Association of intraluminal thrombus in abdominal aortic aneurysm with local hypoxia and wall weakening

PURPOSE

Our previous computer models suggested that intraluminal thrombus (ILT) within an abdominal aortic aneurysm (AAA) attenuates oxygen diffusion to the AAA wall, possibly causing localized hypoxia and contributing to wall weakening. The purpose of this work was to investigate this possibility.

METHODS

In one arm of this study, patients with AAA were placed in one of two groups: (1) those with an ILT of 4-mm or greater thickness on the anterior surface or (2) those with little (< 4 mm) or no ILT at this site. During surgical resection but before aortic cross-clamping, a needle-type polarographic partial pressure of oxygen (PO2) electrode was inserted into the wall of the exposed AAA, and the PO2 was measured. The probe was advanced, and measurements were made midway through the thrombus and in the lumen. Mural and mid-ILT PO2 measurements were normalized by the intraluminal PO2 measurement to account for patient variability. In the second arm of this study, two AAA wall specimens were obtained from two different sites of the same aneurysm at the time of surgical resection: group I specimens had thick adherent ILT, and group II specimens had thinner or no adherent ILT. Nonaneurysmal tissue was also obtained from the infrarenal aorta of organ donors. Specimens were subjected to histologic, immunohistochemical, and tensile strength analyses to provide data on degree of inflammation (% area inflammatory cells), neovascularization (number of capillaries per high-power field), and tensile strength (peak attainable load). Additional specimens were subjected to Western blotting and immunohistochemistry for qualitative evaluation of expression of the cellular hypoxia marker oxygen-regulated protein.

RESULTS

The PO2 measured within the AAA wall in group I (n = 4) and group II (n = 7) patients was 18% +/- 9% luminal value versus 60% +/- 6% (mean +/- SEM; P <.01). The normalized PO2 within the ILT of group I patients was 39% +/- 10% (P =.08 with respect to the group I wall value). Group I tissue specimens showed greater inflammation (P <.05) compared with both group II specimens and nonaneurysmal tissue: 2.9% +/- 0.6% area (n = 7) versus 1.7% +/- 0.3% area (n = 7) versus 0.2% +/- 0.1% area (n = 3), respectively. We found similar differences for neovascularization (number of vessels/high-power field), but only group I versus control was significantly different (P <.05): 16.9 +/- 1.6 (n = 7) vs 13.0 +/- 2.3 (n = 7) vs 8.7 +/- 2.0 (n = 3), respectively. Both Western blotting and immunohistochemistry results suggest that oxygen-regulated protein is more abundantly expressed in group I versus group II specimens. Tensile strength of group I specimens was significantly less (P <.05) than that for group II specimens: 138 +/- 19 N/cm2 (n = 7) versus 216 +/- 34 N/cm2 (n = 7), respectively.

CONCLUSION

Our results suggest that localized hypoxia occurs in regions of thicker ILT in AAA. This may lead to increased, localized mural neovascularization and inflammation, as well as regional wall weakening. We conclude that ILT may play an important role in the pathology and natural history of AAA.

AppppA, heat-shock stress, and cell oxidation

Salmonella typhimurium LT2 induces a set of heat-shock proteins analogous to those found previously in Escherichia coli. These are virtually the only proteins synthesized after a temperature shift from 28 degrees C to 50 degrees C. Using a two-dimensional thin-layer chromatographic system developed to resolve adenylylated nucleotides, we have found that S. typhimurium and E. coli accumulate P1,P4-diadenosine-5'-tetraphosphate (AppppA), P1-(adenosine-5')-P3-(guanosine-3'-diphosphate-5')-triphosphate (ApppGpp), P1-(adenosine-5')-P4-(guanosine-5')-tetraphosphate (AppppG), P1-(adenosine-5')-P3-(guanosine-5')-triphosphate (ApppG), and P1,P3-diadenosine-5'-triphosphate (ApppA) after heat shock. These same adenylylated nucleotides accumulate after exposure to ethanol, an agent also known to induce the heat-shock response in a variety of cells. AppppA, ApppGpp, AppppG, ApppG, and ApppA were previously shown to accumulate under conditions of oxidation stress. We proposed that these adenylylated nucleotides may be alarmones--i.e., regulatory molecules, alerting cells to the onset of oxidation stress. The finding that these dinucleotides accumulate in response to heat shock suggests that oxidation and heat shock have a common physiological effect on cells. We hypothesize that these dinucleotides signal the onset of these stresses and trigger the "heat-shock response."

