Energy and Enthalpy Distribution Functions for a Few Physical Systems

The present work is devoted to extracting the energy or enthalpy distribution function of a physical system from the moments of the distribution using the maximum entropy method. This distribution theory has the salient traits that it utilizes only the experimental thermodynamic data. The calculated distribution functions provide invaluable insight into the state or phase behavior of the physical systems under study. As concrete evidence, we demonstrate the elegance of the distribution theory by studying first a test case of a two-dimensional six-state Potts model for which simulation results are available for comparison, then the biphasic behavior of the binary alloy Na-K whose excess heat capacity, experimentally observed to fall in a narrow temperature range, has yet to be clarified theoretically, and finally, the thermally induced state behavior of a collection of 16 proteins.

Thermal response of a microgel system

Recent experimental studies [Z. Wu, B. Zhou, Z.B. Hu, Phys. Rev. Lett. 90 (2003) 048304] on an uncharged aqueous poly-N-isopropylacrylamide (PNIPAM) dispersion have shown that this microgel system is sensitive to temperature. This system was also experimentally found to be modeled quite well by microgel particles interacting via a hard-sphere repulsive plus an inverse power (temperature-dependent) attractive potential. To understand theoretically this thermally responsive PNIPAM dispersion, we apply a novel approach [G.F. Wang, S.K. Lai, Phys. Rev. E 70 (2004) 051402] to calculate its thermodynamic phase diagram. Differing from the conventional method in which the boundaries of the coexisting phases are the ultimate target, the present work places emphasis on crosshatching colloidal domains which include the homogeneous phase (gas, liquid or solid), two coexisting phases and perhaps also multi-phases in coexistence. Strategically, this was done by treating the coexisting phases as one composite system whose Helmholtz free energy density is written as the sum of constituent free energy densities each of which is weighed by its respective volume proportion. We show here that by minimizing the composite system's free energy density the phase-diagram domains can all be determined in addition to the phase boundaries customarily obtained by imposing the conditions of equal pressure and equal chemical potential. Also, we present the theoretically predicted phase diagram of PNIPAM dispersion and compare it with the one observed experimentally.

The NHE1 Na+/H+ exchanger regulates cell survival by activating and targeting ezrin to specific plasma membrane domains

NHE1 is a ubiquitously expressed Na+/H+ exchanger, which is important for vital cell functions. Using in vivo models of kidney podocyte injury and renal tubular epithelial cell (RTC) culture systems, we previously demonstrated that NHE1 defends against apoptosis by a mechanism involving ezrin binding to the NHE1 cytoplasmic domain. We now extend the NHE1 role to diabetic mouse models and refine the mechanism of NHE1-dependent ezrin activation. Streptozotocin induced diabetes resulted in greater azotemia, albuminuria and tubulointerstitial pathology in NHE1-deficient swe/swe compared to wild-type control mice. Increased RTC apoptosis was noted in swe/swe mice, suggesting that loss of NHE1 function leads to tubular atrophy, which predicts kidney disease progression. In vitro, proximal RTC derived from swe/swe mice also underwent increased apoptosis in response to staurosporine or a hypertonic environment. Activated ezrin normally resides in the apical domain of the proximal RTC, while NHE1 is a basolateral protein. After NHE1 activation by intracellular acidification or extracellular hypertonicity, confocal immunofluorescence microscopy in polarized LLC-PK1 cells demonstrated transient ezrin localization to lateral membrane domains, where it is positioned to interact with NHE1. We conclude that cell stresses promote NHE1-ezrin interaction, which activate cell survival pathways to prevent apoptosis in diabetic and non-diabetic kidney diseases.

Theoretical studies of the early stage coagulation kinetics for a charged colloidal dispersion

