Relationship between DNA synthesis and growth factor expression in primary cultures of adult rat hepatocytes

In this study we employed primary culture of adult rat hepatocytes to verify the effects of two different extracellular matrices (collagen, matrigel) on EGF-stimulated DNA synthesis and c-myc expression. Our results confirm that in adult rat hepatocytes EGF induces DNA synthesis, preceded by a transient increase of c-myc expression, when cells are cultured at low density on collagen. DNA synthesis appears to be in reciprocal relationship with hepatic expression of IGF-I, IGFBP-1, IGFBP-2 and IGFBP-4, suggesting that IGF-I/IGFBPs system is not involved in liver growth.     

Prediction of occult neck metastases in laryngeal carcinoma: role of proliferating cell nuclear antigen, MIB-1, and E-cadherin immunohistochemical determination

The aim of this study is to investigate the predictive value of proliferative activity assessment and E-cadherin expression by means of immunohistochemistry in identifying patients with laryngeal squamous cell carcinoma at a high risk for occult node metastasis. Thirty consecutive patients treated for laryngeal carcinoma with false clinically negative nodes (occult metastases, pN+) between the years 1980 and 1990 were selected for this study. A group of 30 cases with negative cervical lymph nodes (pN-) having a similar anatomic site and tumor size distribution was used as control. In each case, several histological parameters, including grade, pattern of invasion, number of mitosis (x10 high-power field), tumor inflammatory infiltrate, and tumor sclerosis, were assessed. Proliferative activity was determined using immunohistochemical staining for proliferating cell nuclear antigen (PCNA) and MIB-1. Other putative prognostic factors investigated at the immunohistochemical level were the cell adhesion molecule E-cadherin and two oncoproteins, p53 and c-erbB-2. In pN+ cases, the expression of PCNA and MIB-1 was significantly higher than in the pN- group. Moreover, a significant loss of E-cadherin expression was observed in carcinomas with occult metastases. No differences in p53 and c-erbB-2 oncoproteins were found between pN+ and pN- cases. Among the other pathological parameters examined, only histological grade was significantly associated with the presence of occult metastases, but on multivariate analysis, this relationship was lost. We conclude that PCNA, MIB-1, and E-cadherin are independent predictors of occult nodal disease in laryngeal squamous cell carcinoma, and their immunohistochemical determination could be useful in identifying patients with clinically negative lymph nodes who are at considerable risk for occult metastases and who may benefit from elective neck dissection.     

Dorsal hippocampal lesions impair blocking but not latent inhibition of taste aversion learning in rats.

The aim of the present experiments was to study the effect of nonselective electrolytic lesions of the rat dorsal hippocampus on 2 learning phenomena: the L. J. Kamin (1969) blocking effect and latent inhibition of taste aversion learning. Bilateral dorsal hippocampal lesions selectively impaired blocking induced by 1 saccharin-lithium chloride pairing previous to 1 serial compound (saccharin–cider vinegar)–lithium pairing, but lesions had no effect on latent inhibition of a saline aversion, induced by 6 saline preexposures, in the same group of animals. Moreover, dorsal hippocampal lesions did not affect latent inhibition of saccharin-conditioned aversion induced by 1 or 6 preexposures. It is argued that blocking and latent inhibition of taste aversion learning do not share a common neural mechanism. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Allopregnanolone concentration in hippocampus of prepubertal rats and female rats throughout estrous cycle

Hippocampus plays an important role in cognition, neuroendocrine function and sexual behaviour. Changes of hippocampal neuropeptide and neurotransmitter concentrations are associated to behavioural changes occurring throughout reproductive life. The present study focused the attention on the presence of a neurosteroid, 5 alpha-pregnan-3 alpha-ol-20-one (termed allopregnanolone) in hippocampus. In particular, hippocampal allopregnanolone concentration in male and female prepubertal rats and in female rats throughout estrous cycle were evaluated. Hippocampal extracts were eluted on high pressure liquid chromatography and allopregnanolone concentration was measured by radioimmunoassay. Prepubertal male and female rats (15 days old) showed highest values which significantly decreased with advancing age (25 and 60 days) (p < 0.01); the lowest hippocampal concentration of allopregnanolone was found in adult rats. Female rats on proestrus morning and afternoon showed an hippocampal allopregnanolone concentration significantly higher than on diestrus or on estrus (p < 0.01), while rats on estrus showed hippocampal allopregnanolone concentration significantly lower than during other days of estrus cycle (p < 0.01). These data indicate differences in hippocampal concentration of allopregnanolone between prepubertal and adult rats and throughout estrous cycle in female rats. This finding suggest a putative role of neurosteroids in the modulation of behavioral changes occurring throughout reproductive life.     

