Immune function of thyroid stimulating hormone and receptor

Thyroid stimulating hormone (TSH) is a central component of the hypothalamus-pituitary-thyroid axis. Although TSH is known for its important biological effects as a neuroendocrine used to regulate thyroid hormone activity and subsequent metabolic functions, TSH also has been shown to be produced and used by cells ofthe mammalian immune system. Moreover, recent findings have linked the use of TSH by cells of the immune system in humans and mice to a group of monocytic cells and lymphocytes--primarily dendritic cells, macrophages, and subset of naïve peripheral T cells. Other studies have demonstrated the capacity of dendritic cells and monocytes to produce biologically active TSH, thereby pointing to a process of paracrine or autocrine TSH-mediated communication during the earliest stages of an immune response to antigen. In this article, these and other features of TSH immune-endocrine interactions are discussed in the context of an intrinsic TSH immunological pathway. Additionally, a hypothesis is proposed in which TSH produced by cells of the immune system during acute antigen exposure plays a dual role, consisting on the one hand of TSH communication during antigen-driven immune activation while concomitantly serving to regulate physiological homeostasis by modulating and adjusting thyroid hormone activity.

Multiple levels of activation of murine CD8(+) intraepithelial lymphocytes defined by OX40 (CD134) expression: effects on cell-mediated cytotoxicity, IFN-gamma, and IL-10 regulation

The involvement of OX40 (CD134) in the activation of CD8(+) intestinal intraepithelial lymphocytes (IELs) has been studied using freshly isolated IELs and in vitro CD3-stimulated IELs. Although freshly isolated CD8(+) IELs exhibited properties of activated T cells (CD69 expression and ex vivo cytotoxicity), virtually all CD8(+) IELs from normal mice were devoid of other activation-associated properties, including a lack of expression of OX40 and the ligand for OX40 (OX40L) and an absence of intracellular IFN-gamma staining. However, OX40 and OX40L expression were rapidly up-regulated on CD8 IELs following CD3 stimulation, indicating that both markers on IELs reflect activation-dependent events. Unlike IELs, activated lymph node T cells did not express OX40L, thus indicating that OX40-OX40L communication in the intestinal epithelium is part of a novel CD8 network. Functionally, OX40 expression was exclusively associated with IELs with active intracellular IFN-gamma synthesis and markedly enhanced cell-mediated cytotoxicity. However, OX40 costimulation during CD3-mediated activation significantly suppressed IL-10 synthesis by IELs, whereas blockade of OX40-OX40L by anti-OX40L mAb markedly increased IL-10 production. These findings indicate that: 1) resident CD69(+)OX40(-) IELs constitute a population of partially activated T cells poised for rapid delivery of effector activity, 2) OX40 and OX40L expression defines IELs that have undergone recent immune activation, 3) OX40(+) IELs are significantly more efficient CTL than are OX40(-) IELs, and 4) the local OX40/OX40L system plays a critical role in regulating the magnitude of cytokine responses in the gut epithelium.

Crystallization and preliminary crystallographic studies of antibacterial polypeptide LCI expressed in Escherichia coli

LCI is a type of novel antibacterial polypeptide secreted by a Bacillus subtilis strain. It consists of 47 residues with a molecular weight of 5468 Da. Using bioengineering, LCI was expressed in Escherichia coli DH5alpha with recombinant plasmid pBVAB16. It was crystallized using PEG 4000 as a precipitant. The crystal belongs to space group P6(2)22 or P6(4)22, with unit-cell parameters a = b = 29.30, c = 187.09 A, and diffracts to 2.44 A. A set of diffraction data to 2.8 A was collected.

