Posterior fossa arteriovenous malformations. Angioarchitecture in relation to their hemorrhagic episodes

Classically, posterior fossa arteriovenous malformations (PF-AVMs) have been considered as lesions with high tendency to bleed. However, careful analysis of clinical and autopsy data from the literature demonstrate that in fact the incidence of hemorrhage is similar in infratentorial and supratentorial locations. The clinical perception that most of the diagnosed PF-AVMs had bled does not mean that they have a high risk of hemorrhage. It suggests that bleeding is the dominant way of expression, since other symptoms are uncommon. Furthermore, angioarchitectural analysis is similar in supra- an infratentorial locations. The causes of hemorrhage are probably related to venous anatomic and hemodynamic changes or associated aneurysms as in other intracranial AVMs.

Effects of fusidic acid on staphylococcal keratitis

We treated 20 consecutive patients suffering from staphylococcal keratitis with topical fusidic acid 1% suspension in a carbomer gel. Fifteen (79%) of the isolated Staphylococcus epidermidis strains were resistant to methicillin, but all were sensitive to fusidic acid by in-vitro testing. The keratitis showed evidence of healing in 17 (85%) of the 20 patients. The healing times ranged between 5 and 21 days (mean 10.5 days). In this open clinical trial fusidic acid proved to be a safe and effective antibiotic for the treatment of staphylococcal keratitis.

[Normal and pathological ultrasonography of the fetal brain]

Advanced ultrasonic technology enabled the bidimensional imaging of fetal brain throughout pregnancy. The number of visible structures increases with gestational age. In order to certify the described items they were compared to similar anatomical sections available from brain specimens or an atlas of anatomy. Real-time as well as automatic compound scanning machines were used to obtain echographic images of fetal brain anatomy in utero. Many different scans were collected along three orthogonal directions: every 2 mm, with the automated compound scan and as close from each other as possible with the linear array real-time scanner. The material included 59 normal fetuses between the 15th and 40th week of gestation. Eight typical sections are made but the only structures identified are those being visible on every section obtained at the same level. Brain structures such as grey and white matter, nuclei, vessels and ventricles have different sonic properties. They are subsequently distinguishable on the ultrasonic image if the equipment is capable of detecting and showing such differences. Grey matter is more echogenic than white, choroid plexuses are very reflective as are vessel walls which also pulsate. Four horizontal sections are described in detail (Figs. 2-7). The coronal planes are demonstrated at three different levels (Figs. 8-12) and the sagittal plane is represented by Fig. 13. Thirty five structures were identified (Table 2). In the second section some brain and skull anomalies are briefly described. The principal signs of the abnormalities and possible encountered variations are listed such as cranial defects in anencephaly, acrania, encephalocele, iniencephaly; the anomaly of size and shape of head and ventricle, as in hydrocephaly and microcephaly, cystic-like- and solid-tumor lesions and Dandy Walker syndrome and hydranencephaly. Attention is drawn to possible artifacts and pitfalls in the differential diagnosis between similar looking pictures. Examples are given such as noise in the near field, occurring more often in sectorscan machines, inadequate orientation of scan plane producing asymetrical display of the hemisphere and the Sylvian fissure described as if it was the lateral ventricle wall. Anomalies can also be confused such as exencephaly, anencephaly, iniencephaly, encephalocele. An excellent knowledge of normal brain anatomy and pathology, together with excellent equipment and a careful scrutiny of the echograms are required qualities for fetal brain examination.

Effect of hyperventilation and starvation on rat lung mechanics and surfactant

We studied the effects of hyperventilation and starvation on rat lung mechanics and surfactant. We hyperventilated lungs by excising and ventilating them at 3 times the normal tidal volume. Three days starvation reduced the alveolar pool of disaturated phosphatidyl choline by about 20% but did not significantly reduce the functional residual capacity. Air and saline deflation pressure-volume curves were performed in 4 groups: control lungs, lungs from starved rats, hyperventilated lungs, and hyperventilated lungs from starved rats. The area under each curve was calculated; this indicated the relative position of the curve in the pressure-volume diagram. We found that starvation did not change recoil, that hyperventilation increased surface recoil, and that combined starvation and hyperventilation increased it even more. We conclude that hyperventilation-induced dysfunction of surfactant is greater when the alveolar pool of surfactant is reduced by starvation. This effect might also occur clinically in the intensive care setting.

Single dose treatment with praziquantel (Cesol R, EmBay 8440) of human cestodiasis caused by Diphyllobothrium pacificum

Diphyllobothrium pacificum, a large tapeworm of seals, is often found as an accidental parasite of man in Perú. The main symptoms is causes are abdominal pain, meteorismus and flatulence, and diarrhea. We report the results of 32 single-dose (10 mg/kg weight) treatments with Praziquantel (Cesol R, EmBay 8440) in 31 patients. One of these patients was shown to be cured but presented a reinfection 270 days later, and required retreatment. Praziquantel was effective in all cases. All patients were clinically cured. No ova were found in stool examinations at 30, 60, and 90 days after treatment, while pretreatment stools were positive for ova with all the techniques used. The antiparasitic effect was evident in 11 cases which segments of the tapeworm were eliminated within the first 3 days of treatment: the fragments were all partially digested or autolysed. A treatment scheme incorporating a purge may be best, to recover the parasite in its entirety and thus ascertain cure with no repeated controls.

