Serum vascular endothelial growth factor affects tissue fluid accumulation and is associated with deteriorating tissue perfusion and oxygenation in severe sepsis: a prospective observational study

BACKGROUND

Positive fluid balance and tissue fluid accumulation are associated with adverse outcomes in sepsis. Vascular endothelial growth factor (VEGF) increases in sepsis, promotes vascular permeability, and may affect tissue fluid accumulation and oxygenation. We used near-infrared spectroscopy (NIRS) to estimate tissue hemoglobin (Hb) oxygenation and water (H₂O) levels to investigate their relationship with serum VEGF levels.

MATERIAL AND METHODS

New-onset severe sepsis patients admitted to the intensive care unit were enrolled. Relative tissue concentrations of oxy-Hb ([HbO₂]), deoxy-Hb ([HbR]), total Hb ([HbT]), and H₂O ([H₂O]) were estimated by near-infrared spectroscopy (NIRS) for three consecutive days and serum VEGF levels were measured. Comparisons between oliguric and non-oliguric patients were conducted and the correlations between variables were analyzed.

RESULTS

Among 75 eligible patients, compared with non-oliguric patients, oliguric patients were administrated more intravascular fluids (median [IQR], 1926.00 [1348.50-3092.00] mL/day vs. 1069.00 [722.00-1486.75] mL/day, p < 0.001) and had more positive daily net intake and output (mean [SD], 1,235.06 [1303.14] mL/day vs. 313.17 [744.75] mL/day, p = 0.012), lower [HbO₂] and [HbT] over the three-day measurement (analyzed by GEE p = 0.01 and 0.043, respectively) and significantly higher [H₂O] on the third day than on the first two days (analyzed by GEE p = 0.034 and 0.018, respectively). Overall, serum VEGF levels were significantly negatively correlated with [HbO₂] and [HbT] (rho = - 0.246 and - 0.266, p = 0.042 and 0.027, respectively) but positively correlated with [H₂O] (rho = 0.449, p < 0.001). Subgroup analysis revealed a significant correlation between serum VEGF and [H2O] in oliguric patients (rho = 0.532, p = 0.003). Multiple regression analysis determined the independent effect of serum VEGF on [H₂O] (standardized coefficient = 0.281, p = 0.038).

CONCLUSIONS

In severe sepsis, oliguria relates to higher positive fluid balance, lower tissue perfusion and oxygenation, and progressive tissue fluid accumulation. Elevated serum VEGF is associated with worsening tissue perfusion and oxygenation and independently affects tissue fluid accumulation.

Combination Use of First-Line Afatinib and Proton-Pump Inhibitors Reduces Overall Survival Among Patients with EGFFR Mutant Lung Cancer

Purpose

Previous retrospective studies reported that proton-pump inhibitors (PPIs) may decrease the efficacy of first-generation epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) including gefitinib and erlotinib. Afatinib had a wider soluble pH range, with possible fewer interactions with antacids. However, clinical data were limited. Thus, this study aimed to evaluate the negative impact of PPIs on afatinib.

Patients and Methods

This retrospective cohort study included patients who are newly diagnosed with non-small cell lung cancer (NSCLC) from 2014 to 2019 using the Chang Gung Research Database. We identified patients who were treated with first-line afatinib and analyzed the association between the PPI and afatinib treatment outcomes.

Results

A total of 1418 patients were treated with first-line afatinib and followed up for 6 years. First-line afatinib was administered to 918 eligible patients, and 330 had afatinib with PPIs. The combination use of PPIs and afatinib significantly decreased the overall survival (OS) compared with that of patients using afatinib only (median OS: 33.2 and 25.1 months, p < 0.01) and multivariate analyses (Combination use: hazard ratio: 1.29; 1.05-1.59, p = 0.01). The percentages of patients who were able to receive 2nd line therapy also significantly decreased in afatinib with PPI cohort.

Conclusion

The concurrent use of PPIs was associated with lower OS in patients with EGFR-mutant lung cancer under the first-line afatinib treatment but not associated with TTF.

