Losing the plot: narrative construction and longitudinal childbirth research

This article seeks to explore the ways in which theories of narrative might be significant in the study of childbearing. The event of childbirth and the process of women becoming mothers have major significance for individual biographies and are publicly defined. The medicalization of childbearing and the placing of a natural event into a pathological illness model has repercussions for the ways in which women experience and make sense of the event. The complex interweaving of public and lay narratives that surround this period of transition can lead to bafflement and the eventual construction of personal counternarratives. The context in which narratives are managed is explored.

d-band quantum well states

Observations of d-band quantum well states are made for atomically uniform Ag films on Fe(100) using angle-resolved photoemission. For increasing film thicknesses, quantum well peaks within the small 4d bandwidth multiply rapidly and merge into a bulklike spectrum at approximately 25 monolayers. An analysis of the peak positions yields a highly accurate bulk band structure of Ag. A very narrow d-band peak width (13 meV) is observed at the band top.

Transcriptional control of the neuronal nicotinic acetylcholine receptor gene cluster by the beta43' enhancer, Sp1, SCIP and ETS transcription factors

Receptors assembled from the products of a neuronal beta4alpha3alpha5 NAChR gene cluster depend on these genes being coordinately regulated in particular populations of neurons. Little is known, however, about the transcriptional mechanisms that are likely to underlie their co-expression in correct neuronal cell types. We have identified several regulatory elements and transcription factors that influence transcription of the alpha3 and beta4 genes. The promoters of these genes appear to contain a common cis element that binds Sp1 transcription factors. They can be activated by the POU-domain factor SCIP and activation does not require SCIP binding sites. Between these two promoters is a cell type specific enhancer called beta43'. This enhancer has little activity in non-neuronal cells and is preferentially active in particular populations of central neurons. The clustered genes are potential targets of ETS factors as the ETS domain factor, Pet-1 can activate beta43'-dependent transcription. The neuron-selective properties of beta43' and its location suggest that it is a component of the cis regulatory information required to control expression of the beta4 and alpha3 genes in specific populations of neurons.

Investigating the role of Ca2+-binding site IV in barnacle troponin C

Two genetically engineered, recombinant versions of native barnacle troponin C (TnC) (BTnC,) were created from the bacterially expressed, recombinant, wild-type BTnC (BTnCWT) to investigate the role of the Ca(2+)-specific sites in force regulation. The mutant BTnC4- contains a single amino acid mutation in site IV which results in the inactivation of site IV Ca2+ binding; the mutant BTnCTrunc lacks the last II amino acids of the C-terminal, and hence most of site IV. Both mutant proteins, which retain an active site II, bind to native TnC-depleted myofibrillar bundles and restore approximately 40% of the tension-generating capacity, about half that seen with purified native BTnC1 or BTnC2. This observation implies that the Mg(2+)-dependent interaction with troponin I (TnI) is at a location on TnC other than the C-terminal Ca(2+)-binding sites of BTnC2. Replacement with BTnCTrunc increases the sensitivity of the myofibrillar bundle to changes in ionic strength. Decreasing the ionic strength from 0.15 to 0.075 M increased force by 34%, a value much greater that the 8% increase seen in control bundles or bundles substituted with BTnC4-. These findings implicate TnC in determining this fibre characteristic, although this cannot be simply due to the alteration in the numbers of Ca2+ ions bound by the troponin complex since both BTnC4- and BTnCTrunc bind only 1 mol Ca2+/mol protein.

Injury prevention and emergency medical services for children in a managed care environment

Each year, 1 in 5 US children receives medical care as a result of injury. Injuries are the leading cause of medical spending for children ages 5 to 21 years, accounting for more than 20% of hospital admissions and days spent in the hospital. Pediatric injuries become an important issue for managed care organizations because of concern for member safety and increasing medical costs related to treatment. Because effective prevention decreases health care consumption, injury prevention often costs less than treating injuries. Simple devices, such as bicycle helmets, smoke detectors, and child safety seats, help keep children safe and save money. Appropriate emergency care at the scene of an injury, poison control centers that dispense expert advice over the telephone, and triaged regional trauma systems improve the outcome and save money at the same time. This article continues the white paper series by the Emergency Medical Services for Children Managed Care Task Force.

