Development of a latex agglutination test for rapid identification of Escherichia coli

Escherichia coli, one of the most important human pathogens, is usually identified by a battery of biochemical tests that require overnight incubation. For rapid identification of Escherichia coli, a latex agglutination test (LAT) was developed. Rabbits were immunized with cell-surface antigens extracted from Escherichia coli CCRC 15481 with 4 M urea, and the affinity-purified antibodies were used to coat latex particles for the identification of the bacterium. The following gram-negative bacteria were used to evaluate the LAT: Escherichia coli (n = 761), Enterobacteriaceae other than Escherichia coli (n = 632), Aeromonas spp. (n = 21), Pseudomonas spp. (n = 75), Vibrio spp. (n = 18), and other bacteria (n = 64). The LAT had a sensitivity and specificity of 99.2 and 93.3%, respectively. If the LAT was used in conjunction with the tests of indole production or lactose fermentation, the specificity values for the identification of Escherichia coli increased from 93.3 to 98.8 and 98.7%, respectively. If the LAT, indole production, and lactose fermentation were used together for the identification of Escherichia coli, the sensitivity and specificity were 94 and 99.7%, respectively. Lactose fermentation could be detected by observing the colonies grown on selective media (e.g. MacConkey agar), and indole production could be analyzed simply by the spot indole test. Strains producing negative reactions (i.e. not identified as Escherichia coli) should be processed by the conventional procedures for identification. The present protocol integrating the LAT, indole production, and lactose fermentation for the identification of Escherichia coli offers considerable savings of time, manpower, and cost.

Comparison of a novel electro-Fenton method with Fenton's reagent in treating a highly contaminated wastewater

This study applied a novel electrochemical process called the Fered-Fenton method to treat a highly concentrated wastewater. By combining electrochemical reduction and chemical oxidation, the process can remove organic compounds and heavy metals in a batch reactor. A PVC-stabilizer processing wastewater was treated in this investigation owing to its high heavy metal concentration (Pb = 7,500 mg/l) and high organic concentration (COD = 11,000 mg/l). The major organic component was acetate. Direct anodic oxidation showed no effect on COD removal. Fenton's method only removed 36% of COD using 4,000 mg-Fe2+/l and 28,000 mg-H2O2/l dosage. In the Fered-Fenton process, about 89% of COD was removed with 2,000 mg-Fe3+/l and 28,000 mg-H2O2/l. Furthermore, the COD removal attained an efficiency of about 98% for 56,000 mg-H2O2/l used. Results presented herein demonstrate that the Fered-Fenton method is superior to direct anodic oxidation and Fenton's method in this case. Furthermore, the changes of the intermediate compounds including acetate, oxadate, and formate during the reaction were analyzed, which provided us with the information to propose degradation reactions of the wastewater in this system.

A seminal vesicle autoantigen of mouse is able to suppress sperm capacitation-related events stimulated by serum albumin

We studied the effect of a mouse seminal vesicle autoantigen (SVA) on BSA-stimulated functions of mouse sperm. Uncapacitated, capacitated, and acrosome-reacted stages of sperm were morphologically scored, and the cellular zinc content was examined cytologically in a modified Tyrode solution at 37 degrees C for 80 min. More than 85% of control cells remained uncapacitated. Addition of 0.3% SVA to the cell incubation did not affect the cell status. Approximately 65% of cells were capacitated in the incubation medium containing 0.3% BSA. Only 30% of the cells became capacitated after incubation with 0.3% BSA and 0.3% SVA together. The decapacitation effect by 0.3% SVA could be subdued by more than 3% BSA in the cell incubation. Whereas BSA did, SVA did not cause removal of Zn(2+) from sperm, but SVA could suppress the BSA effect. The tyrosine phosphorylated proteins in sperm were detected after incubation in a modified HEPES medium containing 0.3% BSA and/or 0.3% SVA at 37 degrees C for 90 min. Whereas BSA enhanced greatly, SVA did not cause phosphorylation of proteins in the range of M:(r) 40 000-120 000. The BSA-stimulated protein tyrosine phosphorylation could be suppressed by SVA in the cell incubation.

