Thumb basal joint arthritis: New classification, diagnostic and therapeutic algorithm.

The assessment of thumb basal joint arthritis requires a radiographic evaluation and a classification of the lesions to guide the treatment choice. Arthritis of the thumb basal joint is not limited to trapeziometacarpal arthritis. The radiographic assessment must consider the scaphotrapeziotrapezoid joint, the entire carpus and the rest of the thumb column, in particular the metacarpophalangeal joint. There is currently no classification that captures all these items. This article reviews the existing classifications, proposes a new classification system that takes into account the entire thumb column and sets out the therapeutic options.

Resistance profile and treatment outcomes in HIV-infected children at virological failure in Benin, West Africa.

Background: In Africa a high percentage of HIV-infected children continue to experience HIV treatment failure despite enormous progress. In Benin (West Africa), there are currently no data on HIV drug resistance at failure in paediatric populations. Objectives: To assess the frequency and patterns of HIV drug resistance among children with virological ART failures. Methods: Dried blood spots from 62 HIV-infected children with virological failure were collected at the paediatric clinic of the National Hospital Center in Cotonou for genotyping and plasma drug concentration determination. Results: Characteristics of the population show a median age of 10 years (IQR 6-13) and a median duration on ART of 5 years (IQR 3-7). Viruses from 53 children were successfully amplified. Of these, 76% of patients were on an NNRTI-based regimen and 24% on a boosted PI-based regimen. NRTI, NNRTI and dual-class resistance was present in 71%, 84% and 65% of cases, respectively. Only 4% of the children had major resistance mutations to PIs and none had major resistance mutations to integrase inhibitors. Among the participants, 25% had undetectable antiretroviral concentrations. Conclusions: Our results showed that the development of drug resistance could be one of the main consequences of high and continuous viral replication in HIV-infected children in Benin. Thus, inadequate attention to monitoring lifelong ART in children may prevent achievement of the goal of the United Nations Program on HIV and AIDS (UNAIDS) of 90% viral suppression among patients receiving ART.

[Profile of HIV-infected children at the National University Hospital of Cotonou (CNHU)]. / Profil des enfants infectes par le vih suivis au centre National Hospitalier et Universitaire (CNHU) de Cotonou.

OBJECTIVE: To describe the profile of HIV-infected children. METHODS: This was a cross-sectional, descriptive and analytic study involving 317 infected children, monitored from January 1st, 2002 to July 31st, 2010 at CNHU of Cotonou. RESULTS: The average age was 89.1 months with a sex ratio of 0.91. Orphans of at least one parent represented 31.3% of cases. Vertical transmission was predominant (86.1%). Only 9.5% of patients benefited from PMTCT. They were all infected with HIV 1. According to the WHO classification, 52% were at stage 3 or 4 and 56% had advanced to severe immunodeficiency. 61% had suffered from opportunistic infections, and 53% had benefited from antiretroviral therapy. Following the study, 54% of participants had continued follow-up visits, 23% lost contact with the CNHU, 18% died and 5% were referred to another site. Factors associated with outcome were antiretroviral therapy (p < 0.0001), clinical (p < 0.0001) and immunological stage (p = 0.0042) on admission. CONCLUSION: Our findings suggest strengthening the PMTCT program, screening and early management of an HIV infection.

OBJECTIF: Décrire le profil des enfants infectés par le VIH. PATIENTS ET MÉTHODES: Etude transversale, descriptive et analytique portant sur 317 enfants infectés, suivis de Janvier 2002 à Juillet 2010. RÉSULTATS: L'âge moyen des enfants était de 89,1 mois ; le sex ratio de 0,91. Ils étaient orphelins d'au moins un parent dans 31,3% des cas. La transmission était essentiellement verticale (86,1%). Seulement 9,5% avaient bénéficié d'une prophylaxie antirétrovirale pour la PTME. Ils étaient tous infectés par le VIH 1. Selon la classification de l'OMS, 52% étaient à un stade clinique 3 ou 4 et 56% avaient un déficit immunitaire important ou sévère. 61% avaient souffert d'infections opportunistes, et 53% avaient bénéficié du traitement antirétroviral. Quant à leur devenir, 54% avaient continué le suivi, 23% étaient perdus de vue, 18% étaient décédés et 5% transférés sur un autre site de prise en charge. Les facteurs associés au devenir étaient le traitement antirétroviral (p < 0,0001), les stades clinique (p < 0,0001) et immunologique (p = 0,0042) à l'admission. CONCLUSION: Ce profil suggère le renforcement du programme de la PTME, un dépistage et une prise en charge précoces.

