PubMed Health⌕ Search

Biomedical subjects

T Arends

Publications and source records attributed to T Arends.

At least 19 recordsLinked to original sources
PubMed1994

The role of intrarectal ultrasound (IRUS) in staging of rectal cancer and detection of extrarectal pathology.

Intrarectal Ultrasound (IRUS) is rapidly becoming an effective tool in the staging of rectal cancer. Twenty-nine consecutive patients with adenocarcinoma of the rectum underwent both CT scanning and IRUS in the preoperative assessment of rectal cancer in an effort to correlate IRUS staging with surgical pathology, correlate tumor staging comparing IRUS with CT scan, and determine incidence of extrarectal pathology by IRUS. Patients were reviewed as to IRUS stage, results of CT scan, TNM stage of extirpated tumor, incidence of genitourinary pathology, and sonographic result of preoperative radiotherapy (RT). The mean age of all patients was 69 years; there were 25 males and four females. Twenty-four patients underwent proctectomy with either low pelvic anastomosis or end stoma; five underwent local surgical therapy. Thirteen patients received preoperative RT. CT scan correlated poorly with IRUS staging of tumors penetrating the muscularis propria. IRUS overstaged 40 per cent, understaged 5 per cent, and correctly staged 55 per cent of patients when compared with pathological specimens. Eleven of the 25 males (44 per cent) had abnormal prostates by IRUS. Five (20%) had further urologic intervention, resulting in two prostatic cancers found. Our data suggests that CT scan staging correlated poorly with IRUS staging. CT poorly determines depth of rectal tumor wall invasion. IRUS correlated well with pathology and understaged 5 per cent of patients before surgery. Genitourinary abnormalities were detected in a significant number of patients. IRUS is an effective modality for preoperative staging of rectal cancer.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenocarcinoma↗
PubMed1993

Levels of tumor necrosis factor alpha/cachectin (TNF alpha) in sera from patients with sickle cell disease.

Serum levels of tumor necrosis factor alpha/cachectin (TNF alpha) were studied in a group of adult patients with sickle cell disease (SCD), which include 31 patients with homozygous SS hemoglobinopathy and 10 patients bearing double heterozygous SC hemoglobinopathy and in their matched normal controls. All patients tested did not show any form of crisis for at least 4 weeks prior to the extraction of the sample. The amount of TNF alpha in serum was quantitated by means of an immunoenzymatic assay with a lower limit of detection of 25 pg/ml. The percentage of sera with detectable levels of TNF alpha was significantly increased in SCD patients as compared with the normal controls. Mean TNF alpha values in individuals with detectable levels of the cytokine were also significantly higher in the whole group of SCD patients and in patients bearing either SS or SC hemoglobinopathies than in the control group. An inverse correlation was observed between the percentages of Hb F and the levels of TNF alpha found in the sera from the patients.

Adult↗
PubMed1990

In vitro antibody synthesis by peripheral blood mononuclear cells from patients with sickle cell disease.

To study the capacity of peripheral blood mononuclear cells (PBMC) from patients with sickle cell disease to synthesize antibodies in vitro, the levels of IgM, IgG, and IgA were quantitated in supernatants of cultured PBMC from a group of asymptomatic adults with sickle cell disease and from normal controls. The rates of spontaneous synthesis of IgM were similar in nonstimulated cultures of PBMC from patients and controls, whereas the amounts of IgG and IgA produced spontaneously by nonstimulated lymphocytes from the patients were significantly greater than those from controls. Similar levels of IgM, IgG, and IgA were detected in the supernatants of cultures stimulated with pokeweed mitogen from patients and controls. Thus, the capacity of PBMC to respond in vitro to pokeweed mitogen was preserved in the patients. The enhanced spontaneous synthesis of IgG and IgA suggests the presence of chronic polyclonal activation of B cells and/or defective regulation of the production of antibodies.

Anemia, Sickle Cell↗
PubMed1990

[Hemoglobin variants and hematologic and serologic parameters of the population of El Limón (Aragua State, Venezuela)].

Nine hundred and fifty seven individuals from El Limon (Aragua State, Venezuela) were studied, in order to get information on their hematologic, immunologic and biochemical characteristics. The majority of surnames were of Spanish origin although there were also from other European nationalities. No surname from Venezuelan Indians was found. The pathologic hemoglobin variants (Hb S, Hb C and Hb D-Punjab) have a frequency of 4.3%. Eight albumin variants were detected. The hematologic values suggest a high frequency of iron deficiency. Positivity for hepatitis virus B was found in 0.9% of the population. The carriers and patients for hemoglobin variants per generation was calculated for the whole municipality (5062 and 26, respectively). The African component of the population was estimated in around 18%.