Diagnostic value of immunoglobulin G (IgG) and IgM anti-hepatitis E virus (HEV) tests based on HEV RNA in an area where hepatitis E is not endemic

Acute hepatitis E (AHE) has rarely been reported in industrialized countries, but the rate of seroprevalence of hepatitis E virus (HEV) antibodies (anti-HEV) is inappropriately high. The sensitivity and specificity of the assay used to test for immunoglobulin G (IgG) and IgM anti-HEV have not been well established in areas where hepatitis E is not endemic (hereafter referred to as "nonendemic areas"). We collected serum samples from 13 AHE patients, 271 healthy subjects, and 160 other liver disease patients in Taiwan to test for HEV RNA by reverse transcription (RT)-PCR and for IgG and IgM anti-HEV by enzyme-linked immunosorbent assays. The sensitivities of IgG and IgM anti-HEV (relative to RT-PCR) were 86.7 and 53.3%, respectively. The specificities of IgG and IgM anti-HEV assays for diagnosing AHE were 92.1 and 98.6%, respectively. The rate of seroprevalence of IgG anti-HEV was 11% among healthy subjects in this nonendemic area, and it increased with age. In summary, IgG anti-HEV is a good diagnostic test for screening for AHE in nonendemic areas. The high rate of prevalence of anti-HEV in healthy subjects indicates that subclinical infection may exist.

Involvement of oxidative stress, NF-IL-6, and RANTES expression in dengue-2-virus-infected human liver cells

The liver has been suspected to be one of the major targets of dengue virus infection. Here, we detected increasing secretion of the chemokine RANTES (regulated upon activation, normal T cell expressed and secreted), which functions to recruit the immune cells, in dengue-virus-infected liver cells and patients. Three luciferase reporter genes with various deletions at the 5'-end of the RANTES promoter were constructed to explore the RANTES activation mechanism in human liver cells. The reporter gene was optimally activated by dengue-2 virus when the RANTES promoter contains the region from the transcription starting site (+1) to the nucleotide at the -181 position. NF-IL-6 and an undefined factor forming DNA-protein complexes in the RANTES promoter E and A/B regions in the infected cells were demonstrated by electrophoretic mobility shift assay. Further analysis showed that oxidative stress was an upstream inducer of NF-IL-6 and RANTES signaling in dengue-virus-infected liver cells. This finding was demonstrated by three antioxidants (N-acetyl-l-cysteine, nitro-l-arginine methyl ester, and pyrrolidine dithiocarbamate) used to suppress the activation. In contrast, the DNA binding activity of the undefined factor was not affected by the antioxidant treatment, indicating the existence of an oxidant-independent pathway. We hypothesize that dengue virus infection of the liver cells may trigger both an oxidant-dependent and an oxidant-independent pathway to up-regulate RANTES mRNA expression through activating NF-IL-6 and an undefined factor, respectively. In conclusion, the present study suggests a new direction for the study of liver pathogenesis involving RANTES in host immune responses during dengue virus infection.

Allergic eosinophilic gastroenteritis in a boy with congenital duodenal obstruction

Eosinophilic gastroenteritis (EG) is a rare allergy-related disease, especially in early childhood. We present the case of a 1 year 4 month old boy with congenital duodenal obstruction who developed EG. That diagnosis of EG was made by a series of imaging studies and was confirmed by upper gastrointestinal (UGI) endoscopic biopsy studies which showed significant tissue eosinophilia in both mucosal and submucosal layers. No evidence of parasite segment or ova was found in the stool and biopsy specimen. Specific IgE antibodies to milk were estimated to be 2 + (CAP system). Cow's milk allergy was highly suspected but not confirmed by consecutive elimination and challenge tests since the child was too much suffered to be tested. There was partial response to the 2-week treatment with Alfare (semi-elemental formula) and oral prednisolone 1 mg/kg/day. One month after initial examination, perforation of the stomach occurred and exploratory laparotomy disclosed stenosis of the duodenum. Congenital duodenal obstruction was diagnosed based on operative findings and previous sonographic findings. There has been only one report of EG in an infant with congenital duodenal obstruction. The nature of the relationships among cow's milk allergy as a possible etiologic factor, congenital duodenal obstruction as an predisposing factor and EG involvement at both mucosal and submucosal layers remains unclear.

