Alteration in faecal bile acids, gut microbial composition and diversity after laparoscopic sleeve gastrectomy.

BACKGROUND: Laparoscopic sleeve gastrectomy (LSG) is a well established treatment for severe obesity and type 2 diabetes. Although the gut microbiota is linked to the efficacy of LSG, the underlying mechanisms remain elusive. The effect of LSG for morbid obesity on the gut microbiota and bile acids was assessed here. METHODS: Severely obese subjects who were candidates for LSG were included and followed until 6 months after surgery. The composition and abundance of the microbiota and bile acids in faeces were assessed by 16S ribosomal RNA sequencing, quantitative PCR and liquid chromatography-mass spectrometry. RESULTS: In total, 28 patients with a mean(s.d.) BMI of 44·2(6·6) kg/m2 were enrolled. These patients had achieved excess weight loss of 53·2(19·0) per cent and showed improvement in metabolic diseases by 6 months after LSG, accompanied by an alteration in the faecal microbial community. The increase in α-diversity and abundance of specific taxa, such as Rikenellaceae and Christensenellaceae, was strongly associated with reduced faecal bile acid levels. These changes had a significant positive association with excess weight loss and metabolic alterations. However, the total number of faecal bacteria was lower in patients before (mean(s.d.) 10·26(0·36) log10 cells per g faeces) and after (10·39(0·29) log10 cells per g faeces) operation than in healthy subjects (10·83(0·27) log10 cells per g faeces). CONCLUSION: LSG is associated with a reduction in faecal bile acids and greater abundance of specific bacterial taxa and α-diversity that may contribute to the metabolic changes.

ANTECEDENTES: La gastrectomía vertical laparoscópica (laparoscopic sleeve gastrectomy, LSG) es un tratamiento bien establecido para la obesidad grave y la diabetes tipo 2. Aunque la microbiota intestinal se ha vinculado con la eficacia de LSG, los mecanismos subyacentes siguen siendo poco conocidos. En este estudio se evaluó el efecto de LSG en la obesidad mórbida sobre la microbiota del intestino y de los ácidos biliares (bile acids, BA). MÉTODOS: Tras la aprobación del Comité ético y la obtención del consentimiento informado, los sujetos con obesidad grave que eran candidatos para LSG fueron incluidos en el estudio y seguidos durante 6 meses después de la operación. Se evaluaron la composición y abundancia de la microbiota y BA en las heces mediante secuenciación del gen 16S rRNA, PCR cuantitativa y cromatografía líquida-espectrometría de masas. RESULTADOS: En total, 28 pacientes con una mediana (rango) del IMC de 43,9 kg/m2 (35,0-61,9) fueron reclutados y a los 6 meses tras una LSG, consiguieron una pérdida del exceso de peso de 47,3% (20,7-95,1) y mejoría de las enfermedades metabólicas acompañada de una alteración en la comunidad microbiana fecal. El aumento en la diversidad α y abundancia de especies taxonómicas específicas como Rikenellaceae y Christensenellaceae, se asociaba fuertemente con niveles fecales reducidos de BA. Estos cambios se asociaban de manera positiva y significativa con la pérdida del exceso de peso y las alteraciones metabólicas. Sin embargo, el número total de bacterias fecales en los pacientes fue inferior al de los sujetos sanos (10,84 log10 células/g heces (9,46-11,35)) antes de la operación (10,26 log10 células/g heces (9,44-10,91)) y después de la misma (10,42 log10 células/g heces (9,57-10,96)). CONCLUSIÓN: LSG se asoció con menos BA fecal y mayor abundancia de especies bacterianas específicas y diversidad α lo que puede contribuir a los cambios metabólicos.

Thymus histology and concomitant autoimmune diseases in Japanese patients with muscle-specific receptor tyrosine kinase-antibody-positive myasthenia gravis.

