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PubMed2004

High-level genotypic variation and antibiotic sensitivity among Escherichia coli O157 strains isolated from two Scottish beef cattle farms.

Escherichia coli O157:H7 is a human pathogen that is carried and transmitted by cattle. Scotland is known to have one of the highest rates of E. coli O157 human infections in the world. Two hundred ninety-three isolates were obtained from naturally infected cattle and the environment on two farms in the Scottish Highlands. The isolates were typed by pulsed-field gel electrophoresis (PFGE) with XbaI restriction endonuclease enzyme, and 19 different variations in patterns were found. There was considerable genomic diversity within the E. coli O157 population on the two farms. The PFGE pattern of one of the observed subtypes matched exactly with that of a strain obtained from a Scottish patient with hemolytic-uremic syndrome. To examine the stability of an individual E. coli O157 strain, continuous subculturing of a strain was performed 110 times. No variation from the original PFGE pattern was observed. We found three indistinguishable subtypes of E. coli O157 on both study farms, suggesting common sources of infection. We also examined the antibiotic resistance of the isolated strains. Phenotypic studies demonstrated resistance of the strains to sulfamethoxazole (100%), chloramphenicol (3.07%), and at a lower rate, other antibiotics, indicating the preservation of antibiotic sensitivity in a rapidly changing population of E. coli O157.

Animals↗
PubMed1977

The origin of ventricular arrhythmias 24 hours following experimental anterior septal coronary artery occlusion.

The anterior septal coronary artery was acutely ligated in 16 open-chest anesthetized dogs to produce an infarct of the septal myocardium. Twenty-four hours following occlusion complete epicardial mapping and extensive plunge electrode recording techniques were used to localize the sites of origin and patterns of activation of the ventricular tachyarrhythmias that developed during recovery. The earliest electrical activity for 13 individual rhythms was recorded from surviving septal subendocardial Purkinje fibers at the margins of the infarct, in the right or left ventricle, directly underlying the sites of earliest epicardial breakthrough. The sites of origin were verified by demonstrating unchanged activation sequences during pacing through the electrode sites which recorded the earliest activity. None of the arrhythmias arose from the His bundle or bundle branches despite the fact that these tissues course directly through the necrotic septum. The data presented supports the hypothesis that ventricular arrhythmias occuring in the 24-36 hour post acute infarction period may originate in the surviving subendocardial Purkinje system. Our experimental model shows that in cases in which a malignant rhythm arises from a focus, whether it is due to enhanced automaticity or local re-entry, epicardial mapping alone may not identify the source of the arrhythmias. Extensive endocardial mapping may provide a more rational basis for surgical interventions designed to abolish these arrhythmias.

Animals↗
PubMed1984

The effect of pregnancy on the metabolism of noradrenaline in reproductive organs of the rabbit.

The metabolites of (-)-3H-noradrenaline (1.2 mumol l-1) formed by uteri from non-pregnant mature rabbits were, in descending order of importance, 3H-DOPEG greater than 3H-MOPEG greater than 3H-NMN greater than 3H-VMA (3H-DOMA not measured). The pattern of metabolite formation per unit mass of tissue was markedly different in uteri from 28 day pregnant rabbits due to a fourfold increase in 3H-NMN formation and a fourfold decrease in 3H-DOPEG formation. The effects of cocaine indicated that 3H-NMN was largely extraneuronal in origin and 3H-DOPEG was both neuronal and extraneuronal in origin. The pattern of metabolite formation in pregnant rabbit uteri closely resembled the reported pattern in uteri from ovariectomized rabbits treated with 17 beta-oestradiol and progesterone. In the rabbit oviduct and ovary, the patterns of metabolite formation, and their modification by cocaine, indicated that (-)-3H-noradrenaline was metabolised mainly by intraneuronal deamination in the oviduct and mainly by extraneuronal O-methylation in the ovary. Pregnancy did not affect (-)-3H-noradrenaline metabolism in the oviduct, but decreased the metabolism in the ovary.

Animals↗
PubMed1991

Recovery of circadian rhythm of plasma cortisol levels after a 3-day trip between Tokyo and San Francisco.

The objective of the present study is to investigate the change in the circadian rhythm of plasma cortisol levels following a 3-d trip and a westbound return flight from San Francisco (SFO) to Tokyo. Six healthy male students volunteered for the project. Plasma cortisol levels were monitored 4 times daily for 13 d during the experimental period. In Tokyo, the baseline pattern of cortisol concentrations showed the classical diurnal profile. During the 50-h stay in SFO, phase advancement of 8 h was observed for the initial 32 h. This was followed by a disturbance in the profile for the remaining 18-h period. After returning to Tokyo, the subjects exhibited the original diurnal pattern beginning Day 1. However, complete resynchronization was not apparent until Day 4 after the return.

