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M T González

Publications and source records attributed to M T González.

At least 19 recordsLinked to original sources
PubMed2006

Similarity and structure of the ectoparasite communities of rockfish species from the southern Chilean coast in a temporal scale.

The understanding of the patterns and processes underlying the structure of parasite communities has progressed significantly in the last years; however, much of the evidence available to date on parasite community comes from unconfirmed studies. In this study the ectoparasite communities of 2 related rockfishes, Sebastes capensis and Helicolenus lengerichi, from the southern Chilean coast (ca. 40 degrees S) were examined to determine whether their specific compositions are similar, structured in non-random ways, and repeatable among years. From 2001 to 2004, 189 specimens of S. capensis and 101 of H. lengerichi were examined, 10 and 9 parasite species were recorded in S. capensis and H. lengerichi, respectively. Component ectoparasite communities of these hosts were taxonomically similar (60%), but the abundances and prevalences of their parasites differed significantly among years and between hosts. The most prevalent species were Lepeophtheirus chilensis, and Microcotyle sp. for S. capensis, and Microcotyle sp., Juanetia continentalis, and Interniloculus chilensis for H. lengerichi. Infracommunities of S. capensis showed higher species richness and parasite numbers than those of H. lengerichi. The similarity among infracommunities (measured as parasite abundance) varied significantly among years both within and between hosts. Despite this, temporal nestedness patterns were observed in infracommunities of these hosts, suggesting that their ectoparasite communities are structured and might be predictable in time, at least in the southern Chilean coast where they share the same habitat.

Animals↗
PubMed2005

Spatial and temporal predictability of the parasite community structure of a benthic marine fish along its distributional range.

The search for consistent patterns of organisation in parasite communities remains a central theme in parasite community ecology. However, to date, much evidence comes from studies without replication in both space and time; when replicate communities are examined, repeatable patterns are rarely observed. Here we determine, using nested subset analyses, whether the infracommunities of ectoparasites and endoparasites of a benthic marine fish (Sebastes capensis) show non-random structure. Then we examine the spatial repeatability of parasite community structure across the host's distribution in the southern Pacific, and the temporal repeatability of ectoparasite community structure from one locality. In total, 537 fish were captured from different latitudes (between 11 degrees S and 52 degrees S) along the Pacific coast of South America; a further 122 specimens were captured in two other years from one of the sampling localities, Valdivia (40 degrees S). In spite of variation in fish sizes among samples, fish size generally did not correlate with either ecto- or endoparasite species richness. The ecto- and endoparasite species richness of the component communities were also not correlated with fish sample size across the nine localities. Significant nested patterns were found in the ectoparasite communities of S. capensis at all eight localities, except at latitude 52 degrees S. Significant nested patterns were also found in the endoparasite infracommunities of S. capensis at seven of the nine localities, the exceptions being those from latitudes 11 degrees S and 20 degrees S. On a temporal scale, significant nestedness was observed in the ectoparasite infracommunities of S. capensis during each of the 3 years of sampling at Valdivia. In general, the same parasite species are responsible for the repeatability of nested patterns, though their importance varies among localities. The spatial and temporal predictability of the parasite community structure in S. capensis may be associated with the fish's benthic habitat and territorial behavior, suggesting that host biology may be a key determinant of the structure of parasite communities.

Animals↗
PubMed2005

Nested patterns in parasite component communities of a marine fish along its latitudinal range on the Pacific coast of South America.

A major goal of community ecology is to identify and explain non-random patterns of species composition. To date, the search for nested patterns in parasite component communities of the same fish host species has not been attempted, despite the fact that this higher hierarchical level is more relevant to nestedness analyses. The aims of this study are first, to determine the structure of component communities--considering ectoparasites and endoparasites separately--of a marine fish (Sebastes capensis) with an extended geographical distribution along the southeastern Pacific and, second, to explain these patterns by taking into account the extrinsic factors associated with the distribution of this host fish. From April to September 2003 and from April to August 2004, 537 fish were captured from different latitudes along the southeastern Pacific. The component communities of both ectoparasites and endoparasites of this fish host showed significant nested subset patterns. However, the type of nestedness pattern differed between ectoparasites and endoparasites. Ectoparasite component communities of S. capensis show higher species richness between latitude 30 degrees S and 40 degrees S, whereas endoparasite component communities show higher species richness between 40 degrees S and 52 degrees S. A nested pattern in ectoparasite component communities of S. capensis result from the gradual loss of some ectoparasites species southward and northward of the central part of their latitudinal distribution, which can be explained by the interaction of S. capensis with other host fish species from the central Chilean coast. Nestedness in endoparasite component communities of S. capensis is produced by the gains and losses of species toward the south of their latitudinal distribution, caused by changes in their prey-items (intermediate hosts) along their latitudinal distributional range.

