Negative evidence in vivo of DNA-damaging, mutagenic and chromosomal effects of eugenol

The DNA-damaging, mutagenic and chromosomal effects of eugenol were assayed by the DNA alkaline elution technique, the granuloma pouch assay and the bone marrow micronucleus test in rats. With all the techniques used, eugenol did not show any genotoxic activity.

[Our ultrasonic experience in the diagnosis of traumatic lesions of the liver and spleen]

The authors on the basis of their series evaluate the accuracy of ultrasonography (US) in the diagnosis of intraperitoneal as well as hepatic and splenic intraparenchymal blood collections. Because of its reliability, lack of contraindications, feasibility at the patient's bed, easy remaking, US examination is the first choice approach to the patient with blunt abdominal trauma.

The role of arachidonic acid metabolite PGE2 on T cell proliferative response

We have examined the role of cyclooxygenase and lipooxygenase-derived metabolites of arachidonic acid (AA) during T cell activation. One of the major products of cyclooxygenase activity is prostaglandin E2 (PGE2). As is known, macrophages (Mo) are the main PGE2 producer cells among the peripheral blood mononuclear cells (PBL) and can be induced to release PGE2 during T cell activation. On culturing PBL with T cell mitogens such as phytohemagglutinin (PHA) or monoclonal antibody OKT3, the levels of PGE2 produced by Mo were positively correlated with the entity of the T cell mitogenic signal. During T cell activation, subcellular factors able to provide positive or negative signals on the Mo PGE2 production are released in culture. We observed that recombinant IL2 strongly enhanced PGE2 synthesis in lipopolysaccharide (LPS) stimulated Mo culture, while recombinant interferon gamma (IFN-gamma) partially inhibited its production. Moreover, purified IL1 induced PGE2 synthesis in resting Mo and increased its production when Mo were activated by LPS. The PGE2 released during T cell activation seems to have no effect on T cell mitogenesis, since the addition of cyclooxygenase inhibitors did not influence the proliferative response of mitogen stimulated T cells. However, the addition of PGE2 to OKT3 stimulated PBL at the beginning of the culture period inhibited the proliferative response in a dose-dependent manner. Its addition had no effect on PHA-stimulated PBL cultures. The PGE2-dependent inhibition of OKT3-induced T cell proliferation declined progressively from about 50-10% as the addition of PGE2 was delayed from 0 to 24 hr.(ABSTRACT TRUNCATED AT 250 WORDS)

[Validity of some electrocardiographic criteria in left ventricular hypertrophy]

The aim of the study was the assessment of the sensitivity, specificity and accuracy of some ECG criteria of left ventricular hypertrophy (LVH). Left ventricular mass (LVM) measured on the M-mode echogram of the left ventricle was the reference standard. Ninety-four (94) unselected, consecutive clinical patients (34 women, 60 men, average age 47 years) underwent in the same day, ECG and echocardiogram. Exclusion criteria were the presence of ischemic heart disease, atrial fibrillation and Wolff-Parkinson-White syndrome. The ECG tracings were interpreted independently by 2 investigators following 5 independent criteria of LVH: 1) Sokolow-Lyon voltage criterion (SL); 2) a modified Romhilt-Estes point score (REM); 3) left atrial abnormality (LAA); 4) left ventricular strain; 5) a new voltage criterion RaVL + SV3 corrected by sex and age. The left ventricular M-mode echograms were recorded using a left parasternal approach and were interpreted independently by 2 investigators. LVM was measured using the "Penn convention" and taking the R wave peak as end-diastole. The prevalence of LVH (= LVM 215 g) in the study population was 47%. The following results were achieved (sensitivity, specificity, accuracy): SL: 68.2%, 84%, 76.6%; REM: 63.6%, 90%, 77.7%: LAA: 36.4%, 84%, 61.7%; strain 52.3%, 72%, 62.8%; RaVL + SV3: 54.5%, 82%, 69.1%. Our data suggest: 1) the high sensitivity, specificity and accuracy of Romhilt-Estes point score are confirmed; 2) the sensitivity of Sokolow-Lyon voltage criterion is reevaluated; 3) the most sensitive morphological criterion seems to be the left ventricular strain; 4) a new voltage criterion could be useful.

