[Feasibility of a psychoeducation group for patients with anorexia nervosa: An open study]

INTRODUCTION

Management of anorexia nervosa is difficult and few treatments have shown their effectiveness, justifying the exploration of new therapeutic approaches. Available evidence suggests an interest of psychoeducational groups in a significant number of psychiatric disorders. In patients suffering from anorexia, to date there are few groups or interventions available. We aimed to assess the feasibility and acceptability of a psycho-educational program promoting information about the disease and presenting techniques that can help to cope with anorexia and the functional impact it causes. The exploratory secondary objectives were to evaluate if such a group is associated with clinical improvement.

METHOD

Twenty-seven patients suffering from anorexia nervosa, in three groups, received eight weekly interventions in addition to their usual care. The study was open-label and non-randomized. Patients were assessed three times (baseline, at the end of the group and three months later). The assessments were both qualitative (Eating Disorder Examination questionnaire, The Anorexia Nervosa Stage of Change Questionnaire, the Eating Disorders Quality of Life questionnaire, Work and Social Adjustment Scale) and qualitative.

RESULTS

Seventy-eight percent of participants attended more than 75 % of the sessions. Seventy percent of participants found the group useful, and 95 % said it helped them improve their knowledge of the disease and its consequences. The average BMI of participants changed significantly with an average increase of 2.5kg between baseline and the three month assessment. There was an improvement of the eating disorders features in EDE-Q for the total score and for all subscores. The improvement in the total score was significant at the end of the group sessions, while the improvement in the sub scores became significant at three months. There was also a significant mood improvement at the end of the group. Finally, there was a significant improvement in daily functioning with a decrease in Work and Social Adjustment Scale scores and an improvement in quality of life. On qualitative assessment, patients were satisfied with the care proposal. They were able to appreciate the support and sharing of experience provided by the group formula. Most of them reported changes in their daily lives, either in their relationship to care and illness, or in their relationships with their loved ones, their leisure/work, their mood or their eating behavior.

CONCLUSION

Both qualitative and quantitative results suggest that this group psychoeducation program is feasible and well accepted by patients in addition to usual management. Although the methodology does not allow any conclusions, the clinical improvements observed during the group are encouraging with regard to the safety of this type of intervention and its possible effectiveness and argue for a controlled study.

Use of a serious game to strengthen medication adherence in euthymic patients with bipolar disorder following a psychoeducational programme: A randomized controlled trial

BACKGROUND

Although psychoeducation programmes are the gold-standard intervention in bipolar disorder (BD), more innovative tools are needed to broaden and consolidate their effects, especially on treatment adherence. Serious games could be an option.

METHODS

We carried out a two-arm open randomized controlled trial to compare the add-on use of the serious game BIPOLIFE® for one month (n = 20) vs. treatment as usual (TAU; n = 21) following the completion of a psychoeducation programme in euthymic adults with BD. The primary outcome was the percentage of adherent patients (i.e., patients with a Medication Adherence Rating Scale, MARS, total score >7) at 4 months after the end of the psychoeducation programme. We also measured the changes in therapeutic adherence and beliefs on pharmacological treatments (Drug Attitude Inventory, DAI) between study inclusion and the 1-month (end of BIPOLIFE® use) and 4-month visits, healthcare use during the study period, and BIPOLIFE® acceptability.

RESULTS

The percentage of adherent patients was lower in the BIPOLIFE® group than in the TAU group at inclusion (p = 0.02). Conversely, the absolute variation of the MARS and DAI scores was higher in the BIPOLIFE® than in the TAU group at the 1-month visit (p = 0.03 and p = 0.002, respectively) but not at the 4-month visit (p = 0.22 and p = 0.07, respectively).

LIMITATIONS

Small sample size, and low frequency of connexion to BIPOLIFE® declared by the patients.

CONCLUSION

BIPOLIFE® may help patients with BD to increase their confidence in medications, if used regularly.

Dexamethasone Suppression Test May Predict More Severe/Violent Suicidal Behavior

INTRODUCTION

Several studies demonstrated that the hypothalamic-pituitary-adrenal (HPA) axis is dysregulated in suicide attempters. Prospective studies found that people with an abnormal response at the dexamethasone suppression test (DST) are more likely to commit suicide. However, whether DST may predict suicide attempts remains less clear. A possible strategy to address this question is to consider the suicide attempt lethality.

OBJECTIVES

(1) To compare the pre- and post-DST cortisol levels in serious/violent suicide attempters and in non-serious/non-violent suicide attempters, and (2) to investigate whether cortisol level can predict new suicide attempts or their lethality.

METHODS

The study included 70 recent suicide attempters (25 with a serious or violent attempt) who were followed for two years. Three saliva samples for cortisol measurement were obtained at 8a.m., 3p.m., and 9p.m. before the DST (pre-DST). Then, at 11 p.m., 1 mg of dexamethasone was given orally. The following day (post-DST), three saliva samples were collected at the same hours as before. The post-DST-pre-DST salivary cortisol Δ index was calculated for each collection time. The Risk-Rescue Ratio Scale (RRRS) and the Suicidal Intent Scale (SIS) were used to characterize the suicide attempt at inclusion and those occurring during the follow-up.

RESULTS

Post-DST cortisol level at 9 p.m. was higher in patients with an initial violent or serious suicide attempt than in non-violent/non-serious attempters (p < .010). Higher post-DST cortisol at 9p.m. was associated with lower RRRS rescue score and higher clinical impression of suicide severity at inclusion. Among the 66 patients who completed the follow-up, 26 attempted suicide again at least once. Higher pre-DST cortisol at 8a.m. predicted new suicide attempts during the follow-up (OR = 2.15 [1.11, 4.15]), and higher cortisol Δ index at 9p.m. was associated with higher suicide intent during the follow-up.

CONCLUSIONS

Our results suggest that HPA axis hyper-reactivity monitored with the DST is a marker of violent/serious suicide attempt with lower rescue possibility. Furthermore, higher changes between pre-DST and post-DST cortisol levels may predict higher suicide intent. These findings might help to characterize the biological features of nearest suicide phenotypes.

Thermodynamic signatures of quantum criticality in cuprate superconductors

The three central phenomena of cuprate (copper oxide) superconductors are linked by a common doping level p*-at which the enigmatic pseudogap phase ends and the resistivity exhibits an anomalous linear dependence on temperature, and around which the superconducting phase forms a dome-shaped area in the phase diagram¹. However, the fundamental nature of p* remains unclear, in particular regarding whether it marks a true quantum phase transition. Here we measure the specific heat C of the cuprates Eu-LSCO and Nd-LSCO at low temperature in magnetic fields large enough to suppress superconductivity, over a wide doping range² that includes p*. As a function of doping, we find that C_el/T is strongly peaked at p* (where C_el is the electronic contribution to C) and exhibits a log(1/T) dependence as temperature T tends to zero. These are the classic thermodynamic signatures of a quantum critical point^3-5, as observed in heavy-fermion⁶ and iron-based⁷ superconductors at the point where their antiferromagnetic phase comes to an end. We conclude that the pseudogap phase of cuprates ends at a quantum critical point, the associated fluctuations of which are probably involved in d-wave pairing and the anomalous scattering of charge carriers.

Binge eating behaviours in bipolar disorders

BACKGROUND

Recent research, especially from the USA, suggests that comorbid binge eating (BE) behaviour and BE disorder are frequent in individuals with Bipolar Disorder (BD). Although basic clinical associations between BD and BE have been investigated, less is known about psychological or temperamental dimensions and qualitative aspects of eating habits. In a French cohort of patients with BD, we investigated the prevalence of BE behaviour and any associations with illness characteristics, anxiety, impulsivity, emotional regulation and eating habits.

METHODS

145 outpatients with BD (I and II) were assessed for the presence of BE behaviour using the Binge Eating Scale (BES). Characteristics identified in univariate analyses as differentiating BD cases with and without BE behaviour were then included in a backward stepwise logistic regression (BSLR) model.

