Diagnostic performance of arginase activity in colorectal cancer

Arginase activity was measured in serum and biopsy from healthy individuals and colorectal cancer patients. Arginase activity in tumor samples (87±7.7 U/g tissue) was significantly higher than in controls (40.7±3.3 U/g tissue). However, serum arginase activity did not show any significant change in both groups. Finally, the micromethod used to quantify arginase activity in this study is superior to other methods because it has increased sensitivity, requires less sample, and is less time-consuming. Arginase differences are significant, according to the t-test (P<0.05). Received: 14 September 2001 / Accepted: 6 February 2002     

Orbital meningioma with a granular cell component in a dog, with extracranial metastasis

A meningioma with a significant component of granular cells is described in the left ocular orbit of a 5-year-old male Golden retriever dog that presented with exophthalmos. The neoplastic mass surrounded the optic nerve. Microscopically, the tumour was characterized by nests of large, round to polygonal cells, variable in size, with eccentric nuclei and abundant eosinophilic cytoplasm, containing PAS-positive granules. In focal areas, cells were smaller and occasionally formed whorl-like structures. Immunohistochemical analysis revealed that neoplastic cells reacted positively for vimentin and, with less intensity, for neuron specific enolase and S-100, whereas they were negative for glial fibrillary acidic protein and cytokeratins. Metastatic growths, formed by similar cells, were seen in the lung and heart.     

Multivariate Base Rates of Low Scores on Tests of Learning and Memory among Spanish-Speaking Children

ABSTRACT

To determine the prevalence of low scores on two neuropsychological tests commonly used to evaluate learning and memory in children. 6,030 healthy children from 10 countries in Latin America and Spain were administered Rey–Osterrieth Complex Figure (ROCF) and the Test de Aprendizaje y Memoria Verbal–Infantil (TAMV-I). Results showed that low scores are common when multiple neuropsychological outcomes (tests and/or scores) are evaluated in healthy individuals. Clinicians should consider the higher probability of low scores in a given individual when evaluating learning and memory using various sets of scores to reduce false-positive diagnoses of cognitive deficits in pediatric populations.     

Lactate and pyruvate increase the incorporation of [3H]proline into collagen [3H]hydroxyproline in liver slices of CCl4 cirrhotic rats

Lactate and pyruvate enhanced the incorporation of [3H]proline into collagen [3H]hydroxyproline when added to liver slices of CCl4-treated rats. In addition, pyruvate stimulated the accumulation of cAMP, reaching maximum values after 10 minutes of incubation. Similar results were obtained with newborn rat calvariae, a tissue that normally produces large amounts of type I collagen. In normal liver, which produces relatively small amounts of collagen, lactate had no effect on cAMP levels or collagen synthesis. Pyruvate stimulated the accumulation of cAMP, but had no effect on collagen synthesis. These results indicate that different control mechanisms are involved in regulation of collagen biosynthesis in normal as compared with cirrhotic liver; the latter resembling mesenchymal tissues specialized in collagen production such as newborn rat calvariae.     

Skin collagen changes related to age and hormone replacement therapy.

A total of 76 nulliparous women who had been hospitalized for minor operations, classified according to age group (by decade from 20s to 60s) and 118 postmenopausal women randomly allocated to one of four groups were studied. In all, 312 skin biopsies were taken from the lower abdomen at 0 and 12 months and the skin collagen changes noted. Collagen content decreased significantly with age beyond the 40s (P < 0.001) and after the menopause (P < 0.01). The decrease was preventable by the use of hormone replacement therapy. All the therapeutic regimens induced increases in skin collagen content, whereas in the control group a significant decrease was observed (P < 0.05).     

Poly(Glu60Ala30Tyr10) (GAT)-induced IgG monoclonal antibodies cross-react with various self and non-self antigens through the complementarity determining regions. Comparison with IgM monoclonal polyreactive natural antibodies

Previous studies have shown that the antibodies of the preimmune repertoire are able to bind to various auto- and xenoantigens including chemical haptens. Sequence analysis of two such murine monoclonal IgM natural autoantibodies showed that they are encoded by unmutated germ-line variable regions of the light and heavy chain (V alpha and VH) genes which were also found in various murine immune responses, like phenyl-oxazolone, dinitrophenyl, arsonate, phosphorylcholine and influenza virus hemagglutinin. These data raised the question as to whether induced antibodies possessing germ-line sequence are also able to react with autoantigens. To study this problem, anti-poly(Glu60Ala30Tyr10) (GAT) and anti-alprenolol (Alp) monoclonal antibodies, carrying similar VH and V alpha genes and the same IgG1 isotype, were examined for their capacity to react with several self and non-self antigens. The results showed that: (a) the anti-GAT antibodies tested reacted with different autoantigens, such as murine tubulin, actin and myosin as well as trinitrophenyl (TNP) and bovine serum albumin. Similarly, one of the anti-Alp showed weak reactivities for myosin, DNA, actin and TNP; (b) in contrast two other anti-Alp antibodies did not react with any of the tested antigens. Since the major differences between the oligoreactive anti-GAT and the monoreactive anti-Alp antibodies are in the complementarity determining regions (CDR) our results suggest that the observed cross-reactions are mediated by hypervariable loops. Sequence comparison of these antibodies indicate a possible correlation between cross-reactivity and the presence of aromatic and charged amino acids in the CDR.     

A chromosome No. 2 abnormality in a child with a few congenital defects*

An abnormal chromosome No. 2 was found in the case of a child with an imperforate anus, a recto-vaginal fistula, unilateral atresia of the inner canal, and deformity of the external ear. G-banding studies revealed an insertion of a segment of the short arm into the long arm in one of the chromosomes No. 2 of the proband, the apparent result of a de novo phenomenon of chromosome rearrangement.