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Changing RNA patterns in rotaviruses of human origin: demonstration of a single dominant pattern at the start of an epidemic and various patterns thereafter.

The RNA of strains of rotavirus obtained from patients hospitalized with diarrhea during two winter epidemics of rotaviral infection in successive years (November 1981 through April 1982 and December 1982 through April 1983) was analyzed by polyacrylamide gel electrophoresis. A single dominant electropherotype was found during the first two or three months of each epidemic. In contrast, various electropherotypes were identified during the latter portion of each epidemic. RNA patterns of the rotaviral strains that were dominant during the early phase of the two epidemics were different from each other.

Diarrhea↗

Prolonged fevers of unknown origin in children: patterns of presentation and outcome.

OBJECTIVE: To review the presentation, clinical characteristics, and outcome of children with prolonged fevers of unknown origin who are referred for pediatric rheumatologic evaluation. METHODS: We used a retrospective review of the charts of the 40 children (23 boys and 17 girls, aged 9 months to 14.6 years) with fevers persisting longer than 1 month who were referred to the Pediatric Rheumatology Clinic between 1984 and 1994, in whom evaluation did not result in diagnosis. Follow-up with children's families, pediatricians, or both was done by telephone. RESULTS: Of the 40 children, 29 had periodic fevers, and 11 had daily fevers without pattern. Patients with periodic fever were younger at onset, had longer duration of symptoms before referral, and higher maximum temperatures. The two groups did not differ in frequency of associated symptoms or signs. At follow-up (mean 60.5 +/- 5 months, n = 37), 10 children with daily fevers (within 24 months) and 23 children with periodic fevers (within 48 months) had completely recovered; three patients continue to have periodic fevers. In patients with daily fevers one had Crohn disease (7 months after initial evaluation) and another had uveitis (4 years after evaluation). One patient with periodic fevers had inflammatory bowel disease 3.5 years after the onset of fevers. Petit mal seizures developed in one patient with periodic fever, and another had mitochondrial encephalopathy. Four children with periodic fevers have attention-deficit hyperactivity disorder, and two have developmental delays. CONCLUSIONS: Fevers without an obvious source usually have a benign outcome, although patients should be monitored for changes in symptoms. Of the children with periodic fevers, 29% were later found to have neurologic problems; the relation to the previous fevers is uncertain.

Adolescent↗

Leukemoid reaction, bone marrow invasion, fever of unknown origin, and metastatic pattern in the natural history of advanced undifferentiated carcinoma of nasopharyngeal type: a review of 255 consecutive cases.

PURPOSE: This study is an analysis of frequency and relationship regarding two undifferentiated carcinoma of nasopharyngeal type (UCNT)-associated paraneoplastic syndromes (PNS): leukemoid reaction (LR) and fever of unknown origin (FUO) with bone marrow invasion (BMI) and metastatic pattern. PATIENTS AND METHODS: A consecutive UCNT patient cohort (N = 255) with locally advanced (n = 142) or metastatic (n = 113) disease receiving chemotherapy alone or in combination with radiotherapy was studied. All patients had a complete baseline work-up that included bone marrow biopsy. RESULTS: UCNT has distinctive features among head and neck squamous cell cancers (HNSCC). These include early subclinical dissemination, with 70% of metastases appearing within 18 months of first symptoms. Metastases are common in bone (65% v 25% in HNSCC), liver (29% v 23%), and lung (18% v 84%), and BMI is observed in 25% of UCNT patients with metastases. Metastases likelihood is related to lymph node involvement, with 64% of patients with metastases having N3 disease. Involved lymph nodes in contrasted CT scans revealed hypodensity in 26% of UCNT patients versus 79% in patients with other HNSCC. Hypercalcemia was observed in one case. LR was identified in 41 patients (16%); in 26 of the 41 patients (64%) it was observed concomitant with N3 and/or metastatic disease. FUO was found in 23 patients (9%) and was associated in four instances with BMI and in 17 with LR (in four instances with both). Brain metastases or meningeal carcinomatosis were not observed despite the high rate of skull base compromise. Paraneoplastic signs were observed in 47 of 255 cases (18.5%) and were more frequent in patients with metastases. However, PNS were observed in 15 patients with negative metastases work-up. CONCLUSION: The PNS described could help in the diagnosis and follow-up of UCNT patients because they may be the first manifestation of the disease or may reappear with relapse. BMI is a frequent finding in patients with metastases and is unrelated to PNS.

