Idiopathic normal-pressure hydrocephalus in adults: Result of shunting correlated with clinical findings in 18 patients and review of the literature

The authors describe their findings in a study aimed at identifying clinical-prognostic factors in treatment of idiopathic normal-pressure hydrocephalus. The study comprised 18 adult patients submitted to surgery for ventriculo-peritoneal shunting. The findings that emerged from this series of patients were compared with those reported for the 381 published cases. In our group of 18 patients, average age was 65 years and the average duration of clinical history was 47 months (median 18 months). Follow-up ranged from 3 to 5 years (median 4.2 years): 12 patients improved (9 completely) and 6 presented stable neurological deficits. The factors that had a statistically significant influence on outcome were a short clinical history (less than 6 months) (p = 0.05) and a clinical onset without dementia (p = 0.03). Patients with medium-grade preoperative ventricular enlargement always made a complete functional recovery after surgery (p = 0.2).     

Osteosonographie der Phalangen bei M?nnern

Zusammenfassung □ Hintergrund  Die distale Metaphyse der Grundphalanx der Finger II bis V ist, genau wie der Wirbelk?rper, wegen der gleichzeitigen Pr?senz von Kompakta und Spongiosa eine geeignete Region zur Messung der Mineralisation und Struktur des Knochens. □ Methode  Mit einem Osteosonographen (DBM Sonic 1200, IGEA, Italien) ma?en wir bei 38 jungen, gesunden M?nnern 14 ?lteren gesunden M?nnern, 18 M?nnern mit Osteopenie, acht M?nnern mit Osteoporose und Wirbelk?rperfrakturen sowie an zehn M?nnern mit mindestens seit einem halben Jahr durchgeführter Glukokortikoidmedikation über der Cushing-Schwelle die amplitudenabh?ngige Ultraschallgeschwindigkeit (adSOS) und den „ultrasound bone profile score” (UBPS) an Phalangen. Des weiteren wurde die Knochendichte (BMD) an der Wirbels?ule mit der DXA-Methode (Dual-R?ntgen-Absorptiometrie) gemessen. □ Ergebnisse  Es gab keine Korrelation zwischen adSOS oder UBPS und Wirbels?ulen-BMD (DXA). Wir fanden eine signifikant positive Korrelation zwischen adSOS und UBPS, r=0,826 (p<0,00001). Die adSOS nahm mit dem Alter ab (r=−0,694, p=0,021) der UBPS war nicht altersabh?ngig (r=−0 15, p=n.s.). AdSOS und UBPS konnten gut zwischen den gesunden jungen Kontrollen und den M?nnern mit Osteopenie/Osteoporose oder Glukokortikoidmedikation unterscheiden (p<0,00001). Mittels BMD (DXA-Methode) wurden gesunde Kontrollen signifikant von den Patienten mit Osteopenie oder Osteoporose unterschieden. Bei den M?nnern mit Glukokortikoidmedikation bestand kein signifikanter Unterschied zu den Gesunden. Allein der UBPS konnte diese Gruppe signifikant von den ?lteren Gesunden unterscheiden. □ Schlu?folgerung  Diese Resultate zeigen, da? adSOS und UBPS pr?zise Parameter sind, die man an den Phalangen messen kann. Die Erfassung von pathologischen Ver?nderungen bei Osteoporose ist etwa gleichwertig bei adSOS und BMD (DXA) und kann durch den UBPS verbessert werden. Dies kann erkl?rt werden durch die frühe Erfassung struktureller Ver?nderungen im Knochen durch den UBPS. Prospektive Studien müssen nun die Wertigkeit von adSOS und UBPS im Hinblick auf die Frakturvorhersage kl?ren.      

Excitatory motor and electrical effects produced by tachykinins in the human and guinea-pig isolated ureter and guinea-pig renal pelvis

1. In isolated tissue experiments, neurokinin A (NKA) produced concentration-dependent contraction of human and guinea-pig ureter (pD₂=6.7 and 7.2, respectively); an effect greatly reduced (>80% inhibition) by the tachykinin NK₂ receptor-selective antagonist MEN 11420 (0.1 μM). The tachykinin NK₁ and NK₃ receptor agonists septide and senktide, respectively, were ineffective.
2. Electrical field stimulation (EFS) of the guinea-pig isolated renal pelvis produced an inotropic response blocked by MEN 11420 (0.01–1 μM). In the same preparation MEN 11420 (0.1 μM) blocked (apparent pK_B=8.2) the potentiation of spontaneous motor activity produced by the NK₂ receptor-selective agonist [βAla⁸]NKA(4–10).
3. In sucrose-gap experiments, EFS evoked action potentials (APs) accompanied by phasic contractions of human and guinea-pig ureter, which were unaffected by tetrodotoxin or MEN 11420 (3 μM), but were blocked by nifedipine (1–10 μM). NKA (1–3 μM) produced a slow membrane depolarization with superimposed APs and a tonic contraction with superimposed phasic contractions. NKA prolonged the duration of EFS-evoked APs and potentiated the accompanying contractions. MEN 11420 completely prevented the responses to NKA in both the human and guinea-pig ureter.
4. Nifedipine (1–10 μM) suppressed the NKA-evoked APs and phasic contractions in both human and guinea-pig ureter, and slightly reduced the membrane depolarization induced by NKA. A tonic-type contraction of the human ureter in response to NKA persisted in the presence of nifedipine.
5. In conclusion, tachykinins produce smooth muscle excitation in both human and guinea-pig ureter by stimulating receptors of the NK₂ type only. NK₂ receptor activation depolarizes the membrane to trigger the firing of APs from latent pacemakers.

