Standard setting: a joint venture.
Explore the source record for details and available documents.
Child↗
Biomedical subjects
E Lawrence
Publications and source records attributed to E Lawrence.
Three secretory phospholipase A(2) genes that map to human chromosome 1P35-36 are not mutated in individuals with attenuated adenomatous polyposis coli.
Mutation of Pla2g2a, a secretory phospholipase A(2) gene, dramatically increases the number of intestinal polyps that develop in the multiple intestinal neoplasia (Min) mouse, a murine model for adenomatous polyposis coli in humans. We tested the hypothesis that mutation of the human homologue(s) of this gene might be responsible for the more severe phenotype (hundreds of polyps) seen in a subset of individuals with attenuated adenomatous polyposis coli (AAPC). DNA sequence analysis demonstrated that alterations of PLA2G2A, as well as related genes PLA2G2C and PLA2G5, were evenly distributed between three classes of AAPC subjects: those with small, intermediate, and large numbers of adenomatous colonic polyps. Among 67 additional unrelated AAPC subjects, a stop mutation in PLA2G2C did not correlate with an increased burden of adenomatous polyps. Therefore, mutation of the human homologue(s) of murine Pla2g2a does not appear to be responsible for phenotypic variation among subjects with AAPC.
Adenomatous Polyposis Coli↗
Polymorphonuclear leukocyte (PMN) migration in streptococcal pneumonia: comparison of older PMN with those recently released from the marrow.
In acute bacterial pneumonia, polymorphonuclear leukocytes (PMN) sequester in the lung and migrate into the alveolar airspaces. These local events are accompanied by a systemic response that includes release of PMN from the bone marrow into the circulation. The present study was designed to compare the sequestration and migration of these newly released PMN with those already in the circulation in a model of acute streptococcal pneumonia in rabbits. PMN were labeled in the mitotic pool in the marrow by administration of 5'-bromo-2'-deoxyuridine (BrdU 100 mg/kg) and the labeled cells were detected in blood and tissues by immunohistochemistry. The proportion of BrdU-labeled PMN (PMN BrdU) that sequestered and migrated in the lung tissue infected with Streptococcus pneumoniae and the uninfected lung was measured using morphometric techniques. The results show an increase in the proportion of PMN BrdU (6.0 +/- 1.0% to 17.3 +/- 3.8%, P<0.05) in the circulation 5 h following the induction of a pneumonia and the PMN expressed a higher concentration of L-selectin (9.3 +/- 0.7 to 14.9 +/- 0.8 MFI, P<0.05). The proportion of PMN BrdU in the control tissue was not different from the proportion in the systemic circulation (11.4 +/- 1.6%). The PMN BrdU increased in the pneumonic site at 5 h (19.9 +/- 3.4%, P<0.05) and 8 h (26.6 +/- 1.5%, P<0.05) after treatment. Only 2.8 +/- 0.3% and 2.8 +/- 0.6% of the PMN that migrated into the airspace at 5 and 8 h were PMN BrdU. We conclude that PMN released into the circulation as part of the systemic response to a local streptococcal pneumonia sequester normally but may be slow to migrate into the airspaces at the inflammatory site.
Animals↗
Luteinizing hormone-releasing hormone agonist inhibits cyclophosphamide-induced ovarian follicular depletion in rhesus monkeys.
Several investigators have demonstrated that LHRH agonists (LHRHa) inhibit ovarian follicular depletion induced by chemotherapeutic agents in rodents. It is not clear whether or not the same effects occur in primates. Six adult female rhesus monkeys underwent unilateral ovariectomy and were divided into two groups that received monthly injections of either Lupron depot (LHRHa) or placebo vehicle. Both groups received cyclophosphamide (CTX) injections. Weekly blood samples were assayed for FSH, estradiol and progesterone. Mean serum FSH levels significantly increased in the CTX group and significantly decreased in the LHRHa+CTX group. At the end of treatment, the remaining ovary was removed and serially sectioned, and ovarian follicle number and size were analyzed. CTX resulted in a significant reduction of nonprimordial follicles < 50 microns in diameter. The rate of loss of primordial follicles was expressed as a percentage of the original follicle count. During the treatment period, 64.6 +/- 2.8% of the total primordial follicles were lost in the CTX group compared to only 28.9 +/- 9.1% in the LHRHa+CTX group (p < 0.05). The percentage rate of decline per day was 0.120 +/- 0.012 for the CTX group compared to 0.057 +/- 0.019 (p < 0.05) for the LHRHa+CTX group. The findings indicate that LHRHa can protect the ovary against CTX-induced damage in rhesus monkeys.