Adolescent↗

Breeding origin and migration pattern of dunlin (Calidris alpina) revealed by mitochondrial DNA analysis.

The large-scale migration of birds has been studied extensively by recoveries of ringed birds. However, there is very little ringing data from the arctic breeding grounds of waders. Here, the migration pattern of the dunlin, Calidris alpina, is studied with population genetic markers, using haplotype frequencies to estimate the breeding origin of migrating and wintering populations. Polymerase chain reaction (PCR) and restriction analysis of DNA from the mitochondrial control region was used to study the breeding origins of morphologically similar winter populations in the western Palaearctic, and to describe the population structure of the dunlin during winter. Also migrating dunlin from various stopover sites in Europe, Africa and Asia, were analysed with respect to their mitochondrial DNA (mtDNA) haplotypes. The genetic markers clearly show that the dunlin has a parallel migration system, with populations breeding in the western Palaearctic wintering mainly in the western part of the wintering range, and dunlin populations breeding further east wintering further east. The results also show that the distance between breeding and wintering area increases eastwards in this region.

Animals↗

Prevalence, male germ-line origin and new patterns of inversions in haemophilia A.

Following the discovery of the FVIII gene inversion by Lakich et al. [1] and Naylor et al. [2], we have investigated this mutation in 108 French and Algerian severe haemophilia A patients. We have found that only 29 severe haemophiliacs (27%) exhibited the rearrangement whereas Lakich et al. [1] and Naylor et al. [2] respectively estimated the inversion frequency at 47% and 42% in severe haemophiliacs. The reason for this discrepancy is not accounted for. In this study, we observed two novel patterns of inversions as yet unreported. We did not find any correlation between the presence of the inversion and a particular RLFP haplotype, or ethnic origin, or the absence of a FVIII inhibitor. Among the cases with the inversion, the proportion of sporadic and transmitted cases was roughly equivalent and we also confirm that the inversion occurs preferentially in the male germ-line.

Algeria↗

Aminoglycoside resistance patterns of Serratia marcescens strains of clinical origin.

Aminoglycoside resistance patterns of 147 Serratia marcescens strains of clinical origin were studied. All strains analysed belonged to three different bacterial populations. The periods of study and the institutions the strains were isolated from correlated significantly with the resistance patterns shown by the strains. The most frequent resistance patterns found were the following: ACC (6')-I at the Hospital Infantil de México (Children's Hospital of México), and ANT (2'') + AAC(6')-I at the Instituto Nacional de Pediatría (INPed or National Institute of Pediatrics) in Mexico City. Furthermore, the isolation frequency of aminoglycoside-sensitive strains decreased remarkably at the INPed over a 12-year period. These results suggest that there has been a selection of Serratia marcescens strains that are very resistant to aminoglycosides.

Aminoglycosides↗

Molecular investigation of the progenitors, origin and domestication patterns of diploid Chinese old garden roses.

