Number In Relation Research Articles

EGF-r gene copy number changes in renal cell carcinoma detected by fluorescence in situ hybridization.

Expression of epidermal growth factor receptor (EGF-r) is a frequent event in renal cell carcinoma (RCC). To investigate the role of EGF-r gene copy number changes related to EGF-r overexpression, 50 RCC specimens were examined by fluorescence in situ hybridization (FISH) and immunohistochemistry. Dual-labelling FISH with a repetitive pericentromeric probe for chromosome 7 and a probe for the EGF-r gene (at 7p13) was performed to analyse the EGF-r copy number in relation to chromosome 7 copy number on a cell-by-cell basis. Polysomy 7 was frequent in all histological types of RCC. Chromosome 7 polysomy was found in 26 of 35 clear cell (74 per cent), nine of nine papillary, and three of three chromophobe RCCs. EGF-r gene copy number was closely associated with the chromosome 7 copy number on a cell-by-cell basis. No EGF-r gene amplifications were found. EGF-r positivity was found in 37 of 50 cases (74 per cent) by immunohistochemistry. EGF-r positivity was more common in clear cell (81 per cent) than in papillary tumours (40 per cent; P = 0.029). Neither chromosome 7 nor EGF-r gene copy number was associated with EGF-r expression, indicating that an increased gene dosage is not a mechanism of EGF-r overexpression in RCC.

EGF‐r gene copy number changes in renal cell carcinoma detected by fluorescence in situ hybridization

Expression of epidermal growth factor receptor (EGF-r) is a frequent event in renal cell carcinoma (RCC). To investigate the role of EGF-r gene copy number changes related to EGF-r overexpression, 50 RCC specimens were examined by fluorescence in situ hybridization (FISH) and immunohistochemistry. Dual-labelling FISH with a repetitive pericentromeric probe for chromosome 7 and a probe for the EGF-r gene (at 7p13) was performed to analyse the EGF-r copy number in relation to chromosome 7 copy number on a cell-by-cell basis. Polysomy 7 was frequent in all histological types of RCC. Chromosome 7 polysomy was found in 26 of 35 clear cell (74 per cent), nine of nine papillary, and three of three chromophobe RCCs. EGF-r gene copy number was closely associated with the chromosome 7 copy number on a cell-by-cell basis. No EGF-r gene amplifications were found. EGF-r positivity was found in 37 of 50 cases (74 per cent) by immunohistochemistry. EGF-r positivity was more common in clear cell (81 per cent) than in papillary tumours (40 per cent; P=0·029). Neither chromosome 7 nor EGF-r gene copy number was associated with EGF-r expression, indicating that an increased gene dosage is not a mechanism of EGF-r overexpression in RCC. © 1998 John Wiley & Sons, Ltd.

Some quantitative aspects of natural babesial infection in the haemolymph of Boophilus microplus engorged female ticks.

Quantitative aspects of the natural babesial (Babesia bovis and Babesia bigemina) infection in Boophilus microplus engorged female ticks obtained from two herds of Holstein heifers positive by the immunofluorescent antibody test to both protozoan were evaluated. The number of kinetes/microscope field of haemolymph was determined for each tick from day 5 to 10 post-collection. A close relationship between daily and cumulative babesial infection was detected. Correlation and determination coefficients between days post-collection and the daily and cumulative infection rates, including heavily infected ticks (those ticks carrying at least 3.0 kinetes/microscope field of haemolymph), were always higher than 0.9 (P < 0.01) in ticks of both herds. The median was found to be a more representative measure than the mean to define the distribution of kinetes number amongst infected ticks since this is a negative binomial distribution. The analysis of the sequential order of days of infection more accurately showed the amplification of the babesial infection in the tick haemolymph than the evolution of kinetes number in relation to days post-collection. Sampling ticks on days 8, 9 and 10 post-collection would have detected all ticks infected with Babesia spp. from both herds. A categorization of infected or non infected ticks would be of greater epidemiological importance than the haemolymph infection level, based upon previous laboratory studies that showed a poor relationship between haemolymph infection in the female ticks and the infection rate in their eggs. However, further studies in natural infected ticks and better techniques to differentiate B. bovis and B. bigemina kinetes are needed before these laboratory results can be applied to field conditions.