Resolution of refractory hepatic hydrothorax after chemical pleurodesis with minocycline

Management of refractory hepatic hydrothorax is a challenge to physicians in clinical practice. We reported two patients with hepatic hydrothorax, non-alcoholic cirrhosis and rapidly recurring pleural effusion. They failed to improve with diuretics and repeated thoracentesis. Refractory hepatic hydrothorax was successfully treated by minocycline-induced pleural symphysis. After pleurodesis, ventilatory function returned to normal in both patients. No recurrence of pleural effusion was noted. We suggest that minocycline pleurodesis is an alternative treatment for refractory hepatic hydrothorax because it is simple, safe and effective.

Endoscopic treatment of bleeding gastric varices by N-butyl-2-cyanoacrylate (Histoacryl) injection: long-term efficacy and safety

BACKGROUND

The long-term efficacy and safety of the endoscopic injection of N-butyl-2-cyanoacrylate (Histoacryl) were evaluated to define its role as the initial treatment for bleeding gastric varices.

METHODS

Ninety patients with bleeding gastric varices underwent endoscopic injections of Histoacryl for hemostasis within a 6-year period. Histoacryl was injected intravariceally as a 1:1 mixture with Lipiodol. Among the 90 patients, 5 had active bleeding and 85 had recent bleeding. Most of the varices were large (F2 or F3, 85 cases). The most common locations were the fundus and the posterior wall of the proximal body (94.4%). After Histoacryl injection, patients were followed endoscopically with retreatment as necessary.

RESULTS

The rate of hemostasis at 1 week was 94.4%. Recurrent bleeding occurred in 23.3% of the patients from 3 days to 16 months after the initial injection. Recurrent bleeding was stopped with reinjections of Histoacryl in 16.7% of the patients. The rate of definitive hemostasis was 93.3% (84 of 90). The treatment failure-related mortality rate was 2.2% (2 of 90). To date, 35 patients have died, mostly as a result of malignancy or liver failure, and 55 are still alive. The determining factor for long-term survival was the underlying disease leading to portal hypertension. There were few long-term complications except for Histoacryl cast extrusion-related mucosal defects.

CONCLUSIONS

Endoscopic injection of Histoacryl is highly effective for the treatment of bleeding gastric varices, with rare complications both acutely and long term. This treatment modality is appropriate as the first choice for bleeding gastric varices.

Positive and negative hematopoietic cytokines produced by bone marrow endothelial cells

Recently, cytokines and interleukins such as SCF, GM-CSF, G-CSF, TGF-beta, IL-6, IL-7, IL-8, IL-11 have been reported to be elaborated by endothelial cells. For further study, serum free bone marrow endothelial cell conditioned medium (BMEC-CM) was collected and ultrafiltrated by using a centriprep 10. The concentrated retentate (R-BMEC-CM) contained some substances whose molecular weight was more than 10 000 daltons. The filtrate (F-BMEC-CM) contained some substances whose molecular weight was less than 10 000 daltons. The effects of R-BMEC-CM and F-BMEC-CM on the growth of haematopoietic progenitors and the expression of cytokine and interleukin mRNAs of BMEC were investigated. The results showed that R-BMEC-CM stimulated the growth of CFU-GM, HPP-CFC, BFU-E, CFU-E, and CFU-Meg; while F-BMEC-CM inhibited the growth of these progenitors. Using the method of hybridizing to the Atlas cDNA Array, we were able to detect the presence of mRNAs of cytokines and interleukins in bone marrow endothelial cells. Our finding of the existence of mRNAs of SCF, GM-CSF, IL-6, TGF-beta, IL-1, and IL-11 in these cells was in agreement with the data reported previously. Furthermore, we detected mRNAs of MIP-2, Thymosion-beta4, PDGF, MSP-1, IFN-gamma, IL-13 and inhibin, which are related to haematopoiesis. Among these cytokines and interleukins, SCF, GM-CSF, IL-6, IL-1, and IL-11 are haematopoietic stimulators which may be responsible for the stimulative effects on the growth of haematopoietic progenitors. One of our new findings, the thymosin-beta4, is a small molecular haematopoietic inhibitor. It may be responsible for the inhibitory effect of F-BMEC-CM on haematopoietic progenitors. The presence of mRNAs of BMP, MSP-1, MIP-2, PDGF and IL-13 suggests that bone marrow endothelial cells might elaborate these substances. Their influence on haematopoietic progenitors needs further study.

