Prevalence of Giardia duodenalis among Asian children: a systematic review and meta-analysis

Giardia duodenalis is one of the major causes of diarrhea among children. We performed a systematic review and meta-analysis to assess the prevalence of G. duodenalis and associated risk factors among Asian children. We searched online databases (PubMed, Scopus and Web of Science) and Google Scholar search engine for studies published from 1 January 2000 to 15 March 2022 that measured the prevalence of G. duodenalis among Asian children. Accordingly, the pooled prevalence and 95% CIs were estimated using a random-effects meta-analysis model for the included studies. A total of 182 articles from 22 Asian countries met the inclusion criteria. The pooled prevalence of G. duodenalis infection among Asian children was estimated as 15.1% (95% CI 14.1 to 16%). The highest and lowest pooled prevalence values of G. duodenalis infection were estimated for Tajikistan and China as 26.4% (95% CI 22.9 to 30%) and 0.6% (95% CI 0.001 to 1.02%), respectively. The infection had a higher prevalence in males than in females (OR=1.24; 95% CI 1.16 to 1.31; p<0.001), which was statistically significant. Giardiasis is common among Asian children, hence, a prevention and control scheme of this protozoan in children should be considered by health officials and health policymakers, especially in Asian countries where the prevalence is highest.

Global Seroprevalence of Toxocara spp. in Children: A Systematic Review and Meta-analysis

BACKGROUND

In the present study, we performed a systematic review and meta-analysis to assess the global and regional seroprevalence of Toxocara spp. and associated risk factors among children.

METHODS

The present systematic review and meta-analysis was followed based on the Preferred Reporting. Items for Systematic Reviews and Meta-analyses (PRISMA) protocol. We searched the online databases (PubMed, Scopus, and Web of Science) and Google Scholar search engine for studies that measured seroprevalence of Toxocara spp. among children, published between 1 January 2000 and 15 January 2022. Accordingly, the pooled seroprevalence and 95% confidence intervals (CI) were estimated using a random-effects meta-analysis model.

RESULTS

A total of 65 articles from 22 countries met the inclusion criteria. The global seroprevalence of Toxocara spp. infection among children was estimated as 25% (95% CI 22-29). Meta-regression analysis showed that the type of population studied (p = 0.002) and year of publication (p = 0.044) it may be the source of heterogeneity. The highest and lowest pooled seroprevalence of Toxocara spp. infection were estimated in Thailand and Colombia as 58.2% (95% CI 50.9-65.5) and 7.04% (95% CI 3.05-11.3), respectively. Male gender was associated with a higher risk of Toxocara spp. compared to females, and this association was statistically significant (OR = 1.24; 95% CI 1.09-1.41, p = 0.001). However, residing in rural areas did not show a statistically significant increase in risk compared to living in urban areas (OR = 1.39; 95% CI 0.88-2.21, p = 0.143).

CONCLUSION

Toxocariasis is common among children, hence, prevention and control scheme of this helminth in children should be considered by health officials and health policymakers, especially in developing countries, where seroprevalence is highest.

Prevalence of intestinal parasitic infections in patients with diabetes: a systematic review and meta-analysis

Patients with diabetes are at an increased risk of intestinal parasitic infections (IPIs). We evaluated the pooled prevalence and OR of IPIs in patients with diabetes through a systematic review and meta-analysis. A systematic search was performed using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) protocol for studies reporting IPIs in patients with diabetes through 1 August 2022. The collected data were analyzed using comprehensive meta-analysis software version 2. Thirteen case-control studies and nine cross-sectional studies were included in this study. The overall prevalence of IPIs in patients with diabetes was calculated to be 24.4% (95% CI 18.8 to 31%). Considering the case-control design, the prevalence of IPIs in case (25.7%; 95% CI 18.4 to 34.5%) was higher than controls (15.5%; 95% CI 8.4 to 26.9%) and a significant correlation was observed (OR, 1.80; 95% CI 1.08 to 2.97%). Moreover, a significant correlation was seen in the prevalence of Cryptosporidium spp. (OR, 3.30%; 95% CI 1.86 to 5.86%), Blastocystis sp. (OR, 1.57%; 95% CI 1.11 to 2.22%) and hookworm (OR, 6.09%; 95% CI 1.11 to 33.41%) in the cases group. The present results revealed a higher prevalence of IPIs in patients with diabetes than in controls. Therefore, the results of this study suggest a proper health education program to preventing measures for the acquisition of IPIs in patients with diabetes.

