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Biomedical subjects

J Henry

Publications and source records attributed to J Henry.

At least 37 records · Page 2Linked to original sources
PubMed2000

ILME: a waterborne pheromonal peptide released by the eggs of Sepia officinalis.

A novel tetrapeptide modulating the oviduct contractions was characterized from egg mass of Sepia officinalis. After two purification steps by rpHPLC, an apparent pure fraction containing the biological activity was submitted to MALDI-TOF analysis. The mass spectrum revealed 6 peaks of m/z 293, 505, 596, 613, 728, and 745. The tissue peptide mapping performed in LC-MS demonstrated the occurrence of the m/z 505 peptide in the follicles, the full-grown oocytes, and in the eggs. This peptide was also recovered in the seawater after the incubation of full grown oocytes or eggs, demonstrating a release in the genital tract and in the environment. Edman degradation gave the following sequence: Ileu-Leu-Met-Glu. The synthetic peptide applied to the whole genital tract triggered a cyclisation of the contractions at 10(-14) M. ILME appeared to be a chemical messenger released by the oocytes and the eggs, and was able to exert both paracrine and pheromonal activity.

Animals↗
PubMed2000

HPLC and electrospray ionization mass spectrometry as tools for the identification of APGWamide-related peptides in gastropod and bivalve mollusks: comparative activities on Mytilus muscles.

The APGWamide-related neuropeptides, predicted by the cDNA of the APGWamide precursor of Mytilus edulis, have been sought by means of HPLC and electrospray mass ionization. The three predicted peptides KPGWamide, RPGWamide and TPGWamide were detected in the three main muscles and surprisingly an ion at m/z 429 corresponding to the gastropod peptide APGWamide was also demonstrated. Similar investigations performed in Lymnaea stagnalis central nervous system (CNS) revealed the occurrence of mussel APGWamide-related peptides (APGWamide-RPs) demonstrating for the first time the presence and the expression of the two precursors in both gastropod and bivalve mollusks. The absence of homologous domain in the Mytilus precursor [P. Favrel, M. Mathieu, Molecular cloning of a cDNA encoding the precursor of Ala-Pro-Gly-Trp-amide related neuropeptides from the bivalve Mytilus edulis. Neurosci. Lett. 1996;205:210-214] and the Lymnaea precursor [A.B. Smit, C.R. Jiménez, R.W. Dirks, R.P. Croll, W.P.M. Geraerts, Characterization of cDNA clone encoding multiple copies of the neuropeptide APGWamide in the molluscs Lymnaea stagnalis. J. Neurosci. 1992;12:1709-1715] eliminates the hypothesis of an alternative splicing of a single gene and suggests the likelihood of two genes probably resulting from duplication of an ancestral gene before the divergence between gastropods and bivalves. The similar potency observed on contraction assay and the differential distribution of the various peptides suggest that they may exert distinct activities on multiple targets.

Animals↗
PubMed2000

Evidence of 5-hydroxytryptamine synthesis in the follicles of Sepia officinalis and direct involvement in the control of egg-laying.

At the beginning of egg-laying, in the cuttlefish Sepia officinalis, the oocytes accumulated in the proximal oviduct are released into the mantle cavity by the contractions of the oviduct before being encapsulated and fertilised. A bioassay based on the recording of the contractile activity of the distal oviduct was performed to characterise the molecule(s) inhibiting the oviducal motility and then responsible for the storage of the oocytes before mating. From 200 full-grown oocytes, a factor lowering the oviducal contractions was purified and isolated by means of HPLC. ESI-MS as well as electrochemical detection following HPLC fractionation allowed identification of the 5-hydroxytryptamine in the pure fraction. The inhibition of the oviducal contractions by 5-HT was dose dependent with a threshold near 10(-7) M. An immunoenzymatic assay showed that 5-HT appeared in the follicles at the beginning of vitellogenesis and reached a maximum level in the full-grown oocytes. In vitro experiments revealed that 5-HT is synthesised by the follicular cells and the full-grown oocytes, before being released to target proximal oviduct. Thus 5-HT could be one of the molecules involved in the accumulation of oocytes in the oviduct before mating. Mol. Reprod. Dev. 55:182-188, 2000.

