Religious affiliation, religious involvement, and alcohol use in Korea

This article is the first study of religious commitment and involvement of homeland Koreans as related to alcohol use. Religious affiliation and involvement are predictive of abstemiousness, but chiefly for women, who are at low risk for alcohol abuse and dependency, and not for men, who are at high risk. The frequent abstemiousness of Buddhist women results chiefly from data having to do with mothers and probably is a consequence of the women's traditional lifestyles, being both Buddhist and abstemious. Among the probably more Westernized Christians, religious involvement is most clearly associated with abstemiousness among daughters, a group at a relatively low but increasing risk for alcohol use.

Skip colonic ulceration in typhoid ileo-colitis

Colonic skip lesions are typically described in Crohn's colitis, but this phenomenon has been recognized in ulcerative colitis (skipped appendiceal involvement), Behcet's colitis, cytomegaloviral colitis, and even in Aeromonas hydrophilia and Histoplasma capsulatum infection. However, skip lesions in typhoid ileo-colitis have not been reported in the English-language literature. We report herein a patient with skip ulcers due to typhoid fever.

Apoptosis in gestational trophoblastic disease is correlated with clinical outcome and Bcl-2 expression but not Bax expression

Apoptosis has been found to play a crucial role in the pathogenesis and prognosis of many human diseases. The pathogenesis of gestational trophoblastic disease (GTD), which encompasses hydatidiform moles (HMs) and choriocarcinomas (CCAs), is not fully understood. Prognostic indicators of HM have also been scanty. In this study, we investigated apoptotic activity and the expression of two apoptosis regulatory genes, Bcl-2 and Bax, in an attempt to determine the role of apoptosis in GTD. Formalin-fixed paraffin-embedded tissue of 33 normal placentas, 14 spontaneous abortions, 14 partial moles, 34 complete moles, and eight CCAs were examined. Apoptotic activity was assessed by the terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labeling (TUNEL) method. Quantitative assessment of apoptotic index (AI) was calculated as a percentage of TUNEL-positive nuclei. Expression of Bcl-2 and Bax were assessed immunohistochemically. Extensive apoptosis was located in syncytiotrophoblasts, cytotrophoblasts, and villous stromal cells in all HM cases. Apoptosis was detected at a much lower level in spontaneous abortions and normal placentas. Moreover, in normal placentas, TUNEL positive nuclei were exclusively found in syncytiotrophoblasts. AIs were significantly different among various categories of trophoblastic lesions (P < .001) in an ascending order: normal placentas less than spontaneous abortions less than CCAs less than HMs. Furthermore, AIs of those cases that spontaneously regressed was statistically higher than those that developed persistent trophoblastic disease requiring chemotherapy. AIs of trophoblastic lesions in general inversely correlated with Bcl-2 expression (P < .001), but no significant correlation was found between AI and Bax expression (P > .5). We conclude that AI may be a useful prognostic marker for clinical progress of HMs. Bcl-2 expression is probably regulating apoptosis in normal placentas and GTD, whereas Bax expression is not. The difference in AI and Bcl-2 expression between non-molar placentas and HMs offers a potential adjunctive diagnostic tool to distinguish the two entities.

Esophageal variceal ligation by reloading with inexpensive hemorrhoidal O-ring--is an overtube necessary?

The overtube is the major cause for severe complications during endoscopic variceal ligation with a single-shot ligator. This retrospective study was designed to examine the necessity of the placement of an overtube during elective endoscopic variceal ligation. Thirty-one sessions in 18 patients were analyzed. An overtube was inserted using an over-the-scope technique in 11 sessions (group 1) but was omitted in 20 sessions (group II). The complications, technical difficulties, and operating time were analyzed. Child's grading, the size of the esophageal varices, and the number of rubber bands deployed were comparable in both groups. There was a significantly longer operating time (p < 0.01) and more oropharyngeal injury (p = 0.03) in group I than in group II. Mid esophageal injury, which was associated with resistance in withdrawing the gastroscope from the overtube, occurred in 55% of sessions in group I but in 0% of session in group II. In conclusion, the use of an overtube is associated with more complications, and it can be omitted during elective endoscopic variceal ligation.

Prediction of oesophagogastric varices in patients with liver cirrhosis

BACKGROUND

All patients with liver cirrhosis are recommended for evaluation of oesophagogastric varices (EGV) regularly. This prospective study was designed to develop a predictive model for EGV in cirrhotic patients.

METHODS

Ninety-two patients were recruited. From all patients studied, the size of palpable spleen, liver chemistry value, platelet count, prothrombin time, diameter of main portal vein and splenic length as assessed by ultrasonography were determined. Upper endoscopy was performed. Oesophageal varices (EV) and gastric varices (GV) were graded (EV, grade 1-4; GV, grade 1-3). In the predictive model, the EGV was classified into two grades (low, grade 1-2 EV or grade 1 GV; high, grade 3-4 EV or grade 2-3 GV).

RESULTS

There were 53 patients with EGV and 39 patients without EGV as determined by endoscopy. Patients with EGV had a significantly higher degree of ascites and hepatic encephalopathy, lower platelet count and longer splenic length than those without EGV. Low platelet count and presence of ascites were the significant independent predictors for high-grade EGV (concordance rate 0.83). The optimal critical value for the platelet count was 150 x 10(9)/L. Of patients without thrombocytopenia and ascites, 37% had low-grade EGV but none had high-grade EGV, whereas 38 and 35% of patients with thrombocytopenia or ascites had low and high-grade EGV, respectively. Therefore, this predictive model for high-grade varices had a positive and negative predictive value of 35 and 100%, respectively.

