Cardiolipin packing ability studied by grazing incidence X-ray diffraction.

We report a grazing incidence X-ray diffraction (GIXD) study of pure and mixed Langmuir monolayers of tetramyristoyl cardiolipin (TMCL) and dipalmitoylphosphatidylcholine (DPPC) at 22 degrees C. The mixing behavior of the two components was investigated at two different surface pressures, 4 and 25mNm(-1). Cardiolipins are found to be in a liquid-condensed (LC) phase at 4mNm(-1) whereas the DPPC molecules appear disordered. At 25mNm(-1), cardiolipins are in a solid phase with their aliphatic chains perpendicular to the interface whereas the DPPC molecules are in the LC phase. At this surface pressure, increasing the amounts of TMCL to DPPC leads to a reduction in tilt angle of the aliphatic chains from nearly 30 degrees for pure DPPC to almost 0 degrees in a 1:1 molar ratio of DPPC and TMCL. At this composition, we also found the closest packing of the aliphatic chains. Further increase of the amount of TMCL does not change the lattice or the tilt and the thermodynamic analysis confirms a partial phase separation. Such a behavior was not observed at 4mNm(-1) where the two phospholipids are miscible at all the compositions studied. Addition of TMCL clearly induces a structuring of the mixed monolayers and increases order by a tight packing in the lipid acyl chains.

Lasalocid and biomimetic membranes: insertion in Langmuir films of lipids.

The interfacial properties at the water surface of dipalmitoylphosphatidylcholine (DPPC) in monomolecular films containing various concentrations of lasalocid sodium salt (LAS) have been studied in the range from r = 0.005 to 0.1 (r = molar ratio LAS:DPPC). The data from which the results have been expressed were obtained from the following compression isotherms at constant temperature (22 degrees C): of mixed films, of pure DPPC and of pure LAS. The incorporation of LAS resulted in pressure and concentration dependent molecular area increase, between 0 and 16 mN m-1. The observed effect has been expressed as the area SA* occupied by each antibiotic molecule in the mixed films. The variations of SA* have been discussed at two levels of constant surface pressure, at 8 mN m-1 which is situated in the phase transition region of the DPPC isotherm and at 4 mN m-1 in the liquid expanded state. In both cases, the SA* values decreased as r increased. They have been related to the molar areas SA of LAS, obtained from the compression isotherm of the pure antibiotic and expressed as SA*/SA. This ratio was considerably greater than unity in the phase transition region within the studied concentration range and close to unity in the liquid expanded state. Using the method of Goodrich, the excess free energy of mixing GXS has been calculated. The values were positive above r = 0.01 and they increased with increasing concentrations. The results indicate non miscibility and strong repulsion between the two kinds of molecules in the mixed films. Two different mechanisms of insertion have been suggested.

Interactions of lipid monolayers with the natural biopolymer hyaluronic acid.

The interaction of the natural mucopolysaccharide hyaluronic acid with different lipids, present in the natural membranes, was studied at the lipid/water interface using thermodynamic methods and X-ray diffraction. The results show that this biopolymer modifies the properties and the structure of the lipid monolayer. The two-dimensional crystalline lattice and domain structure of the charged octadecylamine monolayer are strongly disturbed by the hyaluronic acid, the monolayer compressibility increases and the monolayer collapse pressure drops down. In addition, the presence of charged lipid interfaces influences the structural organisation of the hyaluronic acid at the membrane/water interfaces. The impacts of these results on the structural organisation at the membrane interface are discussed.

[Normal pancreas aspects. Variations and malformations]. / Aspects du pancréas normal. Variantes et malformations.

Major advances have occurred with regards to imaging of the pancreas. In spite of harmonic imaging, US remains limited. Multi-detector CT allows excellent evaluation of the pancreatic parenchyma with multiplanar ductal and vascular reformations. MRI provides excellent evaluation of the pancreatic parenchyma using fat suppressed T1W images and excellent evaluation of the biliary tract and pancreatic duct using T2W images. Senile pancreas is characterized by atrophy and ductal dilatation, sometimes microcystic. Fatty infiltration of the pancreas could be focal or diffuse. Pancreas divisum is characterized by the absence of fusion of the pancreatic ducts with several anatomic variants. Annular pancreas results from malrotation of the pancreatic buds. MRI is the best technique to diagnose these malformations.