Adaptation, Physiological↗
PubMed1987

Development of the preoptic area: time and site of origin, migratory routes, and settling patterns of its neurons.

Neurogenesis and morphogenesis in the rat preoptic area were examined with [3H]thymidine autoradiography. For neurogenesis, the experimental animals were the offspring of pregnant females given an injection of [3H]thymidine on two consecutive gestational days. Nine groups were exposed to [3H]thymidine on embryonic days E13-E14, E14-E15, E21-E22, respectively. On postnatal day P5, the percentage of labeled cells and the proportion of cells originating during 24-hr periods were quantified at four anteroposterior levels in the preoptic area. Throughout most of the preoptic area there is a lateral to medial neurogenetic gradient. Neurons originate between E12-E15 in the lateral preoptic area, between E13-E16 in the medial preoptic area, between E14-E17 in the medial preoptic nucleus, and between E15-E18 in the periventricular nucleus. These structures also have intrinsic dorsal to ventral neurogenetic gradients. There are two atypical structures: (1) the sexually dimorphic nucleus originates exceptionally late (E15-E19) and is located more lateral to the ventricle than older neurons; (2) in the median preoptic nucleus, where older neurons (E13-E14) are located closer to the third ventricle than younger neurons (E14-E17). For an autoradiographic study of morphogenesis, pregnant females were given a single injection of [3H]thymidine during gestation, and their embryos were removed either two hrs later (short survival) or in successive 24-hr periods (sequential survival). Short-survival autoradiography was used to locate the putative neuroepithelial sources of preoptic nuclei, and sequential survival autoradiography was used to trace the migratory waves of young neurons and their final settling locations. The preoptic neuroepithelium is located anterior to and in the front wall of the optic recess. The neuroepithelium lining the third ventricle is postulated to contain a mosaic of spatiotemporally defined neuroepithelial zones, each containing precursor cells for a specific structure. The neuroepithelial zones and the migratory waves originating from them are illustrated. Throughout most of the preoptic area, neurons migrate predominantly laterally. The older neurons in the lateral preoptic area migrate earlier and settle adjacent to the telencephalon. Younger neurons migrate in successively later waves and accumulate medially. The sexually dimorphic neurons are exceptional since they migrate past older cells to settle in the core of the medial preoptic nucleus.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed2001

Origin and conservation genetics of the threatened Ute ladies'-tresses, Spiranthes diluvialis (Orchidaceae).

The Ute ladies'-tresses, Spiranthes diluvialis, is listed as a threatened orchid in west-central United States by the Federal government. Information on its origin and patterns of genetic variation is needed to develop effective conservation strategies for this species. DNA sequencing and polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was used to evaluate genetic variation and structure of 23 populations of S. diluvialis. In addition, four congeneric species were analyzed to determine possible origins of the putative allotetraploid S. diluvialis. DNA sequencing and PCR-RFLP analysis of the nuclear ribosomal internal transcribed spacer (ITS) and mitochondrial and chloroplast DNA noncoding regions revealed no genetic variation within or among populations of S. diluvialis. DNA sequencing revealed that S. diluvialis has rDNA of both S. magnicamporum and S. romanzoffiana, supporting the proposed origin of the allotetraploid. Parsimony and maximum likelihood analyses of cpDNA and mtDNA sequences revealed that these S. diluvialis organellar sequences were most closely related to those of S. romanzoffiana, providing evidence that the latter species is the maternal parent of S. diluvialis. The lack of genetic diversity is significant for the development of a long-term conservation strategy for S. diluvialis.

Journal Article↗
PubMed1997

The STR252-IVS10nt546-VNTR7 phenylalanine hydroxylase minihaplotype in five Mediterranean samples.

