Baseline blood samples were genotyped for the presence of ERCC1-118 gene polymorphisms.

RESULTS

Forty-two patients were recruited, of whom most (61%) had metastatic disease. Of the 40 patients evaluated for response, the respective overall response and disease control rates were 56.1% and 90.2%. At a median follow-up of 14.8 months, the respective median overall survival and time to progression were 19.6 months [95% confidence interval (CI) = 12.8-22 months] and 9 months (95% CI = 7.3-10 months). Grade 3-4 toxic effects were uncommon. The distribution of ERCC1-118 genotypes from 29 patients was C/C (n = 17, 40.5%), C/T (n = 10, 23.8%) and T/T (n = 2, 4.8%). No differences in survival or response rates were found between genotypes.

CONCLUSIONS

GEMOX is active in the treatment of recurrent NPC. Detection of single-nucleotide gene polymorphisms from genomic DNA in peripheral blood is feasible in NPC and further studies are warranted.

A randomized study of aprepitant, ondansetron and dexamethasone for chemotherapy-induced nausea and vomiting in Chinese breast cancer patients receiving moderately emetogenic chemotherapy

OBJECTIVES

This is a single center, randomized, double-blind placebo-controlled study to evaluate the NK(1)-receptor antagonist, aprepitant, in Chinese breast cancer patients. The primary objective was to compare the efficacy of aprepitant-based antiemetic regimen and standard antiemetic regimen for the prevention of chemotherapy-induced nausea and vomiting (CINV) in patients who received moderately emetogenic chemotherapy. The secondary objective was to compare the patient-reported quality of life in these two groups of patients.

PATIENTS AND METHODS

Eligible breast cancer patients were chemotherapy-naive and treated with adjuvant AC chemotherapy (i.e. doxorubicin 60 mg/m(2) and cyclophosphamide 600 mg/m(2)). Patients were randomly assigned to either an aprepitant-based regimen (day 1, aprepitant 125 mg, ondansetron 8 mg, and dexamethasone 12 mg before chemotherapy and ondansetron 8 mg 8 h later; days 2 through 3, aprepitant 80 qd) or a control arm which consisted of standard regimen (day 1, ondansetron 8 mg and dexamethasone 20 mg before chemotherapy and ondansetron 8 mg 8 h later; days 2 through 3, ondansetron 8 mg bid). Data on nausea, vomiting, and use of rescue medication were collected with a self-report diary, patients quality of life were assessed by self-administered Functional Living Index-Emesis (FLIE).

RESULTS

Of 127 patients randomized, 124 were assessable. For CINV in Cycle 1 AC, there was no significant difference in the proportion of patients with reported complete response, complete protection, total control, 'no vomiting', 'no significant nausea' and 'no nausea'. The requirement of rescue medication appears to be lesser in patients treated with the aprepitant-based regimen compared to those with the standard regimen (11% vs. 20%; P = 0.06). Assessment of FLIE revealed that while there was no difference in the nausea domain and the total score between the two groups; however, patients receiving standard antiemetic regimen had significantly worse quality of life in the vomiting domain (mean score [SD] = 23.99 [30.79]) when compared with those who received the aprepitant-based regimen (mean score [SD] = 3.40 [13.18]) (P = 0.0002). Both treatments were generally well tolerated. Patients treated with the aprepitant-based regimen had a significantly lower incidence of neutropenia (53.2% vs. 35.5%, P = 0.0468), grade >or= 3 neutropenia (21.0% vs. 45.2, P = 0.0042) and delay in subsequent cycle of chemotherapy (8.1% vs. 27.4%, P = 0.0048).

CONCLUSION

The aprepitant regimen appears to reduce the requirement of rescue medication when compared with the control regimen for prevention of CINV in patients receiving both an anthracycline and cyclophosphamide, and is associated with a better quality of life during adjuvant AC chemotherapy.