The patients with incidentally discovered adrenal adenoma (incidentaloma) are not at increased risk of osteoporosis.

The main problem in the management of the patients with incidentally discovered adrenal mass (incidentaloma) is whether and when the incidental mass puts the patient at increased risk for an adverse outcome. As osteoporosis is a well known complication of endogenous and exogenous glucocorticoid excess, it is likely that patients with incidentally discovered adrenocortical adenomas have impaired bone mass due to subclinical hypercortisolism. We measured spinal bone mineral density (BMD) by dual energy x-ray absorptiometry in 27 patients (9 men and 18 women) and 54 healthy subjects (18 men and 36 women) carefully matched for age, sex, body mass index, and menstrual status for a case-control analysis. BMD was also measured at the hip in the group of patients. A multiple regression analysis was performed to determine which biochemical variables might influence BMD values. Lumbar BMD values in patients with adrenal incidentaloma were not significantly different from those in control subjects (BMD, 0.926, 0.604--1.144 vs. 0.936, 0.645--1.268 g/cm(2); P = NS). No significant difference in lumbar and femoral BMD was found between patients with or without subclinical Cushing's syndrome. Among the variables processed, only PTH remained in the final model and was inversely correlated with lumbar spine and femoral neck BMD values (r = -0.5; r(2) = 0.25; P = 0.015 and r = -0.42; r(2) = 0.18; P = 0.03, respectively). In conclusion, our data do not suggest that the slight glucocorticoid excess associated with adrenal incidentaloma increases the risk of osteoporosis. The evaluation of BMD does not seem to be crucial in the management of incidentally discovered adrenal masses.

Growth hormone (GH) responses to GH-releasing hormone alone or combined with arginine in patients with adrenal incidentaloma: evidence for enhanced somatostatinergic tone.

Spontaneous and stimulated GH secretion is blunted in hypercortisolemic states due to increased hypothalamic somatostatinergic tone. However, no data are available on the characteristics of GH secretion in patients with incidentally discovered adrenal adenomas. They represent an interesting model for studying GH secretion, as a slight degree of cortisol excess may frequently be observed in such patients who do not present with any clear Cushingoid sign. In the present study, 10 patients (3 men and 7 women, aged 48-63 yr) with an adrenal mass discovered serendipitously underwent, on separate occasions, a GHRH injection alone or combined with an infusion of the functional somatostatin antagonist, arginine. Thirteen age-matched healthy volunteers served as controls. Briefly, arginine (30 g) was infused from -30 to 0 min, and GHRH (100 microg) was injected as a bolus at 0 min, with measurement of serum GH [immunoradiometric assay (IRMA)] every 15 min for 150 min. Plasma IGF-I (RIA after acid-ethanol extraction) was measured in a morning sample. The diagnosis of cortical adenoma was based on computed tomography features and pattern of uptake on adrenal scintigraphy. Patients with obesity and/or diabetes were excluded. The study design included also an endocrine work-up aimed to study the hypothalamic-pituitary-adrenal axis [urinary free cortisol (UFC) excretion, serum cortisol at 0800 h, plasma ACTH at 0800 h, morning cortisol after overnight 1 mg dexamethasone]. Five of 10 patients showed abnormalities of the hypothalamic-pituitary-adrenal axis, including borderline or increased UFC excretion in 4 of them accompanied by blunted ACTH in 2 cases and failure of cortisol to suppress after dexamethasone in 1; the fifth patient displayed low ACTH and resistance to dexamethasone suppression. However, all patients had a unilateral uptake of the tracer on the side of the mass with suppression of the contralateral normal adrenal gland. As a group, the patients displayed greater UFC excretion and lower ACTH concentrations than the controls. GH release after GHRH treatment was blunted in patients bearing adrenal incidentaloma compared with controls (GH peak, 5.7 +/- 5.2 vs. 18.0 +/- 7.0 microg/L; P < 0.0001), whereas GHRH plus arginine was able to elicit a comparable response in the 2 groups (GH peak, 33.5 +/- 20.3 vs. 33.7 +/- 17.5 microg/L; P = NS). The ratio between GH peaks after GHRH plus arginine and after GHRH plus saline was significantly greater in patients than in controls (751 +/- 531% vs. 81 +/- 45%; P = 0.0001). Similar data were obtained when comparing GH area under the curve after GHRH plus saline or GHRH plus arginine between the 2 groups. In summary, the present data suggest that in patients with incidental adrenal adenomas the GH response to GHRH is blunted due to increased somatostatinergic tone, as it can be restored to normal by pretreatment with the functional somatostatin antagonist arginine. The blunted GH release to GHRH may be an early and long lasting sign of autonomous cortisol secretion by the adrenal adenoma.

