bluuebunny/crossref_metadata_2025 huggingface dataset:
Pancreatic response of rats fed genetically modified soybean
Authors: Magaña‐Gómez Javier A. , Cervantes Guillermo López , Yepiz‐Plascencia Gloria , Barca Ana M. Calderón de la
Published: November 2007

Mice fed genetically modified (GM) soybean were not affected in nutritional performance, but pancreatic microscopic features were disturbed. The mechanisms for these contradictory findings are unknown. This study analysed the histology of acinar pancreatic cells and the expression of pancreatitis‐associated protein (PAP) and trypsinogen mRNA in rats fed GM soy protein. Two bioassays were run, each one with 34 Wistar rats distributed into two groups fed with non‐GM or GM‐soy protein (18% protein) for 0, 1, 3, 5, 15 and 30 days. Nutritional evaluation, plasma amylase levels, pancreatic histological analysis and quantification of PAP and trypsinogen mRNAs levels using quantitative real‐time RT‐PCR were done. No differences in nutritional performance among rats fed non‐GM and GM diets were found. The GM, but not the non‐GM, diet induced zymogen‐granule depletion after 15 days feeding, returning to normal levels after 30 days (P < 0.05). Acinar disorganization started as early as 5 days after initiation of the GM diet and it recovered after 30 days. Levels of PAP mRNA significantly increased in the GM diet between day 1 and day 3 and decreased to the basal level by day 15. Trypsinogen mRNA peaked at two different times; at day 1 and at day 15, decreasing to basal levels after 30 days. Plasma amylase levels remained unchanged at all times. This indicates that GM soy protein intake affected pancreas function, evidenced by the early acute PAP mRNA increased levels and pancreas cellular changes followed by recuperation of acinar cells after 30 days. Copyright © 2007 John Wiley & Sons, Ltd.
Biocompatibility and gelation of chitosan–glycerol phosphate hydrogels
Authors: Ahmadi Raheleh , de Bruijn Joost D.
Published: November 2007

The aim of this study was to evaluate the cytotoxicity and gelation of thermosensitive chitosan‐β‐glycerol phosphate (GP) solutions, which undergo sol–gel transition around body temperature. Chitosan 0.5–2% (w/v) mixed with GP 5–20% (w/v) solutions all gel at 37°C and possess pH around the physiological range. High GP and chitosan concentrations result in faster gelation time. Extracts of all chitosan concentrations mixed with or without 5% (w/v) GP and 2% (w/v) chitosan combined with 10% (w/v) GP demonstrated up to 34% increase in proliferation rate of goat bone marrow derived mesenchymal stem cells when compared with control medium. Extracts from all other chitosan‐GP combinations resulted in reduced cell proliferation relative to control medium. Increasing GP content in the gel resulted in a linear increase in the osmolality of the extracts in contact with the gels. The results of this study indicate that chitosan‐GP is a biocompatible hydrogel, extracts of which can stimulate mesenchymal stem cell proliferation at certain concentrations. This material is therefore a promising vehicle for cell encapsulation and injectable tissue‐engineering applications. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res 2008
Overexpression of Par‐4 enhances thapsigargin‐induced apoptosis via down‐regulation of XIAP and inactivation of Akt in human renal cancer cells
Authors: Lee Tae‐Jin , Lee Jung‐Tae , Kim Sang Hyun , Choi Yung Hyun , Song Kyoung Seob , Park Jong‐Wook , Kwon Taeg Kyu
Published: November 2007

The prostate‐apoptosis‐response‐gene‐4 (Par‐4) protein has been shown to function as an effector of cell death in response to various apoptotic stimuli that trigger mitochondria and membrane receptor‐mediated cell death pathways. We found that overexpressing Par‐4 by stable transfection sensitizes Caki cells to induction of apoptosis by TRAIL and drugs that induce endoplasmic reticulum (ER) stress [thapsigargin (TG), tunicamycin (TU) and etoposide]. Ectopic expression of Par‐4 is associated with decreased levels of XIAP protein in TG‐treated cells, caused in part by XIAP protein instability and caspase activation. Levels of phospho‐Akt are decreased in Caki/Par‐4 cells to a significantly greater extent than in Caki/Vector cells by treatment with TG, and this is in turn associated with decreased levels of phospho‐PDK1, the kinase upstream of Akt. In conclusion, we provide evidence that ectopic expression of Par‐4 sensitizes Caki cells to TG and that XIAP protein instability and inactivation of Akt are important in cellular pathways affected by Par‐4. J. Cell. Biochem. 103: 358–368, 2008. © 2007 Wiley‐Liss, Inc.
Simultaneous detection of protozoa in the tissues of snakes by double in situ hybridization
Authors: Richter Barbara , Fragner Karin , Weissenböck Herbert
Published: November 2007

Different methods have been established for the simultaneous detection of different pathogens in tissue samples, each with certain advantages and disadvantages. Chromogenic in situ hybridization combines specific molecular pathogen detection with microscopic evaluation of pathogen quantity, morphology and distribution, as well as associated tissue damage. Furthermore, only a minimum of usually costly technical equipment is needed. The aim of our study was to detect two different protozoa simultaneously in tissue samples using exclusively digoxigenin (DIG)‐labeled probes and alkaline phosphatase‐coupled anti‐DIG‐antibodies and the chromogens Vector Red and NBT/BCIP with standard protocols. Gastrointestinal tissue samples from 15 snakes infected with either one or two protozoan species were investigated. All expected protozoa stained clearly dark purple or bright red, respectively, depending on the chromogen used. This technique can be used in pathogenicity studies of various pathogens in any kind of tissue. Microsc. Res. Tech., 2008. © 2007 Wiley‐Liss, Inc.
Mitochondrial nuclear receptors and transcription factors: Who's minding the cell?
Authors: Lee Junghee , Sharma Swati , Kim Jinho , Ferrante Robert J. , Ryu Hoon
Published: November 2007