We study the early stage coagulation kinetics for a charged colloidal dispersion which is here modeled by an effective two-body colloid-colloid potential. The colloidal system was physically prepared by choosing sets of colloidal parameters varying in particular the Hamaker constant and the particle's size. The kinetics of coagulation process was driven by the addition of an indifferent electrolyte and assumed to proceed in two quasi-steady steps. In the first step, colloidal particles are destabilized by the presence of a second potential minimum to diffuse from a bulk-stabilized liquid phase to a flocculated phase. In the second step, we assume that different entities are found in the second potential minimum. The entities comprise secondary dimers, secondary dimers undergoing redispersion, and monomers still in singlet states. If, under favorable condition, this kind of interaction-driven diffusive motion continues, a fraction of the secondary dimers will be induced to undergo primary dimers formation in the first deep minimum. Whether or not the latter process occurs is determined either energetically by the potential barrier falling below a prescribed value, say of 15k(B)T, or/and the second potential minimum becoming negligibly small (with a magnitude <k(B)T). A prototype example to exhibit this kind of the coagulation kinetics phenomenon is an aqueous dispersion of polystyrene latex particles. Our detailed analysis on this system showed the connection between the change of rate constants and the reversible flocculation<==>coagulation transition and would throw a fresh light on the use of both the energy and the kinetic criteria for understanding the colloidal stability such as those observed in the liquid-liquid coexistence.

Specific heat and Lindemann-like parameter of metallic clusters: Mono- and polyvalent metals

The Brownian-type molecular dynamics simulation is revisited and applied to study the thermal and geometric properties of four mono- and two polyvalent metallic clusters. For the thermal property, we report the specific heat at constant volume CV and study the solid-liquid-like transition by scrutinizing its characteristic. For the geometric property, we calculate the root mean square relative bond-length fluctuation delta as a function of increasing temperature. The thermal change in delta reflects the movement of atoms and hence is a relevant parameter in understanding the phase transition in clusters. The simulated results for the CV of alkali and aluminum clusters whose ground state structures exhibit icosahedral symmetry generally show one phase transition. In contrast, the tetravalent lead is quite often seen to exhibit two phase transitions, a premelting process followed by a progressive melting. In connection with the premelting scenario, it is found here that those (magic number) clusters identified to be of lesser stability (among other stable ones) according to the second energy difference are clusters showing a greater possibility of undergoing premelting process. This energy criterion applies to aluminum clusters nAl=28 and 38. To delve further into the thermal behavior of clusters, we have analyzed also the thermal variation of deltaT and attempted to correlate it with CV(T). It turns out that the premelting (if exist) and melting temperatures of the smaller size clusters (n less, similar 50) extracted from CV do not always agree quantitatively with that deduced from delta.

Study of a three-stage fluidized bed process treating acrylic synthetic-fiber manufacturing wastewater containing high-strength nitrogenous compounds

Polyacrylonitrile (PAN) is one of the major synthetic fibers commonly used in the mass production of clothing. The chemical synthesis of PAN is carried out by polymerization of the acrylonitrile (AN) monomers with co-monomers such as vinyl acetate, methyl acrylate and cyclohexyl acrylate. Using water quality analysis of the PAN wastewater, high concentration of organic nitrogen was found and the TKN/COD ratios achieved were 0.15-0.26, indicating the complicated biodegradation characteristics for the PAN wastewater. In order to enhance biodegradation of nitrogenous compounds in PAN wastewater, a combined three-stage process of thermophilic anaerobic/anoxic denitrification/aerobic nitrification fluidized bed reactors was employed. The results indicated that the concentration of effluent in the three-stage process of OD and organic nitrogen was 175 mg/L and 13 mg/L, respectively. Furthermore, molecular biotechnology was applied to study the microbial population in the thermophilic anaerobic fluidized bed reactor. From the results of denaturing gradient gel electrophoresis, the diversity of PAN-degrading bacteria would change in different volumetric loading. Furthermore, the bacteria communities in the thermophilic anaerobic fluidized bed reactor were also studied by fluorescence in situ hybridization and confocal laser scanning microscopy. Alpha and delta-Proteobacteria were dominant in the bacteria population, and some high G+C content bacteria and Clostridium could be characterized in this system.

Liquid-liquid and liquid-solid phase separation and flocculation for a charged colloidal dispersion