RESULTS

In this sample, 18.6% of BD patients met criteria for BE behaviour. Multivariate analysis (BSLR) indicated that shorter duration of BD, and higher levels of anxiety and emotional reactivity were observed in BD with compared to BD without BE behaviour.

LIMITATIONS

Relatively small sample referred to specialist BD clinics and cross-sectional evaluation meant that it was not possible to differentiate between state and trait levels of impulsivity, emotional instability and disinhibition. These dimensions may also overlap with mood symptoms.

CONCLUSION

BE behaviour is common in females and males with BD. Emotional dysregulation and anxiety may represent important shared vulnerability factors for worse outcome of BD and increased likelihood of BE behaviour.

Une expérience d’équipe mobile en psychiatrie générale

L’Équipe Mobile d’Argelès Psychiatrique (EMAP) a vu le jour le 1er septembre 2011. Elle a été financée dans un cadre expérimental, par l’Agence Régionale de Santé du Languedoc-Roussillon. Le projet s’inscrivait dans les travaux du Conseil Local de Santé Mentale (CLSM) d’Argelès-sur-Mer (66700). Il faisait suite à plusieurs constats. Pour de multiples raisons, et notamment du fait de l’augmentation considérable des soins ambulatoires, le nombre des visites à domicile a régulièrement diminué ces dernières années et s’est progressivement recentré sur le suivi de patients connus. D’autre part, il existe un nombre d’hospitalisation d’office historiquement bien plus élevé dans les Pyrénées Orientales que la moyenne nationale (88 hospitalisations d’office pour 100 000 habitants âgés de 20 ans et plus dans les PO contre 25 pour 100 000 habitants au niveau national en 2007. Ce nombre était de 83 pour notre secteur géographique). Les représentants des usagers et des familles étaient très en demande d’interventions rapides dans la communauté. Cette attente faisait écho à celle d’un grand nombre des partenaires du réseau sanitaire (médecins généralistes) mais également social ou médicosocial pour évaluer certaines situations orientées par défaut vers le service des urgences psychiatriques au centre hospitalier de Perpignan. Malgré les efforts de communication et d’information entrepris de longue date, il était noté, dans la pratique quotidienne, l’insuffisance des liens avec les services municipaux, la police, la gendarmerie, les pompiers et parfois les services sociaux pour prévenir les situations de crise. Enfin, l’existence d’une Équipe Mobile Psychiatrie Précarité rattachée au service depuis une quinzaine d’années permettait de s’appuyer sur une expérience déjà solide. Par opposition à notre EMPP qui est intersectorielle, l’EMAP s’est inscrite d’emblée dans une dimension sectorielle, rattachée à part entière à un CMP desservant un territoire de 40 000 habitants. Il s’agit d’une équipe rapidement mobilisable, à la demande des patients, des familles ou des différents partenaires du champ médical, social et judiciaire pour anticiper et évaluer les situations de crise de nature psychiatrique. Au-delà de l’évaluation, elle organise, si besoin, les soins de la manière la plus adaptée. Cette équipe spécialisée, pluridisciplinaire, va :

– développer les relations de réseau entre des acteurs pouvant recevoir les mêmes publics mais se connaissant peu ;

– intervenir sur signalement pour évaluer les situations de crise susceptibles de relever de réponses psychiatriques ou, ce qui est préférable, pouvant les anticiper.

L’expérience des deux premières années de fonctionnement permet de retenir un bilan intéressant, notamment la diminution très sensible des hospitalisations en SDRE sur l’aire géographique desservie et une complémentarité naturelle avec l’activité de CMP classique. Ce bilan sera détaillé dans cette publication.

Methadone and EDDP in hair from human subjects following a maintenance program: results of a pilot study

A specific method has been developed for the quantitative determination of methadone (MTD) and its major metabolite, 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP), in hair.An amount of 50mg hair samples were incubated in 0.01M HCl overnight at 60 degrees C and deuterated internal standards of MTD and EDDP were added before extraction. Hydrolyzed solutions were extracted by automated solid-phase extraction procedure and analyzed on a gas chromatography (GC) coupled to a ion trap mass spectrometer (MS). Positive chemical ionization was used with acetonitrile as liquid reagent. The different validation parameters, linearity, repeatability, recovery and detection limits are presented. A relative standard deviation (R.S.D.) of 12 and 11% was obtained for the repeatability of MTD and EDDP, respectively. The limits of quantification (LOQ) was 0.05ng/mg for MTD and 0.2ng/mg for EDDP.A number of 26 hair samples from human subjects following a long-term MTD therapy were analyzed by this method. Blood samples of these subjects were analyzed with a routine method using a liquid-liquid extraction and GC/nitrogen phosphorus detector (NPD). MTD was quantified in blood and hair samples and EDDP found in 50% of the hair sample.A comparison was made between the concentrations found in blood or in hair and the dose administrated. This study could demonstrate that there is no relation between the administrated dose and MTD or EDDP concentrations in hair.

Acetylcodeine as a marker of illicit heroin in human hair: method validation and results of a pilot study

Acetylcodeine (AC), which is an impurity of illicit heroin synthesis, was suggested as a marker of heroin abuse. A procedure for simultaneous quantitation of 6-monoacetylmorphine (6-MAM), which is the major metabolite of heroin, morphine, codeine, and AC in hair was developed. Fifty-milligram hair samples were incubated in 0.01 M HCl overnight at 60 degrees C. The resulting hydrolyzed solutions were extracted by an automated solid-phase extraction procedure and drugs were analyzed by gas chromatography-mass spectrometry in selected ion monitoring mode (SIM). This required prior derivatization with propionic anhydride. Different validation parameters, such as linearity, intra-assay accuracy, extraction recoveries, and limit of quantitation, were described. Seventy-three hair samples from heroin abusers and 43 hair samples from subjects who had completed a heroin-maintenance program were analyzed. AC was detected in 92% of the first sample group and in only 12% of the second sample group. In the two groups, about 98% of AC-positive samples were found. These results prove that AC can be considered as a suitable marker of illicit heroin use, along with 6-MAM detection.

Analysis of drugs of abuse in hair by automated solid-phase extraction, GC/EI/MS and GC ion trap/CI/MS

In our laboratory, analysis of human hair for the detection of drugs of abuse was first performed in 1995. Initially, requests for hair analysis were few, and it is only since 1997 that these analyses have become routine. As demand grew, we developed an automatic solid-phase extraction method; the use of a robot ASPEC allowed us to drop certain fastidious manipulations, and to treat a large number of samples at a time. This method is described, along with analysis by gas-chromatography-mass spectrometry (GC/MS) in selected ion monitoring mode (SIM), for the following drugs: codeine, 6-monoacetylmorphine (6-MAM), morphine, cocaine, methadone, ecstasy (MDMA) and Eve (MDE). This requires prior derivatization with propionic anhydride. The different validation parameters, linearity, repeatability, recovery and detection limits are described, as well as the application of this method to some real cases. Analysis of these cases is also performed by an ion trap GC/MS in chemical ionization mode (GC/IT/CI/MS) in order to demonstrate the usefulness of this technique as a complement to routine analysis. Analysis by GC/IT/CI/MS indeed avoids the risk of false-positive results by the identification of metabolites.

Analysis of methaqualone in biological matrices by micellar electrokinetic capillary chromatography. Comparison with gas chromatography-mass spectrometry

The analysis of methaqualone (MTQ) in biological matrices by capillary electrophoresis (CE) is described. This methods uses liquid-liquid extraction and micellar electrokinetic capillary chromatography (MECC), an operation mode of CE. Separations are made using a 25 cm long capillary and a borate/phosphate buffer at pH 8.2. Using gas chromatography with mass spectrometry detection (GC-MS) as reference method, MTQ has been analyzed in urine, blood, gastric content and hair. For hair analysis, supercritical fluid extraction was compared with liquid-liquid extraction. Linearity was established in urine and blood between 0.25 and 10.0 micrograms/ml. MTQ recovery from blood was estimated at 60%. The limit of detection of this method in urine is about 0.10 microgram/ml. Drawbacks and advantages of MECC over GC-MS are discussed.