[High-level expression of human vascular endothelial growth factor in Pichia pastoris]

The gene of VEGF165 was subcloned into the P. pastoris secretive expression vector pHIL-S1 and the recombinant expression plasmid pHIL-S1-VEGF165 was constructed. After transformation into yeast GS115, the positive transformants were obtained through phenotype selection and DNA Dot blotting. After induction by methanol, soluble dimer VEGF165 were expressed and secreted into the culture supernatant with its expression occupying 47% of the total protein in the supernatant. Dot blot analysis showed that the expressed human VEGF165 could bind to its receptors flt-1 and KDR.

DNA-Based immunization produces Th1 immune responses to hepatitis delta virus in a mouse model

Hepatitis delta virus (HDV) superinfection is one of the major causes of fulminant hepatitis in endemic areas of hepatitis B virus (HBV) infection. Currently, there is no effective treatment or vaccine against HDV superinfection. DNA-based immunization is a promising antiviral strategy to prevent or treat persistent viral infections. In this study, we investigated the immunological effects of DNA vaccines against HDV in BALB/c mice. Plasmid (pD) encoding large hepatitis D antigen (L-HDAg), or plasmid (pS/pD) coexpressing hepatitis B surface antigen (HBsAg) and L-HDAg, were injected into mice intramuscularly. The seroconversion rate, anti-HBs levels, anti-HDV titers, T-cell proliferation responses, and T-helper (Th)-release cytokine profiles were analyzed. Mice immunized with plasmids, pS/pD or pD, produced low, but significant, titers of anti-HDV antibodies. In contrast, pS/pD induced much stronger anti-HBs titers in the immunized animals. Interestingly, splenic lymphocytes derived from pS/pD-inoculated mice demonstrated significant proliferation responses to recombinant HBsAg and HDAg, and resulted in a Th1-like immune response as suggested by the production of interferon gamma (INF-gamma) and interleukin-2 (IL-2), but not IL-4. The splenic lymphocyte derived from the pD-inoculated mice showed a similar Th1 response to the stimulation of HDAg, but not to HBsAg. In conclusion, our results suggest that DNA vaccines against HDV can induce significant cellular immune responses with a Th1 preference. HBV and HDV coimmunization can be performed by DNA vaccines. These results are promising for the future development of prophylactic and therapeutic HDV vaccines.

Dengue virus infects human endothelial cells and induces IL-6 and IL-8 production

In this study dengue virus (DV) was found to infect primary endothelial cells derived from human umbilical cord veins (HUVEC) and alter their cytokine production. Dengue virus infection of HUVEC was confirmed by an increase in plaque-forming units in the culture supernatant and by immunofluorescence assay. HUVEC produced large amounts of interleukin (IL)-6 and IL-8 but not IL-1beta after DV infection. Both the replication of DV and the production of IL-6 and IL-8 by HUVEC after DV infection were inhibited by ribavirin, an antiviral synthetic guanosine analogue. Additionally, increased serum levels of IL-6 and IL-8 were observed in patients with dengue hemorrhagic fever but not dengue fever. Therefore, our results suggest that endothelial cells can be a target for DV infection, and that DV-induced IL-6 and IL-8 production by endothelial cells may contribute to the pathogenesis of dengue hemorrhagic fever.

