Chemical analysis of the developmental pattern of polysialylation in chicken brain. Expression of only an extended form of polysialyl chains during embryogenesis and the presence of disialyl residues in both embryonic and adult chicken brains

Recent studies have demonstrated the involvement of two polysialyltransferases in neural cell adhesion molecule (N-CAM) polysialylation. The availability of cDNAs encoding these enzymes facilitated studies on polysialylation of N-CAM. However, there is a dearth of detailed structural information on the degree of polymerization (DP), DP ranges, and the influence of embryogenesis on the DP. It is also unclear how many polysialic acid (polySia) chains are attached to a single core N-glycan. In this paper we applied new, efficient, and sensitive high pressure liquid chromatography methods to qualitatively and quantitatively analyze the polySia structures expressed on embryonic and adult chicken brain N-CAM. Our studies resulted in the following new findings. 1) The DP of the polySia chains was invariably 40-50 throughout developmental stages from embryonic day 5 to 21 after fertilization. In contrast, glycopeptides containing polySia with shorter DPs, ranging from 15 to 35, were isolated from adult brain. 2) Chemical evidence showed glycan chains abundant in Neu5Acalpha2,8Neu5Ac were expressed during all developmental stages including adult. 3) Levels of both di- and polySia were found to show distinctive changes during embryonic development.

Choledochal cyst associated with acute acalculous cholecystitis

A 7-year-old girl underwent laparotomy for suspected acute appendicitis. Instead, bile peritonitis with hydrops of gallbladder and normal appendix were noted. Dilatation of the CBD was observed, and choledochal cyst was documented by intraoperative cholangiography. Cholecystectomy and T-tube placement were performed. Postoperative follow-up by ultrasound lasted for 9 months. The CBD remained the same size without clinical manifestation.

Activation of extracellular signal-regulated kinase (ERK) and Akt by human serotonin 5-HT(1B) receptors in transfected BE(2)-C neuroblastoma cells is inhibited by RGS4

Regulator of G protein signaling (RGS) proteins are GTPase-activating proteins for heterotrimeric G proteins. One of the best-studied RGS proteins, RGS4, accelerates the rate of GTP hydrolysis by all G(i) and G(q) alpha subunits yet has been shown to exhibit receptor selectivity. Although RGS4 is expressed primarily in brain, its effect on modulating the activity of serotonergic receptors has not yet been reported. In the present study, transfected BE(2)-C human neuroblastoma cells expressing human 5-HT(1B) receptors were used to demonstrate that RGS4 can inhibit the coupling of 5-HT(1B) receptors to cellular signals. Serotonin and sumatriptan were found to stimulate activation of extracellular signal-regulated kinase. This activation was attenuated, but not completely inhibited, by RGS4. Similar inhibition by RGS4 of the protein kinase Akt was also observed. As RGS4 is expressed at high levels in brain, these results suggest that it may play a role in regulating serotonergic pathways.

CROC-4: a novel brain specific transcriptional activator of c-fos expressed from proliferation through to maturation of multiple neuronal cell types

A novel, brain-specific cDNA, denoted CROC-4, was cloned from human brain by a contingent replication of cDNA procedure capable of detecting transcriptional activators of the human c-fos proto-oncogene promoter. CROC-4 encoded an 18-kDa serine/threonine-rich polypeptide containing a P-loop motif and an SH3-binding region with phosphorylation sites for a variety of protein kinases (cdc2, CDK2, MAPK, CDK5, protein kinase C, Ca(2+)/calmodulin protein kinase 2, casein kinase 2) involved in cell proliferation and differentiation. Immunohistochemistry revealed that during early development, expression was associated with proliferating and migrating cells throughout the rodent brain, initially appearing in the proliferative ventricular zones. During late development and in adult human brain, CROC-4 was expressed in diverse brain regions including the thalamus, subthalamic nucleus, corpus callosum, substantia nigra, caudate nucleus, amygdala, and hippocampus. The association of CROC-4 expression with proliferating regions of developing brain and retention in regions of the adult brain, as well as the punctate nuclear location, suggest that CROC-4 participates in brain-specific c-fos signaling pathways involved in cellular remodeling of brain architecture.

A left atrial thrombus is not an absolute limitation to balloon mitral commissurotomy for patients with mitral stenosis. a serial transesophageal echocardiographic study

Previous reports did not encourage balloon mitral commissurotomy (BMC) when left atrial (LA) thrombi were located beyond LA appendage. We hypothesize that LA thrombi may be resolved in some patients after anticoagulant therapy, and BMC can be performed subsequently. In the present study, we used transesophageal echocardiography (TEE) to evaluate the effects of anticoagulant on LA thrombi in patients with mitral stenosis, to compare the clinical differences between patients with (group A) and without (group B) resolution of LA thrombi, and to evaluate the safety of subsequent BMC in these patients. TEE was performed on 190 consecutive patients with mitral stenosis; 14 (7.4%) of them were found with LA thrombi. Serial TEE was performed and optimal anticoagulant therapy was achieved in all 14 patients. The thrombi were located within the LA appendage in 6 cases, attached to the LA posterior wall in 5, posterior wall and interatrial septum in 1, and LA appendage and posterior wall in 2. Based on the 6-month TEE follow-up, we found that the LA thrombi disappeared in 8 (57.2%) patients (group A) and persisted in 6 patients (group B). LA thrombi resolved within 3 months in 7 group A patients (87.5%). Furthermore, the resolution of LA thrombi was more frequently observed in patients either with a smaller LA dimension (51.9 +/- 3.4 vs. 57.8 +/- 4.8 mm, p = 0.02) or with their thrombi located inside their LA appendage (p = 0.03). No differences in other clinical and echocardiographic variables were noted between these two groups. Subsequently, group A patients underwent BMC without complications of systemic embolization. In conclusion, LA thrombi can be resolved after optimal anticoagulant therapy in a considerable proportion of patients with mitral stenosis. Serial TEE studies are helpful to observe LA thrombus resolution; they may also be useful in planning the treatment strategy.

Decreasing early recurrence rate of acute intussusception by the use of dexamethasone

Premedication with intramuscular dexamethasone may decrease the rate of early recurrent intussusception by amelioration of lymphoid hyperplasia.

Age-associated changes in interferon-gamma and interleukin-4 secretion by purified human CD4+ and CD8+ T cells

Aging is associated with a decline in immune function. Interferon-gamma (IFN-gamma) and interleukin-4 (IL-4), two important immune deviation-related cytokines, are mainly produced by type 1 and type 2 T cells, respectively. To investigate the age-associated changes in the secretion of these two cytokines, 20 elderly and 20 young subjects fulfilling the SENIEUR protocol were enrolled. The ratios of CD4+ to CD8+ T cells were not different between the two age groups. The CD4+ and CD8+ T cells were purified by a magnetic cell sorting system, and then activated by concurrent anti-CD3 and anti-CD28 stimulation. The released cytokines were determined by ELISA. Both the CD4+ and the CD8+ T cells of the elderly individuals secreted a significantly larger amount of IFN-gamma after activation. Profound IL-4 production by CD8+ T cells was observed in the older subjects compared with that of the young subjects. These data suggested that age-associated decrease in immunity may be related to an imbalance in the secretion of immune deviation cytokines. The number of IL-4-secreting CD8+ T cells (T cytotoxic 2) rose significantly in the older individuals. Our design also provided a useful way to differentiate the T cell subsets secreting the same cytokine, such as IFN-gamma-producing T helper 1 and T cytotoxic 1 cells.