Effective treatment of small murine hepatocellular carcinoma by dendritic cells

Hepatocellular carcinoma (HCC) is a common malignancy with a poor prognosis. This investigation examined whether dendritic cell-based immunotherapy can treat murine HCC effectively. Bone marrow-derived dendritic cells were propagated from C57BL/10J mice in GM-CSF (4 ng/mL) and interleukin (IL)-4 (1,000 micro/mL). The dendritic cells were pulsed with a Hepa1-6 lysate overnight and employed to treat murine HCC. For in vivo study, HCC was created by inoculation of hepa1-6, 5 x 10(5) cells, in the flank of C57BL/10J mice. HCC were categorized into small (3 x 3-mm) and large (5 x 5-mm) tumors. These HCC were treated by dendritic cells intravenously, twice at weekly intervals. The results revealed that lymphocytes could be gathered around small HCC after administration of Hepa1-6 lysate-pulsed dendritic cells. Seven of 12 (58.3%) small HCC could be eradicated completely by dendritic cell-based immunotherapy, and 33.3% of the small tumors responded to immunotherapy partially which were held in a stable condition for 34.0 +/- 7.4 days before the tumors regrew. For large HCC, lymphocytes did not gather around the tumors, and the tumors cannot be eradicated effectively by dendritic cells. However, dendritic cell-based immunotherapy could slow down the growth rate of large tumors (116.2 +/- 91.4 mm(3) vs. 234.0 +/- 149.1 mm(3) of the control on day 7, P =.043; and 280.3 +/- 224.7 mm(3) vs. 870.0 +/- 418.9 mm(3) of the control on day 17, P <.001). Conclusively, dendritic cells pulsed with a Hepa1-6 lysate can be employed to treat small HCC in vivo effectively. However, the efficacy of dendritic cell-based immunotherapy decreases while tumors grow.

Changes in the performance of schedule-induced polydipsia (SIP) in rats after arecoline and amphetamine treatments

This study investigated the performance of schedule-induced polydipsia (SIP) rats in novel or intermittent-reward SIP sessions after arecoline (AREC) and amphetamine sulfate (AMPH) treatments. Either automatic monitors or observers extensively examined the functional changes of parameters in behavioral performance followed by increasing drug dosage. The parameters included locomotion and stereotyped behaviors in the novel sessions; schedule-induced licks, water intake, schedule-dependent nose-pokes, pellets earned and stereotyped behaviors of the facultative stage in the SIP sessions. It was found that when the rats received AMPH (0.5 - 2.0 mg/kg) but not AREC (0.1 - 1.6 mg/kg) in the novel sessions, locomotion increased in a dose-dependent manner. However, when AREC (0.8 mg/kg) and AMPH (1.0 mg/kg) were both given, the effect of AMPH on locomotion was significantly attenuated. In the SIP sessions, a single injection of AMPH increased the number of schedule-dependent nose-pokes at a dose of 1.0 mg/kg, whereas it decreased the number of schedule-induced licks and the amount of water intake at a dose of 2.0 mg/kg. On the other hand a single injection of AREC caused no operant behavior changes at doses below 0.8 mg/kg. However, when the dose was increased to over 0.8 mg/kg (1.6 mg/kg), the number of schedule-induced licks and water intake increased, but the number of schedule-induced nose-pokes decreased. The effects of large doses of AREC on SIP were attenuated after co-administration of scopolamine (0.1 mg/kg), a muscarinic receptor antagonist. Furthermore, the effects of AMPH on SIP performance were not changed by co-administration of AREC at a dose of 0.8 mg/kg. These results are discussed based on the hypothesis that combined utilization of the main component in chewing betel quid, AREC, and AMPH may yield changes of AMPH-induced psychomotor responses in a special environmental context.

Rapid and transient reduction in circulating thyroid hormones following systemic antigen priming: implications for functional collaboration between dendritic cells and thyroid

