Two-dimensional, M-mode and Doppler-derived echocardiographic parameters in sedated healthy growing female sheep

Despite the fact that sheep are a widely used animal model in cardiovascular research, reference values for transthoracic echocardiography in normal growing animals are not available. Eight healthy female lambs underwent two-dimensional, M-mode and pulsed wave Doppler echocardiographic examination at 100 days of age and every three months thereafter over a 12-month period. The study was conducted under sedation with midazolam, butorphanol and constant rate infusion of intravenous propofol. Their growth phase was completed at about one year of age. All the echocardiographic parameters considered were significantly correlated with body weight and age class except for the left ventricular systolic and diastolic diameters. Functional indices were not correlated to body weight or age except for the E-point to septal separation distance (EPSS). Doppler-derived parameters were not influenced by independent variables. Transthoracic echocardiography can be considered an applicable method for cardiovascular research using a growing lamb animal model after appropriate adjustments for age and body size.

The effects of different environmental conditions on thermoregulation and clinical and hematological variables in long-distance road-transported calves

The aim of this study was to investigate the effects of long-distance road transport (19 h, from Poland to Italy) during 2 seasons (summer vs. winter) on clinical and hematological variables in calves. The environmental temperature range that could compromise the thermoregulation system (thermal stress) of the calves was tested. For the 7 Holstein calves in each transport, the BW and rectal temperature (RT) were measured, and blood samples were collected at the farm of origin, before loading at the transit center (T2), after unloading at the farm of destination (T3), and 1, 2, 3, and 4 d after arrival. The body temperature (BT) and heart rate (HR) were continuously monitored from T2 to T3. The data were statistically analyzed according to a mixed model that considered the fixed effects of transport (repeated measurements), season of journey, and their interaction. Within the observed temperature-humidity index (THI) range (30 to 80), effective thermoregulation allowed the calves to maintain their BT with small physiologic changes to prevent thermal stress, particularly in the summer. With no seasonal differences, the HR was greater at loading than unloading (120 vs. 115 beats per min; P = 0.012). As for the transport effect, the BW was less (P < 0.001) after unloading, and the RT was greater (P = 0.004). This effect was more marked in summer. The hematological variables indicated a moderate effect of transport on the hydration condition, reactive and muscular systems, and metabolism, although hematocrit (P = 0.004), erythrocytes, cortisol, NEFA, β-hydroxybutyrate, lactate, creatine kinase, lactate dehydrogenase, and aspartate aminotransferase activity (P < 0.001), and total protein (P = 0.007) were greater after unloading. This was confirmed by a moderate decrease in total leukocytes (P = 0.031) and glucose concentration (P = 0.002). The changes in the clinical variables were similar for both seasons even though in the summer, hematocrit (P < 0.001), urea (P = 0.008), and total protein (P = 0.010) increased and glucose concentration (P = 0.038) decreased. In conclusion, the data did not show a pronounced effect attributable to the season of the journey. Long-distance road transport leads to notable changes in clinical and hematological variables at the end of the journey. However, these variables remained within their physiological ranges and returned to basal values within a few days after the journey.

Defective targeting of hemojuvelin to plasma membrane is a common pathogenetic mechanism in juvenile hemochromatosis

Hemojuvelin (HJV) positively modulates the iron regulator hepcidin, and its mutations are the major cause of juvenile hemochromatosis (JH), a recessive disease leading to iron overload. Defective HJV reduces hepcidin up-regulation both in humans and in Hjv-deficient mice. To investigate the JH pathogenesis and the functional properties of human HJV we studied the biosynthesis and maturation of 6 HJV pathogenic mutants in HeLa and HepG2 cells. We show that proteolytic processing is defective in mutants F170S, W191C, and G320V, but not in G99V and C119F. Moreover, we show that mutants G99V and C119F are targeted to the cell surface, while F170S, W191C, G320V, and R326X (lacking the glycosilphosphatidylinositol [GPI] anchor) are mainly retained in the endoplasmic reticulum, although all mutants are released as soluble forms (s-HJV) in a proportion that is modulated by iron supplementation. Membrane HJV (m-HJV) is mainly composed of the cleaved protein, and its level is increased by iron in wild-type (WT) mice but not in the mutants. Altogether, the data demonstrate that the loss of HJV membrane export is central to the pathogenesis of JH, and that HJV cleavage is essential for the export. The results support a dual function for s- and m-HJV in iron deficiency and overload, respectively.