Adolescent↗
PubMed1985

Hemoglobin Hofu associated with beta 0-thalassemia.

A mild anemia (hemoglobin 9 g/dl) was found in a patient from Seville (Spain) with marked morphological abnormalities in the peripheral blood smear. The red cell osmotic fragility showed a mild resistance curve with a mean cell fragility (MCF) of 0.375% NaCl (normal = 0.450). Chemical Chemical and thermal instability test and search for inclusion bodies gave positive results. Hemoglobin electrophoresis at pH 8.9 revealed absence of Hb A, a major component of fast mobility (94%), and increased Hb F and Hb A2 levels (1.5% and 4.6%, respectively). The fast fraction, isolated and purified by means of cellulose acetate electrophoresis, precipitated in acid acetone and treated with urea 8 M and mercaptoethanol, revealed an anomalous beta chain. Trypsin-digested globin peptides were separated by high-voltage electrophoresis at pH 6.4 and ascendant chromatography. With differential staining, an extra peptide was detected in an unusual site, more anodic than alpha Tp4 but in lower position. Peptide map of the fast beta chain, stained with ninhydrin, and also for Tyr, confirmed the position of the new peptide and the absence of the usual beta Tp13. The new peptide, separated by high-voltage electrophoresis at pH 3.5, revealed absence of Val and the presence of an additional Glu residue, which should appear only in position beta 126. The diagnosis of Hb Hofu (alpha 2 beta 2 126 Val----Glu; H4) was reached, thus interpreting its increase and the absence of Hb A, as an association with beta o-thalassemia, producing a mild hemolytic anemia. Evidence was obtained that Hb Hofu is a mild unstable hemoglobin variant.

Adult↗
PubMed1982

Chediak-Higashi syndrome: description of a cluster in a Venezuelan-Andean isolated region.

Fourteen cases of the Chediak-Higashi syndrome found in twelve non-related families living in a defined geographical area not larger than 200 km2 of the Tachira State, Venezuela (population of around 72,000 inhabitants) were diagnosed between 1967 and 1974. The patients were pre-school or nursing age children except one eleven year old female. Six of the patients were male. All showed the same typical somatic characteristics of this syndrome. Four cases were 2 pairs of brothers. Consanguinity of the parents was seen in only two families, even though the majority of them come from the same restricted geographic zone (Pregonero). Since this anomaly is supposedly produced by a rare recessive autosomal gene, the existence of its high frequency in a small Venezuelan region may be explained through the "founder effect" in a population with a high inbreeding coefficient.

Chediak-Higashi Syndrome↗
PubMed1980

Foetal and neonatal albumins in bovines: some biochemical and immunochemical properties.

A study is presented of bovine foetal albumin, a serum protein present in newborns less than 15 days old. As a result of the biochemical and immunochemical analyses, and of the comparison carried out with human foetal albumin, it was concluded that: 1) They share certain characteristics, such as molecular weight, behaviour in the presence of reducing agents, and a great affinity for staining agents. 2) Bovine foetal albumin has a slower electrophoretic mobility than that of the corresponding adult albumin, this aspect differentiating it from human foetal albumin which is faster than human adult albumin.

Animals↗
PubMed1976

Pyruvate kinase deficiency and leg ulcers.

We report a family with a new pyruvate kinase (PK) variant in which leg ulcers have been present in four of the five affected homozygous family members, but not in any of the unaffected individuals. The propositus, an 18-yr-old boy, suffered from recurrent crises of hemolytic anemia and leg ulcers. A splenectomy was performed and the leg ulcer was treated un-successfully with a pinch graft. Studies ondialyzed hemolysates showed that the enzyme was kinetically abnorma, being almost entirely resistant to activation by fructose diphosphate. THE THERMOSTABILITY OF THE ENZYME WAS MODERATELY DECREASED, AND THE ELECTROPHORETIC MOBILITY WAS NORMAL. One may speculate that the development of leg ulcers in some kinships with PK deficiency may be related to variants of PK which exert unusual effects on the rheologic properties of the red cell in vivo.

Adolescent↗