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Biomedical subjects

L Black

Publications and source records attributed to L Black.

At least 19 recordsLinked to original sources

Myocardial reperfusion injury: the critical challenge.

Oxygen-free radical production and reperfusion injury are complex mechanisms. New and improved methods for maximizing the benefits of reperfusion while minimizing reperfusion injury are on the horizon in the 1990s. Critical care nurses play a crucial role in the assessment, planning, and intervention of patients experiencing the deleterious effects of free radicals and reperfusion injury. Thus, a sound knowledge base in the pathophysiology of reperfusion injury, the detrimental effects of free radicals, and the potential benefits of free-radical scavengers is essential.

Free Radical Scavengers

The nuts and bolts of organizing and initiating a pediatric transport team. The Sutter Memorial experience.

Specialized interfacility transport teams are capable of delivering critical care medicine to the patient at the referring hospital and while en route to the tertiary care center. To do so effectively, however, requires adequate financial and human resources; management of equipment, supplies and personnel; ongoing education for transport team members; and an aggressive quality assurance program. Team members and team management should always be prepared for worst-case scenarios, and develop a method for problem resolution as troublesome issues arise. The ultimate goal of serving the needs of the critically ill child can be consistently met only if there is a high level of commitment of all involved--from the hospital administrator and medical director to the transport coordinator and team members.

California

Quality monitor implementation for standards of care of the mechanically ventilated patient.

Each critical care unit has a responsibility to develop a quality assurance process to evaluate nursing practice. Staff members at Shawnee Mission Medical Center (SMMC) developed a protocol, based on the Marker Model, to establish standards of care related to care of the patient requiring mechanical ventilation. The quality assurance process used to monitor implementation of the standards is described.

Critical Care

Turn it around: short-term management for aggression and anger.

1. Although nurses are at considerable risk for assaults, there are few practical and specific guidelines for controlling anger and aggression. 2. A training course was developed to give staff the necessary skills and knowledge to cope with clients who have the potential to become angry and assaultive, or those who have already become violent. 3. Participants in the training course felt more confident in managing potentially violent situations, and they reported relying on methods to de-escalate the situation to halt a sequence that would ultimately lead to violence.

Aggression

Reperfusion and reperfusion injury in acute myocardial infarction.

Recognition of the clinical markers of reperfusion and comprehension of the effects of reperfusion injury in acute myocardial infarction provide a unique challenge for today's critical care nurse. In this article we will explore the processes of reperfusion injury. A review of relevant literature and presentation of a clinical case study and care plan will enable the critical care nurse to construct a larger knowledge base and assist in the nursing management of patients with acute myocardial infarction. Evaluation and treatment of reperfusion and reperfusion injury remains under investigation, but through the skills of assessment, planning, and intervention the critical care nurse can coordinate prompt and appropriate care to the patient with an acute myocardial infarction.

Critical Care

Anger control.

Anger is a poorly understood but very common emotion. When it is misdirected or uncontrolled it becomes dangerous. An analysis of anger and a treatment paradigm is presented, and we outline a research project in which we are using the approach with a group of mentally handicapped adults.

Aggression

Effects of birth weight and ethnicity on incidence of sudden infant death syndrome.

Sudden infant death syndrome occurs with increased frequency in low birth weight infants and in black infants. The degree to which the higher LBW rate among blacks might explain this higher SIDS rate is unknown. To address this question, we analyzed the 1233 SIDS deaths that occurred among 252,376 neonatal survivors in Cook County from 1975 to 1980, using computer-coded matched infant birth and death records. Birth weight and ethnic group were identified. The overall SIDS rates in blacks, Hispanics, and whites were 5.1, 1.2, and 1.3/1000 neonatal survivors, respectively. Within each ethnic group, the SIDS rates increased progressively with decreasing birth weight. Within the less than or equal to 1500 gm birth weight groups, the SIDS rates were 16.4, 3.9, and 5.5/1000 neonatal survivors in blacks, Hispanics, and whites. Using direct standardization, we found that 27% of the SIDS rate disparity between blacks and whites could be explained by the higher LBW rate in blacks (14% vs 6% in whites). The good outcomes in both LBW and SIDS rates for the Hispanic population were unexpected because, like blacks, Hispanics are socioeconomically disadvantaged. Findings for this group suggest that the remaining 73% of the increased SIDS rate in blacks cannot be attributed in a straightforward manner to differences in income or educational attainment.