Follow-up of invasive pituitary macroadenoma in 56 patients within a duration of 5 years

From June 1986 to September 1996, 56(30%) patients with invasive pituitary macroadenoma were studied retrospectively. We compared the clinical and endocrinological characteristics, neuroimaging findings, and surgical outcome of these patients in a period of follow up of 5 years. Twenty-one patients (38%) were found to have a prolactinoma, 8 patients (14%) had a GH-producing adenoma, and 27 patients (48%) had non-functional tumors. Pituitary apoplexy was found in 16 cases (29%). Their age ranged from 15 to 72 years and no sex difference (F:M = 27:29) was found. According to Hardy's classification, all the 56 tumors were invasive pituitary macroadenoma, of a tumor size more than 10 mm with sellar floor erosion partially or diffusely or paracarvenous sinus invasion. Those tumors were divided into grade III (tumor causing localized perforation of the sellar floor), and IV (tumor destroying entire sellar floor diffusely); the tumors were further subdivided into stage C (3rd ventricle grossly displaced), D (intracranial intradural extension) and E (tumors invading the cavernous sinus through the lateral dural envelope of the sellar). Eight out of 56 tumors belonged to grade III stage C, 18 tumors were grade III stage D, 8 tumors were grade IV stage D, and the other 22 were grade IV stage E. Fifty-one patients received transsphenoidal craniectomy for tumor removal, one patient took subfrontal craniotomy only and 4 cases received both. Most patients improved significantly in visual field and general quality of life after surgery. In this study, it was concluded that: 1) surgical intervention as quick as possible was proven advantageous, especially in patients with an invasive macroadenoma; 2) in cases with invasive pituitary macroadenomas, the patients, with grade III and IV tumors, had a longer symptom-free interval than those who refused surgical intervention and radiotherapy with the same grade tumor; 3) to achieve satisfactory late results, multidisciplinary treatment was necessary: post-operative radiotherapy ranging from 4500 to 6500 rads was done in 50 patients, endocrine therapy in 52 patients and adjunct bromocriptine treatment was done in 13 patients with prolactinomas; 4) symptomatic recurrence or elevated postoperative hormone levels occurred in 20(35%) cases. There was a high incidence of recurrence in 6(6/20) GH-secreting tumors, and in 8(8/20) prolactinomas with preoperative prolactin levels more than 200 eta g/dl.

Prospective case-controlled trial of adjuvant chemotherapy after resection of hepatocellular carcinoma

Recurrence of hepatocellular carcinoma (HCC) after curative hepatic resection is frequent and is an important factor adversely influencing long-term survival. The role of postoperative chemotherapy in the reduction of tumor recurrence rate is still controversial. During the period of 1992-1995 a series of 49 patients who underwent curative resection of HCC and had at least one risk factor of tumor recurrence were followed in this prospective study. Patients were allocated to adjuvant chemotherapy and control groups. Twenty-four patients received a combination of low dose intravenous epirubicin (20 mg/m2) and mitomycin (5 mg) monthly for seven courses starting 5 to 6 weeks after surgery. Twenty-five patients had no adjuvant treatment. The disease-free and overall survivals were compared for the two groups. A total of 154 courses of chemotherapy were given to the 24 patients. The chemotherapy-related side effects were mild and tolerable with no mortality. At a median follow-up of 39 months (range 9-71 months), 9 patients in the adjuvant chemotherapy group and 16 patients in the control group developed tumor recurrence. The respective 1-, 2-, 3-, and 5-year disease-free survival rates were 75%, 67%, 63%, and 63% for patients in the adjuvant chemotherapy group and 68%, 42%, 37%, and 32% for patients in the control group (p = 0.0575). The 1-, 2-, 3-, and 5-year overall survival rates were 100%, 96%, 77%, and 72% in the adjuvant chemotherapy group and 92%, 67%, 63%, and 51% in the control group (p = 0.0746). In conclusion, postoperative adjuvant chemotherapy using the present regimen has a tendency to reduce tumor recurrence rate and may improve long-term survival for high risk patients.