Angulated transverse tomographic sections to measure cardiac dimensions by magnetic resonance imaging: a comparison with 2D-echocardiography

Magnetic resonance imaging (MRI) has shown low accuracy in measuring cardiac dimensions in normal subjects, when transverse tomographic sections are used in comparison with 2D-echocardiography. The rationale of this study was to compare cardiac dimensions in 19 volunteers based on angulated (30 degrees caudo-cranial) transverse tomographic sections both in MRI and 2D-echo. Since the planes investigated by both techniques are superimposable, highly significant correlated Ao, LA, IVS, LW, LV, and RV dimensions are observed. Standardized MRI tomography permits reduction of total examination time and assures repeatability. Thus, using the method reported here, cardiac dimensions in humans might be obtained accurately by MRI.

The expression of functional IL-2 receptor on activated macrophages depends on the stimulus applied

Human peripheral blood monocytes (Mo) synthesize prostaglandin E2 (PGE2) when activated with lipopolysaccharide (LPS). This production is strongly enhanced by the addition of supernatant from phytohaemagglutinin (PHA)-activated T cells. To evaluate the factor(s) responsible for this enhancement we studied the effect of several cytokines on the PGE2 metabolism. Recombinant interleukin-1 (IL-1) or recombinant IL-2 strongly enhanced PGE2 synthesis in LPS-stimulated Mo cultures, whereas recombinant interferon-gamma (IFN-gamma) partially inhibited its production. To see whether the effect of IL-2 on Mo was due to the presence of IL-2 receptor (IL-2R) on the cell surface, flow cytometric analysis and electron microscopy were used to investigate IL-2R expression in unstimulated and stimulated Mo. Stimulated, but not resting, Mo displayed the p55 IL-2R chain on their cellular surface and associated with the polyribosomes of the rough endoplasmic reticulum in the cytoplasm. This finding strongly suggested that the p55 chain of the IL-2R was synthesized by activated Mo. To confirm this result, 125I-labelled IL-2 was bound under high- and low-affinity conditions and cross-linked to Mo cultured in the presence of LPS, IFN-gamma or IL-1. The cross-linked 125I-IL-2/IL-2R complexes were analysed by SDS-PAGE. Mo cultured with LPS, IFN-gamma and IL-1 expressed the p55 protein detected by low-affinity cross-linking, whereas only LPS-stimulated Mo displayed a barely detectable band with an apparent MW of 70,000 under high-affinity binding conditions. In addition, stimulated Mo were found capable of producing the soluble form of IL-2R. Finally, LPS-activated Mo only responded to the addition of IL-2 by an increase in PGE2 production, suggesting that the function of IL-2R on activated Mo is linked to the stimulus applied.

Cellular basis of wall remodeling in long-term pressure overload-induced right ventricular hypertrophy in rats

To determine the effects of long-term pressure overload on the structural mechanisms implicated in wall remodeling of the right ventricle, a mild pulmonary artery banding was applied to rats approximately 2 months old, and the animals were killed 150 days later. The surgical procedure resulted in a 60% reduction in the cross-sectional area of the constricted vessel and a 52% increase in the weight of the right ventricle. The hypertrophic myocardial response was associated with an elevation in right ventricular systolic pressure (from 33 +/- 11 mm Hg to 71 +/- 12 mm Hg), right ventricular end-diastolic pressure (from 3 +/- 1 mm Hg to 10 +/- 3 mm Hg), and central venous pressure (from 2 +/- 0.2 mm Hg to 10 +/- 3 mm Hg). The 76% increase in wall thickness after pulmonary artery stenosis was the result of a 24% lateral expansion of cardiac muscle cells and a 44% increase in the number of myocytes across the ventricular wall. The intermyocyte distance was also increased by 22%. These cellular adaptations occurred with no alterations in total myocyte length, average sarcomere length, and volume composition of the myocardium. Ventricular wall area was decreased by 14%, which suggests a small reduction in chamber volume. Myocyte growth was accompanied by proportional expansions of mitochondrial and myofibrillar components, so that the ratio of mitochondria to myofibrils in the cytoplasm remained essentially constant. In conclusion, ventricular remodeling in this model of chronic pressure hypertrophy is characterized by increases in cellular diameter and number that would both tend to decrease the magnitude of systolic and diastolic stresses on a per cell basis and thus improve the myocardial response to a prolonged and sustained mechanical load.