Effects of nifedipine on functional liver plasma flow in normal subjects and in patients with cirrhosis.

The short-term effects of nifedipine (10 mg administered sublingually) on functional liver plasma flow, measured by calculating the extrarenal clearance of sorbitol, were investigated in 12 normal volunteers and 40 patients with cirrhosis scored according to Child-Pugh classification. Nifedipine significantly increased functional liver plasma flow in healthy subjects (23%, p < 0.0001) and in patients with cirrhosis in the Child-Pugh class A group (19%, p < 0.001); in patients in the Child-Pugh class B group functional liver plasma flow was not modified, whereas in the patients in the Child-Pugh class C group it was significantly reduced (-7%, p < 0.02). The mean arterial pressure showed a significant reduction in all groups studied. According to the pathophysiologic meaning of functional liver plasma flow, it is suggested that nifedipine meets criteria for an ideal test substance to evaluate the functional reserve of the liver. Furthermore, when used with the Child-Pugh classification, its effect on functional liver plasma flow may be useful to improve the efficiency of the Child-Pugh classification, in establishing the prognosis of patients with cirrhosis.

The value of dehydroepiandrosterone sulfate measurement in the differentiation between benign and malignant adrenal masses.

OBJECTIVE: Owing to their increasing rate of discovery as incidental findings, the characterization of adrenal masses is an important diagnostic problem which frequently challenges the clinician's skill. DESIGN: The results of dehydroepiandrosterone sulfate (DHEAS) measurement were evaluated in a consecutive series of 107 patients with an adrenal mass (39 men, 68 women aged 15-81 years, median 56 years). DHEAS levels observed in the patients were categorized as reduced, normal or elevated according to sex- and age-adjusted reference ranges obtained by measuring DHEAS in 214 healthy women and 142 healthy men aged 17-93 years. The working hypothesis was that a low DHEAS level is a marker of benignity. METHODS: In 84 patients, the adrenal mass was discovered serendipitously, while in the remainder the mass was clinically symptomatic. Patients with known extra-adrenal malignancies were excluded. The adrenal masses were categorized as benign or malignant by computerized tomography (CT) criteria. All patients with suspected malignant tumors or with overtly hypersecreting tumors underwent adrenalectomy. The patients with a presumptive benign tumor were followed-up for at least 12 months. RESULTS: In the overall series, the sensitivity and specificity of a low DHEAS level in the identification of a benign lesion were 41% and 100% respectively. Superimposable figures were obtained when considering only adrenal incidentalomas. DHEAS levels in adrenal cancers displayed some overlap with adrenal adenomas, but in only 2/11 adrenal cancers were DHEAS levels normal, while they were elevated in the remainder. CONCLUSIONS: The present data suggest that DHEAS measurement may help to differentiate benign from malignant adrenal masses as a complementary test of CT in a clinical research setting. The value of DHEAS measurement in general practice is limited because it may be difficult to differentiate between low and low-normal values, particularly in the elderly.

Assessment of functional liver mass and plasma flow in acromegaly before and after long-term treatment with octreotide.

