Acute necrotizing Meckel diverticulitis due to biliary enterolithiasis

BACKGROUND

Acute abdominal pain due to complicated Meckel's diverticulum is an unusual event. Even the presence of biliary enterolithiasis at the onset of inflamed congenital diverticulum has rarely been reported previously.

RESULTS

Despite this unusual presentation, an episode of gallstone passage through the biliary tract has not yet been described.

CONCLUSIONS

Whether the stones were primarily formed in the diverticulum as enterolithiasis, or secondary to gallstone passage is discussed. The complications of Meckel's diverticulum requiring surgical treatment are reviewed, focusing on the unusual finding of biliary stones in Meckel's diverticulum and the etiogenic mechanism of enterolithiasis.

Coherent high- and low-latitude climate variability during the holocene warm period

A faunal record of sea-surface temperature (SST) variations off West Africa documents a series of abrupt, millennial-scale cooling events, which punctuated the Holocene warm period. These events evidently resulted from increased southward advection of cooler temperate or subpolar waters to this subtropical location or from enhanced regional upwelling. The most recent of these events was the Little Ice Age, which occurred between 1300 to 1850 A.D., when subtropical SSTs were reduced by 3 degrees to 4 degrees C. These events were synchronous with Holocene changes in subpolar North Atlantic SSTs, documenting a strong, in-phase link between millennial-scale variations in high- and low-latitude climate during the Holocene.

Quantitative radioisotopic determination of histidine decarboxylase using high-performance liquid chromatography

We have developed a procedure for the accurate measurement of histidine decarboxylase in tissues expressing low levels of enzymatic activity. Briefly, histamine is enzymatically synthesized from [3H]-labeled histidine, followed by purification using high-performance liquid chromatography (HPLC) and quantitation by liquid scintillation counting. This method presents three advantages over previous techniques. First, prior to HPLC purification, excess precursor [3H]histidine is removed on an anion-exchange resin. Second, purification by HPLC is considerably more selective than that of classical cation-exchange gravity columns or organic solvent extractions. Finally, the accuracy of this method is improved by including non-radiolabeled histamine as internal standard, which is quantified by ultraviolet detection. This simple procedure allows highly sensitive and accurate determinations of histamine synthesis.

Amoxicillin-clavulanic acid versus cefotaxime in the therapy of bacterial infections in cirrhotic patients

BACKGROUND/AIM

Cefotaxime is considered the first-choice antibiotic for empirical treatment in cirrhotic patients developing bacterial infections. It has been suggested that amoxicillin-clavulanic acid could be an alternative to cefotaxime, particularly in patients developing bacterial infections while on prophylactic norfloxacin. The aim of the present study was to compare amoxicillin-clavulanic acid with cefotaxime in the treatment of bacterial infections in cirrhosis.

METHODS

Ninety-six hospitalized cirrhotic patients with suspicion of bacterial infection were prospectively included and randomized into two groups: one group (n=48) received amoxicillin-clavulanic acid, first intravenously 1 g-0.2 g every 8 h, and then orally 500 mg-125 mg every 8 h, and the other group (n=48) received intravenous cefotaxime 1 g every 6 h. Patients were stratified for previous prophylaxis with norfloxacin and ascitic fluid infection.

RESULTS

Sixteen patients were excluded from the analysis because bacterial infection was not demonstrated or because of secondary peritonitis. Therefore, 38 patients from the amoxicillin-clavulanic acid group and 42 from the cefotaxime group were finally analyzed. There were 24 ascitic fluid infections in each group. Infection resolution (86.8% vs 88%, 95% CI: -0.15 to 0.13, p NS), spontaneous bacterial peritonitis resolution (87.5% vs 83.3%, 95% CI: -0.15 to 0.24, p NS), duration of treatment, incidence of complications, time of hospitalization and hospital mortality were similar in both groups. Considering patients on prophylactic norfloxacin, infection resolution was also similar (100% vs 83.3%, 95% CI: -0.04 to 0.37, p NS). No adverse events were observed in either of the two groups. The cost of antibiotics was statistically lower in the amoxicillin-clavulanic acid group (p<0.001).

