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Biomedical subjects

K Skinner

Publications and source records attributed to K Skinner.

At least 19 recordsLinked to original sources
PubMed1996

Adhesion formation after laparoscopic anterior resection in a porcine model: a pilot study.

Although decreased adhesion formation is one of the accepted advantages of laparoscopic colorectal surgery, no prospective studies have been done to support this claim. Therefore, we prospectively assessed adhesion formation following laparoscopic anterior resection of the rectum in a porcine model. Five domestic female pigs underwent the procedure with a double-stapled intracorporeal anastomosis. After completion of the laparoscopic procedure, 50 cm of ileum was retrieved through the right lower port site. Controlled serosal abrasion of the antimesenteric surface was performed using a fresh knife. The abraded loop was returned into the peritoneal cavity and the fascia closed at all port sites. All animals underwent a midline laparotomy 3 weeks later to assess adhesions using a 0-3 score according to the density vascularity, and extent of adhesions. All animals survived the study period. The mean level of the anastomosis was 8 cm (range, 7-10) above the anal verge; all anastomoses were intact and completely healed. None of the animals had adhesions to the port sites. The anastomotic site was completely free of adhesions in four animals, and only one animal (20%) had grade 1 adhesions between the urine horns and the anastomosis. Conversely, all animals had adhesions of the abraded loop involving 60 cm (range, 40-75) of bowel and 7 cm (range, 4-9) of the abdominal wall (remote to the port sites); no other adhesions were noted. In this pilot study, serosal abrasion of the small bowel resulted in severe adhesion formation in the porcine model. However, laparoscopic anterior resection of the rectum in the same animals was associated with only minimal insignificant adhesions. Furthermore, unlike in laparotomy incisions, adhesions to port sites did not occur.

Abdomen↗
PubMed1995

Prevention of tissue injury and postsurgical adhesions by precoating tissues with hyaluronic acid solutions.

The effectiveness of inhibiting serosal tissue damage and preventing surgical adhesions by precoating tissues with dilute solutions of hyaluronic acid (HA) was evaluated in a rat cecal abrasion model. This study was performed at three independent laboratories using the same protocol. Three hundred and seventy-five adult rats were divided into five treatment groups (125 animals at each study site): 0.1% HA, 0.25% HA, 0.4% HA, phosphate-buffered saline solution (PBS), and no solution. The abdominal cavity of each animal was precoated with 4 ml of test solution or no solution, prior to a controlled abrasion of the cecum. One week later, the animals were sacrificed and adhesions were scored on a 0-4 scale. The data were pooled because no statistical difference was found in the trends at the three study sites. The PBS precoating and no tissue precoating treatment groups had the same high incidence of cecal adhesions, which was significantly higher than the incidence of adhesions in the HA treatment groups. As the HA concentration in the precoating solution increased from 0% (PBS group) to 0.4% HA, the mean incidence of cecal adhesions decreased in a concentration-dependent manner from 1.6 +/- 0.11 to 0.7 +/- 0.09 (P < 0.001). The percentage of animals with no cecal adhesions increased from 11% in the PBS group to 50% in the 0.4% HA treatment group (P < 0.001). In a separate histological study employing 150 rats, HA solutions significantly inhibited serosal tissue damage and ameliorated the inflammatory response due to abrasion and desiccation compared to that with no coating or precoating with buffered saline. Together, these studies demonstrate that tissue precoating with dilute HA solutions reduces damage to serosal tissues during surgery and thereby limits formation of postsurgical adhesions.

Administration, Topical↗
PubMed1993

Depression among female registered nurses.

Depression, the most frequently diagnosed psychiatric illness, is characterized by feelings of sadness, pessimism, self-dislike and loss of energy, motivation and concentration. The relationship of self-esteem, assertiveness and anxiety to depression is studied in a group of female nurses. Recognizing predisposing factors in this high-risk group can begin a process to treat this illness.

Adult↗
PubMed1991

Parent satisfaction survey: paediatric physiotherapy services.

