The genotypes of hepatitis C virus in patients with chronic hepatitis C virus infection in southern Taiwan

To investigate the genotype distribution of hepatitis C virus (HCV) in southern Taiwan, the sera from 56 patients with chronic HCV infection were studied. Twenty-nine patients were men and 27 were women. Age ranged from 22 to 65 years (mean, 47.3 +/- 11.4). Eighteen of them had chronic persistent hepatitis, 27 had chronic active hepatitis, and 11 had liver cirrhosis. HCV RNA was detected by reverse transcription-nested polymerase chain reaction using primers derived from the 5'-noncoding region. The genotypes of HCV were determined by amplification of the core region with the type-specific primers as described by Okamoto et al.. All sera were positive for HCV RNA. The prevalence rates of genotypes were as follows: 1b/II, 44.6%(25/56); 2a/III, 41.1%(23/56); 2b/IV, 3.6%(2/56); mixed 1b/I + 2a/III, 5.4%(3/56): mixed 1b/II + 2b/IV, 1.8%(1/56) and type unclassified 3.6%(2/56). The distribution of genotypes was not related to the patients' age, sex, and histological changes. Nevertheless, patients having past history of blood transfusion had a significantly higher rate of HCV type 2a/III infection (72.2% versus 34.2%, p < .05, chi-square test). We concluded that both of the HCV genotypes 1 b/II and 2a/III are predominant types in southern Taiwan and regional HCV genotype distribution may differ even within this island. Selective transmission of specific genotypes may pass along different infectious routes.

Nonporous silicone polymer coating of expanded polytetrafluoroethylene grafts reduces graft neointimal hyperplasia in dog and baboon models

PURPOSE

Neointimal hyperplasia frequently develops after placement of prosthetic vascular grafts and is a major cause of graft failure. This study was an attempt to prevent vascular lesion formation by coating the graft luminal surface with a thin layer of nonporous silicone polymer, and subsequently with an ultrathin layer of vapor phase (plasma gas)-deposited fluoropolymer, thereby providing a smooth and chemically uniform surface that was postulated to limit pannus tissue ingrowth across the graft anastomoses.

METHODS

Bilateral femoral arteriovenous (AV) conduits were constructed in four dogs using expanded polytetrafluoroethylene graft materials (ePTFE; 6-mm inside diameter, 2.5-cm long). In each animal, one femoral AV shunt was constructed from a graft whose luminal surface was entirely coated with polymer. On the contralateral side, an uncoated graft served as a control. Bilateral aortoiliac grafts were placed in three baboons using 5-cm segments of ePTFE (4-mm inside diameter). One end (1 cm) of each graft had been coated with polymer. In each animal, the coated end of one graft was placed proximally and the coated end of the second graft was placed distally in the contralateral vessels.

RESULTS

All grafts were patent at 30 days. In the dog model, there was a significant reduction in graft neointimal area at the venous anastomoses for the coated grafts compared with the uncoated grafts (0.03 +/- 0.02 mm2 and 1.11 +/- 0.54 mm2, respectively; p < 0.05). In the baboon model, the silicone coating significantly reduced the graft neointimal thickness (0.003 +/- 0.003 mm vs 0.21 +/- 0.05 mm; p < 0.05) and neointimal area (0.05 +/- 0.08 mm2 vs 0.82 +/- 0.58 mm2; p < 0.05).

CONCLUSIONS

These data demonstrate that healing of ePTFE grafts can be effectively modified by altering the physical properties of the graft surface. Neointimal hyperplasia within ePTFE grafts is significantly reduced by the local application of a fluorocarbon-coated, silicone-based polymer. The resulting graft flow surface effectively prevents tissue ingrowth from the adjacent native vessel, thereby preserving the anastomosis luminal area. This approach could represent a new strategy for limiting graft surface anastomotic neointimal hyperplasia.