[MacLeod's syndrome. Observations on 6 cases]

Mac Leod's syndrome is a rarely diagnosed disease; that is why an accurate differential diagnosis is needed by means of radiological imaging. This paper is aimed at discussing the differential diagnosis, with a special emphasis on the pathogenesis of the syndrome. The phenomenon of air trapping in absence of central bronchial lesions is a typical radiographic finding. Chest X-ray is performed in both inspiration and expiration. Posterior oblique tomography at 55 degrees of the affected side is also performed. Diffuse bronchiolitis obliterans in infancy or early childhood is a widely accepted pathogenetic pattern. Pulmonary hypoventilation causes vasoconstriction and underdevelopment of pulmonary vessels, that are reduced in caliber. Differential diagnosis includes all the diseases resulting in pulmonary hyperlucency, i.e. pulmonary and pleural alterations, and skeletal anomalies.

[Beta 2 microglobulin in the diagnosis of reflux nephropathy in childhood]

The authors determined beta 2 microglobulin plasmatic and urinary levels in 35 children aged 1 month-14 years; 25 of them were suffering from reflux nephropathy. The results of this study indicate that B2 microglobulin concentrations in plasma and urine can be useful parameters to the clinical diagnosis and evaluation of severity of reflux nephropathy. In presence of reduced glomerular filtration rate B2 microglobulin plasmatic levels resulted significantly out of the normal range (mean = 3318; s.d. = 1184) and proportional to the residual functionality degree (p 0.005); blood B2 microglobulin values demonstrated a higher specificity (76.2%) than creatine clearance. Moreover Bt (B2 microglobulin urinary level), Bs (B2 microglobulin excretion per minute corrected to surface area) and Bf (B- microglobulin excretory fraction) were shown to vary (p 0.025) in relation to the presence and the degree of tubulo-interstitial damage. In particular, Bf values progressively impairing with the severity of the nephropathy, were shown to have a statistically good distribution and the best sensibility (95.2%) and specificity (77.8%) in detecting tubular damage.

Hyperplasia of myocyte nuclei in long-term cardiac hypertrophy in rats

In contrast to observations made in the human heart, hyperplasia of myocyte nuclei has never been demonstrated in experimental cardiac hypertrophy. To test the hypothesis that the duration of the mechanical load more than the magnitude of ventricular hypertrophy may be the inciting stimulus for myocyte nuclei hyperplasia, constriction of the pulmonary artery was produced in rats and the hearts were examined 6 mo later. A 76% increase in right ventricular weight was measured. This hypertrophic response was accompanied by a 41% increase in the total number of myocyte nuclei in the ventricle. Furthermore, average myocyte cell volume per nucleus increased by 28%. No changes in weight, myocyte size, and nuclear number were observed in the left ventricle. In conclusion, myocyte nuclear hyperplasia and cellular hypertrophy both participate to the adaptive response of the right ventricular myocardium in long-standing pressure overload cardiac hypertrophy.

First-trimester prenatal diagnosis of Sanfilippo C disease

At 10 weeks' gestation, chorionic villus biopsy was obtained from a woman at risk for Sanfilippo type C disease. Acetyl-CoA: alpha-glucosaminide N-acetyltransferase activity was markedly deficient. The pregnancy was terminated at 12 weeks' gestation and follow-up study on fetal fibroblasts confirmed the diagnosis.

Increased incidence of isoproterenol-induced ventricular fibrillation in aging rats

Prolonged beta-adrenergic stimulation obtained by subcutaneous injection of isoproterenol in unanesthetized, unrestrained rats elicited ventricular fibrillation in approximately 80% of animals at 10-12 months of age. Ventricular fibrillation failed to occur in 1-month-old rats and involved only 12% of rats at 2 months. Senescence appeared not to increase the frequency of ventricular fibrillation since a similar incidence was seen in rats at 10-12 and 19-21 months. In all instances, ventricular fibrillation was preceded by ECG changes consistent with acute subendocardial ischemia. To evaluate whether acute beta-adrenergic stimulation elicits comparable cardiovascular effects in animals of different age, a dose-response curve to intravenous injection of isoproterenol was performed in anesthetized rats. Changes in heart rate, systemic arterial pressure, left ventricular pressure, and dP/dt were not different among animal groups. It was concluded that the arrhythmogenic potential of isoproterenol may not be related to differences in cardiac beta-receptor sensitivity with age as suggested by the comparable changes in the inotropic and chronotropic actions of isoproterenol in the animal groups studied.

