Up-regulation of somatostatin receptors by epidermal growth factor and gastrin in pancreatic cancer cells

Interactions between growth factor receptor systems may be important in the regulation of cell growth. The proliferation of pancreatic tumor AR42J cells has been shown to be stimulated by Epidermal growth factor (EGF) and gastrin and inhibited by somatostatin. To analyze the interaction between these different peptides, we explored the influence of EGF and gastrin on the somatostatin receptors. Treatment of AR42J cells with 10 nM EGF or gastrin for 24 hr increased specific binding of [125I] Tyr3SMS to 131 and 147% of that in control cells, respectively. The effect of peptides on [125I]Tyr3SMS binding was time- and dose-dependent, with half-maximal effect at 0.2 +/- 0.03 nM EGF and 0.3 +/- 0.15 nM gastrin. Scatchard plots revealed an increase in somatostatin receptor number of 27 and 80% after 48 hr of treatment with EGF and gastrin, respectively, without any change in receptor affinity. The increase in somatostatin receptor density was accompanied by the enhancement of biological responses to somatostatin. In cells pretreated with EGF or gastrin, the potency of somatostatin for inhibiting vasoactive intestinal peptide-stimulated cAMP content was increased 2-fold as that of somatostatin analog, SMS, for inhibiting cell proliferation. Furthermore, the efficiency of SMS as antiproliferative agent was greatly increased. Vasoactive intestinal peptide or forskolin did not modify [125I]Tyr3SMS binding of control or treated cells. The phorbol ester 12-O-tetradecanoyl phorbol 13-acetate (TPA) did not affect [125I]Tyr3SMS binding. On the other hand, cycloheximide completely blocked the increase in [125I]Tyr3SMS binding induced by EGF and gastrin.(ABSTRACT TRUNCATED AT 250 WORDS)

Serum IgE levels in liver cirrhosis. Contrasting results in alcoholic and non-alcoholic patients

Hypergammaglobulinemia is a well-known feature of liver cirrhosis, but studies on serum IgE in this setting are limited. The present study evaluates serum IgE concentration in a group of cirrhotic patients and examines their relationship with aetiological, clinical and analytical parameters (including liver function tests and hepatic phagocytic activity). The presence of specific IgE against common dietary antigens was also investigated. Total serum IgE was determined by enzyme immunoassay (EIA) in 52 cirrhotics (27 alcoholic and 25 non-alcoholic, including eight virus B and seven virus C-related cirrhosis, three primary biliary cirrhosis, three cryptogenic, three haemochromatosis and one Wilson's disease) and 34 healthy subjects (used as controls). Serum IgE (IU/ml) in controls was not significantly different from that of cirrhotic patients (median 42, range 2-726 vs median 86, range 2- > 1000, respectively) (P = NS). However, serum IgE among alcoholics (median 199, range 19- > 1000) was higher than that of controls (P < 0.001), virus B-related cirrhotics (median 25, range 3- > 1000) (P < 0.05), virus C-related cirrhotics (median 47, range 2-170) (P < 0.05), or non-alcoholic cirrhotics as a whole (median 23, range 2- > 1000) (P < 0.01). High IgE levels (> or = 170 IU/ml) were detected in 55.5% of alcoholics compared with only 12% of non-alcoholic cirrhotics (P < 0.01). Moreover, IgE levels were very high (> 1000 IU/ml) in six patients of the alcoholic group (22.2%) compared with only one non-alcoholic patient (4%).(ABSTRACT TRUNCATED AT 250 WORDS)

Arthroscopic lysis in knee arthrofibrosis

Arthrofibrosis continues to be a difficult complication in articular surgery on the knee. We present our experience in 21 cases of arthroscopic lysis as an alternative to mobilization under anesthesia. The technique begins with the liberation of the adhesions of the suprapatellar pouch, continues down both gutters, and ends with a cleaning of the notch where necessary. When a restriction of patellar mobility persists, we make a retinacular release. The results obtained are very satisfactory, with an average increase in the arc of mobility of 68 degrees. The average gain in mobility at 6 months is significantly greater than that achieved in the immediate postoperative period. Longer follow-up showed no improvement in range of motion after 6 months.