The aims of the survey were: to obtain data on children being seen in the department in order to determine whether the needs of parents and children are being met; to discover parents' attitudes to 'parent-based' treatment; and to establish whether physiotherapists' expectations of what parents can do at home are realistic. A parent satisfaction survey was developed and sent to outpatients who had attended the physiotherapy department in the previous 6 months. Results were collated and analysed in the areas of: referral source; appointments; treatment; and general opinion. The results are reported in detail and discussed. Results are generally positive and indicate that the physiotherapists are catering for the needs of parents and children, and have appropriate ideas of what can be achieved at home. Several areas of potential improvement are identified and discussed.

Child↗
PubMed1986

Changes in prostaglandin transfer across human fetal membranes obtained after spontaneous labor.

Increased prostaglandin E2 production from amnion is thought to be a critical step in the initiation of human parturition. However, it is not known whether amniotic prostaglandin E2 can reach the decidua and/or myometrium. We examined whether prostaglandin E2 could cross the amnion and full-thickness membranes and whether this capacity changed with active labor. Using an in vitro system we found that there was a time-dependent cumulative transfer of total radioactivity and of radioactivity corresponding chromatographically to prostaglandin E2 across amnion and full-thickness membranes. The rate of transfer across the amnion was faster than across full-thickness membranes and varied according to the site of tissue sampling within the uterus. The permeability constant for prostaglandin E2 transfer across full-thickness membranes was significantly higher in tissue collected after the spontaneous onset of labor than in tissue collected at elective cesarean section at term. We conclude that prostaglandin E2 produced in human amnion at term may escape metabolism in the chorion and reach the decidua and/or myometrium.

Decidua↗
PubMed1985

Relation between cyclic adenosine monophosphate and prostaglandin output by dispersed cells from human amnion and decidua.

We have examined the ability of activators of adenylate cyclase and cyclic adenosine monophosphate to affect the output of prostaglandins E and F by dispersed cells of amnion and decidua collected from women following spontaneous labor. Cyclic adenosine monophosphate production by amnion and decidua cells was stimulated in a dose-dependent fashion by cholera toxin and by forskolin in the absence or presence of the phosphodiesterase inhibitor 3-isobutyl-1-methyl xanthine. Forskolin and cholera toxin also stimulated prostaglandin E and F output from amnion and decidua cells. Similar effects were seen with cells incubated with dibutyryl cyclic adenosine monophosphate +/- 3-isobutyl-1-methyl xanthine. The beta-adrenergic receptor agonists salbutamol, isoproterenol, and epinephrine all stimulated prostaglandin E and F output from dispersed cells of both tissues. The stimulatory effect of 3-isobutyl-1-methyl xanthine was partially additive with the Ca2+ ionophore A23187. Basal outputs of prostaglandin and outputs stimulated by A23187 and by N6, O2'-dibutyryl adenosine 3':5'-cyclic monophosphate were attenuated by the calmodulin antagonist trifluoperazine in a dose-dependent fashion. We conclude that mechanisms exist for stimulation of adenylate cyclase in human amnion and decidua resulting in enhanced prostaglandin output. This pathway requires basal interaction with Ca2+-calmodulin and may be additive with cyclic adenosine monophosphate-independent mechanisms for prostaglandin stimulation.

1-Methyl-3-isobutylxanthine↗
PubMed1985

The structure of the fourth abdominal ganglion of the crayfish, Procambarus clarki (Girard). I. Tracts in the ganglionic core.

The organization of the fourth abdominal ganglion of the crayfish, Procambarus clarki, was studied with the light microscope in serial sections stained with osmium ethyl gallate. This ganglion is composed of a ventral rind of somata and a core of alternating layers of through-tracts and commissures. The longitudinal tracts of the ganglion are named according to the system in use for the orthopteran insects, because the basic plans of the crustacean and insect ventral ganglia exhibit striking anatomical parallels. The dorsal tracts are the largest and the most regular in their path through the ganglion. In the ventral posterior quadrant of the ganglion the tracts diverge from the basic plan to pass around the major synaptic neuropil and the bases of the peripheral nerves. This paper reports the three-dimensional anatomy of the major longitudinal through-tracts, internal tracts and commissures, and bases of peripheral nerves. Landmark features of the ganglion--including the tracts, the major artery of the vascular system, the shape of the ganglionic core in section, and prominent single cells, all of which make it possible to recognize specific regions of the ganglion--are described.

Animals↗
PubMed1985

The structure of the fourth abdominal ganglion of the crayfish, Procambarus clarki (Girard). II. Synaptic neuropils.

