Role of Tyrosine Phosphorylation in Ligand-induced Regulation of Transcytosis of the Polymeric Ig Receptor

The polymeric Ig receptor (pIgR) transcytoses its ligand, dimeric IgA (dIgA), from the basolateral to the apical surface of epithelial cells. Although the pIgR is constitutively transcytosed in the absence of ligand, binding of dIgA stimulates transcytosis of the pIgR. We recently reported that dIgA binding to the pIgR induces translocation of protein kinase C, production of inositol triphosphate, and elevation of intracellular free calcium. We now report that dIgA binding causes rapid, transient tyrosine phosphorylation of several proteins, including phosphatidyl inositol-specific phospholipase C-γl. Protein tyrosine kinase inhibitors or deletion of the last 30 amino acids of pIgR cytoplasmic tail prevents IgA-stimulated protein tyrosine kinase activation, tyrosine phosphorylation of phospholipase C-γl, production of inositol triphosphate, and the stimulation of transcytosis by dIgA. Analysis of pIgR deletion mutants reveals that the same discrete portion of the cytoplasmic domain, residues 727–736 (but not the Tyr734), controls both the ability of pIgR to cause dIgA-induced tyrosine phosphorylation of the phospholipase C-γl and to undergo dIgA-stimulated transcytosis. In addition, dIgA transcytosis can be strongly stimulated by mimicking phospholipase C-γl activation. In combination with our previous results, we conclude that the protein tyrosine kinase(s) and phospholipase C-γl that are activated upon dIgA binding to the pIgR control dIgA-stimulated pIgR transcytosis.

A comparative study of packing, transportation, and refrigeration costs of bushel baskets and wirebound boxes for transportation of peaches,

Mode of access: Internet.

Price programs of the United States Department of Agriculture, 1949 /

Includes index.

Plastic sealing of tobacco-storage warehouses /

"Issued June 1949."

The 1952 cotton goal : 16 million bales from 28 million acres.

"February 1952."

Integrated Carbon Budget Models for the Everglades Terrestrial-Coastal-Oceanic Gradient: Current Status and Needs for Inter-Site Comparisons

Recent studies suggest that coastal ecosystems can bury significantly more C than tropical forests, indicating that continued coastal development and exposure to sea level rise and storms will have global biogeochemical consequences. The Florida Coastal Everglades Long Term Ecological Research (FCE LTER) site provides an excellent subtropical system for examining carbon (C) balance because of its exposure to historical changes in freshwater distribution and sea level rise and its history of significant long-term carbon-cycling studies. FCE LTER scientists used net ecosystem C balance and net ecosystem exchange data to estimate C budgets for riverine mangrove, freshwater marsh, and seagrass meadows, providing insights into the magnitude of C accumulation and lateral aquatic C transport. Rates of net C production in the riverine mangrove forest exceeded those reported for many tropical systems, including terrestrial forests, but there are considerable uncertainties around those estimates due to the high potential for gain and loss of C through aquatic fluxes. C production was approximately balanced between gain and loss in Everglades marshes; however, the contribution of periphyton increases uncertainty in these estimates. Moreover, while the approaches used for these initial estimates were informative, a resolved approach for addressing areas of uncertainty is critically needed for coastal wetland ecosystems. Once resolved, these C balance estimates, in conjunction with an understanding of drivers and key ecosystem feedbacks, can inform cross-system studies of ecosystem response to long-term changes in climate, hydrologic management, and other land use along coastlines.