Functional liver mass and functional liver plasma flow (FLPF) were assessed in 11 patients with clinical features of acromegaly by determining galactose elimination capacity (GEC) and extrarenal clearance of sorbitol, before and 5 to 7 months after treatment with the long-acting somatostatin analog, octreotide (150 to 600 micrograms/d in three subcutaneous injections). Growth hormone (GH) and insulin-like growth factor-I (IGF-I) levels, as well as liver size by ultrasound, were also recorded. Baseline GEC was increased in every patient but one, for a mean of 0.78 +/- 0.10 g/min (normal, 0.53 +/- 0.07; P < .01). At reevaluation after 5 to 7 months of octreotide treatment, a significant reduction of GEC was observed (0.62 +/- 0.08 g/min, P < .001). Changes of GEC paralleled those of GH (38.6 +/- 34.4 v 11.7 +/- 15.2 micrograms/L, P < .01) and IGF-I (5.0 +/- 1.7 v 2.7 +/- 2.2 U/ml, P < .001). Significant correlations were found between GEC and GH (r = .50, P < .05) and between GEC and IGF-I (r = .55, P < .01). FLPF, assessed by extrarenal clearance of sorbitol, was within the normal limit in all cases (0.98 +/- 0.19 v 0.97 +/- 0.12 L/min, NS) and remained normal after 5 to 7 months of octreotide treatment (0.99 +/- 0.11 L/min). Hepatic structure determined with ultrasonic scanning and conventional liver-function tests were basally normal in all patients, with a slight increase of liver volume in three cases. No change of biochemical and/or morphological features occurred during follow-up evaluation. The results support the hypothesis that GH and especially IGF-I enhance liver metabolic capacity; conversely, functional liver perfusion is largely independent of their actions. Our data also suggest that octreotide is unable to produce well-structured changes of liver circulation when administered long-term.

A differential scanning calorimetry study of the interaction of lasalocid antibiotic with phospholipid bilayers.

Interaction of lasalocid sodium salt (Las-Na) with dipalmitoylphosphatidylcholine (DPPC) as a membrane model was investigated by highly-sensitive differential scanning calorimetry (DSC). The insertion properties of the antibiotic were studied both in multilamellar suspensions and unilamellar vesicles, for Las-Na/DPPC molar ratios (r) ranging from 0.005 to 0.1. The effect of the antibiotic on the lipid thermotropic behavior is concentration dependent and drastically changes at a critical r of 0.04 in both model membranes. Below this ratio, Las-Na molecules interact with DPPC bilayers without disrupting the global organization of the membrane. In the multilamellar systems only the transition cooperativity is affected whereas for the mixed vesicles, a decrease in the enthalpy change suggests a different mode of insertion. Above this ratio, implantation of the antibiotic give rise to lateral phase separation in multilamellar systems. These structural modifications have repercussions on the formation of mixed LAS-Na/DPPC vesicles which seems limited to an r value of 0.04.

Elderly-animal postmortem attachment.

Attachment can be strong between people and their pets. The present study was conducted to determine: (1) specific variables associated with the final rite and disposition of the deceased pet, and (2) those criteria associated with emotional and social factors pertaining to elderly-animal postmortem attachment. Results suggested four most frequently stated variables of final rite and disposition, and eight emotional and social factors of elderly-animal postmortem attachment.

Perceived self-image of escapist and throwaway runaways.

It has been estimated that several million youngsters run away from home every year in the USA. The present research was conducted to determine the extent to which the escapist and throwaway runaways perceived their self-image. It focused on variables the runaways perceived as the most significant for them regarding perception of self. Results indicated that escapists tend to perceive themselves with greater self-worth, self-confidence, and self-motivation than did the throwaways. The latter Ss tend to perceive themselves with greater self-acceptance and self-depression compared to the former group, while both S groups had no significant difference in their perceptions of self-reliance.

Emotional characteristics of chronic and acute incestuous daughters.

Incest can have a devastating effect on the emotional stability of the victim both in childhood and in adulthood. The present research was conducted to determine: (1) emotional variables associated with chronic and acute incestuous daughters, and (2) a comparison of the similarities and/or differences of each. Results suggested ten different variables of importance in father-daughter incest, however, there were significant differences regarding which of these tended to be associated more with either the chronic or acute incestuous daughters.

Experimental studies of food selective behavior in squirrel monkeys fed on riboflavin deficient diet.

A squirrel monkey, if it needs a particular dietary component because of a metabolic disorder or because that food has been excluded from its diet, will develop a specific hunger for the food. In cases where specific hungers show up clearly, four behaviors can be demonstrated: (1) The monkey prefers the food it needs to other foods that are also available; (2) It usually ingests large amounts of the food to meet its particular physiological requirements; (3) The animal will tend to eat the needed food even while the stomach is full; (4) When vitamin B2 is removed from its diet, a squirrel monkey will exhibit digestive disturbance, general weakness, a lack of vigor, and loss of weight.

[Data on a comparison between a rapid test and urine culture for the determination of bacteriuria]. / Dati comparativi fra una prova rapida e l'urocoltura per la determinazione della batteriuria.