Number and size of epineurial blood vessels in normal and diseased human sural nerves

The number and dimensions of epineurial blood vessels in normal human sural nerves have, thus far, not been determined using systematic, reproducible morphometric methods, although this nerve is most frequently used for diagnostic biopsies. Quantitative changes in epineurial blood vessels appear to be major parameters for identifying angiopathy and angiopathic peripheral neuropathy. Therefore, we examined the epineurial blood-vessel number in relation to the age of the patients and to the number and size of the nerve fascicles in each of 51 human sural nerve biopsies. The data from a control group were compared with pathological cases. We found that the number of epineurial blood vessels (normal mean: 57. 7) increased significantly (up to 196) in biopsies where there were signs of angiopathy (P</=0.01) or vasculitis (P</=0.05). The increase in the number of epineurial blood vessels usually resulted from a proliferation of capillaries. The fascicular cross-sectional area did not appear to be related to the number of epineurial blood vessels, although it increased significantly in cases with vasculitis (P</=0.05) or an axonal type of neuropathy (P</=0.05). Thus, this study shows that the number of epineurial blood vessels is a helpful parameter in verifying angiopathy and angiopathic peripheral neuropathy.

Frequent homozygous deletion of cyclin-dependent kinase inhibitor 2 (MTS1, p16) in superficial bladder cancer detected by fluorescence in situ hybridization

Deletion of all or part of chromosome 9 is a well-described genetic alteration in bladder tumors. It has been proposed that inactivation of a tumor-suppressor gene on chromosome 9 is an important event in tumor development. Recent reports have supported cyclin-dependent kinase inhibitor 2 (CDKN2, also known as MTS1, INK4, p16) at 9p21 as a candidate tumor-suppressor gene in solid tumors. However, the prevalence of CDKN2 mutations in primary bladder tumors has been controversial. Therefore, we applied gene-specific probes for CDKN2 and the interferon alpha gene (IFNA), also located at 9p21, to characterize further the genomic deletions at this locus in bladder cancer. Seventeen superficial (pTa or pT1) bladder tumor specimens were examined for gene deletion by fluorescence in situ hybridization. Dual-labeling hybridization with a repetitive pericentromeric probe for chromosome 9 and a gene-specific probe for CDKN2 was performed to characterize the gene copy number in relation to the chromosome 9 copy number on a cell-by-cell basis. Homozygous deletion for CDKN2 without homozygous IFNA deletion was found in 5 of 17 tumors tested. Both genes were deleted in one additional case, and one tumor showed deletion of IFNA without deletion of CDKN2. Homozygous deletion at the 9p21 locus was found only in tumors having monosomy for the chromosome 9 centromeric signal. These results indicate that the homozygous deletion of the CDKN2 gene is a frequent and early event in superficial bladder cancer.

Frequent homozygous deletion of cyclin‐dependent kinase inhibitor 2 (MTS1, p16) in superficial bladder cancer detected by fluorescence in situ hybridization

Deletion of all or part of chromosome 9 is a well-described genetic alteration in bladder tumors. It has been proposed that inactivation of a tumor-suppressor gene on chromosome 9, is an important event in tumor development. Recent reports have supported cyclin-dependent kinase inhibitor 2 (CDKN2, also known as MTS1, INK4, p16) at 9p21 as a candidate tumor-suppressor gene in solid tumors. However, the prevalence of CDKN2 mutations in primary bladder tumors has been controversial. Therefore, we applied gene-specific probes for CDKN2 and the interferon alpha gene (IFNA), also located at 9p21, to characterize further the genomic deletions at this locus in bladder cancer. Seventeen superficial (pTa or pTI) bladder tumor specimens were examined for gene deletion by fluorescence in situ hybridization. Dual-labeling hybridization with a repetitive pericentromeric probe for chromosome 9 and a gene-specific probe for CDKN2 was performed to characterize the gene copy number in relation to the chromosome 9 copy number on a cell-by-cell basis. Homozygous deletion for CDKN2 without homozygous IFNA deletion was found in 5 of 17 tumors tested. Both genes were deleted in one additional case, and one tumor showed deletion of IFNA without deletion of CDKN2. Homozygous deletion at the 9p21 locus was found only in tumors having monosomy for the chromosome 9 centromeric signal. These results indicate that the homozygous deletion of the CDKN2 gene is a frequent and early event in superficial bladder cancer. Genes Chromosom. Cancer 19:84–89, 1997. © 1997 Wiley-Liss, Inc.