CONCLUSION

Endoscopic screening for EGV was not necessary until thrombocytopenia or ascites occurred.

Contribution of kasA analysis to detection of isoniazid-resistant Mycobacterium tuberculosis in Singapore

Genotypic analysis of resistance to isoniazid (INH) in Mycobacterium tuberculosis is complex due to the various genes potentially involved. Mutations in ketoacyl acyl carrier protein synthase (encoded by kasA) were present in 16 of 160 (10%) INH-resistant isolates (R121K [n = 1], G269S [n = 3], G312S [n = 11], G387D [n = 1]). However, G312S was also present in 6 of 32 (19%) susceptible strains. kasA analysis contributed marginally to the performance of INH genotypic testing in Singapore. The significance of kasA polymorphisms in INH resistance should be carefully established.

Disseminated Penicillium marneffei infection: a report of five cases in Singapore

Penicillium marneffei has emerged as an important opportunistic pathogen in HIV-infected patients in Southeast Asia. We report the first 5 cases of P. marneffei diagnosed in Singapore. All the patients were HIV-infected and were either Thai nationals or had frequently travelled to Thailand. Fever, weight loss, anaemia and papular skin lesions were common clinical manifestations in our patients, all of whom had the organism isolated from blood. Skin biopsy specimens showed histological evidence of P. marneffei in 2 patients. In 1 patient each, the organism grew in cultures of specimens from bone marrow and respiratory secretions. Amphotericin B therapy followed by itraconazole were used in 3 of our 5 patients and was associated with good clinical response and outcome.

Netilmicin pharmacokinetics in Hong Kong Chinese cancer patients

OBJECTIVES

To study the pharmacokinetics of netilmicin in Chinese haematology-oncology patients and to determine the pharmacokinetic differences, if any, between this patient subpopulation of Chinese and Caucasians.

METHODS

A prospective study was carried out in the adult oncology unit of a major hospital in Hong Kong. During a 6 week period in 1997, all patients commencing on netilmicin therapy were monitored; the patients' demographics, clinical status, netilmicin dose and regimen, and drug administration/blood sampling time were collected. Pharmacokinetic parameters were generated using the USC*PACK package based on specifics of the patients themselves and Caucasians matched for the same patients' parameters using the Bayesian alogrithms.

RESULTS

A total of 22 patients were enrolled into the study. Twenty-nine sets of levels were drawn, but only 25 sets from 18 patients (86%) were interpretable. The predicted peak (7.47+/-1.46 microg ml-1 ) and trough levels (1.39+/-0.96 microg ml-1 ) generated by USC*PACK were found to be significantly higher than the levels observed (6.01+/-1.14 microg ml-1 and 0.93+/-0.71 microg ml-1, respectively). Netilmicin clearance, volume of distribution and rate of elimination were all significantly higher in this Chinese subpopulation than those predicted for matched Caucasians. Conclusion Alterations in the netilmicin pharmacokinetics observed in our study population might be related to the disease state and/or ethics of the study patient population. Direct application of Caucasian based population pharmacokinetic parameters to this subgroup of Chinese patients may not be appropriate and may result in underdose.

Expression of glial cell line-derived neurotrophic factor and its mRNA in the nigrostriatal pathway following MPTP treatment

Striatal glial cell line-derived neurotrophic factor (GDNF) mRNA levels in both young (2-month old) and old (11-month old) C57BL/6J mice were quantified at 3, 7 and 21 days following 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) treatment. MPTP did not alter the expression of GDNF mRNA in these animals. Immunoreactive staining of GDNF in the substantia nigra and the striatum was also unchanged. In conclusion, MPTP-induced dopaminergic neurotoxicity does not elicit any changes in the expression of endogenous GDNF or its mRNA in the adult mouse brain.

Cytomegalovirus colitis in individuals without apparent cause of immunodeficiency

Cytomegalovirus infection is usually reported in immunocompromised patients. In this study, apparently immunocompetent patients with cytomegaloviral colitis were reviewed. Records with a diagnosis of cytomegaloviral colitis from January 1989 to June 1996 were retrieved for analysis. Ten patients were included (median age 70 yr). The major presenting symptoms were diarrhea and hematochezia. Ulceration was the main macroscopic finding. Rectal bleeding was mostly self-limiting. Three patients developed local complications (rectovaginal fistula in two; rectal stricture in one). In the two patients with rectovaginal fistula, lymphocytes subsets and proliferative response were entirely normal. In the other patient, low B lymphocyte count and low response to mitogen were demonstrated. However, the immunoglobulins were not suppressed and rectal biopsies revealed noncaseating granulomas, suggesting activated cell-mediated immunity. In conclusion, a high index of suspicion is crucial for early diagnosis of cytomegaloviral colitis in patients with bloody diarrhea, even though obvious evidence of immunodeficiency is lacking.