Clinical Impact of Epidermal Growth Factor Receptor Tyrosine Kinase Inhibitor Associated Clostridioides difficile Infection Among Patients with Lung Cancer

Aim

Epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKIs)-associated Clostridioides difficile infection (CDI) among lung cancer patients have been reported in case reports and adverse events reporting system databases in the United States and Japan, but clinical data remained insufficient. This study aims to evaluate CDI in lung cancer patients receiving EGFR-TKIs.

Methods

We conducted a retrospective cohort study using multi-institutional electronic medical records database. We included patients aged older than 20 years diagnosed with lung cancer and treated with EGFR-TKIs (gefitinib, erlotinib, afatinib). We defined EGFR-TKI initiation date as the index date and occurrence of diarrhea with CDI or without CDI as the event date. We followed patients from the index date until the event date, ICU admission, death, or 12/31/2019.

Results

We included 2242 diarrhea patients, 51 were EGFR-TKI with CDI cohort, and 2191 were diarrhea without CDI cohort. Patients who were concurrently taking antibiotics (hazard ratio [HR], 3.30; 95% CI, 1.67-6.5) and systemic steroids (HR, 4.9; 95% CI, 2.65-9.06) had an increased risk of CDI. First-generation EGFR-TKIs tended to be associated with an increased risk of CDI compared with afatinib (HR, 1.81, 95% CI, 0.94-3.47). EGFR-TKI with CDI had a higher ICU admission rate (HR, 3.42, 95% CI, 1.98-5.91) and mortality rate (HR, 2.34, 95% CI, 1.67-3.28) than diarrhea without CDI.

Conclusion

Patients with CDI had higher ICU admission rates and mortality rates than those without CDI. Concurrent use of antibiotics and systemic steroids were risk factors for CDI among patients with lung cancer receiving EGFR-TKIs. Afatinib was not associated with a higher risk of CDI than first-generation EGFR-TKIs.

The impacts of bacterial co-infections and secondary bacterial infections on patients with severe influenza pneumonitis admitted to the intensive care units

PURPOSES

This study investigated the prevalence and clinical outcomes of pulmonary bacterial co-infections and secondary bacterial infections in patients with severe influenza pneumonitis.

METHODS

We retrospectively analyzed the data of adult patients with severe influenza pneumonitis admitted to medical ICUs. Bacterial co-infections and secondary bacterial infections were identified. The risk factors of bacterial infection were evaluated. The outcomes of patients regarding co-infection or secondary bacterial infection were analyzed.

RESULTS

We identified 117 critically ill patients with laboratory-confirmed influenza pneumonitis admitted to the medical ICUs. Klebsiella pneumoniae (31.4%) and Staphylococcus aureus (22.8%) were the most identified bacteria in patients with bacterial co-infection. A high proportion of methicillin-resistant Staphylococcus aureus (17.1%) was noted. Liver cirrhosis and diabetes mellitus were the independent risk factors for bacterial co-infection. Acinetobacter baumannii (30.7%) and S. aureus (23.1%) were the most often identified bacteria in patients with secondary bacterial pneumonia. Patients with secondary bacterial infections had a longer duration of mechanical ventilation, and longer ICU and hospital stay.

CONCLUSIONS

High rates of drug-resistant bacterial co-infections and secondary bacterial infections were identified in patients with severe influenza pneumonitis requiring ICU care and were associated with more morbidity in these patients.

Increased tissue water in patients with severe sepsis affects tissue oxygenation measured by near-infrared spectroscopy: a prospective, observational case-control study

Background

Tissue oedema affects tissue perfusion and interferes with the monitoring of tissue oxygenation in patients with severe sepsis. However, the underlying mechanisms remain unclear. We used a wireless near-infrared spectroscopy (NIRS) device that transmits tri-wavelength light to quantify tissue haemoglobin (Hb) and water (H₂O) content. We estimated tissue H₂O in severe sepsis patients and healthy controls, compared their difference, and investigated the correlation of tissue H₂O with systemic haemodynamics and its impact on tissue oxygenation.