Animals↗
Evidence for ETA and ETB receptors in rat skin and an investigation of their function in the cutaneous microvasculature.
1. The relative contribution of ETA and ETB receptors in the response of rat skin to endothelins was investigated by use of the selective ETB agonist IRL-1620 and the selective ETA antagonist BQ-123. 2. Binding data suggest the presence of ETA and ETB receptors as preincubation with [Ala3,11,18Nle7]-endothelin-1 reduced ET-1 binding by approximately 40%. 3. Intradermal injection of endothelin-1 (ET-1, 1-10 pmol/site) and ET-3 (3-100 pmol/site) induced a dose-dependent decrease in local blood flow assessed by 133Xe clearance at test sites in rat skin. 4. The endothelin analogue [Ala3,11,18Nle7]-ET-1 (30-1000 pmol/site) induced significant vasoconstriction (P < 0.05) at the highest doses used and the selective ETB receptor agonist, IRL-1620 [Suc[Glu9,Ala11,15] endothelin (8-21)], (0.01-100 pmol/site) acted in a potent manner to induce a significant (P < 0.01) dose-dependent decrease in 133Xe clearance. 5. Co-injection with the selective ETA receptor antagonist, BQ-123 (1 nmol/site), completely abolished the vasoconstriction to ET-1 and partially to ET-3, but had no effect on IRL-1620-induced vasoconstriction. In addition, IRL-1620 responses were not altered at sites treated with submaximal doses of a nitric oxide synthase inhibitor or a prostaglandin synthase inhibitor. 6. ET-1 and IRL-1620 (100 fmol-1 pmol/site) did not induce oedema formation as measured by [125I]-albumin accumulation in the presence or absence of the vasodilator, calcitonin gene-related peptide (CGRP). ET-1 (1-3 pmol/site) inhibited substance P-induced oedema formation and this effect,suggested to be secondary to a vasoconstrictor effect, was significantly reversed by BQ-123 (1 nmol/site).7. The findings in this study indicate that there are ETA and ETB receptors in rat skin and agents which activate either receptor act to mediate a decrease in cutaneous blood flow, but have no effect on increased microvascular permeability.
Animals↗
A strategy for constructing high-resolution genetic maps of the human genome: a genetic map of chromosome 17p, ordered with meiotic breakpoint-mapping panels.
Genetic linkage analyses with genotypic data obtained from four CEPH reference families initially assigned 24 new PCR-based markers to chromosome 17 and located the markers at specific intervals of an existing genetic map of chromosome 17p. Each marker was additionally genotyped with an ordered set of obligate, phase-known recombinant chromosomes. The breakpoint-mapping panels for each family consisted of two parents, one sib with a nonrecombinant chromosome, and one or more sibs with obligate recombinant chromosomes. The relative order of markers was determined by sorting segregation patterns of new markers and ordered anchor markers and by minimizing double-recombination events. Consistency of segregation patterns with multiple flanking loci constituted support for order. A genetic map of chromosome 17p was completed with 39 markers in 23 clusters, with an average space of 3 cM between clusters. The collection of informative genotypes was highly efficient, requiring fivefold fewer genotypes than would be collected with all the CEPH families. Given the availability of large numbers of highly informative PCR-based markers, meiotic breakpoint mapping should facilitate construction of a human genomic map with 1-cM resolution.
Base Sequence↗
Effect of BQ-123 and Ro 47-0203 (bosentan) on endothelin-induced vasoconstriction in the rat skin.