Mutations of Ferritin H Chain C-Terminus Produced by Nucleotide Insertions Have Altered Stability and Functional Properties

Ferritin is an iron storage protein made of 24 subunits. Previous mutational analyses showed that ferritin C-terminal region has a major role in protein stability and assembly but is only marginally involved in the mechanism of iron incorporation. However, it has recently been shown that patients who carry alterations of ferritin C-terminal sequence caused by nucleotide insertions show neurological disorders possibly related to altered protein functionality and cellular iron deregulation. To re-evaluate the role of this region, five mutants of mouse H-ferritin were produced by 2-nucleotide insertions that modified the last 6-29 residues and extended the sequence of 14 amino acids. The mutants were expressed in Escherichia coli and analysed for solubility, stability and capacity to incorporate iron. The alteration of the last 6-residue non-helical extension had no evident effect on the properties of ferritin, while solubility and capacity to assemble in ferritin shells decreased progressively with the extension of the modified region. The results also showed that the modification of even a part of the terminal E-helix abolished the capacity of ferritin to incorporate iron during expression in the cells, probably caused by conformational modification of the hydrophobic channels. The data support the hypothesis that the pathogenic mutations alter cellular iron homeostasis.

Recombinant human hepcidin expressed in Escherichia coli isolates as an iron containing protein

Hepcidin is a small peptide that acts as a regulator of systemic iron homeostasis. To study some of its functional properties, a synthetic cDNA for the minimal, 20-amino-acid, form of human hepcidin was cloned into different constructs for expression in Escherichia coli. The fusion ferritin-hepcidin produced molecules retaining most of ferritin structural and functional properties, including ferroxidase and iron incorporation activities. However, it showed spectroscopic properties compatible with the presence of iron-sulfur complexes on the hepcidin moiety, which was buried into protein cavity. Similar complexes were reconstituted by in vitro incubation of the iron-free protein with iron and sulfide salts. Two other unrelated fusion products were constructed, which, when expressed in E. coli, formed insoluble aggregates retaining a large proportion of total bacterial iron. Analysis of the solubilized preparations showed them to contain iron-sulfur complexes. We concluded that the cysteine-rich hepcidin acts as an iron-sequestering molecule during expression in E. coli. This may have implications for the biological functions of this key protein of iron metabolism.

Identification of New Mutations of the HFE, Hepcidin, and Transferrin Receptor 2 Genes by Denaturing HPLC Analysis of Individuals with Biochemical Indications of Iron Overload

Background: Hereditary hemochromatosis is a recessive disorder characterized by iron accumulation in parenchymal cells, followed by organ damage and failure. The disorder is mainly attributable to the C282Y and H63D mutations in the HFE gene, but additional mutations in the HFE, transferrin receptor 2 (TfR2), and hepcidin genes have been reported. The copresence of mutations in different genes may explain the phenotypic heterogeneity of the disorder and its variable penetrance.

Methods: We used denaturing HPLC (DHPLC) for rapid DNA scanning of the HFE (exons 2, 3, and 4), hepcidin, and TfR2 (exons 2, 4 and 6) genes in a cohort of 657 individuals with altered indicators of iron status.

Results: DHPLC identification of C282Y and H63D HFE alleles was in perfect agreement with the restriction endonuclease assay. Fourteen DNA samples were heterozygous for the HFE S65C mutation. In addition, we found novel mutations: two in HFE (R66C in exon 2 and R224G in exon 4), one in the hepcidin gene (G71D), and one in TfR2 (V22I), plus several intronic or silent substitutions. Six of the seven individuals with hepcidin or TfR2 coding mutations carried also HFE C282Y or S65C mutations.

Conclusion: DHPLC is an efficient method for mutational screening for the genes involved in hereditary hemochromatosis and for the study of their copresence.

Role of iron and ferritin in TNFalpha-induced apoptosis in HeLa cells

We found that tumor necrosis factor alpha (TNFalpha)-induced apoptosis in HeLa cells was accompanied by a approximately 2-fold increase in H- and L-ferritin and a decrease in transferrin receptor, two indices of increased iron availability. Iron supplementation and overexpression of H-ferritin or its mutant with an inactivated ferroxidase center reduced by about approximately 50% the number of apoptotic cells after TNFalpha-treatment, while overexpression of L-ferritin was ineffective. The data indicate that H-ferritin has an anti-apoptotic activity unrelated to its ferroxidase activity and to its capacity to modify cellular iron metabolism.

Effects of a vitamin E-bonded membrane and of glutathione on anemia and erythropoietin requirements in hemodialysis patients

BACKGROUND

The oxidative damage of RBC membranes in hemodialysis (HD) patients increases red blood cell (RBC) susceptibility to hemolysis and impairs cell survival. Reduction of the oxidative stress might lead to better control of anemia and reduction of the erythropoietin (rhEPO) dose.