The thyroid hormones T(3) (tri-iodothyronine) and T(4) (thyroxine) are disseminated throughout the body via the circulation and are maintained across a range of physiological concentrations under the control of thyroid-stimulating hormone (TSH). T(3) (and T(4) after conversion to T(3)) influences many biological activities, including gene expression and protein synthesis, though little is known about the nature of pituitary-thyroid immune interactions. In the present study we show that serum T(3) and T(4) levels are sharply but transiently reduced during the first 24 h of systemic antigen exposure and that this is followed by suppressed levels of free T(4), after which there is rapid recovery to normal levels. Splenic dendritic cells, depending upon the stage of maturation/activation, were found to be a rich source of TSH, and CD11c(+) cells with dendritic cell morphology were present in the thyroid 1-3 days after antigen exposure. Moreover, antigen priming of hypophysectomized mice that are unable to make pituitary-derived TSH resulted in significant increases in circulating T(4), implying that compensation in the drop in thyroid hormones can be regulated from extrapituitary sources. These findings thus identify a novel set of immune-endocrine interactions that transpire during the early phase of antigen exposure, and they suggest that under appropriate conditions the immune system directly participates in the process of maintaining physiological homeostasis by contributing to the regulatory control of thyroid hormone activity.

Alpha-lactose monohydrate single crystals as hosts for matrix isolation of guest biopolymers

Single crystals of alpha-lactose monohydrate show a remarkable tendency to include biopolymers, such as proteins, oligonucleotides and dextrans, within the growing lattice. Glycosylation increased the amount of protein contained within the crystals. The guest molecules were found only within the (010) growth sector of the hatchet shaped crystals, thereby binding preferentially to one of the seven developed crystal faces. The topographical features of the active surface are described.

Structure-activity studies of ground- and transition-state analogue inhibitors of cyclophilin

Peptidyl-prolyl isomerases (PPIases) are ubiquitous cellular enzymes that play roles in cellular signaling and protein folding. In addition, these proteins are the receptors for the widely used immunosuppressants cyclosporin A and FK506. We report the first structure-activity studies of de novo designed inhibitors of cyclophilin, the cellular target of cyclosporin A. Our mechanism-based inhibitors were modeled on the ground- and transition-state structures of proline-containing peptides, the natural substrates of the enzyme. Both ground-state analogues 1 and transition-state analogues 2 were prepared as single enantiomers from L-proline following a "self-reproduction of chirality" procedure. The binding affinities of the analogues for the active site of cyclophilin were measured by a fluorescence perturbation assay. While the transition-state analogues 2 did not display significant avidity for the active site (K(d) = 77 microM for 2b), several ground-state analogues bound to the enzyme with low micromolar affinity (K(d) = 1.5 microM for 1e). These results proclaim that properly designed small molecular weight molecules can form strong complexes with cyclophilin and may find use as probes in cell biology and as therapeutic agents.

Treatment of neuroleptic malignant syndrome with subcutaneous apomorphine monotherapy

A 20-year-old psychiatric patient receiving haloperidol treatment developed acute-onset fever, rigidity, and mental changes. Subcutaneous apomorphine was given alone for treatment. The patient had rapid clinical improvement after the treatment. Serial blood examinations showed decline and subsequent normalization of the creatine phosphokinase levels.

CD43 potentiates CD3-induced proliferation of murine intestinal intraepithelial lymphocytes

The involvement of CD43 in cell proliferation of murine intestinal intraepithelial lymphocytes (IEL) has been studied in in vitro CD3-stimulated cell cultures. In the presence of either IL-2 or IL-15, CD3 stimulation of IEL resulted in low levels of proliferation as measured by thymidine incorporation, whereas no proliferation occurred upon CD3 stimulation in the absence of cytokines. The combination of both cytokines to IEL cultures synergistically enhanced CD3-induced proliferation by approximately threefold that of cultures supplemented with either cytokine alone. Most importantly, however, proliferation of IEL was significantly greater when CD3 stimulation occurred in conjunction with CD43 triggering, indicating that CD43 functions as a coactivational signal for murine IEL. These findings indicate that a spectrum of potential proliferative responses exist among murine IEL depending on the types and combinations of signals received, and that because under normal conditions murine IEL are largely devoid of CD28 expression, a classical T-cell coactivational molecule, the capacity for high-level IEL proliferation may reside with CD43.

