Transforming growth factor alpha with insulin stimulates cell proliferation in vivo in adult rat vestibular sensory epithelium

Hair cells, the sensory receptors of the mammalian inner ear, have long been thought to be produced only during embryogenesis, and postnatal hair cell loss is considered to be irreversible and is associated with permanent hearing and balance deficits. Little is known about the factors that regulate hair cell genesis and differentiation. The mitogenic effects of insulin and transforming growth factor alpha (TGFalpha) were assayed in vivo in normal and drug-damaged rat inner ear. Tritiated thymidine and autoradiographic techniques were used to identify cells synthesizing DNA. Simultaneous infusion of TGFalpha and insulin directly into the inner ear of adult rats stimulated DNA synthesis in the vestibular sensory receptor epithelium. New supporting cells and putative new hair cells were produced. Infusion of insulin alone or TGFalpha alone failed to stimulate significant DNA synthesis. These results suggest that exogenous growth factors may have utility for therapeutic treatment of hearing and balance disorders in vivo.     

Evidence that the Rad1 and Rad10 proteins of Saccharomyces cerevisiae participate as a complex in nucleotide excision repair of UV radiation damage

A newly characterized rad1 missense mutation (rad1-20) in the yeast Saccharomyces cerevisiae maps to a region of the Rad1 polypeptide known to be required for Rad1-Rad10 complex formation. The UV sensitivity of the rad1-20 mutant can be partially and specifically corrected by overexpression of wild-type Rad10 protein. These results suggest that complex formation between the Rad1 and Rad10 proteins is required for nucleotide excision repair.     

Pain-related cerebral potentials in response to acute painful electrical stimulation in sheep

OBJECTIVE: To examine associations between late event-related cerebral potential amplitudes and behavioural responses to noxious electrical stimulation as an indicator of acute pain in sheep. DESIGN: Analysis of variance for the effects of stimulus intensity on the behaviour and event-related cerebral potential variables. PROCEDURE: Ninety-six brief constant current electrical pulse trains were presented to the front left leg of eight sheep at four intensities (2.5 to 10 mA) in a randomised order. An event-related cerebral potential and a graded flinch response were recorded for each stimulus and the 24 event-related cerebral potentials at each intensity were averaged to produce a mean waveform. Various components of this waveform were analysed and changes in these measures and the sheep's flinch response, as stimulus intensity increased, were determined. RESULTS: Both the flinch response and some event-related cerebral potential components, that is, peak amplitudes 114 [N1], 187 [P1], 318 [P2] and 230 [Pm] ms after stimulus onset, were significantly affected as stimulus intensity increased. CONCLUSION: These corresponding behavioural and event-related cerebral potential changes indicate the usefulness of using changes in the event-related cerebral potential to measure acute pain in sheep.     

Hydrolysis of gamma:epsilon isopeptides by cytosolic transglutaminases and by coagulation factor XIIIa

Nepsilon-(gamma-glutamyl)lysine cross-links, connecting various peptide chain segments, are frequently the major products in transglutaminase-catalyzed reactions. We have now investigated the effectiveness of these enzymes for hydrolyzing the gamma:epsilon linkage. Branched compounds were synthesized, in which the backbone on the gamma-side of the cross-bridge was labeled with a fluorophor (5-(dimethylamino)-1-naphthalenesulfonyl or 2-aminobenzoyl) attached through an epsilon-aminocaproyl linker in the N-terminal position, and the other branch of the bridge was constructed with Lys methylamide or diaminopentane blocked by 2,4-dinitrophenyl at the Nalpha position. Hydrolysis of the cross-link could be followed in these internally quenched substrates by an increase in fluorescence. In addition to the thrombin and Ca2+-activated human coagulation Factor XIIIa, cytosolic transglutaminases from human red cells and from guinea pig liver were tested. All three enzymes were found to display good isopeptidase activities, with Km values of 10(-4) to 10(-5) M. Inhibitors of transamidation were effective in blocking the hydrolysis by the enzymes, indicating that expression of isopeptidase activity did not require unusual protein conformations. We suggest that transglutaminases may play a dynamic role in biology not only by promoting the formation but also the breaking of Nepsilon-(gamma-glutamyl)lysine isopeptides.     

