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C Barba

Publications and source records attributed to C Barba.

At least 37 records · Page 2Linked to original sources
PubMed1999

[Changes in prostatic histological composition in subjects with prostatitis].

OBJECTIVES: To explore the links between the histological composition of the prostate and the symptoms related to the clinical BPH. MATERIAL & METHODS: The prostates of 34 patients with symptoms of BPH and 17 asymptomatic patients were biopsied. Using light microscopy, the ratio of stromal to glandular surfaces was calculated. The main dimensions of 5 epithelial cells randomly selected, were examined under electron microscopy in each case. The number and length of microvilli, and the number of secretory granules were determined. The results of symptomatic and asymptomatic subjects were compared by means of Student's t and Mann-Whitney's U tests. RESULTS: The mean ratio of stromal and glandular surfaces came to 4:1 and 6.5:1 in the symptomatic and asymptomatic patients, respectively. The difference was not statistically significant (p = 0.18). Although the average cellular surface of the symptomatic patients was inferior to that of the asymptomatic subjects (74 and 88 mu2. respectively), the differences did not reach statistical significance (p = 0.14). Similarly, the mean nuclear surface of the symptomatic and asymptomatic patients (19.5 and 20.8 mu2, respectively) did not differ (p = 0.48). No differences were detected in the number of secretory granules and microvilli, nor in the length of the microvilli. CONCLUSIONS: The occurrence of symptoms related to the clinical BPH is not due to differences in the composition of the prostate. No clear links seem to exist between the structural changes in the epithelial cells and the development of symptoms. Considering the proportions of epithelium and stroma, therapy focused in the prostatic stroma should yield the best results.

Aged↗
PubMed1998

Dipolar sources of the early scalp somatosensory evoked potentials to upper limb stimulation. Effect of increasing stimulus rates.

Brain electrical source analysis (BESA) of the scalp electroencephalographic activity is well adapted to distinguish neighbouring cerebral generators precisely. Therefore, we performed dipolar source modelling in scalp medium nerve somatosensory evoked potentials (SEPs) recorded at 1.5-Hz stimulation rate, where all the early components should be identifiable. We built a four-dipole model, which was issued from the grand average, and applied it also to recordings from single individuals. Our model included a dipole at the base of the skull and three other perirolandic dipoles. The first of the latter dipoles was tangentially oriented and was active at the same latencies as the N20/P20 potential and, with opposite polarity, the P24/N24 response. The second perirolandic dipole showed an initial peak of activity slightly earlier than that of the N20/P20 dipolar source and, later, it was active at the same latency as the central P22 potential. Lastly, the third perirolandic dipole explaining the fronto-central N30 potential scalp distribution was constantly more posterior than the first one. In order to evaluate the effect of an increasing repetition frequency on the activity of SEP dipolar sources, we applied the model built from 1.5-Hz SEPs to traces recorded at 3-Hz and 10-Hz repetition rates. We found that the 10-Hz stimulus frequency reduced selectively the later of the two activity phases of the first perirolandic dipole. The decrement in strength of this dipolar source can be explained if we assume that: (a) the later activity of the first perirolandic dipole can represent the inhibitory phase of a "primary response"; (b) two different clusters of cells generate the opposite activities of the tangential perirolandic dipole. An additional finding in our model was that two different perirolandic dipoles contribute to the centro-parietal N20 potential generation.

Adult↗
PubMed1998

Dissociation induced by voluntary movement between two different components of the centro-parietal P40 SEP to tibial nerve stimulation.

Whether the two earliest cortical somatosensory evoked potentials (SEPs) to tibial nerve stimulation (N37 and P40) are generated by the same dipolar source or, instead, originate from different neuronal populations is still a debated problem. We recorded the early scalp SEPs to tibial nerve stimulation in 10 healthy subjects at rest and during voluntary movement of the stimulated foot. We found that the P40, which reached its highest amplitude on the vertex at rest, changed its topography during movement, since its amplitude was reduced much more in the central than in the parietal traces. These findings suggest that two different components contribute to the centro-parietal positivity at rest: (1) the P37 response, which is parietally distributed and is not modified by movement, and (2) the 'real' P40 SEP, which is focused on the vertex and is reduced in amplitude during voluntary movement. Since, also, the N37 response did not vary its amplitude under interference condition, it is possible that the N37 and P37 potentials are generated by the same dipolar source. Other later components, namely P50 and N50 were significantly reduced in amplitude during foot movement. Lastly, the subcortical P30 far-field remained unchanged and this suggests that the phenomenon of amplitude reduction during movement (i.e. gating) occurs above the cervico-medullary junction.

Adult↗
PubMed1998

The scalp to earlobe montage as standard in routine SEP recording. Comparison with the non-cephalic reference in patients with lesions of the upper cervical cord.

