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Biomedical subjects

K Jackson

Publications and source records attributed to K Jackson.

At least 73 records · Page 4Linked to original sources
PubMed1997

Regulation of decidual cell and chorion cell production of interleukin-10 by purified bacterial products.

PROBLEM: To determine whether cultured human decidual cells and chorion cells produce interleukin-10 (IL-10) after incubation with purified bacterial products. METHOD OF STUDY: Decidual cell cultures and chorion cell cultures were established by standard techniques. With confluence, monolayers of each culture were incubated with purified bacterial products, including various concentrations of lipopolysaccharide (LPS), lipid A, and lipoteichoic acid (LTA) for 16 hr in quadruplicate. Culture supernatants were collected and assayed for immunodetectable IL-10 by enzyme-linked immunoadsorbent assay (ELISA). RESULTS: Both decidual cell cultures and chorion cell cultures produced significant quantities of IL-10 after stimulation with LPS, lipid A, and LTA. Cultures of decidual cells produced more IL-10 than did chorion cell cultures. CONCLUSIONS: Our data indicate that both maternal decidual cells and fetally derived chorion cells can produce IL-10 after incubation with bacterial virulence factors. This finding contrasts with our previous findings in which chorion cells did not produce IL-10 after stimulation with IL-1 beta, suggesting that chorion cell production after incubation with bacterial products is independent of IL-1 beta. We speculate that the contribution of anti-inflammatory IL-10 production by human gestational tissues to the inflammatory process in these tissues may be overcome or abrogated by the pro-inflammatory process.

Bacterial Infections↗
PubMed1997

Using nursing standards to evaluate competency.

A competency evaluation program uses nursing standards to link performance management, quality improvement and education to patient care outcomes. This program enables nurse managers to capitalize on the data already available to them and helps meet the Joint Commission on Accreditation of Healthcare Organizations standards. An orientation competency assessment and an annual competency evaluation are provided.

Accreditation↗
PubMed1996

Use of data from a hospital online medical records system by physicians during preanesthetic evaluation.

OBJECTIVE: There is no data on the use of hospital-wide online medical record (OLMR) systems by anesthesiologists. We measured how often anesthesiologists accessed the OLMR database maintained by the hospital, how often data was copied from this database into the clinic's computer system, and how much data was copied. METHODS: In a preanesthetic evaluation clinic that has a computerized evaluation system designed for physician-entered data, a graphical user-interface prototype link provided access to the hospital OLMR database for users and was studied over a 37-day period. The software allowed the user to search the OLMR system by patient name, retrieve a text listing of the patient's record, and then copy and paste desired information into the forms of the preanesthetic system. Using embedded routines, we recorded how many times physicians searched for and retrieved medical records from the hospital OLMR database, as well as how many times they copied data to the preoperative database. As a measure of how much data was copied, the number of characters was also recorded. RESULTS: Of 1,080 patients evaluated in the clinic during the study period, electronic searches of the hospital OLMR database for 221 patients (20.5%) were noted. Of these searches, 208 (94.1%, or 19.3% of 1,080 patients) successfully retrieved data from the patient's record. Data was copied for 170 patients - 81.7% of the successful searches. Of 7,525,153 characters retrieved, 262,269 were copied-an average of 1,543 characters per instance of copying. CONCLUSION: We conclude that anesthesiologists, given even crude graphical access to a hospital OLMR data-base, will retrieve and copy data, potentially increasing the accuracy of the medical records and saving time.

Anesthesiology↗
PubMed1996

Growth hormone, gonad development, and steroid levels in female carp.

The pituitary and plasma growth hormone (GH) levels of female carp (Cyprinus carpio L.) were measured in fish of various sizes and degrees of maturity, and were matched against the levels of 17 beta-estradiol (E2), testosterone (T), 17 alpha-hydroxyprogesterone (17-P), and progesterone (P) in the ovary and plasma. The short-term action of the above hormones and 17 alpha, 20 beta-dihydroxy-4-pregnen-3-one (17,20-P) on the release of GH was examined in vitro in primary culture pituitary cells. The gonadosomatic index (%GSI) increased rapidly in specimens when they had attained 900 +/- 50 g body weight (BW). The pituitary and plasma GH levels increased between 150 and 600 g BW (when oocytes reached the stage at which lipoprotein appeared in the cytoplasm), but at 900 g BW (with oocytes in vitellogenesis) the plasma GH dropped, while pituitary GH remained high. E2 increased with BW, reaching its maximum at 600 and 900 g BW in the ovary and plasma, respectively. Similar patterns were found in the levels of T and P, both hormones reaching their maximum levels at 900 g BW. The level of 17-P was very low and did not increase in proportion to BW. The application of various concentrations of different steroids on a primary culture of pituitary cells led to release of GH. The highest degrees of release were obtained from 10(-6) and 10(-7) M E2, 10(-6) M T, 10(-7) M 17-P and 10(-8) M 17,20-P. In all these cases, hormone treatment effected higher release of GH than was found in the control. A model of the relationship between GH and the steroids associated with maturation is proposed.

