Estudio comparativo de algunas características físico-químicas y biológicas del Embalse de El Peñol (Nare)

El presente trabajo se realizó en el Embalse de El Peñol, propiedad de Empresas Públicas de Medellín. Se hizo con el fin de estudiar las condiciones tanto físico-químicas como biológicas en las cuales se encontraba el embalse y para determinar qué cambios se observaban en dichos parámetros a lo largo de un año de estudio. Los muestreos se realizaron cada 15 días, desde marzo 24 de 1973 a marzo 16 de 1974. Desde el punto de vista biológico, el dato más interesante fue el hecho de presentarse un crecimiento masivo o auge de fitoplancton en solo una época del año. En las zonas templadas estos crecimientos corresponden a dos épocas del año, donde el factor determinante es la temperatura. En este estudio, el crecimiento aparentemente se debe a cambios en la concentración de ortofosfatos a lo largo del año, pero indirectamente son los períodos de precipitación en esta zona. Estos podrían determinar cambios en concentración de iones en el agua, lo cual conlleva a cambios en el crecimiento de las poblaciones planctónicas del embalse. Además de los fosfatos, otros factores están aparentemente actuando como limitantes para las poblaciones del fitoplancton, pero sus relaciones con estas no fueron tan estrechas como con fosfatos. 

Forgiveness and armed conflict in a Colombian Caribbean region: Differences between genders

The forgiveness within the framework of social-political conflict is a factor that affects the coexistence and welfare. In the Colombian Caribbean, there are a significant number of people who have been victims of land dispossession and/or forced displacement.

The aim of this study is to compare the forgiveness ability between men and women who have been displaced and are in the process of lands restitutions. Displaced and in restitutions process people were participated (n = 38), which 20 of them were women and 18 were men (Mean = 57.81; SD = 13.86). The CAPER Scale, was administered. A cross sectional and comparative design was carried out. The comparison was performed using a t-test for independent samples (Table 1).

Conclusions

A greater tendency was observed in women for forgiveness himself, noneless a statistically significant gender difference was not identified. It was a greater tendency in men toward forgiveness to others, however there are no statistical differences between the two groups. In forgiveness situations, a similar trend is evident in gender. As for beliefs, it was observed that men scored higher, this allowed statistically significant differences were observed [F (1, 38) = 6.271; P > 0.05].

Table 1Means and SD – Caper Scale1. Women; 2. MennMeanSDStandard error of meanForgiveness himself12028.004.8991.09521826.004.2290.997Forgiveness to others12028.355.4021.20821829.114.1290.973Forgiveness situations12028.005.0161.12221828.003.7570.886Beliefs12011.802.8210.63121813.331.1880.280

Disclosure of interest

The authors have not supplied their declaration of competing interest.

SLC6A15, a novel stress vulnerability candidate, modulates anxiety and depressive-like behavior: involvement of the glutamatergic system

Major depression is a multifactorial disease, involving both environmental and genetic risk factors. Recently, SLC6A15 - a neutral amino acid transporter mainly expressed in neurons - was proposed as a new candidate gene for major depression and stress vulnerability. Risk allele carriers for a single nucleotide polymorphism (SNP) in a SLC6A15 regulatory region display altered hippocampal volume, glutamate levels, and hypothalamus-pituitary-adrenal axis activity, all markers associated with major depression. Despite this genetic link between SLC6A15 and depression, its functional role with regard to the development and maintenance of depressive disorder is still unclear. The aim of the current study was therefore to characterize the role of mouse slc6a15 in modulating brain function and behavior, especially in relation to stress as a key risk factor for the development of mood disorders. We investigated the effects of slc6a15 manipulation using two mouse models, a conventional slc6a15 knock-out mouse line (SLC-KO) and a virus-mediated hippocampal slc6a15 overexpression (SLC-OE) model. Mice were tested under basal conditions and following chronic social stress. We found that SLC-KO animals displayed a similar behavioral profile to wild-type littermates (SLC-WT) under basal conditions. Interestingly, following chronic social stress SLC-KO animals showed lower levels of anxiety- and depressive-like behavior compared to stressed WT littermates. In support of these findings, SLC-OE animals displayed increased anxiety-like behavior already under basal condition. We also provide evidence that GluR1 expression in the dentate gyrus, but not GluR2 or NR1, are regulated by slc6a15 expression, and may contribute to the difference in stress responsiveness observed between SLC-KO and SLC-WT animals. Taken together, our data demonstrate that slc6a15 plays a role in modulating emotional behavior, possibly mediated by its impact on glutamatergic neurotransmission.

Systemic lupus erythematosus in three ethnic groups. XX. Damage as a predictor of further damage

OBJECTIVE

To examine the predictors of damage in a multiethnic cohort of systemic lupus erythematosus (SLE) patients with a specific focus on damage at baseline.

PATIENTS AND METHODS

SLE patients from a multiethnic US (Hispanic, African-American and Caucasian) cohort (LUMINA: Lupus in Minority populations, Nature versus nurture) were included if they had > or =6 months of follow-up in the cohort. Damage was measured with the Systemic Lupus International Collaborating Clinics (SLICC) Damage Index (SDI). The dependent variable was the change in SDI score between study visits. Predictors were from the preceding visit. Variables known to affect damage accrual in SLE were included in the analyses.

RESULTS

Three hundred and fifty-two patients (82 Hispanics, 153 African-Americans and 117 Caucasians) representing 1795 patient visits were included. Previous damage was found to be a significant predictor of subsequent damage accrual (P < 0.0001). Other variables predictive of subsequent damage accrual were disease activity (P < 0.0001), older age (P = 0.041) and use of corticosteroids (P = 0.0048).

CONCLUSIONS

Once damage occurs in SLE, further damage is expected to occur. This is more likely to be the case if disease activity persists. These data have clinical implications for the management of SLE patients.

5'-p-Fluorosulfonylbenzoyl adenosine inhibits progesterone synthesis in human placental mitochondria

The human placental mitochondria have an ATP-diphosphohydrolase (apyrase) activity. In this paper we characterized the effect of 5'-p-fluorosulfonylbenzoyl adenosine (FSBA) on placental apyrase, and its repercussion on progesterone synthesis and oxygen consumption. Apyrase activity was inhibited by FSBA. Nucleosides tri- and diphosphates protected against FSBA inactivation, but divalent cations did not, indicating that FSBA attaches itself to an ATP-binding site of apyrase. In mitochondria, the inactivation of apyrase by FSBA was associated with inhibition of progesterone synthesis. Also, the oxygen consumption induced by ATP but not by ADP, was inhibited, clearly showing that FSBA exclusively inactivated the apyrase in human placental mitochondria. It is concluded that the apyrase activity is closely related to progesterone synthesis, probably associated with the cholesterol transport between mitochondrial membranes.

A preliminary study of forensic entomology in Medellín, Colombia

This is the first report of an ongoing study of insect succession on carrion carried out in Medellín, Colombia, using pigs (Sus scrofa) as a model to determine the insect sequence over 207 days. During this period, 2314 insects belonging to the following orders and families were collected: Diptera: Calliphoridae, Muscidae, Piophilidae, Sarcophagidae, Syrphidae, Otitidae; Hymenoptera: Apidae, Formicidae, Halictidae, Mutilidae, Vespidae; Coleoptera: Staphylinidae, Histeridae, Carabidae, Scarabaeidae, Silphidae, Dermestidae, Cleridae, Nitidulidae; Dermaptera: Forficulidae; Hemyptera: Gelastocoridae, Coreidae; Lepidoptera: Hesperiidae. Five decomposition stages were observed (fresh, bloated, active decay, advanced decay, and dry remains) and four insect ecological categories (necrophagous, predators, omnivorous, and incidental). During the fresh stage, the first insects that appeared were flies of the families Sarcophagidae and Muscidae and specimens of Formicidae (Hymenoptera). During the bloated period, species of Calliphoridae (Diptera) were predominant and the first to oviposit. During the third and fourth stages (active decay and advanced decay), the most abundant families were Calliphoridae and Muscidae, although Staphilinidae (Coleoptera) also stood out. During the last stage (dry remains), the dominant family was Formicidae (Hymenoptera) followed by Dermestidae (Coleoptera) with a large number of immature insects.