Growth and multiplication of white skeletal muscle fibres in carp larvae in relation to somatic growth rate

A morphometric analysis of white axial muscle of common carp Cyprinus carpio was undertaken in order to quantify increase in fibre size, fibre nuclei and fibre number in relation to somatic growth rate during early life. In fast‐growing carp larvae fed zooplankton, length and height of fibres from the central part of dorsolateral muscle increased at the same rate (0.75) relative to the total length of the larvae during the first 2 weeks of feeding. During this period, the number of nuclei per fibre increased threefold while the number of nuclei per unit fibre surface remained constant. In fast‐growing larvae fed a formulated diet, the total cross‐sectional area of one epaxial quadrant of white muscle and the total area of white fibres increased at almost the same rate (3.15; 3.23) relative to larval total length during the first 28 days of exogenous feeding. The total number of white fibres increased faster (2.07) relative to the total length of larvae than the mean area of white fibres (1.16). Hyperplasia accounted for 64% of muscle growth in these larvae. The proportion of fibres with a width &lt; 10 μm decreased from 72% at first feeding to 14% 28 days later, while the proportion of fibres with a width &gt;20 μm which was 0% at first feeding increased up to 34% in the same time. The recruitment of new white fibres seemed to be almost the same in the whole muscle quadrant at first feeding and 18 or 28 days later but, 8 days after first feeding, a transient significant recruitment of new fibres was shown at the apex of the myotome. Comparisons between fast‐ and slow‐growing groups of larvae showed that for a given larval total length: (1) the mean width of central white fibres was higher and the proportion of central fibres with a width &lt;10 μm was lower in slow‐growing larvae than in fast‐growing ones; (2) the total number of white fibres was lower for a higher total cross‐sectional area of white muscle in slow‐growing larvae than in fast‐growing ones. These results suggest that, in Cyprinus carpio larvae, slow‐growing conditions are related to a decreased contribution of hyperplasia to muscle growth.

Variations in sperm number in relation to larval crowding and spermatophore size in the armyworm, Pseudaletia separata

1. Number of sperm and its relationship with larval rearing density were investigated in the armyworm Pseudaletia separata. Males that emerged from crowded larvae produced significantly more apyrene sperm than those from solitary larvae (375 700 ± 116 600 and 290 300 ± 99 600 at a mating with a 3‐day old virgin, respectively), with no significant difference in number of eupyrene sperm between the two types being observed.2. For both solitary‐ and crowded‐type, the amount of fertile sperm the males produced at a mating exceeded the number needed to fertilize all of a female’s eggs, suggesting that sperm competition may be a major selective force for keeping sperm numerous. The production of more apyrene sperm by crowded‐type males may be an adaptation to cope with the increased sperm competition from rival males at high density.3. The relationship between number of sperm and spermatophore size was also studied using solitary‐type moths. Large spermatophores were found to have more eupyrene and apyrene sperm than small ones.

Performance evaluation of a finite buffer generalized selective repeat ARQ scheme for satellite communications

This article presents a new generalized selective repeat automatic repeat request (ARQ) scheme for error control in broadcast and point-to-point satellite communication systems. In the proposed scheme, each bit in a packet is repeated m times consecutively to increase the transmission reliability. Finite capacity buffers have been assumed at the earth stations. The throughput, theoretically derived for the proposed scheme, is optimized with respect to the number of copies transmitted per bit. A suitable algorithm to adaptively choose this number in relation to the transmission channel propagation conditions can also be used. In comparison with classical and modified versions of the selective repeat ARQ scheme as described in the literature, the proposed scheme provides enhanced throughput, especially with poor channel conditions and a high number of receiving earth stations.

