Biomedical subjects
Publications and source records attributed to P Martini.
Tadalafil, a type 5 phosphodiesterase inhibitor, is a new and effective therapy for erectile dysfunction. It has unique pharmacokinetic properties in its drug class, which also includes sildenafil and vardenafil. It is also well tolerated with few side-effects, and can be used in difficult patients such as neuropaths or diabetics.
The role of androgens in human sexuality as regards the mechanism of erection and the pathogenesis of impotence is under debate. In addition, it is difficult to define the psychosocial impact of both hypogonadism and androgen replacement. However, sexual hormones largely influence mood, well-being, and quality of life. For this reason, despite the methodological difficulties of assessment, testosterone replacement has a deep impact on the social, psychological and sexual life of the treated patient. Considering the obvious characteristic of testosterone as an hormone, it appears evident that the endocrinologist is the unique experienced specialist able to diagnose and treat the hypogonadal men, monitoring potential side effects and following the psychosocial issues of androgen therapy.
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It is well known that raising mean luminance speeds-up the visual response to temporal change. At higher mean luminance, the temporal impulse response function (IRF) becomes more transient or biphasic. An analogous effect is observed physiologically when stimulus contrast is increased, at constant mean luminance. As stimulus contrast is raised, the temporal response to flicker advances in phase and becomes more transient (bandpass). The MC (magnocellular) retinal ganglion cells manifest this temporal contrast gain control, but the PC (parvocellular) cells do not. We show psychophysically that the temporal response in humans speeds-up in an analogous manner as stimulus contrast is raised. Low spatial-frequency gratings, of suprathreshold contrast, were presented as pairs of pulses, separated by brief delays. Responses became more transient with increasing contrast in both our motion task (direction discrimination) and in our flicker task ('agitation' discrimination), mimicking the temporal contrast gain control seen in the physiological studies. Results could be modeled with a nonlinearity, in which the IRF shortens with increasing contrast.
Cutaneous vasculitides continue to be difficult to diagnose and treat because of the complexity of these disorders. Current classification schemes are based on clinical findings and histopathologic criteria, so biopsy of an early evolving lesion is the most effective means of establishing the diagnosis. We describe the case of a 74 years old man suffering from livedo reticularis and painful nodular lesions, with ulcers, on the legs. Establishing a precise diagnosis has required biopsy of the lesions which showed histopathologic feature of cutaneous polyarteritis nodosa and the designation of cutaneous vasculitis as "isolated" or "primary" was based on lack of systemic disease documented by clinical findings, laboratory tests and instrumental investigations. Remission occurred after moderate doses of steroid therapy and after a year of management with low dose of steroid therapy the patient experienced significant improvement. Cutaneous polyarteritis nodosa is usually a benign disease, however it may relapse, and a long range follow up of the patient is necessary because of the possibility of systemic involvement.
Neuropsychological evidence suggests that face recognition based on configural (holistic) information can occur in isolation from recognition based on local feature cues. The present study shows that configural processing can be isolated experimentally in normal subjects. A phenomenon is reported that exists only for upright whole faces, namely categorical perception (CP) of face identity in noise. Three discrimination tasks (ABX, better likeness, and similarity ratings) were used to test for perceptual distortion across the category boundary predicted from binary classification of face morphs. Noise was added such that any single local region provided unreliable cues to identity. Under these conditions, CP was found for upright faces but not for inverted faces or single features, even with more than 10,000 trials. The CP-in-noise signature phenomenon was then used to show that configural processing survives image plane rotations of 45 degrees-90 degrees.
The action of nuclear hormone receptors is tripartite, involving the receptor, its ligands, and its coregulator proteins. The estrogen receptor (ER), a member of this superfamily, is a hormone-activated transcription factor that mediates the stimulatory effects of estrogens and the inhibitory effects of antiestrogens such as tamoxifen in breast cancer and other estrogen target cells. To understand how antiestrogens and dominant negative ERs suppress ER activity, we used a dominant negative ER as bait in two-hybrid screening assays from which we isolated a clone from breast cancer cells that potentiates the inhibitory activities of dominant negative ERs and antiestrogen-liganded ER. At higher concentrations, it also represses the transcriptional activity of the estradiol-liganded ER, while having no effect on other nuclear hormone receptors. This clone, denoted REA for "repressor of estrogen receptor activity," encodes a 37-kDa protein that is an ER-selective coregulator. Its competitive reversal of steroid receptor coactivator 1 enhancement of ER activity and its direct interaction with liganded ER suggest that it may play an important role in determining the sensitivity of estrogen target cells, including breast cancer cells, to antiestrogens and estrogens.
OBJECTIVE: To study the prevalence of hepatitis C virus (HCV) infection in 2 groups of patients, one group with psoriasis and the other with psoriatic arthritis (PsA). METHODS: We detected anti-HCV antibodies by ELISA and by a recombinant immunoblot assay (RIBA) in the sera of 50 patients with psoriasis and 50 with PsA. As controls we used a group of 76 patients with rheumatoid arthritis (RA), and referred to data on the prevalence of HCV in the general Italian population. RESULTS: By ELISA, anti-HCV antibodies were detected in 6/50 (12%) patients with PsA, in 5/50 (10%) patients with psoriasis, and in 4/76 (5.2%) patients with RA. All the reactive PsA and RA sera also tested positive on RIBA, while only 3 of the 5 positive results for sera of patients with psoriasis were confirmed by RIBA. The prevalence of HCV infection in patients with psoriasis was not significantly higher than in controls. In contrast, the rate of HCV infection observed in the 50 patients with PsA was higher than that in the other groups, the difference being statistically significant between patients with PsA and the general population. CONCLUSION: Our data do not support the hypothesis that HCV infection may play a role in the pathogenesis of psoriasis. On the other hand they show a statistically significant difference between the prevalence of HCV infection in patients with PsA and the general population.