Primary antiphospholipid syndrome manifested as venous stasis retinopathy

Primary antiphospholipid syndrome is a condition in which antiphospholipid antibodies may be present without any associated medical disorder. Thrombosis is the hallmark of this syndrome. We report the case of a 22-year-old female with the chief complaint of floating spots in the right eye for two months. No underlying connective tissue disease or systemic disease was noted. Ophthalmic examination revealed retinal hemorrhage, retinal vein engorgement and optic disk swelling in the right eye only, and normal visual acuity in both eyes. Retinal fluorescein angiography showed venous stasis and branch vein leakage in the right eye. An antibody profile revealed the presence of immunoglobulin G anticardiolipin antibodies, which confirmed the diagnosis of primary antiphospholipid syndrome.

In vivo analysis of cancerous gene expression by RNA-polymerase chain reaction

An easy and routine procedure to amplify messenger RNA (mRNA) libraries from a few tissue cells can provide molecular gene expression profiles at high resolution. A novel PCR-like method, the RNA-PCR, was developed to generate high quality and quantity mRNAs from as few as 20 cells (2 pg mRNAs). The principle relies upon the cycling steps of promoter-linked double-stranded cDNA synthesis and promoter-driven transcription to amplify mRNAs up to 250-fold/cycle with good representation of high and low copy mRNAs. The amplified mRNA libraries were shown to possess high fidelity, purity, specificity and reproducibility for in vivo analyses of cancerous gene expression in human prostate cancers.

[Changes and its measurement of intracellular Ca2+ during exposure to hyperbaric oxygen]

Objective. To investigate the rule of change of intracellular Ca2+ and its measurement method during exposure to hyperbaric oxygen (HBO). Method. Microfluorescence method was used to measure the changes of intracellular Ca2+ concentration in co-cultured endothelial cells (EC) and smooth muscle cells (SMC) in a specially designed miniature oxygen chamber. Result. (1) [Ca2+]i changes during HBO exposure can be clearly observed directly in the chamber. (2) Within 5 min during 0.2 MPa and 0.3 MPa HBO exposure, EC[Ca2+]i and SMC[Ca2+]i showed a tendency, to increase at first and then decrease with time throughout the exposures, especially the SMC[Ca2+]i. The EC ruptured under exposure to 0.4 MPa HBO. Conclusion. During HBO exposure, EC[Ca2+]i and SMC[Ca2+]i showed biphasic changes, which increased at first and then decreased. The technique and method used were reliable and suitable for investigating of intracellular [Ca2+]i changes under HBO.

Multiplane transesophageal echocardiography for assessing cardiac abnormalities: comparison to biplane imaging

BACKGROUND

Transesophageal echocardiography (TEE) is useful for visualizing the spatial relationships of the cardiac anatomy. The purpose of this study was to compare the diagnostic yield of multiplane TEE with that of biplane TEE in assessing cardiac abnormalities.

METHODS

A total of 102 consecutive patients underwent an initial comprehensive diagnostic assessment using transverse (0 degree) and longitudinal (90 degrees +/- 2 degrees) planes in the biplane imaging technique. "Off-axis" tomographic sections through the full 0 degree to 180 degrees angle were obtained later by means of the gradual electrical rotation of the transducer. The echoscope can be manipulated to improve the quality of images. All data were recorded on high fidelity videotapes. Subsequently, one observer reviewed only biplane TEE images, while another reviewed only multiplane TEE images; both were blinded to the other's TEE data. The echocardiographic results obtained by these two observers were compared to determine whether multiplane TEE provides any additional information.

RESULTS

Multiplane TEE detected more cardiac lesions (275) compared to biplane TEE (235). Significantly more (70 cases) information affecting patient management was obtained using multiplane TEE. Among these patients, biplane TEE detected cardiac lesions in 48 (68.6%) patients. Additional diagnoses provided by multiplane TEE were found in 22 (31.4%) patients. These findings included ventricular septal defect in two patients, prosthetic valve dysfunction in three, cardiac tumor or clot in four, endocarditis in two, aortic dissection in one, valvular abnormality in nine and coronary arteriovenous fistula in one.

CONCLUSIONS

Multiplane TEE provides precise visualization of cardiac structures without undue probe manipulation, resulting in greater diagnostic assurance than does biplane TEE.

Evaluation of high-performance anion-exchange chromatography with pulsed electrochemical and fluorometric detection for extensive application to the analysisof homologous series of oligo- and polysialic acids in bioactive molecules

Our previous studies have shown extensively diverse structures in oligo/polymers of sialic acid (oligo/polySia) that are expressed often in developmentally regulated manner on animal glycoconjugates. The aim of this study was to establish highlysensitive and specific methods that can be used to identify diverse types of oligo/polySia and thus can be applied to studies of biological phenomena associated with the differential expression of oligo/polySia chains with different degree of polymerization (DP). As model compounds, we analyzed five different homologous series of oligo/polySia, (-->8Neu5Acalpha2-->)(n), (-->9Neu 5Acalpha2-->)(n), (-->8Neu5Gcalpha2-->)(n), (-->5-O(glycolyl)-Neu5Gcalpha2-->)(n), and Neu5Gc9SO(4)alpha2-->(-->5-O(glycolyl)-Neu5Gcalpha2--> )(n), ()expressed in various biopolymers. The latter two structures have recently been identified in sea urchin egg receptor for sperm. First we examined application of high-performance anion-exchange chromatography (HPAEC) on a CarboPac PA-100 column with pulsed electrochemical detection (PED) to new types of oligo/polySiacompounds and confirmed that resolution of high polymers (DP >70) of sialic acids was remarkable as reported previously. However, there are limitations in sensitivity and selectivity in PED that become significant when material is available only in a minute amount or material contained a large proportion of protein. These limitations can be circumvented by fluorometric detection of oligo/polySia tagged with 1,2-diamino-4, 5-methyl-enedioxybenzene (DMB) at the reducing terminal residues after separation on a MonoQ HR5/5 column. The latter method can be applied to any type of oligo/polySia we examined if we choose the derivatization conditions and is more sensitive and specific than the method with PED for analysis of oligo/polySia with DP up to 25.

Circadian and weekly variations in pain onset of acute myocardial infarction

BACKGROUND

A seasonal variation with more myocardial infarctions in the winter months due to cold weather has been reported. Other reports have described excess numbers of acute myocardial infarction (AMI) in the summer in Southern USA due to hot temperatures. To determine whether circadian and seasonal variations affect the incidence of AMI in the subtropical area of Taiwan, 480 consecutive patients with AMI admitted to our coronary care units were analyzed.

METHODS

Six-hourly intervals over 24 hours (4 periods), daily intervals in a week (7 days) and monthly intervals in a year (12 months) were respectively studied. The distributions of the numbers of AMI occurring in the six-hour intervals were tested for differences among the four periods using the chi-squared test for goodness of fit.

RESULTS

We found that there was a circadian variation in the onset of AMI with a morning peak (6 am to noon) (35%, chi 2 = 28.52, df = 3, p < 0.01) but no secondary late evening peak. The incidence of AMI was significantly lower on Sundays (9%) than on the other weekdays (chi 2 = 16.37, df = 6, p = 0.012). However, no seasonal variation (no winter or summer peaks) occurred in the incidence of AMI in this study (chi 2 = 0.77, df = 3, p = 0.99).

