Measurement of pepsin in porcine gastric juice

The method for measurement of pepsin in human gastric juice as devised by Anson and modified by Berstad has been used for testing pepsin secretion from Heidenhain pouches in pigs. Twenty samples may be analysed at one time with accuracy. Variations in ambient temperature and humidity, and contamination of samples with bile, were found to interfere with the accuracy of the method. There was no change in activity after immediate freezing at -20°C or after storage at -20°C for up to 3 months. After repeated thawing and refreezing on 4 consecutive days, there was a fall in activity on the fourth day only.S. Afr. Med. J., 48, 1873 (1974)

c-jun is essential for sympathetic neuronal death induced by NGF withdrawal but not by p75 activation.

Sympathetic neurons depend on NGF binding to TrkA for their survival during vertebrate development. NGF deprivation initiates a transcription-dependent apoptotic response, which is suggested to require activation of the transcription factor c-Jun. Similarly, apoptosis can also be induced by selective activation of the p75 neurotrophin receptor. The transcriptional dependency of p75-mediated cell death has not been determined; however, c-Jun NH2-terminal kinase has been implicated as an essential component. Because the c-jun-null mutation is early embryonic lethal, thereby hindering a genetic analysis, we used the Cre-lox system to conditionally delete this gene. Sympathetic neurons isolated from postnatal day 1 c-jun-floxed mice were infected with an adenovirus expressing Cre recombinase or GFP and analyzed for their dependence on NGF for survival. Cre immunopositive neurons survived NGF withdrawal, whereas those expressing GFP or those uninfected underwent apoptosis within 48 h, as determined by DAPI staining. In contrast, brain-derived neurotrophic factor (BDNF) binding to p75 resulted in an equivalent level of apoptosis in neurons expressing Cre, GFP, and uninfected cells. Nevertheless, cycloheximide treatment prevented BDNF-mediated apoptosis. These results indicate that whereas c-jun is required for apoptosis in sympathetic neurons on NGF withdrawal, an alternate signaling pathway must be induced on p75 activation

Entrepreneurial capital, social values and Islamic traditions: exploring the growth of women-owned enterprises in Pakistan

Main ArticleThis study seeks to explore the variables contributing to the growth of women-owned enterprises in the Islamic Republic of Pakistan. Based on a previously established multivariate model, it uses two econometric approaches: first classifying variables into predetermined blocks; and second, using the general to specific approach. Statistical analyses and in-depth interviews confirm that women entrepreneurs’ personal resources and social capital have a significant role in their business growth. Further, it reveals that the moral support of immediate family, independent mobility and being allowed to meet with men play a decisive role in the sales and employment growth of women-owned enterprises in an Islamic country such as Pakistan

Heritability of DNA-damage-induced apoptosis and its relationship with age in lymphocytes from female twins

Apoptosis is a physiological form of cell death important in normal processes such as morphogenesis and the functioning of the immune system. In addition, defects in the apoptotic process play a major role in a number of important areas of disease, such as autoimmune diseases and cancer. DNA-damage-induced apoptosis plays a vital role in the maintenance of genomic stability by the removal of damaged cells. Previous studies of the apoptotic response (AR) to radiation-induced DNA damage of lymphoid cells from individuals carrying germline TP53 mutations have demonstrated a defective AR compared with normal controls. We have also previously demonstrated that AR is reduced as individuals age. Results from the current study on 108 twins aged 18–80 years confirm these earlier findings that the AR of lymphoid cells to DNA damage is significantly reduced with increasing age. In addition this twin study shows, for the first time, that DNA-damage-induced AR has a strong degree of heritability of 81% (95% confidence interval 67–89%). The vital role of DNA-damage-induced apoptosis in maintaining genetic stability, its relationship with age and its strong heritability underline the importance of this area of biology and suggest areas for further study