Effects of exercise on the capillary vasculature of the rat heart

Effects on the myocardium, particularly those structural properties of the capillary network relevant to tissue oxygenation, were studied morphometrically in rats subjected to moderate exercise, strenuous exercise, and strenuous exercise preceded by a preconditioning period of moderate exercise. These different modalities of exercise were used to test the hypothesis that endurance training leads to capillary proliferation in the heart. The findings indicate that treadmill running produces right ventricular hypertrophy exclusively, which is accompanied by lengthening of the myocytes. Furthermore, a moderate running program results in an increase in the numerical density, luminal surface, and total length of capillaries in the right ventricle. In contrast, strenuous exercise with or without a preconditioning period produces a relative decrease in capillary luminal volume, surface, and numerical density. In the former case the diffusion distance for oxygen is decreased and in the latter it is increased. These data suggest that moderate exercise affects the microvasculature in ways that improve the efficiency of tissue oxygenation in the myocardium, whereas strenuous exercise has the opposite effect.

Response of the border zone to myocardial infarction in rats

The response of the surviving myocardium 30 days after coronary artery occlusion was measured morphometrically in the regions bordering and remote from infarcts of different sizes. Mean cell volume per nucleus increased with infarct size in both zones, but the rate of change was greater in the border than in the remote portion of the unaffected myocardium. Capillary numerical density within the uninjured tissue progressively decreased with infarct size leading to an increased diffusion distance for oxygen. Although the magnitude of changes in capillary density was similar in the two regions of the ventricle, the analysis of the individual values in each heart showed that in infarcts comprising more than 11% of the ventricular wall capillary concentration and the path length for oxygen supply to the myocytes were affected more in the border zone than in the myocardium remote from the scar. In conclusion, the border zone participates in the hypertrophic recovery process after infarction, but the inadequate growth of the capillary microvasculature suggests that this region is more susceptible to additional ischemic episodes.

Myocyte cell loss and myocyte hypertrophy in the aging rat heart

To determine the effects of age on the myocardium, the functional and structural characteristics of the heart were studied in rats at 3, 10 to 12 and 19 to 21 months of age. Systemic arterial pressure, left ventricular pressure and its first derivative (dP/dt) and heart rate were comparable in the three animal groups. In the interval between 3 and 10 to 12 months, mean myocyte cell volume per nucleus increased 53 and 26% in the left and the right ventricle, respectively. The total number of myocyte nuclei remained constant in either ventricle. In the following period, between 10 to 12 and 19 to 21 months, a 39% further cellular hypertrophy on the left side of the heart was found in association with an 18% loss of cells in the ventricle. Cell loss was accompanied by discrete areas of interstitial and replacement fibrosis in the subendocardium. In contrast, no myocardial damage was observed in the right ventricle, and the measured 35% additional enlargement of myocytes occurred without a change in cell number. Thus, the aging left ventricle is composed of a smaller number of hypertrophied cells. Cellular hypertrophy may explain the unaltered cardiac function of the aged myocardium.

Quantitative structural analysis of the myocardium during physiologic growth and induced cardiac hypertrophy: a review

The quantitative structural properties of the ventricular myocardium during postnatal physiologic growth are compared with those accompanying an increased load in the adult rat heart to determine whether induced cardiac hypertrophy is a pathologic condition or simply a form of well compensated accelerated growth. The expansion of the ventricular myocardium during maturation shows a remarkable degree of well balanced compensatory response, because the capillary microvasculature, parenchymal cells and subcellular components of myocytes all grow in proportion to the increase in cardiac mass. In contrast, the increases in myocyte diameter and length caused by pressure hypertrophy, volume hypertrophy and infarction-induced hypertrophy are consistent with concentric, eccentric and a combination of concentric and eccentric hypertrophic growth of the whole ventricle, respectively. These cellular shape changes may represent a compensatory response of the myocardium at the cellular level of organization that tends to minimize the effects of an increased pressure or volume load, or both, on the heart. Cardiac hypertrophy, however, may also show alterations affecting capillary luminal volume and surface and the mitochondrial to myofibril volume ratio, which indicate an inadequate growth adaptation of the component structures responsible for tissue oxygenation and energy production. Thus, hypertrophy of the adult heart differs from that during physiologic growth, and the hypertrophied myocardium may exhibit structural abnormalities that can be expected to increase its vulnerability to ischemia.