1.5-mum emissions from laser-diode-pumped Nd-doped microchip solid-state lasers

1.5-mum emissions from Nd:YAG, Nd:YVO(4), and LiNdP(4) O>(12) microchip lasers pumped by laser diodes have been observed. These coherent emissions are attributed to the effect of high-energy modified lattice vibration owing to the existence of Nd ions as well as to stimulated intracavity Raman scattering enhanced by the microchip configuration. A four-wave mixing process involving two lasing fields and a Stokes field was identified as the generator of new adjacent 1.5-mu;m emission.

[Effects of serum-free murine bone marrow endothelial cell conditioned medium on the growth of CFU-E and BFU-E]

Serum-free murine bone marrow endothelial cell conditioned medium(mBMEC-cm) was collected. The mBMEC-cm was ultrafiltered in Centriprep. The concentrated retentive substance of mBMEC-cm (MW > 10,000) and filtrate of mBMEC-cm(MW < 10,000) were obtained. The effects of mBMEC-cm on the growth of CFU-E and BFU-E were investigated. The results showed: 1. The retentive substance of mBMEC-cm significantly enhanced the growth of CFU-E and BFU-E. The effects of mBMEC-cm(2%-6%, V/V) on the growth of CFU-E and BFU-E were dose-dependent. 2. The filtrate of mBMEC-cm markedly inhibited the growth of CFU-E and BFU-E. The effects of the filtrate of mBMEC-cm on the growth of CFU-E and BFU-E were also dose-dependent. The mechanism of regulation will be studied further.

Prevalence and risk factor analysis of TTV infection in prostitutes

TTV, a DNA virus, has been isolated from patients with non-A to non-E post-transfusion hepatitis. In the past it was assumed that TTV was transmitted parenterally. It is unclear whether sexual contact leads to transmission of this virus. In this study, two sets of TTV-specific polymerase chain reaction primers were used to detect serum TTV DNA in 140 prostitutes and 136 controls. The prevalence of TTV DNA in prostitutes was significantly higher than in the control group (46/140 [32.9%] vs. 29/136 [21.3%]; P = 0.043). There was no significant difference in the prevalence of positive antibody to hepatitis A virus (anti-HAV) in either group (87.8% for prostitutes, 85.3% for controls). No particular risk factor was significantly associated with positive TTV DNA in prostitutes. In summary, TTV is highly prevalent in prostitutes. Transmission of TTV via sexual contact is not as efficient as transmission of hepatitis C and D viruses and GB virus-C hepatitis G virus. The high prevalence of TTV in controls indicates that there are diverse routes of transmission of this virus.

Fractal analysis of nuclear medicine images for the diagnosis of pulmonary emphysema: interpretations, implications, and limitations

OBJECTIVE

The purpose of this study was to investigate, on images obtained in nuclear medicine examinations, the physical meanings and consequent implications of fractal analysis developed in a recent study that was reported to be effective in quantifying the heterogeneous distribution of carbon particle radioaerosol in the lungs.

MATERIALS AND METHODS

Fractal dimensions were computed for 108 sets of radionuclide imaging data from 28 patients according to the methods in a previous report, and were then correlated with the ratio of tissue areas segmented at two thresholds (15% and 35% of maximal radioactivity).

RESULTS

Fractal dimension was found to linearly correlate with the ratio natural logarithm of tissue areas segmented at two different threshold levels (n = 108, r = 0.999), with regression slope accurately predicted (error = 0.06%). Bland-Altman analysis showed that fractal dimensions ranging from 0.2 to 1.9 can be explained by this area ratio with disagreement of only 5.13% at two standard deviations; thus, fractal dimension seems to be an over-simplified parameter unrelated to spatial heterogeneity of radioaerosol distribution.

CONCLUSION

The analysis of this study suggested that the fractal dimension defined in a previous report was limited to the indication of the percentage area of low-radioactivity regions with respect to total tissue area in the image. Because the fractal dimension partially reflects, but is not specific to, a certain degree of focal spots of low radioactivity, we suggest using fractal analysis in clinical practice only with careful control and thorough understanding of the physical meanings.