CONCLUSION

Our results showed that there was a predominant morning peak in the onset of AMI. The low incidence of AMI cases on Sunday compared with other weekdays suggested that relief from tension or workload on Sundays might have an important role in this low percentage of AMI. Differing from other reports, there was no seasonal variation in the occurrence of AMI in our study, suggesting that the warm climate of a subtropical region does not provide an environment that is likely to increase the frequency of AMI.

Intussusception in a child infected with enterovirus: case report

Most intussusceptions in childhood are idiopathic. The association of viral infection has been suspected for decades. We report a case of ileocolonic intussusception in a child during a course of enterovirus infection. A 20-month-old girl with vomiting and irritable crying of 4 days' duration was found to have intussusception by sonography. She had suffered from herpangina one week earlier. Due to her peritoneal signs, she underwent surgical manual reduction. A cluster of enlarged lymph nodes in the intussuscipiens was noted preoperatively by high resolution ultrasound. Two swollen lymph nodes were removed for pathologic evaluation and examined for a viral genome by polymerase chain reaction (PCR) amplification. Panenterovirus base pairs were confirmed on the electrophoresis print. During postoperative sonographic follow-up, significant shrinkage of previous mesenteric lymphoid hyperplasia was observed. In this article, we present the first case of childhood intussusception in associated with enterovirus infection, in which the panenterovirus genome was identified in the patient's mesenteric lymph nodes. This was also the first evaluation of the role of mesenteric lymph nodes in intussusception by high resolution sonography.

Congenital hepatic arterioportal fistula complicated with gastrointestinal bleeding treated with transcatheter embolization: case report

Congenital hepatic arterioportal fistula (HAVF) is extremely rare in children. We present a patient with congenital hepaticoportal arteriovenous fistula complicated with gastrointestinal bleeding treated using transcatheter arterial embolization. Our patient was the youngest (2 days old) case ever reported with congenital HAVF and the first one to receive arterial embolization for HAVF during childhood. The 3-year-old girl was suggested of having congenital HAVF using Doppler ultrasonography. However, her family refused further investigation, and she was lost to follow-up. Three years later, she was sent to our hospital due to melaena. Repeated ultrasonography revealed dilated intrahepatic portal vein with arterial flow demonstrated using Doppler imaging. No esophageal varices or gastric or duodenal ulcer was seen during endoscopy. Angiography showed a HAVF and transcatheter embolization was done simultaneously. Follow-up at one and two weeks post-embolization revealed no more shunt flow within the portal vein, though cystic like dilatation of the portal vein persisted, and no thrombosis was observed. This case emphasizes that transcatheter arterial embolization can be easily and successfully used for treating childhood congenital HAVF. Abnormal dilatation of the portal vein in children needs doppler evaluation and possibly angiography.

Optimal control of blood pressure can reverse left ventricular hypertrophy in uremic hypertensive hemodialysis patients

We investigated the effects of antihypertensive treatment on left ventricular hypertrophy (LVH) of long-term hemodialysis patients. In uremic patients, it is still controversial in antihypertensive effect to the regression of LVH. The left ventricular size and function of 39 uremic hypertensive long-term hemodialysis patients (27 men, 12 women, mean age 58.3) was evaluated with M-mode, 2-dimensional and Doppler echocardiography before, and 12 months after, the start of combined antihypertensive therapy. This therapy included angiotensin II converting enzyme inhibitors, beta-blockers and calcium antagonists. Patients were classified as responders or nonresponders, depending upon whether their systolic blood pressure (SBP) decreased by more than 10 mmHg after antihypertensive treatment for 12 months. Before treatment, 36 (92%) patients had LVH and diastolic dysfunction and three (8%) had systolic dysfunction. At the end of 12 months, only 25 (64%) patients had LVH, 30 (77%) had diastolic dysfunction and 2 (5%) had systolic dysfunction. Left ventricular mass index (LVMI) also decreased from 203.63 +/- 70.47 g/m2 to 178.57 +/- 67.31 g/m2. LVMI correlated with systolic blood pressure (SBP) but did not correlate with diastolic blood pressure (DBP). There were 26 responders and 13 non-responders. Among responders, both the SBP (153.91 +/- 13.24 mmHg vs 134.43 +/- 14.21 mmHg, p < 0.01) and DBP (90.39 +/- 7.89 mmHg vs 79.98 +/- 7.35 mmHg, p < 0.01) decreased significantly after antihypertensive therapy. Responders also exhibited progressive regression of LVH (LVMI decreased significantly from 208.52 +/- 72.03 g/m2 to 168.52 +/- 55.53 g/m2, p < 0.05). However, LVH regression was not found in nonresponders (LVMI showed 194.84 +/- 64.36 g/m2 vs 193.66 +/- 77.67 g/m2). We conclude that good control of blood pressure can reverse LVH in hypertensive hemodialysis patients.

Lipid A mutant Salmonella with suppressed virulence and TNFalpha induction retain tumor-targeting in vivo

Systemically administered tumor-targeted Salmonella has been developed as an anticancer agent, although its use could be limited by the potential induction of tumor necrosis factor alpha (TNFalpha)-mediated septic shock stimulated by lipid A. Genetic modifications of tumor-targeting Salmonella that alter lipid A and increase safety must, however, retain the useful properties of this bacteria. We report here that disruption of the Salmonella msbB gene reduces TNFalpha induction and increases the LD50 of this pathogenic bacteria by 10,000-fold. Notwithstanding this enormous difference, Salmonella retains its tumor-targeting properties, exhibiting tumor accumulation ratios in excess of 1000:1 compared with normal tissues. Administration of this bacteria to mice bearing melanoma results in tumors that are less than 6% the size of tumors in untreated controls at day 18. Thus, the antitumor activity previously demonstrated using tumor-targeting Salmonella with normal lipid A is retained. Lipid modification of tumor-specific bacterial vectors provides a means for reducing septic shock and further suggests that the antitumor activity of these bacteria may be independent of TNFalpha.

Identification of free deaminated sialic acid (2-keto-3-deoxy-D-glycero-D-galacto-nononic acid) in human red blood cells and its elevated expression in fetal cord red blood cells and ovarian cancer cells

Chemical studies have shown the occurrence of the deaminated sialic acid 2-keto-3-deoxy-D-glycero-D-galacto-nononic acid (KDN) in paired samples of blood obtained from mothers and newborns of healthy human individuals. Most of the KDN was found in red blood cells, although low levels were detected in mononuclear cells. No N-glycolylneuraminic acid was detected. Unexpectedly, nearly all of the KDN in fetal cord and matched maternal red blood cells was present as the free sugar and comparatively little occurred conjugated or as cytidine 5'-KDN phosphate. The amount of free KDN in fetal newborn red blood cells was 2.4-fold higher than in red blood cells from the mothers or from healthy nonpregnant women. Free KDN was also identified in normal human ovaries, in ovarian tumors, and in ascites cells obtained from ovarian cancer patients. Importantly, as in fetal cord red blood cells, a distinguishing feature of KDN expression in ovarian tumor cells was an elevated level of free KDN compared with normal controls. A positive correlation was found between an increase in the ratio of free KDN/N-acetylneuraminic acid in ovarian adenocarcinomas and the stage of malignancy. This was particularly evident in tumor cells isolated from the ascites fluid. The central importance of these new findings is 2-fold. First, they show that free KDN is a minor but ubiquitous sialic acid in human red blood cells and that its elevated expression in red blood cells from fetal cord blood compared with maternal red blood cells may be developmentally related to blood cell formation during embryogenesis. Second, the enhanced expression of KDN in ovarian cancer cells suggests that this sialic acid, like the alpha2,8-linked polysialic acid glycotope, may be an oncofetal antigen in these tumors and thus could be an "early warning" signal for onset of disease and/or a marker for detection of recurrence of disease. These new findings highlight the importance of elucidating the role that KDN and KDN-containing glycoconjugates may play in normal development and malignancy.

