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M Alegre

Publications and source records attributed to M Alegre.

At least 37 records · Page 2Linked to original sources
PubMed2001

Unilateral periodic limb movements during sleep in corticobasal degeneration.

Periodic limb movements in sleep (PLM) have been associated with several degenerative disorders and other focal or diffuse diseases. We present a patient with clinical diagnosis of corticobasal degeneration and sleep complaints, in whom video recording and polygraphic study confirmed the presence of right PLM. The unilaterality of the movements and the positron emission tomography findings (hypometabolism in the left frontoparietal, basal ganglia, and thalamic areas) suggest that the loss of inhibitory descending central pathways, with origin in the cortex or basal ganglia, may be involved in the pathogenesis of PLM.

Aged↗
PubMed2001

Brainstem auditory evoked potentials (BAEPs) in the cynomolgus macaque monkey. Equivalence with human BAEPs and proposal of a new nomenclature.

Several groups have studied brainstem auditory evoked potentials (BAEPs) in non-human primates. However, the nomenclature of the waves elicited and their correspondence with human waves I-V differ among authors. BAEPs were recorded from six anaesthetised young cynomolgus macaques (Macaca fascicularis), using different sound stimuli parameters. A constant pattern of four main waveforms was present in all the animals with stimulus intensities over 60 dB SPL, although up to four smaller waveforms were observed in some of the individuals. Latency values increased with decreasing stimulus intensities and with increasing repetition rates. These results were similar to the BAEPs observed in other species of macaques. Although an approximate equivalence between human and monkey BAEPs is possible, some discrepancies suggest that there may be generators which contribute to different waves in both species. This is the reason for our proposal of a new nomenclature for BAEP waveforms in monkeys, following a descriptive order with Arabic numerals preceded by the letter M.

Acoustic Stimulation↗
PubMed2001

Gamma band activity in an auditory oddball paradigm studied with the wavelet transform.

OBJECTIVES: To examine the characteristics of evoked and induced gamma band oscillatory responses occurring during P300 development in an auditory oddball paradigm. METHODS: A time-frequency analysis method was applied to an auditory oddball paradigm in 7 healthy subjects. This method combines a multiresolution wavelet algorithm for signal extraction and the Gabor transform to represent the temporal evolution of the selected frequency components. Phase-locked or evoked activity and also non-phase-locked activity were computed for both standard and target stimuli. RESULTS: The gamma band frequency components differed between target and non-target stimuli processing. The study showed an early and mainly phase-locked oscillatory response appearing around 26--28 ms after both standard and target stimuli onset. This response showed a spectral peak around 44 Hz for both stimuli. A late oscillatory activity peaking at 37 Hz with a latency around 360 ms was observed appearing only for target stimuli. The latency of this late oscillatory activity had a high correlation (P=0.002) to the latency of the P300 wave. CONCLUSIONS: EEG signal analysis with wavelet transform allows the identification of an early oscillatory cortical response in the gamma frequency range, as well as a late P300-related response.

Acoustic Stimulation↗
PubMed2001

Development of a multiplex polymerase chain reaction for the differentiation of bovine herpesvirus-1 and -5.

Bovine herpesvirus-1 (BHV-1) and bovine herpesvirus-5 (BHV-5) are closely related viruses which exhibit some important differences at the genetic and immunogenic levels which may explain the differences in their pathogenicity and epidemiological characteristics. A multiplex polymerase chain reaction (M-PCR) was developed to detect and differentiate between BHV-1 and BHV-5. In this M-PCR two pairs of primers (TK1, TK2 and GD1, GD2) were used in the same reaction mix to amplify a thymidine kinase genomic region (183 bp) of BHV-1 and one genomic region of the gLycoprotein D (564 bp) of BHV-5. The specificity of the M-PCR was demonstrated when using both primers pairs simultaneously with BHV-1 and BHV-5 templates. The two expected bands were amplified without the apparition of non-specific products. However, when other herpesvirus strains were used, there was no amplification. To evaluate the sensitivity of the assay, dilutions of purified viral DNA were made for M-PCR amplification. The detection limit was 7 pg for BHV-1 and 22 pg for BHV-5. It was also determined by comparing the M-PCR with viral isolation. M-PCR was able to detect one log10 more than viral isolation for BHV-1 and for BHV-5 was two logarithms lower. The applicability of M-PCR was demonstrated on different specimens. Twenty isolates from field samples (11 BHV-1 and nine BHV-5) were positive by M-PCR, and the results were completely coincident with previous characterization using the immunoperoxidase assay. M-PCR could detect viral DNA in organ samples from natural infections, such as semen and brain. In addition, M-PCR detected more positive samples than observation of the citophatic effect in cell culture of nasal swabs from experimentally infected animals in two different assays. Owing to the difference in size of the M-PCR products which allows easy identification in an electrophoretic run, it is not necessary to use extra blotting and hybridization steps or a second round of amplification to differentiate clearly between BHV-1 and BHV-5.

