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Biomedical subjects

S Johnson

Publications and source records attributed to S Johnson.

At least 253 records · Page 14Linked to original sources
PubMed1996

Coagulation changes during thoracoabdominal aneurysm repair.

PURPOSE: The cause of coagulopathic hemorrhage during thoracoabdominal aneurysm (TAA) repair has not been well defined in human studies. We investigated changes in the coagulation system associated with supraceliac versus infrarenal cross-clamping to address this critical issue. METHODS: Blood levels of fibrinogen, the prothrombin fragment F1.2, D-dimer, and factors II, V, VII, VIII, IX, X, XI, and XII were analyzed in 19 patients with TAAs and four patients with abdominal aortic aneurysms (AAAs) at: (A) induction; (B) 30 minutes into supraceliac (TAA) or infrarenal (AAA) clamping; (C) 30 minutes after release of supraceliac or infrarenal clamps; and (D) immediately after surgery. Preoperative and intraoperative variables, including but not limited to aneurysm type, pathologic findings, comorbid conditions, clamp times, volume and timing of blood products, and clinical outcome, were prospectively recorded. Significance was determined by analysis of variance, Student's t test, and univariate linear regression. RESULTS: Levels of fibrinogen and factors II, V, VIII, VIII, IX, X, XI, and XII decreased (p < 0.05) at time B versus time A and returned to near baseline by time D. D-dimer and F1.2 increased starting at time B and reached significance (p < 0.05) by time D. Data points were compared for the TAA and AAA groups. Although AAA groups demonstrated a trend to factor activity reduction and increased fibrinolysis, the effect was much less pronounced than in TAA and did not approach significance. No correlation of coagulation change with clamping time was present; however, visceral clamping times were all less than 65 minutes (mean, 44 minutes). Blood and factor replacement was initiated after time B. Univariate regression analysis of factor level versus total blood replacement demonstrated a significant (p < 0.04) correlation between the reduction in the levels of factors II, V, VII, VIII, X, and XII, and the increase in the level of D-dimer at time B and subsequent total blood replacement. CONCLUSIONS: Thoracoabdominal aneurysm repair is associated with a reduction in clotting factor activity and an increase in fibrinolytic function, which occurs after placement of the supraceliac clamp. Explanations include visceral ischemia or a greater and longer ischemic tissue burden as the likely cause of coagulation alterations. Total blood replacement during TAA procedures was correlated to the degree of factor reduction and fibrinolysis at the time of visceral cross-clamping. An aggressive approach to early blood component replacement and to coagulation monitoring could lessen blood loss during TAA repair and avoid potentially disastrous bleeding complications.

Aortic Aneurysm, Abdominal↗
PubMed1996

Morning report: a forum for reporting adverse drug reactions.

BACKGROUND: Most hospitals that monitor adverse drug reactions (ADRs) through reporting by nurses, pharmacists, medical record technicians, and quality improvement staff experience low rates of reporting. In teaching hospitals, inadequate orientation about the hospital activities, frequent changes in rotations between hospitals, and time commitments to educational pursuits may all undermine house staff's ability to perform ADR monitoring. The authors describe their experience since 1989 at the Department of Veterans Affairs Medical Center in Amarillo, Texas, in the use of verbal ADR reporting by physicians (mostly house staff) during the morning report in the medical service. ADR MONITORING PROGRAM: The morning report begins with a discussion of adverse outcomes of medications, usually from the previous 24 hours. The staff physicians use the opportunity to address the nature of the ADRs and the clinical circumstances leading up to them. Some ADR episodes require further peer review by a physician before being forwarded to the Pharmacy and Therapeutics Committee. EFFECT OF THE PROGRAM: Since the start of the ADR monitoring program in 1989, the number of self-reported ADRs in the medical service has increased over historical controls, even though no special training was given to house staff to detect ADRs. The surgical and psychiatric services, which did not hold morning reports, did not experience the same increase in ADR reports. CONCLUSIONS: The ADR monitoring program is notable for the simplicity of the reporting mechanism, the integration of the reporting into the regular work flow activities, the concurrent nature of the reporting, the educational opportunities, and the potential benefit for quality improvement of patient care.

Adverse Drug Reaction Reporting Systems↗
PubMed1996

Insight, psychosis and ethnicity: a case-note study.