Up-regulation of CIR1/CROC1 expression upon cell immortalization and in tumor-derived human cell lines

Acquisition of the immortal phenotype by tumor cells represents an essential and potentially rate-limiting step in tumorigenesis. To identify changes in gene expression that are associated with the early stages of cell immortalization, we compared genetically matched pairs of pre-immortal and immortal human cell clones by mRNA differential display. Two transcripts, denoted CIR1 and CIR2, were identified which were up-regulated in immortal cells. Sequence analysis revealed CIR1 to be identical to the recently cloned CROC1/UEV-1 gene, whereas CIR2 corresponds to an as yet uncharacterized 1.2 kb mRNA. A 5-6-fold elevation in CIR1/CROC1 expression and a 2-3-fold elevation in CIR2 expression were observed in SV40-transformed human embryonic kidney cells immediately following proliferative crisis, suggesting a potential role for these genes in immortalization. Expression of CIR1/CROC1 was found to be elevated also in a variety of immortal human tumor-derived cell lines, as compared to their normal tissue counterparts. These results are compatible with induction of CIR1/CROC1 being an early event in the acquisition of immortality and with a role for this gene in the immortal phenotype of tumor cells.

The products of the yeast MMS2 and two human homologs (hMMS2 and CROC-1) define a structurally and functionally conserved Ubc-like protein family

Eukaryotic genes encoding ubiquitin-congugating enzyme (Ubc)-like proteins have been isolated from both human and yeast cells. The CROC-1 gene was isolated by its ability to transactivate c- fos expression in cell culture through a tandem repeat enhancer sequence. The yeast MMS2 gene was cloned by its ability to complement the methyl methanesulfonate sensitivity of the mms2-1 mutant and was later shown to be involved in DNA post-replication repair. We report here the identification of a human MMS2 ( hMMS2 ) cDNA encoding a novel human Ubc-like protein. hMMS2 and CROC-1 share >90% amino acid sequence identity, but their DNA probes hybridize to distinct transcripts. hMMS2 and CROC-1 also share approximately 50% identity and 75% similarity with the entire length of yeast Mms2. Unlike CROC-1 , whose transcript appears to be elevated in all tumor cell lines examined, the hMMS2 transcript is only elevated in some tumor cell lines. Collectively, these results indicate that eukaryotic cells may contain a highly conserved family of Ubc-like proteins that play roles in diverse cellular processes, ranging from DNA repair to signal transduction and cell differentiation. The hMMS2 and CROC-1 genes are able to functionally complement the yeast mms2 defects with regard to sensitivity to DNA damaging agents and spontaneous mutagenesis. Conversely, both MMS2 and hMMS2 were able to transactivate a c- fos - CAT reporter gene in Rat-1 cells in a transient co-transfection assay. We propose that either these proteins function in a common cellular process, such as DNA repair, or they exert their diverse biological roles through a similar biochemical interaction relative to ubiquitination.

High-performance capillary electrophoretic characterization of different types of oligo- and polysialic acid chains

We have carried out comparative structural analysis of novel oligo- and polysialic acid chains from diverse sources. Controlled acid hydrolysates of (a) colominic acid, alpha2-->8-linked homopolymer of N-acetylneuraminic acid (Neu5Ac), (b) alpha2-->8-linked oligo/polyNeu5Gc chains present in rainbow trout egg polysialoglycoprotein, and (c) alpha2-->8-linked oligomers of deaminoneuraminic acid (KDN) residues of KDN-rich glycoprotein derived from rainbow trout vitelline envelope were analyzed by high-performance capillary electrophoresis (HPCE). The results showed that three different types of alpha2-->8-linked oligosialic acids having same degree of polymerization can be separated by HPCE. A partial hydrolysate of colominic acid with mild acid was shown by CE to form intramolecular esters during the controlled hydrolysis and the subsequent workup procedure. In contrast, lactonization of (-->5-Oglycolyl-Neu5Gcalpha2-->)n, alpha2-->5-Oglycolyl-linked homopolymer of N-glycolylneuraminic acid (Neu5Gc) present in the egg jelly coat of sea urchin, did not take place as readily as in (-->8Neu5Acalpha2-->)n.

Churg-Strauss syndrome presenting with pulmonary capillaritis and diffuse alveolar hemorrhage

Churg-Strauss syndrome (CSS) is a rare disorder characterized by the histopathological triad of systemic necrotizing vasculitis, extravascular granuloma, and eosinophilic infiltrate, occurring in individuals with asthma or a history of allergy. We report a case of CSS with rare presentation of diffuse pulmonary hemorrhage. A transbronchial lung biopsy showed necrotizing vasculitis, pulmonary capillaritis, and prominent eosinophilic infiltrate. At autopsy, necrotizing granuloma and diffuse alveolar hemorrhage were found in the lungs. Laboratory data showed hypereosinophilia, disseminated intravascular coagulopathy, and positive anti-proteinase 3 antineutrophil cytoplasmic antibody (ANCA). This case emphasize that CSS should be considered in the differential diagnosis of ANCA-positive vasculitis with diffuse alveolar hemorrhage.

Electrostatics, allostery, and activity of the yeast chorismate mutase

The predicted active site of chorismate mutase of baker's yeast Saccharomyces cerevisiae has been studied by continuum electrostatics, molecular surface/volume calculations, and molecular modeling. Our study shows that despite being subject to an allosteric transition, the enzyme's active-site pocket neither decreased in volume nor deformed significantly in shape between the active R state and the inactive T state. We find that the polar atmosphere in the pocket is responsible for the enzyme's affinity. A single amino acid, Glu23, can adequately account for the atmospheric variation. This residue swings into the active-site pocket from the R state to the T state. In the R state, Glu23 on helix H2 doubly pairs with Arg204 and Lys208 of H11, which is packed against H2. In the T state, a slide occurs between H11 and H2 such that Glu23 can no longer interact with Lys208 and competes with Asp24 for interacting with Arg204. Consequently, Glu23 is found in the T state to couple with Arg157, an active-site residue critical to substrate binding. The tandem sliding of H11 in both monomers profoundly changes the interactions in the dimer interface. The loop between H11 and H12 demonstrates the largest conformational change. Hence, we establish a connection between the allosteric transition and the activity of the enzyme. The conformational change in the transition is suggested to propagate into the active-site pocket via a series of polar interactions that result in polarity reversal in the active-site pocket, which regulates the enzyme's activity.

Absence of a seasonal variation in myocardial infarction onset in a region without temperature extremes

To evaluate whether the incidence of acute myocardial infarction (AMI) attack would have circadian, weekly and monthly variations in a subtropical area, 540 consecutive patients with AMI who were admitted to our coronary care units were analyzed. Six-hour intervals over 24 h, daily intervals in a week (7 days) and monthly intervals in a year (12 months) were studied, respectively. Results showed that there was a circadian variation in the onset of AMI with a morning (6 a.m. to noon) peak (34%, p < 0.01) but no secondary late evening (18-24 p.m.) peak. The incidence of AMI was significantly lower on Sundays (9%) than on the other weekdays (Monday through Saturday; p < 0.05). However, no monthly and seasonal variations in the incidence of AMI (no winter or summer peaks) were observed in this series. This study demonstrated a circadian variation in the onset of AMI attack with a predominant morning peak. The fewer AMI cases on Sundays compared to the other weekdays suggested that freedom from 'stress' or 'work-load' on Sundays might have an important impact on this low incidence of AMI. Unlike the large ranges in cold or hot weather found in temperate regions, the warm climate of a subtropical region does not affect the frequency of AMI.