BACKGROUND AND PURPOSE: The differences in the characteristics of thymus histology, coexisting autoimmune diseases and related autoantibodies between anti-muscle-specific receptor tyrosine kinase (MuSK)-antibody (Ab)-positive myasthenia gravis (MG) patients, and anti-acetylcholine receptor (AChR)-Ab-positive MG patients are not clearly defined. METHODS: The types of thymus histology, coexisting autoimmune diseases and associated Abs in 83 MuSK-Ab-positive patients nationwide were investigated and were compared with those in AChR-Ab-positive patients followed at our institute (n = 83). As for the autoantibodies associated with thymoma, titin Abs were measured. RESULTS: Thymoma was not present in any of the MuSK-Ab-positive patients but presented in 21 patients (25.3%) amongst the AChR-Ab-positive patients. Titin Abs were absent in MuSK-Ab-positive patients but positive in 25 (30.1%) of the AChR-Ab-positive patients. Concomitant autoimmune diseases were present in eight MuSK-Ab-positive patients (9.6%) amongst whom Hashimoto's thyroiditis and rheumatoid arthritis predominated, whereas 22 AChR-Ab-positive patients (26.5%) had one or more concomitant autoimmune diseases of which Graves' disease predominated. CONCLUSIONS: Differences in frequency of thymoma and thymic hyperplasia, coexisting autoimmune diseases and autoantibody positivity between MuSK-Ab-positive and AChR-Ab-positive MG were indicated, suggesting that, in contrast with AChR-Ab-positive MG, thymus does not seem to be involved in the pathogenic mechanisms of MuSK-Ab-positive MG.

Different turnover rate of hepatitis C virus clearance by different treatment regimen using interferon-beta.

BACKGROUND/AIM: Since patients with high viral load and HCV subtype 1b are known to respond poorly to interferon (IFN) therapy, the viral dynamics of HCV RNA after initiation of interferon therapy were examined in the present study with respect to two different administration regimens, once vs. twice a day. METHODS: Twenty-two patients with chronic hepatitis C confirmed by liver biopsy and with >1 Meq/ml of HCV RNA and HCV subtype 1b were randomly assigned to two different IFN administration regimens (6 million units of IFN once a day or 3 million units of IFN twice a day), and the serum HCV RNA level was serially measured. RESULTS: Graphs of HCV RNA levels vs. treatment time showed an initial rapid fall, followed by a slower clearance phase. Fitting the data to a model for HCV decay proposed by Neumann et al. showed that the treatment efficacy was significantly higher with twice daily administration. Negativity for HCV RNA measured by Amplicor assay in the twice-a-day administration group was 18%, 73% and >89% at 1, 2 and 3 weeks, respectively, in contrast to 0%, 0%, and 18%, respectively, with once-a-day administration. However, a significant reduction of platelet count and albumin level, a marked increase in serum aspartate aminotransferase/alanine aminotransferase, and a high incidence of renal toxicity (proteinuria) were found in patients receiving IFN twice a day in comparison with those receiving it once a day. CONCLUSION: The twice-a-day administration of IFN accelerated the clearance of HCV RNA from serum, leading to a more efficient virological response for patients with chronic hepatitis C, but with a high rate of renal toxicity.

Effect of splenectomy on hepatic metastasis of colon carcinoma and natural killer activity in the liver.

We have previously demonstrated that administration of killed streptococcal preparation (OK432), a biological modifier, increased the number of asialo GM1-positive cells in the liver, enhanced NK activity of hepatic mononuclear cells, and reduced the number of hepatic metastases of colon 38 adenocarcinoma that were inoculated into the superior mesenteric vein of C57BL/6 strain mice. In the present study, to clarify the role of the spleen in immune surveillance of the liver, the effect of splenectomy on hepatic metastasis of colon carcinoma and on hepatic NK activity has been examined. The number of hepatic metastasis increased in the splenectomized mice, compared with that in sham-operated mice. Administration of OK432 increased the number of asialo GM1-positive cells in the liver and enhanced NK activity of hepatic mononuclear cells in both groups, but NK activity of hepatic mononuclear cells in the splenectomized mice was less than that of the sham-operated mice. An enhanced NK activity of these cells was abolished by treatment with anti-asialo-GM1 antibody plus complement in vitro. Interleukin-2 mRNA expression was increased in the spleen 2 hr after OK432 administration and persisted until 8 hr, but was scarcely noted in the liver. On the other hand, NK activity of hepatic mononuclear cells in the asialo GM1-positive cell-depleted (previous administration of antiserum against asialo GM1) mice was enhanced after OK432 administration in the sham operated and splenectomized mice, but an enhanced NK activity in these mice was only partially or not at all abolished by treatment with anti-asialo GM1 antibody plus complement in vitro, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Chemotactic factors released from hepatocytes exposed to acetaminophen.