Mitochondria are power organelles generating biochemical energy, ATP, in the cell. Mitochondria play a variety of roles, including integrating extracellular signals and executing critical intracellular events, such as neuronal cell survival and death. Increasing evidence suggests that a cross‐talk mechanism between mitochondria and the nucleus is closely related to neuronal function and activity. Nuclear receptors (estrogen receptors, thyroid (T3) hormone receptor, peroxisome proliferators‐activated receptor gamma2) and transcription factors (cAMP response binding protein, p53) have been found to target mitochondria and exert prosurvival and prodeath pathways. In this context, the regulation of mitochondrial function via the translocation of nuclear receptors and transcription factors may underlie some of the mechanisms involved in neuronal survival and death. Understanding the function of nuclear receptors and transcription factors in the mitochondria may provide important pharmacological utility in the treatment of neurodegenerative conditions. Thus, the modulation of signaling pathways via mitochondria‐targeting nuclear receptors and transcription factors is rapidly emerging as a novel therapeutic target. © 2007 Wiley‐Liss, Inc.
α‐Amino‐3‐hydroxy‐5‐methyl‐4‐isoxazole propionate attenuates glutamate‐induced caspase‐3 cleavage via regulation of glycogen synthase kinase 3β
Authors: Nishimoto Takaaki , Kihara Takeshi , Akaike Akinori , Niidome Tetsuhiro , Sugimoto Hachiro
Published: November 2007

Preconditioning of sublethal ischemia exhibits neuroprotection against subsequent ischemia‐induced neuronal death. It has been indicated that glutamate, an excitatory amino acid, is involved in the pathogenesis of ischemia‐induced neuronal death or neurodegeneration. To elucidate whether prestimulation of glutamate receptor could counter ischemia‐induced neuronal death or neurodegeneration, we examined the effect of α‐amino‐3‐hydroxy‐5‐methyl‐4‐isoxazole propionate (AMPA), an ionotropic subtype of glutamate receptor, on excess glutamate‐induced excitotoxicity using primary cortical neuronal cultures. We found that AMPA exerted a neuroprotective effect in a time‐ and concentration‐dependent manner. A blocker of phosphatidylinositol‐3 kinase (PI3K), LY294002 (10 μM), significantly attenuated AMPA‐induced protection. In addition, Ser473 of Akt/PKB, a downstream target of PI3K, was phosphorylated by AMPA administration (10 μM). Glycogen synthase kinase 3β (GSK3β), which has been reported to be inactivated by Akt, was phosphorylated at Ser9 by AMPA. Ser9‐phosphorylated GSK3β or inactivated form would be a key molecule for neuroprotection, insofar as lithium chloride (100 μM) and SB216763 (10 μM), inhibitors of GSK3β, also induced phosphorylation of GSK3β at Ser9 and exerted neuroprotection, respectively. Glutamate (100 μM) increased cleaved caspase‐3, an apoptosis‐related cysteine protease, and caspase‐3 inhibitor (Ac‐DEVD‐CHO; 1 μM) blocked glutamate‐induced excitotoxicity in our culture. AMPA (10 μM, 24 hr) and SB216763 (10 μM) prominently decreased glutamate‐induced caspase‐3 cleavage. These findings suggest that AMPA activates PI3K‐Akt and subsequently inhibits GSK3β and that inactivated GSK3β attenuates glutamate‐induced caspase‐3 cleavage and neurotoxicity. © 2007 Wiley‐Liss, Inc.
Glial ensheathment of peripheral axons in Drosophila
Authors: Banerjee Swati , Bhat Manzoor A.
Published: November 2007

The ensheathment of neurons and their axons creates an ion‐sensitive microenvironment that allows rapid conduction of nerve impulses. One of the fundamental questions about axonal ensheathment is how insulating glial cells wrap around axons. The mechanisms that underlie insulation of axons in invertebrates and vertebrates are not fully understood. In the present article we address cellular aspects of axonal ensheathment in Drosophila by taking advantage of glial mutants that illustrate a range of phenotypic defects including ensheathment of axons. From the findings of these mutant studies, we summarize that loss of glial cells, defects in glial membrane wrapping, failure of glial migration, and loss of specialized ladderlike septate junctions between ensheathing glial membranes result in axon‐glial functional defects. These studies provide a broad perspective on glial ensheathment of axons in Drosophila and key insights into the anatomical and cellular aspects of axonal insulation. Given the powerful genetic approaches available in Drosophila, the axonal ensheathment process can be dissected in great detail to reveal the fundamental principles of ensheathment. These observations will be relevant to understanding the very similar processes in vertebrates, where defects in glial cell functions lead to devastating neurological diseases. © 2007 Wiley‐Liss, Inc.
Spontaneous pneumothorax in children: When is invasive treatment indicated?
Authors: O'Lone E. , Elphick H.E. , Robinson P.J.
Published: November 2007

