[Pathology of endothelium, extracellular matrix and smooth muscle in gastric coronary vein of cirrhotic patients]

Immunohistochemical stain was used to observe the pathology of endothelium, extracellular matrix (ECM), vascular smooth muscle cell (VSMC) in gastric coronary vein of 30 cirrhotic patients and 10 controls. There was widespread destruction to endothelium, intravenous thrombosis, aggregation of pericyte, smooth muscle hyperplasia, and increased FN, LN, collagen IV and smooth muscle actin in the wall of the coronary vein in cirrhotic patients. The thickness of the wall and its smooth muscle were 3.07 +/- 1.03 mm and 2.31 +/- 0.76 mm respectively in cirrhotic patients, and 1.65 +/- 0.49 mm and 0.88 +/- 0.20 mm in non-cirrhotic patients (P < 0.01). Based on these observations a new concept of portal hypertensive vasculopathy was put forward.

Tumor necrosis factor alpha: posttranscriptional stabilization of WAF1 mRNA in p53-deficient human leukemic cells

The p53 protein directly regulates the expression of the WAF1 (wild-type p53-activated fragment 1) protein which is a cyclin-dependent kinase inhibitor (CDK1). DNA damaging agents such as ionizing or UV radiation, and some chemical agents induce WAF1 in wild-type p53 containing cells, thereby halting cell cycle progression. WAF1 expression is also induced through a p53-independent pathway. Tumor necrosis factor alpha (TNF alpha) is a cytotoxic/cytostatic compound for some human cancer cells. We examined a series of myeloid leukemic cell lines that expressed either no p53 (HL-60, K562) or mutant inactive p53 (KG-1, KCL22,THP-1, U937). The KG-1, HL-60, K562, and KCL22 myeloid leukemic cells increased their levels of WAF1 mRNA in the presence of TNF alpha. We focused on KG-1 cells to determine how TNF alpha modulated WAF1 expression. WAF1 mRNA increased in a dose-dependent manner in the cells after exposure to increasing concentrations of TNF alpha, and this increase occurred in the absence of new protein synthesis. An increase of WAF1 protein and a concominant decrease of cyclin-dependent kinase 2 activity also was found in KG-1 cells. Flow cytometry using 5-bromo-2'-deoxyuridine showed an increase in the proportion of TNF alpha- treated KG-1 cells in the G0/G1 phase of the cell cycle. TNF alpha enhanced the rate of WAF1 transcription only 1.4 fold in TNF alpha-treated KG-1 cells as compared to untreated cells. Notably, however, the half-life (t 1/2) of WAF1 mRNA in TNF alpha-treated cells was 2.5 hours as compared to 0.5 hours in untreated cells. These results indicate that TNF alpha increases WAF1 levels at least in part via a postttranscriptional stabilization of the mRNA; and TNF alpha may mediate its cytostatic effects through WAF1 in some cell types.

Portal hypertensive vascular lesions

The aim of present study is to assess the pathological changes of gastric coronary vein in cirrhotic patients (n = 30) by immunohistochemical and morphological observation. The damage to endothelium, hypertrophy and hyperplasia of smooth muscle and increament of ECM were found in gastric coronary vein of cirrhotic patients. The vessel wall hardened and thickened with decrease of elasticity. The results showed that the portal hypertension could accompany with portal hypertensive vascular lesions.

[Methylene blue staining in fiberoptic bronchoscopy in the diagnosis of bronchial tumors]

47 patients were stained by using methylene blue in fiberoptic bronchoscopy. Of these, 35 had central lung cancer, and 12 bronchitis. 40 patients with central lung cancer were detected by general fibreoptic endoscopy. The results demonstrated that normal bronchial mucosa was not stained, 97.14% central malignant bronchial tumors stained, and 8.33% bronchitis stained. X2test showed the marked difference. Positive diagnosis was 97.06% in biopsy specimens stained, it was higher than 77.05% in the general investigated (P < 0.05). Using methylene blue in fiberoptic bronchoscopy would help diagnose central lung cancer, determine tumors limits, permit accurate biopsy. The stain was not related to the pathological classification, differentiation of cancer cells, and classification of clinical pathology (P > 0.05).