Animals↗
PubMed2000

Child sexual abuse: a case study in community collaboration.

OBJECTIVE: This is an exploratory study that describes the process and outcomes of a Midwestern US community's approach to case management of child sexual abuse. METHOD: Data were abstracted from 323 criminal court files. Specific information gathered included child and suspect demographic data, law enforcement and CPS involvement, child disclosure patterns and caretaker responses, offender confession, offender plea, trial and child testimony information, and sentences received by offenders. Both case process and outcome variables were examined. RESULTS: In this community, criminal court records reflect a sex offense confession rate of 64% and a sex offense plea rate of 70%. Only 15 cases went to trial and in six the offender was convicted. CONCLUSION: Communities can achieve successful outcomes when criminal prosecution of sexual abuse is sought, but the child's testimony is not necessarily the centerpiece of a successful case. In this study, desired outcomes were a consequence of the collaborative efforts of law enforcement, CPS, and the prosecutor's office, which resulted in a high confession and plea rate.

Adolescent↗
PubMed2000

Application of neural networks and sensitivity analysis to improved prediction of trauma survival.

The performance of trauma departments is widely audited by applying predictive models that assess probability of survival, and examining the rate of unexpected survivals and deaths. Although the TRISS methodology, a logistic regression modelling technique, is still the de facto standard, it is known that neural network models perform better. A key issue when applying neural network models is the selection of input variables. This paper proposes a novel form of sensitivity analysis, which is simpler to apply than existing techniques, and can be used for both numeric and nominal input variables. The technique is applied to the audit survival problem, and used to analyse the TRISS variables. The conclusions discuss the implications for the design of further improved scoring schemes and predictive models.

Analysis of Variance↗
PubMed2000

Quantitative measurement of P- and E-selectin adhesion molecules in acute pancreatitis: correlation with distant organ injury.

OBJECTIVE: To determine whether expression of P- and E-selectin molecules is associated with the development of systemic organ manifestations in acute pancreatitis (AP). SUMMARY BACKGROUND DATA: Overproduction of inflammatory cytokines in AP induces expression of adhesion molecules, which may lead to increased leukocytic infiltration and tissue damage. Understanding the temporal expression of these molecules could afford better measures for therapeutic intervention. METHODS: Acute pancreatitis was induced in 30-day-old female C57/ bI/6J mice by feeding a choline-deficient/ethionine-supplemented diet (n = 95). Mice were divided into three groups. Group I (n = 35) was used to study the biochemical and histologic manifestations of AP and to evaluate the neutrophilic infiltration by myeloperoxidase activity and immunofluorescence. Groups II (n = 35) and III (n = 25) were used to evaluate expression of P- and E-selectin by the dual radiolabeled monoclonal antibody technique. RESULTS: Biochemical and histologic evidence of AP developed in all mice. The inflammatory cytokine tumor necrosis factor-alpha gradually increased in serum as early as 18 hours, reaching more than 800-fold background levels by 72 hours. Biphasic P-selectin expression in the lung was seen with peaks at 24 and 48 hours; E-selectin expression peaked at 48 hours. CD18-positive leukocytes and increased myeloperoxidase activity in the lung were demonstrated at 24 hours, correlating with the onset of selectin upregulation. Histologic scoring of lung tissue demonstrated mild damage at 24 hours, with progressive injury occurring from 48 to 72 hours. CONCLUSIONS: In AP, the production of inflammatory cytokines precedes up-regulation of P- and E-selectin, whose expression coincided with the increased infiltration of CD18-positive cells and neutrophil sequestration in lung tissue. Temporally, these events correlate with evidence of histologic pulmonary injury and underscore the role of adhesion molecules as mediators of pathophysiologic events. This mechanistic pathway may afford novel therapeutic interventions in clinical disease by using blocking agents to ameliorate the systemic manifestations of AP.

Acute Disease↗
PubMed2000

Intellectual and emotional functioning in college students following mild traumatic brain injury in childhood and adolescence.

