Search PubMed⌕ Search

Biomedical subjects

K M Wilson

Publications and source records attributed to K M Wilson.

At least 19 recordsLinked to original sources
PubMed1995

Age differences in the formation of equivalence classes.

In order to investigate the relationship between stimulus equivalence class formation and age differences, two groups of elderly (ages 62-81) and young (ages 19-22) adult men and women mastered a series of simple and conditional discriminations. Subsequently, they were administered a test for the emergence of equivalence relations. There was a significant age difference in the emergence of equivalence relations, with the elderly subjects less likely to demonstrate equivalence relations. Measures of response latencies evidenced a general slowing of behavior for the elderly group across tasks. There were no gender or Age by Gender interactions. Possible explanations for the age differences are discussed.

Adult↗
PubMed1995

Thyroplasty using a silicone elastomer implant.

Silicone has been used in a variety of forms as a replacement for soft tissue for more than three decades in the United States. The safety of this practice has come under scrutiny recently as our knowledge of the local, systemic, and immune effects of silicone has expanded. Contrary to what was once thought, silicone is not biologically inert. Silicone elastomer, however, has not been implicated in the development of systemic immune disease or carcinogenesis. The evidence to date supports the continued use of silicone elastomer implants in the larynx. It is clear, however, that continued investigation into the basic biologic properties and mechanisms of the host-silicone implant interaction is warranted.

Humans↗
PubMed1992

Hyperhydrating effect of acute administration of angiotensin II in rats.

Water intake, urine output, and fluid exchange (water intake less urine output) were measured in rats at hourly intervals for 7 hours and at 24 hours following acute administration of angiotensin II (AII, 200 micrograms/kg SC). AII induced the expected abrupt increase in water intake and a more gradual increase in urine output. The change in fluid exchange (fluid exchange of the AII-treated group less fluid exchange of controls) became positive within the first hour after treatment with AII, decreased linearly with time, and reached 0 at approximately 10 to 12 hours after treatment with AII. When AII was administered intracerebroventricularly (50 ng), similar results were observed. In this case, the change in fluid exchange (delta F) reached 0 in about 6 hours. Imposition of a water load (1% of body weight, IP) on the group receiving AII SC failed to affect the time required for delta F to reach 0 if the water load was disregarded. However, inclusion of the load as a part of intake extended the time the rats remained in positive fluid balance beyond that of the nonloaded, AII-treated control group. In the case of the larger water load (3% of body weight, IP), delta F returned to that of controls in about 4 to 5 hours if the water load was disregarded. However, inclusion of the load as part of intake extended the period of hyperhydration well beyond that of both the nonloaded, AII-treated group and the AII-treated group given the 1% load.(ABSTRACT TRUNCATED AT 250 WORDS)

Angiotensin II↗
PubMed1992

Observations using antiendotoxin antibody (E5) as adjuvant therapy in humans with suspected, serious, gram-negative sepsis.

OBJECTIVE: To evaluate the safety and efficacy of E5 (Xomen-E5), a murine monoclonal immunoglobulin M antibody, in reducing mortality in patients with serious Gram-negative infections. Phase II, single-site study. DESIGN: Randomized, double-blind, placebo-controlled study. SETTING: Surgical, neurosurgical and medical ICUs, comprising approximately 30 beds in a multidisciplinary university hospital. PATIENTS: Patients with clinical evidence of serious infection admitted to the ICU for monitoring of vital signs and for intensive care nursing. Of the 39 patients enrolled in the study, 23 had documented Gram-negative infection. METHODS: Patients suspected of having life-threatening Gram-negative infections received one of two doses of E5 or placebo. Safety and efficacy were assessed by survival on days 3, 7, and 21, appearance of adverse reactions, development of antimurine antibodies, and effects on BP, urine output, WBC count, and temperature. MEASUREMENTS AND MAIN RESULTS: Mortality rate from Gram-negative infection 3 days after the last drug (or placebo) infusion was two (22%) of nine deaths in the placebo group compared with 0 of nine for E5 2.5 mg/kg and 0 of five for E5 7.5 mg/kg. At 21 days after therapy, three patients treated with E5 had died. Only one of these three deaths resulted from infection. Eight of 15 E5 patients tested had immunoglobulin G antimurine antibodies by 3 wks after therapy began, but all were asymptomatic. CONCLUSIONS: E5 was well tolerated and may have the potential to reduce early morbidity and the mortality rate in seriously ill patients with Gram-negative infections. Results from larger phase III studies are needed to confirm these findings.