Functionalization of titanium surface with chitosan via silanation: 3D CLSM imaging of cell biocompatibility behaviour.

INTRODUCTION: Biocompatibility ranks as one of the most important properties of dental materials. One of the criteria for biocompatibility is the absence of material toxicity to cells, according to the ISO 7405 and 10993 recommendations. Among numerous available methods for toxicity assessment; 3-dimensional Confocal Laser Scanning Microscopy (3D CLSM) imaging was chosen because it provides an accurate and sensitive index of living cell behavior in contact with chitosan coated tested implants. OBJECTIVES: The purpose of this study was to investigate the in vitro biocompatibility of functionalized titanium with chitosan via a silanation using sensitive and innovative 3D CLSM imaging as an investigation method for cytotoxicity assessment. METHODS: The biocompatibility of four samples (controls cells, TA6V, TA6V-TESBA and TA6V-TESBAChitosan) was compared in vitro after 24h of exposure. Confocal imaging was performed on cultured human gingival fibroblast (HGF1) like cells using Live/Dead® staining. Image series were obtained with a FV10i confocal biological inverted system and analyzed with FV10-ASW 3.1 Software (Olympus France). RESULTS: Image analysis showed no cytotoxicity in the presence of the three tested substrates after 24 h of contact. A slight decrease of cell viability was found in contact with TA6V-TESBA with and without chitosan compared to negative control cells. CONCLUSION: Our findings highlighted the use of 3D CLSM confocal imaging as a sensitive method to evaluate qualitatively and quantitatively the biocompatibility behavior of functionalized titanium with chitosan via a silanation. The biocompatibility of the new functionalized coating to HGF1 cells is as good as the reference in biomedical device implantation TA6V.

[Drug eruptions in children in Cotonou, Benin]. / Toxidermies Chez Les Enfants A Cotonou, Benin.

INTRODUCTION: The aim of this study was to investigate the epidemiological aspects of drug eruptions in children in hospital area in Cotonou. PATIENTS AND METHOD: A retrospective study was carried out in the Department of Dermatology of Cotonou (Benin) from 1998 to 2009. All cases of drug eruption occurred, during the study period, in children under 16 years old were selected for the study. The diagnosis of the drug eruption was based on clinical findings. The Identification of culprit drugs was based on the criteria as defined by the French Group of Pharmaco-vigilance. RESULTS: From 1998 to 2009, 232 cases of drug eruption were diagnosed in the Department of Dermatology. Of this, 35 cases occurred in children under 16 years old. The patient mean age was 6.6 years with a sex ratio of 0.94. 4 patients were HIV positive. The culprit drug was identified in 21 patients (60%): sulfonamides 52.38% (11/21 cases), penicillin 9.52% (2 cases), vaccine 9.52% (2 cases), acetaminophen 9.52% (2 cases), acetyl salicylic acid 4.76% (n = 1), quinine 4.76% (n = 1), phenobarbital 4.76% (n = 1) and ceftriaxone 4.76% (n = 1). The main clinical patterns were: fixed drug eruption 45.71% (16/35), maculopapular rash 17.14% (n = 6), Stevens-Johnson syndrome 17.14% (n=6), and urticaria 8.57% (n = 3), 1 case of toxic epidermal necrolysis was seen and one patient died. CONCLUSION: Skin reactions caused by drug intake are a rare disorder among children and fixed drug eruption is the main clinical presentation of the disease in Cotonou (Benin).