Mapping of corticotropic cells in the normal human pituitary

We accomplished the first mapping of corticotropic cells in the whole human adult pituitary. Corticotropic cells were identified by immunocytochemistry (ICC) and quantified by image analysis on 12 pituitaries obtained from people who had died suddenly. An overall view of each pituitary was given by 15-21 sections (mean 18 sections) at 300-micron intervals on six slides. Each section was systematically treated by indirect immunoperoxidase using an anti-ACTH[17-39] polyclonal antiserum. All the measures were done with a x 6.3 objective lens, each field (0. 5 mm2) being considered as the unit area. The mean pituitary density (surface of labeled cells/total surface) of corticotropic cells (9.5 +/- 3.0% per 0. 5 mm2) is significantly higher in men (11.5 +/- 5.1%) than in women (7.0 +/- 1.3%). This difference is due to an inverse relationship between the corticotropic cell density and the weight of the pituitary, which is higher in women than in men. The mean diameter of corticotropic cells is 14.9 micron and their total number per pituitary is approximately 10(7) cells. We confirmed that the spatial distribution of corticotropic cells is nonuniform: they are mainly distributed in the anteromedian part of the anterior lobe. In addition, our results demonstrated that the inferior part of the pituitary contained three times more corticotropic cells than the superior part (mean density 18.0% vs 6.0%) and the anterior part twice as many as the posterior part (mean density 12.3% vs 6.8%). On the horizontal plane, the pituitary was divided into eight zones, in which the mean of area was 2.5-21.0%. The maximal cell density may reach 40-60%. The use of this map should help the pathologist to recognize if there is corticotropic hyperplasia in a small pituitary fragment surgically removed from a patient with Cushing's disease. On the basis of this study, we put forward some criteria for diagnosing corticotropic hyperplasia.

Effects of aluminum on bone surface ion composition

Aluminum induces net calcium efflux from cultured bone. To determine whether aluminum alters the bone surface ion composition in a manner consistent with predominantly cell-mediated resorption, a combination of cell-mediated resorption and physicochemical dissolution or physicochemical dissolution alone, we utilized an analytic high-resolution scanning ion microprobe with secondary ion mass spectroscopy to determine the effects of aluminum on bone surface ion composition. We cultured neonatal mouse calvariae with or without aluminum (10(-7) M) for 24 h and determined the relative ion concentrations of 23Na, 27Al, 39K, and 40Ca on the bone surface and eroded subsurface. Control calvariae have a surface (depth approximately 6 nm) that is rich in Na and K compared with Ca(Na/Ca) = 24.4 + 1.4, mean + 95% confidence limit of counts per second of detected secondary ions, K+Ca = 13.2 + 0.9). Aluminum is incorporated into the bone and causes a depletion of surface Na and K relative to Ca (Na/Ca = 9.6 + 0.7, K/Ca = 4.9 + 0.4; each p < 0.001 versus control). After erosion (depth approximately 50 nm), control calvariae have more Na and K than Ca (Na/Ca = 16.0 + 0.1, K/Ca = 7.5 + 0.1); aluminum again depleted Na and K relative to Ca (Na/Ca = 4.1 + 0.1 K/Ca = 1.9 + 0.1; each p < 0.001 versus control). Aluminum produced a greater net efflux of Ca (362 +/- 53, mean +/- SE, nmol/bone/24 h) than control (60 +/- 30, p < 0.001). With aluminum, the fall in the ratios of both Na/Ca and K/Ca coupled with net Ca release from bone indicates that aluminium induces a greater efflux of Na and K than Ca from the bone surface and is consistent with an aluminum-induced removal of the bone surface. This alteration in surface ion concentration and calcium efflux is consistent with that observed when calcium is lost from bone through a combination of cell-mediated resorption and physicochemical dissolution.

Prenatal and postpartum Pap smears: do we need both?

PURPOSE

The need to perform a Pap smear at the time of entry to prenatal care, as well as at the postpartum check-up, is questionable. A comparison of the rates of recovery of endocervical cells and the incidence of dysplasia on the prenatal and postpartum Pap smears may be helpful in determining an optimal preventive care protocol for patients who are pregnant.

METHODS

Demographic and clinical data were collected from the records of 1,377 obstetrical patients at a midwest family practice residency. The yield of endocervical cells and the incidence of dysplasia was determined for both the prenatal and the postpartum Pap smears performed for this group of patients.

RESULTS

In women having both exams, endocervical cells were recovered in 44.1% of prenatal Pap smears compared to 82.0% of postpartum smears. The incidence of dysplasia was 2.6% on prenatal Pap smears and 4.8% on postpartum smears. In this study population, 33% of women did not return for their postpartum check-up.

CONCLUSIONS

The postpartum Pap smear is of value due to a significant yield of dysplasia. The sensitivity of the prenatal Pap test may be less than desired. Efforts directed toward increased patient compliance regarding the postpartum check-up are needed.

Inhibitory effects of the dopamine agonists quinagolide (CV 205-502) and bromocriptine on prolactin secretion and growth of SMtTW pituitary tumors in the rat

The SMtTW tumor, a spontaneous PRL-secreting transplantable tumor, is the only available animal model sensitive to dopamine agonists. This model has been used to compare the long term in vivo effects of CV 205-502 (CV) and bromocriptine (BR) on PRL secretion and tumor growth. These two drugs were given for 2 months to female Wistar-Furth rats bearing either small or large tumors 4 and 6 months after the graft. Untreated grafted rats served as control. In all rats treated with 5 or 10 mg/kg.day BR or 0.3 mg/kg.day CV, a normalization of plasma PRL levels was observed whatever the pretreatment levels (plasma PRL or CV or BR-treated rats, < 15 ng/ml vs. 28253 ng/ml in control rats 8 months after graft). An inhibition of tumor growth was found for both small and large tumors, but the tumors never disappeared completely (mean tumor weights at autopsy, 440 and 660 mg in BR and CV groups vs. 5270 mg in control group 8 months after graft). Experiments performed with increasing doses of BR (0.15-5 mg/kg.day) or CV (0.03-0.6 mg/kg.day) indicated that CV is effective at doses 5-10 times lower than those of BR. A shrinkage under treatment and a regrowth after drug withdrawal were demonstrated for large tumors by in vivo ultrasonographic measurements of tumor size. Histological and ultrastructural effects were similar for the two drugs: decrease in hemorrhage, reduction of the cell size and secretory activity, increase in immunoreactive PRL cellular content, and inhibition of exocytosis. There was no difference in the PRL mRNA content of treated and untreated tumors, as assessed by in situ hybridization. In conclusion, CV and BR exhibit similar inhibitory effects on tumor growth and PRL secretion. These effects are rapidly and fully reversible after drug withdrawal. The present results give a complete account of the actions of the two dopamine agonists under conditions comparable to those used in the treatment of human prolactinomas.

Fetal Niemann-Pick disease type C: ultrastructural and lipid findings in liver and spleen

We present the first ultrastructural study of liver and spleen from a 20-week fetus with Niemann-Pick disease type C in correlation with lipid studies of these tissues. The lipid storage pattern was characteristic of the disease and although the distribution of the lipid storage was similar to that of affected children, ultrastructural studies emphasized that many inclusions were qualitatively different. These are discussed. Concomitant with this complex lipid storage, ultrastructural evidence of cholestasis was observed and the early hyperplasia of pericanalicular microfilaments leads us to question the presence of a toxic metabolite which might induce cholestasis by acting upon microfilaments.

