Improvement for the production of clavulanic acid by mutant Streptomyces clavuligerus

AIMS

To improve the production of clavulanic acid through the development of strains, the selection of a production medium and a pH shift strategy in a bioreactor.

METHODS AND RESULTS

Streptomyces clavuligerus mutant 15 was selected by antibacterial activities. As a result of pH control in a 2.5 l bioreactor, the highest productivity (3.37 microg x ml(-1) x h(-1)) was obtained at a controlled pH of 7.0.

CONCLUSIONS

The highest level of production obtained was an increase of about 36% compared with a non-controlled pH. When the production of clavulanic acid reached the maximum level, the pH was shifted from 7.0 to 6.0 for reduction in decomposition rate. The maximum concentration of clavulanic acid was maintained for 24 h as a result of the pH shift control, and a significant reduction in the decomposition of clavulanic acid was obtained.

SIGNIFICANCE AND IMPACT OF THE STUDY

Clavulanic acid decomposition was considerably reduced as a result of the pH shift control. The results of this study can be applied for the efficient production of beta-lactamase inhibitory antibiotics.

Hemodynamic effects of a combination of octreotide and terlipressin in patients with viral hepatitis related cirrhosis

BACKGROUND

Terlipressin or octreotide given alone has been used as the first-line pharmacological treatment for acute variceal bleeding. In portal hypertensive animals, pre-infusion of octreotide followed by the addition of terlipressin has an additive or complementary effect on splanchnic hemodynamics. The current study was aimed at evaluating such a combination treatment in patients with cirrhosis and portal hypertension.

METHODS

Patients were randomly assigned to receive either a placebo (n = 11) or an intravenous infusion of octreotide 100 microg/h after an initial bolus of 100 microg (n = 13). Thereafter, each patient received an intravenous injection of terlipressin 2 mg. Hemodynamic values were measured basally, 30 min after octreotide or placebo, and 60 min after terlipressin.

RESULTS

Placebo administration did not affect any of the hemodynamic values. Terlipressin administration resulted in expected changes in hepatic venous pressure gradient, hepatic blood flow and systemic hemodynamics. In contrast, octreotide administration significantly decreased hepatic blood flow but did not affect other hemodynamic values. After terlipressin administration, significant hemodynamic changes were observed that were similar to the hemodynamic changes with terlipressin alone. The magnitude of changes in hepatic venous pressure gradient, cardiac index and systemic vascular resistance were no different between the two groups of patients. The heart rate was significantly lower in patients receiving octreotide plus terlipressin than those receiving terlipressin alone.

CONCLUSION

The current study showed that a combination of octreotide and terlipressin did not exert an additive effect in reducing hepatic venous pressure gradient in patients with cirrhosis. In addition, the systemic hemodynamic changes were comparable between the two groups.

Leukopenia and thrombocytopenia in hemodialysis patients with hepatitis B or C virus infection and non-hemodialysis patients with hepatitis cirrhosis

AIMS

To investigate the relation of leukopenia and thrombocytopenia in hemodialysis (HD) patients with hepatitis C virus (HCV) infection.

MATERIALS AND METHODS

The study included 86 HD patients with hepatitis B surface antigen-negative and hepatitis C antibody-negative, 28 HD patients with hepatitis C antibody-positive, 22 HD patients with hepatitis B surface antigen-positive, 78 non-HD patients with hepatitis B-induced liver cirrhosis and 38 non-hemodialysis patients with hepatitis C-induced liver cirrhosis. The following parameters were checked: anti-HCV, hepatitis B surface antigen, hemoglobin, hematocrit, white blood cells, platelets, calcium, phosphate, iron, ferritin, albumin, globulin, aspartate transaminase (AST), alanine transaminase (ALT) and C-reactive protein. The history of blood transfusions, medications, erythropoietin doses and adequate dialysis (KTNV) for 6 consecutive months was also recorded from charts.

