Continuous monitoring of extracellular lactate concentration by microdialysis lactography for the study of rat muscle metabolism in vivo

A method is described for the measurement and on-line monitoring of muscular extracellular lactate concentration in both anaesthetized and freely moving rats. This method is based on microdialysis sampling and lactic dehydrogenase-catalysed nicotinamide adenine dinucleotide, reduced (NADH)-fluorescence detection techniques. In vivo calibration revealed a resting extracellular lactate concentration of 1.92±0.13 mmol/l (± SEM) in the gastrocnemius muscle of adult male Wistar rats (n=6), while the average whole-blood lactate level was 0.76±0.12 mmol/l (± SEM). This measured extracellular lactate concentration was 1.73-times higher than that deduced from the arterial lactate concentration. Blocking glycolysis with iodoacetate reduced the extracellular lactate concentration to 52±6% (± SEM, n= 4) of the resting level. The extracellular lactate concentration in rat gastrocnemius muscle had increased to significantly (P0.05) different levels, 2.4±0.03 (± SEM) or 4.0±0.55 (± SEM) times the control value, 1 h after aortic clamping (n=3) or cardiac arrest (n=3), respectively. Stimulation of the sciatic nerve induced elevations of the extracellular lactate concentration in the tibialis anterior muscle which were linearly related to the recorded isometric force-time integral. We also monitored on-line the changes in extracellular lactate concentration in the tibialis anterior muscle of a swimming rat. Our results indicate that microdialysis lactate reflects also intracellular metabolism. Lactography may be a useful alternative to biopsies and nuclear magnetic resonance spectroscopy in clinical medicine and physiology for the monitoring of metabolism in vivo.     

Very large peroxisomes in distinct peroxisomal disorders (rhizomelic chondrodysplasia punctata and acyl-CoA oxidase deficiency): novel data

Summary We report very large hepatic peroxisomes (d-circle >1 m) in a patient with rhizomelic chondrodysplasia punctata and a patient with acyl-CoA oxidase deficiency. The effects of peroxisomal enlargement on the enzymatic activity are discussed. As increase in peroxisomal size is also reported in at least 12 other patients with peroxisomal disorders, we propose, a relationship between the enlargement of the organelles and their functional deficiency.     

The evaluation of the performance of a new-concept screen-film system]

Aim of this work is to show the results of the evaluation of the sensitometric properties of a new Du Pont anti cross-over radiographic film system called Ultra Vision, based on a new film and different YTaO4 undoped screens whose emission is centered at about 335 nm. Fog, contrast, latitude, sensitivity, noise and resolution were tested: the MTFs were obtained by exposing a standard resolution pattern and using the "zero"-frequency step as a knife edge. The image of this knife edge was scanned with a microdensitometer with a 20 microns slit. The results (at 70 kVp with 2.5 mm Al and 2.5 mm Cu total filtration), compared with those of Du Pont conventional radiographic screen-film systems Cronex 10 S/Quanta, show that the new system significantly increases contrast, sensitivity and resolution and will consequently improve, in the clinical use, radiographic image quality.     

Grafted fetal suprachiasmatic nucleus cells survive much better in tissue pieces than in suspension

A comparison was made between the survival of fetal suprachiasmatic nucleus (SCN) grafted either in tissue pieces or as tissue suspension. Donor tissue was obtained from day 15, 16 or 17 Wistar fetuses, and stereotaxically placed in the dorsal thalamus of the brain of vasopressin(VP)-deficient Brattleboro adult rats. One month post-grafting, the suspension grafts largely failed to show the immunocytochemical presence of VP- and vasoactive intestinal polypeptide(VIP)-producing SCN cells, but solid piece grafts did. In the suspension grafts only a few tiny clusters of surviving VP SCN neurons were seen and hardly any VIP cells. This suggests that intrinsic contacts are necessary for SCN cells to survive and/or to express their genotype. Efferent VP fiber growth was observed to run from the tissue piece derived SCN grafts towards the periventricular area of the thalamus, a nearby SCN projection area. However, the number of VP efferents was very limited and not consistently present. Surprisingly, magnocellular VP neurons, also present in the fetal SCN grafts, showed an opposite survival pattern. Several of such cells were seen in day 15 suspension grafts, whereas hardly any were found in day 15 tissue piece grafts. These results indicate that the type of graft preparation might be important when survival of particular cells is desired.     

Calbindin-D28K (CaBP28k)-like Immunoreactivity in Ascending Projections

This study concerns the involvement of calbindin-D28K (CaBP28k)-containing neurons in ascending spinal projections to the brainstem (nucleus of the solitary tract, lateral reticular nucleus area), pontine (parabrachial area) and mesencephalic (periaqueductal grey) structures. All these central structures are important in the processing of visceroception and visceronociception and all are targets for spinal efferents from similar areas. CaBP28k controls the excitability of cells by acting on intrinsic calcium metabolism. Results refer to the caudal spinal areas where the visceroceptive regions are concentrated. Experiments were performed through a double labelling approach that combined the retrograde transport of a protein - gold complex to identify the projection cells and immunohistochemistry to identify the CaBP28k-positive cells. The caudal spinal cord is rich in both CaBP28k-containing and projection cells. Cells colocalizing the protein and the retrograde tracer were quite numerous, with a particularly high concentration in the superficial layers of the dorsal horn (laminae I and outer II) and the lateral spinal nucleus. The other spinal areas containing immunoreactive projection cells were the reticular part of the neck of the dorsal horn, the medial laminae VII and VIII, lamina X and the sacral parasympathetic nucleus. The superficial layers and the neck of the dorsal horn are targets for nociceptive, visceroceptive and thermal inputs; the sacral parasympathetic column and lamina X are involved in visceroceptive integration. A functional role for the lateral spinal nucleus has not yet been established. Quite similar results were obtained for each of the ascending pathways under study. The high incidence of CaBP28k in spinal pathways suggests that calbindin has a major role in controlling the excitability of spinal cells subserving the processing of visceroception and/or visceronociception information to supraspinal levels. The participation of CaBP28k-immunoreactive cells in spinal ascending tract cells largely outnumbers those previously reported for various neuropeptides (Leah et al., Neuroscience, 24, 195 - 207, 1988)     