Animals↗
PubMed1996

Token reinforcement, choice, and self-control in pigeons.

Pigeons were exposed to self-control procedures that involved illumination of light-emitting diodes (LEDs) as a form of token reinforcement. In a discrete-trials arrangement, subjects chose between one and three LEDs; each LED was exchangeable for 2-s access to food during distinct posttrial exchange periods. In Experiment 1, subjects generally preferred the immediate presentation of a single LED over the delayed presentation of three LEDs, but differences in the delay to the exchange period between the two options prevented a clear assessment of the relative influence of LED delay and exchange-period delay as determinants of choice. In Experiment 2, in which delays to the exchange period from either alternative were equal in most conditions, all subjects preferred the delayed three LEDs more often than in Experiment-1. In Experiment 3, subjects preferred the option that resulted in a greater amount of food more often if the choices also produced LEDs than if they did not. In Experiment 4, preference for the delayed three LEDs was obtained when delays to the exchange period were equal, but reversed in favor of an immediate single LED when the latter choice also resulted in quicker access to exchange periods. The overall pattern of results suggests that (a) delay to the exchange period is a more critical determinant of choice than is delay to token presentation; (b) tokens may function as conditioned reinforcers, although their discriminative properties may be responsible for the self-control that occurs under token reinforcer arrangements; and (c) previously reported differences in the self-control choices of humans and pigeons may have resulted at least in part from the procedural conventions of using token reinforcers with human subjects and food reinforcers with pigeon subjects.

Animals↗
PubMed1995

[A new thrombocyte aggregation-inhibiting and fibrinolysis-promoting synthetic molecule: RGDF (Arg-Gly-Asp-Phe) coupled with the carboxyterminal antiplasmin peptide].

OBJECTIVE: Synthesize such hybrid peptides, which contain the RGD (Arg-Gly-Asp) sequence coupled with another peptide containing lysine residues in special positions, to inhibit simultaneously platelet activation and promote fibrinolytic processes. DESIGN: The in vitro haemostasis modifying properties of the synthesized peptides were tested with ADP induced platelet aggregation, in vitro plasmin generation tests and fibrin-clot lysis assays. RESULTS AND CONCLUSIONS: RGDF (Arg-Gly-Asp-Phe) coupled with the carboxyterminal antiplasmin peptide (RGDFAP hybrid molecule) has a common concentration range for inhibiting platelet activation and increase plasmin generation along with accelerated in vitro fibrin-clot lysis.

Fibrinolysis↗
PubMed1995

Circadian blood pressure variation versus renal function.

Several published reports describe an abnormal circadian blood pressure profile in chronic renal failure subjects. Factors other than renal failure, including age, diagnosis of diabetes mellitus, autonomic dysfunction, and race, also may affect circadian blood pressure profiles. To further elucidate the relationship between renal function and circadian blood pressure variation, we compared day/night circadian blood pressure changes in three groups of male veteran hypertensive patients: group A, creatinine clearance (CC) > 80 mL/min, n = 20; group B, CC 20 to 80 mL/min, n = 19; and group C, CC < 20 mL/min, n = 14. We use postural changes in catecholamines, renin, and aldosterone as a measure of autonomic function. No significant difference in day/night percent change in systolic, diastolic, mean arterial pressure (MAP), or heart rate was seen by renal function group. Regression analysis using age, diagnosis of diabetes mellitus, postural hormonal changes, and creatinine clearance found race to be the only significant predictor of the day/night percent change in MAP (P < 0.05). Compared with whites, black subjects had higher nocturnal heart rates (P = 0.01); smaller day/night heart rate changes (P = 0.03); significantly higher diastolic blood pressure (P = 0.01); and a trend toward smaller day/night change in diastolic blood pressure (P = 0.06). In conclusion, renal function level does not influence day/night blood pressure changes. The blunting or reversal of the normal circadian blood pressure pattern seen in some chronic renal failure hypertensive subjects may be attributable to the association between chronic renal failure and cofactors associated with abnormal circadian blood pressure, including black race and possibly severity of atherosclerosis.