AppppA and related adenylylated nucleotides are synthesized as a consequence of oxidation stress

AppppA , ApppGpp , AppppG , ApppG , and ApppA rapidly accumulate to high levels in Salmonella typhimurium following exposure to a variety of oxidizing agents, but not to a variety of other stresses. Among the agents inducing these adenylylated nucleotides are 1-chloro-2,4-dinitrobenzene, diamide, hydrogen peroxide, t-butyl hydroperoxide, N-ethyl maleimide, iodoacetamide, cadmium chloride, and a variety of quinones. Some of these oxidizing agents cause preferential synthesis of specific adenylylated nucleotides, e.g., N-ethyl maleimide induces ApppA and menadione induces ApppGpp . Our data, as well as other evidence in the literature, strongly suggest that oxidation stress is coupled to adenylylated nucleotide synthesis by aminoacyl-tRNA synthetases. Although adenylylated nucleotides are made by tRNA synthetases in vitro, their synthesis in vivo is not a simple consequence of inhibition of synthetase activity. Compounds that inhibit normal charging by aminoacyl-tRNA synthetases do not result in the synthesis of adenylylated nucleotides, nor do mutations in tRNA synthetase structural genes or tRNA structural, modifying, or processing genes. We propose that the family of adenylylated nucleotides are alarmones signaling the onset of oxidation stress, and that particular ones may be alarmones for specific oxidative stresses, e.g., ApppGpp for oxidative damage to amino acid biosynthesis.

Isolation and characterization of a new succinic acid-producing bacterium, Mannheimia succiniciproducensMBEL55E, from bovine rumen

A novel succinic acid-producing bacterium was isolated from bovine rumen. The bacterium is a non-motile, non-spore-forming, mesophilic and capnophilic gram-negative rod or coccobacillus. Phylogenetic analysis based on the 16S rRNA sequence and physiological analysis indicated that the strain belongs to the recently reclassified genus Mannheimia as a novel species, and has been named Mannheimia succiniciproducens MBEL55E. Under 100% CO(2) conditions, it grows well in the pH range of 6.0-7.5 and produces succinic acid, acetic acid and formic acid at a constant ratio of 2:1:1. When M. succiniciproducensMBEL55E was cultured anaerobically in medium containing 20 g l(-1) glucose as carbon source, 13.5 g l(-1) of succinic acid was produced.

Capuchin stone tool use in Caatinga dry forest

Wild capuchin monkeys inhabiting dry forest were found to customarily use tools as part of their extractive foraging techniques. Tools consisted of twigs and sticks, often modified, which were used to probe for insects and, most frequently, of stones of a variety of sizes and shapes used for cracking and digging. The use of tools for digging has been thought to be restricted to humans. These monkeys, living in a harsh dry habitat, survive food limitation and foraging time constraints through their extensive tool use.

Metabolic engineering towards biotechnological production of carotenoids in microorganisms

Carotenoids are important natural pigments produced by many microorganisms and plants. Traditionally, carotenoids have been used in the feed, food and nutraceutical industries. The recent discoveries of health-related beneficial properties attributed to carotenoids have spurred great interest in the production of structurally diverse carotenoids for pharmaceutical applications. The availability of a considerable number of microbial and plant carotenoid genes that can be functionally expressed in heterologous hosts has opened ways for the production of diverse carotenoid compounds in heterologous systems. In this review, we will describe the recent progress made in metabolic engineering of non-carotenogenic microorganisms for improved carotenoid productivity. In addition, we will discuss the application of combinatorial and evolutionary strategies to carotenoid pathway engineering to broaden the diversity of carotenoid structures synthesized in recombinant hosts.