Relationship between chondroitin sulfate proteoglycan and coronary atherosclerosis in the youth

OBJECTIVE

To study the relationship between chondroitin sulfate proteoglycan (CSPG) and coronary atherosclerosis in youth.

MATERIAL AND METHODS

Immunohistochemistry of chondroitin sulfate proteoglycan and SM-alpha-actin was performed on 39 human coronary arteries, including normal vessels and vessels with fatty streaks, intermediate lesions and plaques. Some of the lesional vessels were taken for beta-lipoprotein immunohistochemical study. CSPG contents were quantitated by image analyzer and the coronary arteries from one heart were processed for immunoelectron microscopy.

RESULTS

The range of CSPG distribution was extensive and CSPG area density was increased significantly in the intima with atherosclerotic lesions. The increase of CSPG was parallel to the numbers of smooth muscle cell (SMC) with positive SM-alpha-actin reaction and was likely related to the phenotype transformation of SMC. Similar distribution of beta-lipoprotein and CSPG were found within the lesional regions.

CONCLUSIONS

The increase of CSPG in atherosclerotic lesion may be an important factor resulting in the deposition of lipids in the vascular wall so as to promote the formation and development of atherosclerosis.

Analysis of p16INK4a and its interaction with CDK4

The interaction between cyclin-dependent kinase 4 (CDK4) and its inhibitor p16INK4a (p16) was studied by random mutagenesis and yeast two-hybrid system. The gene encoding p16 was mutagenized randomly and the amino acid changes that affect the binding of p16 to CDK4 were identified. Several amino acid residues were shown to be important for the binding and many of these changes occur at residues conserved in all known human p16 family proteins Most of the mutant p16 proteins that failed to bind to CDK4 contained multiple amino acid changes, and these alterations were observed throughout the entire gene with no apparent mutational patterns or hot spots. Some of the mutations that moderately reduced the binding activity severely affected the kinase-inhibitory activity of p16.

Order statistics learning vector quantizer

We propose a novel class of learning vector quantizers (LVQs) based on multivariate data ordering principles. A special case of the novel LVQ class is the median LVQ, which uses either the marginal median or the vector median as a multivariate estimator of location. The performance of the proposed marginal median LVQ in color image quantization is demonstrated by experiments.

Experimental liver cancer: improved response after hepatic artery ligation and infusion of tumor necrosis factor-alpha and interferon-gamma

BACKGROUND

The aim of this study is to investigate whether regional infusion of tumor necrosis factor-alpha (TNF-alpha) and interferon-gamma (IFN-gamma) could improve the therapeutic results of hepatic artery ligation (HAL) on liver cancer in a rat model.

METHODS

Morris hepatoma 3924A was implanted intrahepatically in 50 ACI rats. Two weeks after tumor implantation, 40 rats underwent hepatic artery cannulation and ligation. The cannula was connected to an infusion port implanted subcutaneously. Animals were then divided into four groups of 10 each to receive seven daily intraarterial injections of IFN-gamma 100,000 IU/rat/day (HAL + IFN group), TNF-alpha 30 micrograms/rat/day (HAL + TNF group), IFN + TFN (HAL + IFN + TNF group), or normal saline solution (HAL group). The remaining 10 rats received a laparotomy only and served as untreated controls. Tumor volume, viable tumor area, and histopathology were assessed after 3 weeks.

RESULTS

The tumor growth was significantly retarded in the HAL group compared with the controls (tumor volume 683 +/- 245 mm3 vs 2424 +/- 596 mm3, p < 0.05 ANOVA). HAL + TNF (221 +/- 93 mm3) and HAL + IFN + TNF groups (74 +/- 31 mm3), but not the HAL + IFN group (493 +/- 164 mm3), were much more effective than the HAL group in controlling tumor growth (p < 0.05). HAL + IFN + TNF achieved the best tumor control resulting in a 60% tumor-free rate (p < 0.05 vs all other groups).

CONCLUSIONS

These data suggest that HAL combined with regional infusion of TNF-alpha and IFN-gamma significantly reduces tumor growth in a rat liver model. This attractive concept of combined modality therapy may have utility in the clinical setting in instances of unresectable liver cancer.