Rapid mycobacterial tuberculosis detection in bronchoalveolar lavage samples by polymerase chain reaction in patients with upper lobe infiltrates and bronchiectasis

In areas where tuberculosis is endemic, a positive sputum acid-fast bacilli (AFB) smear is frequently regarded as almost diagnostic of pulmonary tuberculosis (PTB). The main problem arises when the AFB smear is negative. The main aim of this study was to determine the clinical utility of rapid mycobacterial tuberculosis (MTB) detection in bronchoalveolar lavage (BAL) samples by polymerase chain reaction (PCR) in 52 patients who underwent diagnostic bronchoscopy for suspected PTB. These patients had either upper lobe infiltrates (n = 31) or bronchiectasis (n = 21). Mycobacterial culture is usually used as the gold standard of diagnosis. We chose to define active PTB based on positive mycobacterial cultures and/or histological evidence of caseous necrosis and AFB, and/or when there was clinical plus radiological improvement following therapy. We compared AFB smear, respiratory mycobacterial culture, BAL PCR for MTB and clinical active PTB. Four patients who were smear and culture negative had clinical and radiological clearance following anti-tuberculous therapy showing that using mycobacterial culture as a gold standard may have its limitations. When Kappa (a chance-corrected measure of agreement) was calculated for acid-fast bacilli smear and BAL PCR against our definition of active PTB, it was 0.28 (fair agreement) and 0.73 (substantial agreement), respectively. BAL PCR gave a sensitivity, specificity, positive and negative predictive values of 66.7%, 100%, 100% and 88%, respectively, for the group with upper lobe infiltrates. We also demonstrated that BAL for PCR has a good concordance with the final diagnosis of active tuberculosis.

Glucose stimulates phagocytosis of unopsonized Pseudomonas aeruginosa by cultivated human alveolar macrophages

Glucose has previously been shown to increase the in vitro phagocytosis of unopsonized Pseudomonas aeruginosa by freshly explanted murine peritoneal macrophages (PM) and cultivated alveolar macrophages (AM). This study examined the effect of glucose on the same phagocytosis process in human AM in order to determine whether this phenomenon is conserved among species. Freshly explanted human AM phagocytosed unopsonized P. aeruginosa at a low level (2 bacteria/macrophage/30 min), whereas mouse AM ingested a negligible number of P. aeruginosa (0.01 bacterium/macrophage/30 min). Glucose had no effect on this or other phagocytic processes in freshly explanted mouse or human AM. However, following in vitro cultivation for 72 h, human AM phagocytosed three to four times more unopsonized P. aeruginosa than did freshly explanted cells, but only in the presence of glucose. This glucose-inducible phagocytic response had also been observed in cultivated murine AM. Although similar increases were also detected for the phagocytosis of latex particles and complement-coated sheep erythrocytes by cultivated human AM, these processes were not glucose dependent. The lack of response to glucose in freshly explanted mouse AM was attributed to insufficient glucose transport; however, freshly explanted human AM exhibited significant facilitative glucose transport activity that was inhibitable by cytochalasin B and phloretin. Taken together, these results suggest that the process of glucose-inducible phagocytosis of unopsonized P. aeruginosa is conserved among macrophages from different species, including humans, and that AM, but not PM, required cultivation for this glucose effect to occur. Glucose transport by AM appears to be necessary but not sufficient for phagocytosis of unopsonized P. aeruginosa.

Abdominal surgery in human immunodeficiency virus (HIV) infected patients--early local experience

The prevalence of human immunodeficiency virus (HIV) infection is increasing in Singapore. The surgical experience, however, remains limited. A retrospective review of 13 HIV-positive patients requiring abdominal surgery within Singapore was done. There were 4 females and 9 males with age ranging from 21 to 44 years. Operations included appendicectomy, colectomy, splenectomy, intestinal bypass, gastrostomy and exploratory laparotomy. Pathologic findings directly related to HIV infection were found in two-fifths (5 out of 13) of these patients. A low CD4+ count or signs of full-blown acquired immunodeficiency syndrome (AIDS) were not associated with a higher likelihood of HIV-related pathology; neither did it preclude a successful outcome. There were 2 early postoperative deaths, both with HIV-related pathology. Five of our patients who survived their abdominal surgery died on follow-up with a median survival of 17 months. In patients with typical surgical problems, e.g. appendicitis and torsion of the ovary, early surgery allows for rapid recovery similar to normal surgical patients. Care of these patients is best provided by surgeons with experience and interest in this condition together with infectious diseases physicians. Even palliative surgery offers a respite from acute and often severe problems and improves the quality of life significantly. Two patients with AIDS presented with sepsis and diffuse abdominal tenderness. Subsequent laparotomy revealed only primary bacterial peritonitis. For patients with AIDS and non-localizing abdominal signs, alternative non-invasive diagnostic modalities such as computed tomographic (CT) scan should be considered.

Effect of simethicone on the accuracy of the rapid urease test

OBJECTIVE

Simethicone, which is a principal ingredient in the defoaming agent used during gastroscopy, can inhibit the growth of Helicobacter pylori (MIC, 64-128 mg/l). This prospective study was designed to evaluate the in vivo and in vitro effects of simethicone on the accuracy of the rapid urease test (RUT).

METHODS

In the in vivo study, three sets of gastric biopsies (two from the antrum, and one from the corpus) were taken from 75 patients. The first set was examined histologically, and the second set was used for the RUT (pre-simethicone RUT). Then, 25 ml simethicone (1200 mg/l) was introduced into the stomach for a contact time of 1 min. A third set of gastric biopsies was taken for the RUT (post-simethicone RUT). In the in vitro clinical study, 41 patients were recruited. The first set of gastric biopsies was used for the RUT (pre-incubation RUT). The second set was incubated in 1 ml of simethicone for 5 min before being used for the RUT (post-incubation RUT). In the spectrophotometric study, urease activity before and after incubation in simethicone for 5 min was quantified in 12 patients by measuring the absorbance at 560 nm.

RESULTS

Reading at 15 min, the concordance rate between the pre-simethicone and post-simethicone RUT was 98%. In the in vitro clinical study, the concordance rate between the pre-incubation and post-incubation RUT was 97%. The spectophotometric study showed a significant reduction of 43% in urease activity after incubation in simethicone.