Nicotinic and muscarinic modulations of excitatory synaptic transmission in the rat prefrontal cortex in vitro

The importance of the cholinergic innervation of the neocortex in cognitive functions has been shown in a number of clinical and animal studies. Until recently, attempts to study the mode of action of acetylcholine in the neocortex have concentrated on muscarinic effects, whereas cholinergic actions mediated by nicotinic receptors have been difficult to demonstrate. The present work was undertaken to study the mechanism of action of nicotinic agents on cortical neurons and compare it to muscarinic effects by means of intracellular recordings in a slice preparation. The study was performed in the prelimbic area of the rat prefrontal cortex, a cortical region particularly involved in cognitive processes. Recordings were made from pyramidal cells located in layers II/III and synaptic potentials were evoked by stimulation of superficial cortical layers. Iontophoretic applications of nicotinic agonists (nicotine, dimethylphenylpiperazinium, cytisine) increased the amplitude of the monosynaptic excitatory postsynaptic potential mediated by non-N-methyl-D-aspartate glutamate receptors in 14% (22/159) of cells. This effect was abolished by the selective nicotinic blocker, neuronal bungarotoxin (IC50 = 0.6-0.7 microM) and by dihydro-beta-erythroidine (IC50 = 20-30 microM), whereas hexamethonium, mecamylamine, curare and alpha-bungarotoxin were ineffective. The nicotinic agonists did not change resting membrane potential, input resistance or current-voltage relationship. They also did not affect the depolarizations produced by glutamate applied by iontophoresis in the somatic or dendritic area. In contrast, the muscarinic agonists (muscarine, acetyl-beta-methylcholine) decreased the amplitude of the excitatory postsynaptic potential in 100% of the neurons tested. Atropine was more effective (IC50 = 0.08 microM) than pirenzepine (IC50 = 2 microM) to antagonize the muscarinic action. These effects were observed in the absence of any direct postsynaptic change in membrane potential or input resistance, provided that the site of the iontophoretic application was more than 100 microM distant from the soma. The muscarinic agonists did not influence the actions of iontophoretically applied glutamate. These results suggest that nicotinic and muscarinic agonists modulate excitatory synaptic transmission mediated at dendritic sites by non-N-methyl-D-aspartate glutamate receptors, possibly through a presynaptic action. Thus ascending cholinergic systems may take part in information processing in the prefrontal cortex through the control of ongoing excitation to pyramidal cells.

Influence of Kupffer cell phagocytosis blockade on the production of ovalbumin-specific IgE and IgG1 antibodies in an experimental model

The aim of the present study was to evaluate the influence of Kupffer cell phagocytosis blockade (KCPB) on the production of reaginic (IgE) and non-reaginic (IgG1) ovalbumin antibodies in an experimental animal model. Forty-two female heterozygous Gunn rats were injected with two 100 micrograms doses of ovalbumin separated by 13 days, into jugular vein (Group I, n = 10), portal vein (Group II, n = 10), jugular vein with prior KCPB (Group III, n = 10) and portal vein with prior KCPB (Group IV, n = 12). KCPB was induced with gadolinium chloride (5 mg/kg body weight, 24 hr before each ovalbumin administration). Antibodies were determined by passive cutaneous anaphylaxis in sera obtained 12 days after the first dose of ovalbumin and 8 days after the second one. No antibodies were detected at any time in Group II. The maximum response was observed in Group IV in which, after two doses of ovalbumin, 100% of the animals presented IgG1 and 58% presented detectable IgE antibodies. Differences between group IV and the other groups were statistically significant. This phenomenon does not seem to be due to a systemic effect of gadolinium chloride since humoral response was not increased in Group III with respect to Group I. It is concluded that the liver represents a barrier to IgE and IgG1 sensitization. KCPB not only eliminates this barrier, but also clearly increases antibody production to a protein antigen (ovalbumin) arriving at the liver through the portal vein.