A retrospective review of pneumothoraces in children presenting to a major tertiary children's hospital is described. A total of 35 cases in 31 patients of spontaneous pneumothorax were identified over a 10‐year period. There was one case of bilateral pneumothorax and three cases of recurrent pneumothoraces. Twenty‐four cases (69%) required intercostal tube catheter drainage for a mean of 4.9 days (range 2–10 days). Eleven cases, including two cases in CF patients, and three cases in patients with Marfan's Syndrome proceeded to a secondary surgical procedure after a continuing air leak was present for an average of 5.9 days (range 2–16 days). In follow‐up studies on 11 cases, 5 (45%) were found to have apical abnormalities of the lung on CT scanning. Pneumothoraces were identified in six cases of patients with cystic fibrosis as well as four in patients with Marfan's Syndrome. This present study has suggested that unless intercostal catheter treatment resolves the air leak associated with a spontaneous pneumothorax within 5 days that surgical intervention is most likely to be required to achieve a full resolution. Pediatr Pulmonol. 2008; 43:41–46. © 2007 Wiley‐Liss, Inc.
Psychiatric diagnosis and aggression before acute hospitalisation
Authors: Colasanti A. , Natoli A. , Moliterno D. , Rossattini M. , De Gaspari I.F. , Mauri M.C.
Published: November 2007

Objective

To examine the predictors of aggressive behaviours occurring before acute hospitalisation.

Methods

We analysed 350 acute admissions to a psychiatric ward during a 12-month period. The diagnoses were formulated according to the DSM IV axis I and II criteria. Aggressive behaviours occurring in the week before admission were retrospectively assessed using the modified overt aggression scale. The patients' clinical and sociodemographic variables, concurrent drug or alcohol abuse, and admission status were recorded at the time of admission.

Results

Aggressive and violent behaviours were highly prevalent, respectively, in 45% and 33% of the cases. Violence before admission was independently associated with drug abuse, involuntary admission status, and severe psychopathology. A diagnosis of a psychotic disorder did not increase the risk of aggression or violence, compared to the other psychiatric diagnoses. Personality disorders were significantly more associated to aggressive behaviours than psychotic disorders.

Conclusion

The diagnosis of psychotic disorder is a poor predictor of aggression in a sample of psychiatric patients. Other clinical and non-clinical variables are associated to aggression before hospitalisation: they include drug abuse, involuntary admission status, general severity of symptoms, and diagnosis of personality disorder.
Regulation of the epithelial calcium channel TRPV6 by the serum and glucocorticoid‐inducible kinase isoforms SGK1 and SGK3
Authors: Böhmer C. , Palmada M. , Kenngott C. , Lindner R. , Klaus F. , Laufer J. , Lang F.
Published: November 2007

Epithelial calcium (re)absorption is mediated by TRPV5 and TRPV6 channels. TRPV5 is modulated by the SGK1 kinase, a process requiring the PDZ‐domain containing scaffold protein NHERF2. The present study explored whether TRPV6 is similarly regulated by SGKs and the scaffold proteins NHERF1/2. In Xenopus oocytes, SGKs activate TRPV6 by increasing its plasma membrane abundance. Deletion of the putative PDZ binding motif on TRPV6 did not abolish channel activation by SGKs. Furthermore, coexpression of neither NHERF1 nor NHERF2 affected TRPV6 or potentiated the SGKs stimulating effect. The present observations disclose a novel TRPV6 regulatory mechanism which presumably participates in calcium homeostasis.
Metacaspase 2 of Trypanosoma brucei is a calcium‐dependent cysteine peptidase active without processing
Authors: Moss Catherine X. , Westrop Gareth D. , Juliano Luiz , Coombs Graham H. , Mottram Jeremy C.
Published: November 2007

Metacaspases are cysteine peptidases that are distantly related to the caspases, for which proteolytic processing is central to their activation. Here, we show that recombinant metacaspase 2 (MCA2) from Trypanosoma brucei has arginine/lysine‐specific, Ca2+‐dependent proteolytic activity. Autocatalytic processing of MCA2 occurred after Lys55 and Lys268; however, this was shown not to be required for the enzyme to be proteolytically active. The necessity of Ca2+, but not processing, for MCA2 enzymatic activity clearly distinguishes MCA2 from the caspases and would be consistent with different physiological roles.
Systematic review of factors contributing to penicillin treatment failure in Streptococcus pyogenes pharyngitis
Authors: Pichichero Michael E. , Casey Janet R.
Published: November 2007

Objective

Review the evidence for various explanations for microbiologic treatment failure following use of penicillin in group A streptococcal (GAS) tonsillopharyngitis.

DATA SOURCE

Systematic review of the literature based on Medline and EMBASE searches, and review of reference lists of included studies.

RESULTS

The explanations for penicillin treatment failure in GAS tonsillopharyngitis include 1) carrier state, 2) lack of compliance, 3) recurrent exposure, 4) in vivo copathogenicity of β‐lactamase–producing normal pharyngeal flora, 5) in vivo bacterial coaggregation, 6) poor antibiotic penetration to tonsillopharyngeal tissue, 7) in vivo eradication of normal protective flora, 8) early initiation of antibiotic therapy resulting in suppression of an adequate host immune response, 9) intracellular localization of GAS, 10) GAS tolerance to penicillin, 11) contaminated toothbrushes or orthodontic appliances, and 12) transmission from the family pet. There is very little type I or II evidence to support any of the above‐cited explanations for treatment failure in GAS tonsillopharyngitis; available studies are mostly observational (in patients) or laboratory‐based without clinical confirmation.