Latent infections, coronavirus disease 2019 and psychiatric disorders: The friend of my enemy

Recent reports revealed an increased rate of hospitalization and mortality of coronavirus disease 2019 (COVID-19) among patients with psychiatric disorders. On the other hand, there is a link between latent infections, including Toxoplasma gondii, herpes simplex virus type 1 (HSV-1) and cytomegalovirus (CMV) with psychiatric disorders. We individually assessed data regarding 1) the mortality rate of COVID-19 among individuals with psychiatric disorders; 2) the association of latent infections in COVID-19 patients and 3) the association between latent infections and psychiatric disorders. We developed the hypothesis that latent infection could increase the risk of severe COVID-19 among patients with psychiatric disorders. Cumulative evidence proposed that infection with toxoplasmosis, CMV and HSV-1 could increase the risk of severe acute respiratory syndrome coronavirus 2 (SARS-Co-V2) infections among patients with psychiatric disorders probably by induction of hyperinflammatory conditions. These infections are also associated with hyperinflammation and T cell exhaustion, which has also been observed in both schizophrenia and COVID-19. This hypothesis provides new insights into the role of latent infections in increasing the mortality rates of COVID-19 among individuals with psychiatric disorders. Strategies for screening, early diagnosis and treatment of these infections could be recommended for COVID-19 patients with a background of psychiatric disorders.

Sufficient Sleep, Time of Vaccination, and Vaccine Efficacy: A Systematic Review of the Current Evidence and a Proposal for COVID-19 Vaccination

Introduction: The emergence of the novel Coronavirus Disease 2019 (COVID-19) sparked an unprecedented effort to develop effective vaccines against the disease. Some factors may boost the vaccine efficacy, including sufficient sleep and morning vaccination. We aimed to conduct a rapid systematic review to summarize data regarding the association between sleep and time of vaccination with immunity after vaccination. Materials and Methods: The systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) protocol, and three databases (PubMed, Web of Science, and Scopus) were searched up to March 12, 2022. Results: Eight studies were included regarding the sleep and immune response after vaccination, of them, five studies were on influenza, two studies on hepatitis A (HAV), and one study on hepatitis B. Accordingly, six out of eight studies found a positive correlation between sleep and immune response after vaccination. Regarding the time of vaccination, seven studies were eligible to be included (two studies on influenza, one study on HAV and influenza, one study on BCG, one study on hexavalent vaccine, and two studies on SARS-CoV-2 vaccine). Among them, four out of seven studies (including a study on SARS-CoV-2 inactivated vaccine) reported the priorities of morning versus afternoon vaccination regarding antibody production and immune response after vaccination. Conclusion: Taken together, cumulative evidence suggests that sufficient sleep and vaccination in the morning could enhance the immune response after vaccination. Hence, modulating the time of vaccination and sufficient sleep could a be simple and applicable strategy for increasing vaccine efficacy. Future studies could be performed with SARS-CoV-2 vaccines to investigate the effects of time of vaccination and sufficient sleep on COVID-19 vaccine efficacy.

Study of the K-S distance on skulls from different modern populations for sex and ancestry determination

In forensic science determination of the origin and sex of skeletal remains is an important task for identification purposes. In this study we investigated the krotaphion-sphenion distance (K‑S distance) in the pterion region of German, Euro-American, African-American and Rwandan skulls of modern individuals from the nineteenth to the twenty-first century to look for statistically significant differences in sex and ancestry. We found a statistically significant sex-specific difference in the K‑S distance, which was greater in male skulls than in female skulls for both sides of the skull. Our study also showed that there is a statistically significant difference in the K‑S distance between the four populations studied. Landmarks and morphometric parameters measured in our investigations, which were not used for the present examination were provided to the software program Fordisc for its reference data to enhance the range of its usability for identification of unknown skulls or partial skulls of European individuals.

Prevalence and severity of Coronavirus disease 2019 (COVID-19) in Transfusion Dependent and Non-Transfusion Dependent β-thalassemia patients and effects of associated comorbidities: an Iranian nationwide study

BACKGROUND

Coronavirus disease 2019 (COVID-19) outbreak is a global and challenging disease that is accompany with mortality and morbidity.

AIM OF STUDY

We evaluated the prevalence and the impact of comorbidities in thalassemia Iranian patients affected by COVID-19.  Methods: A multicenter, retrospective, cross-sectional study was conducted across all comprehensive thalassemia centers in Iran, from January to June 15th, 2020.

RESULTS

Forty-three confirmed COVID-19 thalassemia patients (32 TDT, and 11 NTDT) were detected. The mean age of patients was 35.3 ± 11.5 years (range 9 - 67); 21 females and 22 males. Overall, 78.1% of TDT and 90.9% of NTDT patients were complicated with at least one comorbidity (P: 0.656). The overall mortality rate of thalassemia patients with COVID-19 was 18.6% while 27.3% was in NTDT patients compared to 15.6% in TDT patients (P:0.401). The dead group had a non-significant higher frequency of endocrinopathies compared to the recovered group (62.5% versus 45.7% P:0.457). Ten female thalassemia patients with positive COVID-19 had hypogonadism, six patients were receiving hormone replacement therapy and all of them recovered (zero death) compared to two deaths from 4 patients who were not receiving hormone replacement therapy (P:0.133). Furthermore, the prevalence of COVID-19 in NTDT patients was significantly higher than the general population (45 per 10,000 versus 22.29 per 10,000 respectively, P:0.018) while the prevalence of TDT was almost similar to the normal population (P:0.539). The mortality rate of COVID-19 was 4.71% in the normal Iranian population compared to 18.6% in β-thalassemias (P: <0.001) at the same date.