Congenital generalized lipodystrophy associated with multiple sclerosis

We report the case of a 22 year old woman with congenital generalized lipodystrophy who presented a left brachiocrural pyramidal hemisyndrome, bilateral cerebellar signs and a left cranial nerve VI deficit. The clinical pattern had a tendency to regress. MRI brainscan, CSF examination and clinical features led to the diagnosis of probable demyelinating syndrome. Published data on CNS involvement in patients with congenital generalized lipodystrophy are few and we have found no cases in which a demyelinating syndrome is associated. In the case we report it is tempting to see the disorder of the lipid metabolism underlying the congenital generalized lipodystrophy as underlying the myelin disorder as well.

---

Sommario Descriviamo il caso di una paziente di 22 anni, affetta da Lipodistrofia Congenita Generalizzata, che ha presentato una sintomatologia caratterizzata da emisindrome piramidale brachiocrurale sinistra, segni cerebellari bilaterali e deficit del VI nervo cranico di sinistra. Il quadro clinico ha avuto una tendenza alla regressione. La RMN encefalo, l'esame del liquor e la clinica hanno fatto porre diagnosi di probabile sindrome demielinizzante. I dati della letteratura relativi al coinvolgimento del SNC in pazienti con Lipodistrofia Congenita Generalizzata sono scarsi ed in particolare non abbiamo rilevato casi di associazione con sindrome demielinizzante. Nel caso descritto è suggestivo che la turba del metabolismo lipidico alla base della Lipodistrofia Congenita Generalizzata possa essere in rapporto all'interessamento della mielina.

     

DSM-III mental disorders in general medical sector: a follow-up and incidence study over a two-year period

Summary In three general medical settings (general practice, hospital medical wards and emergency rooms) about 20% of the adult attenders had a DSM-III mental disorder, mainly in the area of affective and anxious disorders. Some of these disorders were quite severe. Of those cases reassessed 1 year and 2 years after the first interview, less than a quarter reached a no-diagnosis status. The chronicity of most cases dependent on the interplay not only of either relapse or duration of the main disorder but also of comorbidity and incidence of new disorders. A high incidence of more transient disorders in subjects who were well at first assessment was also found.     

Selective arterial embolization in the treatment of aneurysmal bone cyst and angioma of bone

Nineteen aneurysmal bone cysts and five angiomas of bone were treated by selective arterial embolization. The median follow-up was 22 months. In 17 patients healing occurred with complete relief of symptoms; in 11 of these almost complete ossification of the lesion resulted. In the remaining cases, little or no ossification was apparent but ossification may take 1 year or more to occur. No recurrence was observed in any of these cases. Recurrence occurred only in two cases. In one, growth of the recurrence stopped after a second embolization, and the X-rays showed no change. Selective arterial embolization represents a treatment of choice in aneurysmal bone cyst and angioma of bone especially of the spine, sacrum, or pelvis. In these sites embolization replaces surgery which might be hazardous due to intraoperative bleeding.Supported in part with Rizzoli Research Funds     

The role of spontaneous portosystemic shunts in the course of orthotopic liver transplantation

Spontaneous portosystemic shunts are commonly found in cirrhotic patients. Not yet established is their role after orthotopic liver transplantation (OLTx), especially when an increase in portal pressure develops, as during early acute rejection. In this study, 34 cirrhotic patients in a series of 70 OLTx are considered. Each patient had preoperative angiographic assessment, and, in 21 (62%), large spontaneous portosystemic shunts were evident. In 12 cases the shunts were not affected by the surgical procedure and were present during the postoperative period; in 9 the hepatectomy itself involved interruption of the shunts. The patient population was divided into two groups: patients with postoperative shunts (n=12) and those without (n=22). The two groups were similar in age, sex, Child's stage, transplantation variables, and number and grade of rejection episodes. However, mean transaminases (AST) values in the first 2 weeks were significantly higher levels in shunt versus nonshunt patients (421±335 vs 183±126; P<0.025), and this was even more evident when rejection occurred (626±375 vs 195±129; P<0.001). Furthermore, during an acute rejection reaction, three cases showed a true steal phenomenon through the large reopened shunts with ischemic damage to the grafts. The data indicate a possible detrimental effect of the spontaneous shunts on graft perfusion and suggest the prophylactic surgical interruption of the residual shunts during the transplantation.     

Intrafamilial phenotype variation in Friedreich's disease: possible exceptions to diagnostic criteria

Summary Three families are described which include members with typical Friedreich's disease (FD) and others who are ataxic but do not satisfy all the diagnostic criteria for that disease. In family A two patients have an early-onset, rapidly progressive FD, while two others have a late-onset, more benign form. In families B and C one member has typical FD, and another has a similar ataxic syndrome, except for preservation of knee jerks. Laboratory evaluation is consistent with the diagnosis of FD in all cases. FD diagnosis appears justified in secondary cases with late onset or preserved tendon reflexes, provided that the index case fulfils all diagnostic criteria. Whether the diagnosis of FD is tenable in sporadic atypical cases remains to be seen. Echocardiographic and neurophysiological examination may be valuable in classifying such cases.