Eye-wall resection

PURPOSE

To review the ocular retention rates, visual results, and metastases in uveal tumors managed with eye-wall resection techniques.

METHODS

This was a retrospective analysis of uveal tumors selected for eye-wall resection with the surgical procedures performed by a single surgeon. All enucleation specimens were reviewed by one author. Both parametric and non-parametric analysis of data was performed.

RESULTS

A total of 132 eyes were scheduled for eye-wall resection surgery. Mean patient age was 52 years (range, 11 to 86 years). Tumors involved the iris alone in 17 cases, the iris-ciliary body in 53, the ciliary body alone in 16, and the choroid (ciliochoroidal, iris-ciliary body-choroid, or choroid) in 46 cases. A total of 114 eyes harbored melanomas; tumors located more posteriorly were more likely to have epithelioid cells (P < .05). Mean follow-up was 6 years. Mean number of clock hours in iris and iris-ciliary body tumors was 3.5. In tumors that involved the choroid, the mean largest diameter was 12.6 mm and the mean thickness was 8.2 mm. Ninety-three (70%) of 132 eyes were retained. Histologic assessment of surgical margins did not correlate with either evidence of tumor in enucleated eyes or metastatic disease. Surgical margins of tumors located more anteriorly were more likely to be clear on histologic evaluation (P < .05). Approximately 56% of retained eyes had a final visual acuity of 20/40 or better; visual results were significantly better in tumors located more anteriorly (P < .05). All retained eyes with iris tumors had a final visual acuity of 20/40 or better. In tumors that involved the choroid, 8 of 25 retained eyes kept visual acuity of 20/40 or better. Metastases developed in 8 patients; all metastatic events developed in patients with tumors that involved the choroid, and 7 of 8 were mixed cell melanomas.

CONCLUSIONS

Seventy percent of eyes were retained, and 56% of these had a final visual acuity of 20/40 or better. Only 7% of patients with uveal melanoma developed metastatic disease (mean follow-up, 6 years). Survival did not appear to be compromised with eye-wall resection, and in very thick melanomas located more posteriorly, ocular retention and visual results appeared to be better than that attained with radiation alone.

An evaluation of WHA resolution 45.5: health human resource implications

The World Health Assembly approved resolution WHA45.5 in 1992. This paper reports the findings of an evaluation of the implementation of this resolution using a survey technique. A total of 150 WHO Member States responded, for a 79% response rate. Findings suggest that the greatest strides worldwide have been made in education. While the data show that progress has been made at the country level, far more action is needed to strengthen nursing and midwifery if these cost-effective resources are to play a decisive role in improving the extent and quality of services, especially as delivered to people in the greatest need.

Investigation of a genetically engineered mutant of barnacle troponin C containing a central helix deletion

To examine the importance of the central alpha-helix of troponin C (TnC) we have bacterially expressed one of the isoforms of barnacle TnC (BTnC2), BTnCWT, but without the aspartate residue at position 80 in the central helix (BTnC80-). This manipulation is expected to produce an approximately 100 degrees axial rotation of the C-domain with respect to the N-domain, and a net charge change of -1. BTnC80- mutant was able to restore force to TnC-depleted skinned barnacle myofibrillar bundles to a greater extent than wild-type protein (approximately = 170%). Competition experiments between BTnC80- and BTnC2-4-, a mutant lacking both of the calcium-specific sites (sites II and IV), shows that deletion of a single amino acid in the central helix results in a protein with increased affinity for the thin filament and one that is bound preferentially compared to BTnC2-4- when at equimolar concentrations.