The effectiveness of intradermal (i.d.) BQ-123 (cyclo[D-Asp-Pro-D-Val-Leu-D-Trp]) and i.d. Ro 47-0203 (bosentan, 4-tert-butyl-N-[6-(2-hydroxy-ethoxy)-5-(2-methoxy-phenoxy)-2,2'-bipyr imidin-4 - yl]-benzene-sulfonamide) has been evaluated on local microvascular responses to endothelin-1 and endothelin-3, measured by a multiple site 133Xe clearance technique in rat skin in vivo. Intradermal injection of endothelin-1 (0.3 pmol/site) and endothelin-3 (10 pmol/site) induced a similar (approximately 50-60%) decrease in basal blood flow in rat skin. BQ-123 (3-1000 pmol/site), a selective endothelin ETA receptor antagonist, caused a significant dose-dependent decrease in the vasoconstriction induced by endothelin-1 (P < 0.05) but was less effective on vasoconstriction induced by endothelin-3. Bosentan (3-1000 pmol/site), a new non-peptide mixed antagonist of endothelin ETA and endothelin ETB receptors, significantly reduced the vasoconstriction induced by endothelin-1 but was less effective than BQ-123. BQ-123 and bosentan were similarly effective as antagonists of endothelin-3. BQ-123 and bosentan had no effect on basal blood flow and no inhibitory activity on vasoconstriction induced by vasopressin (0.03 pmol/site) or phenylephrine (300 pmol/site). These findings indicate that BQ-123 and bosentan are effective and selective inhibitors of the vasoconstriction induced by endothelins in the rat skin microvasculature.
Animals↗
Physical and genetic mapping of human chromosome 3 loci containing microsatellite repeats.
One hundred and six microsatellite repeat-containing loci, including 59 CA-containing repeats from the CEPH/Genethon collection, were regionally assigned on human chromosome 3 using a somatic cell hybrid mapping panel, diving the chromosome into 14 intervals. The others were dinucleotide and tetranucleotide repeat-containing loci newly developed for human chromosome 3, of which 26 were also localized by means of genetic linkage analysis against selected CEPH microsatellites. The regional assignment of these two marker sets in a common mapping panel facilitates their integration. Incorporation of these highly polymorphic loci into the developing physical and genetic maps should provide useful information for studies of various diseases involving chromosome 3.
Base Sequence↗
Genetic mapping of the BRCA1 region on chromosome 17q21.
Chromosome 17q21 harbors a gene (BRCA1) associated with a hereditary form of breast cancer. As a step toward identification of this gene itself we developed a number of simple-sequence-repeat (SSR) markers for chromosome 17 and constructed a high-resolution genetic map of a 40-cM region around 17q21. As part of this effort we captured genotypes from five of the markers by using an ABI sequencing instrument and stored them in a locally developed database, as a step toward automated genotyping. In addition, YACs that physically link some of the SSR markers were identified. The results provided by this study should facilitate physical mapping of the BRCA1 region and isolation of the BRCA1 gene.
Base Sequence↗
A radiation hybrid map of the BRCA1 region.
A locus on chromosome 17q, designated "BRCA1," has been identified as a predisposition gene for breast cancer. A panel of chromosome 17-specific radiation-reduced somatic cell hybrid clones has been assembled for high-resolution mapping of chromosome 17. A series of 35 markers, known to span the BRCA1 locus, were tested against this hybrid panel by PCR assays. Statistical analysis of these data yields a BRCA1 radiation hybrid map at a density sufficient to initiate YAC cloning and pulsed-field gel electrophoretic mapping of the candidate region. In addition, many of the markers reveal genetic polymorphisms and may be tested in breast cancer families and in loss-of-heterozygosity studies of sporadic breast cancers to better define the BRCA1 gene candidate region.
Animals↗
Big endothelin-1 and big endothelin-3 are constrictor agents in the microvasculature: evidence for the local phosphoramidon-sensitive conversion of big endothelin-1.
The effect of local administration of big endothelin-1 (1-38, big ET-1) has been investigated on blood flow in the skin of anaesthetised rats, measured by 133Xe clearance. The local effects of big ET-1 and big endothelin-3 (1-41, big ET-3) have also been determined on microvessel diameter by intravital microscopy of the cheek pouch of anaesthetised hamsters. Big ET-1 (i.d.) caused a dose-dependent decrease in skin blood flow and was 10 times less potent than endothelin-1 (ET-1). Phosphoramidon (30 nmol/site i.d.) did not effect blood flow but when coinjected selectively attenuated the effect of big ET-1 (1 and 3 pmol/site, P < 0.05). In the cheek pouch big ET-1 (100 pmol) induced an intense and long-lasting arteriolar constriction. Phosphoramidon (100 nmol) abolished constriction to big ET-1 (100 pmol) but not to ET-1 (10 pmol). The modest constriction induced by big ET-3 (300 pmol) was not inhibited by phosphoramidon (100 nmol). Results suggest that a phosphoramidon-sensitive endothelin-converting enzyme situated close to microvascular vessels is important in the conversion of big ET-1. The mechanism for activity of big ET-3 in the microcirculation is unclear.
