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Biomedical subjects

V Martinez

Publications and source records attributed to V Martinez.

At least 19 recordsLinked to original sources
PubMed1992

Immunocytochemical localization of heat-shock protein 60-related protein in beta-cell secretory granules and its altered distribution in non-obese diabetic mice.

Immuno-electron microscopy technique was employed to investigate the cellular distribution of 60 kDa heat-shock protein (HSP60) in pancreatic Beta cells of control and non-obese diabetic mice. In thin sections prepared from control mice, antibody to mammalian HSP60 cross-reacted with protein(s) located to mitochondria and secretory granules. In particular, prominent binding of the antibody was seen to the insulin core of the mature insulin-secreting granules. In comparison, very little immunoreactivity was observed with immature secretory granules or with the Golgi apparatus. No binding to secretory granules or mitochondria was observed with normal mouse serum or with unrelated sera. On Western blots, HSP60 antibody specifically interacted with a single 62 kDa islet cell protein. These results suggest the existence of an HSP60-related protein with a novel location in mature secretory granules of Beta cells. The preferential association of the HSP60-related protein with the insulin core was gradually lost in Beta cells of pre-diabetic non-obese diabetic mice, and correlated with the progression of insulitis. The decrease in the granular binding of the HSP60 antibody was accompanied by an increase in cytoplasm staining, and was concomitant with a significant expansion of the insulin core diameter. The altered distribution of the HSP60-related protein in prediabetic mice, together with our observation that immature secretory granules accumulate in these animals indicate that the presence of HSP60-related protein in secretory granules might be associated with the secretory function of Beta cells.

Aging↗
PubMed1992

Differential effect of calcium and Bay K 8644 on the inhibitory action of estrogens in the rat uterus.

1. The effects of the estrogens estradiol (E2, 10(-7) to 3 x 10(-5) M) and diethylstilbestrol (DES, 10(-7) to 3 x 10(-6) M) on tonic contractions of the rat uterus induced by KCl and CaCl2 have been studied. 2. E2 and DES relaxed, in a dose-dependent way, the tonic contraction induced by KCl (60 mM) (IC50: 5.16 +/- 1.49 x 10(-6) and 4.51 +/- 0.03 x 10(-7) M); the tonic contraction induced by CaCl2 (3 mM) in the rat uterus incubated in depolarizing Krebs (127 mM of K+) have also been relaxed (IC50: 8.6 +/- 0.03 x 10(-7) and 2.56 +/- 0.07 x 10 M) by both drugs. 3. The CaCl2 (0.1 to 10 mM) counteracted the relaxing effect of E2 and DES, respectively, up to 28.13 +/- 10.2% and 34.71 +/- 11.5%, on KCl-induced contractions, and up to 126.36 +/- 19.35% and 95.8 +/- 16.3% on CaCl2-induced contractions. 4. Bay K 8644 (10(-10) to 10(-6) M) reversed the relaxing effect of E2 and DES, respectively, up to 42.49 +/- 2.28% and 43.31 +/- 3.59% on KCl-induced contractions, and up to 21.73 +/- 4.16% and 75.97 +/- 9.63% on CaCl2-induced contractions. 5. Propranolol (10(-6) M) did not modify the relaxing effect of E2 or DES on CaCl2-induced contractions.

3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethy↗
PubMed1992

Secretory granule autoantigen in insulin-dependent diabetes mellitus is related to 62 kDa heat-shock protein (hsp60).

Recent studies in NOD mice suggest that cellular and humoral responses against beta cell protein(s) cross-reactive with mycobacterial heat-shock protein, hsp60, are implicated in the development of autoimmune diabetes. However, this putative, hsp60-related autoantigen has not yet been identified nor have the preceding events triggering the autoimmunity against it. Our recent studies show that antibodies to the mammalian hsp60 bind specifically to the 62 kDa protein located to insulin secretory granules and mitochondria of pancreatic beta cells of healthy mice [1]. In islets of prediabetic NOD mice affected by insulitis, the cellular distribution of this hsp60-related antigen was found to be altered. In the present report, we have examined whether this endogenous hsp60-related protein of secretory granules serves as an autoantigen in type I diabetes. The results of Western blot analysis indicate that diabetic mice sera show reactivity to a 62 kDa islet cell antigen. The NOD mice sera that were positive in detection of the 62 kDa islet cell antigen were also able to recognize the recombinant human hsp60. Immunogold electron microscopy revealed that diabetic NOD mouse sera, cross-reactive to human recombinant hsp60, recognize the antigen located in secretory granules of beta cells. Double-immunogold labelling demonstrated that antigens recognized by both diabetic NOD mice sera and monoclonal hsp60 antibodies co-localized in the same secretory granules of beta cells. Preincubation of islet cell sections with one type of antibody blocks subsequent binding of the other, indicating that epitopes recognized by both antisera on these proteins are shared. Moreover, preadsorption of diabetic sera with the recombinant human hsp60 abolished labelling of secretory granules. These results indicate that the hsp60-related protein of beta cell secretory granules is an autoantigen in type I diabetes in NOD mice.

Animals↗
PubMed1992

A method of analysis of the electrical activity of the proximal gastrointestinal tract of the chicken.