CONCLUSIONS

It is important to acknowledge that β-thalassemia patients, especially young adults/adults, have a chronic condition which may contribute to increase susceptibility to SARS-CoV-2 infection. A higher susceptibility to the infection was observed in patients with NTDT and in untreated hypogonadal female thalassemic patients. However, to confirm these data, more accurate designed studies are needed.

Serum Ferritin Levels Correlation With Heart and Liver MRI and LIC in Patients With Transfusion-Dependent Thalassemia

BACKGROUND

Iron-loaded cardiac complication is the essential cause of mortality in patients with thalassemia. Early detection and treatment of cardiac over-load can reduce mortality.

OBJECTIVES

The current study aimed to evaluate the relationship between serum ferritin levels and T2* magnetic resonance imaging (MRI) of heart and liver and liver iron concentration (LIC) to diagnose iron over load in countries with limited access.

PATIENTS AND METHODS

In the current cross-sectional study, 85 Iranian patients with thalassemia with the mean age of 22.7 ± 7 years were randomly selected. All patients were on regular blood transfusion. Echocardiography of heart and liver T2* MRI, determination of serum ferritin levels, and LIC were performed in all subjects at the same time. The correlation of serum ferritin levels with T2*MRI of heart and liver, and LIC was assessed. P value < 0.05 was considered statistically significant.

RESULTS

Abnormal myocardial iron load (T2* MRI < 20 ms) was detected in 58% of the patients and among whom, 36% had severe myocardial iron load (T2* MRI < 10 ms). Median and interquartile range of serum ferritin levels were 1434 and 2702 respectively in patients with thalassemia. Serum ferritin levels showed a statistically significant positive correlation with LIC (rs = 0.718, P < 0.001) and significant negative correlation with T2* Heart (rs = -0.329, P = 0.002), and T2* Liver (rs = -0.698, P < 0.001). However, Ejection fraction was not significantly correlated with serum ferritin levels in the patients (P = 0.399).

CONCLUSIONS

Serum ferritin levels can be used to diagnose iron over-load in patients with thalassemiaas an alternative method in areas where T2* MRI is not available.

The pathological presentations of neuro-Behçet disease: a case report and review of the literature

OBJECTIVES

To report the neuropathologic features of a patient with neuro-Behçet disease and to review the literature.

METHODS

Herein, we describe a 35-year-old male who fulfills the International Study Group criteria for Behçet disease.

RESULTS

The patient developed headache and hemiparesis in a subacute course. His neurologic examination revealed an altered level of consciousness and unilateral corticospinal signs. The brain magnetic resonance imaging (MRI) showed areas with increased signal intensity in the basal ganglia and cerebral peduncles in T2-weighted and fluid-attenuated inversion recovery (FLAIR) images. Cerebrospinal fluid (CSF) analysis showed mononuclear pleocytosis but normal protein and glucose levels. After his death, the patient's autopsy revealed a perivascular infiltration of mononuclear inflammatory cells, most prominently in basal ganglia, midbrain, and thalamic regions and the subarachnoid space, consistent with presentations of neuro-Behçet disease.

CONCLUSION

Pathologic findings of central nervous system involvement in Behçet disease mainly include perivascular infiltration with lymphocytes, neutrophils and rarely, eosinophils, with or without signs of necrosis. The most common sites of brain involvement include the brainstem and basal ganglia. Nonetheless, other areas can also be involved.

Von Hippel-Lindau gene mutation status is associated with a dichotomous response in primary and metastatic tumors in patients receiving bevacizumab and erlotinib for metastatic renal cell carcinoma

15522

Background: A single arm phase II study is underway evaluating the safety and clinical benefit of presurgical bevacizumab and erlotinib in the management of patients with untreated conventional renal cell carcinoma (RCC). It is not known how the presence or absence of von Hippel Lindau (VHL) mutations affect the response to therapy in the primary or metastatic site, and whether VHL mutational status is predictive for either. Methods: Patients enrolled had conventional RCC, measurable metastatic disease, a primary tumor in place, no prior systemic therapy, a PS of 0 or 1 and no brain metastases. A total of 35 patients were enrolled as of January 8, 2007. Patients were treated with bevacizumab for 4 cycles and erlotinib for 8 weeks, and underwent cytoreductive nephrectomy at week 10 (4 weeks after the last dose of bevacizumab). A VHL gene mutation and methylation analysis was completed on nephrectomy specimens from the first 18 evaluable patients. Patients were grouped according to the presence or absence of functional VHL gene inactivation (mutation and/or methylation). Two-sample T-test and Fisher’s exact test were performed. Results: Ten patients (55%) demonstrated either VHL mutation or methylation ( table 1 ). Patients with no VHL gene inactivation demonstrated more robust primary tumor shrinkage, but did not demonstrate partial responses (PRs). Table 1 . Conclusions: These findings, although preliminary, suggest a dichotomous response in the primary and metastatic disease sites according to VHL functional status. Ongoing evaluation of new treatment strategies using antivascular/targeted agents in RCC may benefit from molecular stratification.