The beneficial effect of taurine on the prevention of human endothelial cell death

This study was designed to test the hypothesis that the antioxidant taurine may modulate human endothelial cell (EC) death (apoptosis versus necrosis). Sodium arsenite (80 microM) alone and in combination with tumor necrosis factor-alpha (25 ng/mL) caused EC apoptosis after 24 h of treatment. Taurine (.5 mg/mL) added at 0 and 6 h could significantly attenuate EC apoptosis, and oxidative state in response to lipopolysaccharide and tumor necrosis factor-alpha stimulation. EC necrosis was induced by activated neutrophils (PMNs). Taurine reduced PMN-mediated EC necrosis in a dose-dependent manner. Moreover, treatment of ECs with a calcium ionophore, A23187 (1.0-4.0 microM), resulted in both EC apoptosis and necrosis. Taurine significantly abrogated A23187-mediated intracellular calcium elevation and EC death. These data indicate that taurine, possibly through its antioxidant activity and regulation of intracellular calcium flux, can prevent EC dysfunction and cell death, which may have implications for the application of this amino acid in the amelioration of acute lung injury during systemic inflammatory response syndrome.

Mechanisms involved in sodium arsenite-induced apoptosis of human neutrophils

Apoptosis is a distinct mechanism by which eukaryotic cells die. Factors governing the induction of polymorphonuclear leukocyte (PMN) apoptosis should be important in understanding resolution of acute inflammation. The mechanisms for induction of PMN apoptosis remain uncertain; however, oxidative stress has been suggested. The aims of this study were to determine whether reactive oxygen intermediates play a role in PMN apoptosis and to investigate inhibition of this process by selective use of antioxidants. PMN were isolated from 10 healthy volunteers. PMN (1 x 10(6) PMN/mL) were cultured in 40, 80, and 160 microM of arsenite for 2, 6, 12, 18, and 24 h. Apoptosis was assessed qualitatively by morphology and gel electrophoresis and quantitatively by CD16 receptor expression and propidium iodide DNA staining. There was a significant (P < 0.05) increase in the rate of apoptosis on incubation with arsenite (80 and 160 microM). To investigate the mechanism of this process, intracellular respiratory burst activity was measured following arsenite culture. We found that arsenite-induced PMN apoptosis correlated with an increase in intracellular respiratory burst. To further investigate the role of oxidative injury in inducing apoptosis, the antioxidants catalase, dimethyl sulfoxide (DMSO), glutathione (GSH), N-acetylcysteine (NAC), and taurine were investigated and we demonstrated that GSH, NAC, and taurine were significantly protective against arsenite-induced apoptosis. However, catalase and DMSO failed to induce protection. This study demonstrates that arsenite induces PMN apoptosis through an oxygen-dependent mechanism that can be prevented through selective antioxidants.

Mycotic aneurysm due to non-typhi salmonella: report of 16 cases

From 1990 through 1994, we collected information on all cases of mycotic aneurysms due to non-typhi Salmonella that occurred at the Veterans General Hospital in Kaohsiung, Taiwan. All cases of salmonella bacteremia were reviewed to find any additional cases. A total of 16 cases of salmonella mycotic aneurysms occurred. The mortality rate was 100% among the three patients treated with medical therapy alone. Nine (70%) of the 13 patients who received surgical and medical therapy survived. Ten of the 16 cases were due to Salmonella choleraesuis. Diagnosis was established by computed tomography or aortography. Gallium scans were of no diagnostic utility. A culture of blood from a patient with underlying atherosclerosis that is positive for invasive Salmonella should prompt a search for a mycotic aneurysm. Treatment with a third-generation cephalosporin and resection of the infected vessel is usually successful.

Inhibition of murine leukemia virus with poly-2'-O-(2,4-dinitrophenyl)poly[A]

Poly-2'-O-(2,4-dinitrophenyl)poly[A] (DNP-poly[A] is a potent inhibitor of reverse transcriptases from a variety of sources (I. Kang and J. H. Wang, J. Biol. Chem. 269:12024-12031, 1994). In the present study, its inhibitory effect on the reverse transcriptase (RT) from Moloney murine leukemia virus (MuLV) was investigated. DNP-poly[A] was found to enter the virus spontaneously and to completely inhibit the RT within 30 min at 0 degree C. The inhibitor was also spontaneously transported into isolated human lymphocytes and leukocytes at 37 degrees C. Animal studies have demonstrated the effectiveness of DNP-poly[A] as an antiviral drug when administered intraperitoneally at various doses from 1 to 100 mg/kg of body weight. MuLV-infected mice show the presence of RT in their blood as well as increased numbers of leukocytes. After the administration of DNP-poly[A] at a dosage of 100 mg/kg of body weight three times a week over a 3-week period, RT could no longer be detected by an ultrasensitive RT-PCR assay. Autopsy showed that the spleens of infected but untreated mice were enlarged 2- to 10-fold, with fused nodules and the proliferation of large abnormal lymphocytes, whereas the spleens of infected but treated mice resembled the normal spleens of uninfected control mice. These observations indicate that further study of DNP-poly[A] as a general antiretroviral agent is desirable.

