Acute Isovolemic Anemia Does Not Impair Peripheral or Central Nerve Conduction

Background: Previous studies have found subtle slowing of responses in tests of addition and digit-symbol substitution during acute severe isovolemic anemia to a hemoglobin concentration of 5 g/dl in healthy unmedicated humans. In this study, the authors tested the hypothesis that such changes relate to the slowing of afferent neural traffic.

Methods: The median nerve was stimulated at the wrist in seven healthy unmedicated volunteers before and after induction of acute isovolemic anemia to a nadir hemoglobin concentration of 5.1 +/- 0.3 g/dl (mean +/- SD). Times for neural impulses to travel from the stimulus site to the brachial plexus, cervical spinal cord, and cerebral cortex were measured using somatosensory evoked potentials. Tests were repeated during acute anemia with the subject breathing oxygen. As a control for time and intrasubject variation, the testing was repeated on a separate day when anemia was not produced at times equivalent to those on the experimental day.

Results: Induced acute severe isovolemic anemia decreased nerve conduction latencies from the wrist to the contralateral cerebral cortex (i.e., to the N20 peak) by 2.3 +/- 1.6% compared with values at a mean hemoglobin concentration of 12.7 g/dl (P < 0.01). These decreased latencies were due solely to an increased peripheral conduction velocity, from the wrist to the brachial plexus (P < 0.05), and were not altered when subjects breathed oxygen (P > 0.05). Conduction velocity from the brachial plexus or cervical spinal cord to the cerebral cortex did not change with acute anemia (P > 0.05). Latencies did not differ on the control day among the times of testing (all P > 0.05), nor did they differ at baseline between the control and experimental days (all P > 0.05).     

SURGICAL CORRECTION OF DIPYGUS

Dipygus is a rare malformation.t-3 We en- countered a case in 1980, and it is reported here- with.     

Blocking the insulin-like growth factor-I receptor as a strategy for targeting cancer

Clear links between cancer and cellular signaling triggered by the insulin-like growth factor-I (IGF-I) receptor (IGF-IR) and its cognate ligands (IGF-I and IGF-II) have been reported throughout the past two decades. Experimental results suggest that the pharmaceutical targeting of this signaling pathway could be beneficial for the treatment of cancer. Here, more recent advances towards potentially clinically viable strategies to interfere with the function of IGF-IR will be discussed.     

Seroprevalence of varicella among children and adolescents in Valencia, Spain. Reliability of the parent's reported history and the medical file for identification of potential candidates for vaccination

This study assessed the seroprevalence of varicella antibodies in children and adolescents in Spain and evaluated the reliability of two methods for detecting susceptible individuals: (1) parental-reported history of varicella and (2) medically-documented histories maintained by the pediatrician. A total of 186 children (6 to 15 years of age) were recruited in 13 pediatric offices of Valencia, Spain. A brief case report form was completed including previous history of varicella referred by the parents, and a 5 mL blood sample was obtained. The pediatrician medical file was reviewed for antecedent of varicella. The overall prevalence of varicella antibodies was 84% and 88% in the 6-9 years and 10-15 years age brackets, respectively. The predictive value of a negative history of varicella disease was 48% by parental recall (52% "false negative"), and only 26% by medical record (74% "false negative"). However, the positive predictive value of a positive parental reported history or a positive medically-documented history was 95%. The most effective strategy for varicella vaccination of older children and adolescents in Spain will be to immunize those individuals with a lack of positive (unknown or negative) history of disease.     

Isolation of two plant proteinases in latex from Carica candamarcensis acting as mitogens for mammalian cells

In a prior study we showed evidence that latex from Carica candamarcensis contains a protein fraction that stimulates mammalian cell proliferation. In this report we describe the isolation of two proteinases responsible for this effect. Both proteinases (P1, P2) display a relative mass of 23 kDa and following chromatographic purification stimulate proliferation of fibroblastic and epithelial cells. P2 added to L929 fibroblasts at 2.5 nM enhances proliferation by 60 %. We further demonstrate that its cellular effect is linked to an increase in activity of Erk2, a component of the MAP kinase pathway. To our knowledge, this is the first known plant proteinase to exert a proliferative effect in mammalian cells. This novel mitogenic property attributed to a purified cysteine proteinase may explain some of the therapeutic actions attributed to these enzymes.     

5-HT<Subscript>1A</Subscript> receptor expression during memory formation

Rationale It has been reported that 5-HT_1A receptors modulate learning and memory and diverse pharmacological and genetic evidence supports this notion. Nevertheless, there are few works about expression of these receptors during memory formation. Objective We aimed to determine 5-HT_1A receptor expression in brain areas of untrained, passive, and autoshaping trained groups of rats. Methods Ex vivo receptor autoradiography using the ligand agonist [³H]8-hydroxy-2-[di-n-propylamino]tetralin] (8-OH-DPAT) was used. Results The trained group relative to untrained animals showed increases of 5-HT_1A receptor expression in 14 brain areas, decrements in 7, and no changes in 12. Thus, in contrast to untrained rats, 5-HT_1A receptor expression of autoshaping trained rats was augmented in the tubercule olfactory, septal nucleus, nucleus accumbens, caudate putamen, globus pallidus, striate, and parietal (1 and 2), temporal cortex (1 and 3), granular retrosplenial cortex (1), amygdala, and median and dorsal raphe nuclei. In contrast, in the latter group, receptors were decreased in the CA1 area, hypothalamus dorsal, frontal cortex (1 and 3), occipital cortex, cingulate cortex (1 and 2), and cuneiform nucleus. There were significant differences between passive vs trained groups, but not regarding untrained rats, in the lateral olfactory tract, dentate gyrus, CA3 area, ventromedial hypothalamic, lateral hypothalamus, preoptic medial, frontal cortex (2), granular retrosplenial cortex (2), entorhinal cortex (1 and 2), piriform cortex, and substantia nigra. Conclusions These data suggest that upregulated, downregulated, and “silence” of 5-HT_1A receptors in brain areas form part of neural circuits engaged in memory formation by demonstrating a high degree of specificity and memory mapping.     