Animals↗
PubMed2000

[Supranuclear gaze palsy following extracorporeal surgery with induced hypothermia. Report of two cases].

Although up to 5-20% of the patients who underwent surgery with hypothermia and cardiac arrest may present neurological complications, just a few cases of ocularmotor disorders have been described. Acquired supranuclear ocular motor paresis (ASOMP) is a rare disorder characterized by impairment in volitional and reflex saccades and smooth pursuit in one or more directions of gaze with intact extraocular movements in response to vestibular estimulation. We present two cases of acquired supranuclear ocular motor paresis associated with a peculiar gait disorder. Although a partial improvement was observed, both patients continue with ocular motor paresis in vertical direction after one year of evolution. A selective vulnerability of certain brainstem neuronal groups would explain the pathophysiology of these symptoms.

Adult↗
PubMed1998

Brooke-Spiegler syndrome variant: segregation of tumor types with mixed differentiation in two generations.

Brooke-Spiegler syndrome (BSS) is an autosomal dominantly inherited disease characterized by the development of multiple trichoepitheliomas and cylindromas. Other lesions have been reported to occur in patients with BSS, including parotid basal cell adenomas, milia, organoid nevi, basal cell carcinomas, and spiradenomas. Spiradenomas and cylindromas have so many features in common that they have been regarded as polar extremes belonging to a spectrum of cutaneous adnexal neoplasms. We report on a 61-year-old woman with multiple spiradenomas on the scalp and periauricular areas and her 28-year-old daughter, with multiple facial trichoepitheliomas. Occasional features of pilar and ductal differentiation were found in tissue specimens of tumors from the mother and daughter, respectively. Co-existence of multiple spiradenomas and trichoepitheliomas and segregation of the predominant type of tumor in different members of a family with BSS have been reported occasionally, but never, to our knowledge, in combination. The presence of mixed differentiation in tumor specimens from both patients provides additional evidence in support of the folliculosebaceous apocrine unit (FSAU) hypothesis. Mutations in genes regulating proliferation and differentiation of putative stem cells of the FSAU would give rise to different combinations of adnexal skin tumors as well as to other neoplasms.

Adult↗
PubMed1998

[Mucocutaneous manifestations in acute HIV infection. 3 case reports].

We report three patients who developed a generalized rash with oral, genital or perianal ulcerations as a result of acute infection due to HIV. The primary infection was diagnosed by seroconversion (by means of EIA and Western blot techniques). Definitive diagnosis was established on days 52, 85 and 97 after the appearance of the rash. The p24 protein of the HIV was only detected in the early phase of the disorder in the two cases in which this study was carried out.

Acute Disease↗
PubMed1997

Histopathological changes of primary HIV infection. Description of three cases and review of the literature.

The histopathological changes observed in the cutaneous rash of three patients who suffered the acute phase of HIV infection are described. In all three patients a perivascular and interstitial inflammatory infiltrate was present in the upper and mid-reticular dermis. In one biopsy isolated areas of epidermal necrosis were observed and in the two other biopsies a perifollicular inflammatory infiltrate was detected with perforation in one case. Furthermore, a periductal infiltrate was observed in one of these biopsies.

Adult↗
PubMed1997

Primary neuroendocrine carcinoma of the skin expresses tyrosinase mRNA: detection by a specific nested PCR technique.