CONCLUSIONS

Amoxicillin-clavulanic acid is as effective as cefotaxime in the treatment of bacterial infections in cirrhotic patients, but is less expensive and can be administered orally. These results suggest that amoxicillin-clavulanic acid is an effective alternative to cefotaxime for the empirical treatment of bacterial infections in cirrhosis.

Molecular basis of NMDA receptor-coupled ion channel modulation by S-nitrosylation

Several ion channels are thought to be directly modulated by nitric oxide (NO), but the molecular basis of this regulation is unclear. Here we show that the NMDA receptor (NMDAR)-associated ion channel was modulated not only by exogenous NO but also by endogenous NO. Site-directed mutagenesis identified a critical cysteine residue (Cys 399) on the NR2A subunit whose S-nitrosylation (NO+ transfer) under physiological conditions underlies this modulation. In cell systems expressing NMDARs with mutant NR2A subunits in which this single cysteine was replaced by an alanine, the effect of endogenous NO was lost. Thus endogenous S-nitrosylation can regulate ion channel activity.

Is preoperative selection of patients with cystic adnexal masses essential for laparoscopic treatment?

STUDY OBJECTIVE

To analyze indications for preoperative selection of patients with cystic adnexal masses to be treated by laparoscopic surgery.

DESIGN

Retrospective analysis (Canadian Task Force classification II-2).

SETTING

University and military hospitals.

PATIENTS

Three hundred sixteen women with adnexal masses.

INTERVENTION

Before laparoscopy, 214 patients underwent evaluation (size of adnexal mass, ultrasonographic image, CA 125, suspicious clinical diagnosis); in 102 women laparoscopies were performed without taking these factors into account.

MEASUREMENTS AND MAIN RESULTS

In the first center 99% of women were treated by laparoscopic surgery. One (0.4%) tumor of low malignant potential detected by deferred biopsy was operated on. In the second center 98% of cases were performed laparoscopically. In 3.9% of women carcinomas were detected intraoperatively and were treated by laparotomy (p = 0.04).

CONCLUSION

Laparoscopy is appropriate management of cystic adnexal masses, with a very low risk of unintentionally operating an ovarian carcinoma if a thorough preoperative evaluation is conducted. Only in centers where surgeons have enough training to cope with ovarian cancer may this evaluation be deferred, since conversion to laparotomy should be considered a second therapeutic step, and not an incorrect indication for laparoscopy. In centers where surgeons have no such training, strict preoperative selection of patients is mandatory

Double outlet right ventricle with anterior and left-sided aorta and subpulmonary ventricular septal defect

Double outlet right ventricle (DORV) is a heterogeneous group of abnormal ventriculoarterial connections where, by definition, both great arteries (pulmonary artery and aorta) arise primarily from the morphologically right ventricle. This condition affects 1-1.5% of the patients with congenital heart diseases, with a frequency of 1 in each 10,000 live births. We report the case of an 18-day-old infant with DORV and extremely rare anatomical features, such as anterior and left-sided aorta and subpulmonary ventricular septal defect (VSD). In addition to the anatomic features, the role of the echocardiogram for guiding the diagnosis and the surgical therapy of this congenital heart disease are discussed.

Somatostatin alone or combined with emergency sclerotherapy in the treatment of acute esophageal variceal bleeding: a prospective randomized trial

Recent trials have shown that somatostatin (SMT) is as effective as sclerotherapy in the treatment of acute variceal bleeding and that the combination of both treatments is more effective than sclerotherapy alone. To assess whether the addition of sclerotherapy improves the efficacy of SMT alone, all patients admitted to our unit with gastrointestinal bleeding and with suspected cirrhosis received a continuous infusion of SMT (250 micrograms/h). Endoscopy was performed between 1 and 5 hours later, and patients with esophageal variceal bleeding were randomized to receive or not to receive sclerotherapy. In both groups, SMT infusion was continued for 5 days. Fifty patient admissions were allocated to each group. Therapeutic failure occurred in 21 cases of the SMT group and in 7 cases of the combined-therapy group (P =.002). Failure to control the acute episode occurred in 24% vs. 8% (P =.03) and early rebleeding in 24% vs. 7% (P =.03), respectively. Transfusional requirements were significantly higher in the SMT group, while the incidence of complications was lower (8% vs. 24%; P =.029). In the multivariate analysis, the presence of shock at admission and active bleeding during endoscopy were the variables that better predicted the failure of therapy with SMT alone. Mortality at 6 weeks was similar. These data demonstrate that the addition of sclerotherapy significantly improves the efficacy of SMT alone for the treatment of acute variceal bleeding, although it also increases the rate of complications. Patients with shock and those with active bleeding are more likely to benefit from this combined therapy.