[Rapid method for identifying Escherichia coli and species of the Proteeae tribe in urine]

BACKGROUND

To evaluate the possibility of using the determination of beta-glucuronidase and phenylalanine deaminase activity directly from urine samples for rapid detection (2 hours) of the presence of Escherichia coli and species of the Proteeae tribe.

METHODS

To detect beta-glucuronidase activity methyl-umbelipheryl-beta-D-glucuronic was used as a substrate. The presence of fluorescence after incubation at 37 degrees C for 2 hours indicated a positive reaction. While phenylalanine was used as a substrate for detecting phenylalanine deaminase activity, FeCl3 was added after incubation at 37 degrees C for 2 hours with a greenish color being observed indicating phenylalanine deaminase activity.

RESULTS

The detection of Escherichia coli by beta-glucuronidase activity presented sensitivity and specificity of 0.91 and 0.99, respectively. The positive predictive value was 0.96 and the negative predictive value was 0.98, whereas the determination of the phenylalanine deaminase activity with the aim of detecting species of the Proteeae tribe presented the following results; sensitivity 0.92, specificity 0.99, positive predictive value 0.94 and negative predictive value 0.99.

CONCLUSIONS

The determination of beta-glucuronidase and phenylalanine deaminase activities directly from urine sediment has been demonstrated as a rapid and specific test for detecting the presence of Escherichia coli and species of the Proteeae tribe, therefore it must be considered as a useful test in early diagnosis of urinary infection thereby facilitating the administration of appropriate antibiotic treatment.

Characterization of a membrane tyrosine phosphatase in AR42J cells: regulation by somatostatin

A phosphotyrosyl protein phosphatase (PTPase) activity has been characterized in the plasma membranes of confluent AR42J pancreatic tumor cells using 32P-labeled poly(Glu, Tyr) as substrate. Membrane PTPase activity exhibited an apparent Michaelis constant of 3 microM and an apparent maximal velocity of 0.9 nmol.min-1.mg-1. It was inhibited by orthovanadate, zinc, poly(Glu,Tyr) and was stimulated by EDTA and dithiothreitol. Gel filtration of solubilized plasma membranes gave a peak of enzyme activity at a relative molecular weight of 70,000. Plasma membrane PTPase activity was changed during AR42J cell growth. At the beginning of culture, the control PTPase activity was minimal. Over the 5 days of culture, PTPase activity increased to reach a maximum (3.5-fold over control activity) preceding confluency by 2 days. Then the high level of PTPase activity was sustained until confluency. Incubation of the cells with the stable somatostatin analogue SMS 201-995 (SMS) resulted in a rapid and transient activation of crude membrane PTPase activity. Activation reached a maximum level within 5 min of addition and return to control levels within 20 min. The effect of SMS was dose dependent with half-maximal and maximal activation occurring at 6 pM and 0.1 nM SMS respectively.

Basic fibroblast growth factor induces proliferation of a rat pancreatic cancer cell line. Inhibition by somatostatin

AR4-2J, a rat pancreatic acinar-tumor cell line, was used to investigate long-term effects of basic fibroblast growth factor (bFGF) and somatostatin on pancreatic cancer cells. We observed that bFGF stimulated cell proliferation when cells were cultured in serum-free medium. The effect was dose-dependent with half-maximal and maximal effects at 25 pM and I nM bFGF, respectively. The somatostatin analog SMS 201-995 (SMS) decreased the growth-promoting effect of bFGF. The maximal effect was observed at I nM SMS and the half-maximal effect at 20 pM SMS. Characterization of bFGF receptor-binding properties with [125I]bFGF revealed that AR4-2J cells exhibited 2 classes of bFGF binding site with respective KD values of 47 pM and 3 nM and binding capacities of 14 fmol and 0.9 pmol/10(6) cells. High-affinity receptors correlated with bFGF stimulation of AR4-2J cell growth, suggesting that the effects of bFGF are receptor-mediated.