RESULTS

The HD patients with positive serum anti-HCV and non-HD patients with hepatitis B- or C-induced liver cirrhosis had higher prevalences of leukopenia (39.3%, 43.6% and 50% vs. 15.1%; p < 0.001) and thrombocytopenia (67.9%, 89.7% and 81.6% vs. 34.9%: p < 0.001) than HD patients with serum anti-HCV(-)HbsAg(-). The WBC (4,432 +/- 1,394, 4,792 +/- 2,263 and 4,624 2,446 vs. 5,590 +/- 1,500/mm3; p < 0.001) and platelet counts (140 +/- 45, 80 +/- 50 and 89 +/- 65 vs. 186 +/- 62 x 10(3)/mm3; p < 0.001) of HD patients with positive serum anti-HCV and non-HD patients with hepatitis B- or C-induced cirrhosis were also lower than HD patients without anti-HCV antibody. The liver cirrhosis patients had more thrombocytopenia than the HD patients with anti-HCV(+). The WBC and platelet counts did not vary between HD patients with HbsAg(+) and HD patients with anti-HCV(-)HBsAg(-). The durations of HD, hepatitis and liver cirrhosis were not related to the leukopenia or thrombocytopenia (p > 0.05).

CONCLUSIONS

HCV infection associated with leukopenia and/or thrombocytopenia in HD patients is as common as in non-HD patients with liver cirrhosis. This may be due to the direct effect of hemopoiesis rather than the hyperspleenism of liver cirrhosis patients. There is a need for further prospective investigation to ascertain the clinical significance of leukopenia and thrombocytopenia in HD patients with anti-HCV(+). The prevalence of leukopenia and thrombocytopenia was higher in HD patients with hepatitis C than in HD patients with hepatitis B and HD patient without hepatitis.

Effect of geminivirus infection and Bemisia infestation on accumulation of pathogenesis-related proteins in tomato

The whitefly, Bemisia tabaci biotype B, has been shown to cause pathogenesis-related (PR) proteins to accumulate in plants as a result of direct feeding, but their specific role in plant defensive systems is unclear. Our objective was to compare accumulation of tomato PR proteins (beta-1,3-glucanase, chitinase, peroxidase, P2 and P4) in response to whitefly, with or without tomato mottle virus (ToMoV) infection. Tomato PR protein response was measured over time in plants divided into three treatments: uninfected controls (with or without whiteflies) and plants infested with viruliferous (ToMoV) whiteflies. Five- to six-leaf plants were infested with approximately 5 adult whitefly per leaf. Plants were sampled prior to whitefly infestation and at 14, 28, 42, and 56 days. By 56 days, plants infested with viruliferous whiteflies had significantly more eggs (2.5-fold) and nymphs (4.5-fold) than plants with nonviruliferous whiteflies. A significant increase in the enzymatic activity of all measured PR proteins, as compared to control plants, was only seen in viruliferous whitefly-infested plants. No significant difference was observed in enzyme activities between the uninfected control plants either with or without whiteflies. The greatest differences for all PR proteins assayed were observed 42 days after treatment initiation. Protein blot analyses showed that the differences in PR protein activities among the treatments were due to changes in specific enzyme levels within the plant and were associated with concomitant increases in levels of P2 and P4 PR proteins. Under our experimental conditions, it is clear that PR protein response is much more intense when it is attacked by whiteflies carrying ToMoV than by whitefly alone.

Knowledge and attitudes of Korean parents towards their son's circumcision: a nationwide questionnaire study

OBJECTIVE

To evaluate knowledge about the foreskin and circumcision, and to understand the attitudes of parents to circumcision in Korea, where circumcision in childhood is widely practised with no particular religious or medical background.

SUBJECTS AND METHODS

A nationwide study involving questionnaires was conducted on 5500 parents with at least one son attending elementary school. Responses were obtained from one of the parents.