Developmental activity variations of DNA polymerase alpha, delta, epsilon in mouse forebrains and spleens

The levels of DNA polymerase alpha, delta, epsilon were examined in the neonatal mouse forebrains and spleens. The levels of DNA polymerase alpha were determined by the difference of polymerase activity in the absence and the presence of alpha specific inhibitor, BuPdGTP, or its monoclonal antibody. The levels of DNA polymerase delta were determined in H.A fractions after separating it from the other two enzymes. The levels of DNA polymerase epsilon were identified in H.A fractions by the use of alpha-monoclonal antibody or BuPdGTP. Results showed that in the mouse forebrain DNA polymerase alpha, delta, epsilon activities are the highest before birth, decline sharply following birth and are very low on the 8th day and hardly detectable on the 17th day; as for the mouse spleen, however, DNA polymerase alpha, delta, epsilon activities are the lowest at birth, increase rapidly after birth and reach their maxima on the 8th day and then decline gradually but remain in higher levels. These results not only prove that DNA polymerase alpha and delta take part in cell DNA replication but also suggest that DNA polymerase epsilon is involved in DNA replication.

Beneficial effects of growth hormone and insulin-like growth factor-1 in experimental heart failure in rats treated with chronic ACE inhibition

The effects of growth hormone (GH) plus insulin-like growth factor-1 (IGF-1) were tested in an experimental model of cardiac failure treated with chronic angiotensin-converting enzyme (ACE) inhibition. Myocardial infarction was induced in rats by left coronary artery ligation. Two weeks after ligation, the animals received either captopril (2 g/L in drinking water) or water for 3 months. The rats were then given either GH (2 mg/kg/day) plus IGF-1 (2 mg/kg/day) or vehicle for 14 days. Captopril treatment decreased mean arterial pressure (MAP), left ventricular end-diastolic pressure (LVEDP) and systemic vascular resistance (SVR) (p < 0.05), and increased cardiac index (CI) and stroke volume index (SVI) (p < 0.05). GH/IGF-1 or captopril+GH/IGF-1 treatment decreased MAP, LVEDP, and SVR (p < 0.05), and increased left ventricular maximum dP/dt, CI, and SVI (p < 0.05). The increases in CI and SVI were significantly greater in the captopril+GH/IGF-1-treated animals than in those treated with captopril alone (p < 0.05). The beneficial effect of captopril in reducing cardiac hypertrophy was preserved in the captopril+GH/IGF-1 group. The results indicate that GH/IGF-1 and captopril can improve cardiac performance in congestive heart failure by independent and complementary mechanisms.

[Study on the reversing effect of tripiperaquine on human multidrug resistant leukemic cell line K562/A02]

K562/A02 is a Cell line with multi-drug resistance established in our laboratory bey long term induction with adriamycin. In this paper, reversal of MDR in K562/A02 cell line by tripiperaquine is reported. The cytotoxicity and intracellular concentration of daunorubicin (DNR) in K562/A02 were measured by MTT colorimetric assay and spectrofluorimetry. The results showed that the sensitivity of K562/A02 to DNR was greatly enhanced by tripiperaquine at 10 micrograms/ml, with an 11-fold increase in cytotoxic activity. The intracellular concentration of DNR in K562/A02 was significantly increased after coincubation with 20 mumol/L tripiperaquine for 3 hours. Our results suggest that tripiperaquine might be used in clinical trial to reverse MDR.

Using oligonucleotide probe arrays to access genetic diversity

As the Human Genome Project and related efforts identify and determine the DNA sequences of human genes, it is important that highly reliable and efficient mechanisms are found to access individual genetic variation. It is only through a greater understanding of genetic diversity that the true benefit of the Human Genome Project will be realized. One approach, hybridization to high-density arrays of oligonucleotides, is a fast and effective means of accessing this genetic variation. Light-directed chemical synthesis has been used to generate miniaturized, high-density arrays of oligonucleotide probes. Application-specific oligonucleotide probe array designs have been developed for the rapid screening of characterized genes. Dedicated instrumentation and software have been developed for array hybridization, fluorescence detection and data acquisition and analysis. In a specific and challenging application, oligonucleotide probe arrays have been used to screen the reverse transcriptase and protease genes of the highly polymorphic HIV-1 genome to explore genetic diversity and detect mutations conferring resistance to antiviral drugs. Results from this application strongly suggest that oligonucleotide probe arrays will be a powerful tool for rapid investigations in sequence checking, pathogen detection, expression monitoring and DNA molecular recognition.