Emotional and behavioural problems and trauma exposure of school-age Palestinian children in Gaza: some preliminary findings

An international research team was established to design and implement a community-based, cross-section epidemiological survey of 669 school-age Palestinian children and their families living in the Gaza Strip. Several psychometric instruments were utilized for measuring mental health outcomes, including the Ontario Child Health Scale (OCHS) for measuring childhood emotional and behavioural problems, and the Child Post-traumatic Stress Reaction Index (CPTSRI) to measure post-traumatic stress disorder (PTSD). Lifetime trauma exposure was assessed by using the Health Reach Modified War Questionnaire. It was found that children and adolescents from age six to 16 have high prevalence rates of conduct, attention deficit-hyperactivity disorders and PTSD. These rates are higher than those reported internationally on children in non-conflict areas. A significant correlation was found between higher rates of lifetime trauma exposure, by frequency and type, and higher prevalence rates of mental health problems. The various state and non-governmental organizations involved in health care services are urged to use a community-based approach to alleviate the burden of suffering, including addressing issues of social justice for Palestinians.

Low-dose oral administration of interferon-alpha for the treatment of immune-mediated keratoconjunctivitis sicca in dogs

This preliminary study was designed to evaluate the effectiveness and dosage of oral use of interferon-alpha (IFN-alpha) in the treatment of naturally occurring, immune-mediated, canine keratoconjunctivitis sicca (KCS). Dogs with chronic immune-mediated KCS were selected from the two clinic populations. All medication, except topical artificial tears, was discontinued at least 2 weeks prior to beginning the clinical trial. IFN-alpha was administered orally once daily to the dogs by their owners as the sole therapy for the KCS. Examinations of the dogs were performed every 2 weeks for the duration of the trial (12 weeks). Each dog was given either two or three separate, escalating doses (20, 40, 80 IU of the IFN-alpha. A favorable response was observed in 55% (11/20) of all dogs treated. Clinical findings of those dogs that responded included increased wetting of the eyes, decreased mucus discharge, and fewer signs of discomfort. There was a nearly significant difference (p = 0.08) in pretreatment mean Schirmer's tear test (STT) between the dogs that responded (6.4 +/- SEM 0.62 mm/min) and those that did not respond (4.7 +/- SEM 0.69 mm/min) to the orally administered IFN-alpha. Seven of 11 dogs with favorable outcomes had an increased STT of at least 5 mm/min after treatment with oral IFN-alpha and the group had a post-treatment STT (10.5 +/- SEM 1.4 mm/min) significantly greater than baseline (p = 0.0004). The post-treatment STT of the dogs that did respond was significantly greater (p < 0.01) than the post-treatment mean STT of dogs that did not respond. All dogs that responded did so with the 20 or 40 IU dose of IFN-alpha. No side effects were noted and all dogs tolerated the treatment well.

Cloning and characterization of the EAP30 subunit of the ELL complex that confers derepression of transcription by RNA polymerase II

The product of the human oncogene ELL encodes an RNA polymerase II transcription factor that undergoes frequent translocation in acute myeloid leukemia (AML). In addition to its elongation activity, ELL contains a novel type of RNA polymerase II interaction domain that is capable of repressing polymerase activity in promoter-specific transcription. Remarkably, the ELL translocation that is found in patients with AML results in the deletion of exactly this functional domain. Here we report that the EAP30 subunit of the ELL complex has sequence homology to the Saccharomyces cerevisiae SNF8, whose genetic analysis suggests its involvement in the derepression of gene expression. Remarkably, EAP30 can interact with ELL and derepress ELL's inhibitory activity in vitro. This finding may reveal a key role for EAP30 in the pathogenesis of human leukemia.