Farber disease: an ultrastructural study. Report of a case and review of the literature

A case of Farber disease is reported and the ultrastructural pathology of the disease is reviewed. The present case showed the typical clinical picture of Farber disease. Acid ceramidase deficiency was demonstrated biochemically. Ultrastructural features of one subcutaneous nodule and a skin biopsy are described. Three lysosomal inclusions characterize Farber disease: curvilinear tubular bodies observed mainly in the reticuloendothelial system, "banana bodies" recorded only in the peripheral nervous system and zebra-like bodies which are essentially a neuronal storage. The nature of each is discussed and the skin biopsy is emphasized for its important diagnostic interest.

Somatotropic adenomas without acromegaly

Seventeen somatotropic adenomas removed from patients without acromegaly were studied. Thirteen of them presented as a prolactinoma with amenorrhea and/or galactorrhea and elevated serum PRL levels. According to basal serum GH levels, the patients were divided into two groups, namely Group I: GH slightly elevated (n = 4) and group II: GH less than or equal to 5 micrograms/l (n = 13). The tumoral GH secretion was proved by immunocytochemistry in all cases and by intratumoral RIA, in vitro study and/or in situ hybridization in five of them. Pathological, clinical and biochemical relationships suggested two anatomoclinical aspects. In group I, the tumors were small, well-differentiated somatotropic adenomas with clinically silent GH hypersecretion. It is probably an early stage of the disease. In group II, the tumors were large with normal GH serum levels. They were poorly differentiated and secreted very low amounts of GH. In nine of them, PRL and/or PRL mRNA expression were also detected. These tumors do not secrete enough GH to increase serum levels and cause acromegaly. The somatotropic adenomas without acromegaly correspond to two anatomoclinical aspects of the disease.

Variability of hemodynamic values and plasma catecholamine concentrations over a one-hour period in conscious, restrained rats

Restrained conscious rats have been widely used for physiological and pharmacological hemodynamic studies. In this condition, the variability of the circulation is unclear. Repeated measurements in restrained normal rats showed stable systemic hemodynamics (cardiac output ranging from 130 +/- 14 to 174 +/- 10 mL/min, mean arterial pressure ranging from 109 +/- 9 to 117 +/- 5 mmHg) and splanchnic hemodynamics (splanchnic blood flow ranging from 8.51 +/- 1.89 to 13.01 +/- 1.45 mL min-1 100 g-1 body wt) over a period of 1 hr. Slight but not significant hemodynamic variations, however, occurred in pulmonary blood flow. Similarly, plasma noradrenaline concentrations did not vary over this period (plasma noradrenaline level ranging from 186 +/- 36 to 358 +/- 64 pg/mL). These plasma noradrenaline concentrations were similar to those measured in a group of conscious unrestrained rats 3 hr after recovery from surgery (292 +/- 60 pg/mL). A significant correlation was observed between plasma noradrenaline concentration and heart rate.

Divergent circulatory effects of betaxolol in conscious and anesthetized normal and portal hypertensive rats

We aimed to define the circulatory effects of beta 1-blockade in conscious normal and portal hypertensive rats and determine if pentobarbital anesthesia affected these responses. A selective beta 1-antagonist, betaxolol, was given to four groups: conscious and anesthetized sham-operated and portal hypertensive rats. Cardiac output and splanchnic organ blood flows were measured by radioactive microspheres twice in each rat, before and 15 min after betaxolol. Both groups of conscious rats maintained mean arterial pressure despite significant decreases in cardiac output and heart rate, by increasing total peripheral resistance. Anesthetized rats were unable to do this and thus also diminished arterial pressure significantly, with portal hypertensive rats showing greater decreases than sham-operated rats. Portal tributary flow and portal pressure decreased only in the anesthetized rats. Autoregulation of splanchnic blood flow was not uniform between groups or organs: although splenic flow decreased in all four groups, intestinal blood flow decreased only in anesthetized portal hypertensive rats. The greatest decreases in several splanchnic organ blood flows were seen in this latter group. These results indicate that: (i) pentobarbital markedly changes systemic and splanchnic responses to beta 1-blockade; (ii) splanchnic autoregulation is not uniform--the intestinal circulation enjoys more protection than the splenic; and (iii) portal hypertensive rats seem to be more vulnerable to the circulatory effects of beta 1-blockade.

Scanning ion microprobe assessment of biological sample preparation techniques

Different preparation techniques for high lateral resolution scanning ion microprobe imaging of biological samples have been investigated. The sharpest histological maps are obtained from chemically fixed and plastic embedded specimens. It is often problematic to correlate ultrastructure and bioaccumulation from analysis of frozen cut and lyophilized sections. The best compromise is to resin-embed frozen samples in order to get a perfectly flat section from tissue where the in vivo ion distribution is maintained. Use of the University of Chicago Ion Microprobe gave us the ability to observe the relative ion translocations induced during sample preparation. As an example, we show the rapid decrease of intracellular K+/Na+ ratio through a fast frozen blood droplet.

Spontaneous prolactin transplantable tumor in the Wistar/Furth rat (SMtTW): a new animal model of human prolactinoma

Two spontaneous prolactinomas, removed from 28-mo-old female Wistar/Furth rats, were grafted by serial passages under the kidney capsule and the skin in 117 females of the same consanguineous strain. The hosts, aged between 2 and 10 mo, were free of estrogen treatment. These transplantable tumors, named SMtTW1 and SMtTW2, were studied until the fifth serial passage. The percentage of success was 100% under the kidney capsule and 20% under the skin. From the radioimmunoassays of prolactin (PRL), growth hormone, and adrenocorticotropic hormone and the immunocytochemical results, the tumors secrete PRL only. The PRL tumoral secretion was detected after 3 to 5 mo of graft; at 8 mo, mean plasma PRL values reached 5150 ng/ml (normal value, 15.2 ng/ml). Plasma growth hormone and adrenocorticotropic hormone values remained normal. Like the primary tumors, the grafted tumors were benign, grew slowly, and were sparsely granulated well-differentiated prolactinomas with exocytosis. They remained identical during the first serial passages. The secretion and the growth of SMtTW2 were inhibited by bromocriptine. In the light of our knowledge of the human prolactinoma, the spontaneous transplantable prolactinoma of the rat may be considered to be an animal model closer to the human pathology than the estrogen-induced "tumors" and the induced transplantable tumors. It is easier to use than the spontaneous prolactinoma of the rat.

Human epithelial thymic tumours: heterogeneity in immunostaining of epithelial cell markers and thymic hormones

Different hormones (thymulin, thymosin alpha 1, vasopressin), antigenic markers of cortical and subcapsular/medullary thymic areas and tumour associated antigens were studied on paraffin or frozen section and cultures of human epithelial thymic tumours ('thymomas'). Thymulin, thymosin alpha 1 and for the first time vasopressin are found in most tumours. The epithelial cells of five 'thymomas' had markers of both cortical (TE3) and subcapsular/medullary thymic regions (A2B5 and/or TE4 and/or anti-p19). Leu-7, a marker of subcapsular epithelial cells was positive only in two tumours. The histological classification into cortical and medullary tumours does not correspond to our immunofluorescence results. The presence of these markers does not support the theory of different embryologic origin of the cortical and subcapsular/medullary epithelial cells. Transferrin receptors were detected on only some epithelial cells of thymic 'carcinomas'. Adenocarcinoma related antigen and carcino embryonic antigen only stained a few epithelial cells of all the tumours. There is no expected correlation between the presence of epidermal growth factor receptors on cell membranes and the number of proliferative cells stained by the anti-Ki67 antibodies. Immunostainings were heterogeneous according to the epithelial thymic tumours, independent of histological classification and not yet useful for prognosis.