Mitogenic action of tumour necrosis factor-alpha and interleukin-8 on explants of human duodenal mucosa

Our aim is to examine whether tumour necrosis factor-alpha (TNF-alpha) and interleukin affect the mitotic activity in explants of human duodenal mucosa and to estimate the release of cytokines from explants incubated with TNF-alpha. Biopsy specimens of normal duodenal mucosa were taken from 19 subjects that underwent upper endoscopy for investigation of dyspeptic symptoms or chronic gastrointestinal bleeding. The specimens were processed following guidelines for organ culture technique. Paired biopsy specimens from 12 subjects were cultured for 23 h to achieve steady state and thereafter the explants were incubated 25 h with 10(-13)-10(-9) M of TNF-alpha or IL-8. Mitoses were arrested in the metaphase by adding vincristine sulphate for the last three hours. The explants were then fixed and processed for microdissection. Fifteen crypts were microdissected and the total number of metaphases was determined using the whole crypt as reference volume. The number of metaphases per crypt was also estimated in explants incubated with 10(-10) M TNF-alpha in the presence of anti-IL-8 antibodies. Additional duodenal explants from seven subjects were incubated with 10(-10) M TNF-alpha for 25 h. Thereafter the release of IL-1-beta, IL-6, IL-8 and interferon gamma (IFN-gamma) into the culture medium was measured by enzyme immunoassay and expressed as pg/mg protein. TNF-alpha and IL-8 significantly increased the number of metaphases/crypts (P<0.0001). The addition of anti-IL-8 slightly reduced the number of metaphases/crypt compared to the values observed in the explants incubated with 10(-10) M TNF-alpha alone (P<0.0001). The number of metaphases/crypt in the explants incubated with 10(-10) M TNF-alpha in the presence of anti-IL-8 antibodies was, however, markedly and significantly higher than that of the controls (P<0.000). TNF-alpha induced the release of IL-8 (P<0.01) and IL-6 (P<0.05) from the duodenal explants. TNF-alpha and IL-8 are potent mitogens to human small intestinal crypts. The mitogenic action of TNF-alpha is primarily a direct effect of the cytokine and only to a minor extent mediated by a secondary production of IL-8 in the duodenal explant. Our findings indicate that TNF-alpha and IL-8 may participate in the regulation of cell proliferation in the human small intestinal epithelium.

Interleukin-1, interleukin-8, tumour necrosis factor alpha and interferon gamma stimulate DNA synthesis but have no effect on apoptosis in small-intestinal cell lines

OBJECTIVES

Cytokines stimulate lymphocyte cell proliferation and affect cell division in several other cell types. Helicobacter pylori-induced gastritis and coeliac disease are characterized by an increased cell proliferation in association with an increased production of proinflammatory cytokines, which could contribute to these cell kinetic changes. Our aim is to examine in vitro whether cytokines usually present in the gastrointestinal mucosa affect DNA synthesis and apoptosis in a rat and a human small-intestinal cell line.

METHODS

IEC-6 and FHs-74 cells were incubated for 24 h with 10(-13)-10(-9) M of tumour necrosis factor alpha (TNF-alpha), interleukin-1beta (IL-1beta), interleukin-2 (IL-2), interleukin-6 (IL-6), interleukin-8 (IL-8), transforming growth factor-beta (TGF-beta) and interferon gamma (IFN-gamma). IEC-6 cells were also incubated with 10(-13)-10(-9) M of interleukin-1alpha (IL-1alpha) and 10(-8) M of interleukin-1 receptor antagonist (IL-1ra). The cells were labelled with 3H-methyl thymidine for the final 4 hours, and then processed for autoradiography. DNA synthesis was evaluated by the labelling index (LI%). Apoptosis was evaluated in IEC-6 cells by changes in membrane lipid asymmetry using annexin-V binding to externalized phosphatidylserine (flow cytometry) and by estimating the caspase activity.

RESULTS

TNF-alpha, IL-1beta, IL-8 and IFN-gamma significantly and markedly increased the LI, even at low concentrations (P< 0.0001), in both IEC-6 and FHs-74 cells, as did IL-1alpha in IEC-6 cells. TGF-beta significantly reduced the LI in both cell lines (P< 0.0001), whereas IL-2, IL-6 and IL-1ra did not affect DNA synthesis significantly. None of IL-1beta, IL-8, TNF-alpha or IFN-gamma affected apoptosis in IEC-6 cells.

CONCLUSION

TNF-alpha, IL-1alpha, IL-1beta, IL-8 and IFN-gamma stimulated DNA synthesis in a human and a rat small-intestinal cell line. The cytokines exert their mitogenic action directly on the intestinal cells via specific receptors. Our findings indicate that pro-inflammatory cytokines may participate in the regulation of the gastrointestinal epithelial cell proliferation in health and disease.

Enteroscopy as a tool for diagnosing gastrointestinal bleeding requiring blood transfusion

Iron-deficiency anemia secondary to gastrointestinal blood loss is a common cause of hospitalization. In many cases, the bleeding site cannot be defined despite thorough routine examination of the gastrointestinal tract. The aim of this study was to evaluate push enteroscopy as a diagnostic tool in patients with severe anemia, secondary to recurrent gastrointestinal bleeding, that required management by transfusion. Thirty-five consecutive push enteroscopy investigations were performed in 1998 and 1999 on 25 patients (15 men, 10 women). Mean age was 57 +/- 16 years (range, 33-83). All patients had received blood transfusions because of pronounced anemia secondary to gastrointestinal bleeding. Before push enteroscopy, all patients had been investigated with esophagogastroduodenoscopy, colonoscopy, and small-bowel radiography using the double contrast technique; no bleeding site was found. In addition, 10 of 25 patients had been investigated beforehand with 99mTc-labelled red blood cell scintigraphy, and 5 of 25 with scintigraphy for Meckel diverticulum. Two patients were also investigated with angiography before the push enteroscopy, and in six patients an additional total intraoperative enteroscopy was performed, preceded by a new colonoscopy, esophagogastroduodenoscopy, and push enteroscopy. A bleeding site was disclosed in 15 of 25 (60%) patients. In 7 of 25 patients (28%) the bleeding site was found in the stomach or esophagus. even though the patients had undergone one or two esophagogastroduodenoscopies earlier with normal findings. Total intraoperative enteroscopy identified a bleeding site in four of six (67%) patients studied. Two patients had bleeding hemangiomas that were resected surgically. Two patients had small intestinal adenomas, one with adenocarcinoma in situ. Push enteroscopy performed with an overtube inserted under fluoroscopic guidance is an important diagnostic tool in patients in whom conventional examinations do not disclose bleeding sites. Interestingly, 28% of patients had bleeding within reach of the gastroscope, indicating that a new upper endoscopy should be recommended before push enteroscopy is performed. When no positive findings are seen on push enteroscopy and the patient is affected by severe, recurrent iron-deficiency anemia, total intraoperative enteroscopy should be considered.

Helicobacter pylori stimulates DNA synthesis in a small intestinal cell line in vitro

BACKGROUND

Helicobacter pylori, which causes gastritis and peptic ulcer, seems to be an important factor in the pathogenesis of gastric cancer and MALT lymphoma. Thus our aim was to examine whether H. pylori influences DNA synthesis in epithelial cells in vitro.

METHODS

Sonicated and water extracts of H. pylori (cytotoxic strains NCTC 11637, 88-23 and A5, and a noncytotoxic isogenic mutant of A5, A5 vac A) were diluted to a final concentration of 1/1,000, 1/100, 1/50 and 1/10. Water extracts of Escherichia coli were used as reference. IEC-6 cells were incubated during 24 h with fragments of H. pylori or extracts of the concentrations described above. The cells were labeled with 3H-methylthymidine for 4 h and processed for autoradiography. DNA synthesis was evaluated by the labeling index (LI).

RESULTS

The LI% of controls was 15.6 +/- 5.1%. All the water extracts and sonicated strains of H. pylori increased the LI% in a dose-dependent manner (p < 0.001). The highest concentrations of the sonicated strains tended to reduce the LI%, although these values were still higher than those of the control group. The water extracts of E. coli increased the LI% in a dose-dependent manner (p < 0.0001).

CONCLUSION

H. pylori stimulates DNA synthesis in epithelial cells in vitro, but no association was found with the presence of cytotoxin production. Our results suggest that hitherto unknown components of H. pylori may contribute to the increase in cell proliferation observed in gastritis and to the development of MALT lymphoma and gastric cancer.