BACKGROUND AND AIMS: Chinese old garden roses are major contributors to the genetic development of modern roses. The RoKSN gene is associated with continuous flowering in roses and is proposed to have originated from Chinese wild roses. However, the wild roses that are implicated in the breeding of Chinese old garden roses and the origin of the RoKSN locus remain unidentified. We collected 25 of the most renowned and classic diploid Chinese old garden roses along with all related wild roses from East Asia. These roses were analysed with the aim of identifying the wild species that contributed to the genetic composition of Chinese old garden roses. In addition, we aimed to infer the geographical origin of the RoKSN gene and to develop a schematic overview of hybrid domestication of Chinese old garden roses. METHODS: We compared the haplotypes of internal transcribed spacers (nrITS), six nuclear single-copy genes and three chloroplast genes between Chinese old garden roses and wild roses. Additionally, we assessed genetic organization using 21 expressed sequence tag-simple sequence repeats to identify potential donor species that contributed to the emergence of these cultivars. Primers were designed for RoKSN to allow comparison of the gene across the entire distribution range of Rosa sect. Chinenses. KEY RESULTS: Our findings confirmed that the majority of rose cultivars are descendants of early hybridization events. Rosa chinensis var. spontanea, R. odorata var. gigantea and R. multiflora var. cathayensis were the primary donors for the 25 cultivar roses. Chinese old garden roses were categorized into four groups. Ten cultivars were hybrids between R. chinensis var. spontanea and R. multiflora var. cathayensis, thereby forming the 'Old Blush' group. Five cultivars were hybrids between 'Old Blush' and the R. kwangtungensis species complex, thereby forming the 'Slater's crimson' group. Six cultivars were hybrids between 'Old Blush' and R. odorata var. gigantea, thereby forming the 'Tea Rose' group, and three cultivars were hybrids that evolved from more than three donors. Moreover, we observed relatively close genetic proximity among Chinese old garden roses with an identical RoKSN-copia gene that is responsible for continuous flowering, which indicates a single origin for this retrotransposon-containing allele. Additionally, we determined that the haplotypes of the RoKSN-copia gene predominantly occurred in the Sichuan Basin region. In contrast, R. chinensis cultivated in the Ya'an region showed no markers of hybridization and displayed a genetic composition that was close to that of the wild species R. chinensis var. spontanea. This cultivar may represent the earliest mutated individual that bears the RoKSN-copia gene and may have served as a bridge from wild species to continuous-flowering old rose cultivars. CONCLUSIONS: The study provides crucial evidence that elucidates the origin of cultivated roses and lays the groundwork for further analysis of the breeding history of Chinese old garden roses using genomic data.

Domestication↗

Origin and developmental patterns of lactase and other glycosidases in sheep amniotic and allantoic fluid.

Intestinal lactase activity (with its associated cellobiase, 4-methylumbelliferyl-beta-galactosidase and -beta-glucosidase activities) was used as a specific intestinal marker enzyme to study the release of protein and enzymes of intestinal origin in sheep amniotic fluid during gestation. In amniotic fluid, intestinal lactase activity peaked at 66--85 days of gestation and then decreased with gestation. This enzyme activity was very low or absent in allantoic fluid throughout gestation suggesting that there is no important transfer of amniotic fluid lactase towards the allantoic cavity. Maltase and 4-methylumbelliferyl-alpha-glucosidase showed no statistically significant variation with gestation in both amniotic and allantoic fluid whereas alpha-galactosidase and N-acetyl-beta-hexosaminidase which were first higher in allantoic than in amniotic fluid increased in amniotic fluid to reach allantoic fluid levels near term. Such patterns are consistent with the suggestion that the fetal urine is a source of alpha-galactosidase and N-acety-beta-hexosaminidase activities and that sheep urine is first accumulated in the allantoic sac via the urachus up to 86--90 days of gestation and thereafter passes more and more into the amniotic sac.

Allantois↗

Mitochondrial DNA cleavage patterns distinguish independent origin of Chinese domestic geese and Western domestic geese.

It has generally been assumed, based on morphology, that Chinese domestic goose breeds were derived from the swan goose (Anser cygnoides) and that European and American breeds were derived from the graylag goose (Anser anser). To test the validity of this assumption, we investigated the mtDNA cleavage patterns of 16 Chinese breeds and 2 European breeds as well as hybrids produced between a Chinese breed and a European breed. After 224 mtDNAs, isolated from the Chinese and European breeds, were digested by 19 restriction endonucleases, variations of the cleavage patterns were observed for four enzymes (EcoRV, HaeII, HincII, and KpnI). All Chinese breeds and their maternal hybrids except the Yili breed showed an identical haplotype, named haplotype I or the Chinese haplotype; the European breeds and the Yili breed showed another haplotype, named haplotype II or the western haplotype. None of the haplotype found in the Chinese type was detectable in the western type and vice versa. The two haplotypes were found to differ from each other at 8.0% of the sites surveyed and with a 0.72% sequence divergence. Using 2% substitution per million years calibrated from the genera Anser and Branta, the two domestic geese haplotypes were estimated to have diverged approximately 360,000 years ago, well outside the 3000-6000 years in domestic history. Our findings provide the first molecular genetic evidence to support the dual origin assumption of domestic geese in the world. Meanwhile, the four mtDNA restriction fragment length polymorphisms can be used as maternal genetic markers to distinguish the two types of domestic geese.