[Table: see text]

No significant financial relationships to disclose.

Adjuvant thalidomide improves disease specific survival for patients with renal cell carcinoma at high risk for relapse following surgery

14586

Background: Observation is the standard of care for locally advanced renal cell carcinoma (RCC) after surgery. No adjuvant therapy for RCC exists. Thalidomide has shown activity in metastatic RCC. We studied thalidomide in the adjuvant setting for patients with locally advanced RCC. Methods: This phase III trial has enrolled 46 patients to date. All patients underwent resection of all disease. Eligible patients included T2N0M0 grade 3–4, T3a-cN0M0, T4N0M0, TanyN1–2M0, and TanyN0M0 bilateral disease completely resected. All RCC histologies were included. Patients were randomized to observation or thalidomide, 300 mg daily for 2 years. Dose reductions were allowed for toxicity. The primary endpoint was recurrence free survival. Secondary endpoints were disease specific survival and toxicity. Results: Twenty-three patients randomized to thalidomide and 23 were observed. In the thalidomide arm, one patient refused therapy and two stopped within one month due to toxicity. Only 1 patient tolerated therapy for 2 years without dose reduction. With a median follow-up of 18 months, there were 6 recurrences and 5 disease related deaths in the observation arm and 7 recurrences and 2 disease related deaths in the thalidomide arm. Using an intent to treat principle in our multivariate analysis, adjusting for grade, stage, and nodal status, we noted no significant difference in recurrence free survival between observation (mean 31 months; median not reached (NR)) and the thalidomide arm (mean 24.7 months; median NR) (Hazard ratio = 1.04, 95% CI 0.34 to 3.14, p = 0.945). Interestingly, disease specific survival was significantly better in the thalidomide arm (mean 40.1 months; median NR), as compared to the observation arm (mean 37.1 months; median NR) (Hazard ratio = 0.086, 95% CI 0.008 to 0.981, p = 0.048). Conclusions: In this limited experience with surgically resected RCC at high risk for relapse, thalidomide did not impact time to recurrence but significantly improved disease specific survival in the adjuvant setting. Despite this clinical benefit, significant toxicity limited tolerability of the drug. These data suggest that derivatives of thalidomide, with different toxicity profiles, might warrant testing in the adjuvant setting for RCC.

No significant financial relationships to disclose.

Cytoreductive nephrectomy for metastatic renal cell carcinoma in the presence of nonconventional histology

14535

Background: While randomized trials show a survival benefit for cytoreductive nephrectomy in the setting of metastatic conventional (clear cell) renal cell carcinoma (mRCC), the benefit of cytoreductive surgery for patients with mRCC of nonconventional histology (papillary, chromophobe, unclassified) is unknown. We evaluated our experience with cytoreductive nephrectomy for nonconventional mRCC at M. D. Anderson. Methods: From 1990–2004, 464 patients with mRCC underwent cytoreductive nephrectomy; of these, 89 patients had nonconventional mRCC and form the basis of this report. The remaining 375 patients with conventional mRCC formed a comparative group. Overall survival (OS) and disease-specific survival (DSS) data were evaluated by Kaplan and Meier analysis, with univariate and multivariate log rank tests. Results: Compared to patients with conventional histology, patients with nonconventional mRCC were younger (p < 0.045), more likely to have nodal metastases (p < 0.0001), and more likely to have sarcomatoid dedifferentiation (21.2 versus 13.2%, p = 0.056). In multivariate analysis, the median survival for nonconventional histology was significantly worse than for conventional mRCC (11.1 versus 19.5 months, p = 0.0081), even after adjusting for stage, grade, performance status, age, and presence of sarcomatoid dedifferentiation. Although positive nodal status was associated with a decreased survival in nonconventional histology (p < 0.0001) in our multivariate analysis, even node negative patients demonstrated a worse survival when compared to those with conventional histology (p = 0.03). Interestingly, patients with nonconventional mRCC who had complete resection of their retroperitoneal nodal metastases with cytoreduction showed a trend towards improved survival, as has been reported in patients with conventional mRCC and nodal disease. Conclusions: Patients with nonconventional mRCC have a higher incidence of nodal metastases and demonstrate a worse prognosis than those with conventional histology, who undergo cytoreductive surgery. Aggressive cytoreduction with removal of all nodal disease may improve outcomes. More effective systemic therapies are needed to improve upon the results seen with aggressive surgery.

No significant financial relationships to disclose.