Treatment of chronic hepatitis C with interferon-alpha: a preliminary report

Interferon alpha (IFN-alpha) has been indicated to be dramatically effective in some but not all patients with chronic hepatitis C virus (HCV) infection. We investigated prospectively 27 patients of chronic hepatitis C, 12 females and 15 males, treated with IFN-alpha for a better regimen of the therapy and for any effective predictor of response to the treatment. All patients were treated with 3 to 6 million units (MU) of recombinant IFN-alpha 2b (n = 15) or lymphoblastoid IFN-alpha (n = 12) given 3 times weekly for 12 to 36 weeks. Patients with normal alanine aminotransferase (ALT) value during therapy, who sustained this response throughout 6 months follow-up after treatment was completed, were grouped into the complete responders. Patients with normal ALT value during therapy but who relapsed after treatment completed, were grouped as partial responders. Non-responders were defined as patients without normal ALT value during therapy. The rates of complete response, partial response, and non-response were 29.6%, 40.8%, and 29.6%, respectively. The degree of response to IFN-alpha therapy was not related to age, sex, type of IFN-alpha, history of blood transfusion, the state of liver pathology, or pretreatment level of ALT value. The complete responsive rate to IFN-alpha was higher in patients treated with total dose above 215 MU [38.1% (8/21) vs. 0% (0/6), p = 0.06], in patients treated for at least 24 weeks [40% (8/20) vs. 0% (0/7), p < 0.05], and in patients with non-genotype 1b/II HCV infection [40% (8/20) vs. 0% (0/7), p < 0.05]. We concluded that IFN-alpha was effective in the treatment of chronic HCV infection, particularly in those other than HCV genotype 1b/II. A high-dose, and long-duration regimen may be recommended for better response of chronic hepatitis C to IFN-alpha therapy.

Molecular cloning and deduced primary structures of acidic and basic phospholipases A2 from the venom of Deinagkistrodon acutus

This paper presents the nucleotide sequences of the cDNAs encoding three acidic phospholipases A2 and one basic phospholipase A2 from Deinagkistrodon acutus venom. The deduced primary structure of the basic enzyme is closest to that of the basic neurotoxic enzyme from Trimeresurus mucrosquamatus venom, while the acidic phospholipases from D. acutus have highest sequence similarity to that from Agkistrodon halys pallas. The phylogeny of this monotypic species is discussed.

[Effect of IGF-II on progesterone production by cultured rat luteal cells in vitro]

It has been reported recently that IGF-II plays an important role in the regulation of ovarian function. The aim of this study is to investigate whether IGF-II can affect progesterone production by cultured rat luteal cells. The results showed that IGF-II could significantly stimulate basal progesterone production in a dose-dependent manner without altering the cAMP content. IGF-II could enhance 3H-leu incorporation into protein and 3H-TdR incorporation into DNA of the luteal cells, but these effects could be inhibited by CYX and Act D. The above results suggest that stimulating effect of IGF-II on progesterone production by rat luteal cells may be related to enhanced protein and DNA synthesis.

Distinct cellular compartment of cyclin-dependent kinase 5 (Cdk5) and neuron-specific Cdk5 activator protein (p35nck5a) in the developing rat cerebellum

We have elucidated the spatial and temporal localization of Cdk5 and p35nck5a in the developing rat postnatal cerebellum. Both proteins were highly expressed in cell bodies of post mitotic and immature neurons. The localization of Cdk5 in cellular compartment was changed from cell body to the axon in development. On the other hand, p35nck5a was always expressed in the cell body throughout cerebellum development. The Cdk5 kinase activity was correlated with the expression of p35nck5a rather than that of Cdk5. These results indicate that p35nck5a is a physiological activator of Cdk5 in immature neurons and further suggest that Cdk5 has another function in mature neurons.