A streep test has been employed for bacteriuria involving identification of nitrites in the urine and results are compared with those obtained with classical bacteriological techniques. Parallel performance of the nitrite test and urine culture showed that the latter cannot be replaced as far as diagnosis goes but it also proved the usefulness of the nitrite test for mass screening purposes.

[Paralysis of the common oculomotor nerve and contralateral cerebellar syndrome (Claude's syndrome). 2 cases caused by mesencephalic infarction]. / Paralysie du nerf moteur oculaire commun et hémisyndrome cérébelleux contralatéral (syndrome de Claude). Deux cas par infarctus mésencéphalique.

Two cases of Claude's syndrome due to a mesencephalic infarction in the territory of the interpedoncular fossa arteries are reported. The first case had pupillary sparing while ptosis was lacking in the second case. Partial impairment of the oculomotor nerve suggests an intra-axial fascicular organization. However, the precise intra-axial pattern of the nerve is unknown in humans.

Magnetic resonance imaging in partial epilepsy of childhood. Seventy-nine cases.

A heterogeneous series of 79 children with partial epilepsy was studied by computerized tomography (CT) and magnetic resonance imaging (MRI) to evaluate the contribution of MRI to the aetiological diagnosis of that disease. Both CT and MRI were normal in 13 cases and abnormal in 41 cases showing the same pathology (malformation, atrophy, tumour, scar). In 4 cases of continuous partial epilepsy the lesions observed were either diffuse or focal corresponding to the electrical focus, and they could be due to Rasmussen's encephalitis. In 19 cases where CT gave normal results, MRI showed bilateral high-intensity signal areas of uncertain significance in the white matter of the caudal part of the hemispheres. All considered, it seems that with its greater sensitivity MRI should be the first or only exploratory method to be used in the evaluation of partial epilepsy of childhood.

Value of MRI in the morphological evaluation of tumors of the third ventricle.

The detection or suspicion of a tumoral expansive process in the third ventricule is usually performed by MRI. The contribution of MRI to the diagnosis is unquestionable in view of its accuracy in the topographical characterization of these lesions and in the detection of small formations. The great histological variety of tumours in that region may result in different treatments which can be associated. MRI, therefore, plays an important role in pretherapeutic morphological evaluation. Fifteen patients with tumour of the third ventricle were examined by MRI before treatment. The results of these examinations were compared with the pathological data and the therapeutic procedures: ventricular shunting, stereotactic needle biopsy, radio- or chemotherapy and surgery. MRI cannot provide a formal histological characterization, but it can individualise some categories of tumours, give details on the walls of the third ventricle (notably in the case of bifocal pineal and suprassellar lesions), visualize the paths of CSF flow and predict the need for cisternoventriculostomy, and detect venous structures in the vicinity of the great cerebral vein which might result in post-biopsy and post-surgery complications.

Experimental studies on food selective behavior in squirrel monkeys fed on riboflavin deficient diet.

The present study was conducted to determine the extent to which squirrel monkeys might demonstrate self-selective behavior when fed a riboflavin deficient diet, and the extent to which such a diet might lead to digestive disturbances, general weakness, lack of vigor, and loss of weight for such animals. Ss included 12 male squirrel monkeys approximately eight months of age. Experimental Ss, fed a riboflavin deficient diet, were tested on performance on a T-maze, a "vigor roller apparatus," and observed for digestive disturbances, general weakness, and loss of weight. Control Ss, fed a balanced diet, were given the same procedure. Significant results from the .001 to the .05 levels indicated experimental S s preferred a high riboflavin diet after the diet was deficient in this substance, and indicated digestive disturbances, lack of vigor, and loss of weight as compared with the control Ss.

Graffiti and adolescent personality.

Graffiti has been studied for many years from many viewpoints. They have been used to explain accounts of people, styles of life, and assumed relationships. The present paper reports an attempt to analyze graffiti as outward manifestations of adolescent personality. Results suggested that different forms of graffiti could be interpreted from five characterizations of early adolescent personality: sexual maturity, self-identity, idealism, iconoclasm, and rebelliousness. Significant differences were found between boys and girls in numbers of inscriptions for each category. Further, the graffiti were analyzed in relation to early adolescent stages of development.