Gaseous nitric oxide-induced 8-nitroguanine formation in human lung fibroblast cells and cell-free DNA

A time- and dose-dependent increase in 8-nitroguanine (8-NO(2)-G) was observed in human lung fibroblast cells (MRC-5) after treatment with gaseous NO-saturated buffer. It was also found that treatment with the inhibitor of inducible nitric oxide synthase (iNOS), N(G)-nitro-l-arginine methyl ester, significantly reduced the 8-NO(2)-G level in the gaseous NO-saturated buffer-treated MRC-5 cells. These results provide evidence indicating that NO gas causes DNA damage in mammalian cells, which involves the activation of iNOS and the subsequent generation of endogenous NO. On the other hand, a time- and dose-dependent increase in 8-NO(2)-G was also observed while DNA (isolated from MRC-5 cells) was incubated with gaseous NO-saturated buffer. These results suggest that part of the 8-NO(2)-G formation was due to direct modification of gaseous NO on DNA. Furthermore, an increase in nitrite concentration was found in both cell-free and MRC-5 cell-conditioned medium treated with gaseous NO-saturated buffer. Collectively, gaseous NO induced DNA damage by forming 8-NO(2)-G, a modification performed directly by the treated gaseous NO and indirectly by the following induction of endogenous NO. This effect might be an important pathway in genotoxicity of nitric oxides, and 8-NO(2)-G could act as a specific marker for DNA damage induced by gaseous NO, a common contaminatant in air pollution and cigarette smoke.

Analysis of codon usage patterns of bacterial genomes using the self-organizing map

Codon usage varies both between organisms and between different genes in the same organism. This observation has been used as a basis for earlier work in identifying highly expressed and horizontally transferred genes in Escherichia coli. In this work, we applied Kohonen's self-organizing map to analysis of the codon usage pattern of the Escherichia coli, Aquifex aeolicus, Archaeoglobus fulgidus, Haemophilus influenzae RD:, Methanococcus jannaschii, Methanobacterium thermoautotrophicum, and Pyrococcus horikoshii genomes for evidence of highly expressed genes and horizontally transferred genes. All of the analyzed genomes had a clear category of horizontally transferred genes, and their apparent percentages ranged from 7.7% to 21.4%. The apparent percentage of highly expressed genes ranges from 0% to 11.8%. A clustering of average codon usage of main gene categories of the seven genomes showed an interesting mixing of gene classes in four thermophilic/hyperthermophilic organisms, A. aeolicus, A. fulgidus, M. thermoautotrophicum, and P. horikoshii, which suggests possible origins of their horizontally transferred genes as well as the need for adaptation to a specific environment. Further classification of the three gene categories in E. coli and H. influenzae according to gene function revealed that genes involved in communication (such as regulation and cell process) and structure (cell structure and structural proteins) are more likely to be horizontally transferred than are genes involved in information (transcription, translation, and related processes) and in some groups of energy (such as energy metabolism and carbon compound catabolism).

Tie-1 tyrosine kinase is an independent prognostic indicator for invasive breast cancer

Receptor tyrosine kinases are known to be involved in the growth, progression and metastasis of solid tumors. We investigated the relationship between tie-1 expression and progression of invasive ductal breast carcinoma with immunohistochemical analysis. Tie-1 protein was detected in the microvessel endothelial cells and cytoplasm of tumor cells. The tumor size and stage were significantly associated with the expression of tie-1, which portends a worse 5-year disease-free status (39.3% v 59.2%, p = 0.07) and overall survival rate (67.3% v 93%, p = 0.02) than those without tie-1 expression. Multivariate analysis demonstrated that larger tumor size, presence of lymph node metastasis and tie-1 expression were independent prognostic parameters, both in 5-year disease-free survival and overall survival. Patients with lymph node metastases and tie-1 expression had the worst 5-year disease-free survival (0%) and overall survival (42.4%) compared to those without tie-1 expression (50.2%, 85%). In lymph node negative patients, those without tie-1 expression had better 5-year disease-free survival and overall survival (72.9%, 100%) compared to those with tie-1 expression (65.5%, 87.7%). We conclude that tie-1 expression is an independent prognostic factor for invasive ductal breast carcinoma, adversely affecting survival of breast cancer patients with positive nodes to a significant extent.