Risk of a first community-acquired spontaneous bacterial peritonitis in cirrhotics with low ascitic fluid protein levels

BACKGROUND & AIMS

Long-term primary antibiotic prophylaxis of spontaneous bacterial peritonitis has been suggested to be useful in cirrhotic patients with low ascitic fluid protein levels. However, it is unlikely that all such patients need prophylactic treatment. The aim of this study was to identify the group of cirrhotic patients with low ascitic fluid protein levels at high risk of developing a first episode of spontaneous bacterial peritonitis during outpatient follow-up.

METHODS

One hundred nine cirrhotic patients with low ascitic fluid protein levels and without previous episodes of spontaneous bacterial peritonitis were followed up in an outpatient clinic.

RESULTS

Twenty-eight patients developed a first spontaneous bacterial peritonitis episode. In the multivariate analysis, serum bilirubin level (>3.2 mg /dL) and platelet count (<98.000/mm(3)) independently correlated with the risk of developing the first spontaneous bacterial peritonitis (P < 0.01 and P < 0.05, respectively). According to the median relative risk coefficient, a low-risk group (relative risk <1.09) and a high-risk group (relative risk >1.09) were established. The probability of developing a first spontaneous bacterial peritonitis episode at 1-year follow-up was significantly higher in the high risk-group (low-risk group, 23.6%; high-risk group, 55%; P < 0.01) as a consequence of a higher probability of the first community-acquired episode (13.7% vs. 47.6%, respectively, P < 0.01). One-year probability of survival was significantly lower in the high-risk group (low-risk group, 57.6%; high-risk group, 38%, P < 0.05).

CONCLUSIONS

Cirrhotic patients with low ascitic fluid protein levels (</=1 g /dL) and high bilirubin level and/or low platelet count are at high risk of developing a first episode of spontaneous bacterial peritonitis during long-term follow-up.

Intelligent control of a planning system for astronaut training

This work intends to design, analyze and solve, from the systems control perspective, a complex, dynamic, and multiconstrained planning system for generating training plans for crew members of the NASA-led International Space Station. Various intelligent planning systems have been developed within the framework of artificial intelligence. These planning systems generally lack a rigorous mathematical formalism to allow a reliable and flexible methodology for their design, modeling, and performance analysis in a dynamical, time-critical, and multiconstrained environment. Formulating the planning problem in the domain of discrete-event systems under a unified framework such that it can be modeled, designed, and analyzed as a control system will provide a self-contained theory for such planning systems. This will also provide a means to certify various planning systems for operations in the dynamical and complex environments in space. The work presented here completes the design, development, and analysis of an intricate, large-scale, and representative mathematical formulation for intelligent control of a real planning system for Space Station crew training. This planning system has been tested and used at NASA-Johnson Space Center.

A putative protein complex consisting of Ctf19, Mcm21, and Okp1 represents a missing link in the budding yeast kinetochore

We have established a one-hybrid screen that allows the in vivo localization of proteins at a functional Saccharomyces cerevisiae centromere. Applying this screen we have identified three proteins-Ctf19, Mcm21, and the product of an unspecified open reading frame that we named Okp1-as components of the budding yeast centromere. Ctf19, Mcm21, and Okp1 most likely form a protein complex that links CBF3, a protein complex directly associated with the CDE III element of the centromere DNA, with further components of the budding yeast centromere, Cbf1, Mif2, and Cse4. We demonstrate that the CDE III element is essential and sufficient to localize the established protein network to the centromere and propose that the interaction of the CDE II element with the CDE III localized protein complex facilitates a protein-DNA conformation that evokes the active centromere.

