A comparative study of nonoperative versus operative treatment of developmental dysplasia of the hip in patients of walking age

We retrospectively reviewed our results of treatment of two groups of children with developmental dysplasia of the hip (DDH) aged between 13 and 17 months. The nonoperative group consisted of 16 patients (17 hips) who were treated by closed reduction and casting with or without skin traction. There were four hips with mild degrees of avascular necrosis, and one hip with a failed reduction. Before further treatment, there were one hip in Severin class I, nine in class III, six in class IV, and one in class VI. Subsequent open reduction or pelvic osteotomy was required in those hips with failed reduction and residual dysplasia. The operative group consisted of 32 patients (32 hips). Open reduction and Salter osteotomy were performed without preoperative traction. There was one hip with redislocation due to improper use of a short spica and two hips with a mild degree of avascular necrosis. In > 2 years and 3 months of follow-up, 13 hips were in Severin class I, 18 in class II, and one in class III. The treatment time was significantly shortened in the operative group. We conclude that neglected DDH in patients of walking age can be safely and effectively treated by open reduction plus Salter osteotomy.

Neuronal Cdc2-like kinase (Nclk) binds and phosphorylates the retinoblastoma protein

The tumor suppressor retinoblastoma protein (RB) plays a central role in cellular growth regulation, differentiation, and apoptosis. Phosphorylation of RB results in a consequent loss of its ability to inhibit cell cycle progression. However, how RB phosphorylation might be regulated in apoptotic or postmitotic cells, such as neurons, remains unclear. Here we report that neuronal Cdc2-like kinase (Nclk), composed of Cdk5 and a neuronal Cdk5 activator (p25(nck5a)), can bind and phosphorylate RB. Since RB has been shown recently to associate with D-type G1 cyclins and viral oncoproteins through a common peptide sequence motif of LXCXE, Nclk binding may be mediated by a related sequence motif (LXCXXE) found in p25(nck5a). We demonstrate (i) in vitro binding of bacterially expressed p25(nck5a) to a GST-RB fusion protein, (ii) coprecipitation of GST-RB and reconstituted Cdk5.p25(nck5a), and (iii) phosphorylation of GST-RB by bacterially expressed Cdk5.p25(nck5a) kinase and by Cdk5.p25(nck5a) kinase purified from bovine brain. Finally, we show that immunoprecipitation of RB from embryonic mouse brain homogenate results in the coprecipitation of Cdk5 and that Cdk5 kinase activity is maximal during late embryonic development, a period when programmed cell death of developing neurons is greatest. Taken together, these results suggest that Nclk can bind to and phosphorylate RB in vitro and in vivo. We infer that Nclk may play an important role in regulating the activity of RB in the brain, including perhaps in apoptosing neurons.

A continuous method for measuring calpain activity

A simplified methodology for assaying the caseinolysis by calpains was developed. This methodology, including the incubation of calpain with casein and direct measurement of the absorbance at 500 nm, is based on the turbidity of the reaction mixture caused by the aggregation of hydrolysates during the reaction. Unlike the typical caseinolysis assay, this novel assay does not need to separate the substrate from hydrolysates and can be continuously monitored in visible wavelength range. The activity of calpain is expressed by the maximum reaction velocity (delta A500/min) at 25 degrees C).

Allergen-irritant interaction and the role of corticosteroids

Studies of exposure to air pollutants, such as ozone and nitrogen dioxide (NO2) +/- sulphur dioxide (SO2), have demonstrated that these agents, either individually or in combination, increase the airway response of both asthmatics and allergic rhinitics to inhaled allergen. Other studies have demonstrated that exposure to these pollutants significantly increased the levels of eosinophil cationic protein (ECP) in the nasal secretions of both asthmatics and allergic rhinitics, suggesting that pollutants may prime eosinophils for subsequent activation by allergen. More recently, our studies have demonstrated that treatment with inhaled corticosteroids, such as fluticasone propionate, significantly attenuated pollution+ allergen-induced release of ECP in allergic rhinitics. Although the mechanisms underlying the potentiating effects of pollutants on allergen-induced changes in the airways of allergic individuals are not fully understood, in vitro studies have suggested that airway epithelial cells may play an important role, since they can synthesize a variety of cytokines and adhesion molecules which influence the activity of eosinophils and other inflammatory cells. Studies of nasal epithelial cells cultured from biopsies of atopic rhinitic and atopic non-rhinitic individuals have shown that they constitutively release significantly greater quantities of pro-inflammatory cytokines than nasal epithelial cells of non-atopic individuals, and that the release of these cytokines is greater from cells of atopic rhinitics during the pollen season. Furthermore, exposure of the cells of rhinitics to ozone led to an even greater release of these cytokines, and this effect was attenuated by treatment with fluticasone propionate and beclomethasone dipropionate.