Animals↗
Polymorphic SSR (simple-sequence-repeat) markers for chromosome 20.
Chromosome 20-specific simple-sequence-repeat (SSR) markers were developed from a flow-sorted phage library (LL20NS01), subcloned in Bluescript, and screened with a tetranucleotide repeat, (AAAG)6, to identify potentially polymorphic loci. Of 100 clones sequenced, 39 were selected to construct primers. Of these 39, 22 were polymorphic. Reference to the CEPH linkage database (version 5) permitted genetic mapping of 16 of the new markers to specific regions of chromosome 20. Ten of the SSRs showed heterozygosity indices (above 70%) that would qualify them as potential index markers.
Base Sequence↗
Isolation of 1001 new markers from human chromosome 11, excluding the region of 11p13-p15.5, and their sublocalization by a new series of radiation-reduced somatic cell hybrids.
The determination of the physical map of human chromosome 11 will require more clones than are currently available. We have isolated an additional 1001 new markers in a bacteriophage vector from a somatic cell hybrid cell line that contains most of chromosome 11, except the middle of the short arm. These markers were localized to five different regions, 11p15-pter, 11p12-cen, 11q11-q14, 11q14-q23, and 11q23-qter, by a panel of previously characterized somatic cell hybrids. The region 11q11-14 harbors genes that have been shown to be important in breast cancer, B-cell lymphomas, centrocytic lymphomas, asthma, and multiple endocrine neoplasia, type 1 (MEN1). To determine the positions of the recombinant clones located there, we developed a new series of radiation-reduced somatic cell hybrids. These hybrids, together with those previously characterized, allowed us to map the 11q11-q14 markers into 11 separate segregation groups.
Asthma↗
Responses to endothelins in the rat cutaneous microvasculature: a modulatory role of locally-produced nitric oxide.
1. The response of the cutaneous microvasculature to intradermal injection of the endothelins (ET-1, ET-2 and ET-3) and the modulatory effect of endogenously produced nitric oxide (NO) have been determined in the rat. 2. Intradermal injection of endothelins (0.1- 10 pmol/site) induced dose-dependent local reductions in blood flow, measured by 133xenon clearance, with the following potency order; ET-1 = ET-2 greater than ET-3. 3. Laser Doppler blood flowmetry established that ET-1 (10 pmol/site) significantly (P less than 0.05) reduced microvascular blood flow for 3 h after injection. Over a wide dose-range, the response to the endothelins did not include any vasodilatation or visible flare. 4. A possible modulatory role of locally-produced NO was investigated by the intradermal injection of the potent inhibitor of NO generation NG-nitro-L-arginine methyl ester (L-NAME). L-NAME (100 nmol/site) injected alone induced a significant decrease in blood flow. The vasoconstriction induced by L-NAME was partially reversed by L-arginine (P less than 0.05) but not observed with NG-nitro-D-arginine methyl ester (D-NAME). 5. L-NAME significantly (P less than 0.05) enhanced the decrease in blood flow induced by submaximal doses of ET-1, ET-2 and ET-3 and vasopressin, although the results do not suggest that any of the vasoconstrictors stimulate NO release. The response to L-NAME was still observed 3.5 h after inducing a prolonged constriction with ET-1 (10 pmol/site).6. These results indicate that locally produced NO maintains a dilator tone in the cutaneous microvasculature of the rat and acts to modulate the effect of vasoconstrictors such as endothelins. Hence, it is suggested that in conditions where endogenous NO release is reduced, vasoconstrictor agents such as the endothelins could induce a dangerous decrease in blood flow possibly leading to ischaemia and tissue necrosis.
Animals↗
Altered microvascular reactivity to endothelin-1, endothelin-3 and NG-nitro-L-arginine methyl ester in streptozotocin-induced diabetes mellitus.