RESULTS

The response rate was 76.1% (4183); circumcision was most common in boys when aged 11 years, followed by neonatal circumcision. Of the parents, 91.3% believed that circumcision is necessary, while 2.1% believed it to be unnecessary. The principal reasons given for circumcision were 'to improve penile hygiene' (82.4%), followed by 'to improve future sexual potency' (7.5%). Among those who did not believe circumcision to be necessary, the most common reason was the expectation of spontaneous retraction of the prepuce with age (55.1%). Most (88.4%) of the parents believed that smegma is not a clean material, and is infected by microorganisms. Most parents (80.6%) thought that circumcision would prevent genital tract infection of the future spouse. Peer pressure was one of the most influential factors in deciding upon circumcision; 41.9% of the parents were anxious that their child might be ridiculed by his peer group unless he was circumcised, while 27.4% of the parents believed that their child might be ridiculed if he was circumcised. Mothers were more positive about circumcision than fathers (P < 0.05). Parents with a higher education and higher socio-economic status were also more positive about circumcision (P < 0.05). Mothers were prone to emphasize improved sexual potency (P < 0.05). There was no significant difference in response between urban and rural areas.

CONCLUSION

This study indicates that common beliefs held by parents about the prepuce or circumcision differ significantly from current medical knowledge, and these beliefs have a major influence on the practice of circumcision in Korea. More clinical research on the natural history of the foreskin is needed, and it is critical that both children and parents are informed about the potential benefits and disadvantages of circumcision.

Effect of formaldehyde on the expression of adhesion molecules in nasal microvascular endothelial cells: the role of formaldehyde in the pathogenesis of sick building syndrome

BACKGROUND

Formaldehyde is associated with sick building syndrome (SBS), a set of diffuse and irritative symptoms predominantly involving the eyes and the respiratory tract. However, its pathophysiological mechanism in SBS has not yet been clarified.

OBJECTIVE

In this study we investigated the effect of formaldehyde on the expression of adhesion molecules on human mucosal microvascular endothelial cells (HMMECs). Furthermore, we investigated the effect of formaldehyde on adhesiveness of HMMECs to eosinophils.

MATERIALS AND METHODS

HMMECs were incubated with various concentrations of formaldehyde (1 ng/mL-1 microg/mL) for 24 h, and the expressions of intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule (VCAM-1) on HMMECs were evaluated by flow cytometry. The change in the expression of ICAM-1 and VCAM-1 mRNA was then evaluated by reverse transcriptase polymerase chain reaction. To understand the role of formaldehyde in eosinophilic inflammation of the nasal mucosa, we examined the effects of formaldehyde on the adhesiveness between HMMECs and eosinophils by eosinophil adhesion assay.

RESULTS

Formaldehyde increased the surface expressions of ICAM-1 and VCAM-1 on HMMECs. Formaldehyde also induced ICAM-1 and VCAM-1 mRNA. In addition, the adhesiveness between HMMECs and eosinophils was also increased by formaldehyde.

CONCLUSION

These in vitro studies suggest that formaldehyde may play a role as the irritant of the nasal mucosa by increasing the expressions of adhesion molecules on HMMECs and by enhancing the adhesiveness between HMMECs and eosinophils.

Hepatitis C viral genotype influences the clinical outcome of patients with acute posttransfusion hepatitis C

Most patients with an acute infection of hepatitis C virus (HCV) will develop chronic hepatitis, and only about 15-20% of the cases will resolve spontaneously. The mechanism for the different outcomes in patients with acute HCV infection remains unclear. HCV genotype has been recognized as an important factor affecting the clinical course and outcome of chronic hepatitis C patients. In order to evaluate the role of HCV genotype in the clinical course and outcome of acute posttransfusion hepatitis C, 67 patients with acute posttransfusion hepatitis C from a prospective study of posttransfusion non-A, non-B hepatitis were enrolled. Thirty-nine patients (58.2%) were HCV genotype 1b. Among the 67 patients with acute posttransfusion hepatitis C, 53 (79.1%) progressed to chronic hepatitis. Significantly more patients with genotype 1b than non-1b genotypes developed chronic hepatitis (89.7% vs. 64.3%; P = 0.019). There was no significant difference in gender, mean age, amount of transfused blood, hepatitis symptoms, jaundice, incubation period, peak serum alanine transaminase, or serum HCV RNA titer between patients with HCV genotype 1b and non-1b infections. Patients who developed chronic hepatitis had a significantly greater incidence of genotype 1b infection (66.0% vs. 28.6%; P = 0.013) and a longer incubation period (7.3 weeks vs. 5.4 weeks; P = 0.052) than patients whose infection was resolved. Patients with a genotype 1b infection that resolved itself spontaneously all had an incubation period of less than 6 weeks. Multivariate logistic regression analysis revealed that genotype 1b and an incubation period > or = 6 weeks were significant predictive factors for the development of chronic hepatitis. Therefore, the HCV genotype can influence the outcome of patients with acute HCV infection.