Pharmacology of volume regulation following hypotonicity-induced cell swelling in clonal N1E115 neuroblastoma cells

When exposed to hypotonic solutions, clonal N1E115 neuroblastoma cells initially swell and later undergo a regulatory volume decrease (RVD). We studied the effects of a variety of transport inhibitors on the time course of cross-sectional area of N1E115 cells exposed to a solution of reduced osmolarity (pi = 186 mosm). Application to the bath of either: (i) blockers of net K efflux through K channels (e.g. isotonic KCl or 20 mM TEA); or (ii) blockers of net efflux through anion channels (e.g. isotonic methanesulfonate, 10 microM DIDS or 100 microM IAA-94) all prevent RVD. In contrast, ouabain (a Na+/K+ pump blocker), bumetanide (a Na+/K+/Cl- cotransporter blocker) and SITS (a HCO3-/Cl- exchange blocker) do not. These data support the involvement of these channels over pumps or exchangers in solute exit during RVD. Only variable block of RVD was achieved using blockers of stretch activated non-selective cation C+ (SA) channels (i.e., amiloride and gadolinium, Gd3+) or a membrane permeant Ca chelator (BAPTA-AM) suggesting that neither the opening of C+ (SA) channels nor a global rise in cytosolic Ca2+ is critical for triggering RVD.

Growth hormone improves cardiac performance in experimental heart failure

BACKGROUND

Growth hormone has been shown to increase maximum isometric active force of the left ventricular papillary muscle of rats in vitro. Administration of growth hormone causes an increase in myocardial contractility in normal humans. Our preliminary study suggests that treatment with growth hormone results in increased ventricular contractility in rats with left ventricular dysfunction. In the present study, the effects of growth hormone on cardiac function, including cardiac output, stroke volume, and peripheral vascular resistance, were determined in a rat model of heart failure.

METHODS AND RESULTS

Ligation of the left coronary artery or sham operation was performed; 4 weeks after surgery, recombinant human growth hormone (2 mg/kg per day SC) or vehicle then was administered for 15 days. The animals were catheterized after 13 days of the treatment. Cardiac output, measured by a thermodilution method, and other hemodynamic parameters were measured in the conscious animals 2 days after catheterization. The infarct sizes induced by left coronary ligation were comparable between growth hormone-treated and vehicle-treated rats. Six weeks after ligation, rats treated with vehicle exhibited significant decreases in cardiac index, stroke volume index, and left ventricular maximum dP/dt and increases in left ventricular end-diastolic pressure compared with sham rats. In the ligated rats, treatment with growth hormone increased cardiac index, stroke volume index, and left ventricular maximum dP/dt (P < .05) and reduced left ventricular end-diastolic pressure and systemic vascular resistance (P < .05). In sham rats, growth hormone slightly reduced arterial pressure but did not significantly alter cardiac performance. There was no significant difference in heart rate between the experimental groups.

CONCLUSIONS

These results suggest that growth hormone treatment may improve cardiac function by both increased myocardial contractility and decreased peripheral vascular resistance in heart failure.