Acute Disease↗
PubMed1991

Rapid whole blood assay for HIV-1 seropositivity using an Fab-peptide conjugate.

A rapid whole blood test has been developed for circulating antibodies to human immunodeficiency virus type 1 (HIV-1), based on agglutination of autologous red blood cells. Evaluation of the test revealed that 100% of seropositive HIV-1 patients (both asymptomatic and AIDS cases) were detected (n = 94) with a specificity of 99.5% in healthy blood donors (n = 596). The assay uses an Fab fragment of a monoclonal antibody specifically directed against glycophorin (a transmembrane glycoprotein present on the surface of human red blood cells). This anti-red blood cell Fab is conjugated via the inter-heavy chain cysteines to a synthetic peptide corresponding to the immunodominant epitope of the HIV-1 viral coat protein gp41 (579-613). Addition of this reagent to 10 microliters of whole blood results in the Fab-peptide conjugate coating the red blood cells with peptide. In the presence of circulating antibodies to the HIV-1 peptide, red cell agglutination occurs within 2 min. The sensitivity and specificity of this reagent indicate that it is appropriate for use as a rapid diagnostic test for HIV-1 seropositivity.

Agglutination Tests↗
PubMed1991

Synergistic interactions between alpha 1- and alpha 2-adrenergic receptors in activating 3H-inositol phosphate formation in primary glial cell cultures.

Norepinephrine (NE)-stimulated 3H-inositol phosphate (3H-InsP) formation in primary glial cell cultures is thought to be due to alpha 1-adrenergic receptor activation. Surprisingly, the alpha 1-selective agonists phenylephrine and methoxamine showed only 12-21% of the intrinsic activity of NE in activating this response. Although the alpha 2-selective agonist UK 14,304 was itself inactive, inclusion of UK 14,304 increased the response to the alpha 1-selective agonists by about threefold. This increase was concentration-dependent and occurred at all time points examined. 6-Fluoro-NE and alpha-methyl-NE mimicked the effect of NE in glial cultures, although with lower potencies. However, several partial agonists were ineffective in activating this response, in both the presence and absence of UK 14,304. Synergistic interactions were not observed for alpha 1-mediated responses in slices of rat cerebral cortex, either for formation of 3H-InsPs or potentiation of isoproterenol- or adenosine-stimulated cyclic AMP accumulation. Both UK 14,304 and phenylephrine inhibited NE-stimulated 3H-InsP formation in concentrations similar to those necessary to activate this response directly. These results suggest that NE activates 3H-InsP formation in primary glial cultures by synergistic actions on both alpha 1- and alpha 2-adrenergic receptors. The agonists UK 14,304 and phenylephrine also can act to inhibit the response to NE competitively.

Adrenergic alpha-Agonists↗
PubMed1991

Bioinequivalence of four 100 mg oral aspirin formulations in healthy volunteers.

The single dose pharmacokinetics of 4 commercially available 100 mg oral aspirin formulations were studied in 6 healthy men and 6 healthy women. Two of the formulations were rapid release ('Cardiprin' 100, 'Platelin') and the other 2 were enteric coated formulations ('Astrix' 100, 'Cartia'). There were marked differences in the plasma concentration-time profiles between the rapid release and the enteric coated formulations. There were no significant differences (p greater than 0.05) in the mean time to achieve maximum aspirin concentrations between 'Cardiprin' 100 (0.48 h) and 'Platelin' (0.35 h), but this was significantly prolonged (p less than 0.001) for 'Astrix' 100 (3.73 h) and even more prolonged for 'Cartia' (6.84 h). Similar between-formulation differences were seen in the areas under the plasma concentration-time curves, for which the rank order was 'Cardiprin' 100 (1.60 mg/L.h) = 'Platelin' (1.54 mg/L.h) greater than 'Astrix' 100 (0.73 mg/L.h) greater than 'Cartia' (0.56 mg/L.h). For 'Cardiprin' 100, 'Platelin' and 'Astrix' 100 plasma aspirin concentrations were below 5 micrograms/L by 7 h after ingestion, whereas for 'Cartia' aspirin was detectable for up to 16 h, giving the appearance of sustained release. The enteric coated formulations produced the greatest variability in the plasma aspirin concentration vs time profiles. The urinary recovery of salicylate was greater than 80% of the administered dose for all 4 formulations. The clinical significance of the marked pharmacokinetic differences observed with these 4 low-dose aspirin formulations is not known.