Measuring the quality of diagnostic hypothesis sets for studies of decision support

Within medical informatics there is widespread interest in computer-based decision support and the evaluation of its impact. It is widely recognized that the measurement of dependent variables, or outcomes, represents the most challenging aspect of this work. This paper describes and reports the reliability and validity of an outcome metric for studies of diagnostic decision support. The results of this study will guide the analytic methods used in our ongoing multi-site study of the effects of decision support on diagnostic reasoning. Our measurement approach conceptualizes the quality of a diagnostic hypothesis set as having two components summed to generate a composite index: a Plausibility Component derived from ratings of each hypothesis in the set, whether correct or incorrect; and a Location Component derived from the location of the correct diagnosis if it appears in the set. The reliability of this metric is determined by the extent of interrater agreement on the plausibility of diagnostic hypotheses. Validity is determined by the extent to which the index generates scores that make sense on inspection (face validity), as well as the extent to which the component scores are non-redundant and discriminate the performance of novices and experts (construct validity). Using data from the pilot and main phases of our ongoing study (n = 124 subjects working 1116 cases), the reliability of our diagnostic quality metric was found to be 0.85-0.88. The metric was found to generate, on inspection, no clearly counterintuitive scores. Using data from the pilot phase of our study (n = 12 subjects working 108 cases), the component scores were moderately correlated (r = 0.68). The composite index, computed by equally weighting both components, was found to discriminate the hypotheses of medical students and attending physicians by 0.97 standard deviation units. Based on these findings, we have adopted this metric for use in our further research exploring the impact of decision support systems on diagnostic reasoning and will make it available to the informatics research community.

Homologous chromosome pairing in wheat

Bread wheat is a hexaploid (AABBDD, 2n=6x=42) containing three related ancestral genomes, each having 7 chromosomes, giving 42 chromosomes in diploid cells. During meiosis true homologues are correctly associated in wild-type wheat, but a degree of association of related chromosomes (homoeologues) occurs in a mutant (ph1b). We show that the centromeres are associated in non-homologous pairs in all floral tissues studied, both in wild-type wheat and the ph1b mutant. The non-homologous centromere associations then become homologous premeiotically in wild-type wheat in both meiocytes and the tapetal cells, but not in the mutant. In wild-type wheat, the homologues are colocalised along their length at this stage, but the telomeres remain distinct. A single telomere cluster (bouquet) is formed in the meiocytes only by the onset of leptotene. The sub-telomeric regions of the homologues associate as the telomere cluster forms. The homologous associations at the telomeres and centromeres are maintained through meiotic prophase, although, during leptotene, the two homologues and also the sister chromatids within each homologue are separate along the rest of their length. As meiosis progresses, first the sister chromatids and then the homologues associate intimately. In wild-type wheat, first the centromere grouping, then the bouquet disperse by the end of zygotene.

Characterisation of a mutant of barnacle troponin C lacking Ca2+-binding sites at positions II and IV

This study investigates a mutant barnacle troponin C (TnC) protein (BTnC2-4-) in which the Ca2+-binding sites (sites II and IV) have been rendered non-functional. Eliminating Ca2+ binding at both Ca2+-binding sites of barnacle TnC did not prevent the incorporation of BTnC2-4- into TnC-depleted myofibrillar bundles, although, as expected, the mutant was not able to effect muscle regulation. We conclude that the Mg2+ involved in stabilising the interaction between TnC and TnI in the barnacle must bind at a separate location to the Ca2+-binding sites. Competition experiments between BTnC2-4- and wild-type barnacle TnC (BTnCWT) or the native isoform BTnC2 indicate that BTnC2-4- has an approximately fourfold higher affinity for barnacle TnI than BTnCWT but a lower affinity for TnI compared to BTnC2. These results indicate that disabling sites II and IV changes the affinity of BTnC2-4- for TnC-denuded barnacle myofibrils, altering the stability of the bond formed between TnC and the thin filament.

Use of a custom retrograde intramedullary rod for the management of distal femoral nonunion: a report of two cases

Nonunion of the distal femur is a rare injury that is difficult to manage. A variety of surgical implants and techniques are available. We present an alternative mode of treatment for supracondylar femoral nonunion using a custom retrograde titanium femoral nail (Biomet; Warsaw, IN) to successfully achieve union in two cases. We believe the added length, custom modifications, and enhanced stability allowed better fixation in an osteopenic distal femur.

