Survival Rate and Enzyme Activities ofLactobacillus acidophilusFollowing Frozen Storage

The ability of two strains of Lactobacillus acidophilus, CRL 640 and CRL 800, to survive and retain their biological activities under frozen storage was determined. Freezing and thawing, as well as frozen storage, damaged the cell membrane, rendering the microorganisms sensitive to sodium chloride and bile salts. Both lactic acid production and proteolytic activity were depressed after 21 days at -20 degreesC, whereas beta-galactosidase activity per cell unit was increased. Cell injury was partially overcome after repair in a salt-rich medium. Copyright 1998 Academic Press.     

A proteomic approach to investigate the distribution and abundance of surface and internal Fasciola hepatica proteins during the chronic stage of natural liver fluke infection in cattle

Fasciola hepatica, a trematode helminth, causes an economically important disease (fasciolosis) in ruminants worldwide. Proteomic analysis of the parasite provides valuable information to understand the relationship between the parasite and its host. Previous studies have identified various parasite proteins, some of which are considered as vaccine candidates or important drug targets. However, the approximate distribution and abundance of the proteins on the surface and within internal parts of the liver fluke are unknown. In this study, two fractions including surface protein fraction (representing surface part of the parasite, near subplasma membrane of the tegument and above the basal membrane of the tegument) and internal protein fraction (representing internal part of the parasite, mainly deeper sides of the tegument including subbasal membrane and other further internal elements of the parasite) were obtained. Components of these two fractions were investigated by an advanced proteomics approach using a high-definition mass spectrometer with nano electrospray ionization source coupled to a high-performance liquid chromatography system (nanoUPLC-ESI-qTOF-MS). FABP1 was found highly abundant in the SPF fraction. Potentially novel F. hepatica proteins showing homology with AKT interacting protein (Xenopus tropicalis), sterol O-acyltransferase 2 (Homo sapiens), and integrin beta 7 (Mus musculus) were identified with high quantities in only the surface fraction of the parasite and may be possible candidates for future control strategies.     

TNF-α is associated with loss of lean body mass only in already cachectic COPD patients

Background

Systemic inflammation may contribute to cachexia in patients with chronic obstructive pulmonary disease (COPD). In this longitudinal study we assessed the association between circulating C-reactive protein (CRP), tumor necrosis factor (TNF)-α, interleukin (IL)-1ß, and IL-6 levels and subsequent loss of fat free mass and fat mass in more than 400 COPD patients over three years.

Methods

The patients, aged 40–76, GOLD stage II-IV, were enrolled in 2006/07, and followed annually. Fat free mass and fat mass indexes (FFMI & FMI) were calculated using bioelectrical impedance, and CRP, TNF-α, IL-1ß, and IL-6 were measured using enzyme immunoassays. Associations with mean change in FFMI and FMI of the four inflammatory plasma markers, sex, age, smoking, FEV₁, inhaled steroids, arterial hypoxemia, and Charlson comorbidity score were analyzed with linear mixed models.

Results

At baseline, only CRP was significantly (but weakly) associated with FFMI (r = 0.18, p < 0.01) and FMI (r = 0.27, p < 0.01). Univariately, higher age, lower FEV₁, and use of beta2-agonists were the only significant predictors of decline in FFMI, whereas smoking, hypoxemia, Charlson score, and use of inhaled steroids predicted increased loss in FMI. Multivariately, high levels of TNF-α (but not CRP, IL-1ß or IL-6) significantly predicted loss of FFMI, however only in patients with established cachexia at entry.

Conclusion

This study does not support the hypothesis that systemic inflammation is the cause of accelerated loss of fat free mass in COPD patients, but suggests a role for TNF-α in already cachectic COPD patients.     

On the application of active learning and Gaussian processes in postcryopreservation cell membrane integrity experiments

Biological cell cryopreservation permits storage of specimens for future use. Stem cell cryostorage in particular is fast becoming a broadly spread practice due to their potential for use in regenerative medicine. For the optimal cryopreservation process, ultralow temperatures are needed. However, elevated temperatures are often unavoidable in a typical sample handling cycle which in turn negatively affects the postcryopreservation integrity of cells. In this paper, we present an application of active learning using an underlying Gaussian Process (GP) model in an experimental study on postcryopreservation membrane integrity response to a range of elevated temperature conditions. We tailored this technique for the current investigation and developed an algorithm which enabled identification of the sampling locations for the experiments in order to obtain the highest information return about the process from a limited size sample set. We applied this algorithm in the experimental study investigating the effects of severe temperature elevation (ranging from -40 to 20 °C) over a short term event (48 hours) on the postcryopreservation membrane integrity of Mesenchymal Stem Cells (MSCs) derived from human bone marrow. The algorithm showed excellent performance by selecting the locations which maximized the reduction of variance of the process response estimate. An approximating GP model developed from this experimental data shows that the elevated temperatures during cryopreservation have an imminent detrimental effect on cell integrity.     