To clarify the mechanism of neutrophil infiltration in the liver of acetaminophen-induced hepatic injury, chemotactic factor released from hepatocytes exposed to acetaminophen has been investigated. Hepatocytes exposed to acetaminophen release nondialyzable chemotactic factor, although acetaminophen in itself inhibits chemotaxis of neutrophils. Chemotactic activity of the nondialyzable chemotactic factor was reduced after treatment with heat (56 degrees C, 30 min) or trypsin. Chemotactic activity was demonstrated at the molecular weights of around 25 and 55 kDa. Chemotactic activity of the conditioned medium was not significantly reduced in the presence of antibody against rat KC/gro protein (interleukin-8-related cytokine in rodent). Chemotactic activity of a 25-kDa factor was reduced by the antibody against the antibody against KC/gro protein, but that of a 55-kDa factor was not reduced. Immunoblot analysis revealed that the peptide reacted with antibody against rat KC/gro protein was demonstrated at a molecular weight of around 20-25 kDa, but not around 55kDa, when the conditioned medium of acetaminophen-treated hepatocytes was electrophoresed. These results suggest that hepatocytes exposed to acetaminophen release two types of chemotactic factors for neutrophils and that a major part of the chemotactic factor could be different from a member of interleukin-8 family.

Growth regulation of rabbit gastric epithelial cells and protooncogene expression.

We recently developed a primary culture system for gastric epithelial cells from adult rabbits that allows the investigation of growth regulation at the cellular level. In this study, we demonstrated that epidermal growth factor (EGF), insulin, and dibutyryl adenosine 3',5'-cyclic monophosphate (dBcAMP) all stimulated cell proliferation. Insulin and dBcAMP potentiated the stimulation of cell proliferation by EGF, while transforming growth factor-beta 1 (TGF-beta 1) inhibited it. Expression of c-fos and c-myc was induced in response to the stimulation by these growth regulators, but the degree of expression did not necessarily correlate with the effects of these agents on cell proliferation. In conclusion, EGF, insulin, and dBcAMP were positive growth regulators, while TGF-beta 1 was a negative regulator in gastric epithelial cells. These growth modulators may exert their effects by distinct pathways from a standpoint of the expression of c-fos and c-myc.

Churg-Strauss syndrome (allergic granulomatous angiitis) with multiple perforating ulcers of the small intestine, multiple ulcers of the colon, and mononeuritis multiplex.

A case of Churg-Strauss syndrome with multiple perforations of the small intestine is described. A 31-year-old woman was admitted with a complaint of epigastric pain. She had a history of bronchial asthma. One week before admission, white blood cell count was 20,800/mm3 with 59% eosinophils. Neurological examination on admission disclosed mononeuritis multiplex with paresthesia in both the lower and upper extremities. At colonoscopy, there were scattered aphthous ulcers in the colon. Ophthalmological examination revealed allergic conjunctivitis. After admission, hypereosinophilia increased to as high as 36,000/mm3. Oral administration of prednisolone (60 mg/day) was begun. On the 3rd day of the treatment, the eosinophil count decreased dramatically, to 400/mm3, while severe abdominal pain developed. Since abdominal X-ray film revealed free air in the abdominal cavity, emergency laparotomy was performed and multiple intestinal ulcers with perforations were found. Partial ileectomy was performed. Pathological findings of the resected specimen were interpreted as a necrotizing angiitis with extravascular granuloma. Since the operation, the patient has been asymptomatic, except for neurological symptoms. Hypereosinophilia has decreased without treatment to counts averaging 270/mm3, within 3 months. On the basis of the clinical features and histopathological findings, a diagnosis of Churg-Strauss syndrome was established.

Inhibition of hepatic metastasis of colon carcinoma by asialo GM1--positive cells in the liver.

This study investigates the role of hepatic asialo GM1-positive cells in inhibiting hepatic metastasis of colon carcinoma (colon adenocarcinoma 38) in mice after administration of a biological response modifier, streptococcal derivative (OK432). Administration of OK432 increased the number of asialo GM1-positive cells in the liver, enhanced natural killer activity of hepatic mononuclear cells and reduced the number of hepatic metastases of colon carcinoma inoculated into the superior mesenteric vein. Administration of antiserum against asialo GM1 reduced the number of hepatic asialo GM1-positive cells, abolished natural killer activity of hepatic mononuclear cells and increased the number of hepatic metastases. In addition, administration of antiserum against asialo GM1 even after OK432 treatment also decreased the number of asialo GM1-positive cells, reduced natural killer activity of hepatic mononuclear cells and increased the number of hepatic metastases of colon carcinoma. However, administration of gadolinium chloride, which suppresses phagocytic function of Kupffer cells, did not influence the natural killer activity of hepatic mononuclear cells or the number of hepatic metastases. In vivo tumor-neutralization assay revealed that tumor growth was inhibited by the hepatic mononuclear asialo GM1-positive cells, but not by T lymphocytes or Kupffer cells after OK432 administration. These results suggest that an increased number of hepatic asialo GM1-positive cells after administration of OK432 plays an important role in protecting against metastasis of colon carcinoma in the liver.