Sero-clearance of hepatitis B surface antigen in chronic carriers does not necessarily imply a good prognosis

The incidence of delayed hepatitis B surface antigen (HBsAg) clearance in the natural history of chronic hepatitis B virus (HBV)-infected patients was low. Previous studies regarding the prognosis in such patients were controversial. Among 1,355 chronic carriers from 1985 to 1997, spontaneous HBsAg clearance was observed in 55 patients. During a mean follow-up period of 23 months, 18 (32.7%; all were male subjects) developed serious complications, including 11 with hepatocellular carcinoma (HCC) (9 of them underwent surgical resection), 6 with cirrhosis, and 1 with subfulminant liver failure. The overall cumulative probability of complications was 29.8% at 4 years, and it was higher in males (P = .044) and patients aged 45 years or more (P = .006); the latter carried an 8.6-fold increased risk (95% CI: 1.2-64.6; P = .037) of adverse events. Histories of acute or chronic infection by hepatitis A virus, C virus (HCV), or D virus (HDV) were present in 42% of patients. Patients seropositive for antibodies against HCV (anti-HCV) or HDV (anti-HDV) had higher alanine transaminase (ALT) levels (>40 U/L; P = .008) after sero-clearance. HBV DNA was detectable in 31% of 51 subjects, in 20% of 20 with antibodies against HBsAg, in 40% of 20 with anti-HCV or anti-HDV, and also in an HCC patient's serum and tumor. Staining of liver HBsAg was positive in 30% of 10 HCC patients. In conclusion, our results demonstrated that hepatitis B viremia may persist, and adverse complications were not rare in HBsAg-clearance patients. All such patients should be closely monitored, which may allow for earlier detection of HCC.

Variations in frequencies of drug resistance in Plasmodium falciparum

Continual exposure of malarial parasite populations to different drugs may have selected not only for resistance to individual drugs but also for genetic traits that favor initiation of resistance to novel unrelated antimalarials. To test this hypothesis, different Plasmodium falciparum clones having varying numbers of preexisting resistance mechanisms were treated with two new antimalarial agents: 5-fluoroorotate and atovaquone. All parasite populations were equally susceptible in small numbers. However, when large populations of these clones were challenged with either of the two compounds, significant variations in frequencies of resistance became apparent. On one extreme, clone D6 from West Africa, which was sensitive to all traditional antimalarial agents, failed to develop resistance under simple nonmutagenic conditions in vitro. In sharp contrast, the Indochina clone W2, which was known to be resistant to all traditional antimalarial drugs, independently acquired resistance to both new compounds as much as a 1,000 times more frequently than D6. Additional clones that were resistant to some (but not all) traditional antimalarial agents acquired resistance to atovaquone at high frequency, but not to 5-fluoroorotate. These findings were unexpected and surprising based on current views of the evolution of drug resistance in P. falciparum populations. Such new phenotypes, named accelerated resistance to multiple drugs (ARMD), raise important questions about the genetic and biochemical mechanisms related to the initiation of drug resistance in malarial parasites. Some potential mechanisms underlying ARMD phenotypes have public health implications that are ominous.