Animals↗

On the nature of IgG dimers. II. Idiotype--anti-idiotype complexes of polyclonal and monoclonal origin: size distribution patterns and molecular geometries.

Electron micrographs of a fraction containing dimers isolated from pooled human polyclonal immunoglobulin G (IgG) suggest essentially a cyclic geometry compatible with bivalently associated monomers. It is obvious that such a structure can be produced by idiotype (Id)--anti-idiotype (anti-Id) interactions where the latter are able to neutralize certain combining site related Id functions. Accordingly, antibody (ab) activities against tetanus toxoid (tt) and rubella antigen (ag) were found to be almost exclusively confined to the monomeric molecules in preparations composed of monomers and dimers only. Moreover, electron micrographs of complexes prepared from a murine monoclonal Id as well as anti-Id reveal the presence of ring complexes, especially of cyclic tetramers. Gel filtration patterns of mixtures containing equimolar concentrations (concns) of such abs (1.6 x 10(-6) M) show, correspondingly for 9 different Id--anti-Id pairs and therefore probably representing a more common feature, mainly the formation of even-numbered complexes, especially tetramers. That is basically in accordance to an equilibrium model developed by Archer and Krakauer but not from a quantitative point of view because non-ideality terms had not been originally included. Despite taking strain energies determined by Schumaker et al. for cyclic complexes of polyclonal rabbit abs and a bivalent hapten into account for computation of size distribution patterns, the predominant formation of dimers was, nevertheless, again predicted by the modified theory in contrast to the experimental results. Fundamental conformity could only be achieved by further decreasing one of the statistical factors, namely the ring closing factor, which theoretically influences the generation of cyclic dimers. Therefore, referring to the experimental results of Schumaker et al., we postulate a strain energy well above 700 cal/mol for cyclic dimers produced by interacting Ids and anti-Ids. In general, the findings confirm predictions based on the interpretation of recent kinetic studies.

Animals↗

The luminance origin of the pattern electroretinogram in man.

Electroretinograms (e.r.g.s) and visually evoked potentials (v.e.p.s) to pattern stimuli were recorded simultaneously from healthy subjects. The stimuli were produced by a configuration in which the luminance of two sets of spatial elements (checks) could be modulated independently. Experiments were designed to distinguish between contrast responses and non-linear luminance responses. In the first of two basic experiments, the luminance of only one set of checks was modulated, at a constant level in every trial. The other set was not modulated, but its luminance was set at various levels. Under these conditions the local luminance stimulation was kept equal for every trial whereas the contrast stimulation varied. Therefore, local luminance responses in these experiments were expected to be constant and contrast responses were expected to vary. The e.r.g.s were identical for all luminance settings of the unmodulated checks, suggesting that luminance rather than contrast determines the response. The v.e.p.s showed, on the contrary, the behaviour expected for contrast responses. In the second basic experiment the local luminance stimulation was also kept constant, but the phase difference between the modulations of the two sets of checks was varied between 0 deg (pure luminance stimulation) and 180 deg (pattern reversal). In this type of experiment the second harmonic responses to local luminance modulation are expected to decrease to a minimum as phase difference goes from 0 to 90 deg and increase again as phase difference goes to 180 deg. Contrast responses are expected to increase monotonically from zero to maximal at phase difference shifts from 0 deg (no contrast stimulation) to 180 deg (contrast reversal). The e.r.g.s decreased to a minimum at 90 deg phase difference and increase again with phase difference going to 180 deg. At 0 and 180 deg the same value was recorded. Consequently, the e.r.g. behaviour suggests a luminance origin of the responses. The v.e.p.s monotonically increased as phase difference went from 0 to 180 deg, thus suggesting a contrast origin of the responses. Two additional control experiments were performed. The first experiment compared the responses to homogeneous field red/green exchange and pattern red/green exchange, with the luminances of the red and green sources matched by heterochromatic flicker photometry. The exchange of luminance-matched red and green checks (pattern reversal) did not produce different e.r.g. responses from those recorded in response to homogeneous field red/green exchange. The v.e.p. showed a significant increase for the pattern stimulus.(ABSTRACT TRUNCATED AT 400 WORDS)

Color Perception↗

An autoradiographic study of the time of origin and the pattern of granule cell migration in the dentate gyrus of the rat.