Purification of bovine thymus cytosolic C-terminal Src kinase (CSK) and demonstration of differential efficiencies of phosphorylation and inactivation of p56lyn and pp60c-src by CSK

The C-terminal src kinase (CSK) is a ubiquitously expressed, cytosolic enzyme capable of phosphorylating and inactivating several plasma membrane-bound src-family protein tyrosine kinases in vitro [Nada, S., Okada, M., MacAuley, A., Cooper, J.A., & Nakagawa, H. (1990) Nature 351, 69-72; Bergman, M., Mustelin, T., Oetken, C., Partanen, J., Flint, N.A., Amrein, K.E., Autero, M., Burn, P., & Alitalo, K. (1992) EMBO J. 11, 2919-2924]. We purified CSK to apparent homogeneity from bovine thymus cytosol to study in vitro how the purified enzyme recognizes the various src-family kinases as its substrates. A novel assay method was developed for assaying the ability of CSK to inactivate src-family tyrosine kinases. With this assay method, we demonstrated that CSK inactivated p56lyn with a significantly higher efficiency than pp60c-src. Phosphopeptide mapping of CSK-phosphorylated p56lyn and pp60c-src shows that the consensus tyrosine residue (also termed tail tyrosine) in the C-terminal regulatory domain of p56lyn was phosphorylated by CSK with an efficiency much higher than that of pp60c-src. Thus, the higher efficiency of inactivation of p56lyn by CSK is a result of the ability of p56lyn to serve as a better substrate of CSK. The synthetic peptides derived from the C-terminal portion of p56lyn and pp60c-src were much poorer substrates than the intact src-family kinases for CSK, indicating that the local structure around the tail tyrosine is not sufficient to direct efficient phosphorylation of p56lyn by CSK. Nevertheless, the slightly higher efficiency displayed by CSK in phosphorylating the peptide derived from the C-terminal portion of p56lyn than that from pp60c-src suggests that the structural differences between the C-terminal portions of p56lyn and pp60c-src contribute to the differential efficiencies displayed by CSK in phosphorylating the two kinases. Determination of the CSK-phosphorylation site in the src-C-terminal peptide by phosphopeptide mapping reveals that the whole C-terminal regulatory domain and an adjacent part of the protein kinase domain contain some of the structural determinants directing CSK to phosphorylate the consensus tail tyrosine of the src-family kinases.

Localization and developmental changes in the neuron-specific cyclin-dependent kinase 5 activator (p35nck5a) in the rat brain

Mammalian brains contain a cde2-like protein kinase which is a heterodimer of cyclin-dependent kinase 5 (Cdk5) and a brain-specific regulatory subunit with a molecular weight of 35,000. In this study, we examined the temporal and spatial expression patterns of p35nck5a in the developing rat brain. Northern blot analysis showed that p35nck5a messenger RNA expression was low in the brain of 12-day postcoitum rats, and increased to a much higher level from 18 days postcoitum to two weeks after birth, and then declined at three weeks after birth. These developmental changes in p35nck5a expression correlated with the changes in Cdk5-associated kinase activity during brain development. These data suggest that p35nck5a is the specific activator for Cdk5 in the brain. Immunohistochemical and in situ hybridization studies demonstrated the presence of p35nck5a protein in postmitotic neurons but not in glial cells at all stages of brain development, indicating that p35nck5a is a neuron-specific protein. In the adult brain, the protein was rich in cell bodies and dendrites, and only very low amounts were detected in axons. In fetal and neonatal brains, however, axonal pathways such as the corpus callosum and external capsule were also stained with anti-p35nck5a antibody. Our findings suggest that p35nck5a is neuron specific, and a specific activator for Cdk5, and the subcellular localization of the two is strictly regulated depending on brain development. Neuronal Cdc2-like kinase may play key roles in neuronal maturation, synaptic formation, and neuronal plasticity.

Postextubation laryngeal edema in adults. Risk factor evaluation and prevention by hydrocortisone

OBJECTIVE

To evaluate the risk factors for postextubation laryngeal stridor and its prevention by hydrocortisone in adult patients.

DESIGN

Prospective, randomized, double-blind, placebo controlled study.

