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Biomedical subjects

L Martín

Publications and source records attributed to L Martín.

At least 19 recordsLinked to original sources
PubMed2000

Tubulin folding cofactor D is a microtubule destabilizing protein.

A rapid switch between growth and shrinkage at microtubule ends is fundamental for many cellular processes. The main structural components of microtubules, the alphabeta-tubulin heterodimers, are generated through a complex folding process where GTP hydrolysis [Fontalba et al. (1993) J. Cell Sci. 106, 627-632] and a series of molecular chaperones are required [Sternlicht et al. (1993) Proc. Natl. Acad. Sci. USA 90, 9422-9426; Campo et al. (1994) FEBS Lett. 353, 162-166; Lewis et al. (1996) J. Cell Biol. 132, 1-4; Lewis et al. (1997) Trends Cell Biol. 7, 479-484; Tian et al. (1997) J. Cell Biol. 138, 821-823]. Although the participation of the cofactor proteins along the tubulin folding route has been well established in vitro, there is also evidence that these protein cofactors might contribute to diverse microtubule processes in vivo [Schwahn et al. (1998) Nature Genet. 19, 327-332; Hirata et al. (1998) EMBO J. 17, 658-666; Fanarraga et al. (1999) Cell Motil. Cytoskel. 43, 243-254]. Microtubule dynamics, crucial during mitosis, cellular motility and intracellular transport processes, are known to be regulated by at least four known microtubule-destabilizing proteins. OP18/Stathmin and XKCM1 are microtubule catastrophe-inducing factors operating through different mechanisms [Waters and Salmon (1996) Curr. Biol. 6, 361-363; McNally (1999) Curr. Biol. 9, R274-R276]. Here we show that the tubulin folding cofactor D, although it does not co-polymerize with microtubules either in vivo or in vitro, modulates microtubule dynamics by sequestering beta-tubulin from GTP-bound alphabeta-heterodimers.

3T3 Cells↗
PubMed2000

Transgrediens et progrediens palmoplantar keratoderma (Greither's disease) with particular histopathologic findings.

We describe a patient with transgrediens et progrediens palmoplantar keratoderma (Greither's disease). Ten of the 25 members of this patient's family in six consecutive generations were affected by the disorder. The pedigree was consistent with an autosomal dominant inheritance pattern, with variable penetrance. The proband's physical examination showed typical signs of Greither's disease. The most striking findings were seen in histopathologic study and consisted of round, focal areas of orthohyperkeratosis located on delled areas of the epidermis. These histopathologic features were present in both the lesions of the palms and dorsum of the hands. We review the clinical manifestations and histopathologic findings of this particular variant of palmoplantar keratoderma and the differential diagnosis.

Biopsy, Needle↗
PubMed1999

Pyodermatitis-pyostomatitis vegetans: report of a case and review of the literature.

Pyodermatitis-pyostomatitis vegetans is a benign, rare disorder characterized by a pustular eruption in the oral mucosa and vegetating plaques involving the groin and axillary folds. Its association with inflammatory bowel disease is well established. We report the case of a 49-year-old-white man with ulcerative colitis who manifested a vegetating, annular plaque in the left inguinal region of 2 months' duration. Oral examination disclosed an erythematous mucosa with multiple painful pustules involving the labial and gingival mucosa. Histopathologic study demonstrated epidermal hyperplasia and an inflammatory infiltrate composed mostly of neutrophils and eosinophils, grouped into microabscesses within the epidermis and with a bandlike configuration in the upper dermis. Results of direct and indirect immunofluorescence studies were negative. We discuss the differential diagnosis between pyodermatitis-pyostomatitis vegetans and pemphigus vegetans.

Anti-Inflammatory Agents↗
PubMed1999

The O blood group protects against venous thromboembolism in individuals with the factor V Leiden but not the prothrombin (factor II G20210A) mutation.

We investigated the influence of the ABO blood group in the observed prevalences of the recently described factor V R506Q and factor II G20210A mutations in a thrombotic population. We determined the ABO blood group in a sample of 178 unselected patients (aged 17-83 years), diagnosed at our center with deep vein thrombosis or pulmonary embolism. The results of this study show a high prevalence of thrombosis in the non-O blood group. In the general population, the prevalence as a fraction of the O blood group was 2.69 (confidence interval 1.90-3.82). Of the factor V R506Q carriers (n = 28), only one had O group blood and 27 of 28 were non-O (24 A, one B and two AB). However, within the group of factor II G20210A carriers (n = 17), seven had O, nine A and one B type blood. The prevalence of the factor V R506Q mutation within the O blood group was 2.4% (one of 42), significantly lower than in the A group (23.3%, 24 of 103; P = 0.002), or in the overall non-O group (19.9%, 27 of 136; P = 0.006). This prevalence was similar to that observed previously in the non-thrombotic population in our area (3.5%; P = 0.9). We analyzed the clotting activity of factor VIII and we found higher levels in the non-O group (1.78+/-0.61 U/ml) than in the O blood group (1.30+/-0.51 U/ ml; P < 0.0001). We speculate that factor Va in individuals with the factor V Leiden mutation could interact with the high levels of factor VIII clotting activity as a necessary cofactor.