We compared scalp somatosensory evoked potential (SEP) recordings by non-cephalic and earlobe reference in 14 healthy subjects and in 5 patients with lesions of the upper cervical cord. In healthy subjects, the scalp to earlobe montage tended to cancel all far-field potentials preceding the scalp P14. On the contrary, the P14 far-field was more difficult to identify in scalp to non-cephalic recordings, because in 12/14 cases it followed another far-field (P13), which was very close in latency to the P14. In 4 patients, the scalp to non-cephalic traces showed a single positive wave (P13/P14 complex) in the P14 latency range. If this complex had been labelled as P14, the somatosensory dysfunction would have been localised above the foramen magnum. On the other hand, the scalp to earlobe recording allowed correct localisation of the lesion since it showed the 'real' and delayed P14 in two patients and no far-field response in the remaining two. Therefore, we propose the use of the scalp to earlobe montage as standard in routine examinations.

Aged↗
PubMed1997

Dipolar generators of the early scalp somatosensory evoked potentials to tibial nerve stimulation in human subjects.

We performed the brain electrical source analysis (BESA) of the early scalp somatosensory evoked potentials (SEPs) to tibial nerve stimulation. A four-dipole model could well explain the scalp SEP distribution. One dipole showing a subcortical location was activated at the latency of the lemniscal P30. The three remaining dipoles were located near the sagittal fissure in the hemisphere contralateral to the stimulation. Two of these dipoles showed a biphasic activity and contributed to the signal evoked in the N37-P40 latency range. Also in the N50-P50 latency range two different source activities were involved in SEP building. This finding suggests that one of two possible N50 subcomponents represents the negative counterpart of the N50/P50 dipolar field and the other is originated by a radial source.

Adult↗
PubMed1997

Abnormalities of somatosensory and motor evoked potentials in adrenomyeloneuropathy: comparison with magnetic resonance imaging and clinical findings.

We studied 6 patients with adrenomyeloneuropathy (AMN) showing mild signs of central nervous system involvement. All patients underwent brain and spinal magnetic resonance imaging (MRI) and somatosensory (SEP) and motor (MEP) evoked potential study. Whereas SEPs and MEPs were abnormal in all patients, only 1 patient showed brain MRI abnormalities; spinal MRI showed hypotrophy without focal abnormalities in 4 of 6 patients. Median nerve SEPs, which were recorded with noncephalic reference montage, revealed delayed or absent scalp P14 far-field potential in all patients and abnormal spinal N13 in 2. Moreover, tibial nerve SEPs revealed abnormalities of the subcortical P30 response in all 4 patients in whom scalp-to-ear recording was employed. These findings strongly suggest that in the early stages of disease neurological dysfunction is localized in the spinal cord, where it is difficult to assess using MRI. However, SEPs and MEPs, which show a typical pattern of abnormality in these patients, could be useful in disclosing signs of long tract involvement and in monitoring treatment.

Adrenoleukodystrophy↗
PubMed1996

Influence of the presence of trace amounts of metals on the polymorphism of tolbutamide.

The polymorphism phenomenon causes an important problem in the preparation of many pharmaceutical dosage forms, including oral suspensions, tablets, creams and suppositories. In this work the influence of the presence of certain metallic elements (Ca(II), Fe(III), Mn(II), Zn(II), Cd(II), Ni(II) and Co(II)) in trace amounts on the polymorphism of tolbutamide is described. For these studies, known amounts (5-500 ppm) of different cations were added to ethanol-water solutions of the pharmacologically active polymorph A of tolbutamide prior to its crystallization. These cations were chosen as being among those that commonly appear in drug solutions as a consequence of elution from glass containers. IR studies show that the presence of cations prevents the appearance of the polymorph B of the tolbutamide. Thus, the peaks at 2980, 2940, 2890, 905, 851, 816 and 727 cm-1 (polymorph A) appeared but not the ones at 1045 and 847 cm-1 corresponding to polymorph B. Scanning electron microscopy studies reveal that, in the presence of Ca2+, a third kind of crystal different from polymorphs A and B appears. This form of olbutamide cannot be identified with "polymorph III" of Al-Saieq and Rileys [S.S. Al-Saieq and G.S. Riley, Pharm. Acta. Helv., 56 (1981) 125-129] due to their different IR data. Dissolution rate tests and X-ray diffractometry were also employed in this study. All these results showed that divalent cations partially avoid the transformation of polymorph A into polymorph B.

Cadmium↗
PubMed1995

Factors associated with early onset pneumonia in the severely brain-injured patient.

An analysis of 125 patients with closed head injury was completed in order to identify the risk factors involved in the development of early pneumonia. Pneumonia was diagnosed in 60% of the patients. Early pneumonia developed in 47.8% of the patients. Brain-injured patients who developed early pneumonia were found to have a lower Glasgow Coma Scale (GCS) score. Early pneumonia was found more often in patients with swallowing disorders and evidence of aspiration. Patients who had been intubated in the field were found to be at greater risk for the development of early pneumonia than those intubated in the hospital. Patients with early pneumonia had prolonged intubation times, intensive care unit stays, and hospital stays. This study suggests that a GCS score less than 5, evidence for swallowing disorders and aspiration, and field intubation are risk factors for early pneumonia in the brain-injured patient.