Coronary capillaries during normal and pathological growth

The adaptive capacity of the myocardium with respect to its capillary concentration and distribution has been measured morphometrically during the hypertrophic growth occurring physologically after birth and as a result of induced overload in the adult. In particular, the growth of the capillary network of the left ventricle was examined in rats from one to 150 days of age and in rats with spontaneous hypertension, aortic stenosis, two-kidney one-clip renal hypertension and myocardial infarction. The following quantitative structural parameters of the capillary microvasculature were analyzed: 1. Capillary luminal volume density; 2. Capillary luminal surface density; 3. The average diffusion distance for oxygen; and 4. The aggregate capillary length in the whole ventricle. The major conclusions of the present study are: 1. The postnatal growth of the heart is characterized by lengthening of the whole capillary network that is linearly related to the aging process; 2. The rate of capillary proliferation, measured by changes in capillary density, is greater in the first month of age; 3. In contrast to postnatal development, lengthening of the capillary microvasculature is not a consistent adaptive mechanism of induced cardiac hypertrophy; 4. Capillary luminal volume and surface densities and the diffusion distance for oxygen are essentially maintained in spontaneous, mechanical and renal hypertension; and 5. Cardiac hypertrophy in acute and healed myocardial infarction results in alterations of the capillary properties implicated in tissue oxygenation that may constitute the morphological counterpart of the greater vulnerability to ischemic episodes of the hypertrophied myocardium after infarction.

Humoral inhibition of neutrophil chemotaxis in Crohn's disease

In patients with Crohn's disease (CD) we investigated the C3 conversion of zymosan-activated serum (ZAS) and looked for the occurrence of chemotactic factor inactivation (CFI). We also studied the cell-directed inhibitory effect (CDI) of the CD patients' plasma and, in the same group, complement activation and complement-mediated deactivation. The mean value of ZAS C3 conversion in CD was no different from that of healthy controls, but in steroid-treated patients it was lower than in untreated CD. CFI occurred in 1 of the 23 CD sera tested, and CDI was observed in 6 out of the 22 patients tested. EDTA C3 conversion was present in 12 patients, and complement-mediated deactivation was associated with high values of EDTA C3 conversion. Our findings indicate that complement dysfunction and inhibitory factors of neutrophil chemotaxis are present in CD. These findings could explain the defective neutrophil migration into skin windows. Whether they are relevant to the pathogenesis of tissue injury or of infectious complications and are specific for CD, however, remains to be established.

[Extension of necrosis and left ventricular function in recent myocardial infarct. Correlation between a QRS scoring system and various echocardiographic indexes]

The purpose of this study was to evaluate the extension of myocardial necrosis and the impairment of left ventricular function in patients with recent myocardial infarction by means of the standard 12-lead ECG. Then, we tried to correlate the QRS scoring system proposed by Wagner and coll. with some indexes obtained from a M-Mode and Two-Dimensional echocardiographic examination (echo-score, number of compromised areas, E-septum separation and left ventricular ejection fraction) in a group of 105 pts. (mean age 61.54 +/- 9.66 SD years). Patients were divided into three groups: 47 with anterior infarction, 45 with inferior infarction and 13 with anterior and inferior infarction. A statistically significant correlation was found between the QRS scoring system and (a) the infarct size (r between ECG-score and echo-score = 0.40, p less than 0.001; r between ECG-score and compromised areas = 0.47, p less than 0.001) and (b) left ventricular ejection fraction (r = -0.48, p less than 0.001), measured echocardiographically, particularly in pts. with anterior infarction. No correlation was found with the E-septum separation. In conclusion, the correlation between QRS scoring system and echo indexes appeared statistically significant, even if minimally applicable to single cases.

Primary intracranial lymphomas

We reviewed the cases of 16 patients with primary intracranial lymphomas. The clinical and radiological data proved to be helpful in suggesting the diagnosis, but only tumoral biopsy provided unequivocal diagnosis. In our cases radiotherapy proved to be the most effective treatment.