Effects of haemorrhage and volume expansion on portal-systemic collateral vascular resistance in conscious portal hypertensive rats

1. In order to study the acute effects of blood volume changes on the vascular resistance of portal-systemic collaterals (collateral vascular resistance), a model of total portal vein occlusion with 100% portal-systemic shunts was developed in the rat. In this model, we determined the haemodynamic effects of haemorrhage (1.8 ml/100 g body weight) or intravenous infusion of a volume expander (1.8 ml/100 g body weight). Cardiac output and regional blood flows were measured by the radioactive microsphere method. 2. Haemorrhage significantly reduced arterial pressure from 108 +/- 4 to 92 +/- 4 mmHg (mean +/- SEM), cardiac output from 56 +/- 4 to 24 +/- 2 ml min-1 100 g-1 body weight, portal pressure from 15.1 +/- 1.5 to 10.0 +/- 1.4 mmHg and portal tributary blood flow from 19.9 +/- 2.3 to 8.3 +/- 1.4 ml/min. Consequently, collateral vascular resistance significantly increased from 6.6 +/- 0.9 x 10(3) to 11.1 +/- 2.0 x 10(3) kPa 1(-1) s. 3. Volume expansion reduced arterial pressure from 98 +/- 3 to 90 +/- 3 mmHg, and significantly increased cardiac output from 43 +/- 3 to 55 +/- 3 ml min-1 100 g-1 body weight, portal pressure from 13.9 +/- 0.7 to 16.5 +/- 0.8 mmHg and portal tributary blood flow from 16.4 +/- 1.3 to 28.2 +/- 3.2 ml/min. Consequently, collateral vascular resistance significantly decreased from 7.0 +/- 0.5 x 10(3) to 4.9 +/- 0.4 x 10(3) kPa l-1 s. 4. This study shows that in rats with portal hypertension, portal-systemic collateral vascular resistance is modified by alterations in blood volume.

Mesenteric venous stenosis reduces hyperammonemia in the portacaval-shunted rat

Hyperammonemia is a constant finding following portacaval anastomosis (PCA), and has been incriminated in the neurologic deterioration observed following portasystemic shunt in humans. We developed a rat model for mesenteric venous hypertension by modification of a commonly used technique for studying extrahepatic portal hypertension. We then examined serum ammonia levels in rats undergoing sham operation, mesenteric vein stenosis (MVS) alone, PCA alone, and MVS plus PCA. All MVS animals had a significant (p less than 0.05) elevation in mesenteric venous pressures 2-3 weeks after operation. Serum ammonia levels were normal in rats undergoing sham operation and MVS, and were significantly elevated (p less than 0.001) in rats with PCA. However, a significant (p less than 0.01) reduction in serum ammonia levels was realized when PCA and MVS were combined. These data suggest that intestinal ammonia absorption is a function of splanchnic venous pressure. These findings may be relevant to the management of the neuropsychiatric deterioration seen following PCA in man.

Mechanisms of a clonidine-induced decrease in portal pressure in normal and cirrhotic conscious rats

The effects of clonidine on portal pressure and splanchnic blood flow were studied in conscious rats with sinusoidal portal hypertension due to cirrhosis induced by bile duct ligation. In cirrhotic and sham-operated rats, clonidine (20 micrograms per kg body weight, intravenously) significantly reduced portal, pressure from 19.0 +/- 0.6 to 14.5 +/- 1.0 mmHg and from 9.8 +/- 0.9 to 7.3 +/- 0.5 mmHg, respectively. No significant change in systemic hemodynamics was observed. In cirrhotic rats, clonidine reduced portal pressure, probably by producing a significant increase in portal tributary vascular resistance leading to a 25% decrease in portal tributary blood flow (radioactive microsphere method). In sham-operated rats, clonidine reduced portal pressure presumably by decreasing hepatic portal vascular resistance, since no significant change in portal tributary blood flow was observed. In both groups, clonidine administration significantly decreased plasma noradrenaline concentration. Placebo administration produced neither significant hemodynamic nor significant plasma noradrenaline concentration change. These findings indicate that the sympathetic regulation of the splanchnic circulation is impaired in cirrhotic rats.

Discrepancy between portal pressure and systemic hemodynamic changes after incremental doses of propranolol in awake portal hypertensive rats

The effects of increasing doses of propranolol were studied in awake portal hypertensive rats in order to elucidate the relative effects of the beta-blocker on systemic and splanchnic circulation. Hemodynamic responses to 0.1, 0.2 and 0.4 mg per min infusions of propranolol were compared with placebo in awake rats with portal hypertension due to portal vein stenosis. Heart rate significantly and progressively decreased from 356 +/- 13 to 293 +/- 10 beats per min (mean +/- S.E.). Cardiac output significantly decreased from 54 +/- 3 to 42 +/- 3 ml per min per 100 gm body weight at the highest dose. Significant decrease in portal tributary blood flow from 27 +/- 1 to 18 +/- 1 ml per min, at 0.4 mg per min dose, was due not only to the decrease in cardiac output but also to a significant increase in portal tributary vascular resistance from 269 +/- 17 to 368 +/- 31 dyne per sec per cm5 x 10(3). However, portal pressure showed only an insignificant decrease from 14.9 +/- 1.1 to 14.1 +/- 1.4 mmHg. The reduction in portal pressure being minimal, in spite of a significant decrease in portal tributary blood flow, is explained by an increase in combined hepatic and collateral resistance from 44 +/- 2 to 66 +/- 4 dyne per sec per cm5 x 10(3), p less than 0.05, at 0.4 mg per min dose. We conclude that the systemic and splanchnic effects of propranolol show discrepancy at two levels.(ABSTRACT TRUNCATED AT 250 WORDS)

Inversely related evolution of growth hormone and prolactin secretions in long-term tissue cultures of human pituitary adenomas from acromegalic patients

Pituitary tumoral tissue from 20 acromegalic patients was cultured for up to 120 d in a medium containing 5 nM cortisol. In all cultures, growth hormone (GH) release decreased. At the beginning of the culture, prolactin (PRL) was detected in 18 adenomas, varying from 0.5 to 1000 ng per flask per day. Thereafter, in 10 cases PRL secretion increased from 3 to 50 times the basal level, most frequently after a lapse of 9 to 30 d. PRL secretion remained low in three cases, undetectable in one case only. When added at 350 nM, cortisol increased GH secretion up to 20-fold and simultaneously decreased PRL secretion by as much as 10% of the basal level. Withdrawing cortisol reversed the situation. Immunocytochemical studies of the tumor at surgery showed, besides GH immunoreactive (IR) cells, PRL-IR cells (from rare cells to 10% of total cells) in 15 adenomas, correlating with the first days of culture PRL levels. In cultured explants, mitoses were never found. In 5 nM cortisol medium, the number of GH-IR cells decreased and PRL-IR cells increased or appeared. With 350 nM cortisol, the number of GH-IR cells increased, and PRL-IR cells were scarce or absent. Immunoreactivities for GH and PRL were found in different cells. Care was taken to exclude cultures containing normal pituitary tissue, and because no mitoses were found, these results suggest that most somatotropic adenomas can reversibly shift their secretion from GH to PRL in culture. This capacity to secrete PRL, hidden or low in vivo, is revealed by the favorable low cortisol conditions present in vitro.

Model for the study of portal-systemic collateral vascular resistance in the conscious rat

In order to obtain a model for the study of portal-systemic collateral vascular resistance, total portal vein occlusion was performed in rats 48 hr or 3 wk after partial obstruction. Four groups of conscious restrained rats were studied: a) sham-operated, b) partial portal vein ligated, c) 48 hr-total portal vein occluded, and d) 3 wk-total portal vein occluded. In comparison with the sham group, the three portal vein ligated groups had significantly higher cardiac output, portal tributary blood flow, portal pressure (7.7 +/- 0.4 versus 13.5 +/- 0.5, 13.6 +/- 0.8, and 17.7 +/- 1.1 mmHg, mean +/- SE, respectively) and hepatic arterial blood flow (5.8 +/- 0.6 versus 9.5 +/- 0.7, 8.3 +/- 0.5, and 13.9 +/- 1.9 ml/min, respectively). Cardiac output and portal tributary blood flow did not differ between the portal vein ligated groups, but portal pressure and hepatic arterial blood flow were significantly higher in the 3 wk-total portal vein occlusion group. The 3 wk-total portal vein occlusion group showed 99.1 +/- 0.3% shunting, different from the partial (29.7 +/- 16.9%, p less than 0.01) and 48 hr-total portal vein occlusion (46.5 +/- 14.7%, p less than 0.05) groups. Portography confirmed absence of portal-portal collaterals in the 3 wk-total portal vein occlusion group. It is suggested that rats with 3 wk-total portal vein occlusion are useful for the study of acute modifications of portal-systemic collateral circulation, as shunting is total and consistent in this model.