Influence of Inoculum Concentration on Production of Spermogonia and Aecia on Pine Seedlings Infected by Basidiospores of Cronartium quercuum f. sp. fusiforme

Seedlings of slash pine and loblolly pine inoculated with four concentrations of basidiospores of Cronartium quercuum f. sp. fusiforme and exhibiting large galls (≥25 mm long) were observed for spermogonial and aecial sporulation. Basidiospores from a genetically heterogeneous source at 50, 100, 1,000 and 5,000 spores/5-μl droplet were applied to the severed, succulent terminal of 6-week-old seedlings. Incidence of sporulation showing (i) spermatia (pycniospores) only, (ii) aeciospores only, (iii) spermatia and aeciospores, and (iv) absence of sporulation was recorded for 3 years. On slash pine, the percentage of seedlings showing only spermatia varied significantly and inversely with inoculum concentration. In contrast, the percentage of seedlings showing only aeciospores or aeciospores and spermatia varied directly with inoculum concentration. Results on loblolly pine were similar. It is suggested that, at low inoculum concentrations, hyphal anastomoses are limited by fewer haploid mycelia in infected tissues or fewer mating types resulting from incompatible host-parasite interactions.

Quantum-well states as fabry-Perot modes in a thin-film electron interferometer

Angle-resolved photoemission from atomically uniform silver films on iron (100) shows quantum-well states for absolutely determined film thicknesses ranging from 1 to approximately 100 monolayers. These states can be understood in terms of Fabry-Perot modes in an electron interferometer. A quantitative line shape analysis over the entire two orders of magnitude of thickness range yields an accurate measurement of the band structure, quasiparticle lifetime, electron reflectivity, and phase shift. Effects of confinement energy gap, reflection loss, and surface scattering caused by controlled roughness are demonstrated.

A diazo-2 study of relaxation mechanisms in frog and barnacle muscle fibres: effects of pH, MgADP, and inorganic phosphate

The aim of this study was to compare the effects of increased concentrations of MgADP, inorganic phosphate (Pi) and H+ ([MgADP], [Pi] and [H+], respectively) on the rate of relaxation in two different muscle types: skinned muscle fibres from the frog Rana temporaria and myofibrillar bundles from the giant Pacific acorn barnacle Balanus nubilus. Relaxation transients are produced by the photolysis of diazo-2 and are well fitted with a double exponential curve, giving two rate constants: k1 [5.6+/-0.1 s-1 for barnacle, n=30; 26.3+/-0.7 s-1 for frog, n=14 (mean+/-SEM)] and k2 [0.6+/-0.1 s-1 in barnacle, n=30; 10.4+/-1.0 s-1 in frog, n=14 (mean+/-SEM)], at 10 degrees C. Decreasing the pH by 0.5 pH units did not significantly affect k1 for barnacle relaxation [5.6+/-0.1 s-1 (mean+/-SEM), n=15] compared to the decrease in k1 of 40% seen in frog. Use of the Ca2+-sensitive fluorescent label acrylodan on barnacle wild-type troponin C demonstrated that decreasing the pH from 7.0 to 6.6 only alters the pCa50 value by 0.23 in the cuvette, while stopped-flow experiments with acrylodan revealed no significant change in koff from the labelled protein [322+/-32 s-1 at pH 7.0 and 381+/-24 s-1 (mean+/-SEM) at pH 6.6]. Increasing [MgADP] by 20 microM (50 microM added ADP) from control values of 50 microM in frog decreased k1 to 12.3+/-0.4 s-1 (mean+/-SEM, n=8), and at 400 microM MgADP, k1=9.6+/-0.1 s-1 (mean+/-SEM, n=12). In barnacle, 500 microM MgADP had a much smaller effect on k1 (4.0+/-0. 9 s-1, mean+/-SEM, n=8). Increasing the free [Pi] from the contaminant level of 0.36 mM to 1.9 mM slowed k1 by approximately 15% in barnacle [4.8+/-0.8 s-1, mean+/-SEM, n=7], compared to a approximately 30% reduction seen in frog. We conclude that the differences between barnacle and frog seen here are most probably due to different isomers of the contractile proteins, and that events underlying the crossbridge cycle are the same or similar. We interpret our results according to a model of crossbridge transitions during relaxation.