Determination of beryllium and selenium in human urine and of selenium in human serum by graphite-furnace atomic absorption spectrophotometry

For human urine beryllium (Be), each sample (500 microl) was diluted (1+1) with Nash reagent (containing 0.2% (v/v) acetylacetone and 2.0 M ammonium acetate buffer at pH 6.0) and then a 20-microl volume of Triton X-100 (0.4%, v/v) aqueous solution was added. An aliquot (10 microl) of the diluted urine mixture was introduced into a graphite cuvette and was atomized according to a temperature program. The method detection limit (MDL, 3sigma) for Be was 0.37 microg/l in the undiluted urine sample and the calibration graph was linear up to 65.0 microg/l. Calibration graphs were prepared by the standard addition method. Accuracies of 98.6-102% were obtained when testing standard reference material (SRM 2670) freeze dried human urine samples. Precision (relative standard deviation, RSD) for urine Be was < or = 2.3% (withinrun, n = 5) and was < or = 3.0% (between-run, n = 3). For human urine and serum selenium (Se), samples (100 microl) were diluted with HNO3 (0.2%, v/v) to make a (1+1) dilution for urine analysis or a (1+4) dilution for serum analysis. An additional aliquot (10 microl) of Triton X-100 (0.1%, v/v) was added to each 200 microl of (1+1) diluted urine (or 20 microl of the Triton X-100 was added to each 500 microl of (1+4) diluted serum) sample. After the diluted sample mixture (10 microl) was introduced into a graphite cuvette, the corresponding chemical modifier (10 microl, containing Ni2+ + Pd + NH4NO3 in HNO3 (0.2%, v/v)) was added to it and the mixture was atomized. The MDL (3sigma) for Se in urine and in serum was 4.4 and 21.4 microg/l in undiluted sample, respectively, and the calibration graphs were linear up to 150 and 400 microg/l. Accuracies of urine Se were 98.9 - 99.4% by testing SRM 2670 (NIST) urine standards with RSD (between-run, n = 3) within 2.9%; and that of serum Se was 97.2% when testing a certified second-generation human serum (No. 29, #664) with RSD (between-run, n = 3) of 1.4%. The proposed method can be applied easily, directly, and accurately to the measurement of Be and Se in real samples (including six urine Se and four serum Se from patients of Blackfoot Disease in Taiwan).

Mutations of p53 gene in human colorectal cancer: distinct frameshifts among populations

We analyzed 57 p53 gene mutations in 181 colorectal cancer patients in Taiwan and compiled data on 475 independent p53 mutations in 1,156 primary colorectal cancer patients worldwide between 1992 to 1998. Transitions at the CpG sites were observed in 31 (54%) and 232 cases (49%), respectively. Frameshift mutations occurring within exons were observed in 11 (20%) and 50 cases (10%), respectively. Among the various populations studied, colorectal cancer in Taiwan had the lowest p53 mutation rate (31%), highest frequency (20%) of frameshift mutations and the second lowest rate (13%) of transversion mutation. Based on their relation to the base runs, the 61 frameshift mutations could be grouped into 4 subclasses. After corrections were made for differences in the base number in a run, the relative mutational frequency at a base run was found to be 9- to 47-fold over that in the no-run residues. The p53 frameshift mutational spectrum found in the cases in Taiwan, with respect to hotspot sequence, was significantly different from those in the selected database (p = 0.008). These data support that the patterns of high frequency of transitions at CpG sites and low frequency of transversions in base substitutions in the p53 gene are similar regardless of patient origin. However, these data also illustrate that frameshift mutations in the p53 gene in colorectal cancer patients are sequence dependent and are distinct among populations.