OBJECTIVE: To investigate whether college students with a history of mild traumatic brain injury (TBI) in childhood or adolescence show residual deficits in intellectual functioning, approaches to studying, or emotional stability. DESIGN: Participants with a history of mild TBI and two control groups. SETTING: Volunteers were recruited from students taking an introductory psychology course. PARTICIPANTS: 79 students with a history of mild TBI, 75 students with a history of general anesthesia, and 93 students with no history of either TBI or general anesthesia. MAIN OUTCOME MEASURES: Participants carried out tests of verbal memory, nonverbal memory, verbal fluency, and nonverbal fluency; in addition, they completed a short form of the Approaches to Studying Inventory and the Symptom Checklist-90-Revised (SCL-90-R). RESULTS: In comparison with the two control groups, the students with a history of mild TBI produced similar scores on the cognitive tests and similar orientations to studying. However, they showed a significantly higher level of emotional distress on the SCL-90-R. CONCLUSION: College students with a history of mild TBI in childhood or adolescence are intellectually unimpaired and approach their studying in a similar manner to their uninjured classmates. Nevertheless, they report more severe distress in terms of their general personal and emotional functioning.

Adolescent↗
PubMed2000

Trypsin stimulates production of cytokines from peritoneal macrophages in vitro and in vivo.

Acute pancreatitis (AP) is characterized by release of proteolytic enzymes from the pancreas and a powerful inflammatory cytokine cascade that mediates the systemic manifestations and contributes to the mortality of the disease. The purpose of this study was to examine a potential link between pancreatic proteolytic enzymes, which are increased in AP, and cytokine production. To evaluate this, we incubated rat peritoneal macrophages (PMO) with increasing concentrations of trypsin and measured cytokine production. Supernatants from the cell cultures were assayed for TNF-alpha and IL-1beta, and the PMO were collected for the evaluation of cytokine mRNA by polymerase chain reaction (PCR). Further to evaluate the role of pancreatic proteases in triggering the cytokine cascade in AP, trypsin was injected into the peritoneal cavity of Sprague-Dawley rats, and the production of cytokines was measured in the peritoneal fluid. Controls included injection of inactivated trypsin. Incubation of PMO with trypsin in vitro resulted in a dose-dependent increase in TNF-alpha production with maximal response (2,660.5+/-748.8 pg/mL) at 10 microg/mL protease. Peak TNF-alpha and IL-1beta release was noted 16 h after stimulation of the PMO (2,759.5+/-698.0 pg/mL and 160,596+/-4,065 cpm, respectively). Trypsin-induced TNF-alpha production was not due to release of cell-associated cytokine, inasmuch as activation of PMO with this protease causing an increase in TNF-alpha mRNA by 30 minutes, reaching a 14-fold increase at 4 h. Trypsin-injected animals produced TNF-alpha-containing ascitic fluid in a dose-dependent manner with peak TNF-alpha at 2 h (371.3+/-180 pg/mL) versus control (53.8+/-11.2 pg/mL; p < 0.022). No TNF-alpha was found in ascites of rats injected with heat-inactivated trypsin. Histologic examination of trypsin-injected animals revealed evidence of pulmonary inflammation at 2 and 4 hours. We conclude that the proteolytic enzyme trypsin stimulates cytokine production from macrophages in vitro and in vivo. This model demonstrates for the first time that trypsin is a potential mediator of the cytokine response seen during AP.

Animals↗
PubMed2000

Non-gaussian velocity distributions in excited granular matter in the absence of clustering

The velocity distribution of spheres rolling on a slightly tilted rectangular two-dimensional surface is obtained by high speed imaging. The particles are excited by periodic forcing of one of the side walls. Our data suggests that strongly non-Gaussian velocity distributions can occur in dilute granular materials even in the absence of significant density correlations or clustering. When the surface on which the particles roll is tilted further to introduce stronger gravitation, the collision frequency with the driving wall increases and the velocity component distributions approach Gaussian distributions of different widths.

Journal Article↗
PubMed2000

An assessment of the role of liver biopsies in asymptomatic patients with chronic liver test abnormalities.