Administration, Oral↗
PubMed1991

Randomized, double-blind phase II study of anti-endotoxin antibody (E5) as adjuvant therapy in humans with serious gram-negative infections.

Xomen-E5 (E5) is a murine monoclonal IgM antibody (MAb) that binds to the lipid A epitope of endotoxin. The MAb was developed by immunization against the J5 mutant of Escherichia coli. Prior studies in humans have shown safety and T1/2 of 18.4 hours. In this double blind study patients suspected to have life threatening gram-negative infections were randomized to receive 2 doses, 24 hours apart, of placebo (P), 2.5 mg/kg E5, or 7.5 mg/kg E5. Overall 23 patients had a documented serious gram-negative infection and received at least one dose of study drug. Mortality 3 days after last infusion was 2 of 9 for P, 0 of 9 for 2.5 mg/kg, and 0 of 5 for 7.5 mg/kg. By 21 days after therapy one E5 treated patient had died. Wheezes occurred in one E5 treated patient. Eight of 15 E5 patients treated had IgG anti-murine antibodies by 3 weeks after therapy. These data suggest the need to pursue studies designed to verify that E5 reduced mortality and morbidity in seriously ill patients with gram-negative infections.

Antibodies, Monoclonal↗
PubMed1990

Different pathways of [3H]inositol phosphate formation mediated by alpha 1a- and alpha 1b-adrenergic receptors.

The types of inositol phosphates (InsPs) formed in response to activation of alpha 1-adrenergic receptor subtypes were determined in collagenase-dispersed renal cells and hepatocytes by high pressure liquid chromatography separation. In hepatocytes, which contain only the alpha 1b subtype, norepinephrine stimulated rapid (10-s) formation of [3H]Ins(1,4,5)P3 and [3H]Ins(1,3,4)P3 and slower (5-min) formation of Ins(1,4)P2 and Ins(1)P. Selective inactivation of alpha 1b receptors by chloroethylclonidine almost completely blocked the effects of norepinephrine in hepatocytes. In renal cells, which contain both alpha 1a and alpha 1b receptors in a 60:40 ratio, norepinephrine did not significantly increase the size of any peaks until 5 min after agonist activation. At this time, only a peak eluting with Ins(1)P and one eluting shortly after Ins(1,4)P2 were significantly elevated. Incubation with norepinephrine for 2 h caused small but significant increases in peaks co-eluting with Ins(1)P and Ins(1,4,5)P3 in renal cells; however, only the increase in Ins(1)P was inhibited by chloroethylclonidine pretreatment. Extraction under neutral conditions suggested that cyclic InsPs may be the primary compounds formed in response to norepinephrine in renal cells. Removal of extracellular Ca2+ caused a 60% reduction in the InsP response to norepinephrine in renal cells but had no effect in hepatocytes. These results suggest that activation of alpha 1a and alpha 1b receptor subtypes results in formation of different InsPs and that the response to alpha 1a activation may require influx of extracellular Ca2+.

Animals↗
PubMed1990

Effect of aspirin infusions on platelet function in humans.

1. The inhibitory effects of aspirin on platelet function in vitro have been shown to be both time (over 3 h) and concentration (1-10 mumol/l) dependent. 2. To determine if these effects occurred in vivo, four volunteers received intravenous infusions on four occasions, to give constant plasma aspirin concentrations of 0, 1, 2 and 4 mumol/l over 3 h. Infusions were performed at intervals of at least 2 weeks. 3. Before and during the infusions, blood was taken for assay of aspirin concentrations, and measurements of platelet aggregation in response to collagen, adenosine 5'-pyrophosphate and arachidonate. Thromboxane generation after stimulated platelet aggregation and whole-blood coagulation was also measured. 4. At each aspirin concentration, both platelet aggregation and thromboxane generation in response to collagen and arachidonate were inhibited progressively over the 3 h infusion period. Greatest inhibition was seen during the 4 mumol/l infusion, which produced maximal or near-maximal inhibition by the third hour. 5. Thromboxane generated during whole-blood coagulation was similarly inhibited in both a time- and concentration-dependent manner throughout all aspirin infusions. 6. The progressive nature of the inhibition of platelet function with these low aspirin concentrations may be due to either slow aspirin transport across the platelet membrane or delayed interaction with cyclo-oxygenase.