Maintenance of transposable element copy number in natural populations of Drosophila melanogaster and D. simulans.

To investigate the main forces controlling the containment of transposable elements (TE) in natural populations, we analyzed the copia, mdg1, and 412 elements in various populations of Drosophila melanogaster and D. simulans. A lower proportion of insertion sites on the X chromosome in comparison with the autosomes suggests that selection against the detrimental effects of TE insertions is the major force containing TE copies in populations of Drosophila. This selection effect hypothesis is strengthened by the absence of the negative correlation between recombinaiton rate and TE copy number along the chromosomes, which was expected under the alternative ectopic exchange model (selection against the deleterious rearrangements promoted by recombination between TE insertions). A cline in 412 copy number in relation to latitude was observed among the natural populations of D. simulans, with very high numbers existing in some local populations (around 60 copies in a sample from Canberra, Australia). An apparent absence of selection effects in this Canberra sample and a value of transposition rate equal to 1-2 x 10(-3) whatever the population and its copy number agree with the idea of recent but temporarily drastic TE movements in local populations. The high values of transposition rate in D. simulans clearly disfavor the hypothesis that the low amount of transposable elements in this species could result from a low transposition rate.

Sexually dimorphic patterns of neural organization in the feeding appendages of fiddler crabs.

The organization of sensory nerves and sensilla was examined in the feeding claw of two species of fiddler crabs, Uca pugnax and U. pugilator, using neuroanatomical and behavioral techniques. Surveys of the populations of axons indicate that claws of adult crabs contain 25000-40000 neurons. Approximately 85% of the population consists of axons with diameters less than 1 microm, suggesting they may represent chemosensory neurons. Females show an enhanced population of these small (putative chemosensory) axons relative to males, providing a mechanism to explain previously observed sexual differences in behavioral chemosensitivity to feeding stimulants. Surveys of the claw surface show a variety of external structures that could contain either chemo- or mechanosensory receptor neurons. There are hair-like sensilla of several types, some of which are more abundant in females than in males. In addition, claws show previously undescribed pit sensilla reminiscent of known bimodal chemo- and mechanosensory sensilla found in certain decapod crustaceans. Morphological properties of hair-like sensilla, as well as their small number in relation to the large population of presumptive chemosensory axons, suggest that they have a limited role in chemosensation. Most of the chemosensory axons probably originate in the pit sensilla.

Male crickets increase sperm number in relation to competition and female size

There is evidence to suggest that males of various species can respond to the threat of sperm competition by varying the amount of sperm transferred during copulation. We tested this in two species of cricket, Acheta domesticus and Gryllodes supplicans (Orthoptera: Gryllidae) by varying the apparent threat of intermale competition experimentally. The results showed that males of both species increased the amount of sperm transferred as apparent competition increased and that male A. domesticus transferred more sperm when encountering larger females. The results also showed that male G. supplicans produced a larger spermatophylax when a larger ampulla was transferred, a relationship consistent with a sperm protection function.

Substructures in the core of thick filaments: Arrangement and number in relation to the paramyosin content of insect flight muscles

Transverse sections (100–140 nm thick) of solid myosin filaments of the flight muscles of the honeybee, Apis mellifica, the fleshfly, Phormia terrae-novae and the waterbug, Lethocerus uhleri, were photographed in a JEM-200 electron microscope at 200 kV. The images were digitized and computer processed by rotational filtering. The power spectra of the images of each of these filaments showed six-fold symmetry for the outer wall region and three-fold symmetry for the inner wall region. Images of the honeybee additionally showed three-fold symmetry for the center of the filament. Considering both paramyosin content of the myosin filaments and the results of the rotational filtering, we suggest the existence of 3 paramyosin strands in the myosin filaments of the fleshfly, 6 paramyosin strands in the honeybee filaments and 5 strands in the myosin filaments of the waterbug. In the case of the honeybee, the 3 paramyosin strands of the inner wall are positioned directly opposite the myosin subfilaments, while the 3 strands of the center seem to be arranged opposite the gaps between the myosin subfilaments. The paramyosin filaments of the fleshfly wobble between 2 myosin subfilaments, without loosing their three-fold symmetry arrangement in the inner wall. The 3 paramyosin strands in the inner wall of the waterbug myosin filaments are either arranged opposite the myosin subfilaments or opposite the gaps between the subfilaments. Finally, we were able to generate a 3-dimensional reconstruction of the myosin filament of the honeybee, showing the parallel arrangement of both, myosin subfilaments and paramyosin strands, relative to the long filament axis.

