Health professionals prepared for the future. Why Social Sciences and Humanities teaching in Medical Faculties matter

This article was migrated. The article was marked as recommended. A public debate took place place in France in 2018 concerning ethical and social issues of biomedicine and life science and technologies. As faculty members of French medical schools and scholars in Social Sciences and Humanities, we contributed to introduce the central theme of health professionals education. What roles and what place should we assign to the social sciences and Humanities in preparing health professionals who will work in a transforming and largely unpredictable context? In this paper, we list 4 crucial issues for the present and the future of healthcare profession, concerning changes of medical roles; new biomedical concepts and innovations; long term consequences on health social contract; ethical issues in health care daily life settings. Then, we list 4 kinds of resources that are brought to students by Social Sciences and Humanities courses. They concern the connection to patients's experiences the social and cultural construction of these experiences; the social responsibility of medical doctors; and the independence of their professional judgments. This is a plea for the development of reflexivity and critical thought backed up by well identified, well integrated and sufficiently developed Social Sciences and Humanities courses in French medical schools.

MRI measurement of the canine auditory pathways and relationship with brainstem auditory evoked responses

The objective of this study was to determine direct measurements of auditory pathways by magnetic resonance imaging (MRI) during the growth period of healthy Beagles, and to discover how canine brainstem auditory evoked response (BAER) latencies vary in relation to these MRI measurements. Eighty healthy Beagles were tested at eight, 16 and 52 weeks of age (stages 1, 2, 3, respectively) with BAER and brain MRI. The BAER interpeak latency (IPL) II-V and brain MRI neural generators of BAER waves II and V were identified. A linear distance was calculated in millimeters in order to determine the approximate length of auditory pathways. Sensory nerve conduction velocity (SNCV) of the auditory pathway between peak II and peak V was calculated for each group. A significant difference was observed between brain MRI distances among the three stages. Mean BAER IPL II-V were not significantly different between the three stages. The progressive growth of the skull and brain witnessed by the progressive increased distance of the MRI auditory pathways between peak II and peak V was not associated with a progressive maturation of the BAER IPL II-V. The SNCV of the auditory pathway between peak II and peak V was 6.14 m/sec for group 1; 6.76 m/sec for group 2; and 7.32 m/sec for group 3.

[The positive culture of error, historical, epistemological and ethical aspects]

The punitive culture of error erects a wall of silence between players in the care relationship. A positive culture of error, founded on a new ethical approach to the nurse-patient relationship, enables everyone to move beyond the illusion of medical infallibility and to cope better with the effects of an adverse event.

Accuracy, intermethod agreement, and inter-reviewer agreement for use of magnetic resonance imaging and myelography in small-breed dogs with naturally occurring first-time intervertebral disk extrusion

OBJECTIVE

To determine accuracy, intermethod agreement, and inter-reviewer agreement for multisequence magnetic resonance imaging (MRI) and 2-view orthogonal myelography in small-breed dogs with first-time intervertebral disk (IVD) extrusion.

DESIGN

Prospective evaluation study.

ANIMALS

24 dogs with thoracolumbar IVD extrusion.

PROCEDURES

Each dog underwent MRI and myelography. Images obtained with each modality were independently evaluated and assigned standardized scores in a blinded manner by 3 reviewers. Results were compared with surgical findings. Inter-reviewer and intermethod agreements were assessed via κ statistics. Accuracy was assessed as the percentage of dogs for which ≥ 2 of 3 reviewers recorded findings identical to those determined surgically.

RESULTS

Inter-reviewer agreement was substantial for site (κ = 0.70) and side of IVD extrusion (κ = 0.62) in T2-weighted magnetic resonance images and was substantial for site (κ = 0.72) and fair for side of extrusion (κ = 0.37) in myelographic images. Agreement for site between each modality and surgical findings was near perfect (κ = 0.94 and 0.88 for MRI and myelography, respectively). Intermethod agreement was substantial for site (κ = 0.71) and moderate for side of extrusion (κ = 0.40). Accuracy of MRI for site and side was 100% when results for T1-weighted, T2-weighted, and contrast-enhanced T1-weighted sequences were combined. Accuracy of myelography was 90.9% and 54.5% for site and side, respectively.

CONCLUSIONS AND CLINICAL RELEVANCE

Agreement between imaging results and surgical findings for identification of IVD extrusion sites in small-breed dogs was similar for MRI and myelography. However, MRI appeared to be more accurate than myelography and allowed evaluation of extradural compressive mass composition.