Black or African American

Humoral response of pregnant sows to foot and mouth disease vaccination.

Four groups of sows were inoculated, either once or twice, with O1BFS 1860 foot and mouth disease oil-emulsion vaccine during pregnancy and samples of serum, for analysis, were collected at intervals for greater than 300 days. The pregnant sows responded well to vaccination regardless of their state of gestation. Single vaccination produced protective levels of antibody (greater than 1.53 log10SN50) in 3 out of 4 sows while double vaccination produced protective levels in all 6 sows tested. Anti-FMD IgM antibodies could be detected for 40-60 days after vaccination or revaccination. Anti-FMD IgG antibodies appeared within 10 days of vaccination and persisted, in each sow, for the duration of the study. The anti-FMD IgA response observed was less easy to characterize due to significant animal to animal variation. Although there was no evidence of a fall in the neutralizing antibody titres over one year post vaccination the anti-FMD IgG antibody population did show signs of a change in its heterogeneity and avidity.

Animals

Separation and characterization of potential allergens from cultured baby hamster kidney cells.

Residual cellular material present in foot-and-mouth disease (FMD) vaccines has been implicated as a possible cause of hypersensitivity in cattle. This study was designed to identify and characterize the potentially allergenic components involved. After fractionating baby hamster kidney (BHK) cell lysate, by preparative electrofocusing and gel filtration chromatography, the eluates which were potentially allergenic for cattle were identified by passive cutaneous anaphylaxis (PCA) and PCA-inhibition methods. The potential allergen identified had a molecular weight of approximately 43 000 daltons, sedimentation coefficient of 3.65 S20 and isoelectric points between pH 5.37 and 6.25. Based on these results an immunogenic FMD vaccine was produced which failed to provoke clinical sensitization after repeated inoculations. This information should enable manufacturers to identify, monitor and subsequently control the levels of any such potentially allergenic material present in current vaccines produced using BHK cells.

Allergens

Foot-and-mouth disease vaccination: a multifactorial study of the influence of antigen dose and potentially competitive immunogens on the response of cattle of different ages.

Groups of 68 and 66 cattle aged 12 and 24 months respectively were each subdivided into 16 groups and inoculated with foot-and-mouth disease vaccines containing O1 Campos, A24 Cruzeiro and C3 Pando virus strains. The 140S antigen mass of the O1 and A24 valencies was varied while that of C3 was held constant. Multifactorial comparisons between the 21 day serum neutralising antibody titres showed that over most of the range there was a linear log dose response relationship. Doubling the antigen dose increased the serum antibody titres against both A24 Cruzeiro and O1 Campos by approximately 0.15 log10. The A24 antigen was about 30 times more immunogenic than the O1 with C3 intermediate between the two. At high antigen doses the responses flattened but the level at which this occurred depended on the immunogen administered. No difference could be demonstrated between the responses of 12- and 24-month-old cattle and there was no evidence of competitive inhibition or enhancement between the virus strains included in the vaccines.

Aging

Response of young pigs to foot-and-mouth disease oil emulsion vaccination in the presence and absence of maternally derived neutralising antibodies.

Serum samples and bodyweights were taken at regular intervals for six to seven months from piglets, born to foot-and-mouth disease (FMD) vaccinated or unvaccinated sows, which had been vaccinated at one, two, four or eight weeks old. Young pigs, devoid of maternally derived antibodies (MDA), were capable of responding to FMD vaccination at one week old, with no deleterious effects on their growth rate. However, their immunity to experimental infection at six to seven months old was poor (33.3 per cent). Vaccination of four or eight-week-old piglets, born to unvaccinated sows, protected 87.5 per cent from a similar challenge. In piglets, born to FMD vaccinated sows, the MDA had a suppressive effect on the early vaccination response. This suppression, which was affected by the titre of MDA present in the piglets at the time of vaccination, was complete in one-, two- and four-week-old piglets and partial in eight-week-old piglets. Furthermore, none of these piglets were immune to experimental infection at six to seven months old.