CONCLUSION

Multiple explanations have been offered by investigators to explain penicillin treatment failures in GAS tonsillopharyngitis, but the evidence base to support the proposed explanations is generally weak by current standards. Further research is needed to better understand the mechanism(s) of penicillin treatment failure in GAS tonsillopharyngitis.
Prevalence and ethnicity of sleep‐disordered breathing and obesity in children
Authors: Rudnick Emily F. , Walsh Jonathan S. , Hampton Mark C. , Mitchell Ron B.
Published: November 2007

OBJECTIVES

To compare the prevalence of obesity in children with sleep‐disordered breathing (SDB) who undergo adeno‐tonsillectomy to that in the general pediatric population. DESIGN: Cross‐sectional controlled study.

METHODS

A body‐mass‐index (BMI‐for‐age) percentile was determined for children with SDB and for matched controls from a general pediatric clinic. Children who were obese (<85th %) were analyzed. Groups were compared using a t test or χ2 analysis. Risk factors were estimated with logistic regression.

RESULTS

The study population included 299 children, of whom 170 (56.9%) had SDB. Compared with controls, more children with SDB were obese (46% vs 33%, P = 0.029) or underweight (8% vs 3%, P = 0.110), and fewer children with SDB were healthy weight (46% vs 64%, P = 0.002). Among African American children, those who were obese were more likely to have SDB (OR, 2.22, P < 0.01).

CONCLUSIONS

Children with SDB who undergo adenoton‐sillectomy are more likely to be obese than children seen in a general pediatric clinic. African American children who are obese are more likely to have SDB.
Extending the traditional resection limits of squamous cell carcinoma of the anterior skull base
Authors: Ducic Yadranko , Miles Brett A. , Sabatini Peter
Published: November 2007

Objective

Preliminary report to evaluate the efficacy of resection of squamous cell carcinomas that demonstrate intracra‐nial invasion.

Methods

A retrospective review of all cases of extracranial squamous cell carcinomas that extend intracranially treated by a single surgeon.

Results

A total of 21 cases were reviewed. In 6 cases, there was noted to be overt brain invasion. Complete resection of the intracranial disease was achieved in each of the remaining 15 cases. There were no instances of CSF leak, meningitis, brain abscess, stroke, or other intracranial complication noted either acutely or secondarily. In follow‐ups that ranged from 10 months (single patient died of disease at 10 months) to 6 years (average, 3.8 years), there were no instances of intracranial recurrence. There was a disease‐free control rate of 67.7% at an average follow‐up of 4.1 years.

Conclusions

Extending the resection of squamous cell carcinoma into the intracranial vault judiciously as outlined appears to be associated with acceptable outcomes in the treatment of advanced squamous cell carcinoma of the skull base.
Management outcomes following lateral temporal bone resection for ear and temporal bone malignancies
Authors: Moore Michael G. , Deschler Daniel G. , McKenna Michael J. , Varvares Mark A. , Lin Derrick T.
Published: November 2007

Objective

To evaluate clinical outcomes following lateral temporal bone resection (LTBR) for management of malignancies involving the ear or temporal bone.

Subjects and Methods

A retrospective medical record review was performed on patients receiving LTBR for management of malignancies involving the ear or temporal bone between 1990 and 2007.

Results

In this group of 35 patients, the mean age was 62.7 years, with tumor histopathologies including squamous cell carcinoma (SCC, 20), basal cell carcinoma (BCC, 7), adenoid cystic carcinoma (ACC, 7), and adenocarcinoma (1). The 5‐year overall survival (OS), disease‐specific survival (DSS), and disease‐free survival (DFS) were 77%, 79%, and 52%, respectively. Complete resection resulted in improved OS, DSS, and DFS (P < 0.004 for each) and reduced local recurrence (P < 0.001).

Conclusions

In patients with carcinomas of the ear and temporal bone, upfront excision including LTBR is an effective management when combined with postoperative radiation therapy. Complete removal of all disease may improve survival and decrease recurrence.
The day‐of‐the‐week effect and conditional volatility: Sensitivity of error distributional assumptions
Authors: Baker H. Kent , Rahman Abdul , Saadi Samir
Published: November 2007

We test for reliable evidence of the day‐of‐the‐week effect on both the mean and volatility for the S&P/TSX Canadian return index. Unlike previous studies, we permit several specifications for the error distribution — GARCH normal, Student's t, generalized error distribution, and double exponential distribution. Unlike other studies, we find that the day‐of‐the‐week effect in both mean and conditional volatility is sensitive to the particular specification of the underlying distributions. We also find that using a regression analysis assuming a Student's t distribution is a better way to investigate this effect. Our evidence demonstrates the apparent fragility of previous empirical studies on calendar anomalies. Thus, our results serve as a warning that with financial data, the error distributional assumptions are critical to correctly identifying empirical regularities in the data.
Changing trends in bacteriology of peritonsillar abscess
Authors: Megalamani S B , Suria G , Manickam U , Balasubramanian D , Jothimahalingam S
Published: November 2007

Objectives:

To evaluate the type of aerobic bacteria commonly isolated from peritonsillar abscesses.

Study design:

A retrospective study involving 60 patients presenting with peritonsillar abscess treated between 2003 and 2006.

Setting:

The patients were treated in a tertiary care, teaching hospital. The records of the patients were reviewed and analysed.

Results:

Gram-positive organisms were commonly isolated from the abscesses. However, an increasing trend towards Gram-negative bacterial isolates was noted. The antibiogram showed changing patterns of sensitivity, with a resistance to penicillin.