Recent literature on insight has paid little attention to patients' social backgrounds and cultures. Discharge summaries from 357 patients with a psychotic illness were examined to investigate factors associated with insight. A highly significant association was found between British white ethnic origin and being thought by the admitting psychiatrist to have some insight. Possible explanations include: different ways of understanding mental illness in different cultures, greater stigma leading to greater denial of illness in some cultures, greater illness severity at admission in some ethnic groups and racial bias in psychiatrists' ratings.

Adolescent↗
PubMed1996

Emotionally focused marital intervention for couples with chronically ill children.

Couples with chronically ill children are at risk for experiencing marital stress. The present study was a randomized control trial that assessed the efficacy of emotionally focused therapy (EFT) in decreasing marital distress in this population of couples. Thirty-two couples with chronically ill children seen at a tertiary care pediatric hospital were randomly assigned to EFT or to a waitlist control group. EFT couples demonstrated significant decreases in marital distress at posttreatment and at a 5-month follow-up in comparison to controls. Clinical improvements in marital functioning following EFT were also demonstrated.

Adaptation, Psychological↗
PubMed1996

Repetitive relationship themes in waking narratives and dreams.

The aims of the study were to see whether the core conflictual relationship theme (CCRT) measure can be reliably applied to dreams and to evaluate the degree to which the main components of the CCRT are present in both dreams and waking narratives in psychotherapy. For 13 psychoanalytic cases, the reliability of the CCRT was found to be good. Dreams and narratives were found to contain significant degrees of similarity in their CCRT components and similar and high level of negativity in both dreams and waking narratives. The results support the concept of a central relationship pattern that can be expressed in common in both waking narratives and dreams.

Adult↗
PubMed1996

Protein-losing enteropathy is associated with Clostridium difficile diarrhea but not with asymptomatic colonization: a prospective, case-control study.

A prospective, case-control study was performed in which enteric protein loss and nutritional status were measured in patients with symptomatic and asymptomatic infections due to Clostridium difficile. Enteric protein loss, measured by elevated levels of fecal alpha1-antitrypsin, was detected in 14 of 20 cases and controls with diarrhea (9 of 10 cases with C. difficile-associated diarrhea and 5 of 10 age-matched control with diarrhea not associated with C. difficile) compared with none of 20 asymptomatic cases and controls (10 colonized cases and 10 noncolonized controls without diarrhea who were matched by age and clinical diagnosis) (P < .0001). Cases and controls with diarrhea had higher prognostic nutritional index values (P = 0.005) and lower levels of serum albumin, transferrin, and cholesterol than did the asymptomatic cases and controls. Decreased nutritional status, measured by increased prognostic nutritional index values, was associated with the presence of diarrhea but not with the presence of C. difficile. Protein-losing enteropathy was associated with C. difficile only in the presence of diarrhea, and we did not detect an increased risk of protein-losing enteropathy or malnutrition as a consequence of asymptomatic colonization with C difficile.

Aged↗
PubMed1996

Prolonged and preferential production of polymeric immunoglobulin A in response to Streptococcus pneumoniae capsular polysaccharides.

Streptococcus pneumoniae is an invasive mucosal pathogen for which host defense is dependent on capsular polysaccharide-specific antibody. Capsule-specific immunoglobulin G (IgG), IgM, and IgA are produced following pneumococcal vaccination and infection. Serum IgA has two molecular forms, polymeric and monomeric. These forms may modulate the avidity of antigen binding and evolve over time as the immune response matures. Therefore, we sequentially characterized the molecular forms of serum IgA to three serotypes of pneumococcal capsular polysaccharides (types 8, 12F, and 14) after pneumococcal vaccination and after natural infection with type 14 S. pneumoniae. Although typically the form of IgA in antigen-specific systemic responses to protein antigens is predominantly polymeric in sera of patients shortly after exposure and shifts to the monomeric form in sera obtained several weeks later, the form of IgA in response to each pneumococcal capsular polysaccharide remained predominantly polymeric 1 month after natural infection and up to I year following vaccination. In contrast, IgA to pneumococcal cell wall polysaccharide was both polymeric and monomeric. Moreover, the form of IgA in response to polyribosyl-ribitol-phosphate (PRP), the capsular polysaccharide of Haemophilus influenzae type b, was predominantly monomeric in the sera of 8 of 10 subjects tested 1 to 3 months after vaccination with either PRP alone or the diphtheria toxoid conjugate of PRP. We conclude that systemic responses to pneumococcal capsular polysaccharides are distinct in the production of predominantly polymeric IgA over time. The persistence of polymeric IgA may facilitate binding and clearance of pneumococci from the systemic circulation or reflect limited maturation of the immune response to pneumococcal capsular polysaccharides.