Exploring ligand recognition and ion flow in comparative models of the human GABA type A receptor

We present two comparative models of the GABA(A) receptor. Model 1 is based on the 4-A resolution structure of the nicotinic acetylcholine receptor from Torpedo marmorata and represents the unliganded receptor. Two agonists, GABA and muscimol, two benzodiazepines, flunitrazepam and alprazolam, together with the general anaesthetic halothane, have been docked to this model. The ion flow is also explored in model 1 by evaluating the interaction energy of a chloride ion as it traverses the extracellular, transmembrane and intracellular domains of the protein. Model 2 differs from model 1 only in the extracellular domain and represents the liganded receptor. Comparison between the two models not only allows us to explore commonalities and differences with comparative models of the nicotinic acetylcholine receptor, but also suggests possible protein sub-domain interactions with the GABA(A) receptor not previously addressed.

Modulation of antipyrine clearance by polysaccharide peptide (PSP) isolated from Coriolus versicolor in the rat

Polysaccharide peptide (PSP), isolated from Coriolus versicolor COV-1, has been previously shown to have immuno-stimulatory, anti-tumour and analgesic effects in animal models. When used as an adjunct in cancer chemotherapy in clinical trials carried out in China, PSP improved the quality of life in the patients by improving appetite and alleviating symptoms associated with cancer chemotherapy. In this study, the effects of non-toxic doses of PSP on phase I metabolism was investigated in the rat, using the conventional probe antipyrine. Acute PSP (3-5 micromol/kg, i.p.) treatment did not produce significant changes in antipyrine clearance. Sub-chronic treatment with PSP (1-3 micromol/kg/day, i.p., 3 days) decreased the antipyrine clearance (30-35%), with an increase in the plasma half-life (T1/2) by 55% and an increase in the area under concentration-time curve (AUC) by 61%. Total hepatic cytochrome P450 (P450) was dose-dependently decreased (32-54%) after sub-chronic, but not the acute treatment of PSP. Given that PSP can affect phase I metabolism and hepatic cytochrome P450 content, the concomitant use of PSP with other therapeutic agents that undergo phase I metabolism should be carefully monitored.

Polysaccharide peptides from COV-1 strain of Coriolus versicolor inhibit tolbutamide 4-hydroxylation in the rat in vitro and in vivo

Polysaccharide peptide (PSP), isolated from COV-1 strain of Coriolus versicolor, is commonly used as an adjunct in cancer chemotherapy in China. In this study, the effects of whole PSP extract and water extract of PSP on 4-hydroxylation of tolbutamide were investigated in rat liver microsomes in vitro and in vivo in the rat. Both the whole PSP extract and the water soluble fraction (0.5-20 microM) decreased the metabolism of tolbutamide to 4-hydroxytolbutamide in vitro. Enzyme kinetics studies showed that PSP inhibited tolbutamide 4-hydroxylase activity in a competitive, concentration-dependent manner. The whole PSP extract had a Ki value of 12.6 microM and IC50 at 18.4 microM, while the water extract had a Ki value of 6.9 microM and IC50 at 9.8 microM. Sulphaphenazole, a specific human CYP2C9 inhibitor, showed a Ki value of 30.8 microM and IC50 at 44.0 microM in the test system. In the pharmacokinetic studies in vivo, acute PSP (4 micromol/kg, i.p.) treatment did not produce significant changes in tolbutamide clearance, but produced a decrease in the Cinitial (7.4%) and an increase in the Vd (7.4%). Sub-chronic pre-treatment of PSP (1-2 micromol/kg/day, i.p.) for three days did not affect the clearance and AUC of tolbutamide, but the Cinitial was decreased, together with increases in the T1/2, and Vd. The formation of 4-hydroxytolbutamide in vivo was decreased in both acute and sub-chronic studies. Taken together, this study demonstrated the PSP can inhibit tolbutamide 4-hydroxylation both in vitro and in vivo. Despite the fact that CYP isoforms that metabolise tolbutamide are different between rat and human liver due to different catalytic characteristics, and rat studies may not be directly extrapolatable to man, the concomitant use of PSP with other CYP2C substrates should be carefully monitored.

