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Biomedical subjects

J Kirkpatrick

Publications and source records attributed to J Kirkpatrick.

At least 37 records · Page 2Linked to original sources
PubMed1997

Portal vein thrombosis in the adult: surgical implications in an era of dynamic imaging.

Extrahepatic portal vein thrombosis (EHPVT) is the leading cause of variceal hemorrhage in patients with healthy livers; however, in an era of dynamic imaging, the incidental discovery of EHPVT places a special burden on the surgeon to understand the surgical implications of the disease in this setting. During the period 1989 to 1995, 23 patients (12 males and 11 females) were found to have EHPVT. In 20 (87%), this was an unexpected finding on ultrasound (11 of 23), abdominal CT scan (9 of 23), or both (9 of 23). In two patients, the diagnosis was suspected and confirmed with angiography, whereas in the other, the lesion was discovered at surgery. Only seven (30%) had hemorrhage as a presenting complaint. More typically (61%), abdominal pain alone or pain with sepsis was the indication for evaluation. In 20 patients (87%), there was an identifiable etiology for the EHPVT. A total of 15 operations were performed on 12 patients (52%), in 7 (4, variceal hemorrhage, and 3, bowel ischemia) as a direct consequence of the EHPVT and in five, for conditions not directly related to the EHPVT. Three of the 23 patients (13%) died, two (17%) following surgery and one (9%) from advanced malignant disease. No patients with hemorrhage (seven), even those who required a shunt for decompression (three) or devascularization (one), died. We found that the diagnosis of EHPVT is usually not related to variceal hemorrhage, but rather, abdominal symptoms that serve as an indication for the imaging study. Three subsets of patients emerged: (1) those requiring no surgery (11 patients), (2) those requiring surgery related to hemorrhage (4 patients), and (3) those requiring surgery for conditions other than varices (8 patients). In any of these circumstances, mortality (13%) was related to the underlying disease process rather than EHPVT. Given the earlier recognition of EHPVT, the natural history of the disease has been altered, with outcome reflecting the underlying disease rather than the sequelae of portal hypertension.

Abdominal Neoplasms↗
PubMed1996

Specific domains of beta-amyloid from Alzheimer plaque elicit neuron killing in human microglia.

Alzheimer's disease (AD) is found to have striking brain inflammation characterized by clusters of reactive microglia that surround senile plaques. A recent study has shown that microglia placed in contact with isolated plaque fragments release neurotoxins. To explore further this process of immunoactivation in AD, we fractionated plaque proteins and tested for the ability to stimulate microglia. Three plaque-derived fractions, each containing full-length native A beta 1-40 or A beta 1-42 peptides, elicited neurotoxin release from microglia. Screening of various synthetic peptides (A beta 1-16, A beta 1-28, A beta 12-28, A beta 25-35, A beta 17-43, A beta 1-40, and A beta 1-42) confirmed that microglia killed neurons only after exposure to nanomolar concentrations of human A beta 1-40 or human A beta 1-42, whereas the rodent A beta 1-40 (5Arg-->Gly, 10Tyr-->Phe 13His-->Arg) was not active. These findings suggested that specific portions of human A beta were necessary for microglia-plaque interactions. When coupled to microspheres, N-terminal portions of human A beta (A beta 1-16, A beta 1-28, A beta 12-28) provided anchoring sites for microglial adherence whereas C-terminal regions did not. Although itself not toxic, the 10-16 domain of human A beta was necessary for both microglial binding and activation. Peptide blockade of microglia-plaque interactions that occur in AD might prevent the immune-driven injury to neurons.

Alzheimer Disease↗
PubMed1995

Validity and reliability of the twenty-eight-joint count for the assessment of rheumatoid arthritis activity.

OBJECTIVE: To investigate the validity of the 28-joint count for assessment of joint involvement in patients with rheumatoid arthritis (RA). METHODS: Joint involvement as determined by the 28- and the 66/68-joint count was compared using data from 735 prospectively studied RA patients. RESULTS: The joints included in the 28-joint count were more commonly involved than other joints, and findings from the 28-joint count correlated highly with those from the 66/68-joint count in all analyses. CONCLUSION: The 28-joint count is a reliable and valid measure for joint assessment. It is easier to perform than the 66/68-joint count, and it addresses the joints that are critically involved.

Arthritis, Rheumatoid↗
PubMed1995

Negotiating two electronic resources for nursing.

The five primary knowledge resource databases available in the Virginia Henderson International Library are reviewed and other menu items are discussed including library services currently under development. This article guides nurse managers to access the library on their own computer. In addition, the opportunities and advantages of the new On-line Journal of Knowledge Synthesis for Nursing are related and requirements for accessing the journal are outlined.