ABO Blood-Group System↗
PubMed1998

Acquired hypertrichosis lanuginosa: case report and review of the literature.

Acquired hypertrichosis lanuginosa is a rare cutaneous disorder usually associated with internal malignancy that consists of the development of abnormal hair growth of the lanugo type, often confined to the skin of the face and neck, although other areas also may be involved. We report on a 66-year-old woman with a metastatic ductal infiltrating carcinoma of the breast who developed growth of fine lanugo type hair on her face and progressive growth of the hair of eyebrows and eyelashes. We review the literature on this uncommon paraneoplastic cutaneous disorder emphasizing the pathogenic mechanisms that have been proposed to explain the striking overgrowth of lanugo type hair.

Aged↗
PubMed1998

Predictive factors of oxygen desaturation during upper gastrointestinal endoscopy in nonsedated patients.

BACKGROUND: Hypoxemia can occur during upper gastrointestinal endoscopy with or without pharmacologic sedation. We investigated possible predictive factors of severe oxygen desaturation (SaO2 < 90%) in nonsedated patients undergoing endoscopy. METHODS: A total of 481 patients who underwent upper gastrointestinal endoscopy without sedation were monitored with continuous pulse oximetry. Multivariate logistic regression analysis was used to identify factors related to the patient, the examination, and the monitoring data that would predict severe desaturation. RESULTS: Mild desaturation (SaO2 between 90% and 94%) was found in 23.7% of the patients, and severe desaturation (SaO2 < 90%) was found in 6.4%. The variables found to predict severe desaturation were basal SaO2 < 95% (odds ratio 67.7), respiratory disease (odds ratio 30.5), more than one attempt needed for intubation (odds ratio 39.4), emergency procedure (odds ratio 14.9), and American Society of Anesthesiologists score of III or IV (odds ratio 3.9). CONCLUSIONS: The predictive variables analyzed in this study can be used to identify patients who are at increased risk for desaturation. Such patients require very close monitoring (pulse oximetry at a minimum). Endoscopists and assistants should be especially alert to the possibility of respiratory depression in these patients.

Adult↗
PubMed1998

Spinulosis of the face as a manifestation of demodicidosis.

We describe a 78-year-old woman with polycythaemia rubra vera who had multiple tiny follicular hyperkeratotic spicules on the cheeks. She was receiving treatment with oral hydroxyurea, but no topical agents had been applied to her face. Histopathological study demonstrated numerous Demodex folliculorum mites within dilated follicular infundibula, and we consider that the mites were playing a part in the aetiology of the skin lesions.

Aged↗
PubMed1998

Cutaneous manifestations of infection by nontuberculous mycobacteria.

Cutaneous infections by nontuberculous mycobacteria (NTM) are not usual but their relative importance has changed during the last few years and still further changes are expected. This study comprised 13 patients from whom NTM were recovered from skin biopsy specimens, sinus exudates or cutaneous abscesses. All samples were processed according to standard methods, and the isolates were identified by biochemical testing. Skin biopsy specimens, when available, were processed for histopathological study. The clinical records of the patients were reviewed, and the relevant clinical, microbiological and epidemiological data collected. The clinical manifestations were noted to be relatively nonspecific and consisted of draining sinuses, abscesses, ulcers and nodules with multicentric or sporotrichoid patterns. Tissue culture isolated Mycobacterium fortuitum complex in nine patients, M. avium in three, and M. marinum in one. In the nine patients studied by histopathology, various patterns were observed. These included dermo-hypodermal abscesses, suppurative granulomas, tuberculoid granulomas and granulomas with a perifollicular distribution. Cutaneous lesions can thus be the first and the only sign of NTM disease, and culture still remains the definitive diagnostic procedure.

Adult↗
PubMed1997

Influence of malnutrition on the prevalence of bacterial translocation and spontaneous bacterial peritonitis in experimental cirrhosis in rats.

Bacterial translocation (BT) has been involved in the pathogenesis of spontaneous bacterial peritonitis (SBP) in experimental cirrhosis. Because malnutrition is a common feature in cirrhosis, the aim of this study was to evaluate the effect of nutrition on BT and SBP. We induced cirrhosis in 44 Sprague-Dawley rats by administration of oral CCl4, and, afterward, 26 animals were maintained with dietary restriction. Cultures of mesenteric lymph nodes (MLN), peripheral and portal blood, liver, and spleen were performed. SBP occurred in 48% of the rats with ascites, this being more frequent in the malnourished animals (80%) than in control rats (29%). BT appeared in all the rats with SBP (100%) but only in 57% without it. In the malnourished animals, the BT rate was 95%, while it was 30% in the control group. These results suggest that malnutrition increases the BT rate and the risk of developing SBP in experimental cirrhosis, and that BT is frequent in cirrhosis and may play a role in the development of SBP.

Animals↗
PubMed1997

Clear-cell porocarcinoma: another cutaneous marker of diabetes mellitus.