CONCLUSION

The application of a defoaming agent containing simethicone does not affect the accuracy of the RUT. However, simethicone modestly suppresses urea hydrolysis.

Pseudobacteremia with amoxycillin-clavulanic acid-resistant Escherichia coli traced to cross-contamination during blood culture processing

Escherichia coli has seldom been reported to cause pseudobacteremia. The investigation of an outbreak of amoxycillin-clavulanic acid-resistant E. coli pseudobacteremia is described. Seventeen cases occurred over a five-day period. The source of the E. coli was traced to the blood culture specimen of a patient (index patient) with genuine bacteremia as a result of urinary tract infection. The other 16 case-patients had pseudobacteremia which was found to be the result of cross-contamination during subculture of blood specimens. The E. coli strain was carried over from the culture bottle of the index patient, through the contaminated gloved hands of a technician to the culture bottles of the other 16 cases. Although the pseudobacteremia occurred over a five-day period, they all resulted from cross-contamination during blood culture processing within one day. An early outbreak investigation was prompted by the unusual finding of amoxycillin-clavulanic acid resistance in the case E. coli isolates in a short period. The relatedness of the E. coli strains from the 17 cases was confirmed by arbitrary-primed polymerase chain reaction. Clinicians should be alerted to the possibility of a blood E. coli isolate being a contaminant despite its predominant role as a true pathogen.

Ventricular tachycardia after oxytocin injection in patients with prolonged Q-T interval syndrome--report of two cases

Oxytocin is widely used in obstetric settings to stimulate uterine contraction and prevent postpartum hemorrhage. Its adverse effects which include transient hypotension and increase heart rate could be life-threatening in patients with fixed cardiac output or hypotension resulting from hemorrhage. We reported two cases suspected to have preexisting prolonged Q-T interval syndrome (PQTS) who developed ventricular tachycardia immediately after intravenous injection of oxytocin. Anesthetic management of and use of oxytocic agents in patients with PQTS were discussed.

Time course of NOS expression and neuronal death in Clarke's nucleus following traumatic injury in adult rat spinal cord

The objective of this study was to investigate the influence of the length of the remaining axons on neuronal survival following axonal injury in the adult rat spinal cord. The relationship between the expression of nitric oxide synthase (NOS) and neuronal death was also studied. The time course of NOS expression and neuronal loss was observed in Clarke's nucleus at segment L1 following hemisection of the cord at either segment C3, T1, or T11. NOS-positive neurons were first observed 3 days after injury, rising significantly after 5 days, and reaching a maximum by 10-20 days post-injury. During the same period the number of neurons surviving in the nucleus decreased. The decrease began at 3 days, rapidly decreased after 5 days, and reached a minimum by 40 days post-injury. Among the three lesioned groups, the highest percentage of NOS expression and neuronal loss was observed in the group with lesions at T11, while the lowest percentage was in the group with lesions at C3. Although the time course of neuronal loss varied following lesion at different spinal levels, in all cases the majority of neurons in Clarke's nucleus had degenerated by 40 days after axotomy.

Storage temperature of the unbuffered rapid urease test

OBJECTIVES

The unbuffered rapid urease test (RUT) is an accurate, rapid, and inexpensive method for detecting Helicobacter pylori. However, it is generally recommended that the reagent be prepared daily. This prospective study was undertaken to evaluate the shelf life of our unbuffered RUT when stored at 4 and -20 degrees C.

METHODS

Ninety-five patients were studied. Three sets of antral (X2) and body (X1) biopsy samples were taken from each patient. The samples were subjected to histological examination, with the RUTs stored at 4 and -20 degrees C. The RUT tubes were examined at 1 and 15 min.

RESULTS

Fifty-six patients (59%) were infected with H. pylori as defined by histological examination. The reagent was classified according to storage time (group I, < or = 5 days; group II, > 5 days). The mean (SD) storage time of group I (n = 59) and group II (n = 36) was 3.2 (1.4) and 9.9 (5.0) days, respectively. At 15 min, the sensitivity of our RUT stored at 4 degrees C was significantly higher in group I than in group II (92 vs 47%). On the other hand, the sensitivity of our RUT stored at -20 degrees C remained consistently high in both groups (15 min: group I, 92%; group II, 100%). Our RUTs stored at 4 and -20 degrees C were highly specific in both groups.

CONCLUSIONS

Our RUT remains highly sensitive and specific when it is stored at 4 degrees C for up to 5 days. When the RUT is expected to be stored for a longer period of time, the bottles should be frozen at -20 degrees C.

The demography, clinical manifestations and natural history of human immunodeficiency virus (HIV) infection in an older population in Singapore

In this retrospective study, we report 43 cases (41 males and 2 females) of human immunodeficiency virus (HIV) infection in the Singapore population aged 50 years and above at first presentation. We found an increasing proportion of these older individuals among our HIV-seropositive patients; from 4.8% in 1991 to 16.7% by mid-1996. The mean age at presentation was 59.2 years (range 50 to 75 years). They were mainly heterosexuals (93%) and the majority (79.1%) were previously or currently married. Thirty-six (83.7%) patients had multiple sexual exposures to commercial sex workers. Nearly all had acquired the infection through the sexual route. The majority (76.7%) were symptomatic at presentation. Common clinical presentations were weight loss (72%), respiratory symptoms (60%) and oral candidiasis (56%). More than half (58.1%) of the patients had acquired immunodeficiency virus (AIDS) at the time of first presentation with a low median CD4 count of 17 cells/mm3. Pneumocystis carinii pneumonia and tuberculosis were the common AIDS-defining diseases. Survival in patients presenting with AIDS (median survival 3 months) is poorer compared to younger HIV-seropositive patients (< 50 years; median survival 1 year). No increase in age-related infection or malignancy was seen. Common causes of death were pneumonia and septicaemia. Physicians should consider HIV infection in older patients particularly when he/she presents with unexplained weight loss, respiratory symptoms and oral candidiasis. A history of high-risk sexual behaviour must be sought in all patients, including the elderly.