We model the intercolloidal interaction by a hard-sphere Yukawa repulsion to which is added the long-range van der Waals attraction. In comparison with the Derjaguin-Landau-Verwey-Overbeek repulsion, the Yukawa repulsion explicitly incorporates the spatial correlations between colloids and small ions. As a result, the repulsive part can be expressed analytically and has a coupling strength depending on the colloidal volume fraction. By use of this two-body potential of mean force and in conjunction with a second-order thermodynamic perturbation theory, we construct the colloidal Helmholtz free energy and use it to calculate the thermodynamic quantities, pressure and chemical potential, needed in the determination of the liquid-liquid and liquid-solid phase diagrams. We examine, in an aqueous charged colloidal dispersion, the effects of the Hamaker constant and particle size on the conformation of a stable liquid-liquid phase transition calculated with respect to the liquid-solid coexistence phases. We find that there exists a threshold Hamaker constant or particle size whose value demarcates the stable liquid-liquid coexistence phases from their metastable counterparts. Applying the same technique and using the energetic criterion, we extend our calculations to study the flocculation phenomenon in aqueous charged colloids. Here, we pay due attention to determining the loci of a stability curve stipulated for a given temperature T0, and obtain the parametric phase diagram of the Hamaker constant vs the coupling strength or, at given surface potential, the particle size. By imposing T0 to be the critical temperature T(c), i.e., setting k(B)T0 (=k(B)T(c)) equal to a reasonable potential barrier, we arrive at the stability curve that marks the irreversible/reversible phase transition. The interesting result is that there occurs a minimum size for the colloidal particles below (above) which the colloidal dispersion is driven to an irreversible (reversible) phase transition.

[Thalidomide in the treatment of refractory multiple myeloma: a Dutch study of 72 patients: an antitumor effect in 45%]

OBJECTIVE

To determine the efficacy and side effects of thalidomide in the treatment of refractory multiple myeloma.

DESIGN

Retrospective, descriptive.

METHOD

Data were obtained by means of case research on patients with refractory multiple myeloma who were treated with thalidomide at four regional hematological centres in the period from 1 May 1999 to 31 May 2001. The patients had previously been treated with one, two or three schedules of chemotherapy. The starting dose of thalidomide was 200 mg per day and the dose was increased gradually to a maximum of 800 mg per day depending on the tolerance.

RESULTS

The 72 patients included 43 men and 29 women with an average age of 62 years (range: 38-82 years). The median follow-up was 13 months (range: 2-25). Thalidomide as a single agent was prescribed for 64 patients, of whom 29 (45%) responded; a complete response was achieved in 3 patients, a partial response in 18, and a minor response in 8. In 4 of 11 patients with an extramedullary plasmacytoma a decrease in size was observed. The median duration of the response was 9 months (range: from 2 till > 24). The median overall survival from the start of thalidomide treatment was 9 months. Thalidomide plus dexamethasone was given to 9 patients who did not respond to thalidomide alone, and in 6 of them a reduction of M-protein was then observed. The most frequent adverse effects were constipation, drowsiness, somnolence, dizziness, venous thrombosis and polyneuropathy. Doses of up to 400 mg per day were generally well tolerated.

CONCLUSION

Thalidomide has antitumour activity in refractory multiple myeloma.

[Thalidomide: new uses for an old drug]

Thalidomide was withdrawn from the market in the early sixties because of its teratogenic effects. Despite forty years of research, the mechanism of thalidomide embryopathy has remained unsolved. Thalidomide has various immunomodulatory effects. Thalidomide inhibits TNF alpha production, has T-cell costimulatory properties and modulates the expression of cell surface molecules on leukocytes in vivo. Thalidomide also has anti-angiogenic activity in vivo. Angiogenesis plays an important role in the pathogenesis of both solid tumours and hematologic malignancies such as multiple myeloma and lymphoma. In clinical studies, thalidomide has been used as an inhibitor of angiogenesis. Erythema nodosum leprosum is the only registered indication for the use of thalidomide in the United States of America. Thalidomide is also effective in the treatment of chronic graft-versus-host disease, mucocutaneous lesions in Behçet's syndrome and HIV infections, and multiple myeloma.

Reduced functional expression and molecular synthesis of inducible nitric oxide synthase in rostral ventrolateral medulla of spontaneously hypertensive rats

BACKGROUND

We demonstrated recently that the prevalence of neuronal (nNOS) over inducible (iNOS) nitric oxide synthase activity at the rostral ventrolateral medulla (RVLM), the medullary origin of sympathetic neurogenic vasomotor tone, and the associated dominance of sympathoexcitation over sympathoinhibition underlie the maintenance of sympathetic vasomotor outflow by the endogenous NO. Here, we evaluated the hypothesis that a significant downregulation of iNOS at the RVLM may play a crucial role in the genesis of augmented sympathetic vasomotor tone during hypertension.