Four discrete regions of synaptic neuropil in the crayfish fourth abdominal ganglion are described by light and electron microscopy. The largest is the horseshoe neuropil, a horseshoe-shaped mass of synaptic glomeruli that lies horizontally in the ventral ganglionic core. This neuropil has a substructure of three rings of fused glomeruli associated with the entry of small axons from the first and second nerve roots. The lateral neuropils are large, paired bulges of neuropil that define the sides of the ganglionic core. They contain neuronal profiles of various sizes, filled with clear or dense-cored vesicles. The neurons are randomly oriented except for occasional dendritic bundles. The tract neuropil is ultrastructurally similar to the lateral neuropils but it is distributed among the largest axons of the through-tracts and commissures. The midline neuropils are small, U-shaped clumps of uniformly sized neuronal profiles that contain large numbers of dense-cored vesicles and distinctive lamellar inclusions.

Animals↗
PubMed1985

Prostanoid concentrations in maternal/fetal plasma and amniotic fluid and intrauterine tissue prostanoid output in relation to myometrial contractility during the onset of adrenocorticotropin-induced preterm labor in sheep.

Prostanoid [prostaglandin (PG)] concentrations were measured in ovine maternal and fetal plasma and amniotic fluid during the onset of preterm labor induced by the administration of a pulsatile infusion of ACTH-(1-24) (P-ACTH; 66.7 ng/min for 15 min every 2 h) to the fetus and in saline-infused controls. P-ACTH administration stimulated a change in intra-uterine pressure from type A-activity, characterized by sustained increases of low amplitude, to type B labor-like activity of short duration, high amplitude (greater than or equal to 10 mm Hg) increases which occurred between 12 and 8 h before the onset of labor. PGF2 alpha and/or PGFM (13,14-dihydro-15-keto PGF2 alpha) concentrations increased consistently in all fluids 16 h or earlier before labor. All PGs increased in fetal carotid arterial plasma (PGE2 greater than PGF2 alpha) and amniotic fluid, and the relative increases in each PG were similar. However, PGF2 alpha and PGFM selectively increased in maternal vena caval and aortic plasma, whereas smaller or negligible increases in the prostacyclin hydrolysis metabolite 6-keto PGF1 alpha (6KF) and PGE2 were noted. The output of PGs E2 and F2 alpha (picograms per 10(5) cells/8 h) increased 1.6- and 1.7-fold, respectively, by cells dispersed from the chorioallantois of P-ACTH-treated animals compared to that in control animals infused with saline for 100 h. From fetal cotyledons, these increases were 2.4-fold (P less than 0.05) and 3.6-fold, respectively. No significant changes occurred in 6-keto PGF1 alpha output from any tissue or PGE2 or PGF2 alpha output from amnion or maternal cotyledons. We conclude 1) that PGs increase in all fluids before the increase in uterine mechanical activity during induced preterm labor, implying that PGs mediate this event and are not a result thereof; 2) that syntheses of PGs E2 and F2 alpha increase similarly in intrauterine tissues with the onset of labor; and 3) that a selective increase in PGF2 alpha, a myometrial stimulatory PG, occurs exclusively in maternal plasma, suggesting that endoperoxide conversion to PGF2 alpha is specifically enhanced during parturition or suggesting the existence of an intrauterine tissue source of 9-keto PG reductase.

6-Ketoprostaglandin F1 alpha↗
PubMed1984

Early changes in prostaglandin concentrations in ovine maternal and fetal plasma, amniotic fluid and from dispersed cells of intrauterine tissues before the onset of ACTH-induced pre-term labour.

