The linearity of the volume/pressure response during intracranial pressure "reserve" testing.

The intracranial pressure "reserve" test seems to be the most reliable method of determining when the brain''s natural mechanisms for pressure compensation for added intracranial volume have been compromised or exhausted. The test employs a timed sequence of intracranial fluid injections, but as a safety precaution injections are discontinued if intracranial pressure remains elevated more than 10 Torr over baseline. In this case, a linear extrapolation is then calculated to determine the elevation which might have been achieved by a full series of injections. However, this linear extrapolation has been criticised on the expectation that an exponential response should be expected. A series of experimental observations in dogs and baboons and a review of clinical records in humans have been made to determine the observed slope of increase following aliquot injection during performance of the intracranial pressure reserve test. In these species the observed response was actually linear in shape rather than exponential. This held true even for different initial baseline values and with different volumes of "lesion" balloon inflations in experimental animals. A theoretic explanation is proposed.     

Evolving a blueprint for certification: the responsibilities and knowledge comprising American professional oncology nursing practice.

Ensuring adequate content validity of a certification examination is a major concern in the development and administration of a test. To establish content validity of the Oncology Nursing Certification Corporation (ONCC) certification exam, a job analysis study was conducted to provide empirical data about the responsibilities and knowledge areas required for practice at the level of the newly certified oncology nurse. The study involved The Profession of Oncology Nursing: An Inventory of Responsibilities and Knowledge (IRKPON), a questionnaire that was developed based on a review of the literature, professional practice information, interviews with oncology nurses, the original ONCC certification exam table of specifications, and evaluations undertaken by two advisory committees. The IRKPON consisted of three parts: 56 responsibilities clustered into eight job dimensions, 217 knowledge areas grouped into seven knowledge dimensions, and demographic information. The IRKPON was sent to a stratified random sample of 3,000 oncology nurses in the United States, who were asked to rate both the responsibilities and knowledge areas by level of importance. The 1,297 (43%) responding nurses rated 45 of 56 responsibilities (80.4%) as "very important" and 8 of 56 responsibilities (14.3%) as "extremely important"; they also rated 163 of 217 knowledge areas (75.1%) as "very important" and 41 of 217 knowledge areas (18.9%) as "extremely important." These findings identified the specific responsibilities most important to the oncology nurse role at the level of the newly certified nurse, as well as the knowledge areas necessary for competent performance. Subsequent ONCC certification examinations were modified; the test blueprint that guides the construction of the examination was revised, and the passing score was adjusted.     

Screening for complement deficiency in bacterial meningitis

Seventy-seven children with bacterial meningitis were screened for complement deficiency. Both the classical and the alternate pathways were normal in 75 patients. Transiently reduced total haemolytic activity of the classical pathway was documented in a boy with meningococcal meningitis. Total haemolytic activity of both the classical and the alternate pathways were reduced in another patient with pneumococcal meningitis: individual complement components determination indicated predominant activation of the alternate pathway.     

Identification of differentially expressed genes in aflatoxin B1- treated cultured primary rat hepatocytes and Fischer 344 rats

Aflatoxin B1 (AFB1), a mutagen and hepatocarcinogen in rats and humans, is a contaminant of the human food supply, particularly in parts of Africa and Asia. AFB1-induced changes in gene expression may play a part in the development of the toxic, immunosuppressive and carcinogenic properties of this fungal metabolite. An understanding of the-role of AFB1 in modulating gene regulation should provide insight regarding mechanisms of AFB1-induced carcinogenesis. We used three PCR- based subtractive techniques to identify AFB1-responsive genes in cultured primary rat hepatocyte RNA: differential display PCR (DD-PCR), representational difference analysis (RDA) and suppression subtractive hybridization (SSH). Each of the three techniques identified AFB1- responsive genes, although no individual cDNA was isolated by more than one technique. Nine cDNAs isolated using DD-PCR, RDA or SSH were found to represent eight genes that are differentially expressed as a result of AFB1 exposure. Genes whose mRNA levels were increased in cultured primary rat hepatocytes after AFB1 treatment were corticosteroid binding globulin (CBG), cytochrome P450 4F1 (CYP4F1), alpha-2 microglobulin, C4b-binding protein (C4BP), serum amyloid A-2 and glutathione S-transferase Yb2 (GST). Transferrin and a small CYP3A-like cDNA had reduced mRNA levels after AFB1 exposure. Full-length CYP3A mRNA levels were increased. When liver RNA from AFB1-treated male F344 rats was evaluated for transferrin, CBG, GST, CYP3A and CYP4F1 expression, a decrease in transferrin mRNA and an increase in CBG, GST, CYP3A and CYP4F1 mRNA levels was also seen. Analysis of the potential function of these genes in maintaining cellular homeostasis suggests that their differential expression could contribute to the toxicity associated with AFB1 exposure.      