IVS10nt546 (IVS10nt-11g-->a) is the most common molecular defect of the phenylalanine hydroxylase gene causing phenylketonuria in Mediterranean populations. Previous studies have proposed various and alternative hypotheses concerning the geographical origin and pattern of diffusion of this mutation in this area. In this study, this issue was re-examined on a large sample (149) of "Mediterranean" IVS10nt546 mutant alleles analysed with multiallelic intragenic polymorphisms. The analysis of intragenic microsatellite (STR) and minisatellite (VNTR) polymorphisms shows allelic heterogeneity of the IVS10nt546 mutation. Eight STR and three VNTR alleles were found in association with the splicing defect. Of the ten detected STR-VNTR combinations ("minihaplotypes"), we identified a predominant allelic association (VNTR7-STR252) embedded in a RFLP-haplotype 6 background, which seems to correspond to the ancestral gene originating in the Turkey-Israel area. Analysis of both absolute and relative gene frequencies of the STR252-IVS10nt546-VNTR7 minihaplotypes, shows statistically significant (P < 0.02) variations and may suggest gene flow from Turkey and/or Israel to Italy and Spain. The associated migratory events need not be unique in time (and people) but seem to suggest they may be traced back to the expansion of the Neolithic culture and people, thus allowing dating of the origin of this mutation to at least 5000-10000 years ago. Alternative hypotheses are discussed to explain, in light of the available historical and pre-historical evidence, the pattern of diffusion of the IVS10nt546 mutation in the Mediterranean basin.

Gene Frequency↗
PubMed1990

Bone-only versus visceral-only metastatic pattern in breast cancer: analysis of 150 patients. A GOCS study. Grupo Oncológico Cooperativo del Sur.

The medical records of 510 patients with metastatic breast cancer were retrospectively reviewed. Seventy-seven patients with metastases confined to skeleton and 73 patients bearing visceral-only disease were identified. All patients had a disease-free interval greater than or equal to 6 months and received systemic therapy with any of the following modalities: chemotherapy, hormonotherapy, or chemohormonotherapy. The clinical features, response to treatment, and survival were analyzed and compared for both groups. Median survival of patients with osseous metastases was 28 months, while it was 13 months for those patients with a visceral pattern (p less than 0.001). Response rates to first and second line systemic therapy for both metastatic patterns showed no significant differences, suggesting a similar degree of sensitivity or resistance in both groups. Objective regression to first therapy was 45% in the group with bony disease and 41% among patients with visceral involvement; median duration of response was 16 months and 13 months, respectively. In both groups progressive disease conserved the original metastatic pattern in most patients. We conclude that although a superiority in survival was evident for the osseous metastatic pattern, for these patients efforts should be made to select the least aggressive therapy in order to avoid excessive toxicity. Further studies are needed to confirm our findings.

Adenocarcinoma↗
PubMed1999

Malignant myxoid endobronchial tumour: a report of two cases with a unique histological pattern.

AIMS: To present two cases of malignant endobronchial myxoid tumours with a highly distinctive sarcomatoid pattern not previously described at this site, and discuss their histogenesis in relation to previously documented endobronchial neoplasms. METHODS AND RESULTS: Both tumours presented in young adult females and were purely sarcomatoid with interweaving cords of small uniform, rounded or slightly elongated cells lying within a myxoid stroma. The stroma was alcian blue positive, but sensitive to hyaluronidase in both cases. The tumour cells contained a small volume of periodic acid-Schiff-positive eosinophilic cytoplasm and stained positively for vimentin only, but there also was a prominent background population of CD68-positive dendritic cells. Ultrastructural studies showed that the tumour cells contained an excess of rough endoplasmic reticulum, with some of the cisternae appearing dilated, and scalloping of the cell surfaces, although no intracisternal tubules were identified. CONCLUSIONS: Although the histological pattern was most reminiscent of extraskeletal myxoid chondrosarcoma, the sensitivity of the stroma to pretreatment with hyaluronidase precluded the diagnosis. However, there were similarities with the sarcomatoid component of malignant salivary gland-type mixed tumours of the lung and this tumour possibly represents a variant of a bronchial gland tumour. Despite this uncertainty over origin, this pattern should be recognized as part of the differential diagnosis of myxoid tumours in the lung, as an apparently indolent type of malignant endobronchial neoplasm.

Adult↗
PubMed2003

Monophyletic clade of HIV-1 subtype B in Korea: evolutionary pressure or single introduction?