METHODS AND RESULTS

Spontaneously hypertensive rats (SHR) and normotensive Wistar-Kyoto (WKY) rats anesthetized with propofol were used. Compared with SHR, the hypotension, bradycardia, or depression in sympathetic vasomotor tone induced by bilateral microinjection of lipopolysaccharide (5 or 10 ng) into the RVLM of WKY rats exhibited significantly shorter-onset latency, appreciably steeper slope, and a greater incidence of mortality. All these effects of lipopolysaccharide (10 ng) were significantly blunted by coadministration of the selective iNOS inhibitor S-methylisothiourea (250 pmol). Reverse transcription-polymerase chain reaction and Western blot analyses further revealed significantly lower iNOS mRNA and protein levels at the ventrolateral medulla in SHR under basal conditions or on activation by lipopolysaccharide (10 ng). Conversely, nNOS mRNA and protein levels remained constant in the RVLM and were comparable in both strains of rats.

CONCLUSIONS

We conclude that a significant downregulation in both functional expression and molecular synthesis of iNOS at the RVLM may underlie the augmented sympathetic vasomotor tone during hypertension.

A novel nomenclature for the hypervariable short tandem repeat APOAI1

A novel nomenclature for the hypervariable microsatellite DNA, APOAI1 locus, is proposed. The complex nature of the repeat unit in this locus results in alleles separated by a single base. Polymerase chain reaction (PCR) products amplified from this locus were separated by single-strand conformation polymorphism (SSCP) electrophoresis. All the single-stranded DNA bands on the SSCP gel were removed from the gel and a second amplification performed. Homozygous DNA fragments amplified from single-stranded DNA were sequenced. From the 100 individuals studied, 30 alleles and 73 genotypes were found. A system of nomenclature for the APOAI1 locus is provided that is logical and in line with previous models. Using the primers described, the locus can be amplified and alleles designated on the basis of size. This system of nomenclature will assist in the exchange of data between laboratories for this locus.

Low-power laser therapy for gastrointestinal neoplasia

The purpose of this study was to evaluate changes in the degree of neoplasia-induced stenosis and clinical symptoms before and after therapy with a contact low-power neodymium yttrium aluminum garnet (Nd:YAG) laser. Fifty patients with pathologically proven gastrointestinal (GI) neoplasia were studied; 21 with benign lesions and 29 with malignant tumors. The low-power contact Nd:YAG laser was applied toward the lesion, using an antegrade method as the scope was moved circumferentially and downward along the length of the lesions, step-by-step. The energy of the laser was 20W, with a duration of 1 to 2 min for each shot. Either the tumor was eradicated completely, or the neoplasia-induced stenosis was recanalized by laser via the endoscope. All benign lesions were completely remitted by laser therapy. The clinical symptoms in the 29 patients with malignant GI neoplasia showed a significant improvement (P < 0.001; Wilcoxon matched-pairs signed-rank test, one-tailed) after laser therapy in comparison with the symptoms before treatment. Malignant GI stenosis treated by laser resulted in recanalization in 93.1% of the 29 patients. Unfortunately, in 1 patient with gastric cancer, the disease progressively worsened after treatment. One of 3 patients with early cancer of the stomach who received laser therapy was found to have distant metastasis 2 years later. A patient with esophageal cancer developed an esophagobronchial fistula that was not a direct complication of the laser effect. Four patients with malignancies died of cancer progression during the 2 years of follow-up. We conclude that the low-power contact laser is a safe, convenient method for the treatment of both benign and malignant tumors. Patients with advanced obstructive lesions have a better quality of life after laser therapy.

Cloning and characterization of a cDNA sequence encoding the precursor of a chlorotoxin-like peptide from the Chinese scorpion Buthus martensii Karsch

A full-length cDNA sequence encoding the precursor of a venom peptide with homology to chlorotoxin (named BmKCT) was isolated from a cDNA library made from the venom glands of the Chinese Scorpion Buthus martensii Karsch. The encoded precursor of BmKCT was 59 amino acid residues long including a signal peptide of 24 residues and a mature toxin of 35 residues with four disulfide bridges. The sequence of BmKCT is similar (68% identities) to that of chlorotoxin isolated from Leiurus quinguestriatus quinquestriatus. BmKCT is the first report of the cDNA sequences encoding four-disulfide-bridged short-chain toxins from Buthus martensuii Karsch so far.