Aldosterone↗
PubMed1995

The effect of sleep intervals on analysis of 24-h ambulatory blood pressure data.

Twenty-four hour blood pressure exposure and circadian blood pressure variability may be important predictors of hypertensive end-organ damage. Since sleep is a major determinant of circadian blood pressure decline, day/night blood pressure changes may be affected by sleep intervals. The current study compares 24-h blood pressure results with and without adjustment for patient-specific sleep intervals. Forty male hypertensive patients (22 with renal insufficiency and 18 with normal renal function) underwent 24-h blood pressure study with SpaceLabs 90207 monitors. They also filled out sleep questionnaires to evaluate time awake and asleep during the day and night intervals. Data was analyzed with and without adjustment for daytime asleep and nighttime awake intervals. The percent change in systolic, diastolic, and mean arterial pressure as well as heart rate was not different statistically or clinically with or without adjustment for sleep intervals. Nevertheless, there was a progressive increase in the day versus night percent change in these hemodynamic parameters with adjustment for sleep intervals. When we used arbitrary cut-offs to define "non-dipper", ie, less than 10% drop in a given hemodynamic parameter, and used patient-specific sleep intervals, clinically and statistically different numbers of "non-dippers" were seen versus sleep unadjusted data (19 v 12, using diastolic BP, P < .01). In conclusion, it may not be necessary to adjust for sleep intervals when relating 24-h blood pressure and day/night blood pressure variability to hypertensive end-organ damage. However, arbitrary cut-offs to define "non-dippers" may be greatly and capriciously affected by sleep/awake intervals.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Pressure↗
PubMed1995

Hybrid peptide containing RGDF (Arg-Gly-Asp-Phe) coupled with the carboxy terminal part of alpha 2-antiplasmin capable of inhibiting platelet aggregation and promoting fibrinolysis.

The aim of this study was to synthesize and investigate hybrid peptides which contain the RGD (Arg-Gly-Asp) sequence coupled with lysine residues in special arrangements (antiplasmin carboxyterminal peptide) in an effort to simultaneously inhibit platelet aggregation and promote fibrinolysis. The in vitro haemostatic modifying properties of the synthesized peptides were tested by ADP-induced platelet aggregation, plasmin-generation tests and fibrin-clot lysis assays. The hybrid peptide RGDFAP, composed of RGDF (Arg-Gly-Asp-Phe) coupled to a synthetic peptide residue of the carboxyterminal part of antiplasmin (AP26) inhibited platelet activation and increased plasmin generation and in vitro fibrin-clot lysis.

Amino Acid Sequence↗
PubMed1995

Molecular method for typing Mycobacterium ulcerans.

A cluster of Mycobacterium ulcerans infections has recently occurred on Phillip Island, Victoria, Australia. Previous cases of infection have generally been located around Bairnsdale in southeast Gippsland. The aim of this study was to determine the epidemiological relationship between these strains and other strains originating in Australia and Africa. The previously described plasmid pTBN12 was used as a probe with restriction enzyme-digested chromosomal DNA to differentiate the strains of M. ulcerans. The probe was able to distinguish 11 restriction fragment length polymorphisms (RFLPs). Forty-three strains originating in Victoria were divided into three types, i.e., V1, V2, and V3. The majority of strains (40) yielded a type V1 pattern, including strains from southeast Gippsland. Fourteen strains from Queensland yielded three additional RFLP types, i.e., Q1, Q2, and Q3. Five strains from Benin and seven strains from Zaire yielded five additional RFLP types. It is envisaged that molecular typing of M. ulcerans strains from around the world may have a great impact on understanding of the epidemiology of infection with this organism.

Australia↗
PubMed1995

Retroviral-like sequences specifically expressed in the rat ovary detect genetic differences between normal and transformed rat ovarian surface epithelial cells.