In-situ EXAFS study of copper in the electrokinetic remediation process

The speciation of copper in the early stage of the electrokinetic remediation (EKR) process has been studied by extended X-ray absorption fine structure (EXAFS) spectroscopy in the present work. By in-situ EXAFS, we found that copper in a contaminated soil possessed a Cu-O bond distance of 1.98 A with a coordination number (CN) of 5.8. In the second shell, the bond distance of Cu-(O)-Cu was 2.87 A with a CN of 6.4. However, possibly due to the fact that incompact copper atoms in the outer shells were distorted by EKR, the Cu-(O)-Cu (2nd shell) bond distance and the CN of copper in the contaminated soil decreased by 0.08 A and 5.4, respectively in the early stage of the EKR process. Interestingly, after prolonging the contact time to about 80 minutes, the 1st-shell copper atoms were also perturbed by EKR. This work is an example of usefulness of the in-situ EXAFS spectroscopy for detailed studies of the speciation of copper in the contaminated soil during EKR process.

Speciation of As in the blackfoot disease endemic area

Speciation of arsenic (As) in well water and contaminated soil in the blackfoot disease endemic area has been studied by extended X-ray absorption fine structural (EXAFS) spectroscopy in the present work. Experimentally, we found that arsenic in the well water possessed an As-O bond distance of 1.72 A with a coordination number (CN) of 4.3. In the blackfoot disease area, arsenic with a high oxidation state (As(V)) was also observed in the contaminated soil. In the early stage (after 90 minutes) of the electrokinetic remediation (EKR) of the contaminated soil, the in-situ EXAFS data indicated that the CN of As-O (1st shell) decreased slightly, that may be due to the perturbation of the incompact As atoms in the outer shells by EKR.

Increased expression of iNOS and c-fos via regulation of protein tyrosine phosphorylation and MEK1/ERK2 proteins in terminal bronchiole lesions in the lungs of rats exposed to cigarette smoke

Epidemiological evidence suggests that smoking is a major cause of human lung cancer. However, the mechanism by which cigarette smoke induces the cancer remains unestablished. To evaluate the effects of cigarette smoke on the expression of inducible nitric oxide synthase (iNOS), nuclear protooncogenes and related mitogen-activated protein kinases (MAPKs) in rat lung tissue, a histopathological study of the effects of gas-phase cigarette smoke on rat lung tissue were carried out. The terminal bronchioles were found to be infiltrated predominantly by lymphocytes in the peribronchiolar region and a mild to moderate degree of emphysema was noted in the alveolar spaces. The terminal bronchioles also showed marked lipid peroxidation, dilatation, and peribronchiolar fibrosis. Immunohistochemical evaluation showed that the expression of iNOS, NF-kappa B, MAPKs (MEK1, ERK2), phosphotyrosine protein and c-fos was increased in the terminal bronchioles but protein kinase C (PKC), MEKK-1, c-jun, p38 and c-myc showed no change. These results provide evidence to suggest that exposure to cigarette smoke results in oxidant stress which leads to the stimulation of iNOS and c-fos together with the induction of protein tyrosine phosphorylation and MEK1/ERK2 which in turn may promote lung pathogenesis.

Sequencing and amplified restriction fragment length polymorphism analysis of ribonucleotide reductase large subunit gene of the white spot syndrome virus in blue crab (Callinectes sapidus) from American Coastal Waters

In the present study, the existence of white spot syndrome virus (WSSV) in blue crab (Callinectes sapidus) collected from 3 different American coastal waters (New York, New Jersey, and Texas) was confirmed by 2-step diagnostic polymerase chain reaction and in situ hybridization analysis. When geographic isolates were also compared using a gene that encodes the WSSV ribonucleotide reductase large subunit RR1 (WSSV rr1), a C(1661)-to-T point mutation was found in the New Jersey WSSV isolated. This point mutation, which resulted in the creation of an additional RsaI endonuclease recognition site, was not found in the WSSV from the New York and Texas blue crab samples, or in the WSSV Taiwan isolate, or in any of the other WSSV geographical isolates for which data are available. WSSV rr1-specific RsaI amplified restriction fragment length polymorphism of an amplified 1156-bp fragment thus distinguished the New Jersey blue crab samples from the other WSSV isolates.