The dentate gyrus of the rat contains about 600,000 granule cells. These small neurons are generated over a prolonged period from the 14th day of gestation until some time after the second postnatal week. The majority of the cells pass through their last phase of DNA synthesis in the postnatal period, and during the peak period of cell generation, between the fifth and seventh days after birth, up to 50,000 granule cells are formed each day. Contrary to earlier reports, most of the cells pass through their last mitotic division either within the stratum granulosum itself, or within the hilar region of the developing gyrus. The precursor population of cells in the hilar region must therefore constitute a pool of true neuroblasts. The origin of this pool of cells has not been definitely established but it seems probable that its cells are derived from the neuroepithelium lining the lateral ventricle adjacent to the region from which the hippocampal pyramidal cells are generated. Examination of the final location of granule cells labeled at different stages reveals three distinct morphogenetic gradients in the gyrus. The cells in the dorsal blade tend to be formed earlier than those in the ventral blade; cells in the more caudal (or temporal) portions of the gyrus are generated earlier than those in more rostral (or septal) regions; and in all regions the more superficial neurons in the stratum granulosum are formed earlier than the deeper granule cells. The bearing of some of these findings on the development and organization of the connections of the dentate gyrus is discussed.

Animals↗

Dorsal nerve root origins of the cutaneous nerves of the feline pelvic limb.

The dorsal root origins of cutaneous nerves supplying the feline pelvic limb were determined electrophysiologically in 11 cats. Cutaneous nerves were surgically exposed and the presence or absence of an evoked potential in response to stimulation of individual dorsal roots was noted. The dorsal cutaneous branches of L3-L5 and S3, and the lateral cutaneous branch of L3 each arose solely from their parent spinal nerves. The L7, S1, and S2 dorsal cutaneous branches had multiple dorsal root origins. The lateral cutaneous femoral nerve originated from L3-L6 dorsal roots in 4 patterns of origin, and the saphenous nerve originated from L4-L6 dorsal roots in 2 patterns of origin. The lateral and caudal cutaneous sural nerves originated from L6-S1 roots in 2 and 3 patterns, respectively. The lateral and medial plantar nerves arose from L6-S2 roots in 4 and 2 patterns, respectively. The superficial and deep peroneal nerves originated from L6-S1 roots in 2 and 3 patterns, respectively. The caudal cutaneous femoral nerve or its branches arose from L7-S3 in 8 origin patterns. The dorsal nerve of the penis and the superficial perineal nerve arose from L7-S3 and S1-S3 roots, respectively, each in 4 patterns. A subtle correlation between plexus type and dorsal root origins of the cutaneous nerves was noted.

Animals↗

Siliceous spicules and skeleton frameworks in sponges: origin, diversity, ultrastructural patterns, and biological functions.

Silica deposition is a fundamental process in sponges. Most sponges in the Classes Demospongiae and Hexactinellida secrete siliceous elements, which can subsequently fuse, interlock with each other, or form three-dimensional structures connected by spongin. The resulting skeletal frameworks allow sponges to grow upwards and facilitate water exchange with minimal metabolic cost. Several studies on sponge skeletogenesis have been published. We are beginning to understand the mechanisms of spicule secretion and the role of spicules and skeletal frameworks in the biology, ecology, and evolution of sponges. Molecular techniques and ecological experiments have demonstrated the genetic control of the process and the contribution of environmental factors to the expression of a sponge spicule, respectively. However, other classic topics such as the role of membranes in silicon transport or whether spicules are formed in situ or secreted anywhere in the sponge mesohyl and then transported to the skeletal framework require further investigation. We review the process of silica deposition in sponges at the molecular and cellular levels, as well as the biological and ecological functions of spicules and skeletons. The genetic control of spicule shapes makes them useful in the reconstruction of sponge phylogeny, although recent experiments have demonstrated the influence of environmental factors in modulating spicule size, shape, and the presence or absence of one or more spicule types. The implications of such variations in sponge taxonomy may be important. Besides supporting sponge cells, spicules can help larvae stay buoyant while in the plankton or reach the bottom at settlement, enhance reproduction success, or catch prey. Conversely, the role of spicules and skeletons in deterring predation has not been demonstrated. Knowledge of several aspects is still based on a single or a few species and extrapolations should be made only with caution. With the advent of new molecular techniques, new lines of research are presently open and active in this field.