1 We have determined the dermal microvascular effects of the nitric oxide (NO) synthase inhibitor, NG-nitro-L-arginine methyl ester (L-NAME, 100 nmol/site), endothelin-1 (ET-1, 0.1-10 pmol/site) and ET-3 (0.1-30 pmol/site) in rats with streptozotocin (STZ)-induced diabetes mellitus. Cutaneous blood flow changes as measured by a 133xenon (133Xe) clearance technique, were determined in diabetic rats four weeks after treatment with streptozotocin (STZ) and compared with responses measured in normal rats four weeks after treatment with saline. 2 Resting skin blood flow was similar in diabetic and in normal rats, as measured by 133Xe clearance and laser Doppler flowmetry. 3 Intradermal NG-nitro-L-arginine methyl ester (L-NAME) reduced skin blood flow in normal rats by 55.2 +/- 2.6% as measured by 133Xe clearance, (n = 9). L-NAME was significantly less effective in diabetic rats, inducing a 40.9 +/- 7.7% decrease in blood flow (n = 9, P less than 0.05). The enantiomer D-NAME had no effect in either group of rats. 4 Low doses of ET-1 and ET-3 injected intradermally induced dose-dependent decreases in blood flow, measured by 133Xe clearance, which were similar in both groups of rats. However, the responses to the highest doses of ET-1 (10 pmol/site) and ET-3 (10 and 30 pmol/site) were significantly reduced in the diabetic compared with the normal rats (P less than 0.05).In addition vasoconstriction to the highest doses of vasopressin (0.3 and 3 pmol/site) and vasodilatation to the neuropeptide calcitonin gene-related peptide (CGRP, 1O pmol/site) were similarly reduced in the diabetic rats (P <0.05).5. The decrease in blood flow induced by submaximal doses of ET-1 was enhanced by co-injection with L-NAME (100 nmol/site) in both diabetic and normal rats. However, this enhanced response was significantly reduced in the diabetic rats (P<0.05). A similar pattern of responses were observed to ET-3 in the presence and absence of L-NAME.6. These results indicate that the cutaneous microvasculature of rats with STZ-induced diabetes responds differently to intradermal ET-1 and ET-3 compared with normal rats; a similarly altered vascular reactivity was observed with vasopressin and CGRP. Hence, the diabetic microcirculation has impaired responses to several vasoconstrictors and a vasodilator. The effect of the nitric oxide synthase inhibitor L-NAME is also suppressed in the diabetics, suggesting that there may be decreased local production of, or response, to nitric oxide.
Animals↗
Electronic imaging in a teaching hospital intensive care unit: evaluation of the clinical review system.
An intrahospital image-communication and display system was installed and is in continuous use. All images obtained in the medical intensive care unit (MICU) are digitized in the radiology department, then transmitted, stored and retrieved at the nurses' station in the MICU. This unit was easy to install, required minimal user training, and has been in continuous use for 1 year with negligible down time. The details of this system are provided in this report.
Computer Communication Networks↗
The influence of cephalostatic ear rods on the positions of the head and neck during postural recordings.
This study examined the effect of cephalostatic ear rods on the positions of the head and neck. The method error was assessed for postural recordings of the head and neck position made with and without ear rods. A photographic angle was correlated with the postural angles on x-ray film. The material compared 33 dental students who were recorded with ear rods in and with ear rods out. Subjects were chosen randomly to repeat the postural recordings. The differences between the mean for each postural variable were subjected to comparative analysis, using Student's t test for paired samples. A significant difference (p less than or equal to 0.05) was found between the means of the inclination of the cervical spine to the true horizontal and the means of the photographic angle. The mean values for the remaining postural variables showed an insignificant but consistent pattern of axial extension of the cervical spine. Cephalostatic ear rods may alter head and neck position during postural recordings. The method error made for recording total head and neck position with ear rods was higher than without ear rods. The difference in the photographic angle was found to have a moderate positive correlation with the difference in the cervical inclination and the total head and neck position. These data suggest that lateral cephalostatics without ear rods may be used to record total head and neck position and the photographic technique may be used as a quick, inexpensive method for the clinician to determine head and neck positional changes before and after treatment.
Adult↗
A comparison of acetaminophen and rimantadine in the treatment of influenza A infection in children.
Rimantadine was compared with acetaminophen in a double-blind randomly assigned therapeutic trial in 63 children presenting with influenzal symptoms. Forty-nine of the children were proven to have influenza A by culture on presentation. Forty-three of the cultures, 88%, were influenza A/H1N1 strains. Both drugs were well tolerated. Rimantadine lowered the amount of virus shed in the first 2 days after initiation of therapy. Clinical resolution of illness was not different between the two therapeutic modalities. In individuals who shed virus for 4 days, strains recovered on the last day were relatively resistant to rimantadine.
Acetaminophen↗