Infections caused by Escherichia coli resistant to norfloxacin in hospitalized cirrhotic patients

Selective intestinal decontamination with norfloxacin is useful to prevent bacterial infections in several groups of cirrhotic patients at high risk of infection. However, the emergence of infections caused by Escherichia coli resistant to quinolones has recently been observed in cirrhotic patients undergoing prophylactic norfloxacin. Our aim is to determine the characteristics of the infections caused by E. coli resistant to norfloxacin in hospitalized cirrhotic patients. One hundred and six infections caused by E. coli in 99 hospitalized cirrhotic patients were analyzed and distributed into two groups: group I (n = 67), infections caused by E. coli sensitive to norfloxacin, and group II (n = 39), infections caused by E. coli resistant to norfloxacin. The clinical and analytical characteristics at diagnosis of the infection were similar in both groups. Previous prophylaxis with norfloxacin was more frequent in group II (15/67, 22.4% vs. 32/39, 82%, P <.0001), as a result of a higher number of patients submitted to continuous long-term prophylaxis in this group, whereas previous short-term prophylaxis was similar in both groups. Infections were more frequently nosocomial-acquired in group II than in group I (17/67, 25.3% vs. 20/39, 51.2%, P =.01). The type of infections was similar in both groups: urinary tract infections 38 in group I and 24 in group II, spontaneous bacterial peritonitis 8 and 2, spontaneous bacteremia 4 and 4, and bacterascites 1 and 0, respectively (pNS). Mortality during hospitalization was similar in the two groups (4/67, 5.9% vs. 5/39, 12.8%, pNS). None of the E. coli resistant to norfloxacin were also resistant to cefotaxime and only one of them was resistant to amoxicillin-clavulanic acid. Prophylaxis with norfloxacin, usually continuous long-term prophylaxis, favors the development of infections caused by norfloxacin-resistant E. coli. Long-term antibiotic prophylaxis should therefore be restricted to highly selected groups of cirrhotic patients at high-risk of infection. Infections caused by E. coli resistant to norfloxacin show a severity similar to those caused by sensitive E. coli. No significant associated resistance between norfloxacin and the antibiotics most frequently used in the treatment of bacterial infections in cirrhotic patients has been observed.

Effect of atmospheric pollution on the respiratory system

Santiago de Chile has a high level of air pollution with ozone (O3), carbon monoxide (CO) and particles equal or smaller than 10 microns (PM10) usually exceeding the accepted standards. This situation should be noxious for the exposed population and particularly--in the case of O3 and PM10--for the respiratory system. However, such an effect is rather difficult to demonstrate and it depends on the type of population under study.

[Molecular diagnosis in an Argentinian family with multiple endocrine neoplasia type-1 (MEN-1)]

MEN-1 is a hereditary autosomal dominant syndrome characterized by the involvement of parathyroid glands, pancreatic islet cells and anterior pituitary gland. Today molecular genetics permit gene carrier analysis to compare the data obtained with the clinical biochemical tests. The twenty living members of the first, second and third generation of a family with MEN-1 were studied to determine the presence of genetic markers in MEN-1 loci 11q13, by linkage analysis and in affected individuals by biochemical tests and clinical examination. Two very informative polymorphic markers immediately flanking the MEN-1 gene on chromosome 11 band q13 were detected: PYGM and D11S987, haplotypes segregated by two members of the second generation, inherited from their father and two of the third generation: the affected one and one presymptomatic. The third generation had the affected member with renal stones and elevated PTH, PRL and glucagon. The presymptomatic carrier of MEN-1 allele showed elevated PTH. Among the members who inherited the normal allele we found one with elevated gastrin, one with elevated glucagon and one with elevated PTH, all asymptomatic. Of one Argentine family studied, molecular diagnosis allowed us to detect one presymptomatic carrier in the members at risk. As suggested by the available literature, accuracy of molecular diagnosis seems to make it the test of choice to exclude those members at risk for MEN-1 inheriting the normal allele.

Assay method for the carboxylic acid metabolite of clopidogrel in human plasma by gas chromatography-mass spectrometry

This paper describes a GC-MS method for the analysis of the carboxylic acid metabolite (SR26334, II) of methyl (+)-(S)-alpha-(o-chlorophenyl)-6,7-dihydrothieno[3,2-c]pyridine-5( 4H)-acetate hydrogensulfate (clopidogrel, SR 25990, I) in plasma and serum. The analytical procedure involves a robotic liquid-liquid extraction with diethyl ether followed by a solid-liquid extraction on C18 cartridges. The derivatization process was performed using n-ethyl diisopropylethylamine and alpha-bromo-2,3,4,5,6-pentafluoro toluene. A structural analogue (III) of II, was used as internal standard. The 1/X2; weighted calibration curve obtained in the range 5-250 ng/ml was well described by a quadratic equation. The extraction efficiency was better than 48% over the range studied; for the internal standard it averaged 51% at 50 ng/ml. Precision ranged from 3.6 to 15.8%, and accuracy was between 92 and 114%. Dilution has no influence on the performance of the method which could then be used to quantitate plasma samples containing up to 25000 ng/ml. The limit of quantification was 5 ng/ml. The method validation results indicate that the performance characteristics of the method fulfilled the requirements for assay methods for use in pharmacokinetic studies.