We have previously shown that many of the nef sequences from Korean HIV-1 subtype B carriers were grouped together in phylogenetic tree analyses. To determine whether this pattern was originated from either a single HIV-1-infected person or some biological pressure which directs the HIV-1 genomic mutation by the Korean specific immunological characters, we analyzed nef sequences from HIV-1-infected individuals with different time intervals. Thirty-two out of 46 analyzed patients formed a Korean monophyletic (KM) clade with 93% bootstrapping value. Eighteen patients' nef sequences were analyzed 1-9 years after first analysis. None of the patients shifted their clade from the first clustered clade (KM or non-KM), and all of the re-analyzed isolates were clustered close to the first analyzed clade. Isolates of the KM dade and non-KM clade in nef analysis showed the same pattern as in env analysis. Phylogenetic clustering evidences from both nef and C2/V3 trees strongly support the idea that introduction of the KM clade in subtype B strains originated from a common source. Thus, treatment and development of an AIDS vaccine may be somewhat easier than in other countries with multiple strains of HIV-1.

Biological Evolution↗
PubMed1975

The problem of the origin of fibroblasts in the postnatal ontogenesis of mammals.

An analysis is made of the author's data and the literature information on the origin and patterns of differentiation of the fibroblasts of connective tissue during the postnatal ontogenesis of mammals. The hypothesis of the existence of two types of collagen-producing cells (fibroblasts) - protective-trophic (short-lived population) and supporting (long-lived population) - is substantiated. Hypotheses are advanced on the biological role of these types of fibroblasts and their origin in phylogenesis.

Animals↗
PubMed1991

The role of pacemaker properties and synaptic input in generation and modulation of spiking activity in a pair of electrically coupled peptidergic neurons.

The origin of patterned electrical activity in two electronically coupled peptidergic neurons, VD1 and RPD2, in the CNS of Lymnaea stagnalis was investigated. VD1 proved to have intrinsic beating pacemaker properties. Hybrid current/voltage clamp experiments demonstrated that in the intact CNS generation of spike activity in the coupled cell system is dominated by VD1. Modulation of spiking activity of VD1/RPD2 appears to originate mainly from chemical synaptic input. The electrical coupling of VD1 and RPD2 proved essential for spike synchronization between the cells.

Action Potentials↗
PubMed1989

Assessment of the role of the immunoglobulin isotypes in the development of diabetic nephropathy in untreated streptozotocin-induced diabetic rats.

Thirty of 45 (67%) streptozotocin-induced male Sprague-Dawley diabetic rats developed microalbuminuria that progressed to overt proteinuria with increased concentrations of IgG in their urine. 33% (15/45) never developed albuminuria or IgG proteinuria. These percentages did not correlate with glucose control since none of the animals were treated with insulin and all demonstrated the same degree of hyperglycemia. Indirect immunofluorescent antibody staining of frozen tissue sections from the kidneys of rats that developed overt proteinuria stained for IgM (67%), C3 (93%), IgG2b (93%) and IgG2c (60%). Non-proteinuric diabetic kidneys stained for IgM (80%), C3 (67%) IgG2b (67%) and IgG2c (87%). Control kidney sections demonstrated no consistent staining pattern. The occurrence and concentration of the different immunoglobulin isotypes, eluted from frozen sections with immune complex dissociating buffers, mimicked that which was observed by immunofluorescence. When urine or serum from the same rat or a rat of a different group was incubated with kidney sections eluted of all immunoglobulin, indirect immunofluorescent staining demonstrated antibody activity corresponding to the original staining pattern observed for each animal group prior to elution. The most consistent observation was that the diabetic rats that developed proteinuria were positive for IgG2b staining in their kidney sections; whereas, those that did not develop proteinuria stained predominantly for IgG2c. From this data, we suggest that the progression of diabetic nephropathy may depend on whether a specific IgG subclass response is elicited.

Animals↗
PubMed1998

Peptidergic innervation of the rat cornea.

Corneal nerves regulate corneal epithelial integrity, proliferation, and wound healing. The mechanisms by which the nerves mediate their effects remain poorly understood; however, the release of biologically active neuropeptides has been hypothesized. The purpose of the current investigation was to determine the relative densities, distribution patterns, and origins of rat corneal nerves containing each of eight different neuropeptides, calcitonin gene-related peptide (CGRP), substance P (SP), galanin (GAL), neuropeptide Y (NPY), methionine-enkephalin (M-ENK), vasoactive intestinal polypeptide (VIP), somatostatin (SOM), and cholecystokinin (CCK). In the first set of experiments, immunohistochemical demonstrations of the above neuropeptides were performed on free-floating corneal sections cut tangential to the corneal surface. The results showed that six of the peptides, CGRP, SP, GAL, NPY, M-ENK, and VIP were present in rat corneal nerves. The innervation patterns of corneal nerves containing each of these six peptides were then documented by mapping all fibers in serial sections from select corneal quadrants onto a series of line drawings by using a drawing tube. In the second set of experiments, the origins of the corneal peptidergic nerve fibers were determined by selective ocular denervations. Unilateral combined sensory and sympathetic ocular denervations or unilateral sympathetic ocular denervations were performed in adult rats by transecting the ophthalmomaxillary nerve and/or removing the superior cervical ganglion. After 5-7 days, each of the ipsilateral corneas was sectioned and processed immunohistochemically for the presence of one of the six peptides found in experiment one, and the fibers that survived the ocular denervations were plotted onto line drawings. Ocular denervations revealed that corneal peptidergic nerves have sensory (CGRP, SP, and GAL), sympathetic (NPY), and parasympathetic (GAL, NPY, M-ENK, and VIP) origins. The results of this investigation have shown that the peptidergic innervation of the rat cornea is more extensive and complex than previously reported. This is the first investigation to show the presence of GAL in the rat cornea, and the first to demonstrate the presence of NPY-, VIP-, and M-ENK-IR nerve fibers in the cornea of any species.