Parametric Study of Ozone Generation by Coronas

It is shown that previous data on the ozone generation rate by dc coronas can be described by a simple model employing the following concepts. 1) The ozone generation rate is proportional to the electrical power dissipated in the ionization sheath surrounding the wire. 2) The voltage drop across the ionization sheath is proportional to the corona threshold voltage and independent of both the applied voltage and the corona current.     

Statistical Evaluation of the Results Obtained with the Analytical Methods used for the Quality Control of Medicines

To improve the way by which the quality control of medicines is carried out, general statistical concepts and methods are discussed for the evaluation of the analytical results obtained for judging the adequacy of drug substances and products for Pharmacopoeia requirements.

Statistical procedures to be adopted by the producer and the controller in the determination of characteristics are suggested when the drug substance is or is not homogeneous and when the precision of the analytical method is known or unknown.

For each of these cases, detailed numerical examples are given.     

Effects of recombinant bovine somatotropin on nutritional status of dairy cows during pregnancy and of their calves

Objectives of this trial were to evaluate effects of rbST on the nutritional status of 24 Holstein cows during pregnancy and of their calves from birth to weaning. All cows conceived during injection with either a placebo or 350 mg of rbST in a sustained-release vehicle every 14 d commencing 98 to 112 d postpartum for their entire lactation. In Experiment 1, blood samples were collected at 90, 180, and 270 d postconception in cows. Concentrations of urea, glucose, albumin, total proteins, Ca, P, insulin, cortisol, hemoglobin, and hematocrit were unaffected by treatment as well as BW, body condition scores, and energy balances at conception and during pregnancy. Days open and calving interval were not significantly different but were numerically increased by 31 d in rbST-injected cows. Nonesterified fatty acids, bST, and insulin-like growth factor-I in plasma were elevated significantly in rbST-injected cows. In Experiment 2, blood samples were collected at birth and at 1, 3, 5, and 7 wk in calves born from cows of Experiment 1. Circulating concentrations of glucose, nonesterified fatty acids, albumin, total proteins, hemoglobin, insulin, cortisol, bST, insulin-like growth factor-I, and hematocrit, blood pH, blood gases and buffer capacity, birth weight and rate of weight gain, height at withers, and heart girth from birth to weaning were not different due to treatment of dam. However, some parameters were significantly different based on age and sex. These data support previous assumptions that the magnitude of the modifications in nutrient partitioning produced by rbST do not affect the hierarchy of the partitioning process for the calf.     

A procedure to prove statements in differential geometry

An algorithm for theorem proving in differential geometry based on the calculation of the differential dimension of differential quasi-algebraic sets is shown. In the case in which only ordinary differential equations are involved, an algorithm for such computation is presented. Different notions of validity for differential geometry statements are also compared.This paper was supported by Italian M.P.I. (40% 1985).     

Retrieval monitoring and anosognosia in Alzheimer's disease.

This study explored the relationship between episodic memory and anosognosia (a lack of deficit awareness) among patients with mild Alzheimer's disease (AD). Participants studied words and pictures for subsequent memory tests. Healthy older adults made fewer false recognition errors when trying to remember pictures compared with words, suggesting that the perceptual distinctiveness of picture memories enhanced retrieval monitoring (the distinctiveness heuristic). In contrast, although participants with AD could discriminate between studied and nonstudied items, they had difficulty recollecting the specific presentation formats (words or pictures), and they had limited use of the distinctiveness heuristic. Critically, the demands of the memory test modulated the relationship between memory accuracy and anosognosia. Greater anosognosia was associated with impaired memory accuracy when participants with AD tried to remember words but not when they tried to remember pictures. These data further delineate the retrieval monitoring difficulties among individuals with AD and suggest that anosognosia measures are most likely to correlate with memory tests that require the effortful retrieval of nondistinctive information. (PsycINFO Database Record (c) 2010 APA, all rights reserved)