Animals↗

Origin of tonic electrical activity patterns in the diaphragm of the fetal lamb.

The respiratory pattern generator in fetal and postnatal life activates the phrenic nucleus and diaphragm muscle with phasic bursts of activity. In the fetus, diaphragmatic activity is also characterized by tonic activity patterns of unknown origin. We have examined whether such activity is diaphragmatic, or radiated from nearby ribcage muscles, by placing two sets of electrodes side-by-side in the costal portion of the diaphragm in five fetuses. The rationale for this approach is that if tonic activity, radiates to the diaphragm it should be recorded by both sets of electrodes and there should be no delay between the action potentials from each set of electrodes. Of 24 single tonic units identified, 15 were recorded from only one of the two sets of electrodes in the diaphragm. In the 9 tonic units recorded from both sets of electrodes, there was a time delay between the appearance of the action potentials in the two recordings (mean +/- S.E.M. 1.6 +/- 0.2 ms). This is the expected conduction delay along the muscle fibres separating the two electrodes. Since tonic diaphragmatic activity persisted in fetuses with the spinal cord transected rostral or caudal to the phrenic nucleus, we conclude that the spinal cord alone is sufficient to produce the tonic activity recorded from the fetal diaphragm but that the brain may also generate such activity.

Animals↗

The segment polarity gene costal-2 in Drosophila. II. The origin of imaginal pattern duplications.

Imaginal pattern duplications caused by hypomorphic expression of the segment polarity gene costal-2 are described. These affect the anteroposterior coordinate of the imaginal disc. A very small part of the pattern is deleted and a large number of additional pattern elements arise in a progressive order, anterior-most first followed by more and more posterior structures. Mosaic analyses show that the duplications arise nonautonomously in the larval stages but that the costal-2 gene is not required after early embryogenesis. Arguments that the duplications are the result of cell interactions and intercalary growth that themselves arise from an abnormal polarity of the embryonic segment are presented.

Abdomen↗

Origins of motility patterns in isolated arterially perfused rat intestine.

BACKGROUND/AIMS: Assessment of the neuromuscular control of small intestinal motility and movement of luminal contents is hampered in vivo by measurement techniques and in vitro by tissue viability. The aim of this study was to establish the structural and functional integrity of an isolated segment of rat ileum and characterize its motility. METHODS: Segments of rat ileum were perfused arterially with oxygenated fluorocarbon and luminally with saline. Oral and aboral pressures were correlated with conformational changes detected by concurrent video imaging. RESULTS: Light and electron microscopy showed no neuromuscular abnormalities after experiments, and acetylcholine-induced pressure amplitudes were unchanged during experiments. Under basal conditions, low-frequency contractions showing constant frequency (0.27/min) and amplitudes (oral, 17 hPa; aboral, 15 hPa) corresponded to luminally occlusive aborally propagated contractions, which were eliminated by tetrodotoxin. High-frequency contractions with a constant frequency (27/min) were also seen; their basal amplitude (0.3 hPa) increased immediately before and after low-frequency contractions and after tetrodotoxin. Tetrodotoxin also increased basal intestinal tone. CONCLUSIONS: An isolated, arterially perfused segment of rat ileum retains structural and functional integrity. It shows low-frequency propulsive contractions, controlled by the enteric nervous system, and myogenic high-frequency contractions, probably subject to tonic neural inhibition.

Acetylcholine↗