Study on the histamine-like activity of guanfacine

The effects of guanfacine have been studied on guinea-pig isolated atria and diethylstilboestrol-treated rat isolated uterus to determine whether it possesses histamine-like activity. Guanfacine produced a concentration-dependent negative chronotropic effect which was not modified by ranitidine (0.1 microM). In rat isolated uterus contracted by KCl, clonidine (5-5000 microM) produced concentration-dependent relaxation which was blocked by ranitidine (0.1 microM), but guanfacine only produced relaxation at high concentrations (100-1000 microM), and this was not affected by ranitidine (0.1 microM). It is concluded that guanfacine, unlike clonidine, does not produce effects due to activation of H2-receptors in either guinea-pig atria or rat uterus.

Surgery of the parotid region: a new approach

Many disorders of the parotid gland require treatment by subtotal or total parotidectomy. In such situations functional and esthetic complications may arise due to the location of the incisions or from permanent or temporary injuries to the facial nerve. This report describes a modified revision that gives good esthetic and functional results. A review of a similar series of cases treated surgically by the same surgeons using Yoel and Bilesio's technique showed no differences in morbility associated with parotidectomy performed using the proposed incision.

Studies of the spontaneous motility and the effect of histamine on isolated myometrial strips of the nonpregnant human uterus: the influence of various uterine abnormalities

We investigated the spontaneous uterine activity of isolated corpus uteri myometrial strips from 30 patients with nonpathologic myometrium, 26 patients with uterine myoma, 23 patients with uterine adenomyosis, and three patients with uterine malignancy. We also investigated the influence of these conditions on the response of the uterus to histamine. The results show the same qualitative cyclic changes of the spontaneous motility of isolated myometrial strips throughout the menstrual cycle in all the abnormalities studied. These changes are characterized by a low amplitude and high frequency of spontaneous contractions in the proliferative phase and lower frequency with higher amplitude of contractions in the secretory phase. The isolated strips from patients with myomas present the highest spontaneous activity in reproductive age and preclimacteric women, but not in menopausal women. Histamine produced concentration-related contractions that are not significantly different in all the myometrial strips studied.

[Treatment of cerebrospinal fluid shunt infections using the Perrin and McLaurin technique. Analysis of 11 cases]

Eleven patients with shunt infection (SI) of the cerebrospinal fluid in whom the SI was withdrawn and replaced by a new SI system with reservoir and intraventricular and parenteral antibiotic treatment were reported. The diagnosis was made by culture of the components of the SI and, or, the cerebrospinal fluid. In 9 cases the agent was a staphylococcus. The different therapeutic trials to treat SI infections can be summarized as follows: a) replacement of the SI by an external drainage, antibiotics, and reinsertion of the SI when the cerebrospinal fluid was sterilized; b) withdrawal of the SI and placement of a new SI in the same surgical procedure associated with intraventricular and systemic antibiotic treatment; and c) treatment with intraventricular and, or, systemic antibiotics. It has been demonstrated that the surgical approach (a and b) is more effective. In our series the procedure indicated in B was followed by the control of the infection in all cases. The follow-up of the surgical treatment was 1-3 years. The most currently used SI was the ventriculoperitoneal bypass. Their main complications are pseudocysts which are easily recognized by of abdominal echography and frequently revealed SI infection. Diagnosis and treatment of SI infections should take into account the type of complications and the most appropriate collaboration with other clinical departments.

[The diagnosis of perioperative myocardial infarction in heart surgery]

Fifty three consecutive patients undergoing open heart surgery were prospectively studied to assess current techniques for diagnosing perioperative myocardial infarction (PMI). All patients had preoperative and postoperative electrocardiograms, serial determinations of serum creatine phosphokinase (CK), myocardial fraction of CK (CK-MB) and scintigraphy with technetium-99m labeled pyrophosphate. Seven patients (13.2%) sustained perioperative myocardial infarction. Four of these patients exhibited abnormal Q waves, and one poor R wave progression. Three of them had a positive scintigram. Two patients with a non-Q-wave infarction had a abnormal radioisotopic imaging. The CK and CK-MB were higher in patients with infarction (818.1 U) than in those without this complication (349 U) p less than 0.05. The relative sensitivity and relative specificity of given variables in the diagnosis of PMI were as follows: electrocardiogram 71.4% and 97.5% respectively; scintigraphy 71.4% and 94.1%; and serum enzymes 100% and 71.8%. Age, incidence of prior myocardial infarction, unstable angina, elevated left ventricular filling pressure, number of diseased coronary arteries, and number of grafts per patient did not correlate with PMI. Duration of extracorporeal circulation and number of electric shocks during surgery were slightly higher in the infarction group, but the difference was not significant. These results indicate that the combination of these three diagnostic procedures is the best way to evaluate myocardial damage after open heart surgery.