SETTING

Medical and surgical ICU of a tertiary teaching hospital.

PATIENTS

77 consecutive patients of both sexes, who had undergone tracheal intubation for more than 24 h and fulfilled the weaning criteria, were eligible for the study. Patients were excluded if they were less than 15 years of age, had a disease or the surgery of the throat, or had been extubated during the current hospitalization.

INTERVENTION

The control group received placebo (normal saline 3 cc) and the experimental group received hydrocortisone 100 mg by intravenous infusion 60 min before extubation.

MAIN OUTCOME MEASURES

Patients were observed 24 h after extubation for symptoms or signs of laryngeal edema or stridor: prolonged inspiration with accessory usage of respiratory muscles or crowing sound with inspiration or reintubation.

RESULTS

The overall incidence of postextubation stridor was 22% (17/77). Only one patient (1%), who belonged to the control group, needed reintubation. 39% of female patients and 17% of male patients developed stridor. The relative risk of females developing this complication was 2.29. 7/39 of the hydrocortisone group and 10/38 of patients in the control group developed postextubation stridor.

CONCLUSIONS

Hydrocortisone did not significantly reduce the incidence of postextubation laryngeal edema or stridor. From the risk factors evaluated, we were unable to demonstrate a statistical correlation between postextubation stidor and the duration of the intubation, the patient's age, the internal diameter of the endotracheal tube, or the route of intubation. However, female patients were more likely to develop this complication.

Klebsiella pneumoniae-induced mycotic aneurysm of the abdominal aorta complicated by bloody pleural effusion--a case report

A 68-year-old diabetic male who suffered from recurrent severe lumbago and high fever was found to have mycotic abdominal aneurysm. His symptoms did not improve after maximum-dose antibiotic therapy. Bloody pleural effusion on the left side was noticed hours before he expired. Klebsiella pneumoniae alone was isolated from blood from cellulitis-related bacteremia, when aneurysm formation was complete and later from bloody pleural effusion. To our knowledge, this is the first report of mycotic abdominal aneurysm of solely Klebsiella pneumoniae complicated by bloody pleural effusion.

The balance between postsynaptic Ca(2+)-dependent protein kinase and phosphatase activities controlling synaptic strength

The activities of protein kinases and phosphatases are believed to regulate neuronal activity and synaptic plasticity in brain. Numerous in vivo and in vitro studies have shown that synaptic strength appears stable under basal conditions and during long-term potentiation (LTP) expression. This may reflect a balance between protein kinase and phosphatase activities. To provide experimental evidence for this hypothesis, and based on our knowledge that Ca2+/CaM activates protein kinases and phosphatases and that postsynaptic Ca2+/CaM signal pathways play important roles in synaptic plasticity, we examined the contribution of postsynaptic Ca(2+)-dependent protein kinases and calcineurin (CaN) in regulating synaptic strength. We show that inhibiting postsynaptic Ca2+/CaM-dependent protein kinase II (CaM-KII) and Ca2+/phospholipitidyserine-dependent protein kinase (PKC) in hippocampal CA1 neurons attenuates significantly the expression of LTP, but not basal synaptic transmission. On the other hand, the inhibition of postsynaptic CaN enhances synaptic transmission at potentiated and naive synapses, and increases significantly the magnitude of synaptic potentiation during the induction phase of LTP. These results indicate that postsynaptic CaM-KII and PKC activities are essential for maintaining LTP expression, but CaN activity limits synaptic strength at stable levels during both basal and potentiated synaptic transmission; that is, the dynamic balance between protein phosphorylation and dephosphorylation that sets physiological synaptic strength is dominated by CaN activity.

Study on the isentropic equations of nucleotide sequences and their application

The tetrahedral representation of DNA sequences and its applications have been studied by many authors. In this paper we study the isentropic equations of DNA sequences and their application. First, the DNA sequence entropy is introduced, and the entropy current and divergence are defined. Second, the isentropic equations are deduced and the isentropic curves on the three coordinate planes are respectively drawn by a computer. Third, an analysis is given on the entropy distribution on the coordinate planes. Finally, we make use of the results to discuss the relationship of the fastest increasing directions of the entropy for the cytochrome c genes of seven species.