Investigation of the use of three electroencephalographic electrodes for long-term electroencephalographic recording in awake and sedated dogs

OBJECTIVE

To compare electroencephalography (EEG) artifact associated with use of the subdermal wire electrode (SWE), gold cup electrode (GCE), and subdermal needle electrode (SNE) over an 8-hour period in sedated and awake dogs.

ANIMALS

6 healthy dogs.

PROCEDURES

8 EEG channels were recorded during 20-minute video-EEG recording sessions (intermittently at 0.5, 2, 4, 6, and 8 hours) with and without chlorpromazine sedation. Nonphysiologic artifacts were identified. Duration of artifact was summed for each channel. Number of unaffected channels (NUC) was determined.

RESULTS

NUC was significantly affected by electrode type and sedation over time; median for SWE (2.80 channels; 95% confidence interval [CI], 0.84 to 5.70 channels) was significantly different from medians for GCE (7.87 channels; 95% CI, 7.44 to 7.94 channels) and SNE (7.60 channels; 95% CI, 6.61 to 7.89 channels). After 4 hours, NUC decreased in awake dogs, regardless of electrode type. In awake dogs, duration of artifact differed significantly between SWE and GCE or SNE; medians at 8 hours were 61.55 seconds (95% CI, 21.81 to 173.65 seconds), 1.33 seconds (95% CI, 0.47 to 3.75 seconds), and 21.01 seconds (95% CI, 6.85 to 64.42 seconds), respectively.

CONCLUSIONS AND CLINICAL RELEVANCE

The SWE had a significant duration of artifact during recording periods > 2 hours, compared with results for the GCE and SNE, in awake dogs. The GCE, SNE, and sedation resulted in significantly more channels unaffected by artifact. For longer recordings, caution should be exercised in selecting EEG electrodes and sedation state, although differences among electrodes may not be clinically relevant.

Effects of hypercapnia, hypocapnia, and hyperoxemia on brain morphometrics determined by use of T1-weighted magnetic resonance imaging in isoflurane-anesthetized dogs

OBJECTIVE

To evaluate the effects of various combinations of PaCO2 and PaO2 values on brain morphometrics.

ANIMALS

6 healthy adult dogs.

PROCEDURES

A modified Latin square design for randomization was used. Dogs were anesthetized with propofol (6 to 8 mg/kg, IV), and anesthesia was maintained with isoflurane (1.7%) and atracurium (0.2 mg/kg, IV, q 30 min). Three targeted values of PaCO2 (20, 40, and 80 mm Hg) and 2 values of PaO2 (100 and 500 mm Hg) were achieved in each dog, yielding 6 combinations during a single magnetic resonance (MR) imaging session. When the endpoints were reached, dogs were given at least 5 minutes for physiologic variables to stabilize before T1-weighted MR images were obtained. Total brain volume (TBV) and lateral ventricular volume (LVV) were calculated from manually drawn contours of areas of interest by use of a software program, with each dog serving as its own control animal. Three blinded investigators subjectively evaluated the lateral ventricular size (LVS) and the cerebral sulci width (CSW). Brain morphometric values were compared among the target blood gas states.

RESULTS

No significant differences in TBV were found among target states. The LVV was significantly greater during hypocapnia, compared with hypercapnia at the same PaO2 value. With regard to the subjective evaluations, there were no significant differences among evaluators or among combinations of PaO2 and PaCO2 values.

CONCLUSIONS AND CLINICAL RELEVANCE

The changes observed in LVV during hypocapnia and hypercapnia may serve as a potential confounding factor when neuromorphometric evaluations are performed in anesthetized dogs.

Thymoma-associated exfoliative dermatitis with post-thymectomy myasthenia gravis in a cat

Thymoma-associated exfoliative dermatitis was suspected in a cat with a cranial mediastinal mass. The dermatopathy resolved with surgical removal of a thymoma. The cat manifested neurologic signs consistent with myasthenia gravis 7 wk after surgery. Exfoliative dermatitis and post-thymectomy myasthenia gravis in the same cat has not been reported previously.

Effects of hypercapnia, hypocapnia, and hyperoxemia on blood oxygenation level-dependent signal intensity determined by use of susceptibility-weighted magnetic resonance imaging in isoflurane-anesthetized dogs

OBJECTIVE

To assess the effects of alterations in PaCO(2) and PaO(2) on blood oxygenation level-dependent (BOLD) signal intensity determined by use of susceptibility-weighted magnetic resonance imaging in brains of isoflurane-anesthetized dogs.

ANIMALS

6 healthy dogs.