Prevalence and risk factor analysis of TTV infection in prostitutes

TTV, a DNA virus, has been isolated from patients with non-A to non-E post-transfusion hepatitis. In the past it was assumed that TTV was transmitted parenterally. It is unclear whether sexual contact leads to transmission of this virus. In this study, two sets of TTV-specific polymerase chain reaction primers were used to detect serum TTV DNA in 140 prostitutes and 136 controls. The prevalence of TTV DNA in prostitutes was significantly higher than in the control group (46/140 [32.9%] vs. 29/136 [21.3%]; P = 0.043). There was no significant difference in the prevalence of positive antibody to hepatitis A virus (anti-HAV) in either group (87.8% for prostitutes, 85.3% for controls). No particular risk factor was significantly associated with positive TTV DNA in prostitutes. In summary, TTV is highly prevalent in prostitutes. Transmission of TTV via sexual contact is not as efficient as transmission of hepatitis C and D viruses and GB virus-C hepatitis G virus. The high prevalence of TTV in controls indicates that there are diverse routes of transmission of this virus.

Cyclic AMP regulates mRNA expression of alpha-1d and alpha-2a adrenergic receptors in cultured human corpus cavernosum smooth muscle cells

While the physiological effects of contractile (e.g. norepinephrine) and relaxatory (e.g. PGE1, forskolin) agents on corpus cavernosum smooth muscle tone have been characterized, the regulation of alpha adrenergic receptor mRNA expression in erectile tissue remains to be investigated. The goal of this study was to investigate the modulation of alpha-1 and alpha-2 adrenergic receptor mRNA expression in cultured human corpus cavernosum smooth muscle cells in response to increased intracellular cAMP induced by prostaglandin E1 and forskolin. Human corpus cavernosum smooth muscle cells were incubated for 24 h with or without PGE1 (5.7 microM), forskolin (10 microM) or an admixture of both. Total RNA was prepared from the cultures. Expression of alpha-1d adrenergic receptor, alpha-2a adrenergic receptor and m2 muscarinic acetylcholine receptor was determined by RNase protection assays. Loading was normalized by RNase protection of the housekeeping gene, cyclophilin A. The relative abundance of mRNAs was quantitated by scanning densitometry. Treatment of human corpus cavernosum smooth muscle cells with PGE1 or forskolin resulted in decreased mRNA expression of alpha-1d and alpha-2a adrenergic receptors and m2 muscarinic acetylcholine receptor when compared to untreated cells. Combinations of PGE1 and forskolin produced a more pronounced decrease in mRNA than either agent alone. PGE1 and forskolin increased intracellular levels of cAMP in human corpus cavernosum smooth muscle cells and combinations of both agents produced a more pronounced increase in cAMP synthesis. These results suggest that cAMP modulates the expression of alpha adrenergic receptors, one of the principal contractile receptor systems in the corpora cavernosa. These observations further support the concept that erectile function is a balance between contractile and relaxatory processes, which in turn regulate structure and function of the corpora cavernosa.

[Study on the optimum experimental conditions for the steady growth of human K-562 cell line]

The results of the assays of growth state, semisolid colony culture, cytomorphological and chromosome analysis for K-562 cell line showed that the cells had the similar biological characteristics with the cells which were originally established. It suggests that the growth state of K-562 cells under the experimental conditions in our laboratory are steady.

Clinical and epidemiological implications of swine hepatitis E virus infection

In nonendemic areas, most patients with acute hepatitis E were infected through traveling to endemic areas. However, some patients did not have a history of foreign travel before infection. Furthermore, high seroprevalence rates of antibody to hepatitis E virus (anti-HEV) were found in the general adult population in some countries without any recorded outbreak of hepatitis E. The significance of anti-HEV assay in these subjects remains obscure. To study if swine might be a source of HEV infection, HEV was tested in sera of 235 pigs in Taiwan, and from 5 patients with acute HEV infection who either denied or did not provide any foreign travel history. Three (1.3%) pigs had detectable swine HEV RNA. The swine and human HEV strains from Taiwan formed a monophyletic group, distinct from three previously reported groups: the United States human and swine HEV strains, the Mexico strain, and the largest group composed of the Asian and the African strains. The identity of nucleotide sequences was 84-95% between swine and human HEV strains in Taiwan, and 72-79% between Taiwan strains and those from different areas. The predicted amino acid sequence of a Taiwan swine HEV strain within the peptide 3-2 used in commercial anti-HEV assay showed a high identity (91-94%) with those of other human and swine HEV strains. Swine may be a reservoir of HEV and subclinical swine HEV infection may occur. Cross-reactivity of current anti-HEV assay may account for the high prevalence rate of anti-HEV in the general population in nonendemic areas.