Adult↗
PubMed1996

Neutralizing antibodies to Escherichia coli Vero cytotoxin 1 and antibodies to O157 lipopolysaccharide in healthy farm family members and urban residents.

An enzyme-linked immunosorbent assay (ELISA) to detect antibodies to Escherichia coli O157 lipopolysaccharide (LPS) was developed with sera from 63 children with confirmed recent E. coli O157 infection and from 256 age-stratified urban controls. The median ELISA values for control and case sera were 0.05 (interquartile range, 0 to 0.20; mean +/- standard deviation [SD], 0.15 +/- 0.22) and 1.41 (interquartile range, 1.11 to 1.59; mean +/- SD, 1.41 +/- 0.53), respectively (P < 0.001). With a breakpoint of 0.59 (mean ELISA value of the control sera + 2 SDs), the assay had a sensitivity, specificity, and positive and negative predictive values of 95, 94, 80, and 98%, respectively, for recent E. coli O157 infection. The O157 LPS assay and Vero cytotoxin (VT) 1-neutralizing-antibody (NAb) assay were used to compare the relative frequencies of O157 LPS antibodies and VT1-NAbs in an age-stratified urban population from Toronto, Ontario, Canada, and in 216 healthy family members from dairy farm in southern Ontario. The frequency of O157 LPS antibodies was about threefold higher in dairy farm residents (12.5%) than in urban residents (4.7%) (P < 0.01). Similarly, the frequency of VT1-NAbs was about sixfold higher in dairy farm residents (42.0%) than in urban residents (7.7%) (P < 0.001). These findings are consistent with a greater level of exposure of dairy farm residents to VT-producing E. coli (VTEC) strains. The high rate of seropositivity to VT1 in farm residents probably reflects the booster effect of repeated VTEC exposures and argues against a sustained generalized immunosuppressive effect of VT1. Seroepidemiological studies may help in assessing the level of exposure of different populations to VTEC strains.

Adolescent↗
PubMed1996

Drug and alcohol problems among individuals with severe mental illness in south London.

BACKGROUND: High rates of comorbid alcohol and drug disorders have previously been found among individuals with severe mental illnesses such as schizophrenia and bipolar affective disorders. Clinical and social outcomes have been reported to be worse in this group and service costs greater than in individuals with severe mental illness only. These 'dual diagnosis' patients have mainly been investigated in the USA, and there has been very little research in Europe, where patterns of substance abuse may be different. METHOD: All patients with psychotic illnesses who had any contact with the mental health services in a geographically defined sector in South London over a specified period were studied. Individuals with problems related to alcohol or drugs were identified using standardised interviews with subjects and their keyworkers. Data on psychiatric service use during the previous 2 years were also obtained. RESULTS: One hundred and seventy-one subjects with psychotic illnesses were interviewed (response rate: 78.4%). The one-year prevalence rate for any substance problem was 36.3% (95% CI = 29.1-43.5), for alcohol problems it was 31.6% (95% CI = 24.6-38.5), and for drug problems 15.8% (95% CI = 10.3-21.3). Young male subjects were at higher risk of having substance problems. Patients with substance problems had spent almost twice as many days in hospital as those without such problems over the previous two years (difference = 26.3 days, 95% CI = 3.8-48.7). CONCLUSIONS: The prevalence of substance problems among people suffering from severe mental disorders is high, and seems to be associated with greater use of in-patient services. This is a significant clinical problem, with cost implications. Further investigation is needed for adequate service provision.

Adolescent↗
PubMed1996

Mental health, "burnout' and job satisfaction among hospital and community-based mental health staff.