Methods

Seventy-seven adult patients with new-onset severe sepsis admitted to the intensive care unit within 72 h and 30 healthy volunteers (controls) were enrolled. The NIRS device was placed on the participant’s leg to estimate the relative tissue concentrations of oxy-Hb ([HbO₂]), deoxy-Hb ([HbR]), total Hb ([HbT]), and H₂O ([H₂O]) at rest for three consecutive days. Two-sample t-test or Mann-Whitney U test, chi-square test, and generalised estimating equations (GEEs) were used for comparisons.

Results

In severe sepsis patients, the [H₂O] in the anterior tibia was higher [mean (standard deviation, 95% confidence interval), 10.57 (3.37, 9.81–11.34) vs. 7.40 (1.89, 6.70–8.11)] and the [HbO₂], [HbT], and tissue Hb oxygen saturation (StO₂) were lower [0.20 (0.01, 0.20–0.20) vs. 0.22 (0.01, 0.22–0.23), 0.42 (0.02, 0.42–0.43) vs. 0.44 (0.02, 0.44–0.45), and 47.25% (1.97%, 46.80–47.70%) vs. 49.88% (1.26%, 49.41–50.35%), respectively] than in healthy controls in first-day measurements. GEE analysis revealed significant differences in [H₂O], [HbO₂], [HbT], and StO₂ between groups over three consecutive days (all P≤0.001). In addition, [HbO₂] and StO₂ levels gradually decreased over time in the patient group. A negative correlation was observed between [H₂O] and [HbO₂] and StO₂, which became more obvious over time (day 1: r=−0.51 and r=−0.42, respectively; both P<0.01; day 3: r=−0.67 and r=−0.63, respectively, both P<0.01). Systolic arterial pressure was positively related to [H₂O] (r=0.51, P<0.05, on day 1) but was not associated with tissue oxygenation parameters.

Conclusions

NIRS can be used to quantify tissue H₂O. Severe sepsis patients have increased tissue H₂O, which responds to changes in arterial blood pressure and affects tissue oxygenation.

Stabilization of blood methylmalonic acid level in methylmalonic acidemia after liver transplantation

Methylmalonic acidemia with complete mutase deficiency (mut(0) type) is an inborn error of metabolism with high mortality and morbidity. LT has been suggested to be a solution to this disease, but elevation of urinary and blood MMA was still observed after LT. In this study, we measured dry blood spot MMA and its precursor propionyl-carnitine (C3-carnitine) for mut(0) patients. The results revealed that when C3-carnitine rose during metabolic stress, MMA rose exponentially (up to 1000 micromol/L) in patients who did not undergo LT. In patients who underwent LT, MMA rose to 100-200 micromol/L when C3-carnitine reached 10-20 micromol/L. However, when C3-carnitine rose further to 40-50 micromol/L, MMA levels just stayed put. Therefore, LT stabilized blood MMA level, though there might be a threshold for blood MMA clearance by the donor liver. This finding should be critical to understand the long-term outcome for LT in methylmalonic acidemia.

Do patients with acute liver failure have a better chance to receive liver grafting?

OBJECTIVE

Patients with acute hepatic failure (AHF) were always given first priority on the transplant waiting list. We investigated whether AHF patients will deprive other patients on the waiting list of the chance of liver transplantation (LTx).

METHODS AND RESULTS

From January 1999 to March 2003, a total of 423 patients were on the transplant waiting list at the National Taiwan University Hospital. Sixty-five of the patients had AHF caused by hepatitis-B-related disease (HBV, n = 52, 80%), Wilson disease (n = 3, 4.6%), drug-induced AHF (n = 3, 4.6%), and other causes (n = 7, 10.8%).Thirty-three patients died and 16 survived by medical treatment. Two received LTx abroad and 14 underwent LTx at our hospital (7 living-related; 7 cadaver). A total of 140 patients died while waiting for a transplant during the period studied. Of them, 107 were among 358 non-AHF patients (30%), and time-to-death interval was 133 +/- 175 days (median: 62); 33 were among 65 AHF patients (51%); time to death was 19 +/- 28 days (median: 8). There were 35 cadaver donor livers available during the period; 28 of 358 non-AHF patients (7.8%), and 7 of 65 AHF patients (10.7%) received cadaveric LTx. Their waiting time totaled 342 +/- 316 and 12 +/- 9 days, respectively (P < .0001).