Intraepithelial and invasive squamous cell carcinoma of the conjunctiva: analysis of 60 cases

AIM

To evaluate the clinical features, treatment results, and recurrence rates in patients with either intraepithelial or invasive squamous cell carcinoma of the conjunctiva.

METHODS

Retrospective analysis of 60 cases (22 conjunctival intraepithelial and 38 invasive squamous cell carcinomas) to determine patterns of clinical presentation, aetiological factors, and treatment results. The mean patient age was 64 years old. 70% of the patients were male. Patients were treated with a variety of therapies, depending on the degree of tumour involvement; most cases were treated with frozen section controlled excision and adjunctive cryotherapy. Modified eye wall resection or enucleation was done for intraocular invasion and exenteration was done for orbital involvement.

RESULTS

Red eye (68%) and ocular irritation (57%) were the most common presenting symptoms. 44% of the patients had other eye findings consistent with extensive solar exposure. 20% of the patients had a history of malignant skin tumours. Visceral malignancies developed in 8%. Scleral involvement was present in 14 (37%), intraocular involvement in five (13%), and orbital invasion in four (11%) cases with invasive squamous cell carcinoma. After a mean follow up of 56 months (18-226 months) the rate of new or recurrent tumours was 4.5% for intraepithelial squamous carcinoma and 5.3% for invasive squamous cell carcinoma. No patient developed metastases or tumour related deaths.

CONCLUSION

Excision with intraoperative control of the surgical margins and adjunctive cryotherapy results in good tumour control rates.

An introductory hospice experience for third-year medical students

BACKGROUND

An organized and distinct curriculum in hospice and palliative care education is lacking in most United States medical school programs. Because of this knowledge deficit, physicians are often not able to meet the needs of their terminally ill patients and their families.

METHODS

A five-day combined didactic and clinical rotation in hospice and palliative care for third-year medical students was developed and is presented. The program is run through a home-based hospice in conjunction with the state's medical school.

RESULTS

The pilot program has been well accepted by the participating students as a valuable learning experience. Although brief, it has also been successful in changing some of their attitudes about death and the care of the dying.

CONCLUSIONS

This one-week program is an effective means to provide an intense course in hospice education. It should be easily transportable to other health care curricula.

A critical analysis of the pharmacology of AZT and its use in AIDS

The triphosphorylated form of the nucleoside analogue 3'-azido-3'-deoxythymidine (Zidovudine, AZT) is claimed to interrupt the HIV replication cycle by a selective inhibition of viral reverse transcriptase, thereby preventing the formation of new proviral DNA in permissive, uninfected cells. Given that initial HIV infection of an individual instigates abundant HIV replication from inception until death, and that the life of infected T-cells is only several days, the administration of AZT should lead both in vitro and in vivo (i) to decreased formation of proviral DNA; and thus (ii) to decreased frequencies of 'HIV isolation' (detection of p24 or reverse transcription or both) in stimulated cultures/cocultures of T-cells from seropositive individuals; (iii) to decreased synthesis of HIV p24 and RNA ('antigenaemia', 'plasma viraemia', 'viral load') ultimately resulting in low or absent levels of all three parameters; and (iv) to a perfect and direct correlation between all these parameters. A critical analysis of the presently available data shows that no such evidence exists, an outcome not unexpected given the pharmacological data on AZT. HIV experts all agree that only the triphosphorylated form of AZT (AZTTP) and not the unphosphorylated form administered to patients, nor its mono- or diphosphate, is the active agent. Furthermore, the mechanism of action is the ability of AZTTP to halt the formation of HIV-DNA (chain termination). However, although this claim was posited from the outset, AZT underwent clinical trials and was introduced as a specific anti-HIV drug many years before there were any data proving that the cells of patients are able to triphosphorylate the parent compound to a level considered sufficient for its putative pharmacological action. Notwithstanding, from the evidence published since 1991 it has become apparent that no such phosphorylation takes place and thus AZT cannot possess an anti-HIV effect. However, the scientific literature does elucidate: (i) a number of biochemical mechanisms which predicate the likelihood of widespread, serious toxicity from use of this drug; (ii) in vitro data proving that AZT has significant antibacterial and antiviral properties which confound interpretation of its effects when administered to patients. Based on all these data it is difficult if not impossible to explain why AZT was introduced and still remains the most widely recommended and used anti-HIV drug.