Animal models of human pituitary tumors

Three animal models of pituitary tumors were compared: the spontaneous prolactinoma in Wistar/Furth (W/Fu) rats, an estrogen-induced transplantable tumor in the Fischer rat (MtTF4), and a spontaneous prolactin transplantable tumor in the W/Fu rat (SMtTW1). The spontaneous prolactinoma in W/Fu rats is interesting in that it resembles the human prolactinoma by its morphological characteristics, its benign nature, and its secretion of prolactin alone. It may be useful to study the initial factors of tumorigenesis but it is very expensive and the variability of tumor growth makes it difficult to plan experiments. The MtTF4 tumor is an easy model to study because it is transplantable but this tumor differs from most human pituitary tumors by its induction by estrogen, its malignancy, its undifferentiated aspect and its secretion of ACTH, GH, and prolactin. The SMtTW1 tumor, a new model of transplantable tumor, is close to the human pituitary tumor because the initial tumor is spontaneous, the transplanted tumors are benign and well differentiated. They secrete prolactin only. These transplantable tumors are valuable for studying the factors of growth. Since no single tumor system is a perfect model, researchers have to work on different models each of which is appropriate for investigating specific problems.

The TSH secretion in the human pituitary adenomas

TSH secretion by a pituitary tumor is very rare (2%) and it is often associated with another hormone: GH or PRL essentially. We present here nine tumors in which the TSH secretion was proved by immunocytochemistry (ICC) and by RIA in the tumor extracts, in the serum and in the culture medium. Four tumors secreted TSH only. Five tumors secreted TSH and GH predominantly. In 3 of them traces of other hormones (PRL and FSH) were also detected. The "pure" TSH adenomas were monomorphous with typical ultrastructural and immunocytochemical features. Plurihormonal TSH adenomas were bimorphous with different cells secreting GH and TSH or monomorphous with one type of cell which secreted TSH or GH or both TSH and GH. In a majority of the cases, the tumoral TSH secretion induced hyperthyroidism but in 2 patients with TSH adenoma there was euthyroidism and in another with TSH-GH adenoma there was no sign of acromegaly and GH serum levels were normal.

[Effect of the development of portosystemic shunts in the maintenance of portal hypertension in rats]

We studied the role of portosystemic shunt development in the maintenance of portal hypertension in a prehepatic portal hypertension rat model. A first group was studied two days after partial portal vein ligation. When portosystemic shunts were negligible; the second group was studied 3 weeks after the partial portal vein ligation, when large portosystemic shunts were present. Portal pressure was significantly higher in the first group than in the second group (19.9 +/- 0.8 mmHg (mean +/- 1 SD) and 12.8 +/- 2.3 mmHg, respectively; p less than 0.001). When compared with sham operated rats: a) portal tributary blood flow (measured with the radioactive microspheres method) was decreased in the first group (- 34 p. 100; p less than 0.01) and increased in the second group (+ 32 p. 100; p less than 0.02); b) portal system vascular resistance was markedly increased in the first group (+ 269 p. 100; p less than 0.001) and did not significantly change in the second group (+ 30 p. 100). These results suggest that portosystemic shunt development decreases portal pressure but not to normal value because portal tributary blood flow is increased. Moreover the increase in portal system vascular resistance and in portal tributary blood flow play different roles in the maintenance of portal hypertension depending on the stage of evolution of portal hypertension.

Regional blood flows by the microsphere method: reproducibility in portal hypertensive rats and influence of a portal vein catheter

To determine the reproducibility of splanchnic blood flow measurements by the microsphere method in rats with portal hypertension and the effects of laparotomy with portal vein cannulation, eight groups of 10 rats were studied. Cardiac output and regional blood flows were measured twice, 10 min apart, in pentobarbital anesthetized or awake, sham-operated or portal vein-ligated rats, with or without portal cannulation. Variability between the two successive measurements was not affected by portal hypertension or portal cannulation, and was not different in the splanchnic territory and in other organs. Laparotomy with portal cannulation had no significant effect in sham-operated rats. In awake portal hypertensive rats, cardiac output (53.9 +/- 3.0 vs 45.8 +/- 2.9 ml.min-1.100 g body wt-1, P less than 0.01) and splanchnic blood flow (12.31 +/- 0.72 vs 9.34 +/- 0.85 ml.min-1.100 g body wt-1, P less than 0.01) were lower in portal vein cannulated rats compared with those of non-cannulated animals. In anesthetized portal hypertensive rats blood flows were unaffected by portal cannulation, but arterial pressure (100.2 +/- 4.3 vs 119.9 +/- 3.4 mm Hg, P less than 0.01) and heart rate (366.5 +/- 10.0 vs 405.5 +/- 7.4 beats.min-1, P less than 0.01) were elevated. Anesthesia also decreased portal pressure (14.8 +/- 0.5 vs 12.0 +/- 0.4 mm Hg, P less than 0.05) in portal hypertensive rats. We conclude that the microsphere method remains reproducible in portal hypertensive rat models. Laparotomy with portal cannulation can alter systemic and splanchnic hemodynamics in portal hypertensive rats; these effects can also be changed during pentobarbital anesthesia. Regional blood flow measurements in portal hypertensive rats should be performed in animals without portal cannulation and preferably in the awake state.

Circulatory effects of somatostatin analogue in two conscious rat models of portal hypertension

A somatostatin analogue, a long-acting octapeptide (SMS 201-995), has been reported to decrease portal pressure, but the mechanism is unclear. To elucidate the effects of this drug on both systemic and splanchnic hemodynamics, it was administered in two conscious rat models of portal hypertension. The dose-response curves showed that the somatostatin analogue significantly decreased portal pressure at a lower dose in rats with cirrhosis than in portal vein-stenosed rats. Calculated ED50 values were significantly different among all groups. Intravenous infusion of 8 micrograms/kg body wt.h of somatostatin analogue significantly decreased cardiac output by approximately 20% in both groups of portal hypertensive rats and increased mean arterial pressure by 7%. Accordingly, systemic vascular resistance markedly increased, indicating vasoconstrictor effects of this drug. The somatostatin analogue also significantly decreased portal tributary blood flow by 18% in portal vein-stenosed rats and 27% in cirrhotic rats. In sham-operated rats, somatostatin analogue had no effect on the systemic or splanchnic circulation. This study shows that somatostatin analogue decreases portal pressure principally by reducing portal tributary blood flow. This reduction may be due to either a direct vasoconstrictive effect or diminution in vasoactive hormone release.