Parenteral antibiotic prophylaxis of bacterial infections does not improve cost-efficacy of oral norfloxacin in cirrhotic patients with gastrointestinal bleeding

OBJECTIVE

Selective intestinal decontamination with norfloxacin is useful in the prevention of bacterial infections in cirrhotic patients with gastrointestinal bleeding. However, bleeding cirrhotic patients with ascites, encephalopathy, or shock are at high risk to develop bacterial infections in spite of prophylactic norfloxacin. The aim of this study was to assess whether the addition of intravenous ceftriaxone could improve the efficacy of prophylaxis with norfloxacin in these patients.

METHODS

Fifty-six cirrhotic patients with gastrointestinal hemorrhage and ascites, encephalopathy, or shock were randomized into two groups: Group 1 (n = 28) received oral norfloxacin 400 mg/12 h for 7 days, and group 2 (n = 28) received norfloxacin plus intravenous ceftriaxone 2 g daily during the first 3 days of admission.

RESULTS

Ten patients were excluded because of community-acquired infection, surgery, or death within the first 24 h. The incidence of bacterial infections during hospitalization was 18.1% in group 1 and 12.5% in group 2 (p = NS). The incidence of severe infections (spontaneous bacterial peritonitis, bacteremia, or pneumonia) was also similar in both groups: 9% in group 1 versus 8.3% in group 2 (p = NS). There were no statistical differences between the two groups with respect to duration of hospitalization or mortality. The cost of antibiotic therapy (including prophylaxis and treatment of infections) was significantly higher in group 2.

CONCLUSION

These results suggest that the addition of intravenous ceftriaxone during the first 3 days of hospitalization does not improve the cost-efficacy of oral norfloxacin in the prevention of bacterial infections in cirrhotic patients with gastrointestinal bleeding and high risk of infection.

Effect of subcutaneous administration of octreotide on endogenous vasoactive systems and renal function in cirrhotic patients with ascites

Splanchnic and systemic arteriolar vasodilation plays an important role in ascites formation in cirrhosis. Octreotide produces splanchnic vasoconstriction, but the effects on systemic hemodynamics and renal function are controversial. This study evaluated the effect of subcutaneous octreotide administration on systemic hemodynamics, endogenous vasoactive systems, and renal function in cirrhotic patients with ascites. Twenty patients were included: 10 received octreotide 250 microg/12 hr subcutaneously (for five days), and 10 did not. No statistically significant changes were found in mean arterial pressure and cardiac rate. Octreotide induced a statistically significant decrease in plasma renin activity (P < 0.01), plasma aldosterone (P = 0.01) and plasma glucagon (P < 0.05). No significant variations were observed in other systemic vasoactive substances (nitric oxide and prostacyclin). Renal function was not modified in either group. In conclusion, in cirrhotic patients with ascites, subcutaneous octreotide administration decreases plasma glucagon, renin activity, and aldosterone without changing in systemic hemodynamics or renal function.

Infective complications after abdominal surgery in patients infected with human immunodeficiency virus: role of CD4+ lymphocytes in prognosis