Cloning and characterization of the cDNA sequences of two venom peptides from Chinese scorpion Buthus martensii Karsch (BmK)

From a cDNA library made from venom glands of Chinese scorpions of Buthus martensii Karsch, full-length cDNAs encoding precursors of two venom peptides have been isolated using a cDNA probe synthesized by polymerase chain reaction. Sequence analysis of the cDNAs revealed that one encoded precursor was 85 amino acid residues long including a signal peptide of 19 residues and a mature peptide (named BmK T) of 66 residues, and another encoded precursor was 84 residues long containing the same length signal peptide and a mature peptide (BmK M4 isoform, named BmK M4') of 64 residues. The analysis of amino acid sequence similarity indicated that the BmK T was homologous with both mammalian and insect toxins from BmK scorpion or other scorpions, and the BmK M4' was highly homologous with the members of the mammalian neurotoxin family of BmK, having two point mutations in amino acid residue sequence compared to BmK M4, a natural toxin from BmK.

Drug-induced gastropathy in elderly Taiwanese

BACKGROUND/AIMS

Drug-induced gastropathy was common in developing countries in which drug consumption was heavy. The aim of this study is to evaluate the difference in the distribution of clinical features and endoscopic findings between elderly and non-elderly and to determine the risk factors of drug-induced gastrointestinal mucosal damage in elderly.

METHODOLOGY

Four hundred and fifty patients with gastrointestinal mucosal damages were recruited from the outpatient clinic or emergency room. All patients were confirmed by endoscopic examination with Olympus Videoscope QX-200 or GIF-p20. Patient's clinical symptoms, endoscopic findings and risk factors were collected. Data was analyzed by chi 2 test and expressed as Odds ratio.

RESULTS

The age distribution of gastropathy was predominant at 60-69 years old, and the case number gradually declined as age increased or decreased, respectively. The clinical presentation of asymptomatic bleeding was significantly higher in the elderly than in the non-elderly, while epigastric pain combined with dyspepsia or bleeding was not different between elderly and non-elderly groups. The endoscopic findings of gastric ulcer and erosions were significantly predominant in the elderly group, while no difference was found for duodenal ulcer between these 2 groups. Non-steroidal anti-inflammatory drugs were the popular drug which lead to gastropathy in both elderly and non-elderly groups. Drugs, especially steroids, history of arthritis or peptic ulcer, and alcohol consumption were found to be the risk factors associated with increased risk of gastropathy in the elderly. Stress was also significantly associated with increased risk of gastropathy in the non-elderly. There was no significant difference in smoking habit and use of other drugs between these 2 groups.

CONCLUSIONS

The clinical features of symptoms, endoscopic findings and risk factors of gastropathy varied significantly between the elderly and the non-elderly. Drug-induced gastropathy, especially steroid treatment for arthritis, was a significant risk factor in the elderly. Program for assessment and management of these elderly patients under treatment is important.

Hepatocyte nuclear factor 3beta is involved in pancreatic beta-cell-specific transcription of the pdx-1 gene

The mammalian homeobox gene pdx-1 is expressed in pluripotent precursor cells in the dorsal and ventral pancreatic bud and duodenal endoderm, which will produce the pancreas and the rostral duodenum. In the adult, pdr-1 is expressed principally within insulin-secreting pancreatic islet beta cells and cells of the duodenal epithelium. Our objective in this study was to localize sequences within the mouse pdx-1 gene mediating selective expression within the islet. Studies of transgenic mice in which a genomic fragment of the mouse pdx-1 gene from kb -4.5 to +8.2 was used to drive a beta-galactosidase reporter showed that the control sequences sufficient for appropriate developmental and adult specific expression were contained within this region. Three nuclease-hypersensitive sites, located between bp -2560 and -1880 (site 1), bp -1330 and -800 (site 2), and bp -260 and +180 (site 3), were identified within the 5'-flanking region of the endogenous pdx-1 gene. Pancreatic beta-cell-specific expression was shown to be controlled by sequences within site 1 from an analysis of the expression pattern of various pdr-1-herpes simplex virus thymidine kinase promoter expression constructs in transfected beta-cell and non-beta-cell lines. Furthermore, we also established that this region was important in vivo by demonstrating that expression from a site 1-driven beta-galactosidase reporter construct was directed to islet beta-cells in transgenic mice. The activity of the site 1-driven constructs was reduced substantially in beta-cell lines by mutating a hepatocyte nuclear factor 3 (HNF3)-like site located between nucleotides -2007 and -1996. Gel shift analysis indicated that HNF3beta present in islet beta cells binds to this element. Immunohistochemical studies revealed that HNF3beta was present within the nuclei of almost all islet beta cells and subsets of pancreatic acinar cells. Together, these results suggest that HNF3beta, a key regulator of endodermal cell lineage development, plays an essential role in the cell-type-specific transcription of the pdx-1 gene in the pancreas.