Impaired wound healing and angiogenesis in eNOS-deficient mice

A role for nitric oxide (NO) in wound healing has been proposed; however, the absolute requirement of NO for wound healing in vivo and the contribution of endothelial NO synthase (eNOS) have not been determined. Experiments were carried out using eNOS gene knockout (KO) mice to determine the requirement for eNOS on wound closure and wound strength. Excisional wound closure was significantly delayed in the eNOS KO mice (29.4 +/- 2.2 days) compared with wild-type (WT) controls (20.2 +/- 0.4 days). At 10 days, incisional wound tensile strength demonstrated a 38% reduction in the eNOS KO mice. Because effective wound repair requires growth factor-stimulated angiogenesis, in vitro and in vivo angiogenesis assays were performed in the mice to assess the effects of eNOS deficiency on angiogenesis. Endothelial cell sprouting assays confirmed in vitro that eNOS is required for proper endothelial cell migration, proliferation, and differentiation. Aortic segments harvested from eNOS KO mice cultured with Matrigel demonstrated a significant reduction in endothelial cell sprouting and [(3)H]thymidine incorporation compared with WT mice at 5 days. Capillary ingrowth into subcutaneously implanted Matrigel plugs was significantly reduced in eNOS KO mice (2.67 +/- 0.33 vessels/plug) compared with WT mice (10.17 +/- 0.79 vessels/plug). These results clearly show that eNOS plays a significant role in facilitating wound repair and growth factor-stimulated angiogenesis.

Ecology and energetics of encephalization in hominid evolution

Hominid evolution is marked by very significant increase in relative brain size. Because relative brain size has been linked to energetic requirements it is possible to look at the pattern of encephalization as a factor in the evolution of human foraging and dietary strategies. Major expansion of the brain is associated with Homo rather than the Hominidae as a whole, and the energetic costs are likely to have forced a prolongation of growth rates and secondary altriciality. It is calculated here that modern human infants have energetic requirements approximately 9% greater than similar size apes due to their large brains. Consideration of energetic costs of brain allow the prediction of growth rates in hominid taxa and an examination of the implications for life-history strategy and foraging behaviour.

Weight loss associated with sodium-glucose cotransporter-2 inhibition: a review of evidence and underlying mechanisms

With their novel, insulin-independent mechanism, sodium-glucose cotransporter-2 (SGLT2) inhibitors are a major turning point in the management of type 2 diabetes mellitus. At present, there are several SGLT2 inhibitors available or in development, and these oral anti-hyperglycaemic agents lower plasma glucose through the inhibition of SGLT2-mediated reuptake of filtered glucose in the kidney. This unique mechanism of action is also expected to result in other beneficial effects, such as weight loss and blood pressure reduction. In various studies, including randomized controlled trials and real-world studies, patients treated with SGLT2 inhibitors have reported weight loss of around 1 to 3 kg. This review describes the characteristics of weight loss associated with SGLT2 inhibitor therapy, the clinical factors affecting SGLT2 inhibitor-associated weight loss and the possible underlying mechanisms of SGLT2 inhibitor-associated weight loss, including changes in metabolism and body composition, and the role of a reduction in insulin dose and compensatory hyperphagia. Understanding the weight loss effect of SGLT2 inhibitors, its related factors and underlying mechanisms can aid clinicians in optimal treatment decision-making, provide valuable insight on both obesity and diabetes management and reveal areas of future research and new therapeutic options.

Attenuation of myocardial ischemia/reperfusion injury by superinduction of inducible nitric oxide synthase

BACKGROUND

Nitric oxide (NO) has been implicated as a mediator in myocardial ischemia/reperfusion (I/R) injury, but its functional properties have been conflicting. We investigated whether NO has a protective role against I/R injury.

METHODS AND RESULTS

Using endothelial NO synthase knockout (eNOS KO) mice, inducible NOS KO mice, the NO donor S-nitroso-N-acetylpenicillamine (SNAP), and the NOS inhibitor N-iminoethyl-L-ornithine (L-NIO), we performed studies of isolated perfused hearts subjected to 30 minutes of global ischemia followed by reperfusion. After 60 minutes of reperfusion, nitrite levels in the coronary effluent in the SNAP and eNOS KO groups were significantly elevated compared with other groups. Immunoblot and immunohistochemistry showed that iNOS was markedly induced in the eNOS KO hearts. Under spontaneous beating conditions during reperfusion, increased NO activity was correlated with a prevention of the hyperdynamic contractile response and enhanced myocardial protection, as evidenced by a reduction in myocardial injury and infarct size. During prolonged reperfusion, SNAP-treated hearts were able to preserve contractile functions for 180 minutes, whereas L-NIO-treated hearts showed a sustained deterioration in contractility.