Primary intracranial leiomyoma: case report

We present a case of intracranial parenchymal leiomyoma in a 20-year-old woman with a chief complaint of numbness and a painful sensation over the right limbs for several years. CT and MRI revealed an intensely enhancing calcified mass. The patient was well, without recurrence, 2 years after surgery.

Molecular shape comparisons in searches for active sites and functional similarity

Here we examine the reliability of surface comparisons in searches for active sites in proteins. Detection of a patch of surface on one protein which is similar to an active site in another, may suggest similarities in enzymatic mechanisms, in enzyme functions and implicate a potential target for ligand/inhibitor design. Specifically, we compare the efficacy of molecular surface comparisons with comparisons of surface atoms and of C(alpha) backbone atoms. We further investigate comparisons of specific atoms, belonging to a predefined pattern of catalytic residues versus comparisons of molecular surfaces and, separately, of surface atoms. This aspect is particularly relevant, as catalytic residues may be (partially) buried. We also explore active site comparisons versus comparisons in which the entire molecular surfaces are scanned. While here we focus on the geometrical aspect of the problem, we also investigate the effect of adding residue labels in these comparisons. Our extensive studies cover the serine proteases, containing the highly conserved triad motif, and the chorismate mutases. Since such active site comparisons entail comparisons between unconnected points in 3D space, an order-independent comparison technique is necessary. The geometric hashing algorithm is ideally suited to handling such a task. It can perform both global shape matching for the whole surfaces of large protein molecules and searching for local shape similarities for small surface motifs. Our results show that molecular surface comparisons work best when the similarity is high. As the similarity deteriorates, the number of potential solutions increases rapidly, making their ranking difficult, particularly when scanning entire molecular surfaces. Utilizing atomic coordinates directly appears more adequate under such circumstances.

Spindle cell carcinoma of the lung: a clinicopathologic presentation of three cases

Three patients with spindle cell carcinoma located in the lower respiratory tract are presented, including cases of two monophasic and one biphasic tumor. On light microscopic examination, the spindle cell components of the tumors were histologically characterized by sheets of fusiform spindle cells that closely resembled a sarcoma. Keratin expression in the spindle cell components of these tumors, as shown by anti-cytokeratin antibody staining, demonstrated their epithelial nature. It is supposed that the spindle cell component displays a spectrum of phenotypes originating from epithelial cells with varying degrees of mesenchymal transformation. It is difficult to establish a diagnosis of this rare primary pulmonary malignancy prior to surgical intervention. A review of the literature allowed for a summary of the clinicopathologic characteristics of this tumor.

Role of UEV-1, an inactive variant of the E2 ubiquitin-conjugating enzymes, in in vitro differentiation and cell cycle behavior of HT-29-M6 intestinal mucosecretory cells

By means of differential RNA display, we have isolated a cDNA corresponding to transcripts that are down-regulated upon differentiation of the goblet cell-like HT-29-M6 human colon carcinoma cell line. These transcripts encode proteins originally identified as CROC-1 on the basis of their capacity to activate transcription of c-fos. We show that these proteins are similar in sequence, and in predicted secondary and tertiary structure, to the ubiquitin-conjugating enzymes, also known as E2. Despite the similarities, these proteins lack a critical cysteine residue essential for the catalytic activity of E2 enzymes and, in vitro, they do not conjugate or transfer ubiquitin to protein substrates. These proteins constitute a distinct subfamily within the E2 protein family and are highly conserved in phylogeny from yeasts to mammals. Therefore, we have designated them UEV (ubiquitin-conjugating E2 enzyme variant) proteins, defined as proteins similar in sequence and structure to the E2 ubiquitin-conjugating enzymes but lacking their enzymatic activity (HW/GDB-approved gene symbol, UBE2V). At least two human genes code for UEV proteins, and one of them, located on chromosome 20q13.2, is expressed as at least four isoforms, generated by alternative splicing. All human cell types analyzed expressed at least one of these isoforms. Constitutive expression of exogenous human UEV in HT-29-M6 cells inhibited their capacity to differentiate upon confluence and caused both the entry of a larger proportion of cells in the division cycle and an accumulation in G2-M. This was accompanied with a profound inhibition of the mitotic kinase, cdk1. These results suggest that UEV proteins are involved in the control of differentiation and could exert their effects by altering cell cycle distribution.

Identification of novel farnesyl protein transferase inhibitors using three-dimensional database searching methods

Generation of a three-dimensional pharmacophore model (hypothesis) that correlates the biological activity of a series of farnesyl protein transferase (FPT) inhibitors, exemplified by the prototype 1-(4-pyridylacetyl)- 4-(8-chloro-5,6-dihydro-11H-benzo [5,6]cyclohepta[1,2-b]pyridin-11-ylidene)piperidine, Sch 44342, 1, with their chemical structure was accomplished using the three-dimensional quantitative structure-activity relationship (3D-QSAR) software program, Catalyst. On the basis of the in vitro FPT inhibitory activity of a training set of compounds, a five-feature hypothesis containing four hydrophobic and one hydrogen bond acceptor region was generated. Using this hypothesis as a three-dimensional query to search our corporate database identified 718 compounds (hits). Determination of the in vitro FPT inhibitory activity using available compounds from this "hitlist" identified five compounds, representing three structurally novel classes, that exhibited in vitro FPT inhibitory activity, IC50 < or = 5 microM. From these three classes, a series of substituted dihydrobenzothiophenes was selected for further structure-FPT inhibitory activity relationship studies. The results from these studies is discussed.

Incidence of NIDDM and the effects of gender, obesity and hyperinsulinaemia in Taiwan

Our aim is to determine non-insulin-dependent diabetes mellitus (NIDDM) incidence in Taiwan and examine its relation to obesity and hyperinsulinaemia in Chinese men and women. A total of 995 men and 1195 women aged 35-74 years free from diabetes in two townships in Taiwan were followed up with a second examination. At baseline general and metabolic data were recorded, and detailed anthropometric parameters and plasma glucose and insulin were assessed. World Health Organisation (WHO) criteria of fasting glucose 7.8 mmol/l or greater was utilized for defining diabetes. The age-standardized incidence rate based on the United States population in 1970 was 9.3/1000 (CI 5.8-12.8) in men and 9.3/1000 (CI 6.2-12.4) in women and the based on the WHO population in 1976 was 8.9/1000 (CI .5-12.3) in men and 8.9/1000 (CI 5.9-11.9) in women for the Chinese who had a mean BMI slightly greater than 24 (kg/m2). The predictability of the plasma glucose level was greater than that of the insulin level and the obesity indices. NIDDM incidence increased approximately threefold with each 0.67 mmol/l increase in plasma glucose level in men and women. The present study demonstrated the essential relationship of not only BMI but also central obesity indices (such as subscapular and waist circumference) to the incidence of NIDDM among men and women and a stronger relationship between NIDDM incidence and obesity in women than in men. The predictive effects of obesity indices and fasting plasma insulin values on NIDDM risk were independent of each other in men. Obesity and hyperinsulinaemia each without the presence of the other can lead to an increased risk of NIDDM. In women the NIDDM incidence increased more than additively in those with both obesity and hyperinsulinaemia compared to those with single obesity or hyperinsulinaemia. A slightly higher incidence of NIDDM in Taiwan than in western countries was found. The importance of obesity is indicated for predicting NIDDM in the community. Hyperinsulinaemia was found to play a significant role in predicting NIDDM incidence independent of obesity in men and synergistically with obesity in women.