Preservation of postprandial intestinal hyperemic response after small bowel transplantation

Postprandial intestinal hyperemia (PIH) is a normal physiological phenomenon and is thought to accommodate the increased intestinal metabolic demand during food digestion. Lack of such a response could lead to malabsorption. The purpose of this study was to determine whether transplanted intestine retains the ability to mediate PIH. Nineteen rats with syngeneic orthotopic small bowel transplantation (SBT) and 13 normal controls were further divided into two subgroups to receive gastric gavage of either 2 mL of Ensure Plus (EP) high-calorie liquid nutrition or 2 mL of normal saline. Intestinal blood flow was determined before, and 20 and 45 minutes after the gavage, employing a colored microsphere technique. The results showed that basal blood flow to the transplanted intestine (56.7 +/- 26.7 mL/min/100 g) was similar to that of normal intestine (64.2 +/- 35.8 mL/min/100 g; P > .1). EP feeding elicited a marked increase in intestinal blood flow (PIH phenomenon) in both normal and SBT animals. The magnitudes of flow increase were similar for the two groups (249 +/- 99% versus 241 +/- 76% of baseline 45 minutes after EP feeding in the normal and transplanted intestine, respectively; P > .1). The results indicate that hyperemic response to feeding is normal in syngeneic orthotopic SBT.

Mutational effects on the p16INK4a tumor suppressor protein

Several point mutations of p16INK4a were studied by site-specific mutagenesis and functional analysis to assess the effects of these mutations on the function of the protein. These mutations were reported in several malignancies. Three deletional mutants of p16INK4a were also analyzed to reveal the relationship between p16INK4a and p15INK4b and to test the importance of the ankyrin repeats observed in both proteins. We studied the activity of these mutants using the yeast two-hybrid system and an in vitro kinase assay. Our results suggest that point mutations in the conserved ankyrin consensus affect the activity of p16INK4a. However, not all of the point mutations observed in tumors have a detectable effect on the activity. The COOH-terminal region of p16INK4a is not required for the protein to bind and to inhibit CDK4, but the deletion of the 4th ankyrin repeat abolished the activity completely.

Reduced recovery of a Cryptococcus neoformans adherence mutant from a rat model of cryptococcosis

Stable mutants of Cryptococcus neoformans (strain CSF-1) induced by treatment with ultraviolet light and nitrosoguanidine were isolated that demonstrated reduced adherence to glial cells in culture. Adherence of the mutants, as measured by a radiometric assay, was reduced by 50-70% of that attained for the parent CSF-1 strain. The adherence mutants appeared to be phenotypically similar to the CSF-1 strain. However, all but one mutant (designated as CSF-23) demonstrated slightly slower growth rates than the wild-type strain. The CSF-1 and CSF-23 strains were injected intravenously and intratracheally into normal rats and rats immunosuppressed by cyclophosphamide treatment, and the organ distribution and recovery of viable yeasts determined over 2-96 h. During this relatively short period of observation the majority of the yeasts were localized in the lungs. By either route of injection, the recovery of the CSF-23 adherence mutant was reduced by as much as 90% of that obtained for the wild-type strain. The results indicated that host cell adherence may be important for the persistence of cryptococci in tissue and that further studies with the adherence mutants are warranted.

Protection against endotoxic shock by bactericidal/permeability-increasing protein in rats

Bactericidal/permeability-increasing protein (BPI) is a neutrophil primary granule protein that inhibits effects of LPS in vitro. The current study examined the effects of BPI on hemodynamics, mortality, and circulating endotoxin and cytokines in conscious rats with endotoxic shock. Catheters were implanted into the right femoral artery and vein. 1 d later, human recombinant BPI (10 mg/kg) or vehicle was intravenously injected immediately, 30 min, or 2 h after intravenous injection of LPS (7.5 mg/kg). Mean arterial pressure (MAP) and heart rate were monitored and blood was collected before and after injection. BPI given immediately or 30 min after LPS prevented the LPS-induced reduction in MAP at 4-8 h and markedly reduced mortality. BPI given 2 h after LPS injection had no protective effect. BPI treated immediately after LPS reduced the circulating levels of endotoxin and IL-6 but increased the circulating levels of TNF. We propose that BPI exerts its protective effect through a TNF-independent mechanism, by inhibiting endotoxin-stimulated production of IL-6.