CONCLUSIONS

NO protects against I/R injury by preventing the hyperdynamic response of isolated perfused hearts during early reperfusion. In the eNOS KO hearts, a paradoxical increase in NO production was seen, accompanied by a superinduction of iNOS, possibly due to an adaptive mechanism.

The efficacy of an oscillating bed in the prevention of lower respiratory tract infection in critically ill victims of blunt trauma. A prospective study

We tested the hypothesis that the incidence of LRTI in critically ill blunt trauma victims can be reduced by employing continuous postural oscillation. Within 24 h of admission to the SICU, 106 patients were prospectively randomized to either a conventional bed or a RRKTT. Seven patients who were discharged from the SICU in less than 24 h were excluded from the data analyses. Until discharge from the SICU, patients were monitored daily for development of LRTI or pneumonia. Among 48 patients in the control group, 28 met criteria for LRTI and 19 met criteria for pneumonia. Among 51 patients in the RRKTT group, 13 developed LRTI and 7 developed pneumonia. The differences between groups for all LRTI and pneumonia were both significant. We conclude that continuous postural oscillation decreases the risk of pulmonary sepsis in victims of major blunt trauma.

Growth and ontogeny of sexual size dimorphism in the mandrill (Mandrillus sphinx)

We present body mass (N = 419) and crown-rump length (CRL, N = 210) measurements from 38 male and 49 female mandrills born into a semifree-ranging colony in order to describe growth from birth to adulthood, and to investigate maternal influences upon growth. Adult male mandrills are 3.4 times the body mass, and 1.3 times the CRL, of adult females. Body mass dimorphism arises from a combination of sex differences in length of the growth period (females attain adult body mass at 7 years, males at 10 years) and growth rate. Both sexes undergo a subadult growth spurt in body mass, and this is much more dramatic in males (peak velocity 551 g/months +/- 89 SEM at 84-96 months). CRL dimorphism arises from bimaturism (females attain adult CRL at 6 years, males after 10 years), and neither sex shows a particular subadult growth spurt in CRL. Sexual size dimorphism thus represents important time and metabolic costs to males, who mature physically approximately 3-4 years after females. Considerable interindividual variation occurs in the size-for-age of both sexes, which is related to maternal variables. Older mothers have heavier offspring than do younger mothers, and higher-ranking mothers have heavier offspring than do lower ranking mothers. Mass advantages conferred upon offspring during lactation by older and higher-ranking mothers tend to persist postweaning in both sexes. Thus maternal factors affect reproductive success in both sexes, influencing the age at which offspring mature and begin their reproductive career.

Effect of lipopolysaccharide on intestinal intramucosal hydrogen ion concentration in pigs: evidence of gut ischemia in a normodynamic model of septic shock

We tested the hypothesis that lipopolysaccharide (LPS) leads to an imbalance between mesenteric oxygen delivery (DO2) and gut metabolic demand for oxygen, even when cardiac index (CI) is within the normal range. Two groups of pentobarbital-anesthetized pigs (13 to 17 kg) were studied. The first group (LPS; n = 9) was infused over 20 min with Escherichia coli LPS (100 micrograms/kg) and resuscitated with normal saline (1.2 ml/kg.min). The second group (NS; n = 5) was not infused with LPS, but was resuscitated in the same way as the LPS group. Superior mesenteric arterial (SMA) blood flow and ileal intramucosal hydrogen ion concentration, [H+], were determined using a Doppler-shift probe and a tonometric catheter, respectively. Infusing LPS did not affect CI, although mean arterial pressure and systemic vascular resistance were significantly reduced. SMA flow and mesenteric DO2 decreased significantly in the LPS group. Although mesenteric oxygen utilization was well preserved in both groups, ileal intramucosal [H+] was significantly higher in endotoxic animals. These data support the idea that mesenteric oxygen consumption is flow-limited in this clinically relevant porcine model of septic shock.