[Rhabdomyoma of the interventricular septum in a one-day-old newborn infant. Echocardiographic diagnosis]

A case of interventricular septal rhabdomyoma in a one day-old newborn is presented. The newborn was moderately cyanosed. A 3/6 systolic murmur in basal area was present. An electrocardiogram showed the features of Wolff-Parkinson-White syndrome. A chest x-ray showed distinct cardiomegaly. M-Mode (MME) and Two-dimensional echocardiography (2DE) identified an interventricular septal mass within left ventricle and suggested the presence of left ventricular outflow obstruction. We emphasize the usefulness of MME and 2DE in accurately diagnosing intramural ventricular tumors in newborns.

Genotoxic effects in rodents given high oral doses of ranitidine and sodium nitrite

The possible intragastric nitrosation of ranitidine to genotoxic derivatives has been investigated in rats and mice given, by gavage, high single doses of this histamine H2 receptor antagonist along with NaNO2. Liver DNA fragmentation, as revealed in rats by both DNA alkaline elution and DNA alkaline denaturation followed by hydroxylapatite chromatography, was found to be dependent either on the molar ratio drug/nitrite or on the gastric pH. It occurred only with doses of 175 mg/kg ranitidine HCl + 80 mg/kg NaNO2 (molar ratio 1:2.32) or 350 mg/kg ranitidine HCl + 80 mg/kg NaNO2 (molar ratio 1:1.16) and concurrent reduction of gastric pH from 5.5 to 2-3 (produced by prolonged fasting). A further reduction of pH elicited by histamine injection increased the amount of DNA damage. DNA fragmentation in gastric mucosa showed a similar dependence on both pH and ranitidine/NaNO2 ratio, but was more marked than in liver. Simultaneous administration of ascorbic acid reduced the damage of gastric DNA. Oral administration of 175 mg/kg ranitidine HCl + 80 mg/kg NaNO2 in fasted and histamine-injected mice induced a modest but statistically significant increase in the frequency of sister chromatid exchanges in bone marrow cells.

Malaria in the emergency department

Eleven patients with malaria seen over five years in one emergency department demonstrate a trend toward more efficient diagnosis and outpatient treatment. Ten patients were diagnosed using a routine Wright's stained peripheral blood smear (three fortuitously). Because treatment of hospitalized patients consists of no more than oral chloroquine, the current regimen allows for outpatient management. Determination of species and extent of drug resistance, as well as eradication of Plasmodium vivax and P ovale, are referred to a consultant after 2 days of oral chloroquine therapy.

A boy with ring chromosome 15 derived from a t(15q;15q) Robertsonian translocation in the mother: cytogenetic and biochemical findings

We describe a boy with a ring chromosome 15, showing the manifestations characteristic of this condition, ie, growth deficiency and unusual facial appearance with minor anomalies. The ring was derived from a t(15q;15q) chromosome of the mother, who had also had four spontaneous abortions. The respective karyotypes were 45,XX, -15,-15,+t(15q;15q) (mother) and 46,XY,-15,+r(15q;15q)mat (15q13 leads to cen leads to 15q26)(son). The ring chromosome lacked the short arms of the two translocated chromosomes 15 and was duplicated for a portion of the long arms near the centromere, probably cen leads to q13. Data from enzyme assays suggest that this duplicated region carries the alpha-mannosidase gene.

Absence of DNA damage in liver of rats given high doses of cimetidine and sodium nitrite

A correlation between cimetidine and gastric cancer has been suggested. Nitrosation of cimetidine in the presence of nitrite and HCl and mutagenic activity as well as DNA damage in mammalian cells displayed by nitrosocimetidine, as these phenomena occur in vitro, were the supporting hypothesis. Previous studies have shown that liver DNA damage was a well correlated index of potential carcinogenic activity of N-nitroso compounds and that such a damage was found after long-term simultaneous oral administration of aminopyrine and nitrite in rats. In this work, liver DNA fragmentation was investigated by three different techniques: DNA alkaline elution, DNA alkaline denaturation followed by hydroxylapatite chromatography and a new viscometric method markedly more sensitive than the above mentioned ones in detecting DNA damage. Evidence of DNA damage was not gained in any of the groups of rats treated with high single or successive oral daily doses of cimetidine (250 mg/kg) along with nitrite (80 mg/kg) in approximately equimolar amounts. Cimetidine and nitrite given alone were also ineffective. The lowering of gastric pH, obtained with fasting and histamine administration before giving cimetidine and nitrite combination in a single dose, did not favor the induction of liver DNA fragmentation neither in the above condition nor even when the amount of cimetidine was lowered to 125 mg/kg in order to obtain an approximately 2-fold molar amount of nitrite.