Spontaneous contractility of human placental vessels in vitro axipetal and isometric recording

In vitro contractility of isolated cylindrical segments of chorial arteries and veins from 40 human term placentas was studied. Contractility was recorded by an isometrical and axipetal method. Spontaneous contractility was observed in 75% of the arteries and in 45% of veins. In both types of vessels, contractility was similar and characterized by development of tonic circumferential tension, between 100 and 200 mg/mm. Clonic activity consisting of rhythmic contractions with an average frequency between 0.7 and 0.9/min and an average intensity of 5--40 mg/min was superimposed. Vasoconstrictor drugs (PGF2 alpha, histamine and adrenaline) increase tonic tension without modifying the frequency of clonic activity. It is suggested that spontaneous contractility may be the expression of myogenic excitability related to the regulation of fetal placental blood flow.

Pathology of the trophoblast and fetal vessels of the placenta in maternal diabetes mellitus

The morphologic characteristics of the chorial villi from normal full-term placentas and from placentas of different clinical types of diabetic women were studied. The latter showed early maturation of the trophoblast, higher percentage of villi with stromal edema, and higher percentage of vessels of the villous trunks with lesions causing partial or total obstruction of the vascular lumen. The fact that the diabetic patients were treated suggests that the metabolic correction of diabetes mellitus prevents the occurrence or development of the multiple disturbances which the disease produces in the evolution of human pregnancy.

A rapid response system for out-of-hospital cardiac emergencies

We have reviewed several aspects of our initial 5 years' experience with an out-of-hospital emergency medical care system. This system is stratified and provides for rapid primary response and, when indicated, secondary response by specially trained paramedical personnel. Patient care is physician-supervised and closely monitored. Although considerable attention has been directed to acute complications of ischemic heart disease, particularly the problem of sudden cardiac death, the system is broadly based and responds to all medical emergencies. We are impressed with the ability of nonphysicians to acquire certain medical skills and judgment. Indeed, the effectiveness of this system is largely dependent on paramedical personnel. Such systems of prehospital emergency medical care will probably have an impact greater than that of hospital coronary care units in reducing the mortality from ischemic heart disease.

Critical closing pressure in the fetal vessel of the human placenta in vitro. II. Compared effects of a beta adrenergic substance, Salbutamol, on the critical closing pressure and vascular resistance

Salbutamol effects upon the fetal vessels of the human placenta were studied in vitro, comparing the changes induced upon the critical closing pressure (CCP) and viscous resistance (R). Four normal full-term placentas were used. In each of them, 4 cotyledonary areas were perfused, thus obtaining a total of 16 measurements for the observation of spontaneous variations (blank), by perfusion with Krebs solution, and the same amount for the variations due to Salbutamol. The concentration used was 10 microgram/ml, with a 4.25 ml/min flow. The relative effect of Salbutamol upon CCP was its decrease--30.4% against a relative spontaneous variation of --3.6%. The mean relative effect upon R was much lower, --9.4%. against a mean relative spontaneous variation of + 3.3%. The advantages of using CCP instead of R as a parameter of vascular contractility are discussed. Furthermore, Salbutamol is suggested to be useful in improving fetal placental circulation.

Resuscitation from out-of-hospital ventricular fibrillation: 4 years follow-up

In 51 months, 234 patients with out-of-hospital ventricular fibrillation (VF) were successfully resuscitated, hospitalized, and discharged home. Patients surviving an episode of primary ventricular fibrillation, that is, VF not associated with acute myocardial infarction, showed a 2-year mortality rate greater than three times that of survivors from VF associated with acute transmural infarction. Recurrent out-of-hospital VF was common, and a pattern of early recurrence was noted, with a median interval of 17 weeks in 34 documented cases. Ten patients were counted as long-term survivors from second episodes of out-of-hospital VF, one of whom survived a third episode. Coronary anatomy and ventricular function were studied in 29 survivors of primary VF. Of the 29 patients, 23 had coronary disease, considered "operable" in 17. Exercise testing and left ventricular function studies were normal or minimally abnormal in approximately half of these patients. There is an obvious need to develop effective measures to prevent primary VF, which commonly presents almost instantaneously, without prodromal symptoms.

Total water content in different areas of the human term placenta

The authors study the total water content in two different areas (parabasal and subchorial), in 40 normal, full-term placentas. The water content is found to be different in these two areas. As an average, it is 0.90% higher in the parabasal area. This difference persists even after washing off the fetal placental blood by perfusión with saline. The difference in the total water content between both areas, which is added to other differences previously demonstrated, must be related to a different functional role of the placental areas.

Survival after resuscitation from out-of-hospital ventricular fibrillation

During the first three years in operating a comprehensive system for the management of out-of-hospital medical emergencies, 146 patients were resuscitated from ventricular fibrillation, hospitalized, and discharged home. The diagnosis of acute transmural myocardial infarction associated with the episode of ventricular fibrillation was confirmed in only 17% of the patients. The presence of myocardial necrosis, based on either evidence of new transmural infarction or LDH-isoenzyme criteria was established in 49.5% of the patients. During the follow-up period, averaging 418 days, 43 of the 146 patients died. Thirty-four of the 43 deaths occurred suddenly outside the hospital. Patients whose aborted sudden cardiac death was associated with acute transmural infarction had a mortality rate of 14% after two years of follow-up. In contrast, patients without evidence of acute myocardial necrosis had a high mortality rate — 47% at two years.

It is concluded that: 1) out-of-hospital ventricular fibrillation is common and treatable; 2) the phenomenon of sudden cardiac death should not be equated with acute myocardial infarction; 3) patients resuscitated from ventricular fibrillation without associated acute myocardial infarction are prone to sudden death — most likely from ventricular fibrillation.