CONCLUSION

Most AHF patients died unless they received liver grafts. Even with a higher priority assigned to them, AHF patients still have little chance to get a cadaver donor liver in Taiwan, and non-AHF patients have an even slimmer chance. Therefore, we need to encourage liver donation from living-related donors.

Thermodynamic characterization of the human acidic fibroblast growth factor: evidence for cold denaturation

The thermodynamic parameters characterizing the conformational stability of the human acidic fibroblast growth factor (hFGF-1) have been determined by isothermal urea denaturation and thermal denaturation at fixed concentrations of urea using fluorescence and far-UV CD circular dichroism (CD) spectroscopy. The equilibrium unfolding transitions at pH 7.0 are adequately described by a two-state (native <--> unfolded state) mechanism. The stability of the protein is pH-dependent, and the protein unfolds completely below pH 3.0 (at 25 degrees C). hFGF-1 is shown to undergo a two-state transition only in a narrow pH range (pH 7.0-8.0). Under acidic (pH <6.0) and basic (pH >8.0) conditions, hFGF-1 is found to unfold noncooperatively, involving the accumulation of intermediates. The average temperature of maximum stability is determined to be 295.2 K. The heat capacity change (DeltaC(p)()) for the unfolding of hFGF-1 is estimated to be 2.1 +/- 0.5 kcal.mol(-1).K(-1). Temperature denaturation experiments in the absence and presence of urea show that hFGF-1 has a tendency to undergo cold denaturation. Two-dimensional (1)H-(15)N HSQC spectra of hFGF-1 acquired at subzero temperatures clearly show that hFGF-1 unfolds under low-temperature conditions. The significance of the noncooperative unfolding under acidic conditions and the cold denaturation process observed in hFGF-1 are discussed in detail.

92% pump depletion in a continuous-wave one-pump fiber optical parametric amplifier

Theory shows that near-complete pump depletion can be obtained in uniform fiber-optic parametric amplifiers (OPA's) for a particular phase-matching condition. We have demonstrated 92% pump depletion in a cw fiber OPA, with a 200-mW pump at 1560 nm in an 11-km-long dispersion-shifted fiber.

Induction of steady-state blood alcohol levels: application to the study of within-session alcohol tolerance in rats

BACKGROUND

The study of within-session alcohol tolerance in the rat has been hampered by methodological difficulties related to the measurement of dependent variables at predictable blood alcohol concentrations (BAC) during a single session of alcohol exposure. This study characterizes a method for maintaining steady-state blood alcohol levels over several hours in the rat, referred to as the "alcohol clamp."

METHODS

Wistar rats were implanted with an indwelling catheter in the carotid artery for blood sampling and another in the external jugular vein for alcohol infusion. To clamp BAC at a predetermined level, rats first were infused with a priming dose of alcohol to establish the desired or "target" BAC, followed by a continuous infusion of alcohol at a rate equal to that of alcohol metabolism in the rat. This maintained BAC at a constant level over time. BACs of 100, 200, or 300 mg% were maintained over several hours in separate groups of rats. The alcohol clamp was applied to the study of acute (within-session) alcohol tolerance in rats selectively bred for high and low alcohol drinking. Alcohol-induced hypothermia was used to index tolerance, and within-session alcohol tolerance was defined as a return of body temperature toward baseline during the course of the alcohol infusion while BAC was maintained at a constant level.

RESULTS

The continuous alcohol infusion procedure maintained BAC in a steady state throughout the 3 hr alcohol infusion session at each of the three target BAC levels. Alcohol infusion induced a drop in body temperature, followed by a return of temperature toward baseline during the course of infusion, which indicated the development of within-session alcohol tolerance.

CONCLUSIONS

The continuous alcohol infusion procedure (alcohol clamp) maintained BAC in a steady state, both within and between subjects, across a wide range of blood alcohol levels. The alcohol clamp appears to be a useful tool for subsequent studies of within-session alcohol tolerance in the rat.

