Stimulating amino acids in epilepsy: possibilities of treatment

Stimulating amino acids (glutamine and aspargine) play an essential role in epileptogenesis. Activating receptors NMDA, AMPA, kainate and metabotropic influence a conduction of ion canals and a beginning, duration and extinction of epileptic discharges. Some of the new anti-epileptic drugs introduced in the recent years modify functioning of glutamine receptors subtypes. It is expected that they can also decrease a release of glutamines, amplify a GABA-ergic suppression and block sodium channels. Most information about these drugs in epileptogenesis was received in animal experiment which is an excuse for a lack of certainty in a parallel referring their mechanisms to the central nervous system in a man. Treatment resistant focal or general epilepsies and some epileptic syndromes are the most often appearing indications for using agents producing an effect on activating amino acids system. They are most often used in an added therapy, more rarely in a monotherapy. Some negative comments concern not very clear influence on cognitive functions, however some hope arises due to a potential neuroprotective mechanism being a result of a decreased glutamine release. The drugs blocking a stimulating transmission should be a good supplement for a present possibilities of epileptic treatment.     

Participation of low-threshold calcium spikes in excitatory synaptic transmission in guinea pig medial frontal cortex

We studied the activation of low-threshold calcium spikes (LTS) by excitatory postsynaptic potentials in pyramidal neurons from guinea pig medial frontal cortex with intracellular recording. We used extracellular bicuculline and phaclofen and intracellular QX-314 to block inhibitory synaptic potentials and sodium currents. Postsynaptic potentials were evoked by stimulation of layer I. We found that large (> 10-15 mV) excitatory synaptic potentials evoked from membrane potentials more negative than -75 mV were able to trigger LTS. The activation of LTS resulted in an increase of the rising slope or amplitude of the synaptic potentials depending on the size of the excitatory postsynaptic potential (EPSP). We used 100 microM NiCl2 to confirm the presence of LTS as part of the EPSPs. The N-methyl-D-aspartate (NMDA) and non-NMDA components of the excitatory synaptic potentials were isolated using (+/-)2-amino-5-phosphonovaleric acid (APV; 50 microM) or 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX; 20 microM); both components could, independently, trigger an LTS. With recordings made with K+ acetate-filled electrodes, we show that the activation of LTS was critical to allow excitatory synaptic potentials to reach the threshold of action potential firing; also, this amplification of synaptic responses produced the firing of more than a single action potential by the postsynaptic cell. These results demonstrate that in cortical pyramidal neurons the activation of low-threshold calcium spikes results in the amplification of synaptic responses.     

Serotonergic and noradrenergic function in depression: clinical correlates

The present study was conducted in order to investigate the relationships between central noradrenergic (NA) and serotonergic (5-HT) function and clinical characteristics of a major depressive episode according to the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition. We measured growth hormone response (ΔGH) to clonidine (CLO) (an α2 NA agonist), as an index of central NA function, and prolactin response (APRL) to d-fenfluramine (d-FEN) (a specific 5-HT releaser/uptake inhibitor), as an index of central 5-HT function, in 53 medication-free depressed inpatients. On the basis of their CLO and d-FEN test responses, patients were classified into 4 groups. Group 1 (blunted ΔPRL(d-FEN) alone [11 %]) was characterized by a recent violent suicide attempt, a high degree of medical damage, and mild anxiety. Group 2 (blunted ΔGH(CLO) alone [32%]) was characterized by an absence of a history of suicide attempt and by severe anxiety. Group 3 (combination of blunted ΔGH(CLO) and APRL(d-FEN) [18%]) was characterized by a history of suicide attempts, total duration of the illness of over W years, age over 40 years, and more than 3 previous hospitalizations. Group 4 (no abnormality [39%]) had no specific clinical profile. These results suggest that, in depression, specific psychopathological features may be linked to 5-HT and/or NA dysfunction. However, our results also suggest that NA and/or 5-HT dysfunction are less likely to be the primary cause of mood disorders but are more indicative of failure of compensatory mechanisms involved in affective homeostatic processes.     

Dural enhancement in pituitary macroadenomas

We describe the normal dural enhancement patterns of the sellar region and determine whether the duramater is affected by pituitary macroadenomas. Dural enhancement appeared to be usually abnormal in 20 patients with pituitary macroadenoma compared with 20 control patients, mainly at the planum sphenoidale and carotid sulcus. However dural changes are subtle and their recognition requires knowledge of the normal enhancement patterns. Dural changes, reported in a variety of inflammatory and infectious dural diseases and after surgery, are not specific and may be also seen in pituitary macroadenomas. Received: 12 December 1998 Accepted: 3 November 1999     

Lymphangioma of the spermatic cord

We report a new case of spermatic cord lymphangioma in a infant 2 years old. The initial diagnosis was funicular hydrocele. The treatment was the local excision of tumor and the diagnostic was histological. Postoperative course was excellent. Must be explored the transillumination of the mass which would have led us to think other the diagnosis different from that of the cord hydrocele before the operation since it would have given negative. During the operation, must the assured that the cystic anomaly is limited to spermatic cord, to evite recurrences in the postoperative course.     

Absorptive hypercalciuria type III or caused by renal loss of phosphates

Contribution of a retrospective series of 16 patients with type II absorptive hypercalciuria over a total of 1.041 patients undergoing metabolic study due to relapsing renal lithiasis. Clinical history of lithiasis, biochemistry prior to treatment and instituted therapy were examined in all cases. Stones composition, radiologic appearance of lithiasis and evolution of biochemical parameters after medical treatment with a mixture of phosphates were also studied.     

Retroperitoneal benign schwannoma. Report of a new case

The schwannoma is a tumor resulting from the Schwann cells of neural shwath, being its retroperitoneal localization quite unusual. This tumor is clinically unspecified and in most of the cases it originates symptoms coming from the compression of the close structures when its localization is retroperitoneal. Its diagnosis is quite often fortuitous being confirmed by anatomopathological study afterwards. The treatment is surgical radical exeresis with subsequent followup. We report a new case of this uncommon retroperitoneal pathology in a female patient showing a nonspecific clinic. Two years after the surgery she remains asymptomatic without any radiological evidence of recidive.     

Paratesticular lipoma

Among the neoplasias affecting the scrotum and other elements contained within, testicular tumours are the most common; paratesticular neoplasias account for about 2%. 70% of them are benign tumours, lipoma being one the most frequent types. We contribute a new case of paratesticular lipoma in a 45-year old patient, who presented with scrotal complaints. Physical examination found fibroelastic scrotal tumoration; diagnosis being aided with ultrasound and CAT that showed fat tissue radiographic patterns. Complete removal of tumoration and subsequent pathoanatomical study confirmed the diagnosis of paratesticular lipoma. A literature review on the subject is included with reflections on the clinical, diagnostic and therapeutical aspects.     

Malignant mesothelioma of the tunica vaginalis

Case report of a new case of malignant mesothelioma of the tunica vaginalis testis. A mediterranean male age 62, presented with enlargement and swelling of the scrotum, treated as orchiepydidymitis within the previous 3 months. Physical and ultrasonography examination showed a left scrotal mass with extension to the skin of the scrotum. After surgery (orchiectomy and partial hemiscrotectomy) and histopathology diagnosis of locally advanced malignant mesothelioma, CT showed metastasis in retroperitoneum, Lung and Liver. The patient undergoes chemotherapy and radiotheraphy with a poor prognose. We review the diagnosis, histopathology and therapeutical approach for this uncommon kind of paratesticular tumor (less than 80 cases reported in the last 30 years).