Changes in intrahepatic portal hemodynamic in early stage hepatic abscesses

Color Doppler sonography was used to investigate the changes in intrahepatic portal hemodynamics in early stage hepatic abscesses (21 lesions). At time of patients' admission, 10 lesions measuring over 6 cm showed reverse flow from at least one of their corresponding segmental portal branches, but 11 lesions measuring 6 cm or less did not show this phenomenon. All portal branches with reverse flow eventually returned to a normal direction of flow after successful medication. In conclusion, a large early stage hepatic abscess may show temporary reverse portal flow on color imaging. Thus, a differential diagnosis of hepatic tumors with reverse portal flow should include early stage hepatic abscesses.

Pharmacology and efficacy of liposome-entrapped albendazole in experimental secondary alveolar echinococcosis and effect of co-administration with cimetidine

Encapsulation of the benzimidazole albendazole in multilamellar liposomes results in a preparation in which this normally insoluble anti-hydatid drug is well solublilized in aqueous media. The high entrapment efficiency observed (75-87%) and the stability of the formulation make this a promising delivery vehicle for improved chemotherapy with albendazole. In particular, the high degree of association with phospholipid may give rise to increased oral bioavailability. Oral administration of albendazole in liposomes led to increased concentration and/or altered metabolism of albendazole sulphoxide (ABZSX) in liver and/or plasma in non-infected Wistar rats. Results from experiments using cotton rats (Sigmodon hispidus) infected with metacestodes of Echinococcus multilocularis show that entrapment within liposomes clearly increases the uptake of albendazole via the oral route. This was reflected by increased levels of albendazole and the two major metabolites in plasma, liver and cyst homogenate when a dose of liposomal albendazole (35 mg/kg) was given orally compared to free albendazole at 50 mg/kg. There was a 75-94% reduction in biomass of the metacestode and a significant increase in survival time for the animals treated with liposome entrapped albendazole. A clear difference in distribution of albendazole and its metabolites in the liver and the metacestode tissues in the presence of cimetidine indicated that the latter has a profound effect on the metabolism of albendazole. There appeared to be a synergistic interaction between albendazole and cimetidine, since the metabolism of albendazole was markedly altered in the combined cimetidine/ liposome-albendazole group, and higher therapeutic effect was observed. These findings indicate potential both for improvement of treatment of larval E. multilocularis infection and for reduction of albendazole dose levels.

Neuronal Cdc2-like kinase: from cell cycle to neuronal function

Neuronal Cdc2-like kinase, Nclk, is a heterodimer of cyclin-dependent protein kinase 5 (Cdk5) and a 25-kDa essential regulatory subunit that is derived from a 35-kDa brain- and neuron-specific protein. This protein is called neuronal Cdk5 activator, p25/35nck5a. Nclk is one of the best characterized Cdc2 family kinases whose primary function is not cell cycle related. It has been suggested that this protein kinase plays important roles in neurocytoskeleton dynamics and its loss of regulation has been implicated in Alzheimer pathology. As a member of the Cdc2-like kinase family, Nclk shares many common properties with other members of the Cdc2-like kinase family. It also possesses unique characteristics that may be related to its distinct and noncell cycle related functions. The regulatory and functional properties of Nclk are reviewed in this communication.

Regulation of synaptic facilitation by postsynaptic Ca2+/CaM pathways in hippocampal CA1 neurons