Drug-resistant tuberculosis in Singapore, 1995 to 1996

Singapore's tuberculosis incidence of 49 to 57 per 100,000 population for 1987 to 1996 presents a picture that is intermediate between developed and developing countries. The proportion of drug-resistant isolates has remained stable at 4.3% to 5.5% from 1992 to 1996 despite rising HIV rates. From 1995 to 1996, of the 199 consecutive drug-resistant isolates at the Central Tuberculosis Laboratory, 66% were mono-resistant, 22% dual-resistant and 12% resistant to more than two drugs. Isoniazid resistance was most prevalent, being found in 72% of isolates, followed by streptomycin resistance in 45%. Resistance to isoniazid and streptomycin (21%) was more common than to isoniazid and rifampicin, i.e. multidrug resistance (MDR) (14%). The small numbers indicated by the low overall prevalence of resistance and the predominance of single-drug resistance support the current initial choice of the standard short course with its three-drug initial phase. Of the 170 cases with matching National Tuberculosis Registry data, 72% of drug-resistant cases represented initial and 28% acquired resistance; testifying to the effectiveness of present day treatment regimens in suppressing resistance when compliance is assured. Case-control analysis using 244 drug-sensitive controls randomly selected from notifications in 1995 to 1996 showed an odds ratio for drug-resistance between subjects with a previous history and no previous history of tuberculosis of 2.47 (95% CI 1.40 to 4.37; P = 0.0007). With each increment in the number of episodes of tuberculosis experienced, there was a trend of resistance to progressively more drugs (P = 0.000004). This association remained even when a logistic regression model including all predictor variables was fitted. No associations were found with age, history of contact with tuberculosis, cavitary disease and, most notably, with human immunodeficiency virus infection. This study reaffirms that a history of previous tuberculosis should increase clinicians' index of suspicion for drug resistance, the urgency with which culture and sensitivity results are sought and the vigour with which patients are followed-up and compliance monitored.

A case report of visceral leishmaniasis in Singapore

Visceral leishmaniasis (Indian kala-azar) caused by infection due to the protozoan Leishmania donovani is endemic in the Indian subcontinent and adjoining regions. Prolonged fever, hepatosplenomegaly, anaemia and pancytopenia, in the appropriate setting, are important clinical markers towards the diagnosis. Diagnosis is established by blood film or bone marrow examination for Leishman Donovan (LD) bodies and/or culture. Treatment with sodium stibogluconate, pentamidine isethionate or even amphotericin B is usually successful. We report the first case of culture-proven visceral leishmaniasis in Singapore, in a 30-year-old Bangladeshi worker who presented with pyrexia of unknown origin (PUO). He had the classical constellation of symptoms and signs as mentioned above. Diagnosis was confirmed by culture on the Novy, NcNeal and Nicolle (NNN) medium. He was successfully treated with 20 days of pentamidine isethionate daily infusions at a dose of 2 mg/kg/day.

Clinical characteristics and natural history of human immunodeficiency virus infected patients seen at a general hospital in Singapore

The number of patients with human immunodeficiency virus (HIV) infection in Singapore has risen over the years. A considerable proportion of them present with acquired immunodeficiency syndrome (AIDS). In this study, we document the clinical characteristics and natural history of a consecutive series of 50 patients who were found to have HIV infection when they were seen at a tertiary care hospital. The majority were in the 30 to 49 age group and the most common mode of acquisition was heterosexual contact. The patients presented with a variety of symptoms to 11 different clinical departments. Fifty-eight per cent of the patients had AIDS-defining illnesses at presentation, with Pneumocystis carinii pneumonia being the most common. On follow-up, the most frequently occurring opportunistic infection that developed was Cytomegalovirus retinitis. Most patients had multiple subsequent admissions--for both AIDS-defining and non AIDS-defining conditions. The median CD4 count of the cohort at presentation was 72/mm3. The median survival was 399 and 822 days in those who had and those who did not have an AIDS-defining illness at presentation, respectively. Mortality was most commonly attributed to pneumonia. HIV infection has protean manifestations and patients may present to various specialty departments; hence, doctors need to be aware of the spectrum of disease in order to make a diagnosis.

Ophthalmic manifestations in human immunodeficiency virus infection in Singapore

The paper retrospectively reviews the spectrum of ophthalmic manifestations in human immunodeficiency virus (HIV) infection in Singapore between May 1995 and October 1996. One hundred and eighteen patients were examined for ocular abnormalities. Criteria for examination were 1) visual complaints, 2) absolute CD4 count of less than 50 cells/ul, 3) patients with acquired immunodeficiency syndrome-defining illness or 4) any relevant systemic illnesses which may have ocular involvement. Only 25 patients (21.2%) had visual symptoms. Eighteen patients (15.3%) had abnormalities associated with microvasculature. Forty-four patients (37.3%) had opportunistic infection involving the eye of which 37 were that of cytomegalovirus retinitis (CMVR). Seven patients (5.9%) had neuro-ophthalmic disorders. One patient presented with proptosis due to orbital lymphoma. Four patients (3.4%) had episcleritis and 3 patients (2.5%) had symptomatic dry eyes. It is still not known if episcleritis and dry eyes are associated with HIV infection or are coincidental. Fifty-one patients (43.2%) had no ocular pathology and remained so throughout the period of study. Nine patients (7.6%) had more than one pathology. The major cause of visual loss was due to ocular infections, with CMVR being most prevalent. Recognising the ophthalmic signs in HIV patients will facilitate early diagnosis. Prompt treatment of eye involvement can prevent or delay blindness, which is psychologically and functionally important to these patients.