BACKGROUND: Prostate trophism depends on DHT formed from T by the enzyme 5alpha-R. Two 5alpha-R isoforms with different biochemical characteristics have been cloned. Also estrogens might contribute to the prostate growth; however, their intraglandular formation by the enzyme aromatase is still debated. The aim of the present study was to verify whether (a) only one or both isoforms of the 5alpha-Rs are expressed in the prostate cancer cell line LNCaP and in BPH, or (b) the aromatase is present in these samples. METHODS: The profile of the pH optimum of the 5alpha-Rs was evaluated "in vitro" in LNCaP cells by the production of labeled 5alpha-reduced metabolites either from [14C]-T or [14C]-D4 at pH 3.5-8. The gene expression of the two 5alpha-Rs and of the aromatase in LNCaP cells and in BPH specimens was analyzed by RT-PCR combined to Southern blot analysis, using specific sets of oligonucleotides. The tissue localization of 5alpha-R1 was analyzed by immunohistochemistry using an anti-5alpha-R1 polyclonal antibody. RESULTS: (a) In LNCaP cells, the formation of 5alpha-reduced metabolites from the respective precursors increases progressively as a function of pH, being the highest at neutral pH values; (b) the 5alpha-R1 isoform is expressed in both LNCaP cells and in BPH, while the 5alpha-R2 mRNA is present only in BPH, but not in LNCaP cells; and (c) no aromatase transcripts were observed either in BPH or in LNCaP cells. CONCLUSIONS: A careful examination of the possible differential expression of T-activating enzymes, particularly in prostate cancer, would be of help to choose the appropriate treatment.
A 46 year-old woman presented with a weakness of the left side. MRI of the brain showed a left temporal meningioma, a left temporal lobe herniation and two high-signals in the right cerebral peduncle. The involvement of the pyramidal tract in the foot of the cerebral peduncle, in this case, results from temporal lobe hemiation. These findings are different from the mechanisms reported in other cases of ipsilateral hemiplegia. The ipsilateral hemiplegia syndrome was classically described by Ectors in relation to a meningioma of the foot of the third frontal circonvolution. Pathophysiological theories of ipsilateral hemiplegia are reviewed.
We have measured sensitivity for discriminating the spatial phase of multi-harmonic and two-harmonic patterns modulated either in luminance or in chromaticity (red-green). The multi-harmonic patterns were either highpass squarewaves, lines or ramps. For all patterns, contrast thresholds for discriminating 0 from 180 deg phase were similar to those for discriminating -90 from 90 deg, for luminance or chromatic modulation (or both). For all types of multi-harmonic patterns, the ratio of contrast thresholds for the phase discrimination to that for pattern detection was the same for luminance and chromatic modulation, and for combinations of both. Similarly, phase thresholds, the minimum detectable differences in phase (about a mean 0 deg), were the same for chromatic and luminance patterns, provided that contrast was scaled to equate detection thresholds of the patterns. Similar results were observed for simple three-harmonic patterns (f + 2f + 3f), and for (f + 2f) two-harmonic patterns. Strangely, however, two-harmonic patterns of f + 3f (first two terms of square-wave) of moderate to high spatial frequency did show a two-fold advantage for luminance over colour, as Troscianko and Harris (1988) have previously reported (Vision Research, 28, 1041-1049), possibly because the two harmonics have a greater separation in frequency. However, for most classes of patterns, sensitivity for spatial phase is as good for chromatic as for luminance modulation, suggesting that similar sorts of mechanisms operate under these two conditions.
The authors describe the most important chemical-physical characteristics of the slime of the Terme San Giovanni in Elba Island, both with reference to the inorganic component, and especially to the organic one. The latter principally comes from the presence in the extraction basin of green algae of Caulerpa genus and of two sea plants, Zoostera marina and Posidonia oceanica. The presence of sulphur, in the organic components of slime, and of iron, in the inorganic one, provide the peloid peculiar properties which are very interesting in the treatment of dermatological diseases.
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Computed tomography is the essential examination in patients with severe manifestations of neurological disorders. We discuss emergency situations involving the central nervous system due to vascular and infections lesions. Trauma and acute complications of brain tumours, usually seen within a neurosurgical context, are not discussed here.
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A case of pure motor hemiparesis due to a pontine lacunar infarct is reported. Infarction was related to vertebrobasilar ectasia identified on CT, MRI and MR angiography. MR studies provide accurate information on anatomical location, residual lumen, partial thrombosis, mass effect on brain stem and CSF pathways and vascular complications.
We report two cases of unilateral upper cervical spinal cord infarction in the territory supplied by the anterior spinal artery. Early nonspecific MRI abnormalities consisted of hypointense T1 signal and hyperintense T2 signal. A late MRI study showed partial decrease in lesion size due to perifocal edema resorption with negative Gd-DTPA enhancement. The presumed cause of infarction was occlusion of a sulcocommissural artery or of the ipsilateral nutrient branch of the spinal artery.
Applications of Condress (patented sheets of pure bovine collagen) on open skin surfaces (30 cases of "ulcus cruris", 5 cases of decubitus, and malum perforans; 10 cases of full-thickness burns) were examined in a controlled trial. Quantification of regeneration speed, macrophotographic survey of granulation tissue and epithelial border, thermographic and chromometric evaluation of the skin microcirculation, and histological observation of regenerating tissues, were the parameters used. The following results were obtained: marked reduction of healing time, different aspects of the granulation-tissue responses, different times of topical collagenolysis, increased vascular perfusion, histological activation of angiogenesis, fibrogenesis, histiomacrophage function and superficial absorption. The employment of Condress in burn areas seems to be highly promising.