Soft tissue sarcoma: biology and therapeutic correlates

Soft tissue sarcomas (STS) comprise a heterogenenous group of greater than 50 malignancies of putative mesenchymal cell origin and as such they may arise in diverse tissue types in various anatomical locations throughout the whole body. Collectively they account for approximately 1% of all human malignancies yet have a spectrum of aggressive behaviours amongst their subtypes. They thus pose a particular challenge to manage and remain an under investigated group of cancers with no generally applicable new therapies in the past 40 years and an overall 5-year survival rate that remains stagnant at around 50%. From September 2000 to July 2006 I undertook a full time post-doctoral level research fellowship at the MD Anderson Cancer Center, Houston, Texas, USA in the department of Surgical Oncology to investigate the biology of soft tissue sarcoma and test novel anti- sarcoma adenovirus-based therapy in the preclinical nude rat model of isolated limb perfusion against human sarcoma xenografts. This work, in collaboration with colleagues as indicated herein, led to a number of publications in the scientific literature furthering our understanding of the malignant phenotype of sarcoma and reported preclinical studies with wild-type p53, in a replication deficient adenovirus vector, and oncolytic adenoviruses administered by isolated limb perfusion. Additional collaborative and pioneering preclinical studies reported the molecular imaging of sarcoma response to systemically delivered therapeutic phage RGD-4c AAVP. Doxorubicin chemotherapy is the single most active broadly applicable anti-sarcoma chemotherapeutic yet only has an approximate 30% overall response rate with additional breakthrough tumour progression and recurrence after initial chemo-responsiveness further problematic features in STS management. Doxorubicin is a substrate for the multi- drug resistance (mdr) gene product p-glycoprotein drug efflux pump and exerts its main mode of action by induction of DNA double-strand breaks during the S-phase of the cell cycle. Two papers in my thesis characterise different aspects of chemoresistance in sarcoma. The first shows that wild-type p53 suppresses Protein Kinase Calpha (PKCα) phosphorylation (and activation) of p-glycoprotein by transcriptional repression of PKCα through a Sp-1 transcription factor binding site in its -244/-234 promoter region. The second paper demonstrates that Rad51 (a central mediator of homologous recombination repair of double strand breaks) has elevated levels in sarcoma and particularly in the S- G2 phase of the cell cycle. Suppression of Rad51 with small interfering RNA in sarcoma cell culture led to doxorubicin chemosensitisation. Reintroduction of wild-type p53 into STS cell lines resulted in decreased Rad51 protein and mRNA expression via transcriptional repression of the Rad51 promoter through increased AP-2 binding. In light of poor response rates to chemotherapy, escape from local control portends a poor prognosis for patients with sarcoma. Two papers in my thesis characterise aspects of sarcoma angiogenesis, invasion and metastasis. Human sarcoma samples were found to have high levels of matrix metalloproteinase-9 (MMP-9) with expression levels that correlated with p53 mutational status. MMP-9 is known to degrade extracellular collagen, contribute to the control of the angiogenic switch necessary in primary tumour progression and facilitate invasion and metastasis. Reconstitution of wild-type p53 function led to decreased levels of MMP-9 protein and mRNA as well as zymography-assessed MMP-9 proteolytic activity and decreased tumour cell invasiveness. Reintroduction of wild-type p53 into human sarcoma xenografts in-vivo decreased tumour growth and MMP-9 protein expression. Wild-type p53 was found to suppress mmp-9 transcription via decreased binding of NF-κB to its -607/-595 mmp-9 promoter element. Studies on the role of the VEGF165 in sarcoma found that sarcoma cells stably transfected with VEGF165 formed more aggressive xenografted tumours with increased vascularity, growth rate, metastasis, and resistance to chemotherapy. Use of the anti-VEGFR2 antibody DC101 enhanced doxorubicin sensitivity at sub-conventional dosing, inhibited tumour growth, decreased development of metastases, and reduced tumour micro-vessel density while increasing the vessel maturation index. These effects were explained primarily through effects on endothelial cells (e.c.s), rather than the tumour cells per se, where DC101 induced e.c. sensitivity to doxorubicin and suppressed e.c. production of MMPs. The p53 tumour suppressor pathway is the most frequently mutated pathway in sarcoma. Recapitulation of wild-type p53 function in sarcoma exerts a number of anti-cancer outcomes such as growth arrest, resensitisation to chemotherapy, suppression of invasion, and attenuation of angiogenesis. Using a modified nude rat-human sarcoma xenograft model for isolated limb perfusion (ILP) delivery of wild-type p53 in a replication deficient adenovirus vector I showed that functionally competent wild-type p53 could be delivered to and detected in human leiomyosarcoma xenografts confirming preclinical feasibility - although not efficacious due to low transgene expression. Viral fibre modification to express the RGD tripeptide motif led to greater viral uptake by sarcoma cells in vitro (transductional targeting) and changing the transgene promoter to a response element active in cells with active telomerase expression restricted the transgene expression to the tumour intracellular environment (transcriptional targeting). Delivery of the fibre-modified, selectively replication proficient oncolytic adenovirus Ad.hTC.GFP/ E1a.RGD by ILP demonstrated a more robust, and tumour-restricted, transgene expression with evidence of anti-sarcoma effect confirmed microscopically. Collaborative studies using the fibre modified phage RGD-4C AAVP confirmed that systemic delivery specifically, efficiently, and repeatedly targets human sarcoma xenografts, binds to αv integrins in tumours, and demonstrates a durable, though heterogeneous, transgene expression of 1-4 weeks. Incorporation of the Herpes Simplex Virus thymidine kinase (HSVtk) transgene into RGD-4C AAVP permitted CT-PET spatial and temporal molecular imaging in vivo of transgene expression and allowed quantification of tumour metabolic activity both before and after interval administration of a systemic cytotoxic with predictable and measurable response to treatment before becoming apparent clinically. These papers further the medical and scientific community’s understanding of the biology of soft tissue sarcoma and report preclinical studies with novel and promising anti- sarcoma therapeutics.

