Unexpected results found in larvae samples from two postmortem forensic cases

Forensic Toxicology - In forensics, entomological specimens can be used as additional/alternative matrices to detect xenobiotics when human specimens are limited in their application. Despite some...     

Diesel exhaust exposure enhances the expression of IL-13 in the bronchial epithelium of healthy subjects

Epidemiological studies have demonstrated adverse health effects of environmental pollution. Diesel exhaust (DE) is an important contributor to ambient particulate matter pollution. DE exposure has been shown to induce a pronounced inflammatory response in the airways, with an enhanced epithelial expression of IL-8, and Gro-alpha in healthy subjects. The present investigation was aimed to further characterise the epithelial response to DE in vivo, with particular reference to possible TH2 response, in non-atopic healthy subjects. To determine this response, 15 healthy, non-atopic non-smoking subjects with normal lung function were exposed to DE (PM10 300 microg/m3) and filtered air during 1 h on two separate randomised occasions. Bronchoscopy sampling of bronchial mucosal biopsies was performed 6 h after exposure. Immunohistochemical staining were performed using mAb for IL-10, IL-13 and IL-18 expression. DE exposure induced a significant increase in the expression of IL-13 in the bronchial epithelium cells, 2.1 (1.35-4.88) Md (Q1-Q3) vs. air 0.94 (0.53-1.23); P = 0.009. No significant changes were seen in IL-10 and IL-18 expression. This finding suggests an TH2-inflammatory response in the airways of non-atopic healthy individuals.     

Lower anticoagulation for mechanical heart valves: experience with the ATS bileaflet valve

Background: The design of the bileaflet ATS (ATS Medical Inc., Minneapolis, USA) mechanical valve incorporates an open pivot at the hinge mechanism. Total washout of the blood at the pivot area was observed using 3-D computational fluid dynamics modelling. This phenomenon could make the valve less vulnerable to clot formation in patients without major thromboembolic risk factors.

Methods: From January 1993 to June 1999, 286 consecutive patients had the ATS valve inserted in the aortic position. Patients were divided into two groups. Group 1 comprised all patients in regular sinus rhythm with good left ventricular function (144 patients). Group 2 included patients in non-sinus rhythm and/or with large hypocontractile left ventricles (142 patients). The anticoagulation regime in group 1 was used to obtain an international normalised ratio (INR) between 1.5 and 2.5. This contrasts with our regular aim to maintain the INR strictly between 2.5 and 3.5 for all mechanical valves, as achieved in group 2.

Results: The follow-up period (99% completeness) ranged from 18 to 84 months. Survival (Kaplan-Meier) was 97 and 98% and 92 and 81% at 1 and 5 years in group 1 and group 2, respectively (P = 0.12). Log rank analysis failed to detect a statistical difference in thromboembolism or bleeding between both groups (P > 0.05). However, trends were in favour of group 1. Univariate analysis selected poor ventricular function and an ‘erratic’ INR value (P = 0.002) as risk factors for death. The sole independent risk factor for bleeding was the use of aspirin (P = 0.025).

Conclusions: The excellent group 1 data and outcome encouraged us to continue our low intensive anticoagulation regime and perhaps should be regarded as a new concept for treatment of selected mechanical valve patients.     

An assessment of the management of acute bleeding varices: a multicenter prospective member-based study