1. Current- and voltage-clamp recordings with simultaneous field potential recordings were used to study the cellular and molecular mechanisms that contribute to synaptic facilitation at CA1 synapses in rat hippocampal slices. Microelectrodes used for intracellular recordings were also used to inject modulators of intracellular signal pathways into postsynaptic CA1 neurons. 2. Paired-pulse stimulation at constant stimulus intensity was used to analyze the relationship between the first evoked response (R1) and the absolute value of paired-pulse synaptic facilitation (R2-R1). The magnitudes of these two measures were inversely correlated. Compared with synapses that control motor functions, the synapses of CA1 pyramidal neurons did not exhibit accumulative synaptic facilitation during repetitive stimulation, which is often believed to be mediated by presynaptic residual Ca2+. 3. During studies on the cellular location of mechanisms contributing to synaptic facilitation, we observed that postsynaptic injections of 1,2-bis(2-aminophenoxy)-ethane-N,N,N',N'-tetra-acetic acid or [Ala286]CaMKII281-302 [a Ca2+/calmodulin-dependent protein kinase II (CaM-KII) inhibitor peptide] prevented the decreases in paired-pulse facilitation (PPF) and synaptic potentiation induced by elevating extracellular Ca2+. These results show that raising extracellular Ca2+ enhances synaptic transmission in part by activating postsynaptic Ca2+ signal pathways. 4. The injection of Ca2+/calmodulin (CaM) into postsynaptic neurons significantly decreased PPF in 50 of 57 experiments while inducing synaptic potentiation; the Ca2+/CaM-induced synaptic potentiation and PPF attenuation occluded subsequent high Ca(2+)-induced enhancements of synaptic transmission. The changes in PPF induced by postsynaptic injections of Ca2+/CaM were inversely correlated with R1 potentiation. 5. The decreases in PPF induced by postsynaptic Ca2+/CaM injections were prevented by coinjecting pseudosubstrate inhibitors or substrate peptides of CaM-KII and protein kinase C (PKC), and were reversed by subsequent application of cyclothiazide (a blocker of alpha-amino-3-hydroxy-5-methylisoxazole-4-proprionic acid receptor desensitization). 6. Our results reveal that postsynaptic Ca2+/CaM signal pathways can modulate synaptic facilitation in the CNS, and the activities of CaM-KII and PKC are involved in this modulation. The physiological significance of such modulation is that synaptic strength could be potentiated by activation of Ca2+/CaM pathways during integration of important sensory input (e.g., learning and memory), whereas decreases in synaptic facilitation may protect synaptic transmission during extreme stimulation so that neuronal signal mechanisms can more accurately code neural information.

Melioidosis: two indigenous cases in Taiwan

We report the first two indigenously acquired cases of melioidosis in Taiwan, diagnosed by positive culture and biochemically identified using the ID 32 GN system (BioMerieux Vitek Inc, Hazelwood, MO, USA). The first patient was a 75-year-old Chinese woman who had not travelled abroad since her arrival from mainland China (San-Tung province) 47 years ago. She presented with spontaneous bacterial peritonitis and hepatitis C-related liver cirrhosis with septic shock. Burkholderia pseudomallei (formerly Pseudomonas pseudomallei) was isolated from cultures of both blood and ascites fluid. The second patient, a 70-year-old Chinese man, presented with right lower lobar pneumonia complicated with empyema and septic shock. Blood cultures grew B. pseudomallei. Both patients had underlying diabetes mellitus; one also had liver cirrhosis and chronic renal failure, while the other had a renal stone. The first patient died of refractory septic shock prior to diagnosis. The second patient survived with the use of intravenous ceftazidime for 30 days, followed by oral amoxicillin-clavulanic acid for a further 3 months. These cases serve as a reminder to clinical physicians that melioidosis is now no longer exclusive to patients with a history of travel to endemic areas. A high index of clinical suspicion is required for early diagnosis and treatment in order to reduce the mortality and improve clinical outcome.

Longitudinal study of intrahepatic portal flow: a novel approach using Doppler technique

The present study investigates whether the application of the summation of portal blood flow (SPBF), measured from the left umbilical portion and the right anterior branch by Doppler, could be of use in the longitudinal study of intrahepatic portal flow or not. Forty-five subjects were divided into two groups. Group I subjects included males and post-menopausal females. Thirty-seven subjects (19 normal volunteers, 12 subjects with chronic hepatitis, six cirrhotics) were investigated by the more experienced doctor A at 9 day intervals for an intra-observer study. Among them, seven subjects (four normal volunteers, three with chronic hepatitis) were also investigated consecutively at 10 min apart by doctor B on days 1 and 10 for an interobserver study. Group II subjects included eight normal subjects with a regular menstrual cycle. They were investigated by doctor A during menstruation, mid-follicular, ovulatory and mid-luteal phases of the menstrual cycle to evaluate the possible impact of the menstrual cycle on SPBF measurement. The reproducibility of measurements was assessed by the coefficient of variation (CV) and the reproducibility coefficient. Data are expressed as mean +/- s.d. The CV of the SPBF for intra-observer and interobserver study were 4.88 +/- 3.36 and 4.19 +/- 2.53, respectively. All differences of SPBF were within their corresponding reproducibility limits. The results of SPBF measurements obtained from different phases of the menstrual cycle were variable. Only the comparison between the data obtained from mid-follicular and mid-luteal phases could demonstrate acceptable CV values (3.98 +/- 3.12%) and all the differences in SPBF measurements were within the repeatability limit. In conclusion, Doppler SPBF measurement may be useful in the longitudinal evaluation of intrahepatic portal flow changes.