Finite social space, evolutionary pathways, and reconstructing hominid behavior

Changes in social behavior were a key aspect of human evolution, and yet it is notoriously difficult for paleobiologists to determine patterns of social evolution. By defining the limited number of distributional strategies available to members of each sex of any species and investigating the conditions under which they may occur and change, the social behavior of different hominid taxa may be reconstructed.

Management of splenic artery aneurysms: the significance of portal and essential hypertension

BACKGROUND

Splenic artery aneurysm(s) (SAA) are rare. But the incidence and significance of SAA among patients with portal hypertension (PHTN), especially among those who undergo orthotopic liver transplantation (OLT), have not been clearly delineated.

STUDY DESIGN

An 11-year (February 1987 to June 1998) retrospective review of our experience with treated SAA was performed. Patient characteristics, risk factors, clinical presentation, surgical management, aneurysm characteristics, and patient outcomes were assessed. Patients were separated according to a history of PHTN for analysis. Patients were also subdivided into ruptured versus elective presentations.

RESULTS

Thirty-four patients (22 in the PHTN group) were treated for SAA during the study period. Sixty-two percent (21 of 34) were women; the average age was 50.6 years. In patients without a history of PHTN (n = 12), essential hypertension was a significant risk factor (p < 0.001) for development of SAA. All patients underwent surgical treatment for SAA: resection with splenectomy (n = 23), ligation with splenectomy (n = 5), ligation of SAA only (n = 4), and vascular reconstruction (n = 2). The average size of all treated SAA was 4.8 +/- 2.6 cm, ranging from 1.5 to 12cm. Operative mortality after SAA rupture (n = 15) was 40%, compared with zero mortality for elective SAA repair (n = 19, p < 0.005). Rupture of SAA was associated with a higher mortality in patients with PHTN compared with patients without such history (56% versus 17%, respectively). After a mean followup period of 46 months, survival after rupture was 60% in contrast to 84% after elective repair. The majority of our patients with a history of PHTN (20 of 22) has undergone OLT, representing 0.46% of all OLT recipients (n = 4,374) during the study period. In four patients, SAA were repaired concurrently during transplantation. Of the 7 patients presented with rupture of SAA after OLT, 6 patients presented within 3 to 16 days postoperatively, with a median of 6 days and an overall mortality of 57%.

CONCLUSIONS

Essential hypertension and PHTN appear to be significant risk factors for development of SAA. Rupture of SAA is associated with a significant mortality, highest among patients with PHTN. Elective repair remains a safe and effective method of treatment. The significance of SAA is recognized among patients undergoing liver transplantation. A decision should be made to screen and electively treat SAA found in liver transplant patients, especially if the aneurysm is larger than 1.5 cm. Awareness of the increased rupture risk is crucial in management during the immediate posttransplant period.

Macrophage accumulation associated with rat cardiac allograft rejection detected by magnetic resonance imaging with ultrasmall superparamagnetic iron oxide particles

BACKGROUND

Acute cardiac allograft rejection continues to be the cause of graft loss and contributes to the morbidity and mortality after cardiac transplantation. In this study, we report a new method for detecting organ rejection in transplantation with an MR-based technique using dextran-coated ultrasmall superparamagnetic iron oxide (USPIO) particles. These particles ( approximately 27 nm in diameter) are known to shorten relaxation times in MRI experiments.

METHODS AND RESULTS

A new rat model of heterotopic heart and lung transplantation has been developed for MRI experiments. Allotransplantations (DA-->BN) were performed (n=8), with syngeneic transplantations (BN-->BN) serving as controls (n=8). MR images were obtained with a gradient echo method. At postoperative day 7, allotransplants developed moderate rejection as determined histopathologically. A significant reduction in MR signal intensity was observed after USPIO injection into rats with allotransplanted hearts. Syngeneic transplants showed no differences in MR signal intensity before and after USPIO injections. After injection of USPIO particles at postoperative day 6, a group of allotransplanted rats was treated with cyclosporin A (3 mg/kg). Animals treated with cyclosporin A for 7 days showed no reduction in MR signal intensity after USPIO reinjection at day 14, whereas animals treated for 4 days showed a significant decrease in MR signal intensity in the transplanted hearts indicative of acute graft rejection. Pathological analysis of these animals revealed that dextran-coated USPIO particles were taken up by the infiltrating macrophages that accumulated within the rejecting cardiac graft.