Two-dimensional electrophoretic analysis of membranous protein from human thyroid tissues and cancer cell lines

Thyroid neoplasm is the most commonly encountered neoplastic disorder in endocrine clinics. Thyroid scan, ultrasonography, and fine needle aspiration cytology (FNAC) are used as diagnostic tools to differentiate a malignant nodule from a benign lesion. There are certain limitations and pitfalls in FNAC, especially in the diagnosing of follicular tumors. The lack of characteristic findings or a specific tumor marker are the most common problems in the preoperative diagnosis of thyroid follicular carcinoma. Although serum thyroglobulin level has been used as a tumor marker for post-operative, well-differentiated thyroid cancer, the assay cannot be used for preoperative diagnosis of thyroid carcinoma. In this study, various thyroid tissues and cancer cell lines including CGTH W-1, CGTH W-3, RO 82 W-1, SW 579 cell lines were used for the investigation of tumor markers. Specific spots were identified in the area near the 60 kDa molecular mass protein and isoelectric point (pI) 5.9 of the CGTH W-1 cell line. These spots could not be found in the papillary or anaplastic thyroid cancer cell lines. Another spot with a molecular weight of about 9.8 kDa with a low pI of 4.8 was present in the CGTH W-1 and RO 82 W-1 cell lines. This spot appeared to be a tumor marker of follicular cancer cells. This spot could not be found in the papillary and anaplastic cancer cell lines and other benign thyroid tissues. Specific proteins that were identified in this study may be useful as tumor markers for follicular thyroid carcinoma.     

Crystal structure of the actin-binding protein actophorin from Acanthamoeba

Tertiary butyl alcohol and trichloroacetic acid are known to be contaminants in drinking water. In order to evaluate the interactive toxicity of t-butyl alcohol with trichloroacetic acid, young male Wistar rats were dosed through water at a dose level of t-butyl alcohol (TBA)-0.5% (v/v), trichloroacetic acid (TCA)-25 ppm and a combined dose of TBA + TCA (0.5% v/v TBA-25 ppm TCA) for a period of 10 weeks ad libitum and were maintained on normal diet. The control animals received plain water and normal diet. The liver and kidney histology was undertaken to see whether subtoxic administration of TBA and TCA individually as well as combined administration for a period of 10 weeks would bring about any histological alterations. It was observed that TBA, TCA and TBA + TCA caused histological alterations in the liver such as centrilobular necrosis, vacuolation in hepatocytes and loss of hepatic architecture. TBA and TBA + TCA caused periportal proliferation and lymphocytic infiltration. Hypertrophy of hepatocytes in the periportal area was a characteristic feature in the liver of TCA treated rats. Moreover, in the histology of the kidney, in the three treated groups, degeneration of renal tubules, with syncitial arrangements of the nucleus of renal tubular epithelial cells was evident. In addition to this, degeneration of the basement membrane of the Bowmans capsule, diffused glomeruli and vacuolation of glomeruli was also evident in the three treated rat kidneys. Renal tubular proliferation in certain areas was also evident in certain areas of the kidney in TCA treated rats. The results indicate that, TBA and TCA do bring about alterations in histology of liver and kidney, but on combined administration, do not show enhanced toxicity in the form of increased hepatic and renal injury.     

Unreliability of the infrared tympanic thermometer in clinical practice: a comparative study with oral mercury and oral electronic thermometers

BACKGROUND: This study was designed to determine the magnitude and frequency of measurement errors with infrared tympanic thermometers in the clinical setting. METHODS: In a convenience sample of 137 adult inpatients, we compared body temperatures measured by a Diatek 9000 Infrared Aural Thermometer and an IVAC 2090 CoreCheck Tympanic Thermometer between themselves, in right versus left ears, and against concurrently measured oral temperatures using both an electronic thermoprobe and conventional glass mercury thermometer. RESULTS: There was a significant between-brand difference of 0.6 degrees C (IVAC 相似文献   

Complementary surgical/interventional techniques for nonresective management of "inoperable" aneurysms: a second look

A review of the studies of the caries prevalence and periodontal health of patients with cleft lip and palate (CLP) revealed that only five investigations of caries prevalence in CLP patients included children. One reported that CLP children did not have a higher caries prevalence in the permanent dentition, whereas more recent studies have reported a higher caries prevalence in both the primary and permanent dentitions of CLP children than in those of noncleft children. However, there is wide variation in the teeth examined and the method of presenting data on caries prevalence. Six papers have reported on the periodontal health of adult CLP patients, and only one has done so on that of children. The adult CLP patients had poorer oral hygiene and more gingivitis, but there is no conclusive evidence that they have a higher risk of developing periodontal disease. No data on the oral hygiene of CLP children were available, but it has been emphasized that they have significantly more gingivitis than noncleft children, especially in the maxillary anterior teeth.