Clinical Features of Neuroendocrine Lung Cancer

PURPOSE

This study was performed to investigate the clinical features of neuroendocrine lung cancer.

MATERIALS AND METHODS

We performed a retrospective review of the histopathology and clinical information of 21 patients diagnosed as having neuroendocrine lung cancer between 1995 and 1999.

RESULTS

Nineteen cases were male and 2 were female. The median age was 64 years (range: 45~80). Pathologic classification were atypical carcinoid (AC) in 2 cases, large cell neuroendocrine carcinoma (LCNEC) in 7 cases, and intermediate cell neuroendocrine carcinoma (ICNC) in 12 cases. Nine patients received tumor resection as first line therapy; adjuvant chemotherapy was given to 3 patients. Concurrent chemoradiotherapy was given to 1 patient. Six patients received palliative chemotherapy. The chemotherapy regimen included etoposide cisplatin in 5 cases and vinorelbine+cisplatin in 1 case. The median survival times were 11, 16 and 59 weeks for AC, LCNEC and ICNC, respectively. The estimated 2-year survival rates were AC 0%, LCNEC 22% and ICNC 31%.

CONCLUSION

Surgery may have a positive effect on survival in patients with early stage cansers. Further investigation is required to improve survival in cases of advanced stage cancer.

Extending the reading time increases the accuracy of rapid whole blood test for diagnosis of Helicobacter pylori infection

BACKGROUND

To evaluate the accuracy of two rapid whole blood tests (the BM-Test Helicobacter pylori and the QuikPac IV One Step H. pylori Whole Blood Test), and compare this to a conventional quantitative ELISA test (HEL-p TEST II).

METHODS

Helicobacter pylori status in dyspeptic patients was assessed by culture, histology, and rapid urease tests on biopsies from the antrum and corpus. The optimal cut-off value of the reading time for the rapid blood tests was determined by using the receiver characteristics operative (ROC) curves.

RESULTS

In the 141 patients examined, 89 were infected, 51 were not infected, and one was indeterminate (only positive in either urease test or histology). Areas under ROC curves were greater in the BM-Test compared with the QuikPac IV (0.948 vs 0.840, P < 0.01), with their most appropriate cut-off reading times at 360 and 395 min, respectively, rather than 10 min as suggested by the manufacturer. The sensitivity and specificity were 94.4% and 94.1% at 360 min, and 74.2 and 96.1% at 10 min for the BM-Test; 80.9, 76.5 at 395 min and 3.4 and 100% at 10 min for the QuikPac IV. The antibody titer of the quantitative ELISA test was negatively correlated with the reaction time of the two rapid blood tests in H. pylori-infected patients (P < 0.05, r=-0.3).

CONCLUSIONS

The BM-Test is an appropriate office-based test for diagnosing H. pylori infection in Chinese patients. Extending the reading time would facilitate the readability of rapid blood tests with a resultant increase in accuracy.