Endoscopic variceal ligation in prophylaxis of first variceal bleeding in cirrhotic patients with high-risk esophageal varices

To determine the efficacy of endoscopic variceal ligation (EVL) in prophylaxis on the rate of first esophageal variceal bleeding, we conducted a prospective, randomized trial in 126 cirrhotic patients with no history of previous upper gastrointestinal bleeding and with esophageal varices endoscopically judged to be at high risk of hemorrhage. The end-points of the study were bleeding and death. Life-table curves showed that prophylactic EVL significantly diminished the rate of variceal hemorrhage (12/62 [19%] vs. 38/64 [60%]; P = .0001) and overall mortality (17/62 [28%] vs. 37/64 [58%]; P = .0011). The 2-year cumulative bleeding rate was 19% (12/ 62) in the EVL group and 60% (38/64) in the control group. The 2-year cumulative mortality rate was 28% (17/62) in the EVL group and 58% (37/64) in the control group. Comparison of Kaplan-Meier estimates of the time to death of both groups showed significantly lower mortality in the ligation group (P = .001). Patients undergoing EVL had few treatment failures and died mainly of hepatic failure. The lower risk in the EVL group was attributed to a rapid reduction of variceal size. Prophylactic EVL was more efficient in preventing first bleeding in patients with good condition (Child A) than in those with decompensated disease (Child B and C). We conclude that prophylactic EVL can decrease the incidence of first variceal bleeding and death over a period of 2 years in cirrhotic patients with high-risk esophageal varices.

In vitro and in vivo growth inhibition of SC-M1 gastric cancer cells by retinoic acid

Retinoids are differentiating agents that have been used successfully for the treatment of acute promyelocytic leukemia. When combined with interferons, they are active in preventing second malignancies in patients with head and neck cancer. Our previous studies have demonstrated cytostatic effects of alltrans-retinoic acid (tRA) on SC-M1 gastric cancer cells in vitro. The activity of tRA and 13-cis-retinoic acid (cRA) on SC-M1 cells was compared both in vitro and in vivo in this study. Measurement of total cellular DNA was used to determine cell growth in vitro. The effect of retinoic acid on tumor growth was evaluated by implanting sustained release tRA or cRA pellets into athymic nude mice. The results showed that tRA was more potent than cRA in suppressing the growth of SC-M1 gastric cancer cells in vitro. Both tRA and cRA were effective in suppressing the growth of SC-M1 tumors in athymic nude mice. No change in the differentiation status and cell cycle phase distribution in excised tumors was observed. Side effects such as bone fractures and weight loss were observed in mice of both treatment groups. The results suggest that retinoic acid may provide therapeutic advantages for the treatment of gastric cancer.

Effect of verapamil on renal haemodynamics in a portal hypertensive rat model

In order to investigate the effects of verapamil on renal haemodynamics in rats with portal hypertension, verapamil was given at either a low (0.2 mg/kg) or high (2 mg/kg) dose to rats after portal vein ligation. An approximate 12% decrease in mean arterial pressure followed administration of low dose verapamil, with a significant decrease in cardiac output and renal blood flow, as well as reduced portal pressure, observed; these signs were all indicative of a rise in renal vascular resistance. In contrast, the marked fall in both mean arterial pressure and cardiac output with high dose verapamil, accompanied by a significant decrease in portal pressure and no change in renal blood flow, suggests a reduction in renal vascular resistance. This study shows that the acute effects of verapamil on renal haemodynamics may vary with the dose used. Also, acute verapamil administration tends to decrease renal blood flow to alter the autoregulation of the kidney; thus, caution should be taken in the clinical use of verapamil in the treatment of cirrhosis with portal hypertension.

Relationship between C14 urea breath test values and solid-phase gastric emptying time in non-ulcer dyspepsia patients

BACKGROUND

Non-ulcer dyspepsia (NUD) is a poorly understood syndrome often found with endoscopic evidence of gastritis; Helicobacter pylori (Hp) is a common and important cause of gastritis. In the recent literature, gastric hypomotility is thought to be a cause of NUD. Thus, this investigation studied the relationship between Hp and delayed gastric emptying in NUD patients.