40- to 100-kD protein(s) of Helicobacter pylori stimulate DNA synthesis in epithelial cell lines without affecting apoptosis

BACKGROUND

Previous in vitro studies have demonstrated that water extracts and sonicates of Helicobacter pylori increase DNA synthesis in a small intestinal epithelial cell line. The aim of this study was to identify mitogenic factor(s) in a water extract of a H. pylori strain and to examine their effects on DNA synthesis and apoptosis in vitro.

METHODS

IEC-6 and FHs 74 cells were incubated for 24 h with different dilutions of a water extract of H. pylori (cytotoxic strain 88-23) or with 6 protein fractions obtained by gel filtration. Cells were labeled with tritiated thymidine and processed for autoradiography. DNA synthesis was evaluated by the labeling index (LI%). The proportion of IEC-6 cells undergoing apoptosis and/or necrosis was evaluated by flow cytometry using fluorescein isothiocyanate (FITC)-labeled annexin-V and propidium iodide. In vitro caspase activity was also determined as an alternative method for detection of apoptosis.

RESULTS

The water extract of H. pylori 88-23 markedly increased DNA synthesis in both epithelial cell lines (p < 0.01). A marked stimulation of DNA synthesis was also observed in IEC-6 cells incubated with fraction II- containing proteins of a molecular weight ranging between 40 and 100 kD (p < 0.01). A lesser stimulation of DNA synthesis was observed in cells incubated with higher concentrations of the other protein fractions (p < 0.01). Neither the water extract of H. pylori 88-23 nor the protein fraction II (40-100 kD) induced apoptosis in IEC-6 cells.

CONCLUSION

A water extract of H. pylori 88-23 and a protein fraction containing proteins with molecular weights of 40-100 kD stimulate DNA synthesis in a rat and human small intestinal cell line. Apoptosis was unaffected by the water extract and by protein fraction II, which indicate that the H. pylori-derived mitogen(s) have the capacity to directly enhance epithelial cell proliferation in vitro.

Endogenous prostaglandins are physiological regulators of endocrine cells in the gastroduodenal mucosa of the rat

BACKGROUND/AIM

To investigate whether endogenous prostaglandins participate in the regulation of the gastrointestinal endocrine cell system.

METHODS

Sprague-Dawley rats were treated with 1 mg/kg indomethacin subcutaneously or indomethacin subcutaneously and 500 microg/kg oral prostaglandin E2 or solvents for 2 months. Endocrine cells were visualized by using immunohistochemistry and by the Sevier-Munger silver stain on specimens from the gastroduodenal mucosa, and their total volume was estimated, using standard stereological methods. Plasma and gastrointestinal tissue concentrations of regulatory peptides were analyzed by radioimmunoassay.

RESULTS

Fundic mucosa. The total volume of cells stained with the Sevier-Munger silver stain (enterochromaffin-like) was increased by indomethacin, but reduced by the administration of prostaglandin E2 (P < 0.05 vs. indomethacin). Indomethacin increased the total volume of somatostatin-immunoreactive. Similarly, rats given indomethacin and prostaglandin E2 had higher values than controls. Indomethacin increased the tissue concentration of somatostatin in the gastric fundus whereas prostaglandin E2 prevented such changes (P < 0.05 vs. indomethacin). Antral mucosa. The total volume of serotonin-immunoreactive cells was reduced by indomethacin, but increased by prostaglandin E2 (P < 0.05 vs. controls and indomethacin, respectively). Duodenal mucosa. The total volume of somatostatin-immunoreactive cells was reduced in the rats given indomethacin and prostaglandin E2 (P < 0.05 vs. controls and indomethacin). Indomethacin reduced and simultaneous administration of prostaglandin E2 increased the total volume of CCK-immunoreactive cells (P < 0.05 vs. controls and indomethacin). Indomethacin reduced the total volume of serotonin-immunoreactive cells whereas the simultaneous administration of PGE2 comparatively increased their total volumes (P < 0.05 vs. indomethacin), although they were still lower than the control values. The total volume of GIP-immunoreactive cells was slightly increased in the rats given both indomethacin and indomethacin + prostaglandin E2. The tissue concentration of somatostatin in the duodenum was reduced in rats given indometacin and prostaglandin E2 (P < 0.05 vs. controls and indomethacin).

CONCLUSION

Endogenous prostaglandins, particularly prostaglandin E2, regulate CCK-, enterochromaffin-like-, somatostatin-, GIP- and enterochromaffin cells in the gastroduodenal mucosa of the rat.

A novel ATP-diphosphohydrolase from human term placental mitochondria

This report describes an ATP-diphosphohydrolase activity associated with the inner membrane of human term placental mitochondria. An enriched fraction containing 30 per cent of the total protein and 80 per cent of the total ATP-diphosphohydrolase activity was obtained from submitochondrial particles. ATP-diphosphohydrolase activity was characterized in this fraction. The enzyme had a pH optimum of 8 and catalysed the hydrolysis of triphospho- and diphosphonucleosides other than ATP or ADP. Pyrophosphate was also hydrolysed, but AMP or other monoester phosphates were not. The activity of ATP-diphosphohydrolase was dependent on Mg(2 + ), Ca(2 + )or Mn(2 + )and the enzyme substrate was the cation-nucleotide complex. An excess of free cation produced inhibition.ATP-diphosphohydrolase activity was stimulated at micromolar concentrations of calcium or magnesium in the presence of La-PPi. Negative cooperativity kinetics was observed with all substrates tested. The V(max)ranged from 150 to 300nmol of Pi released/mg/min. The [S](0.5)for nucleotides was 1-10m m and 182m m for PPi. The enzyme was inhibited by orthovanadate, but not by l -phenylalanine, oligomycin, sodium azide, P(1),P(5)-di(adenosine-5')pentaphosphate or sodium fluoride.The experimental evidence showing absence of inhibition by sodium azide and sodium fluoride, hydrolysis of pyrophosphate but not of monoester phosphates, and negative cooperativity suggested that this enzyme was a novel ATP-diphosphohydrolase.

Butyrate inhibits and Escherichia coli-derived mitogen(s) stimulate DNA synthesis in human hepatocytes in vitro

Bacterial constituents and products of the bacterial metabolism pass from the gut lumen to the portal vein and may influence the homeostasis of the liver. Our aim is to examine whether DNA synthesis of human hepatocyte cell lines is affected by constituents of Escherichia coli species as well as by intracolonic products of bacterial fermentation that reach the liver via the portal vein. Supernatant solutions and bacterial cell fractions (containing either whole dead bacteria, cell walls, cytosol or non-soluble intracellular components) of E. coli K12 and of E. coli species from rat fecal flora were separated by multi-step centrifugation, French press, and microfiltration. The supernatant solution and the cell fractions were incubated with a human hepatoma cell line (Hep-G2) and with a cell line derived from non-malignant human liver cells (Chang cells) for 24 h. The cells were labeled with tritiated thymidine before processing to autoradiography. DNA synthesis was estimated by the labeling index (LI%). DNA synthesis was also estimated following incubation of Hep-G2 cells with short chain fatty acids (acetic, propionic, butyric and succinic acid), acetaldehyde, and ammonium chloride. Epidermal growth factor and a water extract of Helicobacter pylori were used as references. The fractions of E. coli from rat fecal flora containing cytosol and non-soluble intracellular components significantly increased the labeling index in both Hep-G2 and Chang cells (p < 0.05). In addition, the supernatant solution significantly increased the LI in Chang cells (p < 0.05). Epidermal growth factor increased the LI of Hep-G2 cells dose-dependently (p < 0.05). Butyric acid reduced DNA synthesis at 10(-4) M (p < 0.05). The highest doses of acetaldehyde were cytotoxic and reduced the LI. Escherichia coli species contain mitogenic factors to human hepatocytes. The mitogen(s) are present in the supernatant solution, in the cytosol and in non-soluble intracellular components. Butyrate, which is a product of bacterial fermentation of colonic substrates inhibit DNA synthesis in the hepatocyte cell lines. Our findings suggest that soluble mitogen(s) that diffuse from the microorganism to the outer environment, intracellular bacterial constituents, and products of the bacterial metabolism that reach the liver via the portal vein may influence the cell kinetic steady-state of hepatic cells.