Adenosine Diphosphate↗
PubMed1990

Comparison of alpha 1-adrenergic receptor-stimulated inositol phosphate formation in primary neuronal and glial cultures.

alpha 1-Adrenergic receptor binding sites and norepinephrine-stimulated 3H-inositol phosphate (3H-InsP) accumulation were measured in primary cultures of neurons and glia from 1-day-old rat brains. The density of alpha 1-adrenergic receptor binding sites was approximately three times higher in membranes from neurons compared to glia. Although norepinephrine was slightly more potent in stimulating 3H-InsP formation in neurons than in glia, the maximal response was greater in glial cells. Norepinephrine-stimulated 3H-InsP formation remained constant for [3H]inositol prelabelling periods of 1-14 days in neurons, whereas the response increased with time in glia and was maximal after 7-10 days of prelabelling. Both the incorporation of [3H]inositol into lipid and basal levels of 3H-InsPs were lower in glial cells than in neurons, which accounted for the greater percent stimulation in glia. Pretreatment with phenoxybenzamine decreased norepinephrine-stimulated 3H-InsP formation in a dose-dependent manner in both neurons and glia by decreasing the maximal response without altering potency. HPLC separation showed that similar types of 3H-InsPs were accumulated in neurons and glial cells. These results demonstrate that alpha 1-adrenergic receptors exist on both neurons and glial cells and activate 3H-InsP accumulation in both cell types. Although receptor density is higher in neurons than in glia, the 3H-InsP response is higher in glia. This difference does not appear to be due to different receptor reserves, but may be due to differential coupling mechanisms in the two cell types.

Adrenergic alpha-Antagonists↗
PubMed1990

Alpha 1-adrenergic receptor subtypes and formation of inositol phosphates in dispersed hepatocytes and renal cells.

The ability of alpha 1a- and alpha 1b-adrenergic receptor subtypes to stimulate [3H]inositol phosphate [( 3H]InsP) formation was examined in collagenase-dispersed hepatocytes and renal cells. alpha 1-Adrenergic receptor binding sites were labeled with 125I-BE 2254, and the proportion of alpha 1a and alpha 1b subtypes was determined with chloroethylclonidine (CEC) and WB 4101. Hepatocytes contained only alpha 1b-adrenergic receptors, whereas renal cells had approximately equal proportions of both subtypes. Pretreatment of renal cells with CEC selectively inactivated the alpha 1b subtype, leaving a homogeneous population of alpha 1a receptors. Norepinephrine stimulated [3H]InsP accumulation to a similar extent in both hepatocytes and renal cells. Pretreatment with CEC inactivated this response completely in hepatocytes but only partially in renal cells. WB 4101 was 1000-fold more potent in inhibiting the [3H]InsP response in renal cells than hepatocytes; however, some of this difference was due to rapid metabolism of WB 4101 by hepatocytes. After correction for metabolism, WB 4101 was still 11-fold more potent in inhibiting norepinephrine-stimulated [3H]InsP formation in hepatocytes (alpha 1b) than in CEC-pretreated renal cells (alpha 1a). These results demonstrate that both alpha 1a- and alpha 1b-adrenergic receptor subtypes activate formation of [3H]InsP, although the molecular mechanisms by which these responses occur remain to be determined.

Animals↗
PubMed1990

Pertussis toxin inhibits norepinephrine-stimulated inositol phosphate formation in primary brain cell cultures.