Risk factors associated with surgical infections are related to many events that modulate the immune system and affect the surgical procedure. The aim of this study was to determine the influence of low CD4+ lymphocyte counts in 24 patients with human immunodeficiency virus (HIV) undergoing abdominal surgery. Blood samples were obtained, and the lymphocyte population was evaluated perioperatively, as was the nutritional status of the patient. All the patients received selective antibiotic prophylaxis depending on the surgical procedure performed: (1) clean surgery: splenectomies (n = 8); (2) clean-contaminated: cholecystectomy and biliary tract surgery (n = 8); and (3) contaminated: appendectomy (n = 8). Depending on their CD4 count, two groups were formed: one with 200 to 500 cells/ml (n = 11) and the other with < 200 cells/ml (n = 13). When surgical infection was suspected, surgical drainage and microbiologic cultures were undertaken. For statistical evaluation of the groups ANOVA and the chi-square test were used; p < 0.05 was considered significant. Altogether 14 patients (58.3%) had a wound infection, and the mean (+/- SD) CD4 count in those patients was decreased (221.7 +/- 75.1) compared with that of the 10 patients in the uneventful group (386 +/- 81.2). Surgical infection rates were 50% for clean procedures, 62.5% for clean-contaminated procedures, and 62.5% for contaminated surgery. The group of patients with CD4 counts of < 200 cell/ml had an increased incidence of surgical infection, regardless of the type of surgery (p = 0.002). Thus the surgical infection rates with HIV patients undergoing abdominal surgery are dramatically increased. The CD4 and subsequently depressed neutrophil populations increase the risk of surgical infection during major procedures regardless of the type of surgery performed.

Reliability of serum magnesium values during diabetic ketoacidosis in children

OBJECTIVE

To determine the prevalence of hypomagnesemia in diabetic children during diabetic ketoacidosis and following restitution of acid-base balance.

METHODS

Eight consecutive diabetic children, ranging in age from 8 to 16 years, hospitalized in the pediatric intensive care unit with diabetic ketoacidosis from October 1st. through December 31st, 1995. A control group of 33 metabolically stable diabetic children, and a control group of 30 healthy children. Both control groups were similar in composition regarding age and sex to the study group. None of the patients in the study group and none of the controls had Magnesium supplementation given to them during the study period.

MEASUREMENTS

Total serum Magnesium concentrations were measured from peripheral venous blood in all 71 patients. For the study group serum Magnesium was determined in a serial fashion: 1. upon admission in diabetic ketoacidosis 2. 24 hours after admission 3. 72 hours after admission

RESULTS

The prevalence of hypomagnesemia was 62.4% in patients with diabetic ketoacidosis, (Group 1), 25% in patients after partial correction of ketoacidosis, (Group 2), and none in patients after resolution of ketoacidosis, (Group 3). The prevalence of hypomagnesemia was 6% for the chronic, metabolically stable diabetic control group, (Group 4), but 0% for the non-diabetic control group, (Group 5). Average serum Magnesium levels were significantly lower (p less than 0.05), in patients admitted in diabetic ketoacidosis compared to those of both the diabetic and the non-diabetic control groups. Also average serum Magnesium levels were significantly lower (p less than 0.05), in patients with corrected diabetic ketoacidosis than those of the healthy control group. But there were no significant differences (p = 0.59263) in average serum Magnesium levels between the diabetic control group and the diabetic patients after resolution of ketoacidosis.

CONCLUSIONS

In this study the prevalence of hypomagnesemia was documented to be higher than the average described elsewhere for pediatric, adult, and coronary intensive care units. As hypomagnesemia is an indication of Magnesium depletion, we speculate that the transient hypomagnesemia detected in our study group is an expression of a state of Magnesium depletion that is masked by correction of acidosis and the Magnesium shifts associated with it. Consequently serum Magnesium values ought to be considered most reliable during and not after correction of diabetic ketoacidosis. Since Magnesium was not supplemented to any of our patients, the normalization of their serum values must be the result of: a. decreased glycosuria-related urinary losses b. cessation of acidosis-related urinary losses c. Magnesium shifts from intra to extracellular space The high prevalence of hypomagnesemia and the significant lower average serum Magnesium levels in children with diabetic ketoacidosis reveals the magnitude of the problem and the potential for Magnesium depletion that occurs in diabetic children.