Differences in cholesterol incorporation into mitochondria from hepatoma AS-30D and human term placenta

Cholesterol transport for steroidogenesis in the human placental mitochondria is an enigma as, contrary to other steroidogenic tissues, the human placenta does not express steroidogenic acute regulatory protein (StAR), a protein known to be required for efficient utilization of cholesterol by adrenal and gonadal mitochondria. These observations suggest the possibility that cholesterol transport in human placental mitochondria involves a similar system to that present in other non-steroidogenic tissues. We studied cholesterol incorporation into mitochondria isolated from AS-30D hepatoma cells and the human placenta. Mitochondria from both sources incorporated cholesterol in vitro. There were no differences in cholesterol incorporation into hepatoma mitochondria treated with or without trypsin. In contrast, the human placental mitochondria treated with trypsin did not incorporate exogenous cholesterol. The presence of ATP increased the uptake of cholesterol by human placental mitochondria. This increase was inhibited by vanadate. These results suggest that cholesterol incorporation into human placental mitochondria is mediated by protein(s).

In vitro aging of Helicobacter pylori: changes in morphology, intracellular composition and surface properties

BACKGROUND

During the conversion from the bacillary into the coccoid form, Helicobacter pylori organisms are known to change extensively. The aim of this study was to determine some of the changes that occur regarding morphology, intracellular composition and surface properties during the aging of bacteria in vitro.

MATERIALS AND METHODS

H. pylori from agar plate cultures of different ages was used in this study. The intracellular composition of the two morphological forms of the bacteria was tested by density centrifugation, DNA extraction and quantitative OD, mRNA and ATP measurements. Immunoblotting was used to observe changes in secreted/superficial protein patterns, and hydrophobicity measurements were used to observe changes in surface properties.

RESULTS

All bacillary H. pylori organisms changed morphology gradually over 10 days of culture. Rods had a higher density than cocci; bacteria stored in PBS had the highest density and bacteria stored in water had the lowest. The quantitative DNA, RNA and ATP content were reduced in the aging bacteria. Fewer immunogenic proteins were expressed, and an increased surface hydrophobicity was observed in the older cultures.

CONCLUSION

This study highlights several aspects of H. pylori aging in vitro and shows some of the differences that exist between bacillary and coccoid forms. This information is important for understanding the transmission and survival of H. pylori outside the human host, as the degradative changes in the intracellular composition and the surface properties shown here point to dead bacteria, and not to a viable but nonculturable form.

Presence of two enzymes, different from the F1F0-ATPase, hydrolyzing nucleotides in human term placental mitochondria

The hydrolysis of ATP, ADP or GTP was characterized in mitochondria and submitochondrial particles since a tightly-bound ATPase associated with the inner mitochondrial membrane from the human placenta has been described. Submitochondrial particles, which are basically inner membranes, were used to define the location of this enzyme. Mitochondria treated with trypsin and specific inhibitors were also used. The oxygen consumption stimulated by ATP or ADP was 100% inhibited in intact mitochondria by low concentrations of oligomycin (0.5 microgram/mg) or venturicidine (0.1 microgram/mg), while the hydrolysis of ATP or ADP was insensitive to higher concentrations of these inhibitors but it was inhibited by vanadate. Oligomycin or venturicidine showed a different inhibition pattern in intact mitochondria in relation to the hydrolysis of ATP, ADP or GTP. When submitochondrial particles were isolated from mitochondria incubated with oligomycin or venturicidine, no further inhibition of the nucleotide hydrolysis was observed, contrasting with the partial inhibition observed in the control. By incubating the placental mitochondria with trypsin, a large fraction of the hydrolysis of nucleotides was eliminated. In submitochondrial particles obtained from mitochondria treated with trypsin or trypsin plus oligomycin, the hydrolysis of ATP was 100% sensitive to oligomycin at low concentrations, resembling the oxygen consumption; however, this preparation still showed some ADP hydrolysis. Native gel electrophoresis showed two bands hydrolyzing ADP, suggesting at least two enzymes involved in the hydrolysis of nucleotides, besides the F1F0-ATPase. It is concluded that human placental mitochondria possesses ADPase and ATP-diphosphohydrolase activities (247).

Lipopolysaccharide of Escherichia coli, polyamines, and acetic acid stimulate cell proliferation in intestinal epithelial cells

Our aim was to examine whether lipopolysaccharide of Escherichia coli, polyamines of dietetic and/or bacterial origin, and products of the bacterial metabolism influence cell proliferation in epithelial cells from the colon and small intestine. Lipopolysaccharide of Escherichia coli 0111:B4 was incubated with cultures from human colonic mucosa. The mitoses were arrested with Vincristine and the total number of metaphases per crypt was counted. In addition, lipopolysaccharide was incubated with a human colonic epithelial cell line from adenocarcinoma (LS-123 cells) and with a nontransformed small intestinal cell line from germ-free rats (IEC-6 cells) for 24 h. In the last 4 h, the cells were labeled with tritiated thymidine. The cells were incubated with putrescine, cadaverine, and spermidine at 10(-11)-10(-3) M and with acetic acid (10(-5)-10(-1) M), acetaldehyde (10(-10)-10(-4) M) and ammonium chloride (1-20 mM). Lipopolysaccharide of Escherichia coli increased the number of arrested metaphases in human colonic crypts and DNA synthesis in L-123 and IEC-6 cells (P < 0.001). All polyamines increased DNA synthesis in the colonic and small intestinal cell lines, the effects being more marked for putrescine (P < 0.001). The higher concentrations of acetic acid increased DNA synthesis in both epithelial cell lines (P < 0.001). Acetaldehyde slightly decreased DNA synthesis in LS-123 cells at cytotoxic concentrations. Ammonium chloride did not significantly affect DNA synthesis. The final concentration of nonionized ammonia was less than 3%. It is concluded that lipopolysaccharides of Escherichia coli and intraluminal factors derived from microorganisms increase cell proliferation in human colonic crypts and intestinal epithelial cell lines.

Cancer-associated strains of Helicobacter pylori stimulate DNA synthesis in IEC-6 cells

OBJECTIVE

To determine whether water extracts of Helicobacter pylori strains, which express CagA, can influence DNA synthesis in untransformed intestinal epithelial cells in vitro.

DESIGN

We used water extracts produced from H. pylori strains (A, B, C), collected from gastric mucosa of gastric cancer patients. Strain A was CagA+/VacA+ whereas strains B and C were CagA+/VacA-. Water extracts from Helicobacter mustelae and Escherichia coli were used as controls.

METHODS

IEC-6 cells (small intestinal epithelial cell line from germ-free rats) were incubated with various concentrations of the bacterial extracts for 24 h. The cells were labelled with [3H]methylthymidine for 4 h and thereafter processed for autoradiography. DNA synthesis was evaluated by the labelling index (LI%).

RESULTS

Water extracts from CagA-positive strains of H. pylori, with or without the capacity to produce vacuolating toxins, increased the LI in a dose-related manner (P < 0.05). The water extracts of E. coli significantly increased the LI (P < 0.001), whereas the water extracts of H. mustelae did not affect DNA synthesis.

CONCLUSIONS

Cancer-associated, CagA-positive strains of H. pylori stimulate DNA synthesis in epithelial cells in vitro, independently of their ability to produce VacA toxin. Our findings suggest that unknown mitogenic components of H. pylori may contribute to the increased cell proliferation observed in the histological stages preceding gastric cancer.

Serotonin and neuroendocrine peptides influence DNA synthesis in rat and human small intestinal cells in vitro

Animal studies suggest a mediator role for neuroendocrine peptides and amines in regulating cell proliferation in the gastrointestinal epithelium. Our aim was to examine the effect of serotonin and selected gastrointestinal peptides on DNA synthesis in a rat and human small intestinal cell line in vitro. IEC-6 and FHs-74 cells were incubated with epidermal growth factor (EGF), insulin-like growth factor II, glucagon, substance P, neurokinin A, calcitonin gene-related peptide (GRP, CCGRP), neurotensin and serotonin. The cells were labelled with [methyl-3H] thymidine and processed for autoradiography. DNA synthesis was evaluated by the labelling index. Epidermal growth factor, insulin-like growth factor II, glucagon, and substance P increased the labelling index in a dose-related manner (P < 0.003). In contrast, a significant dose-dependent reduction of the labelling index was observed after administration of serotonin and neurokinin A (P < 0.0001). Neurotensin and CGRP did not affect the labelling index. EGF, insulin-like growth factor II, glucagon, substance P, serotonin and neurokinin A may be important physiological regulators of proliferation, of gastrointestinal cells.