Regulation of p53 and suppression of apoptosis by the soluble guanylyl cyclase/cGMP pathway in human ovarian cancer cells

Dysregulated apoptosis plays a critical role in the development of a number of aberrant cellular processes, including tumorigenesis and chemoresistance. However, the mechanisms that govern the normal apoptotic program are not completely understood. Soluble guanylyl cyclase (sGC) and cyclic guanosine monophosphate (cGMP) promote mammalian cell viability via an unknown mechanism and p53 status is a key determinant of cell fate in human ovarian cancer cells. Whether an interaction exists between these two determinants of cell fate is unknown. We hypothesized that basal sGC activity reduces p53 content and attenuates p53-dependent apoptosis in human ovarian cancer cells. Suppression of sGC activity with the specific inhibitor 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ) lowered cGMP content, and increased p53 protein content and induced apoptosis in three ovarian cancer cell lines, effects which were attenuated by the cGMP analog 8-Br-cGMP and by Atrial Natriuretic Factor, an activator of particulate guanylyl cyclase, which circumvent the inhibition of sGC. ODQ prolonged p53 half-life, induced phosphorylation of p53 on Ser15, and upregulated the p53-dependent gene products p21, murine double minute-2, and the proapoptotic, p53-responsive gene product Bax. ODQ activated caspase-3, and ODQ-induced apoptosis was inhibited by overexpression of X-linked inhibitor of apoptosis Protein. Pretreatment with the specific p53 inhibitor pifithrin or downregulation of p53 using a specific small inhibitory RNA significantly attenuated ODQ-induced apoptosis. Moreover, ODQ-induced upregulation of p21 and Bax and ODQ-induced apoptosis were significantly reduced in a p53 mutant cell line relative to the wild-type parental cell line. Thus, the current study establishes that basal sGC/cGMP activity regulates p53 protein stability, content, and function, possibly by altering p53 phosphorylation and stabilization, and promotes cell survival in part through regulation of caspase-3 and p53.

Effects of polysaccharide peptide (PSP) from Coriolus versicolor on the pharmacokinetics of cyclophosphamide in the rat and cytotoxicity in HepG2 cells

Polysaccharide peptide (PSP), isolated from Coriolus versicolor COV-1, has been shown to restore the immunological effects against cyclophosphamide-induced immuno-suppression, although the mechanism(s) involved remain uncertain. This study investigated the PSP-cyclophosphamide interaction by studying the effects of PSP on the pharmacokinetic of cyclophosphamide in the rat and the effect of PSP on the cytotoxic effects of cyclophosphamide on a cancer cell line (HepG2 cells). In the pharmacokinetic studies in the rat, acute pre-treatment of PSP (4 micromol/kg/day, i.p.) decreased the clearance (CL) of cyclophosphamide by 31%, with a concomitant increase in the area under concentration-time curve (AUC) by 44%, and prolongation of the plasma half-life (T(1/2)) by 43%. Sub-chronic pre-treatment of PSP (2 micromol/kg/day, i.p., 3 days) decreased the CL of cyclophosphamide by 33%, with a concomitant increase in the AUC by 50%, and prolongation of the plasma T(1/2) by 34%. In cytotoxicity studies using HepG2 cells, non-toxic dose of PSP (1-10 microM) enhanced the cytotoxicity of cyclophosphamide. PSP at 10 microM further decreased HepG2 cell viability by 22% compared to when cyclophosphamide was present alone. In summary, PSP enhanced the cytotoxic effect of cyclophosphamide on a cancer cell line in vitro and altered the pharmacokinetics of cyclophosphamide in vivo in the rat. Both of these effects may be beneficial in the use of PSP as an adjunct to cyclophosphamide treatment.

Polysaccharide peptides from COV-1 strain of Coriolus versicolor induce hyperalgesia via inflammatory mediator release in the mouse