Conclusion:

There is an increasing incidence of Gram-negative aerobic bacteria causing peritonsillar abscess. Appropriate antibiotics for Gram-negative bacteria should be included in the regimen if such bacteria are isolated in culture and sensitivity studies.

Significance:

Empirical antibiotics with Gram-negative cover will be appropriate as adjunctive therapy.
Functional vocal results after CO2 laser endoscopic surgery for glottic tumours
Authors: Motta S , Cesari U , Mesolella M , Motta G
Published: November 2007

Introduction:

Vocal results after endoscopic cordectomy have not yet been well defined. The aim of this study was to assess the vocal function of patients who had undergone CO2 laser cordectomy.

Design:

Retrospective, observational and control group study, conducted in a tertiary care medical department.

Methods:

One hundred and thirty-five male patients (age range 36–83 years) underwent different types of endoscopic cordectomy. Forty age-matched, euphonic male subjects were selected as controls. Patients were classified according to the main site of the phonatory neo-glottis. Outcome measures were maximum phonation time, vocal intensity and harmonic/noise ratio. Mann–Whitney and rank Spearman tests were used for statistical analysis.

Results:

Findings indicated statistically significant differences for all parameters, comparing patients and controls (p<0.001), and a direct positive relation between type of functional compensation and outcome measures in the study patients (p<0.001).

Conclusions:

The results indicate that functional compensation and outcome measures were related, and that no functional compensation enabled the study patients to achieve a voice quality comparable with that of controls.
Defending polar empire: opposition to India's proposal to raise the ‘Antarctic Question’ at the United Nations in 1956
Authors: Howkins Adrian
Published: November 2007

This paper examines the international response to India's 1956 proposal to raise the ‘Antarctic Question’ at the United Nations. It focuses in particular on the uneasy alliance that developed between the British Commonwealth and Latin America in opposition to the Indian proposal. Although Great Britain, Argentina, and Chile were bitterly disputing the sovereignty of the Antarctic Peninsula region, they shared a common desire to keep the southern continent off the agenda of the United Nations. This ability to work together for common goals, despite their differences, set an important precedent for the Antarctic Treaty that would be signed in 1959. In this way, opposition to the Indian proposal, more than the proposal itself, played an important role in the history of Antarctica in the 1950s. Latin American opposition to the proposal helped to fragment any ‘anti-imperial’ coalition that might have developed in Antarctica. This fragmentation helps us to place the Antarctic Treaty System into the framework of post-colonial studies.
Human geographies of sea ice: freeze/thaw processes around Cape Dorset, Nunavut, Canada
Authors: Laidler Gita J. , Elee Pootoogoo
Published: November 2007

Sea ice has been, and continues to be, an integral component of life in the Inuit community of Cape Dorset, Nunavut. Located on an island of the same name off the southwestern coast of Baffin Island, the strong Hudson Strait currents prevent extensive ice formation around the community. Nevertheless, sea ice remains an important travel and hunting platform, enabling access to Baffin Island, hunting and fishing grounds, and nearby communities. With the combined importance, dynamism, and continuous use of this frozen ocean environment, local Inuit elders and hunters have developed a detailed and nuanced understanding of sea ice conditions, freeze/thaw processes, and the influences of winds and currents on ice conditions. Working collaboratively with the community of Cape Dorset since October, 2003, we present the results of 30 semi-directed interviews, 5 sea ice trips, and 2 focus groups to provide a baseline understanding of local freezing processes (near-shore, open water, sea ice thickening, landfast ice, floe edge, and tidal cracks), melting processes (snow melt, water accumulation and drainage, break-up, and cracks/leads), wind influences on sea ice (wind direction and strength affecting sea ice formation, and movement), and current influences on sea ice (tidal variations and current strength affecting sea ice formation, movement, and polynya size/location). Strong emphasis is placed on Inuktitut terminology and spatial delineations of localised ice conditions and features. Therefore, this paper provides insights into local scale ice conditions and dynamics around Cape Dorset that are not captured in regional scale studies of Hudson Bay and/or Hudson Strait. Results have the potential to inform future research efforts on local/regional sea ice monitoring, the relationship between Inuit knowledge, language, and the environment, and addressing community interests through targeted studies.
Discovery of heavy negative ions in Titan's ionosphere
Authors: Coates A. J. , Crary F. J. , Lewis G. R. , Young D. T. , Waite J. H. , Sittler E. C.
Published: November 2007

Titan's ionosphere contains a rich positive ion population including organic molecules. Here, using CAPS electron spectrometer data from sixteen Titan encounters, we reveal the existence of negative ions. These ions, with densities up to ∼100 cm−3, are in mass groups of 10–30, 30–50, 50–80, 80–110, 110–200 and 200+ amu/charge. During one low encounter, negative ions with mass per charge as high as 10,000 amu/q are seen. Due to their unexpectedly high densities at ∼950 km altitude, these negative ions must play a key role in the ion chemistry and they may be important in the formation of organic‐rich aerosols (tholins) eventually falling to the surface.
Mapping the GPS multipath environment using the signal‐to‐noise ratio (SNR)
Authors: Bilich Andria , Larson Kristine M.
Published: November 2007