Databases, Bibliographic↗
PubMed1995

Risk factors of adolescent and young adult trauma victims.

BACKGROUND: Repeated injury, or recidivism, because of intentional or unintentional injury is a growing chronic health problem among urban adolescents and young adults in the United States. OBJECTIVE: To describe demographic, social, environmental, psychological, and developmental antecedents and risk-taking behaviors, and to examine their relationships to type of trauma and rate of trauma recidivism in adolescent and young adults in an urban trauma center. METHODS: One hundred adolescent and young adult trauma victims in an urban trauma center were interviewed, using the Adolescent Risk-Taking Instrument, the Brief Anger/Aggression Questionnaire, and the Trauma Risk Factor Interview Schedule. Bivariate correlation, multiple regression, and discriminant function analysis were used to examine the data. RESULTS: Of the sample, 89% experienced trauma related to interpersonal violence, including firearm injuries, stab wounds, and blunt trauma. Male gender, unemployment, past arrest, lower levels of spirituality, and higher levels of anger/aggression and thrill-seeking accounted for 25% of the variance in the number of risk-taking behaviors. Factors such as male gender, past arrest, unemployment, having been a crime victim in the past, lower autonomy, use of weapons, fighting, and no psychological counseling distinguished subjects with firearm-related injuries from subjects with other injury sources. Use of alcohol on weekdays, past arrest, and higher education levels were associated with trauma recidivism, explaining 14% of the variance. CONCLUSIONS: Social/environmental and psychological/developmental variables, as well as risk-taking behaviors, are important correlates of trauma and recidivism. These findings suggest the importance of advocacy for social policies conductive to reducing the risks of violence and trauma and risk-reduction interventions as components of posttrauma care.

Adolescent↗
PubMed1993

Regulation of fibrinolysis by platelet-released plasminogen activator inhibitor 1: light scattering and ultrastructural examination of lysis of a model platelet-fibrin thrombus.

We have investigated the role of plasminogen activator inhibitor 1 (PAI-1) in the regulation of fibrinolysis using a model thrombus composed of thrombin-stimulated platelets, fibrin(ogen), plasminogen, and recombinant tissue-type plasminogen activator. Laser light scattering kinetic measurements showed that clot lysis was significantly delayed both by thrombin-stimulated platelets and their cell-free releasate. This delay in lysis was almost fully reversed by the addition of a PAI-1-specific monoclonal antibody that blocks the ability of PAI-1 to inhibit plasminogen activators. Lysis half-times exhibited a linear dependence on the concentration of PAI-1 antigen present, as determined by enzyme-linked immunosorbent assay (ELISA). Sodium dodecylsulfate-polyacrylamide gel electrophoresis (SDS-PAGE) followed by immunoblotting confirmed the presence of PAI-1 antigen in the platelet releasates. Scanning electron micrographs of the model thrombus components sampled late in lysis showed considerable unproteolyzed fibrin still attached to platelets. Immunogold cytochemistry detected large amounts of PAI-1 antigen in the partially lysed platelet-fibrin thrombi. This PAI-1 appeared to be bound to the fibrin network rather than to the platelet surface itself. We conclude that the residual clots observed late in lysis represent platelet-associated fibrin to which platelet-released PAI-1 has bound, rendering it less susceptible to degradation.

Adult↗
PubMed1991

Inhibitory mechanisms of attention: locus, stability, and relationship with distractor interference effects.

This paper examines three properties of attentional inhibition mechanisms. First, previous research has suggested that the inhibitory mechanism of selective attention has a central locus between perception and action. We attempt to confirm the locus of this inhibition. Second, the processing of an unattended stimulus has been observed via the effects of the stimulus on a concurrent target (interference), and on a subsequent target (negative priming). The former effect demonstrates that distractors interfere with the processing of the target, and the latter negative priming effect implies that distractors are inhibited during selection. We demonstrate that these two measures of unattended processing can be dissociated. Third, we reveal that inhibition appears to be a stable mechanism of selection, in that effects do not decline after a large number of experimental trials.

Attention↗
PubMed1990

Coexistence of an intrauterine pregnancy with both an ectopic pregnancy and salpingitis in the right fallopian tube. A case report.

The current epidemic of pelvic inflammatory disease and recent advances in gynecologic techniques have resulted in a marked increase in the incidence of combined pregnancy. In the case reported on here the coexistence of an intrauterine pregnancy with acute salpingitis and an ectopic gestation in the same fallopian tube led to early diagnostic errors.

Adult↗
PubMed1986

Mitochondrial death in sepsis: a failed concept.