Minimally-invasive early prenatal diagnosis using fluorescence in situ hybridization on samples from uterine lavage

A two-phase study was undertaken to examine the efficiency of using transcervical cells (TCCs) collected by uterine lavage and fluorescence in situ hybridization (FISH) for early prenatal diagnosis of fetal chromosome aneuploidy. Uterine lavage was performed in 50 women scheduled for elective termination of pregnancy (TOP, n = 35) or chorionic villus sampling (CVS, n = 15) between 6 and 11 weeks of gestation. TCCS were dissociated by trypsin and collagenase, and interphase FISH was carried out for chromosomes X, Y, 13/21, and 18. The phase I study comprised 36 women. The FISH results were compared with the cytogenetic analysis from long-term culture of villus samples collected at TOP or CVS. Among the 36 samples, 15 had a normal male karyotype and 21 had a normal female karyotype. FISH on TCCs correctly identified 13 out of the 15 pregnancies with a male fetus. In phase II, uterine lavage was performed on 14 women. The samples were first tested for the presence of trophoblasts with an anti-trophoblast antibody, GB25, by immunohistochemical staining. Among 12 GB25-positive samples, the FISH results corresponded to the fetal karyotype. One of the GB25-positive samples had five signals for the chromosome 13/21 probe. The cytogenetic analysis confirmed that the fetus had a karyotype of 47, XX, +21. In the GB25-negative samples, FISH failed to identify one male pregnancy. Follow-up was carried out on 13 ongoing pregnancies and no maternal or fetal complications were discovered. This study demonstrates that fetal chromosome numeration can be carried out using FISH on uterine lavage samples in early pregnancy. However, a specific fetal cell marker, such as specific anti-trophoblast antibody, is necessary to avoid a false-negative result.

Predicting the outcome of hemodialysis arteriovenous fistulae using duplex ultrasonography

Duplex ultrasonography is a reliable method for assessing the anatomic features and blood flow rate of a vascular access point of hemodialysis. We assessed the value of measurement of cross-sectional area and blood flow rate of the major outflow veins using duplex ultrasonography in predicting the outcome of fistulae. Radiocephalic arteriovenous fistulae were created in 126 consecutive end-stage renal failure patients (55 men, 71 women; aged 20-83 yr) and examined using duplex ultrasonography in the second week following surgery. Examinations were repeated in 45 of the 126 fistulae in the third week. The outcome of new fistulae was classified as success or failure. The failure group fistulae were further classified as delayed maturation or primary failure. The cross-sectional area (12.1 +/- 3.5 vs 6.9 +/- 2.4 mm2) and blood flow rate (825.6 +/- 424.3 vs 303.7 +/- 114.5 mL/min) were significantly lower in the failure group, but there was no difference between the subgroups of primary failure and delayed maturation. Receiver-operating characteristic plots were generated for cross-sectional area and blood flow rate. The best cut-off point for distinguishing successful outcome from failure was 8.5 mm2 for cross-sectional area (sensitivity 0.823, specificity 0.867, positive predictive value 0.952, negative predictive value 0.605) and 425 mL/min for blood flow rate (sensitivity 0.813, specificity 0.933, positive predictive value 0.975, negative predictive value 0.609). Our findings show the cross-sectional area and blood flow rate, as measured using duplex ultrasonography, are useful in predicting the outcome of vascular access points of hemodialysis.

Reference spirometric values in healthy Chinese neversmokers in two townships of Taiwan

The present community-based study was performed to provide predictive equations and lower boundaries of normal values for forced expiratory volume in one second (FEVI), forced vital capacity (FVC), and their percent ratio (FEV1%) in non-smoking, healthy adult men and women residing in communities, using ATS-recommended techniques and equipment. Use was made of data collected cross-sectionally from Nov. 1990 to Dec. 1993 in an ongoing longitudinal study on evolution of cardiovascular disease risk factors in Chinese. The spirometric values in our population reached their peak at around age 20. After age 20, a downward age trend was observed for FVC, FEV1, and FEV1%. Linear and negative relations were found in adults for each of the three spirometric values with age. Linear and positive relations were found between height and FVC or FEV1, but not between height and FEV1%. The age trends of FVC and FEV1 in Chinese adults were similar to those in Caucasians. Mean FVC and FEV1 levels of Chinese in Taiwan were systematically lower than those of Caucasians for a given height and a given age. Age and height specific percentile values of FVC and FEV1 and the age-specific percentile value of FEV1% are provided for adult men and women in this community study.

Investigation of the enzymatic mechanism of the yeast chorismate mutase by docking a transition state analog

The structure of the complex of the chorismate mutase from the yeast Saccharomyces cerevisiae with a transition state analog is constructed using a suite of docking tools. The construction finds the best location for the active site in the enzyme, and the best orientation of the analog compound in the active site. The resulting complex shows extensive salt links and hydrogen bonds between the enzyme and the compound, including those mediated by water molecules. A network of polar interactions between amino acid residues is found to solidify the active site of the enzyme. The enzymatic mechanism suggested for a bacterial chorismate mutase, that the active site is by design capable of selecting an active conformer of the substrate, and of stabilizing the transition state, is apparently intact in the yeast enzyme. No direct evidence is found to support an alternative mechanism which involves specific catalytic groups, although the possibility is not eliminated. This finding reinforces the notion of a function being evolutionarily conserved via a common mechanism, rather than via sequential or structural homology.

Salmonella typhimurium brain abscess in a six-month-old infant: a case report and review of the literature

We report the case of a six-month-old male infant with brain abscess caused by Salmonella typhimurium. Upon admission, he was suffering from fever, diarrhea, drowsiness and convulsion. Salmonella meningitis was identified by CSF examination. Following failure of antibiotic therapy to control his fever, brain computerized tomography (CT) was ordered 5 days later and revealed a brain abscess. He received surgical excision of the abscess and recovered completely after receiving ceftriaxone therapy for 8 weeks. The case of our patient, together with 11 cases of Salmonella brain abscess from the English literature are reviewed. There was a male preponderance among these patients (male: female = 2.67 : 1) and the majority were less than one year old. Salmonella typhimurium, typhi, and enteritidis occurred most frequently. Fever, seizure, signs and symptoms of increased intracranial pressure and change in mental status were the most common clinical features. Purulent meningitis was a major predisposing factor. Successful treatment was associated with early identification, prompt surgical intervention, high dose, long-term antibiotic therapy, and close follow-up for possible recurrence and to determine the presence of neurological sequelae.