[The effects of cytokines produced by bone marrow endothelial cells on the regulation of hematopoiesis]

In this study, the effects of bone marrow endothelial cell conditioned medium (BMEC-CM) on hematopoietic progenitors and the expression of cytokines mRNA of BMEC were investigated. BMEC-CM was ultrafiltrated in Centriprep-10, an ultrafiltering concentrator. The retentate (MW>10 kD) and filtrate (MW<10 kD) were obtained. The effects of different components of BMEC-CM on the murine hematopoietic progenitors were examined. The results showed that the retentate of BMEC-CM (MW>10 kD) significantly promoted the growth of CFU-GM, CFU-E, BFU-E, CFU-Meg and HPP-CFC, while the growth of CFU-GM, CFU-E, BFU-E, CFU-Meg and HPP-CFC were markedly inhibited by the filtrate of BMEC-CM (MW<10 kD). The effects of BMEC-CM were dose-dependent. The presence of mRNAs for GM-CSF, TGF-beta, bone morphogenetic protein 2A, basic fibroblast growth factor receptor, endothelin-2, macrophage-stimulating 1 (MSP-1), thymosin-beta10, connective tissue growth factor, macrophage inflammatory protein 2 alpha (MIP-2alpha), IL-6, IL-11, IL-13 and IFN-gamma mRNA were successfully detected by Atlas Arrays.

Detection and viral nucleotide sequence analysis of transfusion-transmitted virus infection in acute fulminant and non-fulminant hepatitis

The impact of transfusion-transmitted virus (TTV) infection on acute fulminant and non-fulminant hepatitis is unclear. In this study, serum samples from 164 patients with acute hepatitis of various aetiologies, from 34 asymptomatic hepatitis B virus carriers and from 202 healthy adults were tested for TTV DNA by the semiconserved nested polymerase chain reaction. TTV viraemia was prevalent in patients with acute hepatitis C, in patients with acute hepatitis D virus superinfection and in patients with non-A-E hepatitis (27-30%) but the incidence was not significantly different from that of healthy controls (31 of 202, 15.3%). There were no significant differences in gender, age, presence of hepatitis G virus, the occurrence of fulminant hepatitis, or in serum albumin, bilirubin or alanine aminotransferase levels (9/30 vs 35/134) between patients with or without TTV viraemia. Seven of the nine TTV-positive patients with fulminant hepatitis were co-infected with hepatitis C, D or E. TTV clones from 18 subjects, with or without fulminant hepatitis, were sequenced and analysed phylogenetically. Eleven (61. 1%) belonged to TTV group 1, six (33.3%) to TTV group 2 and one to TTV group 3. No particular strain of TTV was associated with fulminant hepatitis. In summary, in Taiwan, TTV is prevalent in the general population as well as in patients with liver diseases. TTV plays an insignificant role in acute fulminant and non-fulminant hepatitis. Its influence on outcome requires a longitudinal study.

Changes in invertase activities and reducing sugar content in sweetpotato stored at different temperatures

Cured sweetpotato roots were stored at different temperatures (4.5, 15.6, and 24 degrees C) for 7 weeks and assayed for invertase activities and reducing sugar levels during two separate years. Invertase activities and reducing sugar concentration significantly increased in the roots kept at low temperature. Of the three types of invertases assayed, acid invertase specific activity was the highest. Acid invertase was the most influential in determining reducing sugar levels in stored sweetpotato. Cultivar differences were found in invertase specific activities and reducing sugar concentration. Reducing sugar content was highly correlated to acid and total invertase activity, regardless of cultivar.