CONCLUSIONS

This MRI method offers promise as a noninvasive method for detecting transplant allograft rejection.

Gut microbiota and metabolites associate with outcomes of immune checkpoint inhibitor-treated unresectable hepatocellular carcinoma

Background

Immune checkpoint inhibitors (ICIs) are promising agents for unresectable hepatocellular carcinoma (uHCC), but lack effective biomarker to predict outcomes. The gut microbiome can modulate tumor response to immunotherapy, but its effect on HCC remains unclear.

Methods

From May 2018 to February 2020, patients receiving ICI treatment for uHCC were prospectively enrolled; their fecal samples were collected before treatment. The fecal microbiota and metabolites were analyzed from 20 patients with radiology-proven objective responses (OR) and 21 randomly selected patients with progressive disease (PD). After March 2020, 33 consecutive Child-Pugh-A patients were recruited as a validation cohort. Additionally, feces from 17 healthy volunteers were collected for comparison of background microbes.

Results

A significant dissimilarity was observed in fecal bacteria between patients with OR and patients with PD before immunotherapy. Prevotella 9 was enriched in patients with PD, whereas Lachnoclostridium, Lachnospiraceae, and Veillonella were predominant in patients with OR. Ursodeoxycholic acid and ursocholic acid were significantly enriched in the feces of patients with OR and strongly correlated with the abundance of Lachnoclostridium. The coexistence of Lachnoclostridium enrichment and Prevotella 9 depletion significantly predicted better overall survival (OS). In the validation cohort, better progression-free survival (PFS) and OS were noted in patients who had a preferable microbial signature in comparison with counter-group (PFS: 8.8 months vs 1.8 months; OS: not reached vs 6.5 months, both p<0.001).

Conclusions

Fecal microbiota and bile acids were associated with outcomes of immunotherapy for uHCC. These findings highlight the potential role of gut microbiota and metabolites as biomarkers to predict outcomes of ICI-treated HCC.

Are low tidal volumes safe?

High airway pressure may be injurious to lung parenchyma, but lowering airway pressure using conventional mechanical ventilation necessitates lowering tidal volume (VT). Intubated patients in the surgical intensive care unit (SICU) were randomly assigned to group 1 (VT = 12 ml/kg, n = 56) or group 2 (VT = 6 ml/kg, n = 47). Variables recorded included acute physiology and chronic health evaluation (APACHE II) score, mean peak airway pressure (MPAP), mean PaO2/FIO2, incidence of pulmonary infectious complications (PIC), duration of intubation (DOI), and duration of SICU stay (DOS). Results in the table are means +/- SE. (table; see text) The incidence of pulmonary infection tended to be lower and DOI and DOS tended to be shorter for nonneurosurgical and noncardiac surgical patients randomized to low VT, suggesting that morbidity may be decreased. The use of low VT was associated with a statistically significant but clinically irrelevant decrease in oxygenation. The routine use of low VT appeared to be safe in a selected population of patients in the SICU.

Predictors of Response and Survival in Immune Checkpoint Inhibitor-Treated Unresectable Hepatocellular Carcinoma