GPS multipath, where a signal arrives by more than one path, is a source of positioning error which cannot be easily neutralized. Better understanding of the multipath environment, i.e., the direction of and distance to reflecting objects, is important for multipath mitigation during the site construction phase as well as discerning the impact of multipath on positioning estimates for existing sites. This paper presents a tool called power spectral mapping that visually represents the multipath environment of a GPS site. This technique uses the spectral content (frequency and magnitude) of signal‐to‐noise ratio (SNR) time series to determine which satellites, and therefore which portions of the antenna environment, contribute significant multipath error and at what frequencies. Wavelet analysis is used to extract the time‐varying frequency and magnitude content of various multipath constituents, and these data are projected onto a map representing the GPS antenna surroundings. Power spectral map examples from stations with very different multipath environments are presented. The maps are interpreted in terms of potential sources of multipath reflections, and how these multipath signals contribute to positioning error at each station is also assessed.
ISOELECTRIC FOCUSING IN POLYACRYLAMIDE GELS
Authors: Percival Lorraine H , Dunckley GG , Purves HD
Published: November 2007

An improved technique for isoelcctric focusing of proteins in polyacrylamide gels is described.

In studying insulin with the procedure, mercuric chloride in trichloro‐acetic acid was used to fix the protein in the gel.

One major and five minor components were demonstrated in ox and pig insulin.
THE GENETICS OF THE HL‐A SYSTEM IN A CAUCASIAN AUSTRALIAN POPULATION AND ITS RELATIONSHIP TO RENAL TRANSPLANTATION
Authors: Ting A , Morris PJ
Published: November 2007

The well defined antigens HL‐A1, ‐A2, ‐A3, ‐A5, ‐A7, ‐A8, ‐A9 and ‐A12 as well as the complex antigens 4a and 4b have been studied in 306 unrelated Individuals and 35 families all of Caucasian Australian extract.

The results are compatible with the concept that the HL‐A system is made up of two segregant series of antigens, each series being multiallelic and closely linked. However, the HL‐A antigens from the two series appear to show associations within two groups. As well, each group appears to be associated with the complex antigens 4a and 4b. An alternative hypothesis for the genetic control of the HL‐A antigens is proposed, suggesting that 4a and 4b are precursor substances from which the HL‐A antigens are produced by gene action in a manner analogous to the ABO system in man.

These findings imply that matching of unrelated individuals in organ transplantation will be difficult. However, if the hypothesis for the genetic control of HL‐A is valid then matching will be simplified, as it could be based on the precursor groups.
ROLE OF THE FACE IN THE CARDIOVASCULAR RESPONSES TO TOTAL IMMERSION
Authors: Cooden BA , Lehman RC , Pym J
Published: November 2007

Eleven of nineteen young adults development bradycardia and reduced forearm blood flow within 30 seconds of breath‐holding with total body immersion and were classified as strong responders. Analysis of data from these strong responders showed that, when the face was lifted from the water after 30 seconds’ total immersion, the development of the diving response ceased, and both heart rate and blood flow returned towards resting levels even though the breath was still held. Conversely, total immersion after 30 seconds of breath‐ holding with the face in air produced bradycardia of rapid onset and decreased blood flow. Wearing a face mask and swimming cap prevented the development of the usual diving response.
A METHOD FOR MEASURING THE NORMAL BLOOD VOLUME OF THE RAT USING [125I]LABELLED ALBUMIN
Authors: Brooks Sandra
Published: November 2007

A reliable method of estimating blood volume in the rat using [125I]labelled albumin is described. In 16 normal animals the blood volume was found to be 5·59 ml./100 g. body weight (± 0·44 ml. standard deviation). A standard error of ± 0·11 ml. in this technique is small and therefore should allow changes in blood volume due to pathological states to be accurately measured.
COBALT‐SELENIUM INTERACTIONS IN THE NUTRITION OF THE RAT
Authors: Gardiner MR , Nicol Helen
Published: November 2007

An interaction between dietary cobalt and selenium was revealed when groups of female weanling rats were fed standard rations, containing different concentrations and ratios of the two trace elements, continuously over a 15 week period. It was found that the levels of selenium in the heart and skeletal muscle were positively related to dietary selenium and negatively related to dietary cobalt, and that the levels of selenium in liver and kidney were positively related to dietary selenium and negatively related to an interaction between dietary selenium and cobalt. Dietary selenium did not influence the cobalt level of heart muscle. Bodyweight gains and histological appearance of the major tissues of rats fed either or both of the trace elements in concentrations as high as 8·6 p.p.m. in the ration were not affected except for some minor liver changes in those on the ration containing 8·6 p.p.m. cobalt and low levels of selenium. It was suggested that cobalt/selenium interactions probably occurred in the gut with effects on absorption rather than in the tissues studied.
COPPER DEFICIENCY IN THE RAT EFFECT ON SYNTHESIS OF PHOSPHOLIPIDS
Authors: Gallagher CH , Reeve Vivienne E
Published: November 2007

Copper deficiency depresses phospholipid synthesis by liver mitochondria, but not by liver microsomes. The effect of copper deficiency on mitochondrial phospholipid synthesis is eliminated by adding 1 mM ATP. Phospholipid synthesis by liver mitochondria from normal rats is inhibited by 0·1–1 mM CN− and restored to normal by 1mM ATP. Mitochondria do not synthesise phospholipids significantly under anaerobic conditions with or without added electron transfer systems unless ATP is added. There appears to be a direct causal relationship between the two major biochemical disturbances in copper deficiency. One, the loss of cytochrome oxidase activity, leading to the other, depressed synthesis of phospholipids by liver mitochondria, by interfering with the provision of endogenous ATP to maintain an optimal rate of synthesis under the experimental conditions. Copper deficiency does not deplete acyl‐CoA:L‐glycerol‐3‐phosphate acyltransferase (E.C.2.3.1.15.) from either microsomes or mitochondria. The activies of palmitoyl‐CoA hydrolase (E.C.3.1.2.2.) in liver microsomes or liver mitochondria and of palmitoyl‐CoA:carnitine palmitoyl‐transferase in liver mitochondria are not affected by copper deficiency.
GANGLIONIC BLOCKADE BY RHAZIDINE
Authors: Bhattacharya BB , Chaudhuri SK , Ganguly DK
Published: November 2007