OBJECTIVE: Bleeding from esophagogastric varices is a major complication of portal hypertension. Despite recent practice guidelines for the management of bleeding esophageal or gastric varices, the widespread application of these measures by gastroenterologists has not been evaluated. The purpose of this study was to continue the concept of membership-based research within diverse practice settings by expanding the American College of Gastroenterology (ACG) GI Bleeding Registry to assess the management and outcome of acute variceal bleeding. METHODS: All ACG members (domestic and foreign) were invited to participate during the 1997 Annual Fall meeting and by mail. Data were collected over 12 months. Information obtained included physician training, practice demographics, patient demographics, disease etiology and severity, clinical presentation, medications, transfusion needs, therapy, complications, and rebleeding within 2 wk. RESULTS: A total of 93 physicians/centers (79.6% domestic, 26.9% university and affiliated, 3.2% Veterans Affairs) participated. Complete demographic data were available for 725 of the 741 patients enrolled with index bleeding. The median age of these 725 patients was 52 yr and 73.3% were male. The most common single etiology for portal hypertension was cirrhosis (94.3%). The most common causes of cirrhosis were alcohol (56.7%), hepatitis C virus (30.3%), and hepatitis B virus (10.0%). Hemodynamic instability was noted in 60.7% of the patients (22.3% tachycardic, 9.7% orthostatic, 28.7% hypotensive). Index interventions included banding (40.8%; median five bands), sclerotherapy (36.3%), combination banding/sclerotherapy (6.2%), octreotide (52.6%; median 3 days), balloon tamponade (5.5%), transjugular intrahepatic portosystemic shunt (TIPS) (6.6%), liver transplantation (1.1%), surgical shunt (0.7%), and embolization (0.1%). Transfusion of packed red blood cells, fresh frozen plasma, and platelets was given in 83.4%, 44.7%, and 24.6% of the patients with index bleeding, respectively. Median transfusion was four units of packed red blood cells, three units of fresh frozen plasma, and 1.5 units of platelets. Rebleeding occurred in 92 of the 741 patients (12.6%) at a median of 7 days (mean 11 days) and was treated by banding (18.5%; median six bands), sclerotherapy (30.4%), octreotide (63%; median 2 days), balloon tamponade (17.4%), TIPS (15.2%), and surgical shunt (3.3%). Complications from the index bleeding and rebleeding within 2 wk included ulceration (2.6%, 2.2%), aspiration (2.4%, 3.3%), medication side effects (0.8%, 0%), dysphagia (2.3%, 0%), odynophagia (2.2%,0%), encephalopathy (13%,17.4%), and hepatorenal syndrome (2.4%, 2.2%), respectively. After the index bleeding, 46.2% of patients were treated with beta-blockers and 8.2% with nitrates. The majority of patients with index bleeding had Child's B cirrhosis (61.5%). Patients presenting with recurrent bleeding had mostly Child's B (46.7%) or Child's C cirrhosis (44.6%). The overall short-term mortality after index bleeding was 12.9%. CONCLUSIONS: Acute variceal hemorrhage occurs more often in patients with Child's B and C cirrhosis. Endoscopic banding is the most common single endoscopic intervention. Adjunctive pharmacotherapy is prevalent acutely and after stabilization. Both morbidity and mortality may be lower than reported in previous studies.     

Overexpression of murine TSLP impairs lymphopoiesis and myelopoiesis

The role of thymic stromal cell-derived lymphopoietin (TSLP) in regulating hematopoiesis is poorly characterized, so we investigated its regulatory effects in vivo using TSLP transgenic mice. Overexpression of TSLP disrupted hematopoietic homeostasis by causing imbalances in lymphopoiesis and myelopoiesis. Mice harboring a TSLP transgene had 5- to 700-fold fewer B and T precursors and no detectable pre-B lymphocyte colonyforming activity in the marrow or spleen. Conversely, TSLP transgenic mice possessed 15 to 20 times more splenic myeloid precursors than their littermates, and progenitor activity of the granulocyteerythrocyte-macrophage-megakaryocyte colony-forming units was significantly elevated. The arrest in lymphopoiesis and the expansion of myeloid progenitor cells in TSLP transgenic mice suggest that TSLP has negative and positive regulatory effects on lymphoid and myeloid development, respectively.     