Expression of pendrin in benign and malignant human thyroid tissues

The Pendred syndrome gene (PDS) encodes a transmembrane protein, pendrin, which is expressed in follicular thyroid cells and participates in the apical iodide transport. Pendrin expression has been studied in various thyroid neoplasms by means of immunohistochemistry (IHC), Western blot and RT-quantitative real-time PCR. The expression was related to the functional activity of the thyroid tissue. Follicular cells of normal, nodular goitre and Graves' disease tissues express pendrin at the apical pole of the thyrocytes. In follicular adenomas, pendrin was detected in cell membranes and cytoplasm simultaneously in 10 out of 15 cases. Pendrin protein was detected in 73.3 and 76.7% of the follicular (FTC) and papillary (PTC) thyroid carcinomas, respectively, where pendrin was solely localised inside the cytoplasm. An extensive intracellular immunostaining of pendrin was observed in six out of 11 (54.5%) of positive FTCs and 19 out of 23 (82%) of PTCs. Focal reactivity was detected in one follicular- and three papillary carcinomas, whereas pendrin protein was absent in three of 15 FTC and four of 30 PTC; mRNA of pendrin was detected in 92.4% of thyroid tumours. The relative mRNA expression of pendrin was lower in cancers than in normal thyroid tissues (P<0.001). The pendrin protein level was found to parallel its mRNA expression, which was not, however, related to the tumour size and tumour stage. In conclusion, pendrin is expressed in the majority of differentiated thyroid tumours with high individual variability but its targeting to the apical cell membrane is affected.     

Detection of JC virus DNA sequences and expression of viral T antigen and agnoprotein in esophageal carcinoma

BACKGROUND: The human polyomavirus JC virus (JCV) causes progressive multifocal leukoencephalopathy. Subclinical infection with JCV occurs in 85-90% of the population worldwide. The virus usually remains latent but can reactivate under immunosuppressive conditions, resulting in progressive multifocal leukoencephalopathy. JCV is oncogenic in experimental animals and is associated with human brain tumors. JCV is found in normal mucosa of the gastrointestinal tract, and some colon carcinomas express the oncogenic JCV T-antigen protein. The objective of this study was to examine the presence of JCV DNA sequences and JCV protein expression in normal and malignant human esophageal tissues. METHODS: The authors examined the presence of JCV DNA sequences and protein expression in normal and malignant human esophageal tissues. Seventy well characterized biopsy specimens from patients with a spectrum of esophageal disorders were studied by immunohistochemistry, and 18 specimens were analyzed further by polymerase chain reaction amplification. RESULTS: JC viral DNA was isolated from 11 of 13 normal esophageal biopsy specimens (85%) and from 5 of 5 esophageal carcinomas (100%). Using immunohistochemistry, JCV T antigen was detected in 10 of 19 carcinomas (53%), agnoprotein was detected in 8 carcinomas (42%), p53 tumor suppressor was detected in 11 carcinomas (58%), and beta-catenin was detected in 4 carcinomas (21%). Zero of 51 normal, benign, and premalignant esophageal samples expressed viral proteins. Laser-capture microdissection verified the presence and specificity of JCV DNA sequences. beta-Catenin and p53 were colocalized with JCV T-antigen in the nuclei of neoplastic cells. CONCLUSIONS: The results provide evidence for infection of gastrointestinal tract cells by JCV and suggest a potential role of JCV in the development of upper digestive tract carcinomas.     

Influenza in Poland in 2003

Following two years of low influenza incidence in Poland, the activity of this disease markedly increased in 2003. In total 1,216,285 cases of influenza like illness were registered (incidence 3,184.4 per 100,000). Regionally the incidence ranged from 1,195.7 in Zachodniopomorskie to 5,719.7 per 100,000 in Mazowieckie. Children and adolescents under 15 years of age accounted for 41.7% of all cases (507,102 cases, age specific incidence 7,579.0 per 100,000). In this age group the incidence varied regionally from 2,718.1 in Podlaskie to 14,087.6 per 100,000 in Mazowieckie. 3,128 patients (0.26% of all cases) required hospital admission. There were 141 deaths due to influenza (mortality 0.12%) in 2003, in 78.7% these were persons over 70 years of age. Nineteen strains of influenza virus were isolated in 2003 in Poland, including 15 strains of subtype A(H3), 3 strains of subtype A(H1) and one strain of type B. Besides, in other 10 cases influenza A infection was confirmed by direct immunofluorescence test. All isolated influenza strains were antigenically similar to the vaccine strains recommended for the epidemic season 2002/03 and 2003/04.