Nonessential amino acids are not necessary to stimulate net muscle protein synthesis in healthy volunteers

The present study was performed to test the hypothesis that orally administered essential amino acids, in combination with carbohydrate, will stimulate net muscle protein synthesis in resting human muscle in vivo. Four volunteers ingested 500 mL of a solution containing 13.4 g of essential amino acids and 35 g sucrose (EAA). Blood samples were taken from femoral arterial and venous catheters over a 2-hour period following the ingestion of EAA to measure arteriovenous concentrations of amino acids across the muscle. Two muscle biopsies were taken during the study, one before administration of the drink and one approximately 2 hours after consumption of EAA. Serum insulin increased from normal physiologic levels at baseline (9.2 +/- 0.8 microU/mL) and peaked (48 +/- 7.1 microU/mL) 30 minutes after EAA ingestion. Arterial essential amino acid concentrations increased approximately 100 to 400% above basal levels between 10 and 30 minutes following drink ingestion. Net nitrogen (N) balance changed from negative (-495 +/- 128 nmol/mL) prior to consumption of EAA to a peak positive value (416 +/- 140 nmol/mL) within 10 minutes of ingestion of the drink. EAA resulted in an estimated positive net N uptake of 307.3 mg N above basal levels over the 2-hour period. Muscle amino acid concentrations were similar prior to and 2 hours following ingestion of EAA. We conclude that ingestion of a solution composed of carbohydrates to stimulate insulin release and a small amount of essential amino acids to increase amino acid availability for protein synthesis is an effective stimulator of muscle protein anabolism.

Analysis of surgical success in preventing recurrent acute exacerbations in chronic pancreatitis

OBJECTIVE

To determine whether surgical intervention prevents recurrent acute exacerbations in chronic pancreatitis (CP).

SUMMARY BACKGROUND DATA

The primary goal of surgical intervention in the treatment of CP has been relief of chronic unrelenting abdominal pain. A subset of patients with CP have intermittent acute exacerbations, often with increasing frequency and often unrelated to ongoing ethanol abuse. Little data exist regarding the effectiveness of surgery to prevent acute attacks.

METHODS

From 1985 to 1999, all patients identified with a diagnosis of CP were recruited to participate in an ongoing program of serial clinic visits and functional and clinical evaluations. Patients were offered surgery using standard criteria. Data were gathered regarding ethanol abuse, pain, narcotic use, and recurrent acute exacerbations requiring hospital admission before and after surgery. Patients were broadly categorized as having severe unrelenting pain alone (group 1), severe pain with intermittent acute exacerbations (group 2), and intermittent acute exacerbations only (group 3).

RESULTS

Two hundred fifty-nine patients were recruited. One hundred eighty-five patients underwent 199 surgical procedures (124 modified Puestow procedure [LPJ], 29 distal pancreatectomies [DP], and 46 pancreatic head resections [PHR; 14 performed after failure of LPJ]). There were no deaths. The complication rate was 4% for LPJ, 15% for DP, and 27% for PHR. Ethanol abuse was causative in 238 patients (92%). Mean follow-up was 81 months. There were 104 patients in group 1 (86 who underwent surgery), 71 patients in group 2 (64 who underwent surgery), and 84 in group 3 (49 who underwent surgery). No patient without surgery had spontaneous resolution of symptoms. Postoperative pain relief (freedom from narcotic analgesics) was achieved in 153 of 185 patients (83%) overall: 106 of 124 (86%) for LPJ, 19 of 29 (67%) for DP, and 42 of 46 (91%) for PHR. The mean rate of acute exacerbations was 6.3 +/- 2.1 events per year before surgery in group 2 and 7.8 +/- 1.8 events per year in group 3. After surgery, no acute exacerbations occurred in 42 of 64 (66%) group 2 patients and in 40 of 49 (82%) group 3 patients. The mean number of episodes of acute exacerbation after surgery was 1.6 +/- 2.3 events in group 2 and 1.1 +/- 1.9 events in group 3. Only four patients in group 2 and one patient in group 3 had an equal or increased frequency of attacks after surgery. Preventing attacks was most effective with LPJ (58/64, 91%) and least effective for DP (6/18, 33%).

CONCLUSIONS

Surgical intervention prevents recurrent acute exacerbations. The overall frequency of events was reduced in nearly all patients. Therefore, surgical intervention is indicated in patients with CP whose disease is characterized by recurrent acute exacerbations.

Increased small bowel epithelial turnover in interleukin-1 receptor knockout mice

OBJECTIVE

To determine whether interleukin-1 (IL-1) affects the cellular homeostasis of small bowel mucosa, the authors studied apoptosis and proliferation in small bowel epithelium in two groups of C57 mice: an IL-1 receptor knockout group, and a control wild-type group.

SUMMARY BACKGROUND DATA

Gut mucosal integrity is maintained by a balance of cell proliferation and cell death. Recent reports suggest that IL-1, a proinflammatory cytokine, increases cell death by apoptosis in some epithelial cells.

METHODS

Twenty-four male C57BL6 IL-1 receptor (type I) knockout mice were killed, and small bowel was removed for study. Twenty-four wild-type mice (C57-BL6) served as controls. Body weights, bowel length, and mucosal morphology were examined for phenotypic differences. Apoptosis was quantified by terminal deoxyuridine nick-end labeling (TUNEL) immunohistochemical staining and cellular proliferation by proliferation cell nuclear antigen staining. Whole mucosal protein was analyzed for nuclear factor-kappaB expression. Groups were analyzed by t test.

