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Biomedical subjects

R Watson

Publications and source records attributed to R Watson.

At least 19 recordsLinked to original sources
PubMed1992

Reverse transcription with nested polymerase chain reaction shows expression of basic fibroblast growth factor transcripts in human granulosa and cumulus cells from in vitro fertilisation patients.

Basic fibroblast growth factor (bFGF) is a potent angiogenic factor that has also been implicated in granulosa cell and oocyte maturation. We now report the expression of messenger ribonucleic acid (mRNA) encoding bFGF in human granulosa and cumulus cells obtained at oocyte recovery in in vitro fertilisation patients. It was necessary to use the sensitive technique of a nested polymerase chain reaction (PCR) after reverse transcription (RT) to detect transcripts. This finding in conjunction with a recent report showing the presence of transcripts for transforming growth factor beta (TGF beta) in the same type of cells by PCR indicates that mechanisms are in place for controlling extracellular proteolysis and cell differentiation.

Base Sequence↗
PubMed1992

Overexpression of the dctA gene in Rhizobium meliloti: effect on transport of C4 dicarboxylates and symbiotic nitrogen fixation.

Symbiotic nitrogen fixation may be limited by the transport of C4 dicarboxylates into bacteroids in the nodule for use as a carbon and energy source. In an attempt to increase dicarboxylate transport, a plasmid was constructed in which the Rhizobium meliloti structural transport gene dctA was fused to a tryptophan operon promoter from Salmonella typhimurium, trpPO. This resulted in a functional dctA gene that was no longer under the control of the dctBD regulatory genes, but the recombinant plasmid was found to be unstable in R. meliloti. To stably integrate the trpPO-dctA fusion, it was recloned into pBR325 and recombined into the R. meliloti exo megaplasmid in the dctABD region. The resultant strain showed constitutive dctA-specific mRNA synthesis which was about 5-fold higher than that found in fully induced wild-type cells. Uptake assays showed that [14C]succinate transport by the trpPO-dctA fusion strain was constitutive, and the transport rate was the same as that of induced control cells. Acetylene reduction assays indicated a significantly higher rate of nitrogen fixation in plants inoculated with the trpPO-dctA fusion strain compared with the control. Despite this apparent increase, the plants had the same top dry weights as those inoculated with control cells.

Bacterial Proteins↗
PubMed1992

Cocaine use and withdrawal: the effect on sleep and mood.

Three recreational cocaine users (age, 26.7 years), after one adaptation night, spent 5 days and nights in the laboratory where their EEG, EOG, and submental EMG were recorded during all of their sleep. On the second afternoon and evening of the study, subjects used an estimated 1 to 2 g cocaine intranasally. They all slept between 2:00 A.M. and 9:00 A.M. that night. Blood samples were drawn each evening and morning. Absolute plasma cocaine levels and patterns of elimination were consistent with subjects report of dose and time of administration. Mood ratings were made repeatedly throughout the study. There was suppression of REM sleep during the use of cocaine followed by a rebound which is specific to REM sleep and is not seen in other stages of sleep. REM variables subsided to normal levels on the third recovery night following cocaine use.

Adult↗
PubMed1992

Cutaneous manifestations of Sjögren's syndrome.

The major mucous membrane and cutaneous manifestation of Sjögren's syndrome (SS) is xerosis. Severe dryness of the eyes, mouth, nasal passage, and vagina produce many annoying symptoms, including photophobia, burning and itching of the eyes, alterations in taste and smell, recurring nonallergic bacterial sinusitis rhinitis, and dysparunia. SS patients frequently complain of dryness of lips and soreness and a burning sensation of the tongue and oral mucosa. SS patients also complain of dryness of their hair and note a decrease in luster, and severe dryness of the skin is frequently accompanied by pruritus.

Humans↗
PubMed1991

Detection of specific polymerase chain reaction product by utilizing the 5'----3' exonuclease activity of Thermus aquaticus DNA polymerase.