PROCEDURES

In each dog, anesthesia was induced with propofol (6 to 8 mg/kg, IV) and maintained with isoflurane (1.7%) and atracurium (0.2 mg/kg, IV, q 30 min). During 1 magnetic resonance imaging session in each dog, targeted values of PaCO(2) (20, 40, or 80 mm Hg) and PaO(2) (100 or 500 mm Hg) were combined to establish 6 experimental conditions, including a control condition (PaCO(2), 40 mm Hg; PaO(2), 100 mm Hg). Dogs were randomly assigned to different sequences of conditions. Each condition was established for a period of >or= 5 minutes before susceptibility-weighted imaging was performed. Signal intensity was measured in 6 regions of interest in the brain, and data were analyzed by use of an ANCOVA and post hoc Tukey-Kramer adjustments.

RESULTS

Compared with control condition findings, BOLD signal intensity did not differ significantly in any region of interest. However, signal intensities in the thalamus and diencephalic gray matter decreased significantly during both hypocapnic conditions, compared with all other conditions except for the control condition.

CONCLUSIONS AND CLINICAL RELEVANCE

In isoflurane-anesthetized dogs, certain regions of gray matter appeared to have greater cerebrovascular responses to changes in PaCO(2) and PaO(2) than did others. Both PaO(2) and PaCO(2) should be controlled during magnetic resonance imaging procedures that involve BOLD signaling and taken into account when interpreting findings.

Peptidylarginine deiminase 2 (PAD2) overexpression in transgenic mice leads to myelin loss in the central nervous system

Demyelination in the central nervous system is the hallmark feature in multiple sclerosis (MS). The mechanism resulting in destabilization of myelin is a complex multi-faceted process, part of which involves deimination of myelin basic protein (MBP). Deimination, the conversion of protein-bound arginine to citrulline, is mediated by the peptidylarginine deiminase (PAD) family of enzymes, of which the PAD2 and PAD4 isoforms are present in myelin. To test the hypothesis that PAD contributes to destabilization of myelin in MS, we developed a transgenic mouse line (PD2) containing multiple copies of the cDNA encoding PAD2, under the control of the MBP promoter. Using previously established criteria, clinical signs were more severe in PD2 mice than in their normal littermates. The increase in PAD2 expression and activity in white matter was demonstrated by immunohistochemistry, reverse transcriptase-PCR, enzyme activity assays, and increased deimination of MBP. Light and electron microscopy revealed more severe focal demyelination and thinner myelin in the PD2 homozygous mice compared with heterozygous PD2 mice. Quantitation of the disease-associated molecules GFAP and CD68, as measured by immunoslot blots, were indicative of astrocytosis and macrophage activation. Concurrently, elevated levels of the pro-inflammatory cytokine TNF-alpha and nuclear histone deimination support initiation of demyelination by increased PAD activity. These data support the hypothesis that elevated PAD levels in white matter represents an early change that precedes demyelination.

A case of primary hypothyroidism causing central nervous system atherosclerosis in a dog

A 2-year-old, castrated male, Australian shepherd was presented with a history of chronic mild ataxia, obesity, and lethargy. The dog was treated with levothyroxine, but the ataxia worsened. Cranial nerve abnormalities developed and the dog was euthanized. Postmortem examination revealed marked thyroid gland atrophy and widespread, severe central nervous system atherosclerosis.

Ultrasound-guided fine needle aspiration in the diagnosis of peripheral nerve sheath tumors in 4 dogs

Ultrasound-guided fine needle aspiration was used in establishing the diagnosis in 4 cases of malignant peripheral nerve sheath tumor. Sonographic and cytologic characteristics are discussed. Because of its availability and ease of use, axillary ultrasonography with fine needle aspiration can be an initial diagnostic step for suspected brachial plexus tumors.

MRI measurement of the canine auditory pathways and relationship with brainstem auditory evoked responses

The objective of this study was to determine direct measurements of auditory pathways by magnetic resonance imaging (MRI) during the growth period of healthy Beagles, and to discover how canine brainstem auditory evoked response (BAER) latencies vary in relation to these MRI measurements. Eighty healthy Beagles were tested at eight, 16 and 52 weeks of age (stages 1, 2, 3, respectively) with BAER and brain MRI. The BAER interpeak latency (IPL) II-V and brain MRI neural generators of BAER waves II and V were identified. A linear distance was calculated in millimeters in order to determine the approximate length of auditory pathways. Sensory nerve conduction velocity (SNCV) of the auditory pathway between peak II and peak V was calculated for each group. A significant difference was observed between brain MRI distances among the three stages. Mean BAER IPL II-V were not significantly different between the three stages. The progressive growth of the skull and brain witnessed by the progressive increased distance of the MRI auditory pathways between peak II and peak V was not associated with a progressive maturation of the BAER IPL II-V. The SNCV of the auditory pathway between peak II and peak V was 6.14 m/sec for group 1; 6.76 m/sec for group 2; and 7.32 m/sec for group 3.