[Usefulness of neonatal exams at Cotonou University Hospital, Benin]. / Utilite De L'Examen Systematique Du Nouveau-Ne Au CNHU De Cotonou Au Benin.

AIM: To determine the rate of systematic examination completion, the characteristics of the newborns and the diseases that they bore. METHOD: It was a cross-sectional and descriptive study conducted on newborns that were received for systematic examination from January 1rst 2008 through December 31rst 2009. Consultations were performed by pediatricians. The data that were collected, included in details the rate of implementation of the systematic examination, the neonates demographic characteristics, detected diseases and risk factors. RESULTS: In 2 years, 1325 infants were seen for systematic examination in the neonatal unit of National Teaching Hospital of Cotonou. The global completion rate was estimated to 52%. Newborns were categorized as healthy, at risk of illness or ill in respectively 35.54%, 11% and 53% of cases. The diseases that were found encompassed jaundice (78%), neonatal infections (15%), antenatal growth retardation (12%), prematurity (10%) and birth defects (4.50%). Out of 707 sick newborns, 139 had been hospitalized with a fatal outcome in only one. CONCLUSION: The newborns systematic examination is useful. We do think that it should be generalized if we hope to reduce the neonatal mortality rate in Sub-.Saharan African countries.

Paediatric tuberculosis at the national teaching hospital CNHU-HKM of Cotonou, Benin: a retrospective study.

UNLABELLED: BACKGROIUND: Tuberculosis (TB) is a public health problem. Knowing its patterns could help address it more efficiently. OBJECTIVE: To determine the hospital incidence, presentation, management, and outcome of TB in our setting. METHODS: We conducted a chart review of children with TB during a five-year period at the University Hospital CNHU-HKM, Cotonou, Benin. RESULTS: Hospital prevalence of TB among hospitalised children was 0.2%. The mean age was six years, with a male:female ratio of 1.4:1. The common clinical features were: cough (78.1%), long standing fever (81.2%), growth retardation (65.6%), pulmonary consolidation (53.1%) and hepatosplenomegaly (34.4%). The skin tuberculin test was positive in only 40.6% of cases. Co-infection with HIV was present in 51.8% of cases. Mycobacterium tuberculosis could be identified in only 21.8% of cases. Twenty-six (81.2%) pulmonary tuberculosis (PTB) cases were diagnosed, eight (25%) of which were associated with extra pulmonary TB. Six (18.7%) presumed isolated extra PTB were also diagnosed. Eight-month treatment regimen was used in most patients, with mortality rate of 9.3%. CONCLUSION: Although TB hospital prevalence seems low in our setting, management needs to be improved according to guidelines.

[About a case of congenital hypothyroidism]. / A propos d'un cas d'hypothyroïdie congénitale.

A boy presented at birth dyspnea, jaundice, meteorism and hypospadias; biochemical testing revealed hyponatremia. He benefited on day 4 of neonatal screening for hypothyroidism and congenital adrenal hyperplasia (CAH) and assays showed high concentrations of 17-OHP and TSH. Because of clinical features and hyponatremia, the diagnosis of CAH was plausible. A serum control (17-OHP and TSH) carried out on day 8 showed a normal concentration of 17-OHP and a persistently elevated concentration of TSH confirmed by a second assay a few days later. A 131I scan of neck revealed an ectopic lingual thyroid. The considerable progression of false positive screening tests for CAH is mainly due to the increasing number of premature babies. We show by a retrospective analysis (7 yrs), that children with hypothyroidism also present frequently higher concentrations of 17-OHP than normal children. However, whatever the aetiology (apart from CAH), the concentrations of 17-OHP rapidly normalise.

[Recurring pulmonary embolism despite the presence of a vena cava filter: a case report from the CNHU Cotonou-Benin]. / Embolie pulmonaire récidivante malgré la présence d'un filtre cave définitif: á propos d'un cas observé au CNHU de Cotonou-Bénin.