Preparation and hybridization analysis of DNA/RNA from E. coli on microfabricated bioelectronic chips

Escherichia coli were separated from a mixture containing human blood cells by means of dielectrophoresis and then subjected to electronic lysis followed by proteolytic digestion on a single microfabricated bioelectronic chip. An alternating current electric field was used to direct the bacteria to 25 microlocations above individually addressable platinum microelectrodes. The platinum electrodes were 80 microns in diameter and had center-to-center spacings of 200 microns. After the isolation, the bacteria were lysed by a series of high-voltage pulses. The lysate contained a spectrum of nucleic acids including RNA, plasmid DNA, and genomic DNA. The lysate was further examined by electronically enhanced hybridization on separate bioelectronic chips. Dielectrophoretic separation of cells followed by electronic lysis and digestion on an electronically active chip may have potential as a sample preparation process for chip-based hybridization assays in an integrated DNA/RNA analysis system.

Sulphasalazine, olsalazine and sulphapyridine induce mitogenic actions in the rat intestinal epithelium

Our aim was to study the influence of sulphasalazine (SASP), olsalazine (ADS) and sulphapyridine (SP) on the cell kinetics of the intestinal epithelium in conventional rats. Groups of rats were treated with SASP, ADS or SP for 9 days. After an intraperitoneal injection of a metaphase blocker, the rats were killed and the jejunum, ileum and colon were examined in histological sections by means of the cumulative mitotic index (MI), growth fraction and number of cells in crypts and villi. SP increased both the MI in the jejunum, ileum and colon and the number of crypt cells (p < 0.05 vs controls). In contrast, SASP and ADS increased the MI only in the colonic epithelium (p < 0.05 vs controls). The growth fraction was essentially unaffected. Our results suggest that SASP, SP and ADS have a selective compartment-dependent proliferative action on the epithelium of the intestinal tract.

Endogenous prostaglandins and microflora modulate DNA synthesis and neuroendocrine peptides in the rat gastrointestinal tract

BACKGROUND

Previous studies suggest that E2 prostaglandins and the microflora may participate in the regulation of endocrine cells and of gastrointestinal cell kinetics. Our aim is to examine the actions of endogenous prostaglandins and of the microflora on gastrointestinal cell proliferation and tissue levels of neuroendocrine peptides.

METHODS

Germfree and ex-germfree rats were treated with subcutaneous placebo or 1.5 mg/kg indomethacin for 3 days. All rats were labeled with 3H-methyl-thymidine, and biopsy specimens from different parts of the gastrointestinal tract were processed for autoradiography. DNA synthesis was estimated by the labeling index, except in the oxyntic mucosa, where the total number of labeled cells present in 7.5 mm mucosa was used. The concentration of neuroendocrine peptides was determined by radioimmunoassay.

RESULTS

In the germfree rat, indomethacin reduced DNA synthesis in the fundus, duodenum, and proximal jejunum (P < 0.05) and the number of villous cells throughout the small intestine (P < 0.05). Exposure to microflora increased DNA synthesis in the proximal and distal jejunum, ileum, and colon (P < 0.05 versus germfree controls) and the number of crypt cells in the distal small intestine and colon (P < 0.05) and reduced the number of villous cells in the small intestine (P < 0.05) but did not affect tissue concentrations of neuroendocrine peptides. Indomethacin increased the concentration of somatostatin in the stomach, duodenum, and colon of germfree rats (P < 0.001), the concentration of calcitonin gene-related peptide (CGRP) and enteroglucagon in the proximal and distal jejunum and ileum (P < 0.001), and the concentration of glucagon in the colon (P < 0.05). The concentrations of somatostatin, CGRP, and glucagon were lower in indomethacin-treated ex-germfree rats than in indomethacin-treated germfree rats (P < 0.01).

CONCLUSIONS

Indomethacin selectively reduced DNA synthesis in the upper gastrointestinal tract of germfree rats, indicating a basal stimulatory role for endogenous prostaglandins on cell proliferation. Endogenous prostaglandins modulate synthesis or release of gastrointestinal neuroendocrine peptides. Somatostatin may mediate indomethacin-induced reduction of DNA synthesis. The microflora stimulates cell proliferation and influences tissue levels of neuroendocrine peptides in a manner opposite to that of indomethacin.

Indomethacin influences regulatory peptides and increases DNA synthesis in the gastrointestinal tract of the rat

OBJECTIVE

To examine the effect of long-term administration of indomethacin on regulatory peptides and DNA synthesis.

DESIGN

Sprague-Dawley rats were treated with 1 mg/kg indomethacin subcutaneously or indomethacin and 500 micrograms/kg oral prostaglandin E2 or solvents for 2 months before labelling with methyl-3H-thymidine.

METHODS

The labelling index, growth fraction and the number of epithelial cells were determined on autoradiographs of the stomach small intestine and colon. Plasma and gastrointestinal tissue concentrations of regulatory peptides were analysed by radioimmunoassay.

RESULTS

Indomethacin increased the concentration of somatostatin in the gastric fundus and ileum and reduced it in the colon. Prostaglandin E2 reduced the somatostatin concentration in the duodenum and colon. Indomethacin increased the concentration of neurotensin neurokinin A and glucagon in the distal small intestine and reduced the glucagon level in the colon. Prostaglandin E2 prevented such changes. Indomethacin increased DNA synthesis in the small intestine and produced hypoplasia of the villi. These changes were prevented by prostaglandin E2, except for the villous hypoplasia observed in the distal small intestine. Prostaglandin E2 reduced the labelling index in the antrum and colon.

CONCLUSION

Endogenous prostaglandins selectively modulate the synthesis and/or release of regulatory peptides and regulate the outflow of cells from the epithelial surface. Indomethacin induces hypoplasia, which triggers a secondary trophic reaction in the epithelium that may, at least partially, be mediated by regulatory peptides.

Three-dimensional estimation of the glandular volume, and of the number and volume of epithelial cells in two glands from the antral mucosa of five healthy volunteers

Specimens of antral mucosa were taken from five healthy volunteers and processed for microscopic evaluation. Consecutive 50-micron-thick sections were cut to estimate the volume of two antral glands. Two glands in each section were followed throughout by projecting their profiles from two microscopes mounted in parallel. The glandular volume was estimated using Cavalieri's principle. The mean volume of epithelial cells was estimated by systematic random sampling of the sections with an optical disector of known sample volume. The total number of cells per gland was calculated after determination of the volume of the glands and the mean volume of the epithelial cells. The mean volume of the antral glands was 13.6 +/- 1.67.10(6) microns3, whilst the mean volume of the epithelial cells was 1256 +/- 240 microns3. The total number of epithelial cells per gland was 11216 +/- 1104. In conclusion, using stereological methods, the total number of cells as well as the cell volume and the volume of antral glands can be determined in routine biopsy specimens of human stomach provided that the total depth of the mucosa is present in the section.

Brachial plexus injury due to compression: an alternate mechanism of injury: case report and review of the literature

We present a case of a brachial plexus injury due to compression of the nerves from a traumatic hematoma, with no associated bone or vascular injury. The paralysis in this case was not evident for 48 hours after the initial injury, implying that the brachial plexus was not damaged directly. Electromyograms documenting brachial plexopathy were obtained. The mechanism of injury in this case is different from the usual mechanisms of injury in brachial plexus trauma. The majority of brachial plexus injuries are associated with multisystem trauma. The mechanism of injury to the brachial plexus is either from extreme traction on the nerves or direct impact. Downward traction generally results in lesions in the upper cervical nerve roots, whereas upward traction results in lesions of the lower cervical nerve roots, C8 and T1. The usual symptoms of brachial plexus injuries include paralysis of the shoulder, arm, and/or hand with parasthesias and altered sensation. Temperature and color of the limb may be altered because of damage to the autonomic nervous system. The treatment of brachial plexus injuries varies depending on the mechanism and the time the injury is discovered in relation to the inciting trauma. Current treatment includes assessing function with physical examination, preoperative electromyogram, and then repair of viable nerve roots and associated vascular injuries.

Cell kinetic events in early indomethacin-induced gastrointestinal ulcerations in the rat

OBJECTIVE

To follow the sequence of cell kinetic events leading to the development of ulcerations in the gastrointestinal mucosa to better define primary actions of the drug and secondary phenomena mediated by the mucosal regulatory mechanisms.

DESIGN

Sprague-Dawley rats were given 4 mg/kg indomethacin subcutaneously as a single dose and killed 4h later. Additional rats were given three and five doses, twice daily, and were killed at 24h and 48h, respectively. Other groups were treated with indomethacin and oral prostaglandin E2 or placebo. All rats were killed 3h after mitotic arrest with vincristine.