Norepinephrine (NE) increased formation of [3H]inositol phosphates ( [3H]InsPs) in primary cultures of neuronal and glial cells from 1-day-old rat brain. This response appeared to be mediated by alpha 1-adrenergic receptors, because prazosin was 40-fold more potent than yohimbine in blocking it. Pretreatment with pertussis toxin (PTX) dose-dependently decreased this response by 70-80%. The IC50 for PTX (7 ng/ml) was similar to that for blocking of alpha 2-adrenergic receptor-mediated decreases in cyclic AMP accumulation in the same cells. PTX pretreatment caused only a small, not statistically significant, inhibition of the [3H]InsP response to the muscarinic cholinergic receptor agonist carbachol in these cells. Radioligand binding studies showed that both neuronal and glial cultures contained mixed populations of alpha 1a- and alpha 1b-adrenergic receptor subtypes. Selective inactivation of the alpha 1b population by chloroethylclonidine reduced NE-stimulated [3H]InsP formation by 25 +/- 6%. Pretreatment with both PTX and chloroethylclonidine caused additive decreases (90 +/- 3%) in the NE response. NE-stimulated [3H]InsP formation was partially dependent on extracellular calcium, because it was decreased 64 +/- 6% by removal of calcium and 56 +/- 13% by addition of 1 mM CdCl2, although it was not affected by 1 microM nifedipine. These results suggest that NE stimulates [3H]InsP formation in neuronal and glial cultures through a pertussis toxin-sensitive guanine nucleotide-binding protein. This response appears to be mediated primarily by the alpha 1a subtype and may be subsequent to calcium influx.

Animals↗
PubMed1989

Tumor necrosis factor-mediated cytotoxicity by tumor-associated macrophages.

We have directly demonstrated that macrophages present within solid EMT6 mammary tumors (of BALB/c origin) produce TNF-alpha (TNF). These tumor-associated macrophages lysed WEHI-164, a TNF-sensitive cell line, very efficiently. This cytotoxicity was abrogated in the presence of anti-TNF antisera. In contrast, EMT6 cells, the tumor from which the macrophages were obtained, were not effectively lysed by the macrophages and were 100-fold less sensitive to lysis by recombinant mouse TNF. Thus, marked heterogeneity exists among tumors regarding sensitivity to TNF-mediated cytotoxicity. Similarly, macrophages which infiltrate into EMT6 multicellular spheroids implanted into the peritoneal cavity as well as free cells within the cavity exhibited TNF-mediated cytotoxicity of WEHI-164 cells, but failed to lyse EMT6 cells. The kinetics of lysis by these cells was similar to that of recombinant mouse TNF.

Animals↗
PubMed1989

Sweat gland carcinoma of the hand (malignant acrospiroma).

A case of malignant acrospiroma of the hand is reported. This rare sweat gland carcinoma recurs locally in 50% of patients, with distant metastases occurring in 60% of patients. The prognosis for 5-year disease-free survival is less than 30%. Although the histopathologic findings of tumor-free margins and negative regional lymph node dissection indicate a good prognosis in most carcinomas, they do not guarantee a good prognosis in malignant acrospiroma because of the aggressive characteristics of this tumor.

Adenocarcinoma↗
PubMed1989

Radiation-induced DNA damage and repair in quiescent and proliferating human tumor cells in vitro.

The purpose of this study was to examine radiation-induced DNA strand breakage and repair in quiescent and proliferating human tumor cells in vitro and determine their relationship to radiation sensitivity and potentially lethal damage repair (PLDR). Using centrifugal elutriation we have isolated from fed plateau-phase cultures of HEp-3 human squamous carcinoma cells, relatively pure populations of quiescent and proliferating cells. This was confirmed by both [3H]-thymidine labelling and acridine orange (AO) staining with flow cytometry. Quiescent cells were more sensitive to ionizing radiation (Do = 0.97 Gy) than were proliferating cells (Do = 1.28 Gy). However, quiescent cells showed higher repair of potentially lethal damage (PLDR) than did proliferating cells. Repair of single-strand breaks (ssb) and double-strand breaks (dsb) as measured by filter elution did not differ significantly between quiescent and proliferating cells. For both populations, ssb and dsb repair kinetics and final damage remaining were the same, suggesting that repair of DNA strand breaks is not entirely responsible for the difference in radiation sensitivity between quiescent and proliferating cells.

Carcinoma, Squamous Cell↗