A 50-year-old man presents several clinical signs of pulmonary embolism, but this diagnosis was excluded due to the lack of venous thrombosis of the lower limbs and because the presence of a vena cava filter. The same signs reoccurred a few months later, leading to the diagnosis of venous thrombosis of the lower limbs with severe successive pulmonary embolism. This clinical case illustrates the potentially incomplete efficacy of vena cava filters for the prevention of pulmonary embolism.

[Prevention of HIV mother to child transmission in Cotonou: child follow-up]. / Suivi de l'enfant de mère infectée par le VIH dans le cadre de la prévention de la transmission mère-enfant à Cotonou (Bénin).

UNLABELLED: The aim of this survey was to analyse the constraints of implementing on a larger scale the protocol of prevention of HIV/AIDS from mother to child by Nevirapine intake. This survey takes stock of the components of the children medical care follow-up. PATIENTS AND METHODOLOGY: Here is a straight line survey on 231 newborns from 222 screened mothers during pregnancy in 36 Health Centres in Cotonou and suburbia. Nevirapine has been administered in a single dose of 200 mg to mothers during labour and a dosage of 7 mg to the infant at birth. These infants have been steadily followed-up from 13 June 2000 to 30 April 2002. Exclusively feeding either on artificial milk or breastfeeding and a premature weaning at four months of age have been recommended. PCR screening has been conducted at one and six months of age or one month after the effective weaning. Cotrimoxazole has been systematically administered at six weeks. RESULTS: HIV/AIDS sero prevalence was globally evaluated at 4% in the screened pregnant women. One hundred and ninety seven mothers and children have effectively benefited from nevirapine intakes and this protocol has been adequately observed in 51% cases. The medical check-up rate was 18.5%. The average age of children under medical care was 10.8 months at the end of the study. The mother to child transmission rate was globally estimated at 20.4% and 7% in an optimal situation (the protocol was observed and the rate of CD4 above 500). In case of breastfeeding exclusively followed by a premature weaning in most cases, the average age of effective weaning was 8.3 months. Twenty-three children died during medical care follow-up basically from dehydration brought about by diarrhea and vomiting during weaning period. CONCLUSION: The survey confirms the potency of nevirapine in preventing HIV transmission from mother to child in non immunosuppressed women and lays emphasis on real problems for which appropriate solutions should be found before the implementation on a larger scale of this protocol.

Effect of haemodilution with diaspirin cross-linked haemoglobin on the oxygen reserve in a rodent model of surgical blood loss.

The efficacy of pre-operative haemodilution is limited by the reduction in haemoglobin concentration. Acellular haemoglobin-based oxygen carriers provide an alternative to colloid as a haemodiluent, potentially extending the safe limits of this procedure. The aim of this investigation was to determine whether haemodilution with a cross-linked haemoglobin solution, diaspirin cross-linked haemoglobin solution (DCLHb), would enhance the oxygen reserve compared to pentastarch. Sprague Dawley rats were placed in a metabolic box to directly measure systemic oxygen consumption (VO2). Rats were randomized to be haemodiluted to a cellular haemoglobin of 80 g L(-1) with either DCLHb or pentastarch. Oxygen reserve was assessed during isovolemic haemorrhage by determining the critical oxygen delivery (DO2crit) and haemoglobin concentration at the point of oxygen supply dependency (OSD). Following haemodilution and for the duration of the experiment, cardiac index (CI) was significantly lower and systemic vascular resistance was significantly higher in the DCLHb than the pentastarch group. The DO2crit (3.2 +/- 0.4 mL minAg(-1) and 3.4 +/- 0.5 mL minAg(-1), DCLHb versus pentastarch) and cellular haemoglobin concentration (51 +/- 9 g L(-1) and 48 +/- 9 g L(-1)), at which rats entered OSD were similar in both groups. Total haemoglobin concentration (cellular and plasma DCLHb) and arterial oxygen content were significantly higher in the DCLHb group (total haemoglobin, 66 +/- 8 g L(-1) and arterial content, 9.2 +/- 1.4 mL dL(-1)) compared to the pentastarch group (total haemoglobin, 48 +/- 9 g L(-1) and arterial content, 7.3 +/- 1.4 mL dL(-1)). Oxygen extraction ratios increased from baseline levels to 0.53 +/- 0.07 and 0.56 +/- 0.1, for the DCLHb and pentastarch groups, respectively, and were not significantly different. The increase in arterial oxygen content from DCLHb in plasma was offset by the decrease in CI observed in this group. Plasma DCLHb did not extend the limits of haemodilution beyond the capacity of the cellular haemoglobin concentration.