Human platelet lysate allows expansion and clinical grade production of mesenchymal stromal cells from small samples of bone marrow aspirates or marrow filter washouts

We compared two protocols for the expansion of human mesenchymal stromal cells (hMSCs) starting from diagnostic samples of BM aspirates (2-5 ml) or using the remnants in the bag and filter at the end of the BM infusions. The protocols differed in the presence of either 10% fetal bovine serum (FBS) or 5% platelet lysate (PL). We obtained a significantly (P=0.02) better expansion with PL, obtaining a median 1010-fold compared to 198-fold with a selected batch of FBS and in fewer days (29.8 in PL versus 41.4 in FBS). Overall, we recovered a variable number from 54.8 x 10(6) to 365 x 10(6) hMSCs in PL versus a variable number from 2.7 x 10(6) to 31 x 10(6) in FBS. No difference could be found in terms of gross morphology, differentiation potential, surface markers and immunological properties (inhibition of allogeneic PHA response and mixed lymphocyte reaction) of cells expanded with PL or FBS. The preparations were found within the range of acceptability for all the quality control criteria. Due to the clinical grade nature of the PL and the reproducibility of separate preparations, we propose this method to obtain hMSCs even from minute amounts of BM cells.

A novel mutation of the CLCN1 gene associated with myotonia hereditaria in an Australian cattle dog

BACKGROUND

Heritable myotonia is a genetic muscle disorder characterized by slow relaxation of skeletal muscles. The main clinical signs are skeletal muscle stiffness, especially after vigorous contraction, and muscle hypertrophy. Muscle stiffness may be enhanced by inactivity, and often is relieved by exercise. Myotonia can be inherited in an autosomal dominant or recessive manner (Thomsen- or Becker-type myotonia, respectively). In mice, goats, Miniature Schnauzer dogs, and most affected humans, the disorder is caused by mutations in CLCN1, which encodes the skeletal muscle voltage-gated chloride channel, Cl1C-1.

HYPOTHESIS

We hypothesized that an Australian Cattle Dog with generalized muscle stiffness and hypertrophy examined at the Ontario Veterinary College would have a mutation in the CLCN1 gene.

ANIMALS

A pure-bred Australian Cattle Dog from Ontario, Canada, was used.

METHODS

Based on clinical signs and electromyographic test results, a diagnosis of myotonia hereditaria was made, and a muscle biopsy was collected for genetic analysis.

RESULTS

Sequence data obtained from the affected dog confirmed that it was homozygous for a single base insertion in the CLCN1 coding sequence. This mutation would result in a truncated ClC-1 protein being expressed, which, based on molecular evidence from other studies, would result in functionally compromised chloride conduction in the skeletal muscles of the animal.

CONCLUSIONS AND CLINICAL IMPORTANCE

To the authors' knowledge, this report describes the Ist case of myotonia in an Australian Cattle Dog and represents the 1st non-Schnauzer canine myotonia to be genetically characterized. In addition, we developed a polymerase chain reaction-based genetic screen to detect heterozygotes with this mutation in the at-large Australian Cattle Dog population.

Correlation of motor evoked potentials with magnetic resonance imaging and neurologic findings in Doberman Pinschers with and without signs of cervical spondylomyelopathy

OBJECTIVE

To establish the reference ranges for motor evoked potential (MEP) latency and amplitude in clinically normal Doberman Pinschers, compare the MEPs of Doberman Pinschers with and without clinical signs of cervical spondylomyelopathy (CSM; wobbler syndrome), and determine whether MEP data correlate with neurologic or magnetic resonance imaging (MRI) findings.

ANIMALS

16 clinically normal and 16 CSM-affected Doberman Pinschers.

PROCEDURES

Dogs were classified according to their neurologic deficits. After sedation with acepromazine and hydromorphone, transcranial magnetic MEPs were assessed in each dog; latencies and amplitudes were recorded from the extensor carpi radialis and cranial tibial muscles. Magnetic resonance imaging was performed to evaluate the presence and severity of spinal cord compression.