The relationship between clear-cell syringoma and diabetes mellitus is well established. We present a case of clear-cell porocarcinoma in a diabetic patient. The lesion consisted of a 5-cm nodule on the lateral aspect of the left leg. Histopathologically, the neoplasm was composed of irregular aggregations of neoplastic cells with striking clear-cell appearance, showing features of ductal differentiation. The clear-cell appearance of neoplastic cells was due to glycogen accumulation within their cytoplasm. Immunohistochemistry and ultrastructural studies also supported the diagnosis of a neoplasm with sweat ductal differentiation. Enzyme histochemical reactions for phosphorylase immunoreactivity on fresh, unfixed sections of the neoplasm demonstrated that this immunoreactivity was remarkably decreased. Some adnexal neoplasms of the skin mostly composed of clear cells may be cutaneous markers of diabetes mellitus. Phosphorylase activity deficiency in diabetic patients may be responsible for glycogen accumulation in neoplastic cells resulting in clear-cell appearance of these neoplasms.

Acrospiroma↗
PubMed1997

Dermatomyositis with a pityriasis rubra pilaris-like eruption: a little-known distinctive cutaneous manifestation of dermatomyositis.

A pityriasis rubra pilaris-like eruption has been described in patients with dermatomyositis. These patients showed generalized follicular hyperkeratosis and diffuse thickening of the palms and soles. Histopathological findings consisted of keratotic plugging of the follicular infundibulum and features of erector pili myositis. We report on an 18-year-old woman with dermatomyositis. The diagnosis was established by characteristic enzymatic alterations, electromyographic pattern of myositis and the findings in a muscle biopsy, although the patient had no evidence of muscular weakness during a follow-up of 14 years. She developed an erythematosus and squamous eruption associated with diffuse palmoplantar keratoderma. Histopathological features consisted of a papillomatous epidermis with spicules of compact eosinophilic hyperkeratosis over the tips of papillae that were not related to hair follicles. Pityriasis rubra pilaris-like eruption seems to be a characteristic although uncommon cutaneous manifestation in dermatomyositis.

Adolescent↗
PubMed1997

[Small intestine adenocarcinoma with Crohn's disease].

We report a 57-year-old male with a 11-years history of Crohn's disease who developed small bowel adenocarcinoma. The patient was admitted with intestinal partial obstruction and he underwent a laparotomy because an abscess in right lower quadrant was suspected. He was successfully treated with resection and adjuvant chemotherapy, without evidence of recurrence after a 2-year follow-up. A review of the literature reveals that about 100 cases have been reported. We describe the distinguishing features of small bowel adenocarcinoma arising in Crohn's disease and we emphasize the difficulty in making an early diagnosis.

Adenocarcinoma↗
PubMed1997

[Spontaneous bacterial peritonitis from Campylobacter fetus].

A patient with cirrhosis and ascites who developed spontaneous bacterial peritonitis due to Campylobacter fetus is described herein. This organism has been increasingly associated with bacteremia and localized infections in patients with cirrhosis and other immunocompromised states, but spontaneous bacterial peritonitis has been rarely reported. We review Campylobacter fetus infections and their relationship to development of spontaneous bacterial peritonitis, and we emphasize that prolonged antimicrobial therapy is required.

Campylobacter Infections↗
PubMed1996

Cutaneous metastases from prostatic carcinoma.

Cutaneous metastasis from carcinoma of the prostate is a rare phenomenon. When it occurs, metastases usually appear as multiple nodules involving the suprapubic area and the anterior aspect of the thighs. We report on two cases of cutaneous metastases from prostatic carcinoma, one of them presenting the stereotypical clinical and histopathological findings, whereas in the other one cutaneous metastasis consisted of a morphea-like plaque on the chest. Histopathologically, the later case revealed accumulations of neoplastic cells distributed in a folliculotropic pattern. In both examples immunohistochemical study with prostatic specific antigen (PSA) confirmed the prostatic origin of the metastases. We review the literature on this subject.

Aged↗
PubMed1996

Unilateral areolar sebaceous hyperplasia in a male.

We report a case of areolar sebaceous hyperplasia involving the right mammary areola in a 49-year-old male. Areolar sebaceous hyperplasia, an uncommon entity first described by Catalano and Ioannides in 1985, is characterized clinically by yellowish thickening of the areolae and histopathologically by large numbers of mature hyperplastic sebaceous lobules connected to the skin surface through short, hairless infundibular canals. Since its original description, only two additional reports have been published. To our knowledge, our patient is the first reported of areolar sebaceous hyperplasia in a male.

Humans↗
PubMed1996

Keloidal basal cell carcinoma. A new clinicopathological variant of basal cell carcinoma.

Basal cell carcinoma is the commonest malignant neoplasm of the skin. Clinical and histopathological variants are well known. We describe two patients with nodular lesions on the face, clinically suggestive of keloids, but with no previous history of injury at that site. Histopathological study, in both cases, demonstrated characteristic basaloid neoplastic aggregations of basal cell carcinoma, intermingled with thick, sclerotic, keloidal collagen bundles in the stroma. This peculiar stroma is responsible for the clinical and histopathological characteristics. We propose the name of keloidal basal cell carcinoma for this striking and distinctive variant of basal cell carcinoma.

Aged↗