Animals↗
PubMed1980

Regeneration of rabbit ear tissue.

Holes punched in the ears of rabbits are repaired by regeneration of new tissues from blastemas found on the periphery of the wounds. The proportion whch successfully regenerated was greater in males than in females (75% vs 20%), in pregnancy than during etrus or lactation (75% vs 25%), and in ovariectomized does given testosterone than in those given oil carrier alone (88% vs 50%), but the speed of closure did not differ in these groups. The steroid hormone influence postulated by other workers is confirmed. Closure was faster in younger animals and for second holes punched on the same site where earlier holes had been repaired, in both cases, by shortening of the initial seven to ten day delay period seen for primary holes in adult ears. The cartilage layer was also thicker after regeneration from secondary punches and the success rate greater (67% vs 29%). These observations suggest a "priming" effect on the tissue from the primary punch. Ear holes in the area proximal to the head were repaired faster and with more success (78% vs 12%) than those punched distally. The relative thickness of the cartilage layer may be the critical factor. Tissues did not regenerate from semicircular layer may be the critical factor. Tissues did not regenerate from semicircular wounds made on the edge of the pinna. Hair grown on regenerated ear skin reestablished the original color pattern. Skin regenerating for hles punched where skin from the back had been transplanted to ears had the characteristics of back skin, but no regeneration was detectable from transplanted toe tissue. Skin from other locations can regenerate in the environment provided by the ear but more complex tissue structures put into the same locatin apparently cannot. Skin cells involved in regeneration originate from the tissues bounding the wound.

Age Factors↗
PubMedDate not supplied

[Family models and mental anorexia. Part I. Patterns in patient's family origin].

The paper presents family models which associate the development of anorexia nervosa with the specific functioning of the patient's family of origin. The described conceptions are based on systems theory which assumes circular conception of family relations. This allows for avoiding one-sidedness of approach, i.e. perceiving a patient as a victim of the family system. In fact, these models emphasize the patient's part in the specific "game" taking place within the family. The conceptions indicate a number of characteristic patterns of relations between the patient's parents as a married couple as well as between the patient and her parents, which, in the period of adolescence become the source of a crisis that assumes the form of anorexia nervosa. The presented approach, focussed on an analysis of family relations, does not question the importance of other aetiological factors. It only points out that the dynamics of mutual relations within a family is an important mechanism influencing the development of the patient's identification and her psychosexual role as well as the course of the separation/individuation process. These aspects seem pivotal for understanding and treatment of anorexia nervosa.

Anorexia Nervosa↗
PubMed1978

Protein composition of cockroach muscles: identification of candidate recognition macromolecules.

The protein composition of each of the coxal depressor muscles from the leg of the cockroach, Periplaneta americana, was analyzed by SDS polyacrylamide gel electrophoresis. The proteins from each muscle were fractionated according to their extractability in Ringer's solution, 1% Triton X-100 and 1% SDS. The gel protein patterns of the fractionated muscles revealed some biochemical differences that could be correlated with mechanical and ultrastructural differences observed among the muscles. In addition, proteins were detected that were considered to be candidate recognition macromolecules that are responsible for the intercellular recognition process that enables regenerating motor neurons to specifically recognize and make stable, functional connections only with the muscles to which they were originally connected. The major evidence for this identification of candidate recognition macromolecules was that their presence in the muscle could best be correlated with innervation by an identified motor neuron. In addition, these proteins remain present in denervated muscles for at least as long as it takes for the original innervation pattern to be reformed by the regenerating motor neurons.

Actins↗