Quantitation of c-myc gene amplification by a competitive PCR assay system.

Gene amplification is a common event in the progression of human cancers. The detection and quantitation of certain amplified oncogenes has been shown to have prognostic importance in certain human malignancies. A method is described that utilizes the principles of competitive PCR for quantitation of the c-myc gene copy number in relation to the copy number of a reference gene (tissue plasminogen activator [t-PA] gene) located on the same chromosome (8) as the c-myc gene. This ratio gives the true level of amplification of the c-myc gene, accounting for variables such as cell number, cell cycle phase, and chromosome 8 ploidy. The determination of gene amplification depends on the precise measurement of the ratio of target and reference genes. An important feature of this assay is that the competitive reference standards used for target gene c-myc and reference gene t-PA have been linked to form a hybrid. This simple modification guarantees that both reference gene and target gene assay tubes get identical amounts of the competitive template for each gene, thereby eliminating a significant source of error. This method has the same desirable attributes of standard PCR in that very small sample sizes are required and that results can easily be obtained in < 24 hr. In addition, this technique does not require the use of radioactivity or expensive DNA detection kits, and thus, may give it wider applicability for the study of human cancers.

Glomerular number and size in relation to age, kidney weight, and body surface in normal man.

The number and size of glomeruli in normal, mature human kidneys were estimated by a direct and unbiased stereological method, the fractionator. The number was 617,000 on average, and the mean size 6.0 M microns3. Both glomerular number and size showed significant negative correlation to age and significant positive correlation to kidney weight. Apparently, humans loose glomeruli with age. Body surface area correlated positively to kidney weight and total glomerular volume but not to number of glomeruli. Body surface area correlates significantly with metabolic rate (Robertson and Reid, Lancet, 1: 940-943, 1952). Thus, intraspecies adaptation of kidney filtration capacity to the metabolic demand is performed by changing the size of glomeruli, i.e., the number of glomeruli in individuals of a given species is independent of the metabolic rate.

Hereditary hypotrophic axonopathy with neurofilament deficiency in a mutant strain of the Japanese quail

A primary axonal disease affecting the central and peripheral nervous system was discovered in a new mutant strain of the Japanese quail, named quiver (Quv). Quv showed significantly smaller cross-sectional areas of the cervical spinal cord and the optic and sciatic nerves, when compared with controls by light microscopic morphometry. In the cervical spinal cord, electron microscopic morphometry indicated that myelinated axons in Quv were significantly smaller in size than in controls, though greater in density. The axonal circularity was not significantly different from that of controls. Electron microscopically and immunohistochemically, neurofilaments were not detected in the axons or neuronal cell bodies. Axons in Quv were composed mainly of microtubules, which were increased in number in relation to the axonal size. From these findings, the lesions observed in Quv were regarded as axonal hypotrophy (growth arrest or retardation) due to altered neurofilament expression.

Centrosome and microtubule dynamics during meiotic progression in the mouse oocyte

The disposition, function and fate of centrosomes were analysed in mouse oocytes undergoing in vitro meiotic maturation, using multiple-label fluorescence microscopy. Oocytes fixed at various points during meiotic progression were double labeled with either human centrosome-specific antibody, 5051, and anti-tubulin antibodies or 5051 and MPM-2 antibodies in order to evaluate the microtubule nucleation capacity and phosphorylation status of centrosomes during this process. Double labeling with anti-tubulin antibodies revealed two populations of centrosomes that undergo stage-specific changes in number, location and microtubule nucleation capacity in relation to spindle assembly and cytoplasmic events. Specifically, one population was consistently associated with chromatin throughout meiotic maturation whereas a second population of cytoplasmic centrosomes exhibited maximal numbers and nucleation capacity at prometaphase and anaphase of meiosis-I. Quantitative evaluation of cytoplasmic centrosomes indicated increased numbers during the transition from diakinesis to prometaphase and metaphase to anaphase and total disappearance during telophase. Colocalization studies with MPM-2 revealed that centrosomes were always phosphorylated. However, at metaphase of meiosis I and II the microtubule nucleation capacity of centrosomes was diminished. These results suggest the existence of two discrete populations of centrosomes in the mouse oocyte that are coordinately regulated to subserve aspects of microtubule organization relative to both nuclear and cytoplasmic events.