Three new cases of leishmaniasis: implications for the Singapore medical community

Although visceral and cutaneous leishmaniasis are important clinical and public health problems worldwide, these diseases are not endemic in Singapore and the medical profession here has little opportunity to diagnose and manage these conditions. We report our experience with two patients with culture-proven visceral leishmaniasis and one with histologically-proven cutaneous leishmaniasis. The patients with kala-azar were migrant workers from countries in which the disease is endemic. The patient with proven cutaneous leishmaniasis (and another who was diagnosed to have the condition clinically) had entered the jungles of an endemic area. With increasing travel on the part of Singaporeans along less well-trodden paths to exotic destinations as well as the burgeoning traffic of migrant workers from less developed countries, doctors in Singapore will continue to see diseases such as leishmaniasis.

Travel medicine: a perspective on the emerging problem of travel-related infections

Travel Medicine has come a long way since it was started in the 1980s. Today, with the advances in electronic communications and efficient international travel, the demand for up-to-date information on international health situation is more urgent than before. Disease outbreaks can be updated and be available immediately across to the whole world in a matter of hours via the Internet. Travel medicine specialists no longer can give the excuse that they are unaware of such a situation because it is posted all over the net. Advances in vaccine development and the work of international agencies like the World Health Organization and the Centres for Disease Control have helped further the strategies and the knowledge we have in travel health risks. For the traveller, this means that they should no longer be travelling to a destination without knowing the health hazards and without taking the appropriate prophylaxis and precautions.

Dislodgment of catheter during arterial cannulation: a case report

Invasive blood pressure monitoring is important in medical practice, especially for hemodynamic monitoring of the critically ill. Catheter dislodgment is a rarely reported complication. We herein report a catheter dislodgment complication during the procedure of arterial cannulation.

Nucleic acid technology and infectious diseases

The past decade has witnessed an explosion in the knowledge of microbial genetics, pathogenesis, and antimicrobial resistance as a result of advances in molecular technology. This has brought important breakthroughs in the management of patients with infectious diseases, as organisms that had previously been difficult to demonstrate in vitro can now be detected by molecular techniques such as the polymerase chain reaction. Not only is rapid diagnosis now possible, but old diseases of uncertain aetiology have been found to have an infective origin, for instance, Whipple's disease. Molecular technology has also contributed greatly to epidemiological studies of outbreaks, understanding antimicrobial resistance, developing new antimicrobial agents, the in vitro synthesis of immunomodulators, production of vaccines, and gene therapy. The limitations of these latest technologies, however, need to be remembered so that they yield meaningful information for patient care.

Shelf life of unbuffered rapid urease test

BACKGROUND

Unbuffered rapid urease test (RUT) is an accurate and inexpensive method to detect Helicobacter pylori. However, the test is not always readily available because the reagents must be mixed freshly or stored at -20 degrees C after mixing. From our experience, storage at 4 degrees C for less than 6 days seemed to have no effect on the test's accuracy. This prospective study was undertaken to evaluate the shelf life of our unbuffered RUT.

MATERIAL AND METHODS

Forty-five patients were studied. From all patients, two sets of antral biopsy (X2) and body biopsy (X1) were taken. One set was subjected to histological examination; the other set was placed into a single capped Eppendorff tube for RUT. The tube was examined for any color change at 1 and 5 minutes.

RESULTS

Twenty-six patients (58%) were infected as defined by histological examination. The reagent was classified according to the storage time (group 1, < or = 5 days; group 2, > 5 days). The mean storage times of group 1 (n = 24) and group 2 (n = 21) were 3.1 (1.7 SD) days and 7.7 (1.2 SD) days, respectively. At 1 and 5 minutes, the sensitivity of group 1 was consistently higher than that of group 2 (1 minute, 61% versus 38%; 5 minutes, 92% versus 62%), and no false-positive result was observed in either group.

CONCLUSION

RUT remains highly sensitive and specific when it was stored at 4 degrees C for up to 5 days but should be discarded after that period.

Lower intestinal hemorrhage due to a dislodged metallic stent

A case of a 72 year old man is reported who developed a choledochoduodenal fistula due to distal biliary obstruction by a tumor of the papilla. A metal stent, introduced through this fistula into the common bile duct, dislodged and passed spontaneously with the feces. Plastic stents were then successfully inserted.

A survey of the long term outcome of elderly stroke survivors and the needs of their carers

A survey was conducted to assess the long term outcome of 60 elderly stroke survivors (mean age, 81.7 years). Of these patients, 48% died within one year of discharge and 79% of the mortality occurred in the first six months. Patients discharged to institutions after the initial stroke had a significantly higher risk of death in one year (relative risk=1.47) compared with those who were discharged home. For those who survived for a mean period of 18.6months, 72% (21/29) were institutionalised. This group had significantly worse functional status and mobility compared with those who were living at home. The caring of elderly stroke patients was considered a heavy burden for most carers at home or in institutions and the need for medical and social support was great.