Animals↗
PubMed2002

Nearly space-filling fractal networks of carbon nanopores.

Small-angle x-ray scattering, nitrogen adsorption, and scanning tunneling microscopy show that a series of activated carbons host an extended fractal network of channels with dimension D(p) = 2.8-3.0 (pore fractal), channel width 15-20 A (lower end of scaling), network diameter 3000-3400 A (upper end of scaling), and porosity of 0.3-0.6. We interpret the network as a stack of quasiplanar invasion percolation clusters, formed by oxidative removal of walls between closed voids of diameter of approximately 10 A and held in registry by fibrils of the biological precursor, and point out unique applications.

Journal Article↗
PubMed2002

[Isotopic renal study in diabetic nephropathy].

UNLABELLED: This study aimed to evaluate the prognostic value of the kidney split function (KSF), the effective renal plasma flow (ERPF) and glomerular filtration rate (GF) in the evolution of diabetic nephropathy. MATERIAL AND METHODS: 125 patients (IDDM:10, NIDDM:115), including 62 men, ages 18-84 years, were studied. In all cases GF (Cr 51 EDTA), ERPF (131I-hippuran), kidney split function (obtained from the 99mTc-MAG3 renogram) and basal serum creatinine (SC) were evaluated at the beginning of the study and patients were clinically followed up for 5 years by SC. Ultrasound and/or intravenous digital angiography were performed in 120 patients. RESULTS: In patients with decreased ERPF (76 patients) the SC increased progresively during the 5 years, in both those with elevated PC (N = 54) as well as in those with normal baseline SC (n = 22). In patients with normal ERPF the SC did not change significantly during the study. An asymethric split function (KSF < 40% in one kidney) was found in the renogram of 42 patients; in 32 of them the ERPF was decreased. Of these, ulttrasonography was normal in 9, and vascular and/or obstructive pathology was demonstrated by ultrasonography or digital angiography in only 6 patients. CONCLUSION: The ERPF becomes altered earlier than serum creatinine in patients with diabetic nephropaty. ERPF and split function calculation, and FG seems to have higher prognostic value than ultrasounds in the management of diabetic nephropathy. Radionuclides seems to be an accurate test than the ultrasonography to detect renal function abnormalities in patients with diabetic and thus can be an examination of choice in these patients.

Adolescent↗
PubMed2002

[Dyslipidemia and cardiovascular risk in type 2 diabetes mellitus patients with associated diabetic nephropathy].

BACKGROUND: Diabetes patients with concomitant diabetic nephropathy are especially destined to cardiovascular complications due to the presence of microalbuminuria or proteinuria, that are potent inductors of dyslipidaemia. METHODS: We have studied 98 type 2 diabetes mellitus patients, 61 male and 37 female, mean age 63 +/- 13 year old, all of them with overt proteinuria (above 500 mg/day), divided into 4 groups: G-I (n = 13): patients with t. cholesterol > 6.25 mmol/l treated with fibric-acid derivatives; G-II (n = 52): hypercholesterolemic patients treated with statins; G-III (n = 20): hypercholesterolemic patients with no lipid-lowering intervention; G-IV (n = 13): normocholesterolemic patients (control group). Lipidic profile, proteinuria and renal function have being compared after 1, 3 and 5 years. RESULTS: Base-line characteristics of the patients were similar when regarding age, onset of diabetes or nephropathy. Only proteinuria was higher in statins-treated group (p < 0.05). Fibric-acid derivatives were more effective on hypertriglyceridaemia while statins were more effective lowering LDL cholesterol. A gemfibrocyl-treated patient presented a rhabdomyolysis episode. Statins were safe and well tolerated. Nine patients (19%) in G-II, 2 patients (10%) in G-III and 1 patient (7%) in G-IV achieved end-stage renal failure. Five-year cardiovascular mortality and all-cause mortality rate were 23%/23% in G-I, 13%/19% in G-II, 20%/25% in G-III and 31%/31% in G-IV. The difference was statistically significant when comparing normocolesterolemic versus statin-treated patients (p < 0.05). CONCLUSION: Lipid-lowering therapy could probably delay but not avoid the progression of diabetic nephropathy. Since dyslipidaemia is closely related to the progression of cardiovascular disease and mortality, an aggressive lipid-lowering therapy is recommended, irrespectively of its potential effect on diabetic nephropathy.

Aged↗
PubMed2001

Efficacy of interferon for chronic hepatitis C virus-related hepatitis in kidney transplant candidates on hemodialysis: results after transplantation.