A progressive growing inflammatory pseudotumor of the liver

Inflammatory pseudotumors of the liver are very rare, and their etiology and pathogenesis remain unclear. The diagnosis is often difficult to make because these masses often mimic other lesions such as primary neoplasms, metastases or liver abscesses. Herein, we report a rare case of progressive growing hepatic pseudotumor in a 47-year-old man. The patient presented with body weight loss and general malaise. A series of radiological examinations showed the progressive growth of the hepatic tumor from 3.5 cm to 10.0 cm in diameter within 8 months. He underwent a right lobectomy of the liver, and the final diagnosis was proven by pathology. There were no complications in the post-operative course.

Effect of state workplace safety laws on occupational injury rates

The purpose of this study was to evaluate the effect of four common types of mandatory state-level workplace safety regulations on injury severity rates during the period 1992 to 1997 for the manufacturing sector. The full Poisson regression model showed safety committee regulations to have a highly significant reducing effect on injury rates, chi 2 (1, n = 3286) = 10.1774, P = 0.0014. Safety program regulations were significant at the alpha = 0.10 level, chi 2 (1, n = 3286) = 3.5676, P = 0.0589. The effect of insurance carrier loss control regulations in the full model was nonsignificant. However, insurance carrier loss control regulations were highly significant (alpha = 0.01) in the final reduced model. Targeting initiatives were nonsignificant in both the full and reduced models (alpha = 0.05). The study results are important to state and federal agencies considering adopting workplace safety regulations that are similar to the four types evaluated in this study.

ATP-induced mitogenesis is modulated by phospholipase D2 through extracellular signal regulated protein kinase dephosphorylation in rat pheochromocytoma PC12 cells

Extracellular ATP has been known to have many functions as a fast transmitter, and a co-transmitter, and to have morphogenic and mitogenic activity in neuronal cells. Although it was reported that ATP activates phospholipase D (PLD), the role of PLD versus the ATP function was unclear in neuronal cells. In this study, we investigated the role of PLD on the ATP-induced extracellular signal regulated protein kinase (ERK) activation and mitogenic effect in rat pheochromocytoma PC12 cells. In these cells ATP caused PLD2 activation and ERK phosphorylation, which was dramatically reduced by wild-type PLD2-overexpression but not by lipase-inactive-mutant PLD2-overexpression. The accumulation of phosphatidic acid (PA) by preincubating PC12 cells with propranolol (an inhibitor of PA phosphohydrolase) also decreased the ERK phosphorylation. Inhibition of phosphatases by okadaic acid or pervanadate completely blocked PLD2-dependent ERK dephosphorylation. In addition, ATP-stimulated thymidine incorporation was reduced by the overexpression of wild-type PLD2, but not by the overexpression of lipase-inactive-mutant PLD2. Okadaic acid pretreatment overcame the decrease of ATP-induced thymidine incorporation by PLD2 overexpression. Taken together, we suggest that PLD2 activity might play a negative role in ATP-induced ERK phosphorylation and mitogenic signal possibly through phosphatases.

Long-term evaluation of recombinant interferon alpha2b in the treatment of patients with hepatitis B e antigen-negative chronic hepatitis B in Taiwan

The effect of interferon (IFN) on hepatitis B e antigen (HBeAg)-negative chronic hepatitis B (CHB) has not been fully investigated in Chinese patients. We enrolled 58 HBeAg-negative CHB Chinese patients with hepatitis B viremia in Taiwan to evaluate the response to IFN. 30 patients received recombinant IFN 5 million units 3 times weekly for 6-10 months, and 28 patients who refused IFN treatment served as controls. Rates of virological response and biochemical response were higher in the treated group at the end of treatment (57% vs 18%, P = 0.006, and 73% vs 29%, P = 0.002, respectively). Both effects were superior in the treated group at 6 months after IFN withdrawal (virological: 30% vs 7%, P = 0.06; biochemical: 47% vs 7%, P = 0.002). Improvement of liver histological activities with persistently biochemical response was found in 65% of the treated patients. After a mean of 32 months' follow-up, virological response was rarely maintained (17% vs 4%, P = 0.228) but biochemical response was better in the treated group (27% vs 4%, P = 0.039). None of the treated patients but five controls developed severe complications of CHB during the follow-up period. A larger total IFN dosage or a younger age (< or = 40 years) were associated with 'sustained' virological response. Younger age and higher baseline alanine transaminase values (> or = 120 Ul(-1)) were related to 'sustained' biochemical response.