We have identified a repetitive DNA element in the rat genome that we demonstrate to be suitable to detect molecular genetic differences between normal and malignantly transformed rat ovarian surface epithelial cells by genome scanning. With fluorescence in situ hybridization, we show that these elements are widely distributed in the rat genome, and that a member of this family is present within a homogeneously staining chromosomal region of tumorigenic rat ovarian surface epithelial cells. The homogeneously staining chromosomal region infers the presence of an amplified DNA sequence in the tumor cells, and we provide molecular evidence for an amplicon in this DNA by genome scanning using a probe related to these elements. Sequence analysis revealed that these elements have the structural features of retroviral DNA. We show that they are transcriptionally active in the rat ovary, but not in a wide range of other normal rat tissues. In situ hybridization to ovarian tissue sections revealed that the elements are expressed in granulosa and theca interna cells and in the surface epithelial cells adjacent to preovulatory follicles. Based on this property, we refer to these retroviral-like elements as ovary-specific transcribed sequences. Partial sequence analysis of multiple members of this family and the range in transcript sizes strongly suggest that multiple members of this retrovirus-like family are transcriptionally active. We speculate that binding by one or a combination of ovary-specific transcription factors to regulatory sequences within the genomic ovary-specific transcribed sequences units contributes to the tissue specificity of their expression.

Animals↗
PubMed1995

Nocturnal blood pressure measurement: can it be predicted by self-monitoring and is 24-hr BP monitoring clinically important in the treatment of hypertension.

We predict that 24-hour blood pressure data will be required prior to starting treatment in order to receive third-party payment. We are currently performing a cost benefit analysis in patients with mild to moderate hypertension to see the prevalence of inappropriate treatment of hypertension (diagnosed by normal 24-hour BP results) in an outpatient clinic population. We will compare the cost of treating that segment of the population that is inappropriately on treatment to the cost of 24-hour BP monitoring for the entire study population. As a result of this type of analysis, health care payors may require 24-hour BP documentation prior to hypertension treatment for all cases of mild to moderate hypertension.

Blood Pressure Determination↗
PubMed1995

RGDFAP: platelet aggregation inhibitory and profibrinolytic hybrid peptide (RGDF coupled with the carboxy terminal part of alpha 2-antiplasmin) enhances plasminogen binding to platelets.

As published in a recent issue of Blood Coagulation and Fibrinolysis, the hybrid peptide RGDFAP, composed of RGDF (Arg-Gly-Asp-Phe) coupled to a synthetic peptide residue of the carboxy terminal part of antiplasmin (AP26) inhibited platelet activation and augmented plasmin generation and in vitro fibrin clot lysis. This peptide contains an RGD motif which provides linkage to platelet GP IIb-IIIa. The antiplasmin part of the molecule may attach free plasminogen, which in turn increases the amount of platelet surface bound plasminogen, probably yielding enhanced lytic action at the site of thrombus formation. This hypothesis was investigated and confirmed by the results of platelet-plasminogen binding assays, using FITC-labelled antiplasmin antibodies and radioligand binding analysis. Increased platelet-linked plasminogen was detected by a chromogenic method, along with the acceleration of in vitro lysis of platelet-rich clots in the presence of RGDFAP peptide.

Amino Acid Sequence↗
PubMed1994

Analysis of intrabolus forces in patients with Zenker's diverticulum.

This report presents 10 patients with Zenker's diverticulum who were evaluated with simultaneous solid-state manometry and fluoroscopy. With this method, intrabolus forces are determined. Each patient had abnormal intrabolus forces regardless of the size of the diverticulum and cricopharyngeal muscle dysfunction. In the literature, there has been conflicting manometry results when studying Zenker's diverticulum. The use of analysis of intrabolus forces increases the sensitivity of manometric evaluation. This study establishes pressure abnormality in the pharyngoesophageal segment of patients with Zenker's diverticulum. The pathogenesis of Zenker's is presented based on these findings.

Deglutition↗
PubMed1994

Effects of raclopride treatment on plasma and CSF HVA: relationships with clinical improvement in male schizophrenics.

Thirty-two acutely psychotic, male schizophrenic patients received raclopride, at 2, 6, or 12 mg/day, or haloperidol, 15 mg/day for 4 weeks after randomized, double-blind assignment. Twenty-six patients, including 19 who had been assigned one of the three doses of raclopride, completed the study. Raclopride, particularly at 12 mg/day, increased CSF homovanillic acid (HVA) at 4 weeks, and plasma HVA at 2 days, of treatment. The clinical response to raclopride was significantly correlated with plasma raclopride concentrations and baseline plasma HVA concentrations. Although raclopride is a substituted benzamide with atypical properties in animals, these results suggest that the doses of raclopride required for clinical efficacy and elevation of clinical indices of brain dopamine turnover are similar.

Adult↗