OBJECTIVES: Interferon-alpha (IFN) may have undesirable effects on a functioning graft. The aim of this study was to evaluate IFN treatment in kidney transplant candidates during the hemodialysis period as well as the results after transplantation. METHODS: A total of 29 noncirrhotic hemodialysis patients with chronic hepatitis C virus (HCV) infection (based on long-term rise in ALT, HCV serology, HCV RNA by polymerase chain reaction methods, and histological evidence) were included. Tolerability to IFN treatment, pre- and posttransplantation therapeutic results, and long-term outcome were recorded. IFN regimen consisted of 3 million units (MU) times per week after hemodialysis sessions for 6 months, followed by 1.5 MU after each hemodialysis session for an additional 6 months. All patients gave informed consent for participation. RESULTS: IFN therapy was fairly well tolerated. Adverse effects due to IFN toxicity, renal disease, or causes related to the immunological properties of IFN were observed in 24% of patients. At the end of treatment, ALT had normalized in 23/28 patients (82.1%), and HCV RNA had cleared in 23/28 patients (82.1%). During follow-up, HCV RNA was persistently negative in 18 patients (64%, including transplant recipients). A total of 14 patients (nine HCV RNA-negative) received a kidney transplant. Mean follow-up after the procedure was 41 +/- 28 months. In all, 12 patients had a functioning graft, one had acute vascular rejection, and one died of carcinoma. All transplanted patients maintained normal ALT levels, and eight remained HCV RNA-negative. CONCLUSIONS: Treatment results in our study population were better than those observed in the general population. The long-term response achieved, which was maintained after transplantation, supports the use of IFN for HCV hepatitis in kidney transplant candidates under hemodialysis.

Adult↗
PubMed2001

Metazoan parasite fauna of the bigeye flounder, Hippoglossina macrops, from Northern Chile. Influence of host age and sex.

The metazoan parasite fauna of Hippoglossina macrops (n = 123) from northern Chile (30 degrees S) is quantitatively described for the first time, and the role of host age and sex was evaluated. Twelve parasite species were recovered, including 5 ectoparasites (2 Monogenea, 2 Copepoda and 1 Piscicolidae) and 7 endoparasites (1 Digenea, 3 Cestoda, 2 Acanthocephala, and 1 Nematoda). The copepod Holobomolochus chilensis, the monogenean Neoheterobothrium sp., the adult acanthocephalan Floridosentis sp. and the hirudinean, Gliptonobdella sp. are new geographical and host records. The most prevalent ectoparasitic species were the monogenean, Neoheterobothrium sp. and the copepod, H. chilensis. Among endoparasites, the acanthocephalans Floridosentis sp. and Corynosoma australe were most prevalent and abundant. Prevalence and mean intensity of infection for most parasitic species were not affected by host sex, however the prevalence of Floridosentis sp. was significantly greater in males. Intensity of infection was positively correlated with host age for Neoheterobothrium sp., and negatively correlated for Floridosentis sp. and H. chilensis. The helminth species richness of the host H. macrops was lower compared to related flatfishes from the Northern Hemisphere. The relationship of the helminth fauna of H. macrops, its feeding habits and ecological habitats are discussed.

Age Factors↗
PubMed1999

[Renal failure secondary to diabetic nephropathy. A review of the characteristics of the diabetic patients who started dialysis in Catalonia in 1994].

The appearance of diabetic nephropathy and its progression towards renal failure can be prevented if an early treatment is instituted. However, diabetes is currently one of the main causes of entry into a dialysis program. Therefore, the diagnostic characteristics of renal disease in 105 patients who started dialysis in Catalonia in 1994 were reviewed; the presence of other changes associated with diabetes were assessed. The results showed that 81.7% of patients had proteinuria higher than 0.5 g/24 h, and 40.5% had plasma creatinine higher than 5 mg/dl at the first nephrological control. As a result, the period between diagnosis of nephropathy and the inclusion in the dialysis program was very short (3.7 years) and considerably shorter than that reflected in literature for other countries, whereas the incidence of other micro and macrovascular complications was similar. Remarkably, a high number of smokers and treatment with oral antidiabetic drugs (33%) at the end stage of renal failure was observed. These results suggest that follow-up of diabetics should be more exhaustive and serial tests be performed to detect nephropathy early. An appropriate control during renal failure stage can also postpone the disease progression and avoid the appearance of complications which at present have a high morbid-mortality and high cost.

Adult↗
PubMed1998

[Prevalence of nephropathy in type I diabetes].