CROC-1 encodes a protein which mediates transcriptional activation of the human FOS promoter

The cloning of signal transducing molecules capable of activating the human FOS proto-oncogene promoter was achieved by co-transfecting a modified human FOS promoter-driven polyomavirus large T antigen gene (P(f)LAG-8) with a human brain cDNA library, incorporated into a replication-competent mammalian retroviral expression vector whose replication occurs in the presence of T antigen. In murine cells, transcriptional activation of the P(f)LAG-8 promoter by a biologically active, cDNA-encoded signalling molecule resulted in plasmid replication. Replicated plasmids, following selective cleavage of unreplicated plasmids by Dpn1, were recovered by transformation into competent bacteria. Successive P(f)LAG-8/cDNA library co-transfections, using library plasmids resulting from prior transfections, ultimately resulted in the identification of individual plasmids capable of transcriptionally activating the FOS promoter. DNA sequencing revealed the first plasmid, denoted CROC-1, to contain a 1.8-kb cDNA encoding a 16.5-kDa nuclear protein possessing a bipartite structure comprised an amino-terminal acidic domain and a carboxy-terminal basic domain, and displaying partial homology to the HMG domain of the TAF(II)250 transcription cofactor. Co-transfection of CROC-1 with various FOS/CAT reporter genes revealed that the human FOS promoter region spanning -56 to - 105, encompassing two identical 8-bp DR enhancer sequences, was necessary for CROC-1-mediated transcriptional activation. Results suggest that CROC-1 participates in intracellular signalling pathways involved in induction of the human FOS promoter.

The relation between thickened aortic valve and coronary artery disease

BACKGROUND

The relationship between the site of aortic valve thickening and ipsilateral coronary artery stenosis has not been reported previously. This study was undertaken to test the hypothesis that left-sided coronary cusp thickening may be associated with a left-sided coronary artery stenosis, and also as would be in the right-sided relationship.

METHODS

Two-dimensional echocardiography and cardiac catheterization were used to evaluate 420 consecutive patients. One hundred and six patients who had echocardiographic evidence of a single aortic valve thickening were studied to determine whether there was a relation between the coronary artery stenosis and the aortic valve thickening at the same side. Thickened aortic valve was defined as an aortic valve thickness to aortic wall thickness ratio > or = 1.0. Coronary artery disease (CAD) was defined as a > 50% luminal diameter narrowing of the left main coronary artery or a > 70% luminal diameter narrowing of the coronary artery other than the left main coronary artery.

RESULTS

Patients with a thickened aortic valve had a greater incidence of CAD (89/132, 67.4%) than those without (141/288, 49.0%) (p < 0.05). In patients with thickened aortic valves, the incidence of CAD was 45.5% in the fifth decade, 60% in the sixth decade, 69.6% in the seventh decade and 74.1% in the eighth decade. Progressive increase of the incidence of CAD was not found in patients without a thickened aortic valve. In the 106 cases with a single aortic valve thickening, 30 patients (28.3%) had a left coronary cusp thickening; 12 of them (40%) had a left-sided coronary artery stenosis, 3 patients (10%) had right coronary artery stenosis and 7 patients (23.3%) had no coronary artery stenosis. In the 34 patients with right coronary cusp thickening, the stenosis occurred at the left coronary artery in 13 patients (38.2%), at the right coronary artery in 3 patients (8.8%) and with normal coronary artery in 5 patients (14.7%). This finding did not support the relationship between thickened aortic valve and coronary artery disease at the same side (chi 2 = 0.06, p = 0.96).

CONCLUSIONS

There was a significantly greater incidence of CAD in patients with a thickened aortic valve than in those without. The incidence of CAD in patients with thickened aortic valves increased with age. There was no direct relationship observed between the site of aortic valve thickening and ipsilateral coronary artery stenosis.

Transitional cell and uncommon urothelial carcinoma of renal pelvis/ureter and bladder: low incidence of human papilloma virus

BACKGROUND

Recently, it has been proposed that human papilloma virus (HPV) infection may play a role in the carcinogenesis of bladder urothelial malignancy. However, there is still controversy about the prevalence of HPV in such malignancies. With similar techniques of in situ hybridization (ISH) or polymerase chain reaction (PCR), either high or rare frequency have been detected. To evaluate the prevalence of HPV in the urothelial malignancies based on presentations here, 118 cases of urothelial malignancies were analysed, including those of the renal pelvis and ureter which have rarely been reported before.

METHODS

Non-isotopic ISH technique was used to detect HPV on paraffin sections, including 51 bladder transitional cell carcinoma (TCC), 48 renal pelvic/ureter TCC, 5 bladder adenocarcinoma, 3 bladder small cell carcinoma, 2 bladder undifferentiated carcinoma, 1 multiple synchronous pelvic and ureteric squamous cell carcinoma (SCC) and 8 bladder SCC. An FITC-labelled probe of wide spectrum HPV was used for screening, and probes of HPV 6/11, 16, 18, 31, 33 were used for typing.

RESULTS

By the technique of ISH, wide spectrum HPV was detected in only three of the eight cases of bladder SCC. Of the three positive cases, two were subsequently shown to be uterine cervical SCC with bladder invasion. Therefore, HPV was positive in only one case of primary bladder SCC, occurring in a patient with systemic lupus erythematosus under steroid and cyclophosphamide therapy. Further subtyping was negative for HPV 6/11, 16, 18, 31, and 33. The result indicated that the positive staining by wide spectrum probe was caused by types 30, 35, 45, 51, and/or 52. HPV was not detected in any of the 51 bladder TCC, 48 renal pelvic/ ureter TCC, 5 bladder adenocarcinoma, 3 bladder small cell carcinoma, and 2 bladder undifferentiated carcinoma.

CONCLUSIONS

The results are in agreement with the majority of recent reports which suggest that HPV is unlikely to be involved in the etiology of urothelial malignancies; however, it seems probable that immunosuppressed patients are at greater risk for HPV-associated bladder SCC.

Three-dimensional model of sensory rhodopsin I reveals important restraints between the protein and the chromophore

A structural model is constructed for the integral membrane protein, sensory rhodopsin I (SRI), the phototaxis receptor of the archaeon Halobacterium salinarium. The model is built on the template of the homologous bacteriorhodopsin (BR). The modeling procedure includes sequence alignment, a side chain rotamer search and simulated annealing by restricted molecular dynamics. The structure is in general agreement with previous results from mutagenesis experiments, chromophore substitution and room and cryogenic temperature spectroscopy. In particular, a residue near the beta-ionone ring of the retinylidene chromophore is found to be critical in maintaining the proper isomeric conformation of the chromophore; a layer of residues lying on the cytoplasmic side of the chromophore pocket is found to modulate the restraints around the C13 region of the chromophore, affecting the isomerizations around its 13 = 14 bond that are important to the protein's activity. The restraints in these regions are more stringent in SRI than in BR. The tightened restraints are chiefly due to van der Waals interactions, where the attractive and repulsive components play separable roles. Aromatic residues account for a majority of the restrictive interactions. It is hypothesized that the enhanced barriers due to these restrictions regulate the progress of SRI's photocycle, so that it can couple with the phototaxis reaction chain in the bacterium. A possibility is also suggested that conformational changes of the protein provide the signal recognized by the transducer.

Factors related to detection of blood flow by color Doppler ultrasonography in intussusception

Color Doppler ultrasonography was performed in 125 patients with 134 intussusceptions. Color flow was present in 121 cases of intussusception (group A) and was absent in 13 cases (group B). Young age and duration of symptoms greater than 48 hr were significantly related to the nonvisualization of blood flow detected by color Doppler sonography (P < 0.05). The successful rate of air reduction was significantly higher in group A than in group B (109 of 121 versus 4 of 13). Color Doppler ultrasonography is useful to predict the reducibility of an intussuscepted intestine. The nonvisualization of blood flow by this method is not a contraindication for air reduction.