The changes with time in intrauterine tissue production and concentrations of PGE-2, PGF-2 alpha, 6-keto PGF-1 alpha and PGFM (13,14-dihydro-15-keto PGF-2 alpha) in maternal and fetal plasma and amniotic fluid were investigated during the first 72 h of pulsatile administration of ACTH1-24 to chronically catheterized fetal sheep. By 72 h there were no changes in the frequency, maximum amplitude or duration of uterine contractions compared to preinfusion values. Basal concentrations of PGE-2 in maternal and fetal plasma were generally higher than those of PGF-2 alpha, while 6-keto PGF-1 alpha values were intermediate. The concentrations of all PGs increased in amniotic fluid during ACTH infusion. In fetal plasma and in maternal vena caval plasma, however, there were significant increases only in PGF-2 alpha and PGFM. No changes were observed in plasma concentrations for any PG during saline infusion. The mean output of PGE-2, PGF-2 alpha and 6-keto PGF-1 alpha by dispersed cells prepared from chorioallantois and fetal and maternal cotyledons was consistently higher after ACTH for 72 h than from saline-infused animals, although significance (P less than 0.05) was achieved only for PGE-2 in chorioallantois . There are 3 conclusions. (1) Increases in ovine intrauterine tissue PG production precede the occurrence of increased myometrial contractile activity after ACTH treatment of fetal sheep. The results imply a causal relationship between rising PG and later myometrial contractions, rather than PG changes resulting from enhanced uterine activity. (2) The major site(s) of increased PG output in vitro from endogenous precursors are fetal structures, especially the chorio-allantoic membranes. (3) Although PGE-2 may be the major circulating PG during late gestation, there is a selective increase in plasma PGF-2 alpha concentrations before the onset of delivery.

Adrenocorticotropic Hormone↗
PubMed1983

Estradiol-17 beta and 2-hydroxyestradiol-17 beta-induced differential production of prostaglandins by cells dispersed from human intrauterine tissues at parturition.

Prostaglandin (PGE, 6-keto PGF1 alpha) output by cells dispersed from human amnion and decidua in the presence of increasing levels (0-5000 ng/ml) of estradiol-17 beta (E2) or 2-hydroxyestradiol-17 beta (2-OH E2) was studied in relation to parturition. Tissues were obtained from women at term either before (CS) or after (SL) spontaneous labor and vaginal delivery. In the absence of estrogens, the output of both PGs from amnion increased significantly with labor. No significant increase in decidua PG output occurred with labor. Neither estrogen influenced CS amnion PG output. However, both E2 and 2-OH E2 stimulated SL amnion PGE output (2-OH E2 greater than E2) while having no affect on 6-keto PGF1 alpha output. Only the highest dose of 2-OH E2 stimulated PGE output in CS decidua, but both estrogens significantly inhibited 6-keto PGF1 alpha output in this tissue. In SL decidua only 2-OH E2 significantly stimulated PGE, and neither estrogen affected 6-keto PGF1 alpha output. These results might suggest that estrogens modulate PG biosynthesis at the level of endoperoxide to primary PG conversion.

6-Ketoprostaglandin F1 alpha↗
PubMed1983

Prostaglandin output in relation to parturition by cells dispersed from human intrauterine tissues.

Collagenase-dispersed cells from human amnion, chorion, decidua, and placenta have been maintained in short term cultures to study prostaglandin (PG) biosynthesis in relation to parturition. Cells retained metabolic function during the 6-h incubation period, as determined by the apparently linear utilization of radioactive glucose and the formation of tritiated water. All cells synthesized PGs (E, F, and 6-keto F1 alpha) from endogenous precursors. The output of all three PGs significantly increased in amnion and chorion, but not in decidua or placenta, obtained from women who had entered labor spontaneously at term and delivered vaginally (SL) when compared to women at term, but not in labor, delivered by elective cesarean section (CS). For example, PGE output (picograms per 10(5) cells/6 h) increased from 207 +/- 77 (n = 5) to 908 +/- 334 with labor (mean +/- SEM). The addition of indomethacin (10(-7)-10(-5) M) to SL amnion cells significantly decreased (P less than 0.001, by analysis of variance) PGE and PGF, but not 6-keto PGF1 alpha output. Comparison of PGF output with its metabolite, 13,14-dihydro-15-keto PGF2 alpha (PGFM); indicated that PGF values were similar to or higher than PGFM for all tissues other than CS chorion, where PGFM output was significantly greater (142 +/- 63 vs. 486 +/- 95; n = 5; P less than 0.05). PGFM levels in amnion increased with labor [104 +/- 51 (n = 5) to 341 +/- 96 (n = 5); P less than 0.05], suggesting that PG output increased with labor in the fetal membranes as a result of increased synthesis and not decreased metabolism.

6-Ketoprostaglandin F1 alpha↗