RESULTS

Significant differences in cranial tibial muscle MEP latencies and amplitudes were detected between clinically normal and CSM-affected dogs. No differences in the extensor carpi radialis MEP were detected between groups. There was a significant correlation (r = 0.776) between the cranial tibial muscle MEP latencies and neurologic findings. Significant correlations were also found between MRI findings and the cranial tibial muscle MEP latencies (r = 0.757) and amplitudes (r = -0.453).

CONCLUSIONS AND CLINICAL RELEVANCE

Results provided a reference range for MEPs in clinically normal Doberman Pinschers and indicated that cranial tibial muscle MEP latencies correlated well with both MRI and neurologic findings. Because of the high correlation between cranial tibial muscle MEP data and neurologic and MRI findings, MEP assessment could be considered as a screening tool in the management of dogs with spinal cord disease.

Electroencephalographic recording during transcranial magnetic stimulation in humans and animals

OBJECTIVE

We report on the development of an EEG recording system, comprised of electrodes and amplifiers that are compatible with TMS (single and rapid-rate) in both human and animal studies.

METHODS

We assembled a versatile multi-channel EEG recording system consisting of: (1) two types of electrodes that are safe during TMS or rTMS. (2) Low slew-rate EEG amplifiers that recover within a few milliseconds after the application of TMS pulses.

RESULTS

The two electrode types: (a) a conductive-plastic surface electrode with a conductive-silver epoxy coat and (b) a subdermal silver wire electrode (SWE) are compatible to TMS pulses. The amplifiers recover within 30 ms, so that the EEG can be viewed online, essentially without interruption and/or blocking or excessive artifact.

CONCLUSIONS

Our TMS compatible electrode and EEG recording system allows safe and online viewing/recording of the subject's (human or animal) EEG/EP during experiments or studies involving TMS or rTMS applications. The TMS compatible electrode/amplifier system can be used with any EEG recording instrument.

SIGNIFICANCE

A simple recording technique coupled with new electrodes permit safe and readable EEG records during TMS in humans and animals. Such online monitoring of the EEG would allow control of TMS/rTMS parameters based on EEG activity.

Cervical syringohydromyelia secondary to a brainstem tumor in a dog

An 11-year-old male Pekingese was evaluated because of a history of head tilt. Neurologic examination revealed a right-sided head tilt, ataxia, scoliosis, and proprioceptive deficits. Diagnostic testing included magnetic resonance imaging (MRI) of the head and neck. After IV administration of gadopentetate dimeglumine, an extra-axial, highly contrast-enhanced mass in the brainstem, cerebellar herniation, and syringohydromyelia were detected via MRI. The dog was treated with corticosteroids and radiation therapy of the mass for 4 weeks (total dose, 42.5 Gy). Magnetic resonance imaging was repeated 9 weeks and 6 months after radiation therapy; compared with the initial findings, a reduction in the size of the brainstem mass was observed in both MRI scans. The third MRI scan also revealed a normal cerebellar shape, no evidence of herniation, and resolution of syringohydromyelia in the dog at that time. It is recommended that whenever syringohydromyelia is observed via MRI, a primary cause (cranial or caudal to the affected region) should be sought.

West Nile virus encephalomyelitis in horses in Ontario: 28 cases

West Nile virus encephalomyelitis was diagnosed in 28 horses presented to the Ontario Veterinary College Veterinary Teaching Hospital between August 20 and October 15, 2002. The age range of affected horses was 5 months to 20 years (mean 6.9 years, median 6 years). Clinical signs were highly variable. Duration of hospitalization ranged from < 1 to 12 days (mean 5 days, median 5.4 days). Overall, 16 of the 28 (57%) horses were discharged and, of the 14 from which follow-up information was available, 13 (93%) were reported to be clinically normal 4 to 6 weeks following discharge, while the other horse had markedly improved. This pathogen is emerging as an important cause of neurological disease in Canada.

Correlation between severity of clinical signs and motor evoked potentials after transcranial magnetic stimulation in large-breed dogs with cervical spinal cord disease

OBJECTIVE

To evaluate use of transcranial magnetic motor evoked potentials for assessment of the functional integrity of the cervical spinal cord in large-breed dogs with cervical spinal cord disease.

DESIGN

Randomized, controlled, masked study.

ANIMALS

10 healthy large-breed control dogs and 25 large-breed dogs with cervical spinal cord diseases.