RESULTS

The absence of IL-1 type I receptor in knockout mice was verified by reverse transcriptase-polymerase chain reaction. IL-1 receptor null mice were larger than wild-type controls, with a longer small bowel; however, the index of small bowel length to total body weight did not differ between groups. The percentage of apoptotic cells was higher in IL-1 receptor null mice than in wild-type mice; the proliferation index also increased. Mucosal height and other measures of mucosal morphology were not different. Genotypic absence of IL-1 receptors was associated with decreased expression of nuclear factor-kappaB in whole mucosal protein extracts.

CONCLUSIONS

Both apoptosis and proliferation increased in gut epithelial cells of mice without IL-1 receptors, suggesting increased cell turnover with no change in net balance. This model represents an opportunity to examine potential mechanisms of gut epithelial turnover in vivo, under both normal conditions and in conditions of mucosal proliferation and atrophy.

A submaximal dose of insulin promotes net skeletal muscle protein synthesis in patients with severe burns

OBJECTIVE

To investigate the hypothesis that a submaximal insulin dose reverses the net muscle catabolism associated with severe burns, and to determine its effects on amino acid kinetics.

SUMMARY BACKGROUND DATA

The authors previously showed that a maximal dose of insulin administered to patients with severe burns promoted skeletal muscle glucose uptake and net protein synthesis. However, this treatment was associated with caloric overload resulting from the large quantities of exogenous glucose required to maintain euglycemia, and hypoglycemia was a potential problem.

METHODS

Thirteen patients were studied after severe burn injury (>60% total body surface area). Patients were randomly treated by standard care (n = 5) or with exogenous insulin (n = 8). Data were derived from an arteriovenous model with primed-continuous infusions of stable isotopes and biopsies of the vastus lateralis muscle.

RESULTS

Net amino acid balance was significantly improved with insulin treatment. Skeletal muscle protein synthesis was significantly greater in the group receiving insulin, whereas muscle protein breakdown was not different between the groups. This submaximal dose of insulin did not affect glucose or amino acid uptake or require a greater caloric intake to avoid hypoglycemia.

CONCLUSIONS

Submaximal insulin can promote muscle anabolism without eliciting a hypoglycemic response.

Cutaneous burn increases apoptosis in the gut epithelium of mice

BACKGROUND

Gut mucosal homeostasis depends on a balance between cell proliferation and cell death. After cutaneous burn injury, gut mucosal weight has been shown to decrease. This decrease in weight was paradoxically associated with an increase in gut proliferative factors. For mucosal weight to decrease in the presence of increased proliferation, there must be an even greater increase in cell death. We postulate that cutaneous burn injury causes an increase in gut epithelial cell death primarily by apoptosis.

STUDY DESIGN

We produced a 30% full-thickness scald burn in the dorsum of anesthetized male C57BL6 mice and collected the proximal small bowel at 12, 24, 36, 48, and 60 hours after injury. Sham burned animals served as controls. Apoptosis and proliferation were measured by immunohistochemical assays (terminal deoxyuridine nick-end labeling for apoptosis and proliferative cell nuclear antigen assay for proliferation). Apoptosis was also measured by ELISA for cytoplasmic histone-associated DNA fragments. Mucosal height was determined on histologic sections. The two groups were compared at each time point using Wilcoxon two-sample test and t-test with Bonferroni's correction where appropriate.

RESULTS

The percentage of apoptotic cells (number of cells stained by terminal deoxyuridine nick-end labeling per 100 villus cells) was significantly higher at 12, 24, and 48 hours after injury. This increase was corroborated by an increase in the ELISA at 12 hours. Proliferation as measured by immunostaining for proliferative cell nuclear antigen significantly increased at 12, 24, 48, and 60 hours. Mucosal height as a gross measure of mucosal atrophy was not different between the groups.

CONCLUSIONS

We have shown an increase in apoptosis coupled with an increase in proliferation after a burn injury. These results imply an increase in cell turnover in the gut epithelial cells after a burn. Impaired bowel function has been demonstrated repeatedly after burn injury, and this increase in cell turnover may be related.

Acute dichloroacetate administration increases skeletal muscle free glutamine concentrations after burn injury

OBJECTIVE

To investigate the hypothesis that the stimulation of pyruvate oxidation by dichloroacetate (DCA) administration would increase the level of intramuscular glutamine in severely burned patients.

SUMMARY BACKGROUND DATA

The level of intramuscular glutamine decreases in response to severe injury, and the rate of intramuscular glycolysis and pyruvate oxidation is elevated. Intramuscular glutamine concentrations have been correlated to muscle protein synthesis.

METHODS

Six studies were conducted on five patients with burns >40% total body surface area. Patients were studied in the fed state during an 8-hour stable isotope infusion. After 5 hours, DCA (30 mg/kg) was administered for 30 minutes.

RESULTS

Analysis of muscle biopsy samples taken at 5 and 8 hours of the study revealed a 32% increase in intracellular glutamine levels after DCA administration. Increased intracellular glutamine concentrations did not affect skeletal muscle protein synthesis as determined by a three-pool arteriovenous model or by the direct incorporation of isotope into skeletal muscle protein. DCA administration resulted in a decrease in plasma lactate but no change in alanine de novo synthesis or intracellular concentration.