The concept of early selective mitochondrial injury has been proposed to explain the global metabolic dysfunction observed in the septic state. A two phase study was undertaken to test the validity of this hypothesis. In the initial phase, an endotoxin shock model was employed in the rat to delineate the function of skeletal muscle mitochondria. Mitochondrial function was determined polarimetrically, comparing state three and state four rates, respiratory control index (RCI) and ADP:O ratios. No significant alteration in these parameters was observed in the endotoxic state. Phase II of the study was designed to investigate mitochondrial function in a bacterial peritonitis rat model. Both liver and skeletal muscle mitochondrial function were determined to control for possible alterations in liver metabolism. Neither muscle nor liver mitochondria exhibited functional impairment during sepsis. We conclude from this study that neither endotoxemia nor peritonitis selectively "kills" mitochondria as previously suggested.

Animals↗
PubMed1986

Pneumatosis intestinalis in cystic fibrosis.

We retrospectively reviewed the clinical and radiographic findings in patients with pneumatosis intestinalis (PI), who were identified among 441 patients with cystic fibrosis. Since 1944, the age at onset and the incidence of PI have increased. Pneumomediastinum, pneumothorax, or pulmonary interstitial emphysema was found in 95% of patients with PI compared with 62% of patients without PI. The type, distribution, and severity of PI often changed with time. PI is correlated with the development of obstructive pulmonary disease, which facilitates air dissection into interstitial spaces. Dissection of air is often clinically silent and tends to be self-perpetuating.

Adolescent↗
PubMed1986

The grid radiograph. A simple technique for consistent high-resolution visualization of the hip.

The grid radiograph, a new technique for radiographic evaluation of total hip replacements, ensures reproducible positioning of the hip and the x-ray beam. When this method was used, the images of stable acetabular and femoral components on one radiograph could be superimposed perfectly on the images of these components on subsequent radiographs. Subtle shifts in the positions of the components, such as tilting of the femoral surface replacement, subsidence of the femoral component, or migration of the acetabular component, were detected. When used with high-contrast radiographic technique and film, the implant-bone interfaces were depicted better by this method than by others. Grid radiographs can be used for detailed prospective evaluation of total hip replacements and are of practical value in counseling patients about the probable durability of the replacement.

Acetabulum↗
PubMed1985

The effect of music, therapy, and relaxation on adrenal corticosteroids and the re-entrainment of circadian rhythms.

The purpose of this study was to measure the effects of music, progressive muscle relaxation (PMR), and guided imagery (GI) on the adrenal corticosteroids, or "stress hormones." Hypotheses were designed to evaluate the effect of a taped induction of music/PMR/GI on the mean level (1), circadian amplitude (2), and circadian re-entrainment with body temperature (3) of urinary corticosteroids. Urine collections and body temperature were recorded in shift-working nurses during three 4-5 day intervals over a 1-month period. The nurses listened to the tape on a daily basis, commencing after the first recording period. Results indicated that circadian amplitude decreased significantly (p = .007), and corticosteroid and temperature rhythms were significantly (p less than .01) more entrained during the tape conditions. The mean corticosteroid level also declined during tape listening, but nonsignificantly (p = .15). Because of the close relationship between corticosteroids and the immune system, these data suggest a relationship between music/relaxation techniques and physical health.

Circadian Rhythm↗
PubMed1985

Lack of association of A/NJ/76 (swine flu) vaccine and polymyositis.

There is no indication of an increase in the number of cases of polymyositis/dermatomyositis observed and reported among the 43.3 million civilians who received the A/NJ/76 (swine flu) vaccine from October 1 to December 16, 1976, in the United States. Among nearly 1 million Army and Navy personnel who received the vaccine, there was no increase in the incidence rate of polymyositis/dermatomyositis. Furthermore, there was no indication of an increase in the number of cases of polymyositis/dermatomyositis diagnosed at the Mayo Clinic, the Cleveland Clinic, the Cleveland Metropolitan Hospital or the Massachusetts General Hospital during or following the national immunization program in 1976.

Dermatomyositis↗
PubMed1984

Resistance trends of Neisseria gonorrhoeae in the Republic of Korea.

Penicillinase-producing Neisseria gonorrhoeae has increased in the Far East to the point that penicillin can no longer be recommended as the drug of choice, mandating a change to spectinomycin. As part of an ongoing surveillance of antibiotic susceptibilities, minimal inhibitory concentrations of penicillin, tetracycline, spectinomycin, trimethoprim-sulfamethoxazole, cefoxitin, ceftriaxone, cefotaxime, and moxalactam were determined. A disturbing, steady increase in resistance to spectinomycin was documented.

Anti-Bacterial Agents↗