[Creation of emergency care services in developing countries: luxury or necessity?]. / Creer un service d'aide medicale d'urgence dans un pays en developpement: luxe ou necessite?

Organization of emergency care services prior to hospital admission has progressed at a satisfactory pace in developed countries. A performance model in this field is the French emergency service called service d'aide médicale d'urgence (SAMU). Socioeconomic conditions prevailing in developing countries have pushed authorities to give priority to preventive medicine. However numerous patients especially young people and women during childbirth die as a result of inadequate facilities for transportation from hospitals and dwellings in outlying areas to major medical centers where the best medical equipment and staff are available. As a result, it may be asked if emergency care services is really a luxury. The authors base their conclusion on analysis of the conditions and outcome of emergency patient care in three African countries in which it is essentially a requirement.

Effect of prophylactic transfusion of stored RBCs on oxygen reserve in response to acute isovolemic hemorrhage in a rodent model.

BACKGROUND: The storage of RBCs results in a time-related decline in 2,3 DPG that may reduce the ability to unload oxygen (O(2)) to tissue. The objective of this study was to compare the effect that transfusion of stored 2,3 DPG-depleted rat blood (7 days in CPDA-1) had on the O(2) reserve in conscious rats, with that of the transfusion of fresh blood (<2-hour storage). STUDY DESIGN AND METHODS: Anemic rats (Hb, 80 g/L) received either fresh packed RBCs or stored RBCs to raise Hb levels to 140 g per L. They then underwent isovolemic hemorrhage mimicking surgical blood loss to the point of O(2) supply dependency (OSD). Critical O(2) delivery (DO(2)crit), Hb concentration, and O(2) extraction at OSD were measured in a metabolic chamber. RESULTS: After transfusion, RBC DPG decreased by 50 percent in the stored-blood group, and the p50 value decreased by 5 mmHg (32.1 +/- 2.5 mmHg vs. 37.5 +/- 3.0). DO(2)crit was similar in the two groups (fresh blood: 2.79 +/- 0.44 mL/min x g(-1); stored blood, 2.99 +/- 0.76 mL/min x g(-1)). The critical Hb concentration at DO(2)crit was higher in the stored-blood group (44 +/- 4 g/L) than in the fresh-blood group (38 +/- 5 g/L); the cardiac index and O(2) extraction ratio in the two groups were not different. Under conditions of severe normovolemic anemia in rats, depletion of DPG and a decrease in p50 had only minor effects on the O(2) reserve. At OSD, under these conditions, O(2) consumption is not limited by diffusion. CONCLUSION: The physiologic impact of DPG depletion in transfused stored blood on oxygen availability in normal rats appears to be small and may be clinically inconsequential.

A comparison of biochemical and functional alterations of rat and human erythrocytes stored in CPDA-1 for 29 days: implications for animal models of transfusion.