Lack of vasopressin action on splanchnic hemodynamics during bleeding: a study in conscious, portal hypertensive rats

Due to the marked effects of hemorrhage on cardiac output and splanchnic hemodynamics, the circulatory actions of vasopressin may differ during bleeding as opposed to stable conditions. We evaluated this hypothesis in conscious rats with portal hypertension due to chronic portal vein stenosis, by comparing the effects of a vasopressin infusion (0.02 IU per kg per min) to those of a control saline infusion, during and after a hypotensive hemorrhage (25 ml per kg). We also studied unbled portal hypertensive rats receiving an identical infusion of vasopressin or saline. During and after hemorrhage, vasopressin induced significant changes in systemic hemodynamics but had no effect on portal pressure, portal tributary blood flow and nonhepatic splanchnic arteriolar resistance. In unbled animals, by contrast, vasopressin decreased portal pressure and portal tributary blood flow and increased nonhepatic splanchnic arteriolar resistance. Our data further indicate that hemorrhage alone caused an early vasoconstriction in the portal tributaries and a delayed vasoconstriction in the nonsplanchnic vascular bed while vasopressin during hemorrhage induced an early and sustained vasoconstriction in the nonsplanchnic vascular bed as well as in the portal tributaries. The results show that, during and after severe bleeding, vasopressin exerts little influence on portal hemodynamics. Although these data do not allow firm conclusions concerning the therapeutic efficacy of vasopressin in bleeding esophageal varices, they demonstrate that the splanchnic actions of vasoactive substances cannot be readily extrapolated from stable conditions to hemorrhage.

Naloxone does not alter haemodynamics in cirrhosis. Studies in humans and rats

In order to test the hypothesis that endogenous opioids may mediate some of the circulatory derangements in cirrhosis, we studied the haemodynamic effects of naloxone, an opioid antagonist, in patients and in a rat model of biliary cirrhosis. In 9 patients with alcoholic cirrhosis and 5 control patients without significant liver disease, cardiac output, systemic vascular resistance, mean arterial pressure, heart rate, hepatic venous pressures and O2 content, hepatic and azygos blood flows and serum catecholamines were measured before and 30 min after naloxone 3.2 mg i.v. bolus. No significant changes were observed in either group of patients. Similarly in 16 conscious rats, 8 sham-operated and 8 with cirrhosis due to bile duct ligation, cardiac output, systemic vascular resistance, mean arterial pressure, heart rate, and splanchnic organ blood flows were measured by radioactive microspheres, before and 20 min after naloxone 1 mg/kg i.v. bolus. No significant changes were observed in either group. We failed to detect any evidence that endorphins are involved in tonic haemodynamic control in cirrhosis.

Reduction of intrahepatic vascular space in the pathogenesis of portal hypertension. In vitro and in vivo studies in the rat

To elucidate a possible role for reduction of intrahepatic vascular space in the pathogenesis of portal hypertension, we studied a partially hepatectomized rat model in vitro and in vivo. The in vitro study used livers from normal, 1/3-hepatectomized, and 2/3-hepatectomized rats, and rats with cirrhosis caused by chronic bile duct ligation, for isolated, perfused flow-pressure plotting. Resistance to perfusion increased such that significant differences were found between all groups except the last two, which showed similar resistances. The in vivo study measured splanchnic blood flow by radioactive microspheres and portal pressure in anesthetized sham-operated and 1/3- and 2/3-hepatectomized rats. Although absolute portal tributary blood flows did not change, portal flow per gram of remnant liver showed significant increases: 1.57 +/- 0.32 ml/min X g liver, 2.52 +/- 0.60 ml/min X g liver, p less than 0.01; 3.48 +/- 1.04 ml/min X g liver, p less than 0.01, respectively. Although intrahepatic resistance increased significantly only in the 2/3-hepatectomized group, portal pressures increased significantly in both groups of hepatectomized rats: normal, 7.5 +/- 1.1 mmHg; 1/3-hepatectomized, 9.4 +/- 1.1 mmHg; and 2/3-hepatectomized, 11.1 +/- 1.2 mmHg. Thus, decreased intrahepatic vascular space caused by resection and hepatocellular hypertrophy leads to portal hypertension, thereby suggesting that this reduction in space may be the pathogenic factor common to a number of different theories of portal hypertension.

Immunostaining of a cell type in the islets of Langerhans of the monkey Macaca irus by antibodies against S-100 protein

S-100 protein-immunoreactive cells were demonstrated by immunocytochemical procedures in the pancreatic islets of Langerhans in the monkey Macaca irus. By use of antibodies against human S-100 protein or bovine S-100 protein, these cells were observed in all islets in the head and tail portions of the pancreas. Immunostained cells were usually located in the center of the islets or sometimes found in a more widely distributed form, but they were never arranged in a regular concentric fashion. The number of immunoreactive cells varied from one islet to another but it was relatively limited making up only 0.75%-6.3% of all insular cells. With the use of the double-immunoenzymatic procedure for demonstration of the four main endocrine cell types (insulin-, glucagon-, somatostatin- and pancreatic polypeptide producing elements), it was possible to establish that S-100 protein-immunoreactive cells represent a distinct cell type. Antibodies against S-100 protein-stained neuroinsular complexes. The present findings speak in favor of a new cell type to be added to the large variety of S-100 protein-immunoreactive cells outside the central nervous system.

Role of portasystemic shunts in the hyperkinetic circulation of the portal hypertensive rat

We evaluated the role of portasystemic shunts in the hyperkinetic circulatory state in rats with portal hypertension. Cardiac output and regional blood flow were measured by the radioactive microsphere technique in rats with portal hypertension caused by portal vein stenosis, in rats with end-to-side portacaval shunts, and in sham-operated rats. Cardiac output was significantly higher in rats with surgical shunts than in those of the two other groups and was significantly lower in sham-operated rats compared with portal hypertensive rats. Portal tributary blood flow and hepatic arterial blood flow expressed in absolute flow as well as in percentage of cardiac output were significantly increased in rats with surgical shunts compared with other groups. These blood flows were also significantly higher in portal hypertensive rats than in sham-operated animals. A significant correlation was found between cardiac output and portal tributary blood flow in rats with portal vein stenosis and in rats with surgical shunts; this correlation was absent in sham-operated rats. This study shows that the hyperkinetic circulatory state in rats with portal hypertension and a normal liver is related to the presence of portasystemic shunts but not to portal hypertension per se.

Immunocytochemical localization of S-100 protein in stellate cells (folliculo-stellate cells) of the adenohypophysis in the monkeys Macaca irus and Cercopithecus aethiops

With the use of an antibody against bovine S-100 protein, it was possible to reveal a characteristic cell type in the pars distalis and the pars tuberalis of the monkey Macaca irus. In the adenohypophysis of Cercopithecus aethiops, labeled cells were present in the pars distalis, pars tuberalis, and pars intermedia. These cells, so-called folliculo-stellate cells, were found in all pituitaries studied. Surprisingly, an antibody against human S-100 protein did not label the stellate cells of the adenohypophysis. However, in Macaca irus, this antibody gave a strong positive reaction with various other cell types (interstitial cells of the pineal gland, Müller cells of the retina, autonomic ganglionic cells, glial cells of the central nervous system, Schwann cells, Bergmann glia of the cerebellum, fat cells, reticular cells of lymphoid organs). By use of double immunoenzymatic labeling, it was evident that stellate cells are spatially related either to somatotropes, prolactin cells, "corticotropes", or to glycoprotein-containing cells. Thus, a specific relationship to a particular endocrine-cell type could not be observed.

Hemodynamic characterization of chronic bile duct-ligated rats: effect of pentobarbital sodium

Systemic and splanchnic hemodynamics of the chronic bile duct-ligated rat were characterized by radioactive microspheres. Conscious and pentobarbital sodium-anesthetized, bile duct-ligated and sham-operated rats had cardiac output and regional organ blood flows determined. The conscious bile duct-ligated rat compared with the sham-operated showed a hyperdynamic circulation with an increased cardiac output (153.3 +/- 9.8 vs. 112.6 +/- 6.0 ml/min, P less than 0.005) and portal tributary blood flow (21.32 +/- 1.43 vs. 12.79 +/- 1.47 ml/min, P less than 0.005). Pentobarbital sodium anesthesia induced marked hemodynamic changes in both sham-operated and bile duct-ligated rats. The latter group was especially sensitive to its effects; thus, comparison of cardiac output and portal tributary blood flow between anesthetized bile duct-ligated and sham-operated rats showed no significant differences. We conclude that the rat with cirrhosis due to chronic bile duct ligation is an excellent model for hemodynamic investigations but should be studied in the conscious state, since pentobarbital sodium anesthesia eliminates the hyperdynamic circulation.