The present paper describes a method of recording and analyzing electromyographical (EMG) signals from the digestive tract of the chicken. The EMG signals from the proventriculus, gizzard, and duodenum were recorded after implantation of Ni and Cr electrodes. The amplified EMG signals were digitized using a sampling frequency of 50 samples per second, and numerical data was stored immediately on the hard disk (1 datum = 1 byte). The software designed allowed: 1) detection of spike-bursts with a high accuracy; 2) analysis of maximum amplitude (with a maximum error of 6.7%), mean amplitude, duration, and frequency of the spike-bursts; the time of interval between spike-bursts, and the percentage of activity; 3) integration of the recorded data with a variable time set; and 4) a wave analysis by means of the Fourier algorithm. These methods, already used in EMG studies in mammals, are assembled and adapted for its application in birds.

Animals↗
PubMed1989

Elevated concentrations of acetone and unidentified compounds in the breath of alcohol abusers.

A highly sensitive gas chromatographic assay was used to measure volatile organic compounds in the breath. Samples of breath from three groups of subjects were studied: normal volunteers (n = 15), acutely intoxicated alcohol abusers (n = 11), and abstinent alcohol abusers (n = 13). Acetone levels were significantly higher in the acutely intoxicated subjects than in the normals (p less than 0.05) or the abstinent alcohol abusers (p less than 0.05). Chromatographic peaks arising from 13 unidentified compounds in the breath were observed; two of these unidentified compounds were observed only in the intoxicated and abstinent alcohol abusers. Statistically significance was achieved in only one unidentified peak; elevated levels of this compound were seen in both acutely intoxicated alcohol abusers (p less than 0.01) and in the abstinent alcohol abusers (p less than 0.01) when they were compared to normal subjects.

Acetone↗
PubMed1988

Aneurysmal bone cyst. A review of 123 cases including primary lesions and those secondary to other bone pathology.

A group of 639 bone lesions was reviewed in order to study the features of the aneurysmal bone cyst and its association with other conditions. A diagnosis of primary aneurysmal bone cyst not associated with any other bone lesion was made in 87 patients. In 36 additional patients the gross and microscopic changes of aneurysmal bone cyst were identified as part of some other solid bone lesion. Fourteen of these additional cases were associated with giant cell tumor (96 cases studied), six with chondroblastoma (41 cases studied), three with chondromyxoid fibroma (45 cases studied), two with nonossifying fibroma (68 cases studied), four with osteoblastoma (61 cases studied), one with fibrosarcoma (50 cases studied), three with fibrous histiocytoma (45 cases studied), two with osteosarcoma (100 cases studied), and one with fibrous dysplasia (42 cases studied). The age, site, and sex distribution of the cases associated with another lesion compares closely with that of the solid lesion concerned, supporting the concept that the aneurysmal bone cyst component is secondary.

Age Factors↗
PubMed1988

Total creatine kinase (CK) and CK-B activity in maternal blood and cord-blood samples after vaginal and cesarean births.

We studied variations in the activity of total creatine kinase (CK; EC 2.7.3.2) and of CK-B in maternal and cord-blood samples, comparing data obtained for vaginal and cesarean births. CK-B activity was determined with an immunoinhibition assay. In all cases, there was a significant postpartum increase in total CK and in CK-B activity in maternal sera, whereas cord-blood samples showed no significant differences between activities in arterial and venous blood for either vaginal or cesarean births. Statistically significant differences were found in CK-B activity, but not in total CK, between cord-blood samples from vaginal births and those from cesareans.

Cesarean Section↗
PubMed1979

Invasive lobular carcinoma of the breast: incidence and variants.

The criteria for the separation of invasive lobular and ductal carcinomas are analysed. Lobular tumours account for 14% of invasive cancers in our material. The widely differing figures given in the literature are mainly attributable to intrinsic difficulties of classification. In addition to the classical dissociated-cell patterns with single filing, a tragetoid appearance and related features, variants with trabecular, loose alveolar and tubular features are recognized; a 'solid' variant requires further investigation. The variants either represent better differentiated forms, or in some cases, an 'earlier' phase in the production of the more traditional Indian file formations and dartboard patterns. Focal signet-ring cell differentiation is another newly-recognized feature. The theoretical and practical implications of these variants are considered. The division into invasive lobular and ductal carcinomas is not as easy as most of the literature implies. Five per cent of cases could not be so classified and, in some of these unclassified cases, both ductal and lobular differentiation may be present. In the diagnosis of problem cases, no single parameter proved reliable but a combination of several parameters enables one to make an objective diagnosis in about 95% of cases.

Breast Neoplasms↗
PubMed1975

Familial chondrocalcinosis in the Chiloe Islands, Chile.

Studies about chondrocalcinosis in the Chiloe Islands (Chile) showed the high frequency of the disease there and how most of it is aggregated in a few highly involved families. Pedigrees and the high degree of consanguinity among parents of index cases pointed to a recessive inheritance. The presence of common Caucasian anthropological features of genetic value in the patients and the lack of Indian mixture in three of the involved families, documented back to 1600, suggest a Caucasian origin of the mutation. Biochemical studies of the patients' synovial fluid showed a significant rise in pyrophosphate concentration. Calcium, phosphorus, and alkaline phosphatase concentrations were not different from a control group.

Adult↗