PROCEDURE

Affected dogs were allocated to 3 groups on the basis of neurologic status: signs of neck pain alone, ambulatory with ataxia in all limbs, or nonambulatory. Transcranial magnetic stimulation was performed on each dog with the same standard technique. Motor evoked potentials (MEP) were recorded from electrodes inserted in the tibialis cranialis muscle. Following the procedure, each dog was anesthetized and cervical radiography, CSF analysis, and cervical myelography were performed. The MEP latencies and amplitudes were correlated with neurologic status of the dogs after correction for neuronal path length.

RESULTS

Mean MEP latencies and amplitudes were significantly different between control dogs and dogs in each of the 3 neurologic categories, but were not significantly different among dogs in the 3 neurologic categories. A linear association was evident between MEP latencies and amplitudes and severity of neurologic deficits; the more severe the neurologic deficits, the more prolonged the latencies and the more decreased the amplitudes.

CONCLUSIONS AND CLINICAL RELEVANCE

Transcranial magnetic MEP are useful to assess severity of cervical spinal cord disease in large-breed dogs. Impairment of the functional integrity of the cervical spinal cord was found even in dogs with neck pain alone.

Erythropoietin therapy and preoperative autologous blood donation in children undergoing open heart surgery

We assessed the feasibility and efficacy of subcutaneous erythropoietin alpha (EPO) therapy and preoperative autologous blood donation (ABD) in children undergoing open heart surgery. Thirty-nine children were treated consecutively with EPO (100 U x kg(-1) s.c. three times a week in the 3 weeks preceding the operation and i.v. on the day of surgery) and two ABDs were made (Group 1). As controls to compare transfusion requirements, 39 consecutive age-matched patients who had undergone open heart surgery during the two preceding years were selected (Group 2). In a mean time of 20 (SD 5) days, 96% of scheduled ABDs were performed and only three mild vasovagal reactions were observed. The mean volume of autologous red blood cells (RBC) collected was 6 (1) ml x kg(-1) and the mean volume of autologous RBC produced as a result of EPO therapy before surgery was 7 (3) ml x kg(-1), corresponding to a 28 (11)% increase in circulating RBC volume. The mean volume of autologous RBC collected was not different from that produced [6 (1) vs 7 (3) ml x kg(-1), P=0.4]. Allogenic blood was administered to three out of 39 children in Group 1 (7.7%) and to 24 out of 39 (61.5%) in Group 2. Treatment with subcutaneous EPO increases the amount of autologous blood that can be collected and minimizes allogenic blood exposure in children undergoing open heart surgery.

Transfusion-transmitted virus infection in HIV-1-seropositive patients

OBJECTIVES

To investigate the prevalence, persistence and genome heterogeneity of transfusion-transmitted (TTV) in HIV-1-infected patients, a group at high risk both of contracting blood-borne viruses and having viral persistence relating to immunodepression.

METHODS

Plasma samples from 238 HIV-1 seropositive subjects and 226 healthy blood donors were examined for TTV-DNA both by polymerase chain reaction (PCR) using primers from the conserved regions in the N22 clone and PCR using primers deduced from the untranslated region (UTR). Direct DNA sequencing and phylogenetic analysis were used to characterize 27 TTV isolates from HIV-1 patients or healthy controls.

RESULTS

Using PCR with the UTR primers, TTV DNA was detected in a very high percentage (> 80%) of samples both from HIV-1 seropositive subjects and from blood donors. Using PCR with N22 primers, shown to detect viral strains associated with hepatitis of unknown etiology, TTV DNA was found in 103 of 238 (43.3%) HIV-1-infected patients and in 22 of 226 (9.7%) blood donors. There was no difference in the prevalence of the TTV DNA in HIV seropositive subjects with regard to clinical features related to immunosuppression, markers of HCV infection or intravenous drug use; presence of TTV DNA was associated significantly only with male gender (P = 0.003). Persistent or intermittent viremia was detected in plasma samples taken up over a period of 19 months in all (15 of 15) HIV-infected patients tested.

CONCLUSIONS

The persistence and high frequency of infection detected by PCR with N22 primers in HIV-1 seropositive patients suggest that further clinical investigation of immunocompromised hosts will provide information to clarify the pathogenic role of TTV.