[Importance and characteristics of burns in a pediatric emergency service]

The purpose of this study was to describe the magnitude and some relevant aspects of children with burn injuries as seen at the emergency room of a metropolitan hospital at Santiago, Chile, from a random sample of 22,430 consultations from a total of 137,220. Two hundred and thirty seven burn injuries were detected corresponding to 5.2% of all surgical consultations and 1.1% from the whole sample, 56.5% occurring in males, 73.4% of the affected patients were under 5 years of age, 72% of lesions were caused by hot liquids, 51.6% affected the upper limbs and 4.5% were considered to require admission to hospital wards. Consultations most frequent in july (winter) the lesser incidence occurring in february (summer). Preventive programs addressed to burn injuries should cover children under 5 years of age and should be specially focussed on winter and safe handling of hot liquids.

The susceptibility to amoxycillin/clavulanate of Enterobacteriaceae with plasmid-mediated ampicillin resistance: a twelve-year study of strains in one Spanish hospital

We studied the antibacterial activity of amoxycillin, clavulanic acid and the combination, against 1210 clinical isolates with plasmid-mediated ampicillin resistance, isolated at the Zaragoza Clinical University Hospital during 12 years. MICs were determined by an agar dilution technique with an inoculum of 10(4) cfu per spot. MIC50 values of amoxycillin/clavulanate ranged from 8 to 16 mg/l. The antibacterial activity of amoxycillin/clavulanate did not show any statistically significant variation during the 12-year period.

Diffuse axonal injury after severe head trauma. A clinico-pathological study

Diffuse Axonal Injury (DAI) is a well known entity that affects many patients with severe head trauma. Classically DAI has been considered the pathological substrate of those cases rendered unconscious at the moment of impact and in which the CT scan does not show mass lesions. Diffuse axonal damage is almost always related to mechanisms of injury in which the rotational acceleration produces shear and tensile strains of high magnitude. In this paper we present a group of 24 patients with a severe head injury in whom the postmortem examination demonstrated unequivocal signs of DAI. Widespread axonal retraction balls, located preferentially in the centrum semiovale and internal capsule were the most constant histological finding. We divided the entire series into two subgroups. One group (15 cases), included all the patients in whom the CT scan did not demonstrate mass lesions. In the second group (9 patients) we considered patients with a diffuse axonal injury in whom the CT scan additionally demonstrated a mass lesion (6 acute subdural haematomas, 2 intracerebral and 1 extradural haematoma). The mean age of the entire group was 26 years. Twenty two patients were injured in a road traffic accident, the remaining two fell from a considerable height. All were rendered immediately unconscious on impact. Diffuse brain damage is a common finding in patients with a severe head injury and immediate coma in whom the CT scan does not show mass lesions. Diffuse axonal injury can also appear in connection with a wide spectrum of focal lesions (acute subdural haematoma, basal ganglia haematoma etc.).(ABSTRACT TRUNCATED AT 250 WORDS)

[Evaluation of post-traumatic coma using evoked potentials]

In 130 cases of post-traumatic coma a study of multimodality evoked potentials (MEP) was carried out shortly after the traumatism (within 72 h). According to the morphology of the records they were classified in grades (I-IV) in agreement with Greenberg et al. The worst grade of EP in the different types was related to the outcome at 6 months, distinguishing between focal lesions and diffuse lesions. Only a group (22.9%) of the 109 patients in which the auditory brain-stem evoked potentials (ABEP) could be studied, showed severe disorders (grade III-IV). There was a significant correlation between the ABEP grades and the outcome in the focal lesions (p less than 0.001). In the diffuse lesions the ABEP grades did not show significant differences with the outcome. A 22.4% of the patients with diffuse lesions had some visual evoked potentials (VEP) in grades III-IV against almost the double (41.6%) in the focal lesions. The grades of the VEP in the focal lesions did not have differences with outcome and in the diffuse lesions they did (p less than 0.05). Approximately half of the cases with focal lesions and one third of the diffuse lesions showed severe disorders (grades III-IV) of the somatosensory evoked potentials (SEP). In the two types of lesions there were significant differences with the outcome (p less than 0.001) and (p less than 0.01). The multimodality evoked potentials (MEP) are useful for predicting the outcome, especially in the patients where the neurological examination is impossible. Among the different modalities, the SEP were shown to be more predictive.(ABSTRACT TRUNCATED AT 250 WORDS)