Modulation of macrophage function for defence of the lung against Pseudomonas aeruginosa

Pseudomonas aeruginosa is a common respiratory tract pathogen in certain groups of compromised hosts, most notably those with cystic fibrosis. The pathogenicity of P. aeruginosa may depend in part upon its capacity to resist normal phagocytic cell clearance. We have recently shown that phagocytosis of P. aeruginosa by macrophages is a unique two-step process; binding is glucose-independent but ingestion occurs only in the presence of D-glucose or D-mannose. P. aeruginosa is the only particle we have found which is ingested by macrophages in a glucose-dependent manner. Since glucose is present in only negligible quantities in the endobronchial space, P. aeruginosa may be pathogenic by virtue of its capacity to exploit the opportunity presented in the lower airway to resist normal nonspecific phagocytic defences. The purpose of the studies reported here is to better understand the glucose-dependent phagocytosis of P. aeruginosa and to design novel therapies to facilitate phagocytic cell clearance of it from the lower respiratory tract. We have shown that phagocytosis of unopsonized P. aeruginosa depends upon facilitated transport of glucose into macrophages via the GLUT1 isoform. After transport into the macrophage, the glucose must be metabolized to trigger phagocytosis of P. aeruginosa; pretreatment with 2-deoxyglucose or 5-thioglucose abrogates glucose-dependent ingestion. We have recently demonstrated that pulmonary alveolar macrophages (as opposed to all other macrophage phenotypes studied) lack the capacity to transport glucose and to phagocytose unopsonized P. aeruginosa; however, after the cells have been cultured in vitro for 48 hours, they are able to perform both functions. Whereas most macrophages (such as peritoneal cells) primarily depend upon glycolysis for metabolic energy, pulmonary alveolar macrophages reside in a high oxygen tension environment and appear to utilize oxidative phosphorylation. Treatment of freshly explanted pulmonary alveolar macrophages with sodium azide (to poison oxidative respiration) dramatically enhances both glucose transport and glucose-dependent phagocytosis of P. aeruginosa. We are currently investigating the compromised phagocytic function of pulmonary alveolar macrophages and the mechanism by which azide enhances glucose transport and phagocytosis of P. aeruginosa. Although physiological measurements have indicated that glucose is removed from the endobronchial space by an active transport process of the lung epithelium, the types of glucose transporters that are expressed in the lung are as yet unknown. Using RT-PCR, we have amplified a product from human and murine lung RNA which has a high degree of homology with members of the sodium-dependent glucose transporter (SGLT) family. The ultimate goal of these studies is to design novel agents for enhancing the phagocytic function of pulmonary alveolar macrophages. Delivery of simple glucose by aerosol would not be effective because (i) it would be exported by sodium-dependent active transport and (ii) pulmonary alveolar macrophages lack the capacity to transport glucose. Various approaches for targeting glucose to alveolar macrophages by receptor-mediated endocytosis are under investigation.

Cervical ectopic pregnancy--a case report

Mdm LLG, a 28-year-old Chinese, a gravida 2 para I, presented at 9 weeks of pregnancy with painless vaginal bleeding. Ultrasound examination showed features of a cervical pregnancy. Hysterectomy was employed for treatment. Various recent conservative and surgical treatment modalities employed for this condition are discussed.

Provision of an out-of-hours blood banking service at a satellite hospital without blood bank staff

With limited health care resources and financial constraints, many hospitals have to reduce their service. Computer crossmatching has been accepted as a safe crossmatching procedure for patients without clinically significant alloantibodies. We report here a novel way of providing an out-of-hours blood banking service at a satellite hospital. The system is easy to introduce and can provide a safe transfusion service to small hospitals without stationing blood banking staff at these hospitals after regular working hours.

Validity of Bayesian forecasting programme in therapeutic drug monitoring of vancomycin in a surgical intensive care unit: a prospective evaluation

The objectives of this study were: (a) to assess the predictive performance of a 2-compartment Bayesian vancomycin forecasting programme in critically ill patients in the surgical intensive care unit, and (b) to show the applicability of the programme, which is based on parameters derived from Western population, in our local Asian population. Twenty critically ill patients were enrolled into the study programme. All patients received multiple-dose vancomycin for infections due to methicillin-resistant staphylococcus aureus (MRSA). The patients dosage regimen were optimised by entering a set of peak and trough vancomycin serum levels into a clinical computer program (MB; USC*PACK PC collection; University of Southern California, USA) by utilising a 2-compartment Bayesian population model. The correlation between observed and predicted serum peak and trough concentrations were evaluated for both the non-fitted and fitted models by linear regression analysis. There was a significant correlation between observed and predicted concentrations using the fitted model (r = 0.97, P < 0.05). There was no significant correlation of these concentrations in the non-fitted model (r = 0.8). This study shows that the Bayesian programme is able to accurately predict future vancomycin concentrations in our local Asian population. It is possible to optimise patients dosage regimens with the knowledge of two concentrations of vancomycin in order to achieve targeted therapeutic goals.

Evidence for genetic regulation of susceptibility to toxoplasmic encephalitis in AIDS patients

The frequency of HLA-DQ antigens in AIDS patients with toxoplasmic encephalitis (TE) were examined. HLA-DQ3 was significantly more frequent in white North American AIDS patients with TE (85.0%) than in the general white population (51.8%; P = .007, corrected P = .028) or randomly selected control AIDS patients who had not developed TE (40.0%; P = .016). In contrast, the frequency of HLA-DQ1 was lower in TE patients than in healthy controls (40.0% vs. 66.5%, P = .027), but this difference did not reach statistical significance when corrected for the number of variables tested (corrected P = .108 for the general white population). HLA-DQ3 thus appears to be a genetic marker of susceptibility to development of TE in AIDS patients, and DQ1 may be a resistance marker. These HLA associations with disease indicate that development of TE in AIDS patients is affected by a gene or genes in the HLA complex and that HLA-DQ typing may help in decisions regarding TE prophylaxis.