Immune checkpoint inhibitors (ICIs) with nivolumab and pembrolizumab are promising agents for advanced hepatocellular carcinoma (HCC) but lack of effective biomarkers. We aimed to investigate the potential predictors of response and factors associated with overall survival (OS) for ICI treatment in unresectable HCC patients. Ninety-five patients who received nivolumab or pembrolizumab for unresectable HCC were enrolled for analyses. Radiologic evaluation was based on RECIST v1.1. Factors associated with outcomes were analyzed. Of 90 patients with evaluable images, the objective response rate (ORR) was 24.4%. Patients at Child-Pugh A or received combination treatment had higher ORR. Early alpha-fetoprotein (AFP) >10% reduction (within 4 weeks) was the only independent predictor of best objective response (odds ratio: 7.259, p = 0.001). For patients with baseline AFP ≥10 ng/mL, significantly higher ORR (63.6% vs. 10.2%, p < 0.001) and disease control rate (81.8% vs. 14.3%, p < 0.001) were observed in those with early AFP reduction than those without. In addition, early AFP reduction and albumin-bilirubin (ALBI) grade or Child-Pugh class were independent factors associated with OS in different models. In conclusion, a 10-10 rule of early AFP response can predict objective response and survival to ICI treatment in unresectable HCC. ALBI grade and Child-Pugh class determines survival by ICI treatment.

The prevalence and clinical characteristics of celiac disease in juvenile diabetes in Wisconsin

BACKGROUND

The relationship between celiac disease and juvenile diabetes has long been known. Only a single study in the United States, from Buffalo, New York, has reported the prevalence of celiac disease in a pediatric diabetic population. This study was conducted to determine the prevalence and clinical presentation of celiac disease in children and adolescents with juvenile diabetes in Wisconsin, USA, using serum antiendomysial antibody as a screening test.

METHODS

Two hundred eighteen patients with diabetes (113 males; age range, 4-21 years) and 117 age-and gender-matched control participants were tested for immunoglobulin A endomysial antibody. Patients with positive results were offered a small bowel biopsy. A questionnaire regarding abdominal pain, diarrhea, and growth failure was completed by the parents.

RESULTS

Seventeen of 218 diabetic patients (7.7%) had positive endomysial antibody. All control participants had negative results for the endomysial antibody. Small bowel biopsy was performed in 14 patients. Ten patients had villous atrophy. In one patient without villous atrophy, a repeat biopsy 2 years later showed villous atrophy, and two patients had increased intraepithelial lymphocytes without villous atrophy. Seventy percent of the patients with celiac disease were asymptomatic. The reported symptoms were abdominal pain and diarrhea (n = 1) and growth failure (n = 2). Two patients with celiac disease had Down syndrome.

CONCLUSIONS

The prevalence of celiac disease in children with juvenile diabetes in Wisconsin is at least 4.6%, which is comparable with European and Canadian studies. Because patients without villous atrophy may have latent celiac disease, the prevalence may be even higher. All children with juvenile diabetes should be screened for celiac disease.

Biological conversion of wood hydrolysate to succinic acid by Anaerobiospirillum succiniciproducens

Anaerobiospirillum succiniciproducens grew on a minimal salts medium containing wood hydrolysate (equivalent to 27 g glucose l(-1)) and, when supplemented with 10 g corn steep liquor l(-1) as a complex nitrogen source, succinic acid at 24 g l(-1) was obtained (yield = 88% w/w glucose). This may therefore be an economical method to produce succinic acid.

Disruption of male reproductive tract development by administration of the xenoestrogen, nonylphenol, to male newborn rats

Nonylphenol (NP) treatment of neonatal male rat pups decreased the size of their testes, epididymis, seminal vesicle, and ventral prostate, and increased the frequency of cryptorchidism (60.7%, n = 56 vs 0% in vehicle-treated control, n = 58) when examined at 31 d of age. NP effects are dose-dependent. These effects were only seen when NP was given at > or =20.8 mg/kg daily for 15 d. There is a critical period of vulnerability to NP during male reproductive development in the neonatal stage. Changes were found when NPs were given to male pups before 13 d of age, but not when given at > or =13 d of age. NP acts on the male reproductive tissues through the estrogen receptor (ER), since concomitant treatment with ICI 182,780, a specific ER antagonist, blocked NP's effects on the testis and male accessory organs. NP-treated males in the neonatal period had greatly reduced their subsequent capacity to impregnate young fertile females. Our results suggest that exposure of neonatal male rats to NP is potentially deleterious to their reproductive development and affects their reproductive performance.