CONCLUSIONS

These results suggest that acute DCA administration can increase intramuscular glutamine concentration, but that this acute elevation does not affect muscle protein metabolism.

Effects of therapy with recombinant human growth hormone on insulin-like growth factor system components and serum levels of biochemical markers of bone formation in children after severe burn injury

Burn injury in children is associated with low bone formation and long-term bone loss. Because recombinant human GH (rHGH) may accelerate burn wound healing, and because rHGH increases bone formation and density in GH-deficient patients, we studied the short-term effects of rHGH on bone fomation, reflected by osteocalcin and type I procollagen propeptide levels in a randomized, double-blind, placebo-controlled study. Nineteen patients were enrolled and received either rHGH (0.2 mg/kg.day) or an equal volume of saline. Mean burn size and age were not different between the groups, and test substances were given from admission to time of wound healing (mean: 43 +/- 22 days). At wound healing, serum levels of insulin-like growth factor (IGF)-1 and IGF binding protein (IGFBP)-3 in the rHGH group rose to mean values of 229% and 187% of the respective means of the placebo group (P < 0.025). Serum osteocalcin concentrations remained below normal in both groups, and type I procollagen propeptide levels achieved a low normal level IGFBR-4 levels were twice that of normal on admission and doubled further at wound healing; IGFBP-5 levels were low on admission but rose to normal at wound healing. We conclude that large doses of rHGH were ineffective in improving disordered bone formation despite increasing serum IGF-1 and IGFBP-3. The rHGH-independent rise in serum levels of the inhibitory binding protein IGFBP-4 suggests a mechanism by which improved bone formation is prevented despite successful elevation of IGF-1 and IGFBP-3 in the burned child.

Insulin-like growth factor-I liposomal gene transfer and systemic growth hormone stimulate wound healing

Many of the anabolic effects of growth hormone (GH) act through insulin-like growth factor-I (IGF-I). Systemic administration of GH in combination with IGF-I has been shown to stimulate wound reepithelialization, however, it causes hyperglycemia or hypoglycemia, respectively. We hypothesize that very low doses of IGF-I in a liposome form will have the same positive wound-healing effect when administered locally as the higher doses of GH plus IGF-I given systemically. To test this hypothesis, rats were given a 40% TBSA full-thickness scald injury and received either placebo IGF-I (5.0 mg/kg/day, subcutaneously), IGF-I liposome (0.9 microgram/kg/week, subcutaneously), or a combination of GH and IGF-I, or IGF-I liposomes for 8 weeks. GH in combination with IGF-I showed a significant increase in postburn weight. Wound reepithelialization, measured by computerized planimetry as percentage original wound area, was significantly increased in rats receiving GH plus IGF-I, GH plus IGF-I liposomes, and IGF-I liposomes when compared to sham, or IGF-I (p < 0.05). Results indicate that small doses of IGF-I, delivered in the form of liposomes, are equally effective in increasing burn wound reepithelialization as the higher doses of GH plus IGF-I, or GH plus IGF-I liposomes.

Glutathione, glutathione S-transferase, and transmembrane transport of glutathione conjugate in human neutrophil leukocytes

Glutathione (GSH) conjugation is important in the detoxification of carcinogens and other exogenous electrophilic drugs and chemicals. The conjugation is catalyzed by GSH S-transferase. Neutrophil GSH content was 12.3 +/- 2.5 (mean +/- SD) nmol/10(7) cells, and transferase activity of cytosol preparations was 0.187 +/- 0.035 nmol/min/mg protein with 1-chloro-2,4-dinitrobenzene (CDNB) as substrate. Maximal activity was found at a pH of 7.0 and a temperature of 40 degrees C. Apparent Km of transferase was 1.25 +/- 0.18 mmol/L CDNB, and apparent Vmax was 0.621 +/- 0.22 nmol/min/mg. GSH-CDNB conjugate was quantitated by HPLC in cells and in medium after CDNB exposure. Transport of conjugate from cells to medium increased with CDNB concentration to 50 mumol/L, and kinetic data showed two saturable transport mechanisms with apparent Km of 5.90 mumol/L and 0.265 mumol/L, respectively. Cellular GSH content fell rapidly with CDNB concentration greater than 2.5 mumol/L, and was depleted in a 10-minute incubation at a concentration of greater than 50 mumol/L CDNB. Neutrophils have a significant content of GSH and a significant amount of transferase activity, and transport of GSH conjugate involves two distinct saturable pathways. GSH depletion can be accomplished with a relatively low concentration of an exogenous chemical and could impair the ability of the cells to carry out their phagocytic functions.