[Study of the effects of pulse magnetic fields on hemorrheology of human body]

The results show that middle shear specific viscosity and reductive viscosity (P<0.05), low shear specific viscosity and reductive viscosity of whole blood (P<0.01) decreased significantly in experimental group after 9-day of pulse magnetic fields, comparing with control group, high shear specific viscosity, low shear reductive viscosity (P<0.05) and middle and low shear specific viscosity (P<0.01) of whole blood in experimental group were lower after exposed than before exposed to pulse magnetic fields. The results suggest that the pulse magnetic fields may reduce specific and reductive viscosity of whole blood in human body.

Cryptococcal meningitis and primary CNS lymphoma in a patient with acquired immunodeficiency syndrome: a case report

This report describes a case of cryptococcal meningitis as the initial manifestation of acquired immunodeficiency syndrome (AIDS). During the admission, computed tomography (CT) of brain revealed multiple lesions with ring-enhancement over the cerebellum, frontal and temporal lobes. Autopsy findings showed diffuse cryptococcal meningoencephalitis and central nervous system (CNS) lymphoma forming multiple round ring abscesses. The case demonstrated that opportunistic cryptococcal infection and primary CNS lymphoma may coexist in a patient with AIDS.

Clinical utility of color Doppler sonography in the differentiation of hepatocellular carcinoma from metastases and hemangioma

The clinical utility of color Doppler sonography in the differentiation of hepatocellular carcinoma from metastases and hemangioma was investigated in 72 hepatocellular carcinomas (80 lesions), 30 metastases (82 lesions), and 39 hemangiomas (54 lesions). Overlaps of color patterns were found among hepatocellular carcinoma, metastases and hemangioma. Pulsatile waves from lesions with the basket, vessels within tumor, or spot patterns, or lesions measuring less than 3 cm with detectable signals, did not favor the diagnosis of hemangioma. In conclusion, color Doppler sonography can aid in the differentiation of hepatocellular carcinoma from hemangioma but may be unreliable in the differentiation of hepatocellular carcinoma from hypervascular metastases.

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. Basehne 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 (‐0.19L [95% confidence mterval ‐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 (EG1⁺) increased significantly (geometric mean 6.73‐fold [1.12,40.46], P=O.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.

Developmental alteration of the expression and kinase activity of cyclin-dependent kinase 5 (Cdk5)/p35nck5a in the rat retina

Neuronal Cdc2-like kinase has been purified from the bovine brain as a proline-directed serine/threonine kinase. This kinase is a heterodimer of Cdk5 and p35nck5a and influences neuronal maturation or sprouting in the normal brain. In this study, we showed the expression of Cdk5/p35nck5a kinase in the developing rat retina. The expression of Cdk5 and p35nck5a increased between 1 week and 3 weeks after birth. These expression levels were most prominent from 2 weeks to 3 weeks after birth and decreased after 4 weeks. The developmental change of Cdk5/p35nck5a kinase activity coincided with those of the expression of p35nck5a and Cdk5. An immunohistochemical study showed that Cdk5 was expressed in the ganglion cells and in some cells in the inner nuclear layer at an early stage. With retinal development, Cdk5 was expressed in the inner plexiform layer also. In the adult, the expression of Cdk5 was restricted to the inner plexiform layer and to some cells in the inner nuclear layer. These changes of localization in the developing retina were very close to those of B-50/GAP-43. On the other hand, the expression of p35nck5a was restricted to the soma of the neuron in the developing retina. This subcellular localization in the developing retina agreed with that in the developing rat brain. The expression levels of Cdk5 and p35nck5a in retina of rats raised from fetus to 3 weeks after birth in darkness were 36% and 40% respectively, of the baseline for control rats. Moreover, the kinase activity in rats raised in darkness was lower than that in control rats. These data suggest that Cdk5/p35nck5a may play a role in neuronal plasticity in the developing rat retina.