Animal models of transfusion are employed in many research areas yet little is known about the storage-related changes occurring in the blood used in these studies. This study assessed storage-related changes in red blood cell (RBC) biochemistry, function and membrane deformability in rat and human packed RBCs when stored in CPDA-1 at 4 degrees C over a 4-week period. Human blood from five volunteers and five bags of rat RBC concentrates (five donor rats per bag) were collected and stored at 4 degrees C. RBC function was assessed by post-transfusion viability and the ability to regenerate adenosine triphosphate (ATP) and 2,3-diphosphoglycerate (DPG) when treated with a rejuvenation solution. Membrane deformability was determined by a micropipette aspiration technique. ATP in rat RBCs declined more rapidly than human RBCs; after 1 week rat ATP fell to the same level as human cells after 4 weeks of storage (rat, 2.2 +/- 0.2 micromol g(-1) Hb; human, 2.5 +/- 0.3 micromol g(-1) Hb). Baseline DPG concentrations were similar in rat and human RBCs (16.2 +/- 2.3 micromol g(-1) Hb and 13.7 +/- 2.4 micromol g(-1) Hb) and declined very rapidly in both species. Human RBCs fully regenerated ATP and DPG when treated with a rejuvenation solution after 4 weeks of storage. Rat RBCs regenerated ATP but not DPG. Post-transfusion viability in rat cells was 79%, 26% and 5% after 1, 2 and 4 weeks of storage, respectively. In rats, decreased membrane deformability became significant (- 54%) after 7 days. Human RBC deformability decreased significantly by 34% after 4 weeks of storage. The rejuvenation solution restored RBC deformability to control levels in both species. Our results indicate that rat RBCs stored for 1 week in CPDA-1 develop a storage lesion similar to that of human RBCs stored for 4 weeks and underscores significant species-specific differences in the structure and metabolism of these cells.

Effects of FI(O(2)) on hemodynamic responses and O(2) transport during RSR13-induced reduction in P(50).

Reduced Hb-O(2) affinity facilitates O(2) release to tissue but may impair pulmonary O(2) uptake, affecting cardiac output and systemic vascular resistance (SVR). We studied the effects of shifting the O(2)-dissociation curve (ODC) to the right with a continuous infusion of RSR13, an allosteric modifier of Hb, and of different inspired O(2) fractions (FI(O(2))) on arterial O(2) saturations (Sa(O(2))) in Hb and on hemodynamics in nonanesthetized rats. At an FI(O(2)) of 0.21, Sa(O(2)) fell during RSR13 from 95 to 81%. Elevation of FI(O(2)) to 0.30 returned Sa(O(2)) to baseline in the RSR13 group. The decrease in mean arterial pressure (MAP) was significantly greater in the control than in the RSR13 group at 30% O(2). Cardiac index (CI) increased only during RSR13 at 21% O(2) and returned to baseline at 30% O(2). In contrast, SVR decreased after RSR13 was infused at 21% O(2) but returned to baseline at 30%O(2), whereas controls showed the opposite, a sustained SVR. In the follow-up period, when 21 O(2)% was reestablished and mild anemia was present, MAP and SVR fell significantly more in controls, whereas CI only increased in controls. Lactate was significantly lower in the RSR13 than in the control group during RSR13 and the follow-up period. These results demonstrate that 1) continuous infusion of RSR13 produces a constant shift in the O(2) tension at which Hb is 50% saturated (P(50)), 2) FI(O(2)) of 0.30 compensates for the effects of increased P(50) on pulmonary O(2) loading, and 3) right-shifted ODC combined with supplemental O(2) may improve tissue O(2) availability.

[Histopathology of Anopheles gambiae s.l. Giles, 1902 (Diptera, Culicidae) subjected to the larvicidal activity of the aqueous extract of Persea americana Miller, 1768 (Lauraceae)]. / Histopathologie d'Anopheles gambiae s.l. Giles, 1902 (Diptera, Culicidae) soumis à l'activité larvicide de l'extrait aqueux de Persea americana Miller, 1768 (Lauraceae).