The rat hepatocyte plasma membrane organic anion binding protein is immunologically related to the mitochondrial F1 adenosine triphosphatase beta-subunit.

A 55-kD organic anion binding protein (OABP) was identified previously in liver cell plasma membrane sinusoidal subfractions. Although this protein was localized to the surface of hepatocytes by immunofluorescence, immunoblot analysis revealed reactivity toward both plasma membrane and mitochondrial fractions. To clarify these findings, an immunoreactive clone from a rat liver cDNA expression library was isolated, the 1,500-base pair cDNA insert was sequenced, and the corresponding beta-galactosidase fusion protein was expressed and purified. The resulting sequence corresponded to that of the rat mitochondrial F1-adenosine triphosphatase (F1-ATPase) beta-subunit. This protein and OABP are of similar size and are mutually immunologically cross-reactive. That the antigen was present on the cell surface as well as in mitochondria was suggested from studies of immunoprecipitation after cell-surface iodination, and light- and electron-microscopic immunocytochemistry. Photoaffinity labeling of bovine F1-ATPase with high-specific-activity [35S]sulfobromophthalein revealed binding only to the beta-subunit. Hepatocyte uptake of bilirubin and sulfobromophthalein requires cellular ATP and mitochondria also transport these organic anions, which at high doses inhibit respiration. The presence of an organic anion binding site on the F1-ATPase beta-subunit suggests that it may play a role in these processes.

Influence of Cl- on organic anion transport in short-term cultured rat hepatocytes and isolated perfused rat liver.

Transport of 35S-labeled sulfobromophthalein [35S]BSP was studied in short-term cultured rat hepatocytes incubated in bovine serum albumin. At 37 degrees C, initial uptake of [35S]BSP was 5-10-fold that at 4 degrees C, linear for at least 15 min, saturable, inhibited by bilirubin, and reduced by greater than 70% after ATP depletion or isosmotic substitution of sucrose for NaCl in medium. Replacement of Na+ by K+ or Li+ did not alter uptake, whereas replacement of Cl- by HCO-3 or gluconate- reduced uptake by approximately 40%. Substitution of Cl- by the more permeant NO-3 enhanced initial BSP uptake by 30%. Efflux of [35S]BSP from cells to media was inhibited by 40% after ATP depletion or sucrose substitution. To confirm these results in a more physiologic system, transport of [3H]bilirubin was studied in isolated livers perfused with control medium or medium in which Cl- was replaced by gluconate-. Perfusion data analyzed by the model of Goresky, revealed 40-50% reductions in influx and efflux with gluconate- substitution. These results are consistent with existence of a Cl-/organic anion-exchange mechanism similar to that described by others in renal tubules.

External fixators for wrist fractures: a biomechanical and clinical study.

The rigidity of four external fixators for the wrist was determined by using the Instron universal testing instrument. Using the equivalent stiffness index, the small A.O. was 7.6, the mini Hoffman was 3.7, Roger Anderson was 3.5, and Ace Colles' was 4.3. Thus, the small A.O. was about twice as rigid overall as the other three external fixators. Twenty-two patients with unstable distal radius fractures were treated with the mini Hoffman external fixator over a 3-year period; and follow-up data were obtained. The average final angle of the distal radial articular surface on the anteroposterior x-ray film was 17.5 degrees. The final angle of the distal radial articular surface on the lateral x-ray film was 2 degrees dorsal. The final height of the distal radial styloid averaged 8 mm. The final range of motion of the wrist compared with the opposite normal hand was extension 77%, flexion 77%, ulnar deviation 82%, radial deviation 73%, pronation 84%, supination 78%, and grip strength 72%. Complications included three cases of broken pins, one of a pin loosening with migration, one case of tendon rupture, and one of intrinsic contracture. From our experience, the Hoffman external fixator gave adequate clinical and functional results and can be used safely in the small to average size patient. A more rigid external fixator should be used for larger and more active patients. External fixation is an excellent way to treat unstable distal radial fractures.