Polysaccharide peptide (PSP), isolated from Coriolus versicolor COV-1, has been widely used as an adjunct to cancer chemotherapy and as an immuno-stimulator in China. In this study, the anti-nociceptive effects of PSP were investigated in two different pain models in the mouse. In the acetic acid-induced writhing model, initial studies showed that PSP decreased the number of acetic acid-induced writhing by 92.9%, which, by definition, would constitute an analgesic effect. However, further studies showed that PSP itself induced a dose-dependent writhing response. Studies on inflammatory mediator release showed that PSP increased the release of prostaglandin E2, tumor necrosis factor-alpha, interleukin-1beta, and histamine in mouse peritoneal macrophages and mast cells both in vitro and in vivo. The role of inflammatory mediator release in PSP-induced writhing was confirmed when diclofenac and dexamethasone decreased the number of writhing responses by 54% and 58.5%, respectively. Diphenhydramine totally inhibited the PSP-induced writhing. In the hot-plate test, PSP dose-dependently shortened the hind paw withdrawal latency, indicative of a hyperalgesic effect. The hyperalgesic effect was reduced by pretreatment with the anti-inflammatory drugs. In conclusion, the PSP-induced hyperalgesia was related to activation of peritoneal resident cells and an increase in the release of inflammatory mediators.

Unbinding pathways of an agonist and an antagonist from the 5-HT3 receptor

The binding sites of 5-HT3 and other Cys-loop receptors have been extensively studied, but there are no data on the entry and exit routes of ligands for these sites. Here we have used molecular dynamics simulations to predict the pathway for agonists and antagonists exiting from the 5-HT3 receptor binding site. The data suggest that the unbinding pathway follows a tunnel at the interface of two subunits, which is approximately 8 A long and terminates approximately 20 A above the membrane. The exit routes for an agonist (5-HT) and an antagonist (granisetron) were similar, with trajectories toward the membrane and outward from the ligand binding site. 5-HT appears to form many hydrogen bonds with residues in the unbinding pathway, and experiments show that mutating these residues significantly affects function. The location of the pathway is also supported by docking studies of granisetron, which show a potential binding site for granisetron on the unbinding route. We propose that leaving the binding pocket along this tunnel places the ligands close to the membrane and prevents their immediate reentry into the binding pocket. We anticipate similar exit pathways for other members of the Cys-loop receptor family.

Animal model for the pathogenesis of reactive amyloidosis

The pathogenesis of amyloidosis is not well understood. Here, Zafer Ali-Khan, Weihua Li and Sic L. Chan present a metazoan parasite mouse model of reactive amyloidosis, review the relationship between chronic inflammation and multiorgan AA amyloidosis and postulate how ubiquitin might function in the processing of serum amyloid A and in AA amyloid formation in the endosomes-lysosomes of activated murine reticuloendothetial cells.

Appropriateness of the use of parenteral nutrition in a local tertiary-care hospital

INTRODUCTION

Parenteral nutrition (PN) is an important supportive therapy for critically ill patients who have non-functioning gut. However, it is an expensive therapy and carries significant complications. The objective of our audit was to determine the appropriateness of prescription of PN in our hospital, based on the American Society for Parenteral and Enteral Nutrition (ASPEN) 2002 guidelines. In our hospital, the prescription of PN is managed by the Nutrition Support Team.

MATERIALS AND METHODS

A retrospective review of adult patients prescribed with PN in 2001 was undertaken. Data on patient demographics, underlying diagnoses, indications, duration and routes administration were collected. The use of PN was classified as "appropriate", "inappropriate" or "indeterminate" by the authors based on the above guidelines.

RESULTS

145 patients were prescribed PN in 2002. We were able to review the case notes for 137 patients. One patient received PN on 2 separate admissions. Of the 138 courses of PN (in 137 patients) reviewed, there were 88 males with the median age of 61 years (range, 16 to 91 years). 81.2% were surgical patients and of the remaining patients, 10.1% had haematological malignancies. The 2 most common indications were postoperative ileus (37.0%) and post-surgical complications (14.5%). The median duration of PN prescription was 9 days (range, 1 to 175 days). 109 (78.3%) courses of PN were classified as "appropriate", 22 (15.9%) courses as "inappropriate" and 7 (5.8%) courses as "indeterminate". Patients from the postoperative ileus group contributed to 10 (45.5%) patients with "inappropriate" indications; the main reason was premature initiation of PN. Of the patients considered to show "inappropriate" indications, 15 courses (68.1%) were prescribed for less than 7 days. PN was discontinued in 78% of courses due to satisfactory resumption of oral or enteral intake. The mean duration of PN use for patients with "inappropriate" indication was significantly shorter than for patients with "appropriate" indication (7.7 +/- 5.3 days versus 15.8 +/- 20.0 days, P = 0.002). 99.3% of PN courses were given via the central routes (with central vein cannulation or PICC). These lines were specifically inserted for PN in 60.14% of the cases.

