Intraoperative Patterns of Gastric Microperfusion During Laparoscopic Roux-en-Y Gastric Bypass

Introduction

Visible light spectroscopy (VLS) represents a sensitive, non-invasive method to quantify tissue oxygen levels and detect hypoxemia. The aim of this study was to assess the microperfusion patterns of the gastric pouch during laparoscopic Roux-en-Y gastric bypass (LRYGB) using the VLS technique.

Methods

Twenty patients were enrolled. Tissue oxygenation (StO2%) measurements were performed at three different localizations of the gastric wall, prior and after the creation of the gastric pouch, and after the creation of the gastro-jejunostomy.

Results

Prior to the creation of the gastric pouch, the lowest StO2% levels were observed at the level of the distal esophagus with a median StO2% of 43 (IQR 40.8–49.5). After the creation of the gastric pouch and after the creation of the gastro-jejunostomy, the lowest StO2% levels were recorded at the level of the His angle with median values of 29% (IQR 20–38.5) and 34.5% (IQR 19–39), respectively. The highest mean StO2 reduction was recorded at the level of the His angle after the creation of the gastric pouch, and it was 18.3% (SD ± 18.1%, p < 0.001). A reduction of StO2% was recorded at all localizations after the formation of the gastro-jejunostomy compared to the beginning of the operation, but the mean differences of the StO2% levels were statistically significant only at the resection line of the pouch and at the His angle (p = 0.044 and p < 0.001, respectively).

Conclusion

Gastric pouch demonstrates reduction of StO2% during LRYGB. VLS is a useful technique to assess microperfusion patterns of the stomach during LRYGB.

Graphical abstract

     

Development of an auxotrophic oral live Shigella flexneri vaccine

An oral live attenuated Shigella flexneri vaccine candidate strain was constructed by making it auxotrophic and dependent on aromatic metabolites not available in mammalian tissues. An aroD gene of Escherichia coli K12 strain NK 5131, inactivated by insertion in it of the Tn 10 transposon, was transduced using phage P1 into a virulent S. flexneri serotype Y strain (Sfl 1) isolated from a patient with bacillary dysentery. One of the transductant strains Sfl 114 was found to invade HeLa cells in vitro, to cause plaque formation in HeLa monolayers (i.e. maintain intracellular multiplication in vitro), but to be unable to cause keratoconjunctivitis in guinea-pig eyes. When the strain was fed to Macacca fascicularis monkeys it was well tolerated, excreted for 1-4 days, and found to elicit a local intestinal sIgA and serum IgA, IgM and IgG responses. Monkeys challenged with 100 ID50 dose (1 X 10(11) bacteria) of the virulent parent Sfl 1 strain were completely protected from development of diarrhoea. Coloscopy of the monkeys and the sampling of intestinal biopsies showed that the vaccine protected against the surface epithelial erosions and ulcerations seen in unimmunized monkeys. Killing of invading virulent shigellae apparently took place intracellularly in the mucosa suggesting that cellular immune mechanisms played a role in the elicited host defence. The constructed S. flexneri Sfl 114 strain has the properties of a promising shigella vaccine and will next be the subject of studies with human volunteers.     

Effects of low and high dose oral contraceptives on blood coagulation and thrombogenesis induced by vascular subendothelium exposed to flowing human blood.

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Cysticercosis of the brain. The value of computed tomography

Incidence and radiologic findings of neurocysticercosis were investigated in a series of 23,800 consecutive head examinations using computed tomography (CT). The condition was diagnosed in 168 cases (0.7%). The parenchymatous form was the most common presentation (96.3%), while the meningeal form corresponded to only 11.9 per cent of cases. These two forms coexisted in some cases. These findings reversed the knowledge on the condition based on conventional radiography. The different CT appearances in the brain are described and a new radiologic protocol for the CT evaluation of the condition is advocated, which includes a follow-up after a trial cure with Praziquantel in the presence of cysts not associated with suggestive brain calcifications. CT was more sensitive than conventional radiography in the differentiation between dead and living larvae, thus having an impact on the therapeutic management of the patients.     

Quantitative and comparative study of haematoporphyrin-derived photosensitizers on a murine tumour model

Eight commercially available HPD-photosensitizers intended for photodynamic therapy were tested in a murine tumour model with regard to their therapeutic efficacy. The regrowth delay of the fibrosarcoma SSK-2 on the mouse C3H, Neuherberg-line, was determined 3, 24, 48 and 72 h after injection of the drugs (dose: 9 mg kg^–1 body weight). The corresponding pharmacodynamics, as measured by regrowth delay, were approximated by an exponential function and the characterizing coefficients derived. These coefficients served to quantify the photodynamic properties of the drugs.The pharmacodynamics of five substances were compared with those obtained fluorometrically. The latter showed shorter decay constants than the therapy-correlated substances which indicates different metabolic behaviour of the therapeutic and diagnostically useful fluorescent components of haematoporphyrin-derived photosensitizers.     

Assessment of the potential in vivo genotoxicity of fluoranthene

Fluoranthene is a ubiquitous environmental pollutant. Althoughfluoranthene is mutagenic in bacterial and mammalian in vitrocell systems following metabolic activation by rat liver fraction,information on in vivo mutagenicity is lacking and studies ontumour initiating activity in mice are equivocal. In the presentstudy, the potential genetic hazard to man was assessed usingthe mouse bone marrow micronucleus and rat liver unscheduledDNA synthesis test systems. Fluoranthene did not show any evidenceof genotoxicity in either of the in vivo assays following acuteoral administration at levels of up to 2000 mg/kg b.w. ¹To whom correspondence should be addressed     

Antibody response and protection against challenge in mice vaccinated intraperitoneally with a live aroA O4-O9 hybrid Salmonella dublin strain.

An auxotrophic Salmonella dublin (O9,12) strain, SL5631, with a deletion affecting gene aroA, was made into a partial diploid expressing the rfb (O-antigen-repeat-unit-specifying) gene cluster of Salmonella typhimurium (O4,12). By use of O4- and O9-specific antisera in indirect immunofluorescence assays, the resulting hybrid SL7103 was shown to express both the O4- and O9-antigen epitopes in the same bacterium. Qualitative and quantitative sugar analyses by gas-liquid chromatography on peralditol acetates of phenol-water-extracted lipopolysaccharides showed that the S. dublin and S. typhimurium repeating units (estimated on the basis of their tyvelose and abequose contents, respectively) were present in approximately equimolar amounts. The SL7103 hybrid auxotroph was avirulent when given intraperitoneally to NMRI mice in a dose of 10(8) CFU and elicited a protective immunity against intraperitoneal challenge with either virulent S. dublin (50% lethal dose of ca. 1.5 x 10(4) CFU versus < 1 x 10(1) CFU in nonimmunized mice) or virulent S. typhimurium (50% lethal dose of ca. 1 x 10(5) versus < 1 x 10(1) CFU in nonimmunized mice). Compared with the protection elicited in homologous systems (S. dublin SL5631 against S. dublin and S. typhimurium SL1479 against S. typhimurium), the protective efficacy of the hybrid was reduced approximately 70-fold against S. dublin challenge and 100-fold against S. typhimurium challenge. Vaccination with S. typhimurium SL1479 conferred no protection against S. dublin challenge, and vaccination with S. dublin SL5631 conferred no protection against S. typhimurium challenge. The protection elicited by the hybrid strain SL7103 is supposed to be mainly a consequence of serum antibodies directed against the immunodominant O4 and O9 epitopes.