OBJECTIVE: The role of liver biopsy in the management of patients with nonspecific chronic liver enzyme abnormalities is not well established. The aim of this study is to determine whether liver histology changes the clinical impression formed before liver biopsy and the preliminary management plan. METHODS: Consenting asymptomatic adult patients with persistent (> or = 6 months) liver test abnormalities were enrolled. Patients with a strong suspicion for a specific liver disease were excluded. A presumptive diagnosis and a preliminary management plan were documented before a liver biopsy. After the liver biopsy, the patients were reassessed to determine the effect of the biopsy on the diagnosis and management plan. RESULTS: A total of 36 patients were enrolled: 15 men and 21 women, with a median age of 51 yr. The prebiopsy diagnoses were nonalcoholic steatohepatitis (24), autoimmune hepatitis (3), primary biliary cirrhosis (2), primary sclerosing cholangitis (2), and miscellaneous (5 patients). The liver biopsy changed the diagnosis in 14% of cases. Lifestyle recommendations were not significantly altered by the biopsy. The liver biopsy affected the frequency of liver test monitoring in 13 patients (36%). Treatment recommendations were affected in 12 cases, 10 of whom were offered investigational therapy. CONCLUSIONS: Although a liver biopsy may help to definitively establish the final diagnosis in patients, the results alter the presumptive prebiopsy diagnosis infrequently, and no proven therapy exists for the vast majority of these patients. Therefore, the risks and benefits of a liver biopsy should be carefully weighed, especially in settings in which investigational therapies are unavailable.

Biopsy↗
PubMed2000

The effects of HIV infection on endothelial function.

Endothelial dysfunction and/or injury is pivotal to the development of cardiovascular and inflammatory pathology. Endothelial dysfunction and/or injury has been described in Human Immunodeficiency Virus (HIV) infection. Elaboration of circulating markers of endothelial activation, such as soluble adhesion molecules and procoagulant proteins, occurs in HIV infection. Certain endothelial cells, such as those lining liver sinusoids, human umbilical vein endothelial cells, bone marrow stromal endothelial cells or brain microvascular endothelial cells, have been shown to be variably permissive for HIV infection. Entry of virus into endothelial cells may occur via CD4 antigen or galactosyl-ceramide receptors. Other mechanisms of entry including chemokine receptors have been proposed. Nevertheless, endothelial activation may also occur in HIV infection either by cytokines secreted in response to mononuclear or adventitial cell activation by virus or else by the effects of the secreted HIV-associated proteins, gp 120 (envelope glycoprotein) and Tat (transactivator of viral replication) on endothelium. Enhanced adhesiveness of endothelial cells, endothelial cell proliferation and apoptosis as well as activation of cytokine secretion have all been demonstrated. Synergy between select inflammatory cytokines and viral proteins in inducing endothelial injury has been shown. In HIV infection, dysfunctional or injured endothelial cells potentiate tissue injury, inflammation and remodeling, and accelerate the development of cardiovascular disease.

Animals↗
PubMed1999

Modulation of gastrin processing by vesicular monoamine transporter type 1 (VMAT1) in rat gastrin cells.

1. Gastrointestinal endocrine cells produce biogenic amines which are transported into secretory vesicles by one of two proton-amine exchangers, vesicular monoamine transporters type 1 and 2 (VMAT1 and 2). We report here the presence of VMAT1 in rat gastrin (G) cells and the relevance of VMAT1 function for the modulation of progastrin processing by biogenic and dietary amines. 2. In immunocytochemical studies VMAT1, but not VMAT2, was localized to subpopulations of G cells and enterochromaffin (EC) cells; neither was found in antral D cells. The expression of VMAT1 in antral mucosa was confirmed by Northern blot analysis, which revealed an mRNA band of approximately 3.2 kb, and by Western blot analysis, which revealed a major protein of 55 kDa. 3. In pulse-chase labelling experiments, the conversion of the amidated gastrin G34 to G17 was inhibited by biogenic amine precursors (L-DOPA and 5-hydroxytryptophan). This inhibition was stereospecific and sensitive to reserpine (50 nM), which blocks VMAT1 and VMAT2, but resistant to tetrabenazine, which is a selective inhibitor of VMAT2. 4. Dietary amines such as tyramine and tryptamine also inhibited G34 cleavage. This effect was associated with a loss of the electron-dense core of G cell secretory vesicles. It was not stereospecific or reserpine sensitive, but was correlated with hydrophobicity. 5. Thus rat antral G cells can express VMAT1; transport of biogenic amines into secretory vesicles by VMAT1 is associated with inhibition of G34 cleavage, perhaps by raising intravesicular pH. Dietary amines also modulate cleavage of progastrin-derived peptides, but do so by a VMAT1-independent mechanism; they may act as weak bases that passively permeate secretory vesicle membranes and raise intravesicular pH.