Rhazidine, a monoquaternary alkaloid, exhibited considerable ganglion blocking property. Responses of the nictitating membrane to pre‐ganglionic sympathetic stimulation were abolished without affecting post‐ganglionic responses. Responses of the vas deferens to hypogastric nerve stimulation were impaired without altering the responses to intramural stimulation in the guinea‐pig. Only partial inhibition of response was observed in the guinea‐pig urinary bladder to hypogastric nerve stimulation. Spasms induced by nicotine were selectively inhibited in all of the test organs. Effects at adrenergic neuron and post‐synaptic receptors were excluded. The results were compared with pentolinium lartarate and indicated specific ganglion blocking effect of rhazidine.
EFFECTS OF PARATHYROID EXTRACT AND GLYCEROL ON 32P UPTAKE IN RAT RENAL TISSUE
Authors: Geary CP , Cousins FB
Published: November 2007

Parathyroid extract enhanced cellular turnover of 32P in rat kidney in vivo and in vitro. The parathyroid extract contained glycerol, and injected glycerol alone increased the uptake of 32P by renal tissue as much as 50%. Glycerol, but not parathyroid extract, also increased the renal content of phosphorus. Parathyroid extract, a glycerol‐free parathyroid extract, and glycerol all stimulated the uptake of 32P in rat renal cortical slices under aerobic conditions, glycerol having the greatest effect. Separation of phosphate fractions suggested that glycerol and parathyroid extract stimulated the uptake of 32P by different pathways.
THIOL DISTRIBUTION IN THE PLASMAS OF NATIVE AUSTRALIAN MAMMALIA
Authors: Fantl P
Published: November 2007

The thiol concentration in blood plasma was determined by an exchange with di(carboxy‐2‐nitrophenyl)‐5,5′‐disulphide.

The thiol concentration in the plasma of the monotremata:platypus and echidna was lower than in the plasma of the marsupalia: brush‐tail possum, ring‐tail possum, wombat, parma wallaby and native cat. Non‐protein thiol compounds were present, without significant differences, in all the plasmas of the above animals, but the mercaptalbumin concentration of the monotremata was very low, although the total protein and albumin concentration was as high as in the plasma of old world mammalia. The distribution of thiol compounds in the plasma of the marsupalia was similar to that of old world mammalia.

The reactivity of mercaptalbumin of wombat's plasma in the disulphide exchange reaction was practically identical at pH 6·5 and 7·8, whereas the mercaptalbumin of brush‐tail possum plasma showed marked pH dependence. The observed mercaptalbumin characteristics suggest certain phases in the evolution of marsupalia.
QUANTITATIVE ASSAY OF A PROTEIN ANTIGEN OF VIBRIO CHOLERAE INVOLVED IN THE VIBRIOCIDAL ACTION OF ANTIBODY AND COMPLEMENT
Authors: Neoh Sim Hee , Rowley Derrick
Published: November 2007

Protein was separated from carbohydrate in an endotoxin complex by partitioning with phenol‐water. A small portion of the protein of V. cholerae 569B endotoxin was capable of inhibiting the vibriocidal activity of anti‐protein antiserum. The isolated protein preparations each contained several different protein components and comparatively less vibriocidal inhibiting activity against an anti‐protein antisernm than the materials from which they were derived. The common inhibiting protein antigen was found in all the cholera strains tested but in different quantities.
PROLONGED LYMPHOCYTOPENIA IN THE RAT
Authors: Roser Bruce , Ford WL
Published: November 2007

In order to produce a selective deficiency of recirculating small lymphocytes by exploiting their radiosensitivity and unique migration pattern an attempt was made to confine a permanent field of radiation to lymphoid organs. A technique was developed for the direct injection into rat spleens of the β‐emitting isotope 32P in the form of colloidal chromic phosphate. Most of the isotope was retained in the spleen for several weeks. Some reached the liver and the parathymic lymph nodes but the concentration in these and other organs was very low. This procedure was followed by a deficit of lymphocytes both in the blood and in thoracic duct lymph. The rate at which these rats became lymphocytopenic and the tempo of their recovery were Investigated.

Another series of rats was given intrasplenic injections of 185W in the form of tungsten trioxide. This isotope is a pure β‐emitter with a half‐life 5 times longer than 32P, It also produced lymphocytopenia which was much more prolonged than after 32P. A substantial deficit of thoracic duct lymphocyte output was sustained for at least 12 weeks.

After lymphocytopenia had been induced by intrasplenic injection of 185W. splenectomy was performed. Removal of the radioactive focus was followed by a rapid recovery in the blood lymphocyte level. It is argued that the maintenance of lymphocytopenia in isotope infected, rats was due to the Killing of small lymphocytes by radiation during their physiological migration through the radioactive areas of the spleen.