Prevalence and significance of hepatitis B virus (HBV) pre-S mutants in serum and liver at different replicative stages of chronic HBV infection

Several types of naturally occurring pre-S mutants in sera or liver tissues in patients with chronic hepatitis B virus (HBV) infection have been identified. To clarify the prevalence and significance of emergence of pre-S mutants, 140 sera and 18 resected livers from patients with HBV were studied. Replicative status was designated as high, intermediate, and low based on the HBV-DNA levels in serum or the expression of HBV antigens in liver. In vitro transfection and Western blot analysis were performed to characterize expression and secretion of HBsAg by the mutant constructs. Five major types (I to V) of pre-S deletion mutants in serum and liver and 2 types (VI and VII) in liver were identified. Pre-S mutant was 6.4% at high replicative phase, 13% at intermediate, and 37.5% at low or nonreplicative phases in serum. In livers, the same tendency existed: pre-S2 deletion mutants emerged and prevailed at a low replicative phase in hepatocytes that expressed a novel marginal pattern of HBsAg and usually clustered in groups. The deletion sequence of pre-S2 region coincides with human leukocyte antigen-restricted T- and B-cell epitopes. In vitro HBsAg was retained in the hepatocytes and synthesis and secretion of major surface antigen decreased for most of the pre-S mutants. Pre-S mutants prevailed with evolution of chronic HBV, probably under immune pressure. Emergence of pre-S mutants may account for the life-long persistence and discrepancy of HBsAg in serum and liver in HBV and may confer growth advantage in view of the clustering proliferation of hepatocytes harboring pre-S2 mutant.

Sonographic septation: a useful prognostic indicator of acute thoracic empyema

The aim of this study was to identify sonographic predictors of patient outcomes or need for surgical intervention of acute thoracic empyema. All patients with a clinical diagnosis of thoracic empyema underwent transthoracic ultrasonographic examination and thoracentesis at admission. According to the presence or absence of septa in sonographic images, the patients were classified into two groups: septated and nonseptated. Sonographic findings were analyzed with respect to duration of hospital stay, chest tube drainage, and treatment efficacy. A total of 163 consecutive patients were included in the study (83 patients with septated and 80 with nonseptated sonographic images). The mean duration of hospital stay (35.4 versus 27.0 days, P = 0.009) and chest tube drainage (13.1 versus 7.6 days, P < 0.001) for the patients with septa were significantly longer than for those without septa. The patients with septa were more likely to undergo intrapleural fibrinolytic therapy (63.8% versus 38.8%, odds ratio 2.79, P = 0.001) and surgical intervention (24.3% versus 7.5%, odds ratio 3.92, P = 0.004). We concluded that sonographic septation is a useful sign to predict the need for subsequent intrapleural fibrinolytic therapy and surgical intervention in cases of acute thoracic empyema. Early fibrinolytic therapy or even surgical intervention may be indicated in patients with sonographic septations.

Interaction of shrimp ras protein with mammalian caveolin-1

BALB/3T3 cells were transformed by transfection with DNA encoding the mutated ras(Q(61)K) from shrimp Penaeus japonicus (Huang and Chuang. 1999. J Exp Zool 283:510-521). The caveolin-1 in the membrane fraction extractable with 2% octyl glucoside was significant reduced, compared to untransformed cells. To understand this in more detail, the interaction of S-Ras with caveolin was investigated using caveolin-1 purified from rat lungs. The purified caveolin-1 binds c-Src, suppressing its autophosphorylation. It also binds to phosphatidylserine-cholesterol liposomes. These reconstituted caveolin-phosphatidylserine-cholesterol vesicles, which act as a model of caveolae, recruit both bacterially expressed S-Ras and rat K(B)-Ras proteins, as demonstrated on western blots with antibodies against caveolin-1 and Ras. Caveolin-1 suppressed the intrinsic GTPase activity of S-Ras, sustaining it in the active GTP bound form. By contrast, caveolin-1 enhanced the intrinsic GTPase activity of K(B)-Ras, to convert it into the inactive GDP-bound form. These events suggest that caveolin may act as a docking site for Ras proteins and may be able to either maintain or alter their activity state. These events may be associated with the ability of S-ras(Q(61)K) to successfully transform cells.