Three cases of allergic dermatitis due to intravesical mitomycin C

Irritant contact dermatitis has frequently been described in association with mitomycin instillation into the bladder. Three cases of allergic contact dermatitis in which patch tests demonstrated a type IV hypersensitivity reaction are reported. Patients showing skin reaction during mitomycin C vesical instillation should be patch tested to make a decision whether the drug might be continued (toxic reaction) or discontinued (allergic reaction).

Bronchial asthma due to Cannabis sativa seed

A 51-year-old man with asthmatic attacks due to Cannabis sativa seed inhalation was studied. Specific IgE against this seed was demonstrated by in vivo (skin and bronchial challenge tests) and in vitro methods (reverse enzyme immunoassay and histamine release from basophils), suggesting a Type I immunologic reaction.

Existence of different subtypes of nicotinic acetylcholine receptors in the rat habenulo-interpeduncular system

Neuronal nicotinic ACh receptors (nAChRs) are present in the rat medial habenula (MHB) and interpeduncular nucleus (IPN), two brain regions connected through the fasciculus retroflexus (FR). The goal of the present study was to compare the electrophysiological and pharmacological characteristics of nAChRs located at pre- and postsynaptic sites within the MHB-IPN system. nAChRs located on the soma of IPN neurons were studied using patch-clamp techniques and a preparation of acutely isolated neurons. Whole-cell currents evoked by Ach and nicotine showed an intense rectification at positive membrane potentials. nAChR channels were relatively nonselective for cations, had a unitary conductance of 35 pS, and were activated by several nicotinic agonists with the following rank order: cytisine greater than ACh greater than nicotine greater than dimethylphenylpiperazinium (DMPP). They were blocked by mecamylamine, hexamethonium, curare, and dihydro-beta-erythroidine (DHBE), but were insensitive to alpha-bungarotoxin and neuronal bungarotoxin. In contrast, nAChRs recorded on the soma of MHB neurons under equivalent experimental conditions exhibited different characteristics for single-channel conductance and agonist and antagonist sensitivity. The pharmacological properties of presynaptic nAChRs in the IPN were analyzed in a rat brain slice preparation. Stimulation of the FR produced a presynaptic afferent volley recorded in the rostral subnucleus of the IPN. Nicotinic agonists decreased the amplitude of the afferent volley with different efficacies: nicotine greater than cytisine greater than ACh greater than DMPP. The action of nicotine was insensitive to alpha-bungarotoxin and to neuronal bungarotoxin, but was blocked by mecamylamine, hexamethonium, curare, and DHBE, with IC50 values different from those reported for IPN postsynaptic nAChRs. This study thus demonstrates the functional diversity of nAChRs in the rat CNS.

[Spontaneous bacterial peritonitis: occurrence in chronic liver disease patients in Recife]

A prospective research was made on spontaneous bacterial peritonitis (SBP) in chronic liver disease patients presenting with ascites. Forty clinical cases, of 37 patients, were analysed. All subjects were submitted to clinical and laboratory evaluation and diagnostic paracentesis, and the material was obtained for biochemical dosages, pH determination, cytology and bacterial cultures. Thirty cases of sterile ascites and 10 of SBP (25%) were detected. In 5 (50%) with SBP, the clinical findings were characteristic, with fever, abdominal pain and rebound tenderness. In 2 patients (20%) the presentation was atypical, without the complete triad described above. Finally in 3 (30%) SBP was silent, without any suggestive clinical manifestations of infection. In 7 cases (70%) cultures were positives; Streptococcus pneumoniae (3 cases), Streptococcus pyogenes, Staphylococcus negative coagulase, Staphylococcus aureus and Klebsiella pneumoniae (one case each). In 7 (70%) SBP cases, the patients were admitted already infected in the hospital. Lethality in the SBP group was 30% and in the sterile ascites was 13.3%. We concluded that SBP is a frequent cause of morbid-lethality in patients with ascites and chronic hepatopathy, presenting itself often in a typical clinical manifestations.