METHODS

Histological sections from the oxyntic mucosa and proximal and distal jejunum were evaluated using a light microscope. The total number of arrested mitoses were counted in 250 microm width area of 30 consequent fields. In addition, the thickness and proliferative zone of the mucosa were determined. The cumulative mitotic index (MI%) and the number of cells in the left column of 30 well oriented crypts and villi were estimated in the proximal and distal small intestine.

RESULTS

The vast majority of rats given five doses of indomethacin developed small intestinal ulcerations and peritonitis and most of them showed haemorrhagic lesions in the oxyntic mucosa. Indomethacin reduced the number of mitotic cells in the oxyntic mucosa after three and five doses compared to controls (P<0.05). In addition, the thickness was significantly reduced in rats given five doses of indomethacin (P<0.05). These changes were prevented by the concomitant administration of prostaglandin E2. The MI% of the jejunal crypts was not affected by indomethacin but the number of villous cells was significantly lower in rats given five doses of indomethacin than in controls (P<0.05). A slight villous hyperplasia was observed in animals given three doses of indomethacin with prostaglandin E2 (P<0.05). The number of crypt cells was unaffected by treatments.

CONCLUSION

Indomethacin reduced cell proliferation in the oxyntic and jejunal epithelium, and increased epithelial cell losses, which are cell kinetic mechanisms leading to development of ulcerations. The regulatory mechanisms that increase DNA synthesis need longer periods of time to be triggered and they were not apparent in this model, in which the marked cell kinetic changes induced by indomethacin produced ulcerations within 48 h.

Prostaglandin E2 modulates serotonin- and gastrin/CCK-immunoreactive cells in the duodenal mucosa of the rat

Groups of Sprague-Dawley rats were given placebo or prostaglandin E2 (PGE2) at 25 or 5,000 micrograms/kg or 15,R,15-methyl-PGE2 (MePGE2) at 5 or 50 micrograms/kg, twice daily, orally, for 1 month. Histological sections from the proximal duodenum were processed for immunohistochemistry and the volume density of immunoreactive endocrine cells was determined using point-counting grids. The surface density of the villous lining was estimated by using a cycloid test system. Thereafter, the total volumes of endocrine cells and the total surface area of the villous lining were calculated after estimating the mucosal volume. The volume density of serotonin-immunoreactive cells was increased in the duodenum of rats given 25 or 5,000 micrograms/kg PGE2 (p < 0.05). The total volume of these cells increased in the animals given 25 micrograms/kg PGE2 (p < 0.05). The total volume of gastrin/CCK-immunoreactive cells was higher in rats given 25 micrograms/kg PGE2 or 50 micrograms/kg MePGE2 than in controls (p < 0.05). The volume density of somatostatin-immunoreactive cells increased in rats given 5 micrograms/kg MePGE2, but the total volumes were not different between the groups. The area of somatostatin-immunoreactive cell profiles was enlarged in the animals given 5,000 micrograms/kg PGE2 (p < 0.05). The mucosal volume was enlarged by prostaglandins. The epithelial thickness increased in rats given the highest doses of PGE2 (p < 0.05). The concentration of motilin-like immunoreactivity increased in the duodenum of rats given 5 micrograms/kg MePGE2 (p < 0.05). We conclude that oral administration of PGE2 for 1 month increased the total volumes of serotonin- and gastrin-CCK-immunoreactive cells and the tissue concentration of motilin-like immunoreactivity, which indicates that prostaglandins modulate endocrine cells in a stable steady-state condition.

Characterization of the F1F0-ATPase and the tightly-bound ATPase activities in submitochondrial particles from human term placenta

In a previous study we demonstrated the existence of a tightly-bound ATPase in the human placental mitochondria (Martínez et al., 1993). The current study characterizes the ATP hydrolysis produced by the F1F0-ATPase and the tightly-bound ATPase in submitochondrial particles from the human term placenta. Both enzymes were not differentiated by pH. Inhibitors were necessary to distinguish the activity of each enzyme. The kinetic of the total ATP hydrolysis fitted into a model of two enzymes. During the characterization, it was observed that the tightly-bound ATPase activity was partially inhibited by vanadate and Mg2+, whereas the F1F0-ATPase was totally inhibited by Mg2+. Different nucleotides were hydrolyzed by the tightly-bound ATPase; the F1F0-ATPase hydrolyzed exclusively ATP. Glucose-6-phosphate, p-nitrophenylphosphate, or pyrophosphate were not hydrolyzed by the F1F0-ATPase, although some hydrolysis was observed with the tightly-bound ATPase. It is concluded that the tightly-bound ATPase activity corresponded to a 5'-nucelotidase, and that the human placental mitochondria could participate in the metabolism of nucleotides.

Immediate and long-term results of balloon mitral commissurotomy for rheumatic mitral stenosis: comparison between Inoue and double-balloon techniques

We examined the immediate results and 2-year follow-up of percutaneous transvenous mitral commissurotomy (PTMC) using the Inoue balloon (IB) and double-balloon (DB) techniques. Short-term comparisons have been described, but long-term comparisons have not been available. PTMC was performed in 208 adult patients with symptomatic mitral stenosis (MS) and mitral valve area (MVA) of 0.94 +/- 0.2 cm2, by use of the IB in 157 (73.4%) and the DB technique in 56 (26.3%). Procedures were performed successfully and without complications in 198 (93%) cases. Adequate mitral dilatation (MVA = 1.6 cm2) without significant regurgitation was obtained in 179 (86%) of 192 patients. The final MVA was 2.0 +/- 0.43 cm2 after IB and 2.06 +/- 0.51 cm2 after DB (not significant). Technical difficulties and complications were more frequent with DB (16% vs 3.8%; p<0.001). Severe mitral regurgitation (grade III to IV) occurred in 4.6% of IB and 4.1% of DB (not significant), whereas grade 1 mitral regurgitation was greater with IB (21% vs 10.2%; p=0.01). A total of 172 patients were monitored an average of 23.8 +/- 10.6 months, with 83% in New York Heart Association functional class 1, echocardiographic MVA of 1.84 +/- 0.44 cm2, and restenosis rate of 22% at 36 months. PTMC is a safe, effective treatment for symptomatic MS. Results of both IB and DB techniques are similar, but the IB is simpler and safer, Long-term clinical improvement is maintained, although the restenosis rate seems to be progressive and related to inadequate immediate results.

Indomethacin inhibits cell proliferation and increases cell losses in rat gastrointestinal epithelium

Gastrointestinal cell proliferation was estimated in histological sections of rats treated with low and high doses of parenteral indomethacin for 3 to 60 days. Mitoses were arrested with vincristine and cells in S phase were labeled with tritiated thymidine. Short-term, low-dose treatments reduced the mitotic activity in the oxyntic and small intestinal epithelium, whereas moderate doses restored the mitotic index and high doses increased the proliferative activity and produced epithelial hyperplasia. Long-term, low-dose treatments increased cell proliferation in the small intestine and reduced the number of villous cells. Indomethacin did not affect the proliferative response elicited by refeeding in the oxyntic mucosa, but the simultaneous administration of prostaglandin E2 analog increased the number of arrested mitoses. The turnover of labeled cells was accelerated by indomethacin, particularly in the small intestine. These findings indicate that prostaglandins are regulators of the cell kinetics of the gastrointestinal epithelium but, at the same time, they disclose the presence of trophic mechanisms that are independent of the synthesis of endogenous prostaglandins.