Superoxide radical production after phorbol ester stimulation in neutrophils of aged donors

Superoxide anion radical production was studied in purified neutrophils of young and old donors after stimulation with phorbol 12-myristate 13-acetate to determine whether phorbol-stimulated activation of NADPH-oxidase was altered by aging. Superoxide radical production of neutrophils of healthy ambulatory elderly (mean age 73 years) was increased compared to young adult controls. Expressed as nmol superoxide/min/mg protein, however, old cells were no different from young. Neutrophils of the elderly contained nearly 20% more protein/cell than young cells, yet neutrophil diameter and volume were not increased in the old cells. Binding affinity and maximum binding capacity of 3H-phorbol 12,13-dibutyrate were similar in young and old neutrophils. Maximum binding capacity was similar whether expressed on a per cell or per mg protein basis. Although others have suggested that initial plasma membrane events leading to superoxide radical production are diminished in aging cells, these studies show that intracellular phases of the mechanisms leading to superoxide radical production are maintained. Superoxide production rate per cell is increased in older persons, associated with a higher protein content per cell but not larger cell size.

Simultaneous measurement of neutrophil, lymphocyte, and monocyte glutathione by flow cytometry

A flow cytometric method for quantitation of glutathione (GSH) was applied to simultaneous analysis of the major leukocyte types in peripheral blood. Cellular thiols (predominantly GSH) were stained with monochlorobimane (MCIB), and thiol fluorescence was measured with a flow cytometer. The fluorescence of the thiols closely reflected the GSH content, as measured by a specific glutathione reductase assay. Fluorescence of individual cell types could be measured after delineating those cells by their light-scatter characteristics, utilizing dual-angle light scatter for discrimination. By this means, GSH contents of 12.5 +/- 2.0 nmol/10(7) neutrophils, 14.5 +/- 2.7 nmol/10(7) monocytes, and 5.0 +/- 1.0 nmol/10(7) lymphocytes were found. The results obtained for neutrophils with the flow cytometer were virtually identical with those obtained with chemical assay in purified samples of neutrophils, indicating the validity of the flow cytometric method.

Radioimmunoassay of oxfendazole in sheep fat

Oxfendazole (methyl 5-(phenylsulfinyl)-2-benzimidazole-carbamate) is a broad spectrum anthelmintic agent designed for use in food-producing animals. A simple radioimmunoassay (RIA) for determination of oxfendazole in plasma was modified for determining oxfendazole in sheep fat. Fat tissue was enzymatically hydrolyzed to an oily residue with collagenase-hyaluronidase, and oxfendazole was then extracted into an acidified aqueous phase. An aliquot of this phase was used directly for RIA. Bound radioactivity was separated from free by using polyethylene glycol-bovine gamma globulin because oils and other components in the aqueous aliquot preclude the use of charcoal for the separation. The lower limit of sensitivity of the assay is 0.003 ppm. Accuracy experiments carried out in the range 0.01-0.5 ppm gave a regression line of y (ng/g) = 0.91 x (ng/g) + 2.89, with r = 0.99. Fat tissue derived from sheep given an oral dose of 6.0 mg/kg was analyzed by this method and by a high pressure liquid chromatographic (HPLC) method. Values obtained by the 2 methods agreed well.

Reversed-phase high-pressure liquid chromatographic analysis of sulconazole in plasma

A sensitive and specific analytical method for the measurement of sulconazole in plasma is described. The compound was extracted from plasma at pH 10 with hexane-methylene chloride. Samples were subjected to high-pressure liquid chromatography (HPLC) using an acetonitrile-phosphate buffer mixture as the mobile phase. The components of interest were measured using a variable-wavelength detector at 229 nm. Sulconazole concentrations of greater than or equal to 0.5 microgram/ml can be measured with confidence using this method. Linear calibration curves were constructed over the concentration range of 0.5-5 microgram/ml for sulconazole from dog plasma. A dog was administered a single oral 1000-mg dose of tritiated sulconazole nitrate; total plasma radioactivity and sulconazole plasma levels determined by HPLC are reported.

Radioimmunoassay of plasma ethinylestradiol in the presence of circulating norethindrone

A reliable radioimmunoassay (RIA) for the measurement of ethinylestradiol (EE2) in plasma after the separation of norethindrone (NET) by column chromatography has been developed. The procedure involves diethyl ether extraction, followed by celite column partition chromatography to separate NET from EE2. An antiserum against ethinylestradiol-7-(3-thiopropionic acid)-bovine serum albumin conjugate was employed. Tritiated EE2 was used as the radioligand. The separation of bound from free 3H-EE2 was carried out with dextran-coated charcoal. This RIA procedure was used to measure plasma EE2 at specified time intervals in three women following oral administration of a tablet containing EE2 (0.12 mg) and NET (1.0 mg). The results show that EE2 is rapidly absorbed after oral administration. Peak concentrations of plasma EE2 were reached within 1.0 to 1.5 hours and then declined biphasically. The EE2 alpha phase half-life values in three subjects were 1.5, 2.8 and 3.8 hours. By comparison, the half-life values for the beta phase for the same three women were 6.2, 12.3 and 14.5 hours, respectively. Plasma samples were also analyzed for NET by RIA. The half-life values for the beta phase for EE2 and NET in the three subjects were similar.