METHODS

Using a radionuclide-labelled solid meal to calculate gastric emptying time (GET) of 78 NUD patients. The carbon-14 urea breath test (C14 UBT) was used to quantitate Hp infection.

RESULTS

The prevalence of Hp infection in patients with NUD reached 59%. There was a strong association of Hp infection with advanced age (p = 0.0091). There was no significant difference between solid-phase GET and C14 UBT values among three different age groups (young, middle, old) of NUD patients. There was no difference among sex, age, body weight and solid-phase GET between Hp-positive and Hp-negative NUD patients. However the solid-phase GET was significantly prolonged in patients with NUD, compared with the controls.

CONCLUSIONS

Solid-phase GET is not correlated with the C14 UBT values, and Hp gastric colonization does not account for dyspeptic syndrome in NUD patients.

Growth regulation by all-trans-retinoic acid and retinoic acid receptor messenger ribonucleic acids expression in gastric cancer cells

Retinoic acid has been recognised as a pivotal compound in cell differentiation, proliferation and malignant transformation. We investigated the effects of all-trans-retinoic acid on cell growth and the expression of retinoid nuclear receptor mRNAs in gastric cancer cells in vitro. Cell growth was quantified by measuring total cellular DNA. The growth of two of the five gastric cancer cell lines tested (SC-M1 and TSGH9201) was inhibited by all-trans-retinoic acid at concentrations ranging from 1 x 10(-8) M to 1 x 10(-6) M. Growth inhibition was associated with G0/G1 phase arrest as determined by flow cytometric analysis. Northern blot analysis showed that all five cell lines expressed mRNA for retinoic acid receptors alpha and retinoic x receptor alpha and beta. Retinoic acid receptor beta mRNA was only expressed in TSGH9201 and TMK-1 gastric cancer cell lines. Two RAR gamma mRNA transcripts (3.2 and 3.0 kb) were detected in SC-M1 and TSGH9201 cells. RA-resistant cells had markedly decreased levels of the 3.2 kb RAR gamma transcript. All-trans-retinoic acid had a cytostatic effect on the growth of some gastric cancer cells, which may be associated with the expression of retinoic acid receptors.

Morphological study of fetal neocortical transplant grafted to the cerebral corresponding area in young rats. Differentiation of immature neurons and reciprocal connections of fibers between graft-host brain

The fetal neocortical transplant (E15-17 days gestation) of Wistar rat was grafted to the corresponding neocortical region (frontal-parietal lobe) of the same strain in young rats (4-5 weeks old). On the 7th, 15th, 30th, 60th, 150th day after transplantation, the sections cut through the middle area of graft-host brain were examined by HE, Nissl, Glees stain, immunohistochemical technique for GFAP and NF, Nissl, Glees stain, immunohistochemical technique for GFAP and NF, acetylcholinesterase (AChE) histochemistry as well as horseradish peroxidase (HRP) retrograde tracing with light microscope. Some of the sections were also examined with TEM. The result showed that most immature neurons within the graft can survive, grow, differentiate and mature, and are similar to the structure of the neocortical neurons of host brain. This study also provides patterns of integration of the interface between graft-host brain varying with the proliferation of reactive astrocyte as well as graft-host reciprocal connection of fibers.

Primary carcinoma of the gallbladder: a review of 10 years of experience at Tri-Service General Hospital

Thirty-two cases of primary carcinoma of the gallbladder proven by surgery and pathological biopsy between January 1982 and June 1991 at the Tri-Service General Hospital, Taipei, were analyzed retrospectively. There were 16 male and 16 female patients with a mean age of 66.1 years. The most common clinical manifestations were right upper quadrant abdominal pain and poor appetite. The most common laboratory finding was an elevation of alkaline phosphatase. The preoperative diagnostic rate of this series was 46.9% (15/32 cases), through use of abdominal sonography, computed tomography, endoscopic retrograde cholangiopancreatography and celiac angiography. The coexisting gallstone incidence was 65.6% and the resectability rate, 59.4%. The histological classifications were adenocarcinoma with variable differentiation in 31 cases, and undifferentiated adenocarcinoma in one. The liver was the most common site for metastasis (53.1%), followed by lymph nodes at porta hepatis (21.9%), omentum (12.5%), peritoneum (9.4%), lung (6.3%), colon (3.1%) and duodenum (3.1%). According to the Nevin's staging system, three patients were in stage I and all survived more than five years. Of the two patients in stage II, one survived longer than five years and the other survived longer than seven months. There were three cases in stage III: one patient died of metastasis eight months postoperatively, while the other two cases lived for seven and nine and a half months respectively. There were 24 cases in stage IV and stage V, all of them died less than six months after diagnosis. Poor prognosis for patients with primary carcinoma of the gallbladder makes early diagnosis and treatment important.