[Percutaneous transluminal angioplasty with a balloon catheter in native aortic coarctation: long-term experience]

Between August 1988 and October 1993, 19 patients with native aortic coarctation were subjected to transluminal percutaneous balloon angioplasty, 12 of which were men (63.1%) and 7 were women (36.9%), with an average age of 22 +/- 7.7 years (r- 16 to 52), all of whom suffered from arterial hypertension at the time of the procedure, and a systolic pressure of 190 +/- 32.2 mmHg (r- 160 to 240). The gradient of the systolic pressure (GPS) was 77 +/- 0.9 mm, the average diameter of the balloon catheters that were used was 18.3 +/- 1.7 mm (r- 15 to 20). For all the patients, the procedure was carried out under local anesthesia and the usual Seldinger technique. After carrying out the procedure, the GPS as well as the blood pressure dropped to 5.0 +/- 4.1 mmHg and 130 +/- 20.6 mmHg, respectively. In similar manner, the enlargement of the ring displayed an increase of 4.2 +/- 0.9 to 14.1 +/- 1.6 mm. There were no complications in any of the procedures. During the follow-up, 11 patients were catheterized again in a period of 24.7 +/- 12.6 months (r- 10 to 48) with GPS of 5 +/- 2 mmHg. Besides, an increase of 15.4 +/- 1.2 mm in the ring's diameter was observed. In these patients, there was no evidence of the aneurysms at the dilatation site. Of the rest of the patients under control, 17 of whom have been able to maintain normal blood pressure without medical treatment, and only two required low dosages of antihypertensive treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

[Mitral insufficiency after mitral balloon-catheter valvuloplasty: its incidence, predictive factors and prognosis]

From October 1991 to October 1993, a total of 205 patients with rheumatic mitral stenosis (178 female, 27 male, mean age 38 years, range 17-72) underwent percutaneous transvenous mitral commissurotomy (PTMC), 138 with the Inoue balloon and 67 with double balloon-catheter techniques. Mitral regurgitation (MR) was detected in 10% of the cases prior to the procedure, and 37% after PTMC (p < 0.05), grade I in 45 patients (22%), grade II in 24 (12%), grade III in 4 (2%), and grade IV in 3 (1.5%) cases (p = 0.003, 0.002, N.S. and N.S., respectively. In 40% of the total group (83/205) there was no new or worsening MR; in 26.8% of the cases (55/205) new MR appeared (p = 0.004); in 23% (47/205) MR increased one grade (p = 0.002) and in 9.7% (20/205) two or more grades. The comparative incidence of MR was 40.5% (56/138) with the Inoue balloon, and 16.4% (11/67) with the double balloon technique (p = 0.03); the severity of MR was grade I in 27% vs 9% (p = 0.001), grade II in 9.4% vs 6% (p = 0.05), grade III in 2.1% vs 1.5% (N.S.), and grade IV in 2.1% vs 0% (N.S.). Only the presence of commissural calcification and echo-score > 8 points were found as independent predictors of severe MR. In conclusion, mild and moderate MR occur frequently after PTMC, with significantly greater incidence using the Inoue technique. Severe MR following PTMC is much less frequent, and the comparative incidence is somewhat greater with the Inoue balloon, though the difference is not significant.

Microflora modulates endocrine cells in the gastrointestinal mucosa of the rat

BACKGROUND/AIMS

Gastrointestinal peptides and biogenic monoamines participate in the regulation of gastrointestinal functions. The aim of this study was to examine the influence of the microflora on the distribution of endocrine cells and on the release of gastrointestinal peptides.

METHODS

A quantitative morphological study using stereological methods was performed in gastrointestinal sections of conventional and germ-free rats. Tissue and plasma concentrations of peptides were measured.

RESULTS

The total volumes of gastrin- and serotonin-immunoreactive cells were significantly increased in the gastric mucosa of germfree rats (P < 0.05), as well as the total volumes of serotonin- and motilin-immunoreactive cells in the ileum (P < 0.05) and serotonin-immunoreactive cells in the colonic mucosa (P < 0.05). The tissue concentration of somatostatin was significantly higher in the jejunum (P < 0.05) and lower in the ileum of germfree rats than in controls (P < 0.05). Plasma glucagon was significantly increased in germfree rats (P < 0.05). The total volume of the fundic mucosa was enlarged in germfree rats (P < 0.05), whereas the total volume, the mucosal thickness, and the number of crypt cells of the colonic mucosa were significantly reduced in these rats compared with controls (P < 0.05).

CONCLUSIONS

Our findings suggest that the intraluminal microflora influences the release of biologically active peptides and that it participates in the regulation of gastrointestinal endocrine cells and the epithelial structure.

Characterization of Ca2+ transport in Euglena gracilis mitochondria

The present study was designed to establish the characteristics of the Ca2+ fluxes in isolated mitochondria of the protist Euglena gracilis. Uptake of Ca2+ and Sr2+ was supported by succinate and lactate oxidation. Ca2+ influx was slightly inhibited by 5 microM Ruthenium red and completely blocked by La3+ with a half-maximal inhibition attained at 50 microM. The addition of inorganic phosphate induced a 3-fold stimulation of Ca2+ uptake. Ca2+ uptake was inhibited by Mg2+ only in the absence of phosphate. Ca2+ efflux was induced by Na+, Li+ and K+ through a diltiazem-insensitive reaction. Ca2+ release, collapse of membrane potential and swelling were induced by Hg2+ and Cd2+ but not by carboxyatractyloside; cyclosporin A did not prevent the Ca2+ release induced by the heavy metal ions. Ca2+ uptake was achieved in the presence of 3 microM antimycin or 0.1 mM cyanide; this finding indicates that the alternative respiratory chain present in Euglena mitochondria can support this energy-dependent reaction. The data obtained suggest similar pathways, but different regulatory mechanisms, for Ca2+ transport between protist and mammalian mitochondria.

Differential cell kinetics in the ileum and colon of germfree rats

Our aim was to study the cell kinetics and epithelial structure in the ileum and colon of conventional and germfree AGUS rats by means of a classic stathmokinetic technique. A slight hyperplasia was observed in the villi of germfree animals (p < 0.05), associated with a comparatively short cell cycle time. The crypt cell production rate was reduced in the colon of germfree rats (p < 0.05), and their crypts contained fewer cells than those of conventional animals (p < 0.05). It is concluded that intraluminal bacteria influence cell proliferation in the colon. The absence of microflora prolongs the cell cycle time and reduces the proliferative activity in the colonic crypts, which contributes to a steady state that is different from that of conventional animals.

Glutamine supplementation does not prevent small bowel mucosal atrophy after total parenteral nutrition in the rat

Glutamine supplementation to non-lipid parenteral nutrition has been demonstrated to attenuate villus atrophy and increase mucosal DNA content in the rat. This study was performed in order to determine the effects of glutamine supplementation to a balanced TPN mixture (including lipids) on epithelial cell kinetics using autoradiography. Male Sprague-Dawley rats were used. Group 1 (control) received food and an intravenous saline infusion. Group 2 received an intravenous TPN mixture including lipids but without glutamine. The same TPN mixture, glutamine replacing an isonitrogenous amount of non-essential amino acids, was given to Group 3. Animals were fed for 7 days, whereafter blood and intestinal samples were taken 1 h after injection of tritiated thymidine. Microscopy of specimens from proximal jejunum revealed a significant reduction in the number of cells in crypts and villi in both TPN groups (2 and 3) compared to orally fed animals (p < 0.001). Epithelial cell numbers were not significantly different in Group 2 and 3. Similarly, the labelling index (number of labelled cells/number of crypt cells) was not affected by glutamine administration. In plasma, glucagon concentrations in Group 2 (TPN without glutamine) seemed to decrease compared to Group 1 and 3 (p = 0.06). In this study, glutamine supplementation did not affect apithelial atrophy or cell proliferation. It is concluded, that the effects of glutamine on mucosal atrophy and renewal in jejunum may depend on the composition of the TPN mixture supplied during parenteral feeding.

Abnormal colonic microbial function in patients with rheumatoid arthritis

The aim of this study was to examine the microflora-associated characteristics (MACs) of faecal samples of patients with rheumatoid arthritis (RA) and to evaluate the actions of sulphasalazine (SASP) on these MACs. The conversion of cholesterol to coprostanol, the production of urobilinogen, the degradation of faecal tryptic activity (FTA) and of beta-aspartylglycine were measured in faecal samples from 19 patients treated with SASP and 21 patients not treated with this medication. A control group of 21 healthy subjects was sex- and age-matched with the untreated patients. The conversion of cholesterol to coprostanol showed a bimodal distribution. The frequency of high converters in patients without SASP treatment was higher than in healthy subjects (p < 0.05). Treatment with SASP markedly increased the FTA and reduced the urobilinogen values, as compared to the untreated patients (p < 0.05). Beta-aspartylglycine was not found in any faecal samples. The results indicate that patients with RA have an abnormal formation of coprostanol, which is ascribed to alterations in the function of the Eubacteria species. In patients with RA, SASP treatment induces disturbances in the metabolism of the microflora.

Ionophoretic-like properties of ketorolac for calcium

Ketorolac is an analgesic drug known to induce its therapeutic effect by inhibiting prostaglandin synthesis. In this work we introduce the nonsteroidal antialgesic drug as a compound with ionophoretic properties for calcium ions, showing that ketorolac induces mitochondrial Ca++ release. This reaction did not depend on an uncoupler-like action, because the drug does not collapse the internal negative membrane potential nor does it affect oxidative phosphorylation. In addition, it is shown that ketorolac ferries calcium ions into energized liposomes and has a hydrophobic phase with an affinity constant of 4 x 10(-3). The therapeutic action of ketorolac is related to its ionophoretic properties in addition to its well known inhibitory effect on the cyclooxygenase enzyme.