CONCLUSION

Our audit showed that 15.9% of PN prescriptions were inappropriate according to the ASPEN guidelines. This was largely attributed to premature initiation of PN for postoperative ileus. We believe that these PN courses could have been avoided if these patients had been tried on naso-jejunal tube feeding, or oral nutrition with the use of prokinetics during the postoperative period.

Evidence for Nonadrenoceptor Responses to Imidazoline Derivatives in the Porcine Isolated Rectal Artery

High concentrations of phentolamine, efaroxan, and idazoxan were found to produce nonadrenoceptor contractions of the porcine isolated rectal artery previously exposed to U46619 and forskolin. These responses were insensitive to the putative imidazoline I(3) receptor antagonist KU-14R, unlike those previously reported in this preparation for oxymetazoline. The pharmacologic nature of this response and the obligate requirement for preconstriction suggests that these imidazoline derivatives modulate ion channel function through a novel nonadrenergic site.

Prevalence and predictors of default from tuberculosis treatment in Hong Kong

OBJECTIVE

To determine the prevalence and risk factors of default from tuberculosis treatment in Hong Kong.

DESIGN

Retrospective study.

SETTING

Data were obtained from programme forms completed by physicians in the Hong Kong Government Tuberculosis and Chest Service and from medical records from Hong Kong chest clinics.

PATIENTS

In all, 5917 patients registered for antituberculous drug therapy in 1996; medical records of 5757 patients were reviewed.

MAIN OUTCOME MEASURES

Patients who defaulted treatment were defined as those who had failed to collect medication for more than 2 consecutive months after the date of the last attendance during the course of treatment. Demographic and clinical characteristics, including history, treatment, and outcome, were compared between defaulters and non-defaulters, both among the whole group and among those with pulmonary disease.

RESULTS

There were 442 (8%) patients who defaulted from treatment. Forty-five percent of those who defaulted did so in the first 2 months of treatment. Key risk factors associated with non-compliance were a history of default, male sex, and a history of concomitant liver disease or lung cancer. Among patients with pulmonary tuberculosis (381 defaulters and 1537 non-defaulters), multiple drug resistance was also associated with default from treatment. Among defaulters with pulmonary disease, 39% were still bacteriologically positive at the time of default.

CONCLUSION

Default from treatment may be partially responsible for the persistent high rates of tuberculosis in Hong Kong in the past decade. Health professionals should ensure that all barriers to treatment be removed and that incentives be used to encourage treatment compliance.

Tuberculosis in Hong Kong-patient characteristics and treatment outcome

OBJECTIVES

To identify the general characteristics of patients with tuberculosis, and to evaluate their treatment outcomes.

DESIGN

Retrospective study.

SETTING

Tuberculosis and Chest Service, Department of Health, Hong Kong.

SUBJECTS AND METHODS

All patients with tuberculosis registered for treatment from 1 January 1996 to 31 December 1996 were included in the study. Information was extracted from their medical records at treatment commencement and at 12 and 24 months after treatment was instigated. Data gathered included demographic data, past treatment, site of disease, case category, treatment regimen, bacteriological status, and treatment outcome.

RESULTS

There were 5757 patients for analysis. Approximately one third of patients were aged 60 years or older, and 69.1% were male. Pulmonary disease alone occurred in 77.7% of patients, while both pulmonary and extrapulmonary diseases occurred in 8.6%. New patients comprised 84.6% of cases, and 16.3% had concomitant illnesses. There was excess risk of disease among patients who were male, elderly, or who had silicosis. Only 0.1% of patients were co-infected with human immunodeficiency virus infection. Among the 5757 cases evaluated, 1324 (23.0%) were new patients with a positive sputum smear, 299 (5.2%) were patients who were retreated with a positive sputum smear, and 4134 (71.8%) were new or retreatment patients with a negative sputum smear. The overall treatment completion rates at 12 and 24 months were 80.4% and 84.8%, respectively. Males and patients aged 60 years or older had lower treatment completion rates. Non-adherence, transfer to other services, and mortality among the elderly were key factors influencing treatment outcomes. Co-morbidity was associated with better case-holding, and this more than compensated for its effect on prolongation of treatment and mortality.