BACKGROUND: Diabetic nephropathy is a serious complication of diabetes, of which there are few epidemiological data in Spain. The aim of this study is to determine diabetic nephropathy prevalence in a group of patients with type I diabetes mellitus, representative of the population of Barcelona, Spain, evaluating several risk factors related with its development. PATIENTS AND METHODS: 639 patients (296 males and 343 women), from 6 hospitals, selected according with the diabetes duration (194 between 5 and 9 years [group I], 227 between 10 and 19 years [group II] and 218 with 20 years or more [group III]) were studied. In all patients urinary albumin excretion and plasma levels of creatinine, HbA1c, cholesterol and triglycerides were determined. The presence of retinopathy, neuropathy, vasculopathy and tobacco consumption were also evaluated. RESULTS: The prevalence of diabetic nephropathy increased with longer diabetes duration (8.1% [CI: 4.3-11.9] in group I, 24.7% [CI: 19.1-30.3] in group II and 44.7% [CI: 38.1-51.3] in group III), as well as that of hypertension, diabetes complications, cholesterol and triglycerides plasma levels. Related to people with normal renal function, after logistic regression, microalbuminuria was associated with hypertension and longer diabetes duration. Clinical nephropathy (macroalbuminuria + renal failure) to hypertension, longer duration, hypertriglyceridemia, male sex and tobacco consumption. CONCLUSIONS: The prevalence of diabetic nephropathy in Barcelona area is high and similar to that observed in other european regions. Its existence is associated with other diabetic complications. In addition to the classic risk factors, tobacco consumption must also be considered as a factor for diabetic nephropathy.

Adult↗
PubMed1998

[Use of 99mTc-tetrofosmin scintigraphy in the diagnosis of patients with hyperparathyroidism].

UNLABELLED: The aim of the work was to study the diagnostic value of 99mTc-tetrofosmin to localize anomalous parathyroid glands in patients with hyperparathyroidism. METHODS: We have studied 33 patients: 12 with primary and 21 with secondary hyperparathyroidism, 9 of them renal graft recipients. Sixteen patients underwent surgery, 12 with primary and 4 with secondary hyperparathyroidism. All patients were injected with 740 MBq of 99mTc-tetrofosmin. Subsequently at 15, 30 and 60 minutes images were acquired for 300 seconds using a pin-hole collimator. A pertechnetate thyroid scintigraphy was obtained in 7 cases (24-48 h later) when the thyroid activity made difficult the identification of parathyroid glands. RESULTS: In the group of patients with primary hyperparathyroidism, all cases showed a focal uptake in lower right localization. In the secondary hyperparathyroidism group, 12 patients showed diffuse tracer uptake in two or more glands and histology confirmed hyperplasia in four of them. Seven cases showed a greater focal uptake in a gland: two of them were renal graft recipients and three were chronic renal failure cases in haemodyalisis, and two were evaluated postsurgery showing uptake in the remnant parathyroid gland. The two remaining patients had a normal scintigraphy and corresponded to two false negative cases. In conclusion, our results suggest that 99Tc-tetrofosmin may be used as a suitable tracer for preoperative detection and screening of anomalous parathyroid glands.

Adenoma↗
PubMed1998

Metazoan parasites of the red rockfish Sebastes capensis off northern Chile.

The parasites of the red rockfish Sebastes capensis off northern Chile are described quantitatively for the first time and compared with those of congeneric species of the Northern Hemisphere as well as of other Chilean marine fishes. Sixteen species were recorded, including 8 ectoparasites (2 copepods, 2 isopods, 1 turbellarian, and 3 monogeneans) and 8 endoparasites (2 acanthocephalans, 3 digeneans, and 3 nematodes). The ectoparasites Lepeophtheirus chilensis and Caligus cheilodactylus, and the endoparasites Pseudopecoelus sp. and Corynosoma sp. were predominant. Eighty percent of the fishes harbored 3-6 parasite species. Four parasite genera new to the genus Sebastes were found in S. capensis, which also shares several parasite genera with its congeneric species from other geographic areas. However, in contrast to its congeners, S. capensis exhibits a lower helminth species richness, although when all the metazoan fauna is considered the species number and diversity are similar. When compared with other demersal fishes of the Chilean coast, S. capensis shows a high number of species and high parasite abundance. Diphtherostomum sp. and Gnathia sp. are new generic records for the parasite fauna of Chilean coast fishes and the finding of Paramicrocotyle sp., Neobenedenia melleni, and Interniloculus chilensis in this study represents a new geographical record for these parasites.

Acanthocephala↗
PubMed1997

[The prediction of the degree of metabolic control by minimal technical norms in a diabetes program].

OBJECTIVE: To assess whether scores on the minimum technical norms (MTN) of the diabetes mellitus programme are of use in determining the level of metabolic control achieved. DESIGN: A retrospective study. SETTING: Two teaching health centres in the city of Santander. PATIENTS AND OTHER PARTICIPANTS: 204 patients, the total chosen by the Santander area management for the 1994 annual evaluation of the Diabetes programme. MEASUREMENTS AND RESULTS: The values reached by the variables of the MTN were measured. For a control criterion we took the value of glycosylated haemoglobin HbA1C or over. 52% of patients fulfilled the criteria of good control, 20% acceptable and 28% bad. CONCLUSIONS: Scoring on the MTN has little value in predicting lower values of HbA1C and is no use in assessing the level of metabolic control achieved by the Diabetes programme. The evaluation of the programme should include results indicators.

Community Health Centers↗