Catheter complications in AIDS patients treated for cytomegalovirus retinitis

PURPOSE

To describe the complications of central venous catheter use for intravenous therapy of cytomegalovirus (CMV) retinitis in patients with AIDS.

METHODS

Retrospective review of 388 patients with AIDS and CMV retinitis treated with intravenous medications through an indwelling catheter.

RESULTS

The catheter complication rate was 1.2 complications per person-year (0.33 complications per 100 catheter-days). Current injecting drug use increased the risk of infectious complications [hazard ratio (HR), 1.73; P=0.04] whereas former use did not (HR, 0.96; P=0.88). Subdermal port catheters increased the risk of bacteremia (HR, 1.78; P=0.05). Mortality for the first complication was 5.8%. Forty percent of patients required catheter removal, and 86.8% of these patients required reinsertion of another catheter.

CONCLUSIONS

Catheter complications are a substantial problem in patients with CMV retinitis treated with daily intravenous therapy.

Cervical epidural steroid injection with intrinsic spinal cord damage. Two case reports

STUDY DESIGN

Intrinsic cervical spinal cord damage represents the serious and permanent complications that can occur if cervical epidural steroid injections are administered while the patient is sedated. Two case reports are presented.

OBJECTIVES

To draw attention to the dangerous consequences that can arise from sedating a patient before administering a cervical epidural steroid injection.

SUMMARY OF BACKGROUND DATA

Reported complications of cervical epidural steroid injections have been minor and infrequent. No reports of intrinsic cervical cord damage could be found in a comprehensive English language literature search.

METHODS

Two case reports of permanent intrinsic cervical cord damage in patients who had been administered cervical epidural steroid injections while under intravenous sedation are presented. Magnetic resonance imaging was performed before and after the administration of cervical epidural steroid injections. Each patient had herniated nucleus pulposus before they received cervical epidural steroid injections and intrinsic cord damage on postinjection magnetic resonance images.

RESULTS

Both patients developed increased pain and neurologic symptoms within 24 hours of injection. To date, these symptoms appear to be permanent. However, Patient 1 had pain relief in her right arm and shoulder after undergoing a microdiscectomy, but pain was still persistent in her left leg, and she has developed a positive Lhermitte's sign.

CONCLUSION

These case reports indicate fluoroscopic guidance will not insure or prevent intrathecal perforation or spinal cord penetration during the administration of cervical epidural steroid injections. In addition, although intravenous sedations during cervical epidural steroid injections have been used numerous times without reported complications, it appears intravenous sedation in these two cases resulted in the inability of the patient to experience the expected pain and paresthesias at the time of spinal cord irritation. Therefore, the authors conclude that the patient should be fully awake during the administration of cervical epidural steroid injections, with only local anesthetic in the skin used for analgesia.