Adolescent↗
PubMed1993

Brain glutathione reductase induction increases early survival and decreases lipofuscin accumulation in aging frogs.

Brain catalase was continuously depleted throughout the life span starting with a large population of initially young and old frogs. Free radical-related parameters were measured in the brain tissue once per year after 2.5, 14.5, and 26.5 months of experimentation. Brain lipofuscin accumulation was observed after 14.5 and 26.5 months, and survival was continuously followed during 33 months. The age of the animal did not decrease endogenous antioxidants nor increase tissue peroxidation either in cross-sectional or longitudinal comparisons. Continuous catalase depletion similarly affected young and old animals, inducing glutathione reductase, tending to decrease oxidized glutathione/reduced glutathione (GSSG/GSH) ratio, decreasing lipofuscin accumulation in the brain, and increasing survival from 46% to 91% after 14.5 months. At 26.5 months of experimentation the loss of the glutathione reductase induction in catalase-depleted animals was accompanied by the presence of higher lipofuscin deposits than in controls and was followed by a great increase in mortality rate. Even though the maximal life span (7 years) was the same in the control and treated animals which were already old (4.2 years) at the beginning of the experiment, the treated animals showed a strong reduction in the rates of early death. It is proposed that the maintenance of a high antioxidant/prooxidant balance in the vertebrate brain greatly increases the probability of the individual to reach the final segments of its species-specific life span.

Aging↗
PubMed1991

Is positive diagnostic peritoneal lavage an absolute indication for laparotomy in all patients with blunt trauma? The Montreal General Hospital experience.

The authors review the use of diagnostic peritoneal lavage (DPL) at The Montreal General Hospital between 1982 and 1987. Fifty-two of 254 patients admitted with a diagnosis of blunt abdominal trauma underwent DPL: results of the procedure were negative in 23 and positive in 29 (grossly positive in 27). Twenty-one of the 23 patients with negative findings were managed nonoperatively; the other 2 underwent laparotomy, which revealed no abnormalities. Nineteen of the 29 patients with positive findings were managed by immediate laparotomy; the other 10 were managed conservatively. The mean (+/- standard deviation) injury severity score (ISS) in the latter group was 13.1 +/- 8.01. The group managed by immediate laparotomy had an ISS of 25.91 +/- 12.81 (p = 0.007). The number of patients suffering from class I or class II shock in the group managed nonoperatively was significantly (p = 0.045) larger than those in the group managed by laparotomy. The authors conclude that a positive result DPL is not a sine qua non for immediate laparotomy in all patients with blunt abdominal trauma. A selective approach can be taken in these patients, considering the severity of the associated injuries and the patient's hemodynamic status. Intensive-care monitoring must be available.

Abdominal Injuries↗
PubMed1984

A placebo-controlled study of the antidepressant activity of moclobemide, a new MAO-A inhibitor.

Preliminary open trials performed by the authors and others with Moclobemide, a new MAO-A inhibitor, indicated that the drug has a satisfactory antidepressant activity. In the present double-blind study Moclobemide has been compared to placebo in a group of 34 unipolar psychotic or neurotic depressed patients. The mean daily dose of Moclobemide was 297 mg and treatment lasted from two to four weeks. Drug effectiveness was measured by improvements in the Hamilton Rating Scale for Depression (HRSD), Clinical Global Impression (CGI) and 100 mm Visual Analogue Scale (VAS). The results have shown that the active drug was markedly superior to placebo. The mean total score of HRSD was reduced from 41.7 to 16.5 in 18 pts. treated with Moclobemide and from 36.3 to 29.1 in 16 pts. who received placebo. Self-assessment with VAS showed a mean reduction from 82.7 mm to 42.2 mm and from 84.3 to 70.6 mm respectively. Moderate to marked improvement was observed by the CGI in 15 cases treated with Moclobemide and mild to moderate in 5 cases who received placebo. The treatment was well tolerated.

Adult↗
PubMed1976

Topical vitamin A acid in the treatment of acne vulgaris (a controlled multicenter trial).

A controlled non-blind multicenter trial was conducted in 211 acne patients to test the activity of topical retinoic acid against sulfur-resorcinol--salicylic acid and placebo. Uniform evaluation criteria were used. After 8 weeks' treatment in comparable groups of patients, retinoic acid proved to be superior to the standard and to the placebo. The difference was statistically significant. Side effects were present in a number of patients treated with the active substances and with the placebo (mainly erythema), but rarely was the treatment discontinued.

Acne Vulgaris↗