Intranasal immunization with C. muridarum major outer membrane protein (MOMP) and cholera toxin elicits local production of neutralising IgA in the prostate

Successful control of sexually transmitted diseases (STDs) through vaccination will require the development of vaccine strategies that target protective immunity to both the female and male reproductive tracts (MRT). In the male, the immune privileged nature of the male reproductive tract provides a barrier to entry of serum immunoglobulins into the male reproductive ducts, thereby preventing the induction of protective immunity using conventional injectable vaccination techniques. In this study we investigated the potential of intranasal (IN) immunization to elicit anti-chlamydial immunity in BALB/c male mice. Intranasal immunization with Chlamydia muridarum major outer membrane protein (MOMP) admixed with cholera toxin (CT) resulted in high levels of MOMP-specific IgA in prostatic fluids (PF) and MOMP-specific IgA-secreting cells in the prostate. Prostatic fluid IgA inhibited in vitro infection of McCoy cells with C. muridarum. Using RT-PCR we also show that mRNA for the polymeric immunoglobulin receptor (PIgR), which transports IgA across mucosal epithelia, is expressed only in the prostate but not in other regions of the male reproductive ducts upstream of the prostate. These data suggest that using intranasal immunization to target IgA to the prostate may protect males against STDs while at the same time maintaining the state of immune privilege within the MRT.

Campylobacter jejuni and C. coli in Finnish poultry production

Campylobacter, mainly Campylobacter jejuni and C. coli, are worldwide recognized as a major cause of bacterial food-borne gastroenteritis. Epidemiological studies have shown handling or eating of poultry to be significant risk factors for human infections. Campylobacter contamination can occur at all stages of a poultry meat production cycle. The aim of this thesis was to study the occurrence and diversity of Campylobacter in broiler and turkey production in Finland. In summer 1999, 2.9 % of slaughtered broiler flocks were Campylobacter-positive. From the isolated strains 94 % were C. jejuni and 6% were C. coli. During years 2005-2006 one turkey parent flock, the hatchery, six different commercial turkey farms and different stages of the slaughterhouse were monitored during one and the half year. No Campylobacter were detected in either of the samples from the turkey parent flock or from the hatchery using the culture method. Instead PCR detected DNA of Campylobacter from the turkey parent flock and samples from the hatchery. Six out of 12 commercial turkey flocks were found negative at the farm level but only two of those were negative at slaughter. Campylobacter-positive samples within the flock at slaughter were detected between 0% and 94% with evisceration and chilling water being the most critical stages for contamination. All of Campylobacter isolates were shown to be C. jejuni. Campylobacter-positive turkey flocks were colonized by a limited number of Campylobacter genotypes both at the farm and slaughter level. In conclusion, in our first study in 1999 a low prevalence of Campylobacter in Finnish broiler flocks was detected and it has remained at a low level during the study period until the present. In the turkey meat production, we found that flocks which were negative at the farm became contaminated with Campylobacter at the slaughter process. These results suggest that proper and efficient cleaning and disinfection of slaughter and processing premises are needed to avoid cross-contamination. Prevention of colonization at the farm by a high level of biosecurity control and hygiene may be one of the most efficient ways to reduce the amount of Campylobacter-positive poultry meat in Finland. With a persistent low level of Campylobacter-positive flocks, it could be speculated that the use of logistic slaughtering, according to Campylobacter status at farm, might have be advantageous in reducing Campylobacter contamination of retail poultry products. However, the significance of the domestic poultry meat for human campylobacteriosis in Finland should be evaluated.