Characterization of an avian bone sialoprotein (BSP) cDNA: comparisons to mammalian BSP and identification of conserved structural domains

Bone sialoprotein (BSP) is one of the major noncollagenous proteins found in mineralized vertebrate tissue. It is an acidic glycoprotein containing a high sialic acid content and is phosphorylated on several of its Ser and Thr residues. While it has been extensively characterized from various mammalian species, little is known about its sequence or expression in lower vertebrates. The cloning and characterization of several cDNAs encoding the chicken bone sialoprotein are reported here. A partial cDNA clone encoding the carboxyl terminus of the protein was initially isolated from a lambda GT11 expression library using a polyclonal antibody gains BSP purified from chicken bone matrix. Subsequently, several additional clones were obtained by further screening and by reverse transcription polymerase chain reaction (RT-PCR). Three overlapping clones encompassing about 1 kb, which included the complete coding sequence for BSP, were analyzed. The deduced amino acid sequence revealed that chicken BSP contains 276 amino acid residues. Although the overall identity between chicken and mammalian BSP is only approximately 39%, the diversity in amino acid sequence occurs mostly between the major functional domains of this molecule. These domains include: (1) three acidic poly-Glu regions; (2) two tyrosine-rich domains, which may be sites for protein sulfation; (3) several casein kinase II phosphorylation sites; (4) an Asn glycosylation site; and (5) an RGD cell-binding motif. Of interest in the chicken BSP is the identification of two additional RGD motifs within the avian sequence, unlike the mammalian forms of BSP which has only one.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of growth hormone in rats with postinfarction left ventricular dysfunction

Growth hormone may affect cardiac function. In rats, chronic hypersecretion of growth hormone leads to increased maximum isometric contractile force of the left ventricular papillary muscle in vitro. In humans, administration of growth hormone can increase myocardial contractility. However, cardiac effects of growth hormone in heart failure or cardiac dysfunction have not been studied to date. The current study was to evaluate the cardiac effects of growth hormone in conscious rats with postinfarction left ventricular dysfunction and sham controls. Ligation of the left coronary artery or sham operation was performed, then 4 weeks after surgery, recombinant human growth hormone (2 mg/kg/day, SC) or vehicle was administered for 15 days. Catheters were implanted 13 days after treatment with growth hormone or vehicle. Hemodynamic parameters were measured in conscious rats 2 days after catheterization. In vehicle-treated rats, left ventricular systolic pressure, maximum dP/dt, and arterial pressure were significantly decreased and left ventricular end-diastolic pressure was significantly increased in the ligation group compared with sham controls. Growth hormone treatment increased left ventricular systolic pressure (p < 0.05) and dP/dt (p < 0.05) and reduced left ventricular end-diastolic pressure (p < 0.05), significantly in the ligated rats. In sham rats, growth hormone tended to decrease arterial pressure but did not alter ventricular contractility. Neither ligation nor growth hormone significantly altered heart rate and right atrial pressure. These results suggest that growth hormone treatment may improve cardiac function by increasing myocardial contractility in cardiac dysfunction or heart failure.

Absence of WAF1 mutations in a variety of human malignancies

A newly cloned gene named wild-type p53-activated fragment 1 (WAF1; also known as p21, Pic-1, Cip-1, or SDI1) is directly regulated by p53 and can itself suppress tumor cell growth in culture. Induction of expression of WAF1 may be an important means by which cells with DNA injury arrest their growth to repair DNA or undergo apoptosis. Based on the hypothesis that mutations of this gene may play a role in carcinogenesis, we have studied 351 DNAs from 14 kinds of malignancies, as well as 36 human transformed cell lines, for alterations of WAF1 gene by single-strand conformation polymorphism analysis of polymerase chain reaction amplification of the DNA coding region of the WAF1 gene. No abnormal band shifts of WAF1 were noted in any of the samples or cell lines, but three major variants in exons 2 and 3 of the gene were found that are consistent with the existence of two different DNA polymorphisms. Sequence analysis of the amplified products producing these three variants in each exon from normal DNAs confirmed the presence of the polymorphisms in the WAF1 gene. Of 290 selected tumor samples previously evaluated for p53 mutations by single-strand conformation polymorphism, 90% had no detectable p53 alterations. In summary, mutations within the coding portion of the WAF1 gene were undetectable in a large series of human tumors, many of which had a normal p53 gene. This suggests that WAF1 alterations are generally caused indirectly, through p53 mutations rather than through intragenic mutation of the WAF1 itself.