Bronchial inflammation and the common cold: a comparison of atopic and non-atopic individuals

BACKGROUND

Cold virus infections are associated with asthma attacks and with increased bronchial responsiveness even in normal subjects. Possible mechanisms include epithelial damage, interaction with adhesion molecules or with T-helper cell subsets.

OBJECTIVE

To determine whether colds increase lower airway inflammation, comparing atopic with non-atopic normal subjects.

METHODS

Thirty healthy volunteers (15 atopic) took part. Baseline tests included viral serology, microbiological culture and polymerase chain reaction for rhinovirus infection (HRV-PCR), histamine bronchial provocation and bronchoscopy. Twenty subjects (eight atopic) underwent repeat tests when they developed a cold.

RESULTS

Forced expiratory volume in one second (FEV1) was significantly lower during colds (-0.19 L [95% confidence interval -0.10, -0.29], P = 0.0004) and there was a significant increase in bronchial responsiveness (+0.62 doublings of the dose-response slope [+0.24, +1.00], P = 0.003). Eight subjects (two atopic) had a diagnosed viral infection: two HRV, three coronavirus (HCV), one HRV + HCV, one parainfluenza III (PI) and one respiratory syncytial virus (RSV) (also Haemophilus influenzae). In biopsies, during colds, total eosinophils (EGI+) increased significantly (geometric mean 6.73-fold [1.12,40.46], P = 0.04). Activated eosinophils (EG2+) only increased significantly in the subgroup without diagnosed viral infection and particularly in atopic rhinitics. T-suppressor (CD8+) cells also increased significantly (median + 178.3 cells mm2, P = 0.004). Epithelial expression of intercellular adhesion molecule-1 (ICAM-1) expression increased in four atopic rhinitics during colds. Bronchial washings showed a significant increase in neutrophils (GM 1.53-fold [1.04,2.25], P = 0.02).

CONCLUSION

Lower airway inflammation was present in atopic and non-atopic normal subjects with colds. Atopic subjects differed in that they were less likely to have positive virological tests and were more likely to show activated eosinophilia in the lower airway, despite a similar spectrum of symptoms.

Neutrophils undergo apoptosis following ingestion of Escherichia coli

Apoptosis is a distinct mechanism by which eukaryotic cells die. Neutrophils (PMN) play a fundamental role in the systemic inflammatory response syndrome. Clearance of PMN during resolution of the acute inflammatory process occurs by apoptosis, but factors inducing this process are unknown. The aims of this study were to determine whether PMN ingestion of Escherichia coli would result in PMN apoptosis and whether the mechanism was related to the respiratory burst. PMN from 10 healthy volunteers were cultured with different ratios of PMN:E. coli (1:0 to 1:25) for 12 h. Apoptosis was then assessed by propidium iodide DNA staining, morphology, gel electrophoresis, and Fc gamma RIII expression. There was a significant induction of PMN apoptosis on incubation with E. coli at a ratio of 1:10 and 1:25 PMN:E. coli as well as decreases in Fc gamma RIII. This correlated with increased ingestion of FITC-labeled E. coli and intracellular reactive oxygen intermediates after a 2-h coculture. To clarify the role of reactive oxygen intermediates in E. coli-induced PMN apoptosis, we assessed the effects of the antioxidants catalase, DMSO, glutathione, and N-acetylcysteine. There was a significant decrease in E. coli-induced PMN apoptosis on incubation with DMSO (1.0%), glutathione (25 mM), and N-acetylcysteine (25 mM) compared with control PMN:E. coli. This study demonstrates for the first time that E. coli induces PMN apoptosis through an oxygen-dependent mechanism. The removal of effete PMN by the process of apoptosis rather than necrosis may be teleologically beneficial during Gram-negative septicemia.