Videocapsule endoscopy versus barium contrast studies for the diagnosis of Crohn's disease recurrence involving the small intestine

OBJECTIVES: Historically, suspected Crohn's disease (CD) has been evaluated with small bowel follow-through (SBFT) or enteroclysis (equally accurate). This study was undertaken to determine the accuracy of videocapsule endoscopy (VCE) in the diagnosis of CD relative to SBFT and clinical/laboratory indices of CD activity. Previous investigations have used VCE for the diagnosis of suspected CD in patients presenting with a variety of gastrointestinal symptoms. This is the first study to evaluate the occurrence of active disease in patients with known CD. METHODS: Thirty subjects (22 female, 8 male, aged 36.9 +/- 14.2 yr); all with prior CD diagnosis made on the basis of standard criteria (5.5 +/- 6.5 yr prior to study), in whom recurrent CD was suspected based on abdominal pain, diarrhea, anemia, and/or arthralgias. Subjects were studied in a prospective, blinded evaluation of VCE versus SBFT. SBFT was performed first; those with stricture and proximal bowel dilation were excluded from further study. For SBFT, studies were graded as grade 0 (normal), grade 1 (minimal nodularity, ulcerations, normal luminal diameter, < 5 cm involved), grade 2 (more extensive ulcers, minimal luminal narrowing, 5-10 cm involved), or grade 3 (fistula, skip areas, extensive ulceration, >10 cm involved). VCE was performed within 1 wk of SBFT. Serum was obtained for ESR (erythrocyte sedimentation rate) and CRP (C-reactive protein), stool was obtained for alpha-1 antitrypsin, and the Harvey Bradshaw index of CD severity was calculated. VCE (digitalized video) was graded as grade 0 (normal), grade 1 (erythema, isolated villi loss), grade 2 (erosion, no ulcer), or grade 3 (ulcers, spontaneous bleeding, and/or stricture). RESULTS: Twelve patients were excluded for small bowel obstruction. VCE and SBFT scores highly correlated (r = 0.65; p= 0.001). Active CD was visualized in 21 of 30 patients with videocapsule endoscopy and in 20 of 30 patients with SBFT. Complete agreement occurred in 13 of 30 studies; 13 of 17 studies differed by one grade. SBFT found mucosal disease in 20 of 30 patients and VCE found mucosal disease in 21 of 30 patients. VCE found mucosal disease in 6 patients (5 in grade 1, 1 in grade 3) with normal SBFT. SBFT showed CD in 5 patients (all grade 1) with normal VCE. Neither VCE nor SBFT scores correlated with biological or clinical indices. Patient satisfaction was superior for VCE. CONCLUSIONS: VCE and SBFT are complementary for the diagnosis of CD. SBFT may be required to detect strictures as the videocapsule may not pass. However, some strictures may also be missed with SBFT. VCE is less invasive, less time-consuming for the patient than SBFT, and avoids radiation exposure, although reading time is greater for the gastroenterologist than the radiologist. Given that patients with clinically suspected CD recurrence may not have active disease, unnecessary and potentially harmful empiric therapy is not warranted without imaging.     

The VEGF receptor flt-1 (VEGFR-1) is a positive modulator of vascular sprout formation and branching morphogenesis

Sprouting angiogenesis is critical to blood vessel formation, but the cellular and molecular controls of this process are poorly understood. We used time-lapse imaging of green fluorescent protein (GFP)-expressing vessels derived from stem cells to analyze dynamic aspects of vascular sprout formation and to determine how the vascular endothelial growth factor (VEGF) receptor flt-1 affects sprouting. Surprisingly, loss of flt-1 led to decreased sprout formation and migration, which resulted in reduced vascular branching. This phenotype was also seen in vivo, as flt-1(-/-) embryos had defective sprouting from the dorsal aorta. We previously showed that loss of flt-1 increases the rate of endothelial cell division. However, the timing of division versus morphogenetic effects suggested that these phenotypes were not causally linked, and in fact mitoses were prevalent in the sprout field of both wild-type and flt-1(-/-) mutant vessels. Rather, rescue of the branching defect by a soluble flt-1 (sflt-1) transgene supports a model whereby flt-1 normally positively regulates sprout formation by production of sflt-1, a soluble form of the receptor that antagonizes VEGF signaling. Thus precise levels of bioactive VEGF-A and perhaps spatial localization of the VEGF signal are likely modulated by flt-1 to ensure proper sprout formation during blood vessel formation.     