Accidents in the institutionalized elderly: A risk analysis

Among a total of 4,862 admittances to a Swedish geriatric hospital and its associated nursing homes, 827 accidents occurred in 588 patients during one year. The purpose of the present study was to establish the direct causes of these accidents and to identify possible risk factors. Information was collected from medical records, interviews with patients and staff, examination of the mental and physical state of the patients, and through reconstruction of the accidents. The investigation embraced 270 patients with 308 major accidents (fractures, sprains, open wounds, concussions and injuries to ligaments), and 318 patients with 519 minor accidents (bruises, contusions, abrasions and minor burns). Injury-free patients with nearest lower bed number in relation to patients with major accidents formed a control group. Patients with previous injuries, balance disturbances, and polypharmacy were at high risk, and intrinsic factors such as dizziness and impaired balance proved to be more significant as direct causes for the occurrence of accidents than environmental factors. The estimated risk for a patient with all these risk factors to have an accident during one year was 94%.

Blood eosinophil number and activity in relation to lung function in patients with asthma and with eosinophilia

Blood eosinophil count, serum concentrations of eosinophil cationic protein (ECP), eosinophil protein X (EPX), myeloperoxidase (MPO), and peak expiratory flow (PEF) rate were studied in 23 patients with severe labile asthma characterized by eosinophilia at the start and end of a treatment period of 5 weeks. The mean blood eosinophil count was 808 × 10 6/L at the start of the treatment period. Serum ECP and EPX were significantly raised compared with that of the references, whereas the mean serum MPO level was normal. The mean PEF was significantly and negatively correlated to both blood eosinophil count and serum ECP and EPX, but the predominant correlation was that between blood eosinophil count and PEF. At the end of the treatment period, PEF had increased and the blood eosinophil count and serum ECP and EPX were reduced when these values were compared with the values at the start of the treatment period. There was a significant and negative correlation of mean PEF to serum ECP but not to the blood eosinophil count. In individual subjects, the decreases in the blood eosinophil counts and serum EPX were significantly correlated to the individual increases of mean PEF. In conclusion, the present investigation indicates that in patients with asthma and pronounced eosinophilia, the lung function of the patients was principally related to the number of circulating eosinophils, whereas, when their eosinophilia was reduced to moderate levels, the patient's lung function was closer related to the activity of the eosinophils.

Changes in size and number of spinal motoneurons in relation to growth of the musculature in the eel, Anguilla

Estimates of the numbers of spinal motoneurones in relation to growth in the eel, Anguilla, were made by counting the axons contained within the ventral roots. Motoneuronal size was determined as the surface area of cell somata labelled retrogradely from applications of tracer (horseradish peroxidase, cobalt lysine) to the musculature or spinal nerves. The sizes and numbers of muscle fibres from red and white portions of the myotomal musculature were determined from frozen sections. Measurements of motoneurone size and number in relation to the size and number of the muscle fibres were obtained from the same body region for eels of body lengths ranging from 65 to 930 mm and for 3 different stages of the eel's life history (glass, yellow and silver eels). The mean sizes and the numbers of red and white muscle fibres, and motoneuron size, increase substantially in relation to body length; the numbers of axons in the ventral roots of fish of different body lengths, however, are very similar (approx. 130 per half segment). Silver eels are indistinguishable from yellow eels of a similar size with respect to the size and number of motoneurone somata and axons and to the number of muscle fibres. In silver eels red muscle fibres are similar in size to those of yellow eels, but the white fibres are larger.