Tetanus in Singapore: report of three cases

Three cases of tetanus in Singapore are presented. One local resident had cephalic tetanus most likely secondary to otitis media and the other two, residents from surrounding Asean countries, had generalised tetanus. The portal of entry was a puncture wound on the foot in one patient and the ear in another. No portal of entry was identified in one patient. All three patients required tracheostomy, ventilatory support and intensive care management for periods ranging from 11 to 22 days. One patient died from complications of nosocomial septicaemia and one patient required prolonged rehabilitation. There was a questionable history of tetanus immunization in the Singapore resident whereas the other two patients who were foreigners had never received any immunization. Tetanus is an uncommon but important disease in Singapore. In spite of the availability of intensive care management, it continues to be a disease with significant morbidity and mortality. Early recognition and treatment of the disease are critical factors in determining the prognosis. This is a disease that may be largely prevented by adequate immunization.

Two cases of lower respiratory tract infection due to Chlamydia pneumonia in Singapore

Chlamydia pneumoniae, previously known as Chlamydia psittaci strain TWAR, causes both upper and lower respiratory tract infection. We report the first two cases of culture-positive Chlamydia pneumoniae lower respiratory infection in Singapore. Both patients had underlying fibrosing alveolitis and presented with a history of prolonged productive cough and fever. Chlamydia pneumoniae was isolated from the bronchoalveolar lavage fluid in the absence of other pathogens. The patients responded clinically to three weeks of oral doxycycline therapy. Infection due to Chlamydia pneumoniae should be considered when a patient with community-acquired pneumonia fails to respond to the usual standard antimicrobial therapy.

Neoglycoconjugates and their applications in glycobiology

Within the past two years new developments in neoglycoconjugate formation have increased the accessibility and usefulness of these probes for the analyses of glycan structure and function. This article reviews several simple chemical and enzymatic methods for tagging oligosaccharides with chromophores, biotin, peptides, proteins and lipids, and describes some representative applications of these neoglycoconjugates.

Use of prophylactic antibiotics in the prevention of infective endocarditis and prosthesis infection

In the field of antimicrobial therapy, few areas have created more debate and controversy than the subject of antibiotic prophylaxis for infective endocarditis. Firstly, there still exists considerable controversy about the efficacy of prophylactic antibiotics for prevention of bacterial endocarditis. Secondly, dental surgeons, orthopaedic surgeons, cardiologists and endoscopists have differing opinions regarding indications for pre-procedural prophylactic antibiotics against infective endocarditis. The British have a different set of recommendations from the Americans although the basic tenets on which these recommendations are founded are similar. This article summarises the updated recommendations issued by the American Heart Association (AHA) as well as those from the British Society for Antimicrobial Chemotherapy. A short discussion of the use of prophylactic antibiotics prior to endoscopy and surgery for patients with non-valvular prosthetic devices has been included in this paper. Practitioners should also be reminded that these recommendations are issued as guidelines and clinical judgement must be exercised when dealing with individual patients.

Pyrexia of unknown origin--approach to management

Pyrexia of unknown origin (PUO) remains one of the major diagnostic challenges for the clinician. Although infection, malignancy and collagen vascular disease remain the 3 most important causes of PUO, the relative importance of different disease entities within each of these major categories has changed because of improvements in serodiagnosis, culture techniques and radiologic imaging modalities. A detailed clinical history and meticulous physical examination remain the mainstay of the approach to management of patients with PUO. There is no set of "routine" investigations that patients with PUO should be subjected to. Instead, diagnostic testing should be individualised and guided by abnormalities found on clinical examination and simple laboratory testing. In patients in whom the diagnosis remains obscure in spite of extensive investigations and in whom the disease process is clearly progressive, judicious use of narrow spectrum anti-microbial therapy may be warranted. In the majority of the other patients who remain stable, careful clinical observation for new symptoms and signs are advised in the place of multiple courses of antimicrobials.

Analytical and preparative separation of anionic oligosaccharides by weak anion-exchange high-performance liquid chromatography on an inert polymer column

The use of ammonium formate buffers for analytical and preparative weak anion-exchange high-performance chromatography of anionic sugars is described. The method can be used for structures containing sulfate, phosphate, sialic acid, and uronic acid moieties. Excellent separation of the anionic sugars was achieved from pH 5.5 to 9. In contrast to silica matrix columns the polymer matrix column used can tolerate a wide range of pH values for the eluting buffer and it does not shed material into the eluent. The use of a single volatile buffer avoids additional purification steps to recover separated sugars suitable for further structural and functional analyses.

Recognition of carbohydrate by major histocompatibility complex class I-restricted, glycopeptide-specific cytotoxic T lymphocytes

Cytotoxic T cells (CTL) recognize short peptide epitopes presented by class I glycoproteins encoded by the major histocompatibility complex (MHC). It is not yet known whether peptides containing posttranslationally modified amino acids can also be recognized by CTL. To address this issue, we have studied the immunogenicity and recognition of a glycopeptide carrying an O-linked N-acetylglucosamine (GlcNAc) monosaccharide-substituted serine residue. This posttranslational modification is catalyzed by a recently described cytosolic glycosyltransferase. We show that glycosylation does not affect peptide binding to MHC class I and that glycopeptides can elicit a strong CTL response that is glycopeptide specific. Furthermore, glycopeptide recognition by cytotoxic T cells is dependent on the chemical structure of the glycan as well as its position within the peptide.