METHODS

We studied 38 stable HD patients, given a mean dose of rhEPO of 104+/-65 U/kg BW/week, at baseline and during antioxidant treatment with either a full or a 50% dose of EPO. Antioxidant treatment involved the combined use of glutathione, GSH (1200 mg i.v. at the end of each dialysis session) and a vitamin E-bonded HD membrane, CL-E. RBC and reticulocyte counts were done monthly. RBC survival (51Cr T/2) was assayed in 18 patients before and after the end of the study. Oxidative status was determined in 10 patients by measuring plasma concentrations of malondyhaldeide-4-hydroxynonenal (MDA-4HNE), reactive oxygen molecular species (ROMs), and oxydized-LDL (oxLDL) as indices of oxidative stress, alpha-tocopherol and total thiols as single antioxidants, and TAS as a marker of total antioxidant plasma activity.

RESULTS

Antioxidant treatment significantly reduced the high basal plasma concentrations of MDA4HNE and oxLDL, and significantly increased those of alpha-tocopherol, whereas TAS and thiols were unmodified. These changes lasted after the reduction of EPO. Anemia significantly improved with treatment, due to a significant increase in RBC survival. A close direct linear relationship was detected between plasma levels of vitamin E and hemoglobin.

CONCLUSIONS

Adequate control of oxidative stress achieves better control of anemia in HD patients. Since several antioxidant systems are impaired in uremia, the combined use of the CL-E membrane and GSH seems to be the best antioxidant therapy so far, with significant saving of the rhEPO dose.

[Pressure and metabolic effects of terazosin in essential hypertension]

To assess the efficacy and safety of different doses of the alpha-1 blocker terazosin on long-term therapy, 12 essential hypertensives (7 males, 5 females, aged 27-61) were investigated. The study was conducted according to the Latin square design and each patient underwent 4 periods of treatment with 2, 5, 10 mg/day terazosin and placebo, in a double-blind, randomized order. Each treatment lasted 4 weeks. In comparison to placebo, a fall in diastolic pressure was observed already with the 2 mg/daily dose, with a decrease > 10 mmHg in 7 patients (responders). Body weight increased in a dose dependent manner, while atrial natriuretic peptide, serum glucose and insulin during oral glucose tolerance test, total cholesterol, HDL and LDL cholesterol, triglycerides were unaffected. It is concluded that terazosin is effective and safe in essential hypertensives already at 2 mg daily dose. Further reduction in blood pressure at higher doses is likely to be counteracted by salt and water retention.

[The clinical usefulness of tumor markers in thyroid neoplastic pathology. Our experience]

The authors report on the last 100 cases of intervention in which thyroid pathology has been used and also prove how, in their experience, thyroglobulin is an MO, highly specific for CDT. In some cases its dosage changes even in the course of benign thyroid pathology but the value has never exceeded, in these cases, twice the norm. This also confirms, therefore the importance of this MO for the follow up of patients operated on using CDT.

Spirometric lung function. Distribution and determinants of test failure in a young adult population

Spirometric test failure has been defined as failure by a subject to meet the acceptability and/or reproducibility criteria laid down by the American Thoracic Society for measurements derived from forced expiratory maneuvers. The prevalence and determinants of spirometric test failure were examined in 416 men and women aged 20 to 45 yr working in an office environment. In this study population, 11.5% (28 men and 20 women) exhibited test failure for forced expiratory volume in one second (FEV1). The main determinant of test failure in men was bronchial hyperresponsiveness to methacholine challenge (odds ratio 6.7; confidence interval 1.7, 27.1) and in women being a current smoker (odds ratio 4.02; confidence interval 1.13, 14.33). There was also a relationship to eczema in both men and women, but not at a statistically significant level. When FEV1 variability was defined as the difference (in milliliters) between the two best FEV1 values and the results of men and women combined for analysis, significant predictors were a history of eczema, recurrent chest illness in the past 3 yr, and level of bronchial responsiveness to inhaled methacholine. These findings contribute to the gathering evidence that test failure may be of itself an indicator of impaired respiratory health, and its association with bronchial hyperresponsiveness to methacholine in men suggests that in them test failure is related to airway lability, but in women the relationship to smoking suggests an irritative mechanism.

[Primary mucinous carcinoid of the ovary]

A case of primary mucinous carcinoid of the ovary observed in a 52-year-old woman is reported after some remarks on the various histogenetic theories. The observation of this extremely rare cancer was fortuitous during surgery carried out for benign pathology in the contralateral organ. Careful postoperative controls absolutely excluded the possibility of a metastatic tumour. The patient was treated by combining surgery with chemotherapy and eight months after operation is apparently free of cancer.

Visual evoked potentials altered by serum IgG of patients with multiple sclerosis

Immunoglobulin G, isolated from serum of patients with multiple sclerosis was repeatedly injected into guinea pigs and serial visual evoked potentials were recorded. Latency changes indicated a reversible delay in conduction velocity in the central visual pathways. This finding suggests that some component of immunoglobulin plays a role in the pathogenesis of multiple sclerosis.

Urban hospital reaches out to its area's aged

In the medically underserved Bronx, NY, a hospital's gerontology center provides screening, health education, and outpatient services to elderly residents in the community.