Protein binding versus protein folding: the role of hydrophilic bridges in protein associations

The role of hydrophilic bridges between charged, or polar, atoms in protein associations has been examined from two perspectives. First, statistical analysis has been carried out on 21 data sets to determine the relationship between the binding free energy and the structure of the protein complexes. We find that the number of hydrophilic bridges across the binding interface shows a strong positive correlation with the free energy; second, the electrostatic contribution of salt bridges to binding has been assessed by a continuum electrostatics calculation. In contrast to protein folding, we find that salt bridges across the binding interface can significantly stabilize complexes in some cases. The different contributions of hydrophilic bridges to folding and to binding arise from the different environments to which the involved hydrophilic groups are exposed before and after the bridges are formed. These groups are more solvated in a denatured protein before folding than on the surface of the combining proteins before binding. After binding, they are buried in an environment whose residual composition can be much more hydrophilic than the one after folding. As a result, the desolvation cost of a hydrophilic pair is lower, and the favorable interactions between the hydrophilic pair and its surrounding residues are generally stronger in binding than in folding. These results complement our recent finding that while hydrophobic effect in protein-protein interfaces is significant, it is not as strong as that observed in the interior of monomers. Taken together, these studies suggest that while the types of forces in protein-protein interaction and in protein folding are similar, their relative contributions differ. Hence, association of protein monomers which do not undergo significant conformational change upon binding differs from protein folding, implying that conclusions (e.g. statistics, energetics) drawn from investigating folding may not apply directly to binding, and vice versa.

Studies of protein-protein interfaces: a statistical analysis of the hydrophobic effect

Data sets of 362 structurally nonredundant protein-protein interfaces and of 57 symmetry-related oligomeric interfaces have been used to explore whether the hydrophobic effect that guides protein folding is also the main driving force for protein-protein associations. The buried nonpolar surface area has been used to measure the hydrophobic effect. Our analysis indicates that, although the hydrophobic effect plays a dominant role in protein-protein binding, it is not as strong as that observed in the interior of protein monomers. Comparison of interiors of the monomers with those of the interfaces reveals that, in general, the hydrophobic amino acids are more frequent in the interior of the monomers than in the interior of the protein-protein interfaces. On the other hand, a higher proportion of charged and polar residues are buried at the interfaces, suggesting that hydrogen bonds and ion pairs contribute more to the stability of protein binding than to that of protein folding. Moreover, comparison of the interior of the interfaces to protein surfaces indicates that the interfaces are poorer in polar/charged than the surfaces and are richer in hydrophobic residues. The interior of the interfaces appears to constitute a compromise between the stabilization contributed by the hydrophobic effect on the one hand and avoiding patches on the protein surfaces that are too hydrophobic on the other. Such patches would be unfavorable for the unassociated monomers in solution. We conclude that, although the types of interactions are similar between protein-protein interfaces and single-chain proteins overall, the contribution of the hydrophobic effect to protein-protein associations is not as strong as to protein folding. This implies that packing patterns and interatom, or interresidue, pairwise potential functions, derived from monomers, are not ideally suited to predicting and assessing ligand associations or design. These would perform adequately only in cases where the hydrophobic effect at the binding site is substantial.

New secoiridoid glucosides from Jasminum lanceolarium

Two new secoiridoid glucosides, the trans-P-coumaroyl and trans-feruloyl esters of 10-hydroxyoleoside, jaslanceosides A (2) and B (3), were isolated from the leaves and stems of Jasminum lanceolarium (Oleaceae) in addition to jasminoside (1) and 10-hydroxyoleoside dimethyl ester (8). The structures of these compounds have been elucidated on the basis of spectral and chemical methods.

Expression of estrogen and progesterone receptors in non-small-cell lung cancer: immunohistochemical study

Estrogen receptor (ER) and progesterone receptor (PgR) have been recognized as being involved in the tumourigenesis of non-small-cell lung cancer (NSCLC). Forty-nine resected NSCLC (39 males and 10 females) were studied immunohistochemically in formalin-fixed, paraffin-embedded sections for ER and PgR. There were 26 squamous cell carcinomas, 22 adenocarcinomas and one adenosquamous carcinoma. 38.8% (19/49)NSCLC had either a positive ER or PgR status of which one was ER+/PgR+, 2 were ER+/PgR- and 16 were ER-/PgR+. There was no statistical difference in hormone receptors status for sex and histological subtypes (p > 0.05). The immunohistochemical assay of formalin-fixed paraffin-embedded sections allows the retrospective analysis of ER and PgR in NSCLC. The ER-/PgR+ status was detected in about one third NSCLC. The discordance between these receptors is suggested to be due to either the presence of functioning variant ER or the constitutive synthesis of PgR independent of estrogen induction in certain ER-/PgR+ NSCLC.

A dataset of protein-protein interfaces generated with a sequence-order-independent comparison technique

While there are a number of structurally non-redundant datasets of protein monomers, there is none of protein-protein interfaces. Yet, the availability of such a dataset is expected to provide an added insight into a number of investigations. First and foremost among these is analyzing the interfaces to obtain their prevailing architectures, the forces that account for the protein-protein associations and their packing considerations. Their comparisons with those of the monomers are likely to shed additional light on protein-protein recognition on the one hand and on the folding of the polypeptide chain on the other. Docking simulations are also expected to benefit from the existence of such a dataset. A major stumbling block to the generation of a dataset of interfaces has been that the interface is composed of at least two chains. Furthermore, in the interfaces, each of the chains might be represented by non-contiguous pieces. Their order in the interfaces being compared might be different as well. This discontinuity stems from the definition of an interface. An interface consists of interacting residues between the chains, and those that are in their vicinity in the supporting scaffold, within a certain distance threshold. This necessarily yields unordered fragments, as well as isolated residues. Our novel, efficient, sequence-order-independent structural comparison technique is ideally suited to handle the task of the generation of a library of structurally non-redundant protein-protein interfaces. As it is computer-vision based, it views atoms as collections of points in space, disregarding their chain connectivity. In this work, 351 interface-families are created. Comparisons of the interfaces, and separately, of the chains which contribute to them, yield some interesting cases. In one of the cases, while two interfaces are similar, the structure of only one of the two chains is similar between the two complexes. The structure of the second chain of the first complex differs from that of the second chain of the second complex. Here the structure of the cleft in the first chain dictates the specific binding interactions. In another case, while the interfaces in the two complexes are similar, both chains composing them differ between the complexes. Lastly, the chains composing the complexes are similar, but the interfaces are dissimilar, providing a set of data for investigations of the favorable orientations of protein-protein associations.

Diagnostic value of C-reactive protein in children with perforated appendicitis

The diagnostic value of serum C-reactive protein (CRP) levels in children with perforated appendicitis was prospectively studied in 78 consecutive patients with histologically confirmed appendicitis. The patients were divided into two groups: group A included 56 patients with perforated appendicitis and group B consisted of 22 patients with simple appendicitis. Serum CRP level and leucocyte count were assayed in all and abdominal ultrasonography was performed in 75. The mean age group A patient was significantly lower than that of group B patients (7.5 vs. 10.4 years, P < 0.001). Group A patients had a significantly higher mean serum CRP levels than group B patients (92 vs. 31 mg/l, P < 0.001), while the mean leucocyte count was comparable in the two groups. Of 75 examined patients, 73 (97%) had a pre-operative sonographic diagnosis of appendicitis.

CONCLUSION

Perforation is a common complication in children with appendicitis, especially in those of young age and with prolonged pain duration. Greatly increased serum CRP levels (> or = 50 mg/l) and abdominal ultrasonography are important diagnostic aids in such patients.