High-dose chemotherapy followed by reinfusion of selected CD34+ peripheral blood cells in patients with poor-prognosis breast cancer: a randomized multicentre study.

Seventy-one patients with poor-prognosis breast cancer were enrolled after informed consent in a multicentre randomized study to evaluate the use of selected peripheral blood CD34+ cells to support haematopoietic recovery following high-dose chemotherapy. Patients who responded to conventional chemotherapy were mobilized with chemotherapy (mainly high-dose cyclophosphamide) and/or recombinant human granulocyte colony-stimulating factor (rhG-CSF). Patients who reached the threshold of 20 CD34+ cells per microl of peripheral blood underwent apheresis and were randomized at that time to receive either unmanipulated mobilized blood cells or selected CD34+ cells. For patients in the study arm, CD34+ cells were selected from aphereses using the Isolex300 device. Fifteen patients failed to mobilize peripheral blood progenitors and nine other patients were excluded for various reasons. Forty-seven eligible patients were randomized into two comparable groups. CD34+ cells were selected from aphereses in the study group. Haematopoietic recovery occurred at similar times in both groups. No side-effect related to the infusion of selected cells was observed. The frequency of epithelial tumour cells in aphereses was low (8 out of 42 evaluated patients), as determined by immunocytochemistry. We conclude that selected CD34+ cells safely support haematopoietic recovery following high-dose chemotherapy in patients with poor-prognosis breast cancer.     

Menstrual, psychosexual, psychological and somatic sequelae following postpartum sterilisation.

This study was designed to investigate the menstrual, psychosexual, psychological and somatic sequelae in a group of women who may be more prone to express regret following sterilisation. They were at a younger age, and all underwent postpartum sterilisation. The follow-up was conducted by a questionnaire between 6 months and 5 years following the procedure. Data were available from 242 patients with 76.8% before age 30, and 23.2% age 30 or older. Of all the patients, 21.9% regretted their choice of sterilisation. About one-third had various menstrual cycle disturbances. In general, patients rated their sex life more enjoyable in many aspects. The two most common psychological symptoms were irritability, nervousness and depression. The common somatic symptoms were pelvic/ abdominal pain, backache and tiredness. A complete assessment of the patient's postoperative condition, including menstrual cycle history, sexual history, psychological and somatic complaints if any, is warranted during presterilisation counselling in addition to a routine informed consent. This is especially important for those patients who are known to be more prone to express regret following the procedure.     

Survival and functional outcome after prolonged intensive care unit stay

OBJECTIVE: To examine the functional outcome and costs of a prolonged illness requiring a stay in the surgical intensive care unit (SICU) of 7 of more days. SUMMARY BACKGROUND DATA: The long-term benefits and costs after a prolonged SICU stay have not been well studied. METHODS: All patients with an SICU length of stay of 7 or more days from July 1, 1996, to June 30, 1997, were enrolled. One hundred twenty-eight patients met the entry criteria, and mortality status was known in 127. Functional outcome was determined at baseline and at 1, 3, 6, and 12 months using the Sickness Impact Profile score, which ranges from 0 to 100, with a score of 30 being severely disabled. Hospital costs for the index admission and for all readmissions to Johns Hopkins Hospital were obtained. All data are reported as median values. RESULTS: For the index admission, age was 57 and APACHE II score was 23. The initial length of stay in the ICU was 11 days; the hospital length of stay was 31 days. The Sickness Impact Profile score was 20.2 at baseline, 42.9 at 1 month, 36.2 at 3 months, and 20.3 at 6 months, and was lower than baseline at 1 year. The actual 1-year survival rate was 45.3%. The index admission median cost was $85,806, with 65 total subsequent admissions to this facility. The cost for a single 1-year survivor was $282,618 (1996). CONCLUSIONS: An acute surgical illness that results in a prolonged SICU stay has a substantial in-hospital death rate and is costly, but the functional outcome from both a physical and physiologic standpoint is compatible with a good quality of life.     

Comparison of intraocular irrigating solutions in pars plana vitrectomy

A prospective, randomized, masked clinical study was conducted to examine the effects of pars plana vitrectomy on the corneal endothelium comparing Balanced Salt Solution (BSS) to BSS-Plus as an intraocular irrigating solution. Seventy-one patients were followed for at least six months. A significant 6.9% decrease in endothelial cell density was observed among all patients at six months postoperatively, compared to preoperative values, using the contralateral eye as a control. However, no significant difference in endothelial cell loss was found between BSS and BSS-Plus eyes. Both aphakic eyes and those undergoing lensectomy (with vitrectomy) showed a significantly greater reduction of endothelial cell density at six months compared to phakic eyes. No significant difference in corneal thickness was observed at six months postoperatively compared to preoperative values. For the one-year duration of our study BSS was as efficacious in preserving the integrity of the corneal endothelium as was BSS-Plus.