Taurine attenuates nitric oxide- and reactive oxygen intermediate-dependent hepatocyte injury

OBJECTIVE

To evaluate the potential role of the semi-amino acid taurine in the prevention of hepatocyte (HC) apoptosis and necrosis mediated by nitric oxide (NO) and reactive oxygen intermediates.

DESIGN

Isolated rat HCs were cultured with lipopolysaccharide (LPS), antioxidants, taurine, and sodium nitroprusside to examine the effect of these agents on HC injury.

RESULTS

Lipopolysaccharide, in the presence of antioxidants, led to HC apoptosis, while LPS alone failed to induce HC apoptosis. Taurine significantly attenuated LPS plus antioxidant-mediated HC apoptosis, and this correlated with taurine-mediated NO inhibition. Taurine also significantly reduced LPS-mediated hepatocellular enzyme release and HC necrosis, and this correlated with HC free radical and peroxynitrite inhibition. However, taurine did not prevent sodium nitroprusside-mediated HC apoptosis and necrosis.

CONCLUSIONS

Taurine attenuates HC apoptosis and necrosis through inhibition of both NO and reactive oxygen intermediate. While taurine acts directly as an antioxidant, its effects on NO may occur at the messenger RNA level. Our findings indicate a potential prophylactic and therapeutic role for this amino acid during systemic inflammatory response syndrome.

Malakoplakia of the prostate forming a fistulous tract to rectum: a case report

Malakoplakia is a rare lesion of granulomatous inflammation which mainly affects urinary bladder but may involve other parts of the body. Differentiation from neoplastic process is often difficult due to its tumorous gross appearance and similarity to carcinoma microscopically. Malakoplakia of the prostate is even rare. We present a case of prostatic malakoplakia masquerading as a rectal tumor due to formation of a fistulous tract to the rectal muscular layers accompanied with ulceration of the rectal mucosa. Its clinical course is different from those of most reported cases, while the outcome is as satisfactory as in usual cases.

Treatment of carbon monoxide poisoning with hyperbaric oxygen

BACKGROUND

Carbon monoxide poisoning is a major cause of accidental morbidity and mortality in Taiwan. Utilization of hyperbaric oxygen in severely carbon monoxide intoxicated patients has been investigated widely. The object of this study was to determine the nature of carbon monoxide poisoning and to evaluate the effect of hyperbaric oxygen therapy for such patients.

METHODS

Retrospective analysis of 34 consecutive carbon monoxide intoxicated patients by review of medical records and clinical follow-up for the past three years.

RESULTS

Subjects were 10 males and 24 females, aged 12 to 82 years. The source of the poisoning in 25 cases was faulty-operating heating systems; in 4, incomplete combustion of automobile engine; in 3, use of alternative sources of energy for indoor cooking and heating; in 2, smoke inhalation in fire accidents. All had neurologic symptoms; five also had cardiovascular symptoms and one developed delayed neurologic sequelae. The group with poor outcome after hyperbaric oxygen therapy (n = 10) had higher serum CK values, lower Glasgow coma scale, longer delay in the first aid at emergency service and longer delay in provision of hyperbaric oxygen therapy.

CONCLUSIONS

It was concluded that hyperbaric oxygen therapy is an effective method in treating carbon monoxide intoxicated patients. Understanding the pathogenesis of carbon monoxide poisoning and indications for hyperbaric oxygen therapy will help physicians manage such patients earlier and more adequately. Information on currently available hyperbaric facilities in Taiwan is necessary for timely transfer.

Selective defects in the development of the fetal and adult lymphoid system in mice with an Ikaros null mutation

Mice homozygous for an Ikaros null mutation display distinct defects in the development of fetal and adult lymphocytes. Fetal T lymphocytes, and fetal and adult B lymphocytes and their earliest progenitors are absent. Postnatally, hematopoietic stem cells give rise to thymocyte precursors that undergo aberrant differentiation into the CD4 lineage and clonal expansion. The lack of NK cells and some gamma delta T cell subsets and a large reduction in thymic dendritic APCs suggest that Ikaros is essential for establishing early branch points in the postnatal T cell pathway. The lymphoid defects detected in Ikaros null mice reveal critical molecular differences between fetal and postnatal hematopoietic progenitors that dictate their ability to give rise to T cells. These studies also establish Ikaros as a tumor suppressor gene acting during thymocyte differentiation. Phenotypic comparison of this null mutation with a severe dominant-negative Ikaros mutation identifies molecular redundancy in the postnatal hemolymphoid system.

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.