As an alternative to intrasplenic injection, the cervical lymph nodes were injected with 185W. This was less effective in lowering blood lymphocyte levels but was equally as effective as intrasplenic 185W. in lowering thoracic duct output. When an intrasplenic injection of 185W was followed by an intranodal injection of 185W an additional lowering of the blood lymphocyte level was found. Thymectomy performed before combined intrasplenic and intranodal 185W injections had no additional effect on the already low blood lymphocyte levels.

Most rats injected with either 32P or 185W gained weight and showed no abnormality in other blood cells. However, a few rats, which had been given intrasplenic 32P, developed haemolytic anaemia and one rat, after 2 injections of 185W, contracted a transferable lymphocytic leukaemia.
THE ROLE OF MICELLAR SOLUBILIZATION IN LIPID ABSORPTION
Authors: Simmonds WJ
Published: November 2007

Results with everted sacs, in vitro, suggest that lipid uptake is limited by diffusion across an unstirred aqueous layer adjacent to the cell membrane. This step is facilitated by micellar solubilization. There is a linear relation between uptake and concentration of solubilized fatty acid. Bile acids play a non‐specific role as solubilizers since, for the same concentration of solubilized fatty acid, uptake is the same, irrespective of bile acid concentration, and for a different detergent the difference in uptake is consistent with the different micellar diffusion rates. Micellar aggregates carry absorbable lipid up to the cell membrane but lipid ultimately penetrates as single molecules, each type at its own rate. Metabolic events within the absorptive cell, such as resynthesis of triglyceride from absorbed fatty acid and monoglyceride, are affected by the rate of uptake but not, it seems, specifically by the presence or absence of bile acids. Absorption from the whole intestine in vivo does not always seem to fit the model suggested by isolated segments, in vitro. Comparison of results for the same mixture but with varying absorptive situations helps to reconcile some discrepancies. For example, adaptation in the proportion of absorptive area utilized can compensate for variations in absorption per unit area. The physicochemical properties of bile acids are admirably suited to a role as micellar solubilizers under the conditions prevailing in the lumen of tlie small intestine. There is no compelling evidence for an additional, specific role in absorption of fatty acid and monoglyceride. However, a specific requirement for bile acids in cholesterol absorption is suggested, particularly by experiments in vivo.
ABSORPTION AND ENDOGENOUS PRODUCTION OF IMMUNOGLOBULINS IN CALVES
Authors: Husband AJ , Brandon MR , Lascelles AK
Published: November 2007

The changes in the concentration of IgG1, IgG2, IgM and IgA were measured in the blood serum of 7 calves from birth to 18 weeks of age. The previously unsuckled calves were each fed 2 l of their dam's colostrum within the first six hours after birth.

IgG1 and IgG2 were present in low concentrations in the sera of all calves before first suckling, IgM was found in 5 calves and IgA in only 2. Peak serum concentrations of IgM and IgA were observed twelve hours after first feeding colostrum, whereas IgG1 and IgG2 did not reach peak concentrations until twenty four hours. It was estimated that IgM was absorbed with an efficiency of almost 100%. The considerably lower apparent efficiencies of absorption for IgG1 and IgG2 were attributed to loss of these lower molecular weight immunoglobulins into the interstitial fluid.

The initial increase in concentration of all four immunoglobulins was followed by a linear decline during the subsequent 8–16 days; this was taken to represent biological degradation. Regression coefficients for IgG1 and IgG2 were significantly less than those for IgM and IgA, reflecting the more rapid disappearance of IgM and IgA from the circulation.

The results indicated that significant endogenous production of IgG1, IgG2and IgM began 8–16 days after birth and around 64 days for IgA.
SPECIES VARIATION IN GALACTOKINASE ACTIVITY OF ERYTHROCYTES, LENS AND LIVER
Authors: Gupta JD , Irvine Susan , Harley JD
Published: November 2007

Methaemoglobin reduction by erythrocytes from mature humans, rabbits and rats was less rapid with galactose than with glucose as substrate. With galactose, rates of methaemoglobin reduction were approximately equal in human and rat, but considerably less than in rabbit erythrocytes. Galactokinase activity, on the other hand, was greater in rabbit and rat than in human erythrocytes, approximately the same in rabbit and rat erythrocytes, approximately the same in rabbit and rat liver but considerably less in rat than rabbit lens. It is suggested that the differences observed may at least in part determine variation between these species in susceptibility to galactose cataractogenicity.
A MUTANT OF PSEUDOMONAS AERUGINOSA WITH INCREASED CONJUGATIONAL ABILITY
Authors: Pemberton JM , Holloway BW
Published: November 2007

A mutant donor strain of Pseudomonas aeruginosa has been isolated which produces a hundred times more progeny from conjugation than does the donor strain from which it was derived. The mutation fer‐1, carried by this strain is not located on the FP2 sex factor, since transfer of FP2 alone does not result in transfer of the mutant phenotype. Preliminary linkage data suggests that the mutation is chromosomally located although it has not been precisely mapped. Recipient (FP2—) strains displaying the Fer phenotype can be isolated from matings involving fer‐1 donors, and these give a similarly high recombination frequency in matings with both wild type and Fer donors. The fer‐1 mutation apparently enhances the stability of mating pairs since marker entry times in interrupted matings using Fer strains are only obtained if very vigorous agitation is used to disrupt the mating cells. Fer‐1 strains show different precipitability characteristics from the wild type, suggesting that the increased fertility of these mutants is due to a change in the bacterial cell surface.