BACKGROUND: Concerns have been expressed that staff burnout may make community mental health care difficult to sustain. This study compares stress and job satisfaction between community and hospital-based staff. METHOD: The GHQ-12, the Maslach Burnout Inventory and a job satisfaction measure were used to study 160 Inner London staff. RESULTS: Community staff scored significantly higher on the GHQ-12 and the "emotional exhaustion' component of the Maslach Burnout Inventory than hospital-based in-patient, day care or out-patient staff. Satisfaction did not vary significantly between settings. CONCLUSIONS: These results may be explained in several ways. Community work may be inherently more stressful than hospital work, or may currently be stressful because of inadequate resources, training or supervision. The results may also reflect widespread recent changes in community services or the specific effects of working in a deprived area.

Adult↗
PubMed1996

Oral cladribine as primary therapy for patients with B-cell chronic lymphocytic leukemia.

PURPOSE: Purine analogs have wide potential indications in the treatment of hematologic malignancies, but intravenous administration has been required. We previously established that the oral bioavailability of cladribine is 50%. Our aim was to evaluate the efficacy and toxicity of oral cladribine to previously untreated patients with chronic lymphocytic leukemia (CLL). PATIENTS AND METHODS: Sixty-three patients with symptomatic but previously untreated CLL received cladribine solution 10 mg/m2/d orally for 5 consecutive days in monthly courses. RESULTS: Complete remission (CR) was achieved in 24 patients (38%), and 23 patients (37%) had a partial response (PR). Most patients, including those in whom there was no remission (NR) achieved normal blood lymphocyte counts. Failure to meet response criteria was mostly due to thrombocytopenia. The median response duration was not reached at 2 years. The median survival time among 13 deceased patients was 322 days, whereas the median observation time of surviving patients is 760 days. The overall survival rate at 2 years is 82%. Response rate was associated with clinical stage. Grade III to IV infectious toxicity occurred in one third of patients. CONCLUSION: Orally administered cladribine is an effective and feasible therapy for CLL, and produces durable remissions in three quarters of the patients. However, significant toxicity may occur and further studies are required to assess long-term effects and quality-of-life aspects.

Administration, Oral↗
PubMed1996

Antenatal phenobarbital therapy and neonatal outcome. I: Effect on intracranial hemorrhage.

OBJECTIVE: To evaluate the effect of antenatal phenobarbital (PB) therapy on neonatal intracranial hemorrhage (ICH) in preterm infants. DESIGN: Prospective, randomized, controlled trial. SETTING: Single institution study. SUBJECTS AND INTERVENTIONS: Women in preterm labor ( < 35 weeks' gestation) were assigned to control and treatment groups. The treatment group received 10 mg/kg (maximum, 1000 mg) PB intravenously, followed by 100 mg orally daily, until delivery. Neonates did not receive PB after birth. Head sonograms were performed on days 3, 7, and 14 and at discharge. Hemorrhage was classified as mild, moderate, or severe by a single reader. OUTCOME MEASURES: Incidence of neonatal ICH in all infants, infants weighing less than 1250 g, and infants of multiple gestations. RESULTS: The study population comprised 110 women, 60 in the control group and 50 in the PB group. Neonates in the control group (n = 74, including 10 pairs of twins and 2 sets of triplets) were comparable to those in the treatment group (n = 62, including 7 pairs of twins, 1 set of triplets, and 1 set of quadruplets) regarding birth weight, gestational age, and other clinical risk factors for ICH. There was a trend for the incidence of any grade of hemorrhage to be lower in the PB group (22% [14 of 62]) compared with the control group (35% [26 of 74]). Moderate and severe hemorrhages were significantly lower in the PB group (1.6% [1 of 62]) compared with the control group (9.4% [7 of 74]). Among infants weighing less than 1250 g, overall ICH was lower in the PB group (23% [6 of 26]) compared with the control group (51% [18 of 35]). Among multiple-gestation infants, overall ICH was 4.7% (1 of 21) in the PB group, compared with 31% (8 of 26) in the control group. CONCLUSIONS: Antenatal PB therapy results in a significant decrease in moderate and severe ICH in infants born at less than 35 weeks' gestation. Antenatal PB therapy also resulted in a decrease in the incidence of all grades of ICH in infants weighing less than 1250 g and infants born of multiple gestations.