Amino Acids↗
PubMed1999

A comparison of fatal with non-fatal knife injuries in Edinburgh.

Assault using a knife is a common problem in the United Kingdom. Between February 1992 and December 1996, 120 individuals died or received hospital treatment in Edinburgh after being assaulted with a knife. Twenty individuals (17%) died as a result of their injuries. Comparison of the survivors with non-survivors revealed both groups to have similar age and sex distributions, but those who died had significantly more severe injuries when scored according to the Abbreviated Injury Scale. Eight individuals died of unsurvivable chest injuries at the scene of the attack and of the remainder, only five reached hospital with signs of life. Analysis of hospital treatment using TRISS methodology revealed there to be two unexpected survivors and no unexpected deaths. The risk of death appears to depend mostly upon injuries sustained and also to a lesser extent upon other factors such as alcohol consumption and the presence of a bystander capable and willing to request emergency medical assistance. There does not appear to be much potential to save lives by improving hospital treatment for those assaulted with a knife in Edinburgh. Instead, greater focus needs to be placed upon rapid transfer to hospital and upon restricting the possession and use of knives.

Adolescent↗
PubMed1999

Unsedated small-caliber esophagogastroduodenoscopy (EGD) versus conventional EGD: a comparative study.

BACKGROUND & AIMS: Significant portions of the cost and complications of esophagogastroduodenoscopy (EGD) are related to sedation. This study aimed to assess the feasibility, acceptability, and accuracy of unsedated small-caliber transoral EGD (sc-EGD). METHODS: A 4-phase study was performed in healthy volunteers and patients. Phases 1 and 2 involved assessment of the technical feasibility of sedated sc-EGD and the tolerability of unsedated sc-EGD, respectively, in volunteers. Subsequently, the technical feasibility, tolerability, and diagnostic accuracy of sedated and unsedated sc-EGD were determined by having each patient undergo sc-EGD (Pentax EG-1840) with (phase 3) and without (phase 4) sedation, followed by sedated conventional EGD (c-EGD) (Olympus GIF-100 or GIF-Q140) by a staff endoscopist blinded to the findings of the sc-EGD. The t test for paired samples was used for statistical analysis. A P value of <0.05 was considered significant. RESULTS: Sedated and unsedated sc-EGD were technically feasible and tolerable in all volunteers. In patients, compared with sedated c-EGD, sedated and unsedated sc-EGD were 96% and 97% accurate, respectively. The overall acceptability of unsedated sc-EGD was only slightly worse than that of sedated c-EGD (median, 2 vs. 1 on a scale of 1-10). After unsedated sc-EGD, 98% of patients expressed willingness to undergo the procedure again. No complications were observed during any phase of the study. CONCLUSIONS: Unsedated sc-EGD is technically feasible, tolerable, and accurate. It can potentially decrease the costs and complications of sedated conventional EGD.

Adult↗
PubMed1999

The association between seniority of Accident and Emergency doctor and outcome following trauma.

The actual survival of patients treated following trauma in four Scottish Teaching hospitals during five years was compared with predicted survival according to TRISS analysis. The data were analysed according to the seniority of the Accident and Emergency (A&E) doctor treating each patient. The group of patients treated by a consultant had a significantly better outcome (p < 0.05) than the group of patients treated by junior doctors. Analysis of outcome according to the grade of junior A&E doctor suggested a step-wise improvement in outcome with seniority, thus supporting the concept that an improved outcome is associated with experience and seniority. These results support calls for A&E consultants to be increasingly involved in the management of patients with major trauma. Such increased involvement would require an increase in the number of A&E consultants.

Chi-Square Distribution↗