Tracheobronchomegaly associated with interstitial pulmonary fibrosis

Tracheobronchomegaly (TBM) is the syndrome of enlarged trachea and main bronchi associated with recurrent and chronic respiratory tract infections. A 42-year-old man with TBM and diffuse interstitial pulmonary fibrosis is described. The possible relationship between the two entities is discussed and the etiology, pathogenesis, clinical manifestations, prognosis and treatment of TBM are reviewed.

Seborrheic dermatitis and HIV infection. Qualitative analysis of skin surface lipids in men seropositive and seronegative for HIV

We measured skin surface lipids (cholesterol, free fatty acids, triglycerides, wax esters, and squalene) in patients seropositive for human immunodeficiency virus (HIV) and those seronegative for HIV with and without seborrheic dermatitis. Cholesterol and wax ester fractions were similar in all four groups but triglycerides and squalene were significantly increased and free fatty acids significantly decreased in HIV-positive patients, regardless of the presence of seborrheic dermatitis. In addition, a strong negative correlation was found between free fatty acid and triglyceride levels. We conclude that abnormalities of skin surface lipids are not associated with the development of seborrheic dermatitis in HIV-positive persons but are associated with HIV infection itself.

[CAMDEX: a new psychogeriatric interview]

"The Cambridge Mental Disorders of the Elderly" (CAMDEX) is a new structured interview developed for diagnostic of dementia and other psychogeriatric disorders frequent in the old age. The CAMDEX is composed of three main sections: 1) A clinical interview structured to obtain from the patient a systematized information about his present condition, his antecedents and his familiar history. 2) A short neuropsychological battery formed by several cognitive tests. 3) A structured interview to obtain independent information about relative or another informing person about the present state of the patient, his antecedents and his familiar history. The good results obtained by the original version of CAMDEX, as in clinical works as in epidemiological ones, have determined their translation and fitting in our environment. The present work shows the changes that have been necessary to insert in the original version in order that this interview may be used in our geriatric population.

[The Cambridge Mental Disorders of the Elderly Examination. Study of interobserver reliability]

Three teams formed by psychologists with experience in the administration of structured interviews evaluated by the CAMDEX (The Cambridge Mental Disorders of the Elderly Examination) in a sample of 41 patients for the interrater reliability study. While a psychologist interview patient, the other one observes each patient. The CAMDEX were completed independently by each of the examiners. The results demonstrate an elevated level agreement both for the different scales (p less than 0.001) and for the different diagnostic criteria employed by the CAMDEX (kappa = 0.88 for the DSM-III-R and Kappa = 1 for the ICD-10).

[The Cambridge Mental Disorders of the Elderly Examination. Validation of the Spanish adaptation]

A neurologist and a psychiatrist diagnosed independently, according to DSM-III-R and ICD-10 criteria, to 15 subjects with dementia, 15 with depression and 15 without any of two previous diagnostics. Later, a psychologist held an interview with them by means of the structured interview CAMDEX. The lump levels of agreement between clinical diagnostic and DSM-III-R diagnostic obtained through CAMDEX is of Kappa = 0.63. These levels are increased to one Kappa = 0.76 if we compare the clinical diagnostic with CAMDEX diagnostic according to the ICD-10. On the other hand, we value the outputs of some instruments that are included in the CAMDEX: Mini Examen Cognoscitivo, Mini-Mental State, CAMCOG, Organicity Scale, Blessed Scale and Depressión Scale.