The 5'----3' exonuclease activity of the thermostable enzyme Thermus aquaticus DNA polymerase may be employed in a polymerase chain reaction product detection system to generate a specific detectable signal concomitantly with amplification. An oligonucleotide probe, nonextendable at the 3' end, labeled at the 5' end, and designed to hybridize within the target sequence, is introduced into the polymerase chain reaction assay. Annealing of probe to one of the polymerase chain reaction product strands during the course of amplification generates a substrate suitable for exonuclease activity. During amplification, the 5'----3' exonuclease activity of T. aquaticus DNA polymerase degrades the probe into smaller fragments that can be differentiated from undegraded probe. The assay is sensitive and specific and is a significant improvement over more cumbersome detection methods.

Base Sequence↗
PubMed1991

Oral contraceptive (OCP) use increases proliferation and decreases oestrogen receptor content of epithelial cells in the normal human breast.

The effect of ingestion of oral contraceptives (OCP) on cell proliferation and oestrogen (ER) and progesterone receptor (PR) expression of the epithelial cells of the normal human breast was compared with findings in controls not taking OCPs. Histologically normal breast tissue was removed during operation for fibroadenoma or reduction mammoplasty in 216 women whose mean age was 28.1 +/- 8.5 years (+/- SD range 14-53 years). During natural cycles the mean proportion of cells expressing ER was 3.94 +/- 3.71 (% mean +/- SD, range 0-20.8, n = 51), while of those expressing PR it was 12.1 +/- 7.1% (range 3.0-36.1, n = 47). There was a significant decline in ER during the menstrual cycle [p = 0.001 by multiple linear regression (MLR)], but there was no significant change in the proportion which expressed PR. The mean proportion of proliferating cells (LI) was 2.50 +/- 2.42 (range 0-11.5, n = 147). There was a significant increase of LI during the cycle (p = less than 0.001, MLR) and a significant inverse relationship between LI and ER (r = -0.29, p less than 0.01). Use of the OCP significantly reduced the number of cells which expressed ER and increased the LI earlier in the cycle. No effect of OCP use on the number of PR+ cells was detectable. We conclude that significant changes in the proportions of ER+ and proliferating cells occur during natural menstrual cycles. These changes are perturbed by ingestion of OCPs, so that there is greater suppression of ER and a longer period of high proliferation during the menstrual cycle. These results may explain the relationship between OCP use and the possible risk of breast cancer.

Adolescent↗
PubMed1991

Erotic gender differentiation in pedophilia.

Five groups of males were compared on penile volume changes elicited from viewing short movie strips and slides of nude children and adults of both genders. Subject groups were sex offenders against adult females, volunteer controls who erotically preferred adult females, volunteer controls who erotically preferred adult males, heterosexual pedophiles, and homosexual pedophiles. Pedophiles differentiated erotically between females and males less than males who erotically preferred physically mature partners.

Choice Behavior↗
PubMed1991

Reversed polarity of Na(+) -K(+) -ATPase: mislocation to apical plasma membranes in polycystic kidney disease epithelia.

Autosomal dominant polycystic kidney disease (ADPKD) is a genetic disorder in which renal tubules become enormously enlarged due to fluid accumulation. Na(+) -K(+) -ATPase was compared in normal and cystic regions of whole kidneys and in confluent primary cultures of microdissected renal tubule and cyst-lining epithelia. Immunostaining with antibodies directed against the Na(+) -K(+) -ATPase catalytic alpha-subunit was confined to apical, luminal plasma membranes of ADPKD epithelia, which was a complete reversal of the normal renal tubule polarized location in basolateral membranes. Mislocated Na(+) -K(+) -ATPase was shown to be functionally active, because identical intense apical staining was observed by use of a cytochemical assay. In addition, biochemical assays showed a significant increase in these ouabain-inhibitable Na(+) -K(+) -ATPase specific activity levels in ADPKD kidneys compared with age-matched normal kidneys. Specific binding of [3H] ouabain was not only increased but also confined to the apical membrane vesicles prepared from cystic regions of ADPKD kidneys compared with normal age-matched controls, in which binding was confined to basolateral membrane vesicles. Although steady-state levels of Na(+) -K(+) -ATPase alpha- and beta-subunit in mRNAs were increased somewhat in ADPKD kidneys, this alone was not sufficient to account for the observed activation. Confluent ADPKD epithelia grown on dual-chamber, permeable membrane supports also showed reversed polarity of 22NaCl vectorial transport, because this was from basal to apical media compartments. Because this transport could also be blocked by ouabain, this suggested apical Na(+) -K(+) -ATPase was responsible and implicated altered polarity of Na(+) -K(+) -ATPase and resultant Na+ secretion as a mechanism for cyst formation in ADPKD. Because no reversal of polarity of other basolateral or apical membrane proteins was detected, an intracellular sorting defect specific for Na(+) -K(+) -ATPase is proposed.