Comparison of the circulation between fed and fasted normal and portal hypertensive rats

The radioactive microsphere technique with the reference sample method was used for simultaneous determinations of splanchnic organ blood flow and cardiac output in fed and fasted anesthetized control rats and in rats with portal hypertension due to portal vein stenosis. Portal tributary blood flow was significantly higher in control (27.35 +/- 1.82 versus 14.60 +/- 0.96 ml/min) and in portal hypertensive (25.45 +/- 0.71 versus 20.09 +/- 1.27 ml/min) fed animals than in fasted rats, respectively. This difference was due to an increase in most of the splanchnic organ blood flows expressed in terms of either milliliter per minute or milliliter per minute per gram of tissue. The distribution of the cardiac output to the portal venous territory was also increased in fed animals as compared to fasted rats. In contrast, hepatic arterial blood flow was lower in fed animals than in fasted rats in both groups. Cardiac output was also significantly elevated in fed animals. This study demonstrates that the baseline circulatory state that depends on the digestive condition of these rats must be considered for splanchnic hemodynamic studies.

Ultrastructural observations on folliculo-stellate cells in the pars distalis of the pituitary gland in three rodent species

Ultrastructural features of folliculo-stellate cells of the anterior lobe of the pituitary gland were described in three rodent species (the mouse, guinea pig, golden hamster). These cells are agranular and form the lining of tiny follicles projecting microvilli. Long cytoplasmic expanding processes are intermingled with granular cells of various morphofunctional types without special relationships to one cell type or another. In the guinea pig, the abundance of intermediate filaments appears as a notable feature in the cytoplasm of the folliculo-stellate cells. The results are compared with those previously published.

The human thyrotropic adenoma: pathologic diagnosis in five cases and critical review of the literature

Five out of 400 surgically removed pituitary tumors (frequency: 1.2%) were identified as thyrotropic adenomas according to the following criteria: identification of tumoral thyrotropic cells by immunocytochemistry and ultrastructural study; elevated serum TSH levels with decrease after surgery; and elevated concentration of TSH in the tumor. Four patients presented with hyperthyroidism and one with euthyroidism. From these five cases and 11 similar observations extracted from a critical review of literature, the morphologic, immunocytochemical, and hormonal characteristics of thyrotropic adenoma are described. Thyrotropic adenomas are more often large tumors but may also be microadenomas. The diagnosis is asserted by immunoreactivity with anti-TSH antisera. The TSH positive tumor cells are numerous. In some tumors, rare cells of other types are also found (PRL, GH, FSH, or ACTH cells). Some morphologic characteristics strongly suggest the diagnosis. The cells are often large with thin processes. They show argyrophil granulations in a slightly basophil cytoplasm and signs of secretory activity. Their secretory granules are round and small without striking variations in size, shape, and electron density. Elevated concentration of TSH in the tumor confirms the diagnosis. The presence of high serum TSH levels and a molar ratio of alpha hTSH to the whole TSH molecule greater than one are other good criteria. Decrease of TSH after surgery may not be observed in invasive tumors. TSH adenoma is most often associated with hyperthyroidism but it can also be associated with hypothyroidism or euthyroidism.

Ultrastructural identification of folliculo-stellate cells in the pars distalis of the cat and dog pituitary gland

Ultrastructural features of folliculo-stellate cells of the anterior lobe of the pituitary gland have been described in the cat and dog. These cells are agranular and form the lining of tiny follicles into which microvilli project. Long expanding cytoplasmic processes are intermingled with granular cells of various types without special relationships to one cell type or another. A few features are reported which are peculiar to each species. The results are compared with those previously described.

The human gonadotropic adenoma: pathologic diagnosis and hormonal correlations in 26 tumors

Twenty-six out of 400 surgically removed pituitary tumors were identified as gonadotropic adenomas (frequency 6.25%). Morphologic, immunocytochemical, and hormonal characteristics of the gonadotropic adenoma are described. The following morphologic characteristics may suggest the diagnosis: arrangement in cords of cells showing signs of cellular activity, secretory granules, which vary in electron density, form, and size (mean diameter 150 nm) and which are numerous in the extensions near the capillaries, and a rough endoplasmic reticulum arranged in short cisternae. However, owing to the morphofunctional variations from one adenoma to another, we consider that only immunoreactivity with gonadotropin antisera proves the diagnosis. Because the material used to generate the gonadotropin antisera was purified but not pure, for precise characterization of the immunoreactivity, absorption tests with various antigens have to be performed. FSH-LH adenomas (n = 14), FSH adenomas (n = 7), and alpha-subunit adenomas (n = 5) but no LH adenomas were identified in our series. No evident morphologic difference related to the type of immunoreactivity and to the sex was found. Almost all the tumors were large with visual signs caused by suprasellar extension. A recurrence following adenomectomy was noted with a frequency of 12%. The diagnosis of gonadotropic adenoma was considered preoperatively in six out of 26 patients only, on the basis of increased serum gonadotropin levels. Correlations between hormonal levels and pathologic data were established in 17 patients. Seven tumors were associated with high serum gonadotropin levels (FSH and LH: three patients and FSH alone: four patients). In ten cases, the serum gonadotropin levels were normal but serum alpha-subunit assay had not been performed. For the pathologist systematically testing the adenomas with many antisera, gonadotropic adenomas are not as rare as for the clinician. Immunocytochemical studies with gonadotropin antisera and serum gonadotropic determination must be performed in all tumors, especially in those pituitary adenomas that appear nonfunctional.

Haemodynamic rebound phenomena after abrupt cessation of propranolol therapy in portal hypertensive rats

The haemodynamic effect of sudden termination of propranolol therapy was studied in sham-operated and portal hypertensive rats. All animals were injected with propranolol (20 mg/kg/day) or saline i.p. for 10 days, then had an isoproterenol infusion test performed 48 h or 72 h after cessation of injections. The dose of isoproterenol required to increase the heart rate by 50 beats/min (CD50), was significantly lower in both sham-operated and portal hypertensive rats at 48 h after propranolol withdrawal. Maximum chronotropic response (Rmax), was significantly higher only in portal hypertensive rats at 48 h after propranolol withdrawal. These results show the existence of a transient beta-adrenergic hypersensitivity state following propranolol withdrawal in normal and portal hypertensive rats.

Alteration in response of the portal tributary vascular bed to the beta-agonist dobutamine in rats with extrahepatic portal hypertension

The acute effects of 2 doses of the beta-agonist dobutamine on systemic and splanchnic haemodynamics were studied in normal rats and in rats with portal hypertension due to portal vein stenosis. Cardiac output and splanchnic organ blood flow were estimated with the radioactive microsphere method and portal pressure was measured. Low dose (5 micrograms/kg) of dobutamine did not change significantly arterial pressure and portal pressure but, cardiac output was significantly higher after dobutamine than after placebo in both groups of rats. Similar results were observed with 15 micrograms/kg of dobutamine except for a significant decrease in arterial pressure in portal-hypertensive rats. In sham-operated rats, dobutamine significantly increased portal tributary blood flow; this rise was parallel to cardiac output. In contrast, in portal-hypertensive rats, portal tributary blood flow did not change significantly after dobutamine. Accordingly in the former group, portal tributary vascular resistance significantly decreased, whereas in the latter group, no change in this resistance was observed with a low dose and a significant decrease was noted with a high dose. In both groups of rats, hepatic arterial blood flow was not significantly different after dobutamine than after placebo. This study demonstrates that the vasodilatory response of the portal tributary vascular bed to an increase in cardiac output is altered in anaesthetized rats with portal hypertension due to portal vein stenosis.