Resection of triple synchronous tumors--gastric adenocarcinoma, gallbladder adenocarcinoma and stromal tumor of the stomach

We herein report a rare case of triple synchronous tumors: gastric adenocarcinoma, gallbladder adenocarcinoma and stromal cell tumor of stomach, which were resected in the same operation. A 72-year-old male patient suffered from poor appetite and epigastric pain that radiated to his back for one month. Upper gastrointestinal endoscopy showed a gastric ulcer measuring 1.5 cm at the prepyloric area, which was proven to be adenocarcinoma by biopsy. A second tumor was found in the gallbladder, measuring 3 cm, by ultrasonography. On computed tomography, a third tumor about 2.5 cm in size was recognized posterior to the gastric high body and anterior to the pancreas. Given the presence of three tumors, he underwent a radical subtotal gastrectomy with Billroth-II gastrojejunostomy and simultaneous cholecystectomy. Pathological findings revealed gastric adenocarcinoma, gallbladder adenocarcinoma and stromal cell tumor of the stomach. The postoperative course was smooth.

Hereditary hemorrhagic telangiectasia: demonstration of portosystemic venous shunts using power Doppler sonography and sonographically guided percutaneous transhepatic portovenography

Hereditary hemorrhagic telangiectasia is a rare autosomal dominant inherited disease associated with vascular abnormalities, which may occur in any organ. Cases of hereditary hemorrhagic telangiectasia accompanied by intrahepatic portosystemic venous shunts, however, have rarely been described. We report a case of hereditary hemorrhagic telangiectasia in which intrahepatic portosystemic shunts were detected using power Doppler sonography and portovenography with percutaneous transhepatic contrast agent injection. On gray-scale sonography, the common hepatic artery was dilated, and dilated tubular structures mimicking dilated biliary tracts were found. Power Doppler sonography demonstrated the continuity of tortuous vascular channels connecting a branch of the right portal vein to a branch of the right hepatic vein. The dilated vascular channels and tributaries of the right hepatic vein showed a monophasic waveform pattern on spectral analysis. Portovenography showed a tangle of vascular structures connecting with a branch of the right hepatic vein.

The clinical features and prognostic factors of hepatocellular carcinoma patients with spinal metastasis

OBJECTIVE

Hepatocellular carcinoma is the most common malignancy in Taiwan, and spinal metastasis is a serious complication in cancer patients. In this study, we aimed to delineate the clinical features, evaluate the radiotherapy response and analyse the prognostic features in hepatocellular carcinoma subjects with spinal metastasis.

METHODS

From 1981 to 1997, 102 patients with spinal metastasis were enrolled, taken from the 5887 documented hepatocellular carcinoma patients treated at Taipei Veterans General Hospital. All the clinical and laboratory data were recorded, including: age; gender; liver biochemistry; tumour characteristics; Child-Pugh's score; performance status; number and location of vertebral metastasis; motor capacity; neurological symptoms and signs; response to radiotherapy of the spinal lesion; and survival. Prognostic factors in hepatocellular carcinoma patients with spinal metastasis were analysed using Cox's regression model.

RESULTS

The most common symptoms in hepatocellular carcinoma patients with spinal metastasis were lower back pain (74.5%), thoracic numbness (52.9%) and lower limb weakness (51.0%). Of the 102 patients, 84 received palliative radiotherapy using 3000 cGy for spinal lesions. Of these 84 patients, 32.1% showed a complete response, 26.2% a partial response and 41.7% a non-response to the radiotherapy. Multivariate Cox's regression analysis revealed that responsive radiotherapy (complete response + partial response) and good performance status (score <or= 2) were significant positive prognostic factors for survival in hepatocellular carcinoma patients with spinal metastasis.