Helicobacter pylori infection, ABO blood group, and effect of misoprostol on gastroduodenal mucosa in NSAID-treated patients with rheumatoid arthritis

Our aim was to investigate the effect of misoprostol on NSAID-induced gastroduodenal mucosal damage in patients with rheumatoid arthritis. The study included 40 patients, and it was designed as a double-blind, placebo-controlled trial. Misoprostol significantly reduced the gastroduodenal mucosal lesions found at endoscopy (P < 0.05) and prevented the development of ulcers. The cumulative incidence of ulcers at four weeks was 5% in the placebo group and 0% in the misoprostol group. The basal and pentagastrin-stimulated acid output as evaluated after 23 days of treatment with misoprostol was not significantly affected. Forty-one percent of the patients had signs of current Helicobacter pylori infection, 33% had positive serology only, and 26% had no evidence of infection. Most of the patients with current infection belonged to blood group O (P < 0.05). Misoprostol treatment did not affect the occurrence of Helicobacter pylori or the rheumatic disease activity. It is concluded that the protective actions of misoprostol on the gastroduodenal mucosa of NSAID-treated patients are largely mediated by mechanisms other than inhibition of acid secretion. The relationship among active Helicobacter pylori infection, blood group O, and peptic ulcer may be helpful to identify a subpopulation of patients taking NSAIDs at risk of developing peptic ulcers.

Functional alterations of the microflora in patients with ulcerative colitis

The aim of the study was to examine microflora-associated characteristics in patients with inactive ulcerative colitis, receiving sulphasalazine, in relation to the spread of the disease. The conversion of cholesterol to coprostanol, the production of urobilinogen, and the degradation of tryptic activity (FTA) and beta-aspartylglycine were measured in faecal samples from patients with proctitis or left-sided or total ulcerative colitis and in age- and sex-matched controls. No significant differences in the results were observed in patients with various degrees of extension of inflammatory bowel disease. However, the coprostanol ratio and the urobilinogen level were lower and the FTA was higher in patients with colitis than in the controls (p < 0.05). Beta-aspartylglycine was not found in any faecal sample. The results indicate that patients with ulcerative colitis taking sulphasalazine have a microflora with abnormal metabolic characteristics.

Contact diode laser microvascular anastomosis

Contact diode laser microvascular anastomosis appears to be a valuable technique for anastomosing small arteries and veins. Significantly less foreign body reaction and markedly decreased operative time has been shown to be a major advantage of using contact diode laser technology. The authors have found that contact diode laser anastomosis can be performed in vessels as small as 1 mm in size using a 200-microns flat tip synthetic sapphire probe. Light microscopy has shown a significant decrease in foreign body reaction at the level of the anastomosis using laser techniques as compared to standard vessel anastomosis with 10-0 nylon sutures. The role of fibronectin and changes in collagen associated with laser anastomosis were also explored. Light microscopic electron-microscopic results as well as biotin-avidin immunoperoxidase fibronectin studies will be discussed.

Small intestinal bacterial overgrowth in patients with rheumatoid arthritis

OBJECTIVES

To examine the microflora of the upper small intestine in patients with seropositive rheumatoid arthritis (RA) using a combination of microbial cultivation and tests for microbial metabolic activity.

METHODS

Twenty five patients with seropositive RA, 12 achlorhydric control subjects, and 11 control subjects with normal gastric acid secretion were investigated. Disease activity was evaluated in the patients with RA by three different indices. Eight (32%) of the patients with RA had hypochlorhydria or achlorhydria. The acid secretory capacity was determined with pentagastrin stimulation. A modified Crosby capsule was used to obtain biopsy specimens and samples of intestinal fluid from the proximal jejunum; aerobic and anaerobic microbial cultivation of mucosal specimens/intestinal fluid was carried out, and gas production and microflora associated characteristics in jejunal fluid were determined. Additionally, a bile acid deconjugation breath test was performed.

RESULTS

Subjects with at least one of the following findings were considered to have bacterial overgrowth: positive bile acid deconjugation test; growth of Enterobacteriaceae; positive gas production; or low tryptic activity. By these criteria half of the patients with RA with hypochlorhydria or achlorhydria and half of the achlorhydric controls had bacterial overgrowth. Thirty five per cent of the patients with RA with normal gastric acid secretion had bacterial overgrowth compared with none of the normal controls. Disease activity indices and rheumatoid factor titres were significantly higher in patients with RA with bacterial overgrowth than in those without.

CONCLUSIONS

A high frequency of small intestinal bacterial overgrowth was found in patients with RA; it was associated with a high disease activity and observed in patients with hypochlorhydria or achlorhydria and in those with normal acid secretion.

[The treatment of severe mitral stenosis by percutaneous transvenous commissurotomy]

In 110 adult selected patients, 87.1% female (average age 38.2 years, range 16-72) with symptomatic, severe mitral stenosis eligible for surgery, we performed balloon catheter transvenous mitral commissurotomy (BCTMC) as alternative treatment. Inoue's catheter was utilized in 80 cases (72.7%), and the double-balloon technique in 30 (27.3%). The procedure was successful in 102 patients (92.7%, 2nd attempt in 5 cases), with optimal results in 96 (87.3%); and it was unsuccessful in one patient for a technical difficulty. Complications occurred in 3 cases due to perforation of a cardiac chamber (2.7%); and 4/106 patients developed severe mitral insufficiency (3.8%). The mitral valve area increased from 1.09 +/- 0.27 to 2.6 +/- 0.87 cm2 (p < 0.0001); the diastolic mitral gradient decreased from 18.9 +/- 5.9 to 3.6 +/- 2.8 mmHg (p < 0.0001); similar reduction was obtained in mean left atrial pressure from 26.2 +/- 6.5 to 12.5 +/- 4.2 mmHg (p < 0.0001), and mean pulmonary artery pressure from 38 +/- 17 to 26.2 +/- 10.4 mmHg (p < 0.005). New mitral insufficiency appeared or increased in more of one grade in 12/106 patients (11.3%), and it was not detectable in 86/106 patients. During long-term follow-up (average 10.4 months, range 5 to 24), all patients (100 cases) improved their functional class (83.1% asymptomatic), and maintained their 2D echocardiographic mitral valve area. In conclusion BCMTC is the treatment of choice for selected cases of acquired symptomatic mitral stenosis, with immediate and long term results comparable to surgical commissurotomy.

[Percutaneous transvenous mitral commissurotomy with a Medi-tech balloon catheter: the initial experience and midterm follow-up]

From Jan-21-91 to Jan-8-92 we performed percutaneous transvenous mitral commissurotomy (PTCM) with a Medi-tech balloon catheter (MBC) in 41 patients bearing mitral stenosis simple o predominant. We utilized an anterograde transseptal approach in order to access the mitral valve, the procedure failed in 5 patients, in 30 of them we used double MBC and single MBC were utilized in 6 patients. Both left ventriculogram and hemodynamic parameters were taken before and after PTCM. Posterior to PTCM an important decrease appeared in the mitral transvalvular gradient from 20.6 +/- 2.7 to 2.4 +/- 1.7 mmHg (p < 0.0001) and an average pressure of pulmonary artery of 46.2 +/- 9.8 to 23.9 +/- 6 mmHg (p < 0.0001), and also the pulmonary arterial resistance from 1178.1 to 557.1 dinas/cm-5/seg. There was an important concomitant increase in mitral valvular area from 0.84 +/- 0.11 to 2.38 +/- 0.08 cm2 (p < 0.0001) and in cardiac rate from 2.7 +/- 0.7 to 2.9 +/- 0.52 L/min (p < 0.001).

COMPLICATIONS

Two female patients developed cardiac tamponade, one of them the procedure was successful, and for the other it was decided to submit her to valvular replacement. Mitral insufficiency was present in three patients; GI/IV in two of them and GII/IV angiographic in one. Another patient presented cerebral thromboembolism with complete recovery within 15 days. Short left to right shunt was detected only in 8 patients being 1.2/1 in 6 of them, 1.3/1 in one and 1.4/1 in other patient. Thirty three uncomplicated were dismissed within a maximum of 48 hours after procedure.(ABSTRACT TRUNCATED AT 250 WORDS)