Endothelin-1 protects astrocytes from hypoxic/ischemic injury

Under pathological conditions such as ischemia (I), subarachnoid hemorrhage, and Alzheimer's disease, astrocytes show a large increase in endothelin (ET) -like immunoreactivity. However, it is not clear whether ET is protective or destructive to these cells during brain injury. Using astrocytes from ET-1-deficient mice, we determined the effect of ET-1 on these cells under normal, hypoxic (H), and hypoxic/ischemic (H/I) conditions. Under normal culture conditions, astrocytes from wild-type and ET-1-deficient mice showed no difference in their morphology and cell proliferation rates. ET-3 and ETA receptor mRNAs were up-regulated whereas ETB receptor mRNA was down-regulated in ET-1-deficient astrocytes, suggesting that ET-1 and ET-3 may complement each other's functions and that the expressions of these endothelins and their receptors are regulated by a complex feedback mechanism. Under H and H/I conditions, ET-1 peptide and mRNA were up-regulated in wild-type astrocytes, and the astrocytes without ET-1 died faster than the wild-type astrocytes, as indicated by greater efflux of lactate dehydrogenase. The present study suggests that astrocytes without ET-1 are more vulnerable to H and H/I injuries and that the up-regulation of astrocytic ET-1 is essential for the survival of astrocytes.

Hepatic portal vein gas following blunt colon injury: report of a case

Blunt colon injuries sometimes result in signs of peritoneal irritation requiring exploratory laparotomy. More frequently there are no specific symptoms, and this leads to a delay in diagnosis and management. Some imaging studies point to blunt colon injury, but gas in both the hepatic portal and mesenteric veins has rarely been reported. Hepatic portal venous gas (HPVG) is a rare roentgenographic picture, and its presence usually represents a serious intra-abdominal catastrophe. Computed tomography and plain abdominal X ray in a 52-year-old man with blunt abdominal injury showed significant gas in the portal venous system and pneumatosis intestinales of the ascending colon. Exploratory laparotomy revealed segmental necrosis of the transverse colon in front of the vertebrae. The presence of HPVG may have been due to mucosal disruption, vascular compromise or prolonged increased intra-abdominal pressure. Its presence in patients with blunt abdominal trauma suggests the possibility of bowel injury. Surgical exploration should be considered when HPVG is noted on roentgenographic studies.

Sequence analysis of the Aspergillus nidulans pectate lyase pelA gene and evidence for binding of promoter regions to CREA, a regulator of carbon catabolite repression

The nucleic acid and deduced amino-acid sequences of the pectate lyase gene (pelA) from Aspergillus nidulans are presented. The pelA gene contains two short introns, 68 and 49 bp in length, and encodes a peptide of 326 amino acids. Five transcriptional start sites are clustered between 65 and 79 bp upstream of the start codon as determined by primer extension. Comparison of the amino-acid sequences of pectate or pectin lyases from bacteria, fungi and plants revealed less than 30% overall identity. However, five regions within these enzymes, in particular domains associated with the active site, are highly conserved with amino-acid similarities greater than 50%. Phylogenetic analysis using the principle of parsimony (PAUP 3.1.1) showed that pelA is most closely related to pectate lyases from plants rather than pectin lyases from other fungi. Previously, pelA was shown to be induced by polygalacturonic acid and repressed in the presence of preferred carbon sources, such as glucose. Gel mobility shift analysis indicates that a PstI-SphI fragment from the pelA promoter binds to a fusion protein composed of the N-terminal part of CREA, a protein involved in carbon catabolite repression, and glutathione-S-transferase. This result suggests CREA may contribute to the regulation of pelA expression.

Kinetics of proteolysis of hog gastric mucin by human neutrophil elastase and by Pseudomonas aeruginosa elastase

Human neutrophil and Pseudomonas aeruginosa elastases were compared for their ability to degrade hog gastric mucin, which was used as a model substrate. P. aeruginosa elastase was more active than neutrophil elastase, and 2 to 10 peptide bonds were hydrolyzed within 5 min. The results demonstrate that both elastases degrade mucins actively at concentrations comparable to physiological levels of neutrophil elastase, which raises the possibility that proteolysis of mucins may be one mechanism of damage during chronic infection and inflammation of the respiratory tract.