Biological Transport↗
PubMed1991

Transcriptional regulation of the int-2 gene in embryonal carcinoma cells.

The int-2 gene, which encodes a member of the fibroblast growth factor family, is expressed at specific sites and times during mouse development. In certain embryonal carcinoma cell lines, multiple int-2 transcripts accumulate when the cells are induced to differentiate with retinoic acid and dibutyryl cyclic AMP. Nuclear run-on analyses indicate that the apparent induction of int-2 expression results from an increase in the rate of transcription initiation. Six distinct types of RNA have been delineated, originating from three promoters and terminating at either of two polyadenylation sites. Since each transcript appears to encode the same protein, this complexity may reflect the need for lineage-specific or differentiation-dependent control of expression. By comparing the kinetics of induction and turnover of the different RNA species, we show that the choice of promoter or length of the 3'-untranslated region has no significant effect on the half-lives of the various mRNAs. To further evaluate control at the transcriptional level, we have shown that a 1.7-kilobase fragment of int-2 genomic DNA, when fused to the chloramphenicol acetyltransferase gene, can act as a regulated promoter(s) in differentiated versus undifferentiated embryonal carcinoma cells. This segment of DNA encompasses the three promoter regions previously delineated by RNase mapping plus about 900 base pairs of additional upstream sequences.

Animals↗
PubMed1990

Eosinophilia-myalgia syndrome due to L-tryptophan ingestion. Report of four cases and review of the Maryland experience.

Eosinophilia-myalgia syndrome (EMS) is a recently described clinical entity that has been ascribed to taking over-the-counter preparations of the amino acid L-tryptophan. We describe 4 patients with EMS, 3 of whom presented with eosinophilic fasciitis, and we review the epidemiology of EMS reported in Maryland and discuss the possible pathophysiology of the disease. EMS should be considered in the differential diagnosis of severe myalgia, eosinophilia, and eosinophilic fasciitis.

Administration, Oral↗
PubMed1990

Immunohistochemical localization of cholecystokinin in the medial preoptic area and anterior hypothalamus of the Brazilian gray short-tailed opossum: a sex difference.

We have studied the anatomical localization of cholecystokinin-like immunoreactivity (CCK IR) in somata and fibers in the medial preoptic area (MPA) and anterior hypothalamus (AH) of the Brazilian gray short-tailed opossum, (Monodelphis domestica). With the aid of an avidin-biotin, nickel-enhanced, immunohistochemical technique, CCK IR neuronal elements were found within the MPA and AH. A large number of CCK IR cell bodies were located in the MPA of colchicine-treated opossums. The MPA also contained a CCK IR fiber plexus. Quantitative image analysis revealed that the periventricular preoptic area of noncolchicine-treated male opossums had a significantly higher percent of blocked light measurements than that of the noncolchicine-treated females, indicating a higher density of CCK IR neuronal elements in the males. Neuronal fibers and somata containing CCK IR were also found within the periventricular hypothalamic nucleus (Pe), and the suprachiasmatic nucleus (SCh). These results show that CCK IR neuronal elements are found within the MPA and AH of the Brazilian short-tailed opossum. Furthermore, there is a sexually dimorphic distribution of CCK IR elements within the MPA of this small marsupial.