Cleavage of the (1 goes to 3)-2-acetamido-2-deoxy-beta-D-glucopyranosyl linkage present in keratan sulfate. The A and B isoenzymes of human liver hexosaminidase (EC 3.2.1.30)

The disaccharide 2-acetamido-2-deoxy-beta-D-glucopyranosyl-(1 goes to 3)-D-[1-3H]-galactitol, prepared from keratan sulfate, was rapidly hydrolyzed by the A and B isoenzymes of normal human liver hexosaminidase (EC 3.2.1.30), and by the B isoenzyme prepared from the liver of a patient who had died of Tay-Sachs disease. The disaccharide substrate was also hydrolyzed by extracts of normal, cultured-skin fibroblasts, and fibroblasts of patients with Tay-Sachs disease, whereas it was not hydrolyzed by fibroblast extracts of patients with Sandhoff disease. Thus, effective degradation of keratan sulfate, secondary to a defect of the beta subunits present in the A and B isoenzymes of hexosaminidase, may contribute to the appearance of skeletal lesions in patients affected by Sandhoff disease.

In vitro studies on cellular and humoral chemotaxis in Crohn's disease using the under agarose gel technique

The locomotor function of polymorphonuclear cells (cellular chemotaxis) and serum chemotactic activity (humoral chemotaxis) were studied in 51 patients with Crohn's disease using a method of migration under agarose gel. To study cellular chemotaxis patient's polymorphonuclear cells were challenged against normal Zymosan activated serum and humoral chemotaxis was evaluated testing the patient's Zymosan activated serum against normal polymorphonuclear cells. Cellular chemotaxis in the Crohn's disease group was normal (although 30% of the 51 patients had migration values out of the normal range), while humoral chemotaxis was significantly lower in Crohn's disease patients than in the control group. However, the value of humoral chemotaxis in the group of Crohn's disease patients treated with steroids was lower than that of patients not treated, thus accounting for the low mean value observed inthe Crohn's disease-group as a whole. The present results suggest that a defective chemotactic response may occur in some Crohn's disease patients, particularly during steroid treatment. These findings might be related either to a defective generation of complement derived chemotactic factors or to the presence of circulating inhibitors.

Ultrastructural studies of type II fucosidosis

Type II fucosidosis in an autosomal recessive disease. The paper presents a case of a patient with alpha-L-fucosidase of whom a skin specimen was examined under the electron microscope. Storage material was observed mainly in endothelial cells of blood capillaries and Schwann cells surrounding small peripheral nerves of papillary dermis. Within both cells two different kinds of inclusions were revealed: (1) clear vacuoles and (2) dense bodies with an internal structure prevalently lamellar. All these ultrastructural alterations were observed long before the appearance of clinically defined angiokeratoma at cutaneous level. Hence, they present the same alteration found in the absence of angiokeratoma in type I fucosidosis.

New evidence of circulating immune complexes in Crohn's disease using two sensitive methods

Circulating immune complexes (AgAb) were studied in 183 serum samples from 119 patients with Crohn's Disease. AgAb were studied by the solid phase C1q binding test in all sera and also by the conglutinin binding assay in 161 sera. A significantly higher prevalence of circulating AgAb was observed in Crohn's disease patients in comparison with the control population. About one half of the sera were AgAb positive when the results of both tests were combined whereas AgAb were found in about one third of the sera by each individual method. Complexes revealed by the C1q-SP appeared to be related to the disease activity and to the occurrence of complications. Such a correlation was not observed as far as conglutinin results are concerned. Data emerging from the present investigation indicate that circulating AgAb may be present in Crohn's disease and suggest that the AgAb material is heterogeneous. They also suggest the possibility that AgAb represent a secondary phenomenon.

[The effect of althesin anesthesia on atrioventricular conduction]

A study of one of the several factors influencing operative risk was made by studying the effects of Althesin on the conduction system by recording the His potentials in 8 patients.