CONCLUSIONS

Responsive radiotherapy can improve a hepatocellular carcinoma patient's quality of life by ameliorating the neurological condition and relieving pain, and can prolong survival in hepatocellular carcinoma patients with spinal metastasis.

Comparison of the response to the prone position between pulmonary and extrapulmonary acute respiratory distress syndrome

OBJECTIVES

To determine whether the response to the prone position differs between acute respiratory distress syndrome (ARDS) resulting from a pulmonary cause (ARDSp) and that from an extrapulmonary cause (ARD-Sexp).

DESIGN AND SETTING

Prospective observational study in a medical ICU of a university-affiliated hospital.

SUBJECTS

A consecutive series of 31 patients with ARDSp and 16 with ARDSexp within 3 days of onset of ARDS.

INTERVENTION

Prone position for at least 2 h.

MEASUREMENTS AND RESULTS

In ARDSp, compared with the supine position (121 +/- 49 mmHg), PaO2/FIO2 was not increased after 0.5 h but was increased after 2 h in the prone position (158 +/- 60 mmHg). In ARDSexp, compared with the supine position (106 +/- 53 mmHg), PaO2/FIO2 was increased after 0.5 h (155 +/- 91 mmHg), but was not further changed after 2 h. Marked oxygenation response (increase in PaO2/FIO2 > 40% from baseline) after 0.5 h was 23% in ARDSp and 63% in ARDSexp, and that after 2 h was 29% and 63%, respectively. Static respiratory compliance decreased in the prone position in ARDSexp (30 +/- 11 ml/cmH2O at baseline, 27 +/- 11 after 0.5 h and 25 +/- 9 after 2 h) but not in ARDSp. Consolidation score as determined on the first chest radiography taken in the prone position decreased to a greater degree in ARDSexp (-2.4 +/- 4.1) than in ARDSp (0.3 +/- 4.1).

CONCLUSION

Pulmonary ARDS and extrapulmonary ARDS in their early stages respond differently to the prone position with regard to the time course of oxygenation, respiratory mechanical behaviour, and radiographic change. These findings suggest that the early pathophysiology of ARDS differs according to the type of primary insult to the lung.

Pathogenic role of endothelin 1 in hemodynamic dysfunction in experimental acute pulmonary thromboembolism

The plasma endothelin-1 (ET-1) level is elevated in patients with acute pulmonary thromboembolism (APE). Whether ET-1 is a pathogenic mediator or a simple marker of APE is not known. We investigated the role of ET-1 in hemodynamic dysfunction in APE through evaluating the effects of ET(A) receptor antagonist in an experimental APE model. We also examined ET-1 expression in embolized lungs. In a canine autologous blood clot pulmonary embolism model, ET(A) receptor antagonist ZD2574 (10 mg/kg, intravenous; ZD2574 group; n = 6) or vehicle (control group; n = 5) was administered. Hemodynamic and gas exchange parameters and plasma levels of ET-1 were serially measured. Prepro-ET-1 mRNA expression and the distribution of ET-1 peptide in lung tissues were also examined. With ZD2574 pulmonary arterial pressure and pulmonary vascular resistance significantly decreased, and were lower compared with the control group. The decrease in cardiac output was also less in the ZD2574 group. Plasma ET-1 levels increased after embolization. Prepro-ET-1 mRNA expression increased in embolized lungs and ET-1 peptide expression also increased in embolized lungs, particularly in the muscular pulmonary arteries, compared with normal lungs. These findings suggest that ET-1 partially contributes to hemodynamic derangements of APE, and that ET(A) receptor antagonists might constitute a useful therapeutic tool for APE.

The prognosis of respiratory failure in patients with tuberculous destroyed lung

SETTING

The medical intensive care unit of a tertiary referral hospital.

OBJECTIVE

To determine the prognosis of patients whose lungs are damaged by previous and/or present tuberculosis infection and who have subsequently been presented with acute respiratory failure requiring mechanical ventilation.

DESIGN

A consecutive series of 38 patient cases with retrospective data analysis.