CONCLUSIONS

There was an excess risk of tuberculosis among male and elderly patients, who also had a less favourable outcome. Active screening of clearly identified risk groups may be appropriate but requires the completion of more in-depth studies and careful cost-effectiveness analyses. Further efforts with respect to case-holding are indicated to address treatment defaulting and transfer rates.

Extra-pulmonary and pulmonary tuberculosis in Hong Kong

OBJECTIVE

To compare the characteristics of patients with pulmonary and extra-pulmonary tuberculosis and to describe the organ involvement, diagnosis and treatment of extra-pulmonary tuberculosis.

MATERIALS AND METHODS

All patients with a diagnosis of tuberculosis treated by the Hong Kong Government Tuberculosis and Chest Service (Chest Service) in 1996 were studied.

RESULTS

Of the 5757 patients treated, 13.7% had extra-pulmonary tuberculosis alone and 8.6% had both extra-pulmonary tuberculosis and pulmonary tuberculosis. Extra-pulmonary tuberculosis was more common in women under 30 and over 75 years of age. Only six patients had human immunodeficiency virus (HIV) infection, of whom two had extra-pulmonary tuberculosis. The most common site of extra-pulmonary involvement was the pleura, followed by the lymph nodes. Miliary tuberculosis occurred in only 2.9%. Lymph node involvement occurred significantly higher in women, while pleural disease was significantly higher in men. The duration of treatment varied according to the site of disease, being shorter (6 months) for those with pleural disease only and >9 months for those with miliary, meningeal, gastrointestinal and genitourinary disease; 80.3% completed treatment at 12 months and 85.5% at 24 months. Of those who completed treatment, 1.4% had a relapse of disease at 24 months follow-up; there was no significant difference between those with pulmonary or extra-pulmonary disease.

CONCLUSION

In Hong Kong, extra-pulmonary tuberculosis is common, affecting 22.3% of TB patients, and is unrelated to HIV infection. There are sex differences in the organs most commonly affected. The rate of relapse of disease is low for those who completed treatment, irrespective of the site of involvement.

Tuberculosis in the elderly in Hong Kong

BACKGROUND

The rate of tuberculosis in Hong Kong has declined dramatically since the 1950s, but has remained high during the past decade, at around 110/100,000. The reason for the persistent high rate is not clear.

OBJECTIVES

To study the trend of tuberculosis in Hong Kong during the past decade (1989 to 1998) and the clinical characteristics of tuberculosis patients > or = 60 years of age, and compare them with those of the younger age groups.

METHODS

Notification rates of tuberculosis from 1989 to 1998 were obtained from the Hong Kong Government Tuberculosis and Chest Service (Chest Service), Department of Health, Hong Kong. In addition, all patients registered at the Chest Service for treatment of tuberculosis in 1996 were studied.

RESULTS

During the past decade, the notification rate of tuberculosis, which included both bacteriologically confirmed and clinically active but bacteriologically not confirmed cases, decreased in those under 60, remained unchanged in those between 60-69, and increased in those > or = 70 years of age. An increase in the rate of bacteriologically confirmed cases (sputum smear or culture positive for Mycobacterium tuberculosis) in the older age groups was observed during the same period. In 1989, 31.9% of tuberculosis cases were over the age of 60 years; this proportion increased to 45.4% in 1998. The increase in the number of cases in those > or = 60 years could almost account for the total increase in number of cases during the last decade. Patients in the older age groups had more advanced disease at the time of diagnosis, and a higher proportion had comorbid illnesses. They also had significantly higher mortality compared with the younger age groups.

CONCLUSION

The increasing longevity of the population and the high rate of tuberculosis in the elderly are important factors contributing to the persistent high rate of tuberculosis in Hong Kong in the past decade.