Comparison of performance of six different cell separators in collecting peripheral blood mononuclear cells

We compared the efficacy of six different cell separators in collecting peripheral mononuclear cells to be used for autologous or homologous peripheral stem cell transplantation. The product obtained with the Dideco Vivacell cell separator showed a low percentage of mononuclear cells (38%) in the final product and a high platelet efficiency (38%). The Baxter CS3000 Plus cell separator required the longest time to load and prime the kit (18 min), it showed a high MNC efficiency (68%), with the highest percentage of MNC in the final product, the highest platelet efficiency (45%), a low red blood cell contamination in the final product (2.7 mL), the highest extracorporeal volume (450 mL) and a high percentage of technical failures (15%). The product obtained with the Fresenius AS104 cell separator with P1Y kit showed the highest final volume (297 mL), the lowest platelet efficiency (12%) and the lowest extracorporeal volume (230 mL). The same cell separator with C4Y kit showed a lower MNC efficiency (52 vs 60%) and a higher percentage of MNC in final product (63 vs 41%). The platelet contamination in final product was the lowest (18 x 10(9)/100 mL). The Haemonetics MCS3p cell separator required the lowest time to load and prime the kit (5 min), it showed the highest MNC efficiency (71%). The blood volume processed per hour (1328 mL) and the percentage of MNC in final product was lowest (32%), the extracorporeal volume (450 mL) was the highest. The Cobe Spectra cell separator allowed to process the highest blood volume per hour (3383 mL) and the final product had the lowest red blood cell contamination (2.3 mL/100 mL). The Dideco Excel cell separator required the longest time to load and prime the kit (18 min), the lowest MNC efficiency (38%), the highest platelet contamination in final product. Furthermore this machine showed the highest percentage of technical failure (20%). None of the six instruments have all the required preconditions and the ideal cell separator for peripheral stem cell apheresis at present is not available on the market.

HCV transmission in family members of subjects with HCV related chronic liver disease

To investigate the risk of sexual and intrafamilial transmission of HCV, 220 family members of 76 patients (index cases) with chronic type C viral liver disease were tested for serological markers of HCV. Of the family members, 129 were offspring, 64 sexual partners, 15 parents and 12 siblings of the index cases. Anti-HCV was tested in all the household contacts; HCV-RNA was tested in antibody positive samples. The serologic markers of HCV were tested in a control group of 168 family members of 81 patients with chronic hepatitis unrelated to HCV. The overall prevalence of anti-HCV was 8.2% compared to 0.6% in the control group (p < 0.001). Sexual partners were anti-HCV positive more frequently than the other contacts (20% vs 2.2%; p < 0.001), without any difference in males or females. No correlation was observed between the occurrence of HCV infection in contacts and age, severity of liver disease or risk factor for the acquisition of HCV in the index cases. Seven of the 18 (39%) anti-HCV positive family contacts had bio-chemical evidence of chronic liver disease, histologically confirmed in the 6 patients who underwent a liver biopsy. Liver chemistry was normal in all the HCV-negative contacts. Ten of the 18 anti-HCV positive contacts (55%) were HCV-RNA positive, Genotypes were the same (1b) in 4 of the 7 viremic couples of subjects: in 3 of the 6 couples of sexual partners and in the only mother/son couple. These data suggest the occurrence of intraspousal transmission of HCV, while intrafamiliar acquisition of HCV in non-sexual contacts seems to be rare.

Insulin regulation of glucose turnover and lipid levels in obese children with fasting normoinsulinaemia

To evaluate the early metabolic alterations induced by obesity, we studied glucose turnover and lipid levels in obese children with fasting normoinsulinaemia. Two experimental protocols were carried out. Protocol I consisted of a euglycaemic glucose clamp at two rates of insulin infusion. Protocol II was similar to protocol I except for a variable lipid infusion used to maintain basal non-esterified fatty acid (NEFA) levels. During protocol I, the glucose disappearance rates were lower in obese children, while no differences were found in hepatic glucose release. NEFA response to insulin was not substantially altered in obese children either at low or high insulin infusion. During protocol II, the NEFA clamp induced a 25% reduction in peripheral insulin sensitivity in control children whereas no changes were observed in obese children. Interestingly, lipid infusion in control children was not sufficient to reproduce the same degree of insulin resistance observed in obese children, suggesting that NEFA are only one of the determinants of insulin resistance at this stage of obesity. In conclusion, the present study provides a portrait of glucose metabolism and lipid levels in normoinsulinaemic obese children. Our results document that peripheral insulin resistance is the first alteration at this stage of obesity, whereas an increase in insulin secretion and a defect in the inhibition of hepatic glucose release by insulin may develop at a later stage. In addition, primarily receptor and post-receptor defects and some alterations of NEFA metabolism are likely to coexist in the induction of insulin resistance at this stage of obesity.