Diminished posttetanic potentiation in failing human myocardium

In heart failure a decreased function of SERCA2 has been demonstrated. The present study aimed at investigating the relation between sarcoplasmic reticulum-Ca²⁺-load (SR-Ca²⁺-load) and the activity of the SERCA2. SR-Ca²⁺ load was evaluated by measuring posttetanic potentiation (PTP) in human nonfailing (NF, n=10) and endstage failing myocardium (DCM, n=11). In addition, the effect of cyclopiazonic acid (CPA), a specific inhibitor of SERCA2, on PTP was studied in both NF and DCM. In crude membrane preparations from the same hearts the maximal SERCA2 activity was determined and correlated with the PTP. In failing myocardium the PTP was significantly reduced compared to nonfailing myocardium (13.7±0.75 mN/mm² vs. 17.1±1.55 mN/mm², p<0.05, ±SEM). When PTP was studied in the presence of increased extracellular Ca²⁺-concentrations, the difference between NF and DCM was further pronounced. CPA decreased PTP in both nonfailing and failing human tissue. The maximal SERCA2 activity was significantly reduced in failing myocardium (NF 267±18.5 nmol ATP/mg protein · min⁻¹ vs. DCM 191±13.4 nmol ATP/mg protein · min⁻¹, p<0.05, ± SEM). Correlation of the PTP and maximal SERCA2 activity revealed a close correlation between both parameters in NF and DCM. In summary, the presented results suggest that reduced SERCA2 activity in DCM influences posttetanic force potentiation probably through a reduced SR-Ca²⁺-load. Received: 30 July 1999 Returned for 1. revision: 9 September 1999 1. Revision received: 24 November 1999 Returned for 2. revision: 26 January 2000 2. Revision received: 26 April 2000 Accepted: 9 May 2000     

Serum levels of sex hormone-binding globulin (SHBG) are not associated with lower levels of non-SHBG-bound testosterone in male newborns and healthy adult men

OBJECTIVE: It is generally accepted that SHBG decreases the bioavailability and activity of testosterone (T). In in vitro experiments increased levels of SHBG will be associated with decreased levels of non-SHBG bound testosterone (non-SHBG-T). However, in vivo SHBG can alter both production and clearance rates and thus plasma levels of T. DESIGN AND PATIENTS: In order to study the effect of SHBG on the levels of non-SHBG-T in vivo in the presence of an active hypothalamo-pituitary-gonadal (HPG) axis we conducted a cross sectional study in 400 healthy adult men with an age range of 40-80 years and in 106 newborn boys. MEASUREMENTS: In both groups, regression coefficients (beta) and partial correlation coefficients (r) were calculated for the relationship between SHBG and T or non-SHBG-T. Adult men were divided into age groups per decade (40-50 years, 51-60 years, 61-70 years and 71-80 years) to study possible differences in the impact of SHBG on the level of non-SHBG-T throughout ageing. RESULTS: Higher levels of SHBG were associated with higher levels of total testosterone in neonates (beta = 0.02 +/- 0.004, r = 0.44, P < 0.001) but not with non-SHBG-T (beta = -0.001 +/- 0.001, r = 0.05, P = 0.52). In adult men there was a significant age related increase in levels of SHBG and an age-related decrease of both total and non-SHBG-T. Higher SHBG was strongly associated with higher total testosterone in all age groups (beta = 0.26, 0.26, 0.26 and 0.23 for 40-50 years, 51-60 years, 61-70 years and 71-80 years, respectively, P < 0.001 for all age groups). Higher SHBG was not or only slightly associated with higher non-SHBG-T beta = 0.02 (P = 0.32), beta = 0.04 (P = 0.03), beta = 0.04 (P = 0.02) and beta = 0.02 (P = 0.16) for 40-50 years, 51-60 years, 61-70 years and 71-80 years, respectively. CONCLUSIONS: In contrast to general belief, SHBG levels barely influence levels of non-SHBG-bound testosterone both in male newborns and healthy adult men: the influence, if any, is positive. Consequently the age related increase of SHBG does not account for the age related decline in non-SHBG-T in healthy adult men.