Aging

Densitometry and microchromatography compared for determination of the hemoglobin C and A2 proportions in hemoglobin C and hemoglobin SC disease and in hemoglobin C trait.

Using both densitometry and anion-exchange microchromatography, we measured hemoglobin C (Hb C) and Hb A2 proportions in 11 patients, eight of whom had Hb AC, two Hb SC, and one Hb CC. For one patient with Hb SC, we made the determinations before and after a transfusion. The mean (and SD) for the sum of Hb C + Hb A2 by densitometry and anion-exchange microchromatography for the nine patients with Hb AC and Hb CC were 45 (18) and 40 (18)%, respectively (p greater than 0.1, r = 0.98); for the three determinations involving the two Hb SC patients, the respective proportions were 40 (9.9) and 38 (6.6)% (r = 0.88). Electrophoretic analysis of microchromatographic eluates from the Hb AC and Hb CC patients showed that 6% of the absorbance of the late high-ionic-strength eluate was due to Hb C, which was responsible for the statistically insignificant difference between densitometric and chromatographic values for Hb C + A2 values. Electrophoresis on cellulose acetate of concentrated eluates of the Hb C + A2 fraction from the two Hb SC patients revealed no contamination by Hb S. Evidently, microchromatography can be used to determine Hb C + A2 in patients with Hb C or Hb SC disease or Hb C trait.

Anemia, Sickle Cell

The 45-kb unit of major urinary protein gene organization is a gigantic imperfect palindrome.

The multigene family which codes for the mouse major urinary proteins consists of about 35 genes. Most of these are members of two distinct groups, group 1 and group 2. The group 1 and group 2 genes are organized in head-to-head pairs within 12 to 15 remarkably uniform chromosomal units or domains about 45 kilobase pairs (kb) in size. The 45-kb units are located on chromosome 4, and many of them are adjacent to each other. We propose that the 45-kb unit is a unit both of organization and of evolutionary change. In this study the homologies within the unit were observed by examining, in an electron microscope, heteroduplex and foldback structures made from cloned major urinary protein genes. These show that the 45-kb unit is a gigantic imperfect palindrome. Each arm of the palindrome contains two regions of inverted symmetry of 9.5 and 4.5 kb separated by a 3-kb nonsymmetrical region. We argue that the nonsymmetrical regions arose by a series of deletion events in the two arms of the palindrome. The center of the 45-kb unit is an 8-kb sequence without inverted symmetry flanked by the 9.5-kb regions, which contain the 4-kb genes and their immediate 5' and 3' flanking regions. The junction between adjacent 45-kb units is a 2- to 4-kb sequence without inverted symmetry flanked by the 4.5-kb regions. Some of the 45-kb units are arranged as direct tandem repeats. Others appear to be in inverted orientation with respect to a neighboring unit. Cloned major urinary protein genes show few incidences of the repetitive elements B1, B2, R, and MIF. Two elements, a B1 and an R, may be a constant feature of the 45-kb units. If so, in those cases in which the units are in tandem array, both of these elements will occur with a 45-kb periodicity. A comparison of corresponding parts of different 45-kb units shows that they differ because of a number of deletion or insertion events, particularly in the regions 3' to the genes.

Animals

Guinea pig protection test as indicator of potency of oil emulsion foot-and-mouth disease vaccines.

A vaccine potency test is described involving virus challenge to six groups of 10 guinea pigs at five weeks after vaccination. Sixteen oil emulsion foot-and-mouth disease vaccines were so tested and nine retested after storage at 4 degrees C for up to 28.3 months. The results were compared with those of the routinely used oil emulsion vaccine potency test (protection afforded to eight pigs challenged 21 days after vaccination). When guinea pig estimates of 3 log2 PD50 or more were obtained, then, with one exception, the batches protected all or almost all pigs from challenge, but when the guinea pig estimates were less than 1 log2 PD50, the vaccines failed to protect five out of eight pigs. The sensitivity and reproducibility of the guinea pig method, established by repeated tests on two vaccine batches, seemed acceptable. The results suggested that guinea pig estimates might provide a suitable substitute for pig challenge potency tests because they reflected the potency of the vaccines, were likely to involve smaller standard errors and caused less discomfort to animals.

Animals