Administration, Oral↗
PubMed1996

Evaluation of two treatment regimens of pralidoxime (1 gm single bolus dose vs 12 gm infusion) in the management of organophosphorus poisoning.

Organophosphorus (OP) poisoning is most frequently encountered among our community. Treatment of poisoning is primarily aimed at reversing the effects of the compound by administration of atropine. Oximes have been shown to be efficacious in case reports. The dose of this drug in these reports varies from 1 gm which is a very low dose and physiologically no dose, to doses upto 16 gm. This is also a very expensive imported drug which causes the nation considerable loss of foreign exchange. We report our experience with the use of two treatment regimens of Pralidoxime (P2AM) in the management of patients with OP poisoning in a prospective trial. Seventy-two adult patients presenting to a large university affiliated teaching institution with a history of consumption of OP compounds and requiring intensive care were entered into the trial. Patients were randomized using a block randomisation to receive either a single bolus dose of 1 gm P2AM at admission (Low dose group) followed by placebo infusion over the next 4 days or a single placebo bolus at admission followed by P2AM 12 gm as a continuous infusion over the next 4 days. Outcome measures analyzed were mortality, duration of ICU stay, need for ventilation and duration of ventilation, time to recovery of consciousness, development of intermediate syndrome and infections. A higher prevalence of intermediate syndrome (p = 0.08) was observed in the high dose group. Ventilatory requirement was also more in the high dose group (p = 0.09). Since this was an equivalence study designed to show that the low dose was as effective as the high dose, these results attain greater significance as the low dose group fared better than the high dose group, even though the pre-test hypothesis was in the reverse direction. Subgroup analysis of patients who received at least 1 gm of P2AM within 12 hours of ingestion of the OP poison with those who received P2AM after 12 hours, showed that there was a significant reduction of intermediate syndrome (p = 0.05) but no significant difference was noted in number ventilated. High dose P2AM infusion has no role in the routine management of patients with OP poisoning. These results also suggest that the time of administration of P2AM after the ingestion of the poison mabe a crucial factor which determines response to therapy. A prospective double blind placebo controlled trial is now justified in the light of the above findings.

Adult↗
PubMed1995

Direct gas chromatographic determination of dechloroethylcyclophosphamide following microsomal incubation of cyclophosphamide.

A method for the sensitive determination of dechloroethylcylclophosphamide (3-DCl) in microsomal incubation mixtures was developed. 3-DCl, a side-chain oxidation product of cyclophosphamide (CP), was isolated by extraction with acetic acid ethyl ester following solid-phase extraction on C8 cartridges. Quantification of the metabolite was performed by direct capillary gas chromatography with a nitrogen-phosphorus detector without prior derivatization. The method showed good sensitivity and reproducibility with a detection limit of 1 ng/ml and a limit of quantification of 5 ng/ml. The suitability of the method is shown for the quantification of 3-DCl following incubation of CP with human liver microsomes.

Animals↗
PubMed1995

FemA of Staphylococcus aureus: isolation and immunodetection.

FemA, a cytoplasmic protein necessary for the expression of methicillin resistance in Staphylococcus aureus and also involved in the biosynthesis of staphylococcal cell walls, was detected and quantified in several S. aureus strains under different growth conditions by Western immunoblot. Two types of antigens were used for the production of polyclonal antibodies against FemA: (i) a synthetic peptide comprising 14 amino acids of its C-terminal sequence; and (ii) FemA isolated by preparative gel electrophoresis and electroelution from an overproducing staphylococcal strain. Immunodetection revealed that all investigated strains, either methicillin-resistant or susceptible, expressed FemA during the exponential growth phase in varying amounts. In the stationary phase, the FemA content was diminished. Strains in which femA was inactivated by insertion of Tn551 into the control region of the femAB operon still expressed about 10% of the protein compared to their parent strains. Tn551 insertion in the middle of the femB gene did not affect the FemA expression. In 40 methicillin-susceptible and 6 resistant clinical isolates of S. aureus, the FemA content or its affinity to the antibodies was reduced compared to laboratory parent strains. In susceptible strains, an additional protein of higher molecular weight, present in large quantities, was also able to bind the FemA antibodies. Such a protein was also present in methicillin-resistant isolates, although it was not as pronounced as in the susceptible strains.

Antibodies, Bacterial↗