An experimental study of trachea anastomosis in rabbits using carbon dioxide laser

A technique of sutureless trachea anastomosis in rabbits using carbon dioxide laser was reported herein. In 6 rabbits with laser-assisted trachea anastomoses, only one was found to have slight anastomotic stenosis after operation, whereas 6 rabbits with conventional sutures all were found to have anastomotic stenosis. Results show that laser-assisted trachea anastomosis has certain advantages over the conventional suturing technique, thereby finding wide application in clinical tracheal reconstruction and lung transplantation.

Morphometric studies of parietal cells in cats before and after lesser-curvature seromyotomy

A modified, highly selective vagotomy-seromyotomy of the lesser curvature of the stomach was performed on five groups of cats. The horseradish peroxidase (HRP) tract-tracing method was used to detect the regeneration or reinnervation of vagal nerve branches. Morphological changes to the parietal cells and to the gastric mucosa were also examined by light and electron microscopy. Following surgery, the cats were sacrificed at the fourth, eighth, twelfth, sixteenth and the twentieth week. At the sixteenth week, partial regeneration of vagal nerve branches was found. Between the fourth and the twelfth week there was a significant increase in the number of parietal cells per 0.1 mm-wide of mucosa column and in the volume fraction of the mucosa made up of parietal cells. Of the four types of parietal cells, "stimulated", "partially stimulated", "returning" and "resting", the resting type was predominant after seromyotomy, especially between the fourth and the twelfth week. Based on the above observation, we concluded that the modified lesser-curvature seromyotomy depresses the function and responsiveness of the parietal cells despite an increase in their number and in their volume fraction.

High energy laser irradiation and electric surgery for obstructive gastrointestinal cancer

A total of 35 patients with advanced obstructive gastrointestinal cancer received monopolar electrosurgery and Nd: YAG laser therapy from January 1985 to June 1988. These included 13 cases of esophageal cancer (U/3 6, M/3 2, L/3 5), 14 case of gastric cancer (cardia 7, corpus 3, antrum 4), and 8 cases of rectal cancer. Twenty (esophageal 9, stomach 8, rectal 3) of 35 patients had much improved results, with the size of the lesion reduced over 90%, and the endoscope could smoothly pass through the stenotic area after electrosurgery or laser therapy. The other 12 patients had partially improved results with the tumor size being reduced 50-90% and the patients could take semiliquid food easily. Both groups of much improved or partial improved had a statistically significant difference (P less than 0.01) compared to the group of failures to treatment. Two patients developed bleeding after treatment. Twenty-one patients died of causes other than complications of electrosurgery or laser therapy. The average survival was 6.8 months. Nd: YAG laser and electrosurgery can provide good palliative results and contribute to a good quality of life in advanced obstructive gastrointestinal cancer.

A clinical controlled trial of endoscopic sclerotherapy for repeated esophageal variceal bleeding

Thirty-seven patients with postnecrotic cirrhosis of the liver and 13 patients with primary hepatoma were proven to have repeated bleeding from ruptured esophageal varices. Clinically controlled trials were performed by assigning patients to either sclerotherapy or control arms (25 patients each). Combined intra-variceal and para-variceal injection before an upper endoscopic examination was performed in the sclerotherapy group. In all 25 sclerotherapy cases (100%) hemostasis was successful, which was a statistically significant success rate compared to the control group (52.0%) (p less than 0.01). In the sclerotherapy group 20% (5/25 cases) developed rebleeding, which was less than the 48.0% (7 cases of continuous bleeding and 5 cases of rebleeding) of the control group (p less than 0.05). Four cases (16.0%) in the sclerotherapy group died of erosive gastritis with massive bleeding, compared to 8 fatalities (32.0%) in the control group, because of uncontrolled esophageal variceal bleeding. Endoscopic sclerotherapy is a very effective method for arresting bleeding esophageal varices, and for decreasing the rebleeding rate.