Post-prandial amino acid changes in gilthead sea bream

Following a meal, a series of physiological changes occurs in fish as they digest, absorb and assimilate ingested nutrients. This study aims to assess post-prandial free amino acid (FAA) activity in gilthead sea bream consuming a partial marine protein (fishmeal) replacement. Sea bream were fed diets where 16 and 27% of the fishmeal protein was replaced by plant protein. The essential amino acid (EAA) composition of the white muscle, liver and gut of sea bream was strongly correlated with the EAA composition of the 16% protein replacement diet compared to the 27% protein replacement diet. The mean FAA concentration in the white muscle and liver changed at 4 to 8 h after a meal and was not different to pre-feeding (0 h) and at 24 h after feeding. It was confirmed in this study that 16% replacement of marine protein with plant protein meets the amino acid needs of sea bream. Overall, the present study contributes towards understanding post-prandial amino acid profiles during uptake, tissue assimilation and immediate metabolic processing of amino acids in sea bream consuming a partial marine protein replacement. This study suggests the need to further investigate the magnitude of the post-prandial tissue-specific amino acid activity in relation to species-specific abilities to regulate metabolism due to dietary nutrient utilization

Femoral bone mesoscale structural architecture prediction using musculoskeletal and finite element modelling

Through much of the anatomical and clinical literature bone is studied with a focus on its structural architecture, while it is rare for bone to be modelled using a structural mechanics as opposed to a continuum mechanics approach in the engineering literature. A novel mesoscale structural model of the femur is presented in which truss and shell elements are used to represent trabecular and cortical bone, respectively. Structural optimisation using a strain-based bone adaptation algorithm is incorporated within a musculoskeletal and finite element modelling framework to predict the structure of the femur subjected to two loading scenarios; a single load case corresponding to the frame of maximum hip joint contact force during walking and a full loading regime consisting of multiple load cases from five activities of daily living. The use of the full loading regime compared to the single load case has a profound influence on the predicted trabecular and cortical structure throughout the femur, with dramatic volume increases in the femoral shaft and the distal femur, and regional increases at the femoral neck and greater trochanter in the proximal femur. The mesoscale structural model subjected to the full loading regime shows agreement with the observed structural architecture of the femur while the structural approach has potential application in bone fracture prediction, prevention and treatment. The mesoscale structural approach achieves the synergistic goals of computational efficiency similar to a macroscale continuum approach and a resolution nearing that of a microscale continuum approach

Imaging-guided chest biopsies: techniques and clinical results

Background This article aims to comprehensively describe indications, contraindications, technical aspects, diagnostic accuracy and complications of percutaneous lung biopsy. Methods Imaging-guided biopsy currently represents one of the predominant methods for obtaining tissue specimens in patients with lung nodules; in many cases treatment protocols are based on histological information; thus, biopsy is frequently performed, when technically feasible, or in case other techniques (such as bronchoscopy with lavage) are inconclusive. Results Although a coaxial system is suitable in any case, two categories of needles can be used: fine-needle aspiration biopsy (FNAB) and core-needle biopsy (CNB), with the latter demonstrated to have a slightly higher overall sensitivity, specificity and accuracy. Conclusion Percutaneous lung biopsy is a safe procedure even though a few complications are possible: pneumothorax, pulmonary haemorrhage and haemoptysis are common complications, while air embolism and seeding are rare, but potentially fatal complications

Pasteurella multocida Heddleston serovar 3 and 4 strains share a common lipopolysaccharide biosynthesis locus but display both inter- and intrastrain lipopolysaccharide heterogeneity

Pasteurella multocida is a Gram-negative multispecies pathogen and the causative agent of fowl cholera, a serious disease of poultry which can present in both acute and chronic forms. The major outer membrane component lipopolysaccharide (LPS) is both an important virulence factor and a major immunogen. Our previous studies determined the LPS structures expressed by different P. multocida strains and revealed that a number of strains belonging to different serovars contain the same LPS biosynthesis locus but express different LPS structures due to mutations within glycosyltransferase genes. In this study, we report the full LPS structure of the serovar 4 type strain, P1662, and reveal that it shares the same LPS outer core biosynthesis locus, L3, with the serovar 3 strains P1059 and Pm70. Using directed mutagenesis, the role of each glycosyltransferase gene in LPS outer core assembly was determined. LPS structural analysis of 23 Australian field isolates that contain the L3 locus revealed that at least six different LPS outer core structures can be produced as a result of mutations within the LPS glycosyltransferase genes. Moreover, some field isolates produce multiple but related LPS glycoforms simultaneously, and three LPS outer core structures are remarkably similar to the globo series of vertebrate glycosphingolipids. Our in-depth analysis showing the genetics and full range of P. multocida lipopolysaccharide structures will facilitate the improvement of typing systems and the prediction of the protective efficacy of vaccines