BACKGROUND: Tyrosinase transcripts have been identified in a wide range of normal organs and neoplasms such as cutaneous nevi, breast carcinomas, liposarcomas and schwannomas. The cells responsible for these positive results have not been accurately identified yet, but they might correspond to either fully differentiated melanocytes, melanocytic precursors or cells bearing potential for melanocytic differentiation. OBJECTIVE: To assess the expression of tyrosinase mRNA in surgical resection specimens and peripheral blood samples from 2 patients with primary neuroendocrine carcinomas of the skin (PNCS). METHODS: The expression of tyrosinase mRNA transcripts was tested by means of a reverse-transcriptase and nested PCR technique, using specific primers, in tissue samples from surgical specimens and heparinized blood samples from 2 patients with PNCS. RESULTS: The results of the test were positive in the 2 specimens of PCNS but negative in blood samples. CONCLUSION: Our findings provide further support for the hypothesis that PNCS originates from a pluripotent stem cell capable of neuroendocrine cell differentiation, keratin production, and, as reported herein, tyrosinase mRNA expression. It remains to be seen whether this technique can also be applied to patients with PNCS, as an adjunct to staging and treatment planning.

Aged↗
PubMed1995

[The Gorlin syndrome. A review of 11 cases].

Gorlin syndrome is an autosomal dominant disorder with variable penetrance and expressivity. It is characterized by early onset of multiple basal cell carcinomas, mandibular keratocytes, pits of the palms and soles, cerebral ectopic calcification and several skeletal anomalies. We report a series of eleven patients (eight females and three males) with Gorlin syndrome, belonging to nine different families, which have been diagnosed in our Dermatology department during the last ten years. The ages at the moment of diagnosis ranged from 8 to 73 years. Ovarian fibromas were demonstrated in five cases and a frontal parasagittal meningioma in one case. Gorlin syndrome has been recently linked to a putative tumor suppressor gene which has been mapped to 9(q22.3-q31). Further research on the function of the protein encoded by this gene may provide additional insight on the mechanisms leading to oncogenesis in sporadic and hereditary basal cell carcinomas and other tumors.

Adolescent↗
PubMed1993

Serum cytokine levels in human septic shock. Relation to multiple-system organ failure and mortality.

PURPOSE: Cytokines have been associated with the development of sepsis and diffuse tissue injury following septic or endotoxic challenges in humans. Furthermore, relative organ-system dysfunction, not specific organ dysfunction, appears to predict outcome from critical illness. We hypothesized that persistence of inflammatory cytokines within the circulation, reflecting a generalized systemic inflammatory response, is associated with multiple-system organ failure (MSOF) and death from critical illness. In addition, since hepatic function is central to host-defense homeostasis, we further reasoned that critically ill patients with hepatic cirrhosis would have an increased incidence of MSOF and death following sepsis associated with a persistence of cytokines in the blood. PATIENTS AND METHODS: We measured serum levels of tumor necrosis factor (TNF), interleukin (IL) 1, IL-2, IL-6, and interferon gamma (IFG) serially for the first 48 h following the onset of hypotension (systolic blood pressure < 90 mm Hg) thought likely to be due to sepsis in all patients presenting to one ICU. These data were correlated with initial severity of shock and retrospective determination of septic or nonseptic origin, preexistent hepatic cirrhosis, subsequent development of MSOF, and outcome. RESULTS: Fifty-three specific episodes of shock in 52 patients were recorded (35 septic and 18 nonseptic episodes). Mortality was higher in septic patients (41 vs 17 percent, p < 0.01), as was the development of MSOF (29 vs 6 percent, p < 0.001), incidence of cirrhosis (21 vs 0 percent, p < 0.01), and TNF levels over the study interval (p < 0.01). Nonseptic patients also had an initial elevation in TNF over 48-h levels (p < 0.05) that were higher than serum levels reported for normal subjects (chi 2, p < 0.05). There was no relation between peak TNF level and outcome. Sixty-seven percent of the cirrhotic patients had development of MSOF and died, while only 30 percent of the noncirrhotic patients had development of MSOF or died (p < 0.05). The TNF and IL-6 levels in patients who had MSOF or who died were both elevated and did not decrease over time independent of presence or absence of sepsis (p < 0.01). Similarly, IL-6 levels after 12 h were higher in cirrhotic patients than in noncirrhotic septic patients (p < 0.05). No elevation in IL-1, IL-2, or IFG was seen in any patient subpopulation. CONCLUSIONS: TNF and IL-6 serum levels are higher in septic than in nonseptic shock, but the persistence of TNF and IL-6 in the serum rather than peak levels of cytokines predicts a poor outcome in patients with shock.

Cytokines↗