Large, rapidly evolving intergenic spacers in the mitochondrial DNA of the salamander family Ambystomatidae (Amphibia: Caudata)

We report the presence, in the mitochondrial DNA (mtDNA) of all of the sexual species of the salamander family Ambystomatidae, of a shared 240- bp intergenic spacer between tRNAThr and tRNAPro. We place the intergenic spacer in context by presenting the sequence of 1,746 bp of mtDNA from Ambystoma tigrinum tigrinum, describe the nucleotide composition of the intergenic spacer in all of the species of Ambystomatidae, and compare it to other coding and noncoding regions of Ambystoma and several other vertebrate mtDNAs. The nucleotide substitution rate of the intergenic spacer is approximately three times faster than the substitution rate of the control region, as shown by comparisons among six Ambystoma macrodactylum sequences and eight members of the Ambystoma tigrinum complex. We also found additional inserts within the intergenic spacers of five species that varied from 87-444 bp in length. The presence of the intergenic spacer in all sexual species of Ambystomatidae suggests that it arose at least 20 MYA and has been a stable component of the ambystomatid mtDNA ever since. As such, it represents one of the few examples of a large and persistent intergenic spacer in the mtDNA of any vertebrate clade.      

Study of Dyspepsia in a General Practice as Assessed by Endoscopy and Radiology

Fifty consecutive patients presenting in a general practice with dyspepsia were studied. Each patient was referred for a combined barium-meal examination and cholecystogram, followed by fibreoptic endoscopy of the oesophagus, stomach, and duodenum. Thirty patients had a specific lesion of the upper digestive tract and a further four had gall-bladder disease; of these, 16 required surgical treatment. Endoscopy in the remaining 16 patients showed nine with mucosal abnormalities, leaving only seven patients to be classified as normal.The advantage of having an endoscopy service to supplement radiological investigation of dyspepsia is shown.     

Contrasting effects of GPS device and harness attachment on adult survival of Lesser Black‐backed Gulls Larus fuscus and Great Skuas Stercorarius skua

Telemetry has become an important method for studying the biology and ecology of animals. However, the impact of tracking devices and their method of attachment on different species across multiple temporal scales has seldom been assessed. We compared the behavioural and demographic responses of two species of seabird, Lesser Black‐backed Gull Larus fuscus and Great Skua Stercorarius skua, to a GPS device attached using a crossover wing harness. We used telemetry information and monitoring of breeding colonies to compare birds equipped with a device and harness, and control birds without an attachment. We assessed whether tagged birds have lower short‐term breeding productivity or lower longer term overwinter return rates (indicative of overwinter survival) than controls. For Great Skua, we also assessed whether territory attendance within the breeding season differed between tagged and control birds. As with previous studies on Lesser Black‐backed Gull, we found no short‐term impacts on breeding productivity or long‐term impacts on overwinter return rates. For Great Skua, there was no evidence for impacts of the device and harness on territory attendance or breeding productivity. However, as found by a previous study of Great Skuas using a different (body) harness design, there was strong evidence of reduced overwinter return rates. Consequently, a device attached using a wing harness was considered suitable for long‐term deployment on Lesser Black‐backed Gulls, but not on Great Skuas. These findings will inform the planning of future tracking studies.     

Staurosporine-induced versus spontaneous squamous metaplasia in pre- and postmenopausal breast tissue

Breast cancers from pre- vs. postmenopausal women display unique characteristics that may be related to differences in epithelial differentiation between these two populations. In addition to lobular development, lactational changes, and involution, breast epithelium can undergo metaplastic alterations, often in association with carcinoma. Because protein kinase C (PKC) regulates differentiation and proliferation in many cell types, we asked whether modulation of PKC activity could define biochemical differences in breast epithelium from pre- vs. postmenopausal women. Organ cultures of normal human breast were treated with PKC agonists and antagonists. Epithelial differentiation was evaluated based on morphologic criteria and the expression of cell-type specific proteins. Staurosporine, a nonspecific but extremely potent inhibitor of PKC, induced squamous metaplasia in eight of eight cases within 2 weeks of treatment. Other inhibitors of PKC, such as calphostin C and tamoxifen, had no effect on epithelial differentiation. Long-term treatment with phorbol esters also did not induce squamous metaplasia. However, stimulation of cAMP levels by forskolin and isobutyl-methyl-xanthene (IMX) rapidly induced squamous metaplasia, as has been previously reported. Surprisingly, squamous metaplasia occurred in 10 of 12 cultures derived from postmenopausal women in the absence of exogenous agents. Untreated cultures derived from premenopausal women never developed this type of epithelium (0 of 11). Therefore, breast epithelium from pre- and postmenopausal women responded differently to in vitro culture. Forskolin/IMX or staurosporine can reproduce these conditions, acting independent of menopausal status. Because staurosporine's action was unique among PKC inhibitors, staurosporine may induce squamous metaplasia of breast epithelium by a PKC-independent mechanism. J. Cell. Physiol. 176:245–254, 1998. © 1998 Wiley-Liss, Inc.