Telementored laparoscopic cholecystectomy: a pilot study

Few laparoscopic surgical experts exist relative to the number of surgeons needing training in laparoscopic surgical techniques. This study tested application of telemedicine technology in the mentoring of surgeons during laparoscopic cholecystectomy. Our Surgical Telementoring Suite provided real-time audio and video telecommunication to the operating room. Data points for telementored laparoscopic cholecystectomy (TLC, n = 6) were compared to age and sex-matched controls having standard laparoscopic cholecystectomy (SLC, n = 6) with mentors physically present in the operating room. TLC data were also compared between cases performed with a staff surgeon and resident as mentorees (SRM, n = 3), versus two residents as mentorees (RRM, n = 3). Data were analyzed with chi-square testing. The level of statistical significance was set at p < 0.05. No major operative complications occurred in either group (p > 0.05). Total operative times were similar (92.2 +/- 18.4 minutes SLC vs. 94.7 +/- 25.3 minutes TLC, p > 0.05). Additional data compared between SRM and RRM groups included time to establishment of a pneumoperitoneum of 12-15 mm Hg (7.0 +/- 6.1 minutes SRM vs. 6.7 +/- 2.9 minutes RRM), time to placement of all four trocars (13.0 +/- 3.6 minutes SRM vs. 10.3 +/- 3.1 minutes RRM, time to isolation and proximal clipping of the cystic duct (38.0 +/- 12.1 minutes SRM vs. 55.7 +/- 29.0 minutes RRM), and time to removal of the gallbladder (77.3 +/- 25.4 minutes vs. 77.7 +/- 27.5 minutes RRM). For all data points, p > 0.05. We conclude that telementoring is a safe, effective method for teaching the techniques of LC. This is true for operating teams composed of surgical residents, with or without staff surgeons present.

Prolonged storage of frozen unbuffered rapid urease test

Unbuffered rapid urease test (RUT) is an accurate, rapid, and inexpensive method of detecting Helicobacter pylori. However, it is generally recommended to prepare the reagent daily. This prospective study was undertaken to evaluate the shelf-life of our unbuffered RUT at -20 degrees C. Two sets of antral biopsies (X2) and body biopsies (X1) were taken from all patients. They were subjected to histologic examination and RUT stored at -20 degrees C. We studied 303 patients. One hundred seventy-nine (59%) were infected as defined by histologic examination. The reagent was classified according to the storage time (group I, 0-30 days [n = 109]; group II, 31-60 days [n = 63]; group III, 61-90 days [n = 80]; and group IV, tau91 days [n = 51]). There was an excellent agreement between the histologic examination and the RUT of the four groups (kappa coefficient: group I, 0.88; group III, 0.80; group III, 0.87; group IV, 0.88). The sensitivity of our RUT in groups I, II, III, and IV were 92%, 92%, 91%, and 89%, respectively. The corresponding specificity were 97%, 88%, 97%, and 100%. Our RUT remains highly sensitive and specific when it is stored at -20 degrees C for 4 months.

Case report of Staphylococcus lugdunensis native valve endocarditis and review of the literature

INTRODUCTION

Coagulase-negative staphylococci, commonly Staphylococcus epidermidis, cause 5% of native valve endocarditis. We describe a case due to Staphylococcus lugdunensis, a coagulase-negative staphylococcus identified in 1988, as a first report in Southeast Asia. It was previously misidentified as S. aureus because it is sometimes slide coagulase positive, but always tube coagulase negative, resulting in its delayed recognition as a pathogen. We also reviewed 36 other cases reported in the English literature from 1988 to 1999.

CLINICAL PICTURE

Our patient was admitted 3 times over 4 months for unresolved weight loss and fever before the coagulase-negative staphylococcus bacteraemia was eventually considered significant.

TREATMENT AND OUTCOME

He was treated with 4 weeks of high-dose intravenous penicillin and 2 weeks of gentamicin and did not require urgent valve replacement.

CONCLUSION

A positive blood culture of coagulase-negative staphylococcus is not always a contaminant. S. lugdunensis can cause aggressive native valve endocarditis resulting in high mortality, especially without surgical intervention.

Failure of routine HIV-1 tests in a case involving transmission with preseroconversion blood components during the infectious window period

CONTEXT

Current screening practices for blood donations have been successful in reducing human immunodeficiency virus (HIV) transmission through receipt of contaminated blood products. However, HIV-infected blood donations made prior to seroconversion and before high levels of viral replication occur could test negative using both serologic antigen and antibody tests. Testing based on nucleic acid amplification (NAT) is being implemented to screen for HIV-infected blood donated during this period, yet the issue of single vs minipool donation screening remains unresolved.

OBJECTIVES

To determine HIV-1 genetic linkage between virus in 2 HIV-1-infected recipients of blood components and virus in the donor, who was HIV antigen and antibody negative at the time of donation; to screen the blood donor's plasma with HIV NAT assays, including those currently proposed for use in US blood donation screening.

DESIGN AND SETTING

Case study conducted in October 1997 involving the Communicable Disease Centre, Singapore General Hospital, and the Singapore Blood Transfusion Service, Singapore.

SUBJECTS

The blood donor and the 2 recipients of donor platelets and red blood cells.

MAIN OUTCOME MEASURES

Genetic analysis of the HIV-1 p17 coding region of gag and the C2V5 region of env to determine the genetic relatedness of virus from the donor and recipients; reactivity in quantitative and qualitative assays, and reactivity in donor screening HIV NAT assays in single donation and minipool screening contexts.

RESULTS

Direct DNA sequencing demonstrated identical HIV-1 subtype E viral sequences in the donor and recipients. Based on comparisons of a qualitative and quantitative assay for HIV-1 RNA levels, a low level of viremia (range, 5-39 copies/mL in plasma) was estimated to be in the donor's undiluted blood at the time of donation. Additional testing using donor-screening NAT assays showed consistent detection of HIV RNA in the undiluted donor plasma whereas detection was inconsistent at the 1:16 and 1:24 dilution levels currently used in minipool screening of blood donations in the United States.

CONCLUSIONS

Transmission of HIV from a blood donor to a platelet recipient and a red blood cell recipient occurred in the preseroconversion infectious window period. The viral load in the implicated donation was estimated to be less than 40 copies/mL of plasma. Current US minipool HIV NAT screening protocols may not be sufficiently sensitive to detect all infectious window-period donations. JAMA. 2000;284:210-214

Stereotactic brain biopsies in AIDS patients--early local experience

AIM

To assess the usefulness of stereotactic brain biopsies in AIDS patients with cerebral lesions in Singapore.

METHODS

A total of 10 patients with AIDS and cerebral lesions underwent stereotactic brain biopsies in the Department of Neurosurgery, Tan Tock Seng Hospital (TTSH) between September 1997 and September 1998. The patients were referred from the Communicable Diseases Centre (CDC), TTSH. These patients either failed a trial of therapy for toxoplasmosis encephalitis (TE) or had CT/MRI scans which did not suggest TE. Four were CT-guided and six were MRI-guided stereotactic biopsies. The Radionics Cosman-Robert-Wells (CRW) stereotactic apparatus was used for all cases.

RESULTS

The male to female ratio was 9:1. Histological diagnosis from biopsy was lymphoma (5), metastatic adenocarcinoma (1), TE (1), abscess (1), encephalitis (1) and granulomatous tissue (1-presumed tuberculosis).

CONCLUSION

The early experience is that stereotactic brain biopsy is useful in patients with AIDS and cerebral lesions. The etiology is confirmed in the majority of cases and impacts on management decisions and prognostication.

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.