Larvae of Anopheles gambiae treated with an aqueous extract of Persea americana suffer important damages of the midgut. The first epithelial cells to be affected are those at the posterior part of the midgut which become hypertrophic after only 30 min. After one hour most of the cells in this part lyse. The cytoplasmic material is then rejected towards the lumen gut, between the peritrophic membrane and the midgut epithelium. Subsequently, an almost total cell degeneration is observed. Cells of gastric caeca and cells at the intermediary and anterior parts of the midgut undergo the same histopathology, albeit after a longer period.

Influence of sepsis on the plasma elimination pharmacokinetics of diaspirin crosslinked hemoglobin in rats.

Septic shock is characterized by abnormalities in microcirculatory O2 delivery (QO2) and profound tissue O2 debt. Administration of crosslinked hemoglobin may be a means of augmenting the QO2 and tissue O2 availability. Sepsis is associated with hemodynamic and metabolic alterations which may affect the pharmacokinetics of crosslinked hemoglobin. The objective of this study was to determine the effect of sepsis on the plasma elimination of diaspirin crosslinked hemoglobin (DCLHb). Twenty-four hours after the induction of sepsis by cecal ligation and perforation, septic (n = 9) and sham rats (n = 8) received an intravenous infusion of 300 mg of DCLHb and arterial blood samples were taken at regular intervals to determine free plasma hemoglobin concentration. DCLHb elimination in septic and sham rats was consistent with first-order elimination kinetics. The half life (t1/2) for septic rats was 4.2 +/- 0.7 h and was significantly shorter than the t1/2 of non-septic rats (5.4 +/- 0.9 h). In all rats, free plasma hemoglobin returned to basal levels by 24 hours after DCLHb administration. The volume of distribution for DCLHb in the septic and non-septic rats was not significantly different and suggests that DCLHb is not influenced by altered gut permeability. Despite significant changes in some elimination parameters the differences were small. Consequently, dosing regimens for this compound may not need to be altered in sepsis.

The red cell storage lesion and its implication for transfusion.

Storage of red blood cells in preservative medium is associated with metabolic, biochemical and molecular changes to erythrocytes collectively referred to as the "storage lesion." In addition to corpuscular injury, bioreactive substances including cytokines and lipids accumulate in the medium during storage. We review evidence for those storage related changes and potential clinical implications for red blood cell transfusion.

Validation of transit-time ultrasound flow probes to directly measure portal blood flow in conscious rats.

Direct measurement of portal venous blood flow is technically difficult, yet crucial for accurate assessment of liver hemodynamic and metabolic functions. The aim of this investigation was to assess the feasibility of implanting transit-time ultra-sound (TTUS) perivascular flow probes on the portal vein of the rat and to validate this technique as a means of directly measuring portal blood flow in conscious rats. A TTUS flow probe was implanted on the portal veins of 10 rats. One week later, portal flow was measured under basal conditions in these rats by TTUS probes and after pharmacological manipulation of portal flow by intravenous injections of Glypressin or infusions of adenosine while the rats were conscious. Portal flow was simultaneously measured in the same rats using radioactive microspheres. Basal systemic hemodynamics, regional blood flows to splanchnic organs, and portal blood pressure were not significantly modified by the presence of the probe on the portal vein compared with a control group of rats not instrumented with flow probes. Basal portal flows measured by the TTUS and microsphere techniques were not different (20.6 +/- 2.6 and 17.6 +/- 1.3 ml/min). After Glypressin, portal flows measured by the TTUS and microsphere techniques were 12.3 +/- 2.9 and 9.3 +/- 1.9 ml/min and, in response to adenosine, increased to 27.2 +/- 3.4 and 31.3 +/- 4.1 ml/min. There was no significant difference between the TTUS and microsphere flows. Both the relationship between absolute flows and the relationship between changes in flows measured by the two techniques were linear with slopes approaching 1.0. Thus TTUS flow probes can be used to directly measure portal flow from the portal vein in conscious rats. This methodology is as effective as the standard technique of radioactive microspheres. More importantly, the TTUS technique allows for continuous direct measurement of portal flow and eliminates the hazards and sources of error associated with the radioactive microsphere technique.