Animals↗
PubMed1990

Altered rheological properties of blood following administrations of tissue plasminogen activator and streptokinase in patients with acute myocardial infarction.

Tissue blood flow is determined by rheological properties of blood as well as by vascular resistance. In acute myocardial infarction patients who participated in the TIMI I trial, we compared the effects of recombinant tissue plasminogen activator (rt-PA) and streptokinase (SK) on blood rheological properties and plasma fibrinogen concentration. Blood viscosity was determined by using a coaxial cylinder viscometer at shear rates, gamma, of 0.01-200 sec-1. Red blood cell (RBC) deformability was studied by filtration through polycarbonate microsieves with pore size of 3 and 5 microns. Therapy with rt-PA resulted in slight decreases but statistically significant in blood viscosity from 5.2 +/- 0.5 to 4.9 +/- 0.4 cP (gamma = 52 sec-1), plasma viscosity from 1.36 +/- 0.09 to 1.32 +/- 0.06 cP, and plasma fibrinogen from 0.26 +/- 0.04 to 0.21 +/- 0.03 g/dl. SK therapy resulted in reductions in blood viscosity from 5.1 +/- 0.5 to 4.6 +/- 0.3 cP, plasma viscosity from 1.26 +/- 0.10 to 1.16 +/- 0.03 cP, and fibrinogen from 0.26 +/- 0.06 to 0.10 +/- 0.05 g/dl. Changes observed with SK were significantly greater than those observed with rt-PA (all p less than 0.05), and the differences persisted at 10 days after thrombolytic therapy. RBC deformability was similar in the two groups. The greater reduction of blood viscosity after SK than rt-PA suggests that, for a given degree of arterial patency, myocardial blood flow may be better maintained with SK than rt-PA in patients with acute myocardial infarction.

Blood Proteins↗
PubMed1990

Does sexual abuse in childhood cause pedophilia: an exploratory study.

The reliability of the notion that pedophilia is caused by sexual abuse in childhood was explored by examining retrospective self-reports of 344 males. Included in the study were 77 heterosexual pedophiles, 54 homosexual pedophiles, 51 nonpedophilic sex offenders against children, 36 sex offenders against physically mature females, 75 heterosexual paid volunteers who erotically preferred mature females, and 51 homosexual clients who preferred mature males. For each sex offender the differential diagnosis of an erotic preference for minors vs. a preference for physically mature partners was made by means of the phallometric test of erotic gender and age preferences. The analysis of self-reports confirmed that the proportion of pedophiles who report having been sexually abused in childhood by mature persons is larger than that of men who were not charged for or accused of a sex offense against a child though the difference is relatively small (28.6 vs. 13.9 and 10.7% for the heterosexual pedophiles and the two groups of gynephiles, respectively, and 25.9 vs. 11.8% for the homosexual pedophiles and androphiles, respectively). Further analysis demonstrated, however, that pedophiles who admitted having an erotic interest in children significantly more often claimed that they had been sexually abused as children than pedophiles who did not admit having such feelings. This interdependence renders the reliability of these self-reports questionable.

Adult↗
PubMed1990

The influence of component parts on the performance of urinary sheath systems.

A quasi-experimental trial, yielding 30 data points per system, was carried out to investigate the influence of component parts on the overall performance of urinary sheath systems. Information was obtained on the effect of changing both the sheath and leg-bag. Data from the trial was supported by accurate stock-taking analysis over two periods of 4 weeks' duration when alternative systems were used in a clinical setting. Results suggest that leg-bag design profoundly influences the performance of urinary sheaths. A significant difference in the performance of two urinary sheaths in the presence of the same leg-bag was also observed. The significance of the findings for nursing practice is discussed since the optimum performance, from the components tested, was a 'hybrid' system. A continuing line of investigation is suggested whereby improvements in the composition of urinary sheath systems could be made from nursing research.

Aged↗