Relaxant effect of dopamine on the isolated rat uterus

The effect of dopamine was studied on the isolated uterus of diethylstilboestrol-treated rats. Dopamine, at concentrations (10(7)-10(-4) M) produced a concentration-dependent relaxation in the K+-depolarized rat uterus. On a molar basis, dopamine was about 500 times less potent than adrenaline in relaxing the uterus, the maximum degree of relaxation obtained with both drugs was the same. Pretreatment of the rats with reserpine (5 mg/kg) did not produce any modification of the dose-response curve to dopamine. Similarly, cocaine (3 x 10(-6) M) failed to modify the relaxant effect of dopamine. The dopamine induced relaxation was inhibited by propranolol (10(-9)-10(-7) M) in a dose-dependent manner. Prazosin (10(-7) M), SCH 23390 (10(-7) M) and sulpiride (10(-7) M) did not affect the dopamine dose-response curve. In the isolated rat uterus which was not preconstricted by KCl neither dopamine nor adrenaline produced any effect when added to the organ bath. This lack of response to both catecholamines was present even in tissues pretreated with propranolol or sulpiride. It is concluded that dopamine produced a concentration-dependent relaxation of the uterus from diethylstilboestrol-treated rats by direct activation of beta-adrenoceptors. There was no evidence for indirect action (catecholamine release and neuronal uptake mechanisms) and specific dopamine receptor mediated relaxation and alpha-adrenoceptor mediated contractions have not been found in this preparation.

Effect of domperidone on the contractility of isolated guinea-pig atria

This study was undertaken to investigate whether or not dopamine receptors are responsible for the cardiac action of domperidone and to gain a better understanding of the mechanism of the cardiac effects of this compound. In isolated electrically driven guinea-pig atria, domperidone (0.1-30 microM) produced a negative inotropic effect (-56.7 +/- 4.9% at 30 microM) and at a concentration of 0.1 microM significantly decreased the positive inotropic response to histamine (0.5-271 microM). In spontaneously beating guinea-pig atria, domperidone failed to modify the chronotropic responses elicited by dopamine and noradrenaline. In the isolated guinea-pig ileum, domperidone alone did not produce any effect, but produced a right-ward displacement of the contractile dose-response curve to histamine. At concentrations of 0.01, 0.1 and 1 microM, domperidone also depressed the maximum response to histamine. The results obtained suggest that the negative inotropic effect of domperidone is not due to dopamine or adrenergic receptor antagonism. This cardiac effect of domperidone can be partially explained by its influence on the effects of histamine acting on H1-receptors, although other mechanisms may be involved.

Antihistaminic and anticholinergic activities of mequitazine in comparison with clemizole

The antihistamine and anticholinergic properties of mequitazine have been investigated and compared with those of clemizole. Both mequitazine and clemizole antagonized the effect of histamine in guinea-pig ileum competitively, the pA2 values calculated by Schild plot were 9.95 +/- 0.44 for mequitazine and 10.54 +/- 0.44 for clemizole. Mequitazine at 10(-7) M produced a parallel shift of the dose-response curve to acetylcholine in the rat duodenum, clemizole and the lower doses of mequitazine failed to modify the effect of acetylcholine. The potency of mequitazine and clemizole as H1-histamine blockers is similar, but only mequitazine at highest concentration used showed anticholinergic activity.

[Spontaneous cerebellar hematoma. Analysis of 23 cases]

A series of 23 patients with spontaneous cerebellar hematoma is analysed retrospectively. Several degrees of consciousness impairment, and headache occurred in all; 12 patients presented motor deficits among the more important clinical signs. Arterial hypertension (69.5%) and diabetes (34%) stand out in the pathological background, and their association was frequent (30%). Computerized tomography (CT) disclosing severe ventricular dilatation (69.5%) associated or not with intraventricular presence of blood is considered as an unsatisfactory prognosis sign, and indicative for emergency therapy. Emergency external ventricular draining is the best indication for the majority of these cases. Posterior fossa craniectomy for emptying the hematoma may be the indication in severe cases. Death and morbidity in this pathology are high as yet. However, CT contribution for diagnosis is quicker and better than benefits obtained through other methods. Results observed in the present series are illustrative on this statement, when compared to data of other series diagnosed through other methods.

The lack of the effect of DA-1 and DA-2 dopamine agonists on the isolated guinea-pig atria

1 The effects of dopamine and both DA-1 and DA-2 dopamine receptor agonists have been studied on the contractile force of electrically driven guinea-pig left atria and frequency of spontaneously beating right atria. 2 Pretreatment of animals with reserpine caused a parallel rightward shift of the concentration-response curve to dopamine of either preparation. 3 Propranolol, but not domperidone, shifted to the right the dose-response curve for the positive inotropic and chronotropic effects of dopamine. 4 Neither apomorphine, fenoldopam, bromocriptine nor piribedil had effects on the frequency and contractile force of the isolated guinea-pig atria. 5 These results suggest that DA-1 and DA-2 dopamine receptors are neither directly nor indirectly (prejunctional effect) involved in the inotropic and chronotropic effects of dopamine in isolated guinea-pig atria.