     

Misalignment of lung vessels: diagnostic role of conventional histology and immunohistochemistry

Misalignment of lung vessels represents a rare congenital anomaly that may cause respiratory failure in the newborn. It is characterized by abnormal position of pulmonary veins and venules that lie adjacent to arteries and bronchi, and it is usually associated with a decreased number of alveolar capillaries (i.e., alveolar capillary dysplasia), although these two conditions have been separately described. Awareness of this anomaly is required by pathologists because it can be easily overlooked on lung biopsy or autopsy, and because definite diagnosis relies on histology. We report the case of a newborn male baby who developed respiratory distress 18 h after an uncomplicated delivery. The patient died on the 7th day, after high frequency oscillatory ventilation, nitric oxide inhalation and extracorporeal membrane oxygenation were unsuccessful. On autopsy, histology and immunohistochemistry demonstrated diffuse changes, fulfilling diagnostic criteria of misalignment of lung vessels and of alveolar capillary dysplasia in both lungs, with muscularization of very peripheral pulmonary arteries and a prominent interstitial and periadventitial fibrosis. Diffuse distribution of vessel misalignment could explain the rapid onset of respiratory failure, and the presence of diffuse fibrosis might have contributed to irreversible respiratory dysfunction by impairment of lung parenchyma extensibility.     

Postmenopausal femur bone loss: effects of a low dose hormone replacement therapy

OBJECTIVES: Previous studies indicate that low-dose hormone replacement therapy (LD-HRT) can relieve vasomotor symptoms and prevent spine bone loss. METHODS: In the present study, we evaluated the effects of a low dose of conjugated equine estrogens (CEE; 0.3 mg) associated with different progestins in continuous combined scheme [2.5 mg of medroxyprogesterone acetate (n=25), 5 mg dydrogesterone (n=27), 2.5 mg nomegestrol (n=11)] as single group, on femur bone mineral density (BMD) and bone metabolism in young postmenopausal women (相似文献   

Interhemispheric asymmetry of human sleep EEG in response to selective slow-wave sleep deprivation

Recent evidence suggests that the human sleep electroencephalogram (EEG) shows regional differences over both the sagittal and coronal planes. In the present study, in a group of 10 right-handers, the authors investigated the presence of hemispheric asymmetries in the homeostatic regulation of human sleep EEG power during and after selective slow-wave sleep (SWS) deprivation. The SWS deprivation was slightly more effective over the right hemisphere, but the left hemisphere showed a markedly larger increase of EEG power in the 1.00-24.75 Hz range during recovery-night non-REM sleep, and a larger increase of EEG power during both deprivation-night and recovery-night REM sleep. These results support the greater need for sleep recuperative processes of the left hemisphere, suggesting that local sleep regulation processes may also act during REM sleep.     

Postnatal development of rat dentate gyrus: effects of methylazoxymethanol administration.

In order to investigate the role of postnatal neurogenesis in granule cell number control in the rat dentate gyrus, we administered Methylazoxymethanol (MAM), a drug able to prevent cells from dividing, on P3, P5, P7, P9, when the most granule cells are produced. The effect of MAM on the number of proliferating precursors and of granule cells was examined at P16 and P90. We used 5-bromo-2'-deoxyuridine administration to label proliferating cells and immunohistochemistry to characterize the cell phenotype using neuron markers TUC 4, PSA-NCAM, Calbindin D28K and glial marker GFAP. At 16 days of age in MAM-treated rats we observed a significant decrease of BrdU-positive cells. Consistently, a decrease in density and number of granule cells was found compared to the controls. At 90 days the dentate gyrus of treated rats showed a complete recovery: no differences in the density, total number of neurons, the BrdU- and TUC 4-positive cells were revealed with respect to the controls. No deficits were evident in performance on the water maze in MAM-treated rats. These data suggest that the dentate gyrus is able to re-establish the proliferative zone and to rebuild the granule cell layer following neonatal MAM administration.     

Estimation of Organ Transport Function from Recirculating Indicator Dilution Curves

The transport function of an indicator through an organ allows the calculation of important physiological parameters, but its estimation, especially in the presence of recirculation, can be difficult. In this paper, we estimate the transport function of ³H-mannitol (an extracellular tracer of glucose) in the human leg skeletal muscle. To do so, an indicator bolus is administered into the femoral artery and its recirculating dilution curves are nonuniformly sampled in both the femoral artery and the femoral vein. A new deconvolution-based method is used to simultaneously estimate the indicator transport function and the organ plasma flow. Subsequently, the indicator mean transit time and distribution volume are calculated. The reliability of the method is assessed by Monte Carlo simulation. The ability to estimate parameters, like mean transit time and extracellular distribution volume, is critical to the study of pathophysiologic states such as diabetes, insulin resistance, and hypertension. © 1998 Biomedical Engineering Society. PAC98: 8710+e, 0270Lq, 8745Hw     

Spinal use-dependent plasticity of synaptic transmission in humans after a single cycling session

The spinal cord is able to express use-dependent plasticity, as demonstrated in spinalized cats following treadmill training. In humans, spinal use-dependent plasticity is inferred from modifications in the size of H reflex, which are often more prominent after skilled motor training. Plasticity can develop at synaptic connections between afferent fibres and/or descending tracts and motoneurones or interneurones interposed in the spinal pathways. Here we explore whether skilled training induces a change in synaptic efficacy at the synapse between Ia afferents and soleus (Sol) motoneurones. Synaptic efficacy can be modulated presynaptically through changes of the probability of transmitter release (homosynaptic depression, HD). The frequency-related depression of the Sol H reflex, thought to reflect HD, was tested at rest, before and after one single skilled (14 subjects) or non-skilled (9 subjects) cycling training session. Performance improved in both groups but to a larger extent with skilled training, while HD increased immediately after and the day following skilled training in the absence of changes with non-skilled training. These results support the view that spinal cord function is able to encode a local motor memory.