Campylobacter jejuni and C.coli in Finnish poultry production

Campylobacter, mainly Campylobacter jejuni and C. coli, are worldwide recognized as a major cause of bacterial food-borne gastroenteritis (World Health Organization 2010). Epidemiological studies have shown handling or eating of poultry to be significant risk factors for human infections. Campylobacter contamination can occur at all stages of a poultry meat production cycle. In summer 1999, every broiler flock from all three major Finnish poultry slaughterhouses was studied during a five month period. Caecal samples were taken in the slaughterhouses from five birds per flock. A total of 1 132 broiler flocks were tested and 33 (2.9%) of those were Campylobacter-positive. Thirty-one isolates were identified as C. jejuni and two isolates were C. coli. The isolates were serotyped for heat-stable antigens (HS) and genotyped by pulsed-field gel electrophoresis (PFGE). The most common serotypes found were HS 6,7, 12 and 4-complex. Using a combination of SmaI and KpnI patterns, 18 different PFGE types were identified. Thirty-five Finnish C. jejuni strains with five SmaI/SacII PFGE types selected among human and chicken isolates from 1997 and 1998 were used for comparison of their PFGE patterns, amplified fragment length polymorphism (AFLP) patterns, HaeIII ribotypes, and HS serotypes. The discriminatory power of PFGE, AFLP and ribotyping with HaeIII were shown to be at the same level for this selected set of strains, and these methods assigned the strains into the same groups. The PFGE and AFLP patterns within a genotype were highly similar, indicating genetic relatedness. An HS serotype was distributed among different genotypes, and different serotypes were identified within one genotype. From one turkey parent flock, the hatchery, six different commercial turkey farms (together 12 flocks) and from 11 stages at the slaughterhouse a total of 456 samples were collected during one and the half year. For the detection of Campylobacter both conventional culture and a PCR method were used. No Campylobacter were detected in either of the samples from the turkey parent flock or from the hatchery samples using the culture method. Instead PCR detected DNA of Campylobacter in five faecal samples from the turkey parent flock and in one fluff and an eggshell sample. Six out of 12 commercial turkey flocks were found negative at the farm level but only two of those were negative at slaughter. Campylobacter-positive samples within the flock at slaughter were detected between 0% and 94%, with evisceration and chilling water being the most critical stages for contamination. All of a total of 121 Campylobacter isolates were shown to be C. jejuni using a multiplex PCR assay. PFGE analysis of all isolates with KpnI restriction enzyme resulted in 11 PFGE types (I-XI) and flaA-SVR typing yielded nine flaA-SVR alleles. Three Campylobacter-positive turkey flocks were colonized by a limited number of Campylobacter genotypes both at the farm and slaughter level.In conclusion, in our first study in 1999 a low prevalence of Campylobacter in Finnish broiler flocks was detected and it has remained at a low level during the study period until the present. In the turkey meat production, we found that flocks which were negative at the farm became contaminated with Campylobacter at the slaughter process. These results suggest that proper and efficient cleaning and disinfection of slaughter and processing premises are needed to avoid cross-contamination. Prevention of colonization at the farm by a high level of biosecurity control and hygiene may be one of the most efficient ways to reduce the amount of Campylobacter-positive poultry meat in Finland. In Finland, with a persistent low level of Campylobacter-positive flocks, it could be speculated that the use of logistic slaughtering, according to Campylobacter status at farm, might have be advantageous in reducing Campylobacter contamination of retail poultry products. However, the significance of the domestic poultry meat for human campylobacteriosis in Finland should be evaluated.

On methods of evaluation of bacterial production. [Translation from: Lietuvas TSR Mokslu Akademijos Darbai, C Serija 2(55) 3-9, 1971.]

By now a great deal of work is known concerning the methods of determining the production of bacteria or similar questions; among these the problems of a common terminology is discussed. The article discusses formulae of production of bacterial populations over time.

Application Of (CS)-C-137 fingerprinting technique to interpreting sediment production records from reservoir deposits in a small catchment of the Hilly Loess Plateau；China

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