Intravenous infusion of diarginylinsulin, an insulin analogue: effects on glucose turnover and lipid levels in insulin-treated type II diabetic patients

Diarginylinsulin is an intermediate in the conversion of proinsulin to insulin and is usually present in small amounts in vivo in humans. This study was designed to evaluate the following in insulin-treated type II diabetic patients: (1) the feasibility of an overnight intravenous infusion of diarginylinsulin, as compared with an overnight intravenous infusion of short-acting insulin, and the degree of early morning glycemic control; and (2) the effects of diarginylinsulin and human insulin on hepatic glucose production (HGO) in the postabsorptive state and on the glucose turnover rate and peripheral insulin sensitivity during an euglycemic hyperinsulinemic clamp. Diarginylinsulin and regular human insulin maintained a comparable degree of normoglycemia during the night, without significant glucose increases in the morning. Free-diarginylinsulin and free-insulin concentrations were not significantly different, and (HGO) was 2.1 +/- 0.5 versus 2.1 +/- 0.4 mg/kg/min with diarginylinsulin and regular human insulin, respectively (NS). During the euglycemic clamp, glucose infusion rate per unit of diarginylinsulin or human insulin infused (M/I ratio) was similar, and HGO was equally suppressed with diarginylinsulin and regular human insulin. No significant differences were seen in NEFA and triglyceride levels. In conclusion, these results indicate that diarginylinsulin is as potent as regular human insulin; it is normalizes HGO in the postabsorptive state; and its hepatic and peripheral actions on glucose and lipids are comparable to those of human insulin during an euglycemic hyperinsulinemic clamp.

Determination of plasma [6,6-2H2]glucose enrichment by a simple and accurate gas chromatographic-mass spectrometric method

An improved method for the evaluation of glucose turnover rate in humans, using a prime-continuous infusion of [6,6-2H2]glucose, was developed. Deproteinization of plasma and conversion of glucose into the aldononitrile pentaacetate derivative are the only sample manipulations required prior to the gas chromatographic-mass spectrometric analysis. In six normal adults (prime = 5 mg kg-1; continuous infusion = 0.05 mg kg-1 min-1) the hepatic glucose output calculated at steady state by the procedure described here was 2.1 +/- 0.2 mg kg-1 min-1, the isotopic enrichment being determined with a coefficient of variation of ca. 2%. In six additional subjects, with half of the above-mentioned doses of labelled glucose, the mean hepatic glucose output was exactly the same (3.2% coefficient of variation for the isotopic enrichment measurement). The method described allows the hepatic glucose output to be precisely determined with savings both of time and of labelled glucose.

[Hypothalamo-pituitary-adrenal function in liver cirrhosis of viral etiology]

With the aim of evaluating the glucocorticoid function and the role of the adrenal gland in hypogonadism and feminization of cirrhotic patients, we examined 11 patients with virus-induced liver cirrhosis and 8 normal subjects as controls. In each subject serum levels of cortisol (C), progesterone (P), dehydroepiandrosterone (DHEA), dehydroepiandrosterone sulphate (DHEAS), delta 4-androstenedione (A), estrone (E1), testosterone (T), luteinizing hormone (LH) were assayed in basal conditions and after adrenocorticotropic hormone (ACTH) stimulation. Serum levels of ACTH, C, E1, estradiol (E2), T were assayed in basal condition and after dexamethasone suppression test. Moreover, a circadian study of ACTH, C and corticosteroid-binding globulin (CBG) was performed, with blood samples drawn at 8:00 and 20:00 on two consecutive days. Our results demonstrate that in cirrhosis: 1) normal levels of C, when metabolism is altered and CBG levels are reduced, are maintained by inhibition of ACTH secretion; 2) circadian rhythmicity of the pituitary-adrenal axis is well preserved; 3) in non-alcoholic cirrhosis, too, there is a reduction of androgens (T, DHEA, DHEAS, A) and a rise of estrogens (E2 and, more markedly, E1) and P; 4) in cirrhotic men E1 is mainly of adrenal origin and contributes, through negative feedback on LH secretion, to low levels of T.

[Evaluation of the activity of the bladder detrusor muscle and analysis of bladder function in subjects with diabetes mellitus under insulin treatment]

The present report concerns investigations of detrusor muscle adrenergic innervations in patients affected by bladder neuropathy secondary to diabetes without obstructive disturbances. Detrusor contractile activity evoked by NE is markedly reduced which can probably be attributed to receptor deficit. Urodynamic evaluation demonstrated a prevalence of sensory peripheral neuropathy than a motor conduction abnormality. In vitro study demonstrated that motor conduction abnormality of detrusor contractile activity is present early without bladder disturbances. Therefore early urodynamic measurements are necessary to evaluate bladder dysfunction and neuropathy in diabetic patients.