RESULTS

Pulmonary function test results for tests performed within the previous year were made available in 21 of the 38 cases (55%). These showed a mean (+/- SD) forced vital capacity (FVC) of 1.52 +/- 0.46 L (41.0 +/- 14.5% predicted), a forced expiratory volume/second (FEV1) of 0.77 +/- 0.18 L (29.3 +/- 13.6% predicted), and an FEV1/FVC ratio of 55.1 +/- 16.2%. The acid-fast bacilli (AFB) positive group had a significantly higher mortality and more severe lung destruction when compared with the AFB-negative group. Patients with positive AFB were significantly more hypocapnic than those with negative AFB (6.4 +/- 2.7 vs. 9.3 +/- 3.9 kPa, P = 0.020). In multivariate analysis, the level of PaCO2 on admission was identified as the only significant prognostic index (OR 0.76, 95%CI 0.60-0.96).

CONCLUSION

Patients with positive AFB smears or cultures may have higher mortality rates than those with negative AFB in the tuberculosis destroyed lung patients with acute respiratory failure. A higher PaCO2 measurement could indicate a better survival rate in this group of patients.

Infectious causes of chronic diarrhea

Chronic diarrhea can be seen in association with specific pathogens, usually parasites and occasionally some bacteria. This article reviews pathogens causing chronic diarrhea in immunocompetent individuals and provides a rational diagnostic approach.

Is submucosal epinephrine injection necessary before polypectomy? A prospective, comparative study

BACKGROUND/AIMS

Polyps of the gastrointestinal tract are usually removed due to their link to bleeding, obstruction and malignancy. However, complications may occur following polypectomy. The aim of this study was to assess whether submucosal epinephrine injection before polypectomy could reduce the incidence of bleeding and perforation.

METHODOLOGY

Between June 1997 and November 1999, patients with sessile polyps of the gastrointestinal tract found in our endoscopic unit were randomized to receive submucosal epinephrine injection (epinephrine group) or no injection (control group) before polypectomy. In the epinephrine group, epinephrine (1:10,000) was injected surrounding the stalk of the polyp until the mucosa was blanched and bulged. The patients were observed for complications in the following month.

RESULTS

A total of 120 patients with 151 sessile polyps were enrolled in this study. In the epinephrine group, 75 polyps (n = 68) were randomized to receive epinephrine injection before polypectomy. In the control group, 76 polyps (n = 61) underwent polypectomy without epinephrine injection. In both groups, there was no significant difference in clinical features including the sizes of the polyps and their stalks, the location of polyps and the pathological diagnosis. There were a total of nine episodes of post-polypectomy hemorrhage, two in the epinephrine group and seven in the control group (2/75 vs. 7/76) (P = 0.07). One case in the epinephrine group experienced delayed bleeding (4 days later). Immediate hemorrhage occurred less in the epinephrine group than that in the control group (1/75 vs. 7/76, P = 0.03). There was one case of perforation in each group.

CONCLUSIONS

Epinephrine injection prior to polypectomy is effective in preventing immediate bleeding.

Chronic hepatitis C virus infection associated with primary warm-type autoimmune hemolytic anemia

Autoimmune hematologic abnormalities are not well recognized in chronic hepatitis C virus infection. We demonstrate an unusual association between primary autoimmune hemolytic anemia and chronic hepatitis C virus infection. A 69-year-old woman who had a history of hepatitis C virus-related liver cirrhosis was found to have deteriorating anemia with reticulocytosis when admitted to the hospital. Laboratory work revealed both positive direct and indirect Coombs' tests, and warm-type immunoglobulin G against surface antigens of red blood cells. After prednisolone therapy, her anemia improved dramatically. To our knowledge, this is the first reported case of chronic hepatitis C virus infection linked with autoimmune hemolytic anemia in its natural course, not related to prior interferon treatment. Our report suggests that isolated autoimmune hemolytic anemia may be one of the unusual hematologic manifestations of chronic hepatitis C virus infection.