Relationship between blood serotonergic variables, melancholic traits, and response to antidepressant treatments

The relationship between peripheral serotonergic variables, melancholic traits, and clinical improvement after antidepressant treatment was examined in 83 drug-free major depressive patients. Plasma serotonin (5-HT) concentrations was lower in untreated melancholic patients (1.00 +/- 0.11 vs. 1.84 +/- 0.28 ng/mL, p < 0.008; N = 40 and 43, respectively). A tendency was observed for plasma 5-hydroxyindoleacetic acid (p < 0.06), whereas platelet 5-HT and plasma tryptophan did not differ between groups. After blood sampling and clinical ratings, treatment began with fixed doses of 5-HT uptake inhibitors (clomipramine or fluvoxamine), monoamine oxidase inhibitors, or tianeptine, a 5-HT uptake enhancer. There was no significant difference in response rates between patients with and without melancholic traits. The relationship between the clinical response at 6 weeks (>50% reduction of baseline Hamilton score) and the pretreatment values of biochemical variables was examined. Responders had a lower pretreatment platelet 5-HT (530 +/- 36 vs. 664 +/- 50 ng/10(9) platelets, p < 0.03; N = 44 and 39, respectively). Patients with a platelet 5-HT concentration above 800 ng/10(9) platelets had a lower response rate than those below this value (p < 0.003). This difference was maximal in the subgroup of patients treated with 5-HT uptake inhibitors (N = 49). In this subgroup, the response rates of patients with 5-HT concentrations below and above the cutoff point were, respectively, 70% and 17% (p < 0.001). A pretreatment platelet 5-HT value above 800 ng/10(9) platelets had a predictive value for a negative response of 92%. These results suggest the presence of biochemical differences in the peripheral serotonergic system between melancholic and nonmelancholic patients. The inverse relationship between the pretreatment platelet 5-HT content and clinical response may be useful in the investigation of the relationship between the 5-HT system and antidepressant response.

Azidothymidine triphosphate determination using micellar electrokinetic capillary chromatography

There is a need to perform pharmacokinetic studies in the pediatric population utilizing antiretroviral drugs, which have shown effectiveness for the treatment of human immunodeficiency virus (HIV). In order to establish a relationship between efficacy and toxicity, we need to detect and quantitate these antiretroviral nucleosides and their metabolites at the intracellular level. Micellar electrokinetic capillary chromatography (MECC) was used for the separation of five nucleotides: cytidine triphosphate (CTP), adenosine triphosphate (ATP), thymidine triphosphate (TTP), guanosine triphosphate (GTP) and azidothymidine triphosphate (AZT-TP). Attomoles of these nucleotides were satisfactorily resolved in short run times with high peak efficiencies. In addition, nanoliters of sample volume were used to perform the analysis using ultraviolet (UV) detection at 254 nm.

Early microbiologic diagnosis of spontaneous bacterial peritonitis with BacT/ALERT

BACKGROUND/AIMS

Inoculation of ascitic fluid into conventional blood culture bottles is more sensitive than conventional culture in the diagnosis of spontaneous bacterial peritonitis. BacT/ALERT is an automated colorimetric microbial detection system that has been shown to be faster than conventional blood culture bottles in the diagnosis of bacteremia. The aim of the study was to compare the BacT/ALERT system with the conventional culture and the conventional blood culture bottles method in the diagnosis of spontaneous bacterial peritonitis.

METHODS

All the ascitic fluid samples from patients with cirrhosis hospitalized in our Department between September 1992 and May 1994 (n=1032) were prospectively evaluated. In all cases, an aliquot of ascitic fluid was sent for Gram's stain and conventional culture, and 20 ml were inoculated at the bedside into blood culture bottles: 10 ml into conventional blood culture bottles and 10 ml into BacT/ALERT.

RESULTS

Thirty ascitic fluid infections (23 spontaneous bacterial peritonitis and 7 neutrocytic ascites) and 20 bacterascites were diagnosed. Conventional culture was positive in 10/30 ascitic fluid infections (33.3%), conventional blood culture bottles in 22/30 (73.3%) (p<0.01 compared to conventional culture) and BacT/ALERT in 20/30 (66.6%) (p<0.05 compared to conventional culture, pNS compared to conventional blood culture bottles). The time elapsed for culture positivity was 43.4+/-34.2 h for conventional blood culture bottles and 13.3+/-9.2 h for BacT/ALERT (p<0.001). Thirteen of the 23 cases of spontaneous bacterial peritonitis (56.5%) were detected within the first 12 h with BacT/ALERT, as compared to only three (13%) with conventional blood culture bottles (p<0.03).

CONCLUSION

The automated system BacT/ALERT provides an earlier microbiologic diagnosis of spontaneous bacterial peritonitis than conventional blood culture bottles with similar sensitivity.