The value of imagery in perioperative nursing

Body/mind medicine is rapidly becoming one of the catalysts that will integrate conventional and complementary health care. Interactive Imagery, in particular, offers many potent healing opportunities for nurses and patients in the perioperative continuum. Within this holistic approach, nurses play a pivotal part in providing to patients self-care tools that can be applied in and out of the hospital. Imagery adds value to the health care system by offering nurses and other health care practitioners a way to empower themselves and their patients. It is harmless, time and cost-effective, and often fun, and it focuses on patient satisfaction.

Inhibition of human cytomegalovirus DNA maturation by a benzimidazole ribonucleoside is mediated through the UL89 gene product

2-Bromo-5,6-dichloro-1-beta-D-ribofuranosyl benzimidazole (BDCRB) is a member of a new class of benzimidazole ribonucleosides which inhibit human cytomegalovirus (HCMV) late in the replication cycle without inhibiting viral DNA synthesis. We show here that polygenomic concatemeric HCMV DNA does not mature to unit genome length in the presence of BDCRB. To discover the locus of action, virus resistant to BDCRB was selected by serial passage in the presence of the compound. Genetic mapping experiments with BDCRB-resistant virus demonstrated that the resistance phenotype mapped to one amino acid (Asp344Glu; low resistance) or two amino acids (Asp344Glu and Ala355Thr; high resistance) within the product of exon 2 of the HCMV U(L)89 open reading frame. The HCMV U(L)89 open reading frame and its homologs are among the most conserved open reading frames in the herpesviruses, and their products have sequence similarities to a known ATP-dependent endonuclease from the double-stranded DNA bacteriophage T4. These findings strongly suggest that BDCRB prevents viral DNA maturation by interacting with a U(L)89 gene product and that the U(L)89 open reading frame may encode an endonucleolytic subunit of the putative HCMV terminase. Further, since mammalian cell DNA replication does not involve a DNA maturation step, compounds which inhibit viral DNA maturation should be selective and safe.

Irrigation in facial and scalp lacerations: does it alter outcome?

STUDY OBJECTIVE

Animal and human studies suggest that irrigation lowers the infection rate in contaminated wounds, but there is no evidence that this common practice is beneficial for "clean" lacerations. We tested the null hypothesis that there is no difference in the infection rate for noncontaminated lacerations to the face and scalp that are irrigated before primary closure compared with similar wounds that are closed primarily without irrigation.

METHODS

We performed a cross-sectional study of consecutive patients presenting to a suburban, academic emergency department between October 1992 and August 1996. Patients with nonbite, noncontaminated facial skin or scalp lacerations who presented less than 6 hours after injury were included. Structured, closed-question data collection instruments were completed at the time of laceration repair and at suture removal. The primary outcome parameters were the incidence of wound infection and the short-term cosmetic appearance of lacerations in patients who did or did not receive irrigation.

RESULTS

A total of 1,923 patients were included in the study group; 1,090 patients received saline irrigation, and 833 patients did not. The irrigation and nonirrigation groups were similar with regard to time from injury to presentation (1.56 versus 1.42 hours, respectively), frequency of linear wound morphology (82% versus 88%), frequency of smooth wound margins (72% versus 82%), number of layers of closure (1.14 versus 1.26), number of skin sutures applied (4.98 versus 4.65), number of deep sutures applied (.70 versus 1.05), and use of oral antibiotic prophylaxis (2.8% versus 4.0%). With respect to outcomes, the incidence of wound infection was not significantly different between the two treatment groups (.9% versus 1.4%, respectively; P = .28). Likewise, the percentage of patients who had an "optimal" cosmetic appearance was similar in the two groups (75.9% versus 81.7%, respectively; P = .07).

CONCLUSION

Irrigation before primary closure did not significantly alter the rate of infection or the cosmetic appearance in our study population with clean, noncontaminated facial and scalp lacerations.

Association of homologous chromosomes during floral development

Reduction in chromosome number and genetic recombination during meiosis require the prior association of homologous chromosomes, and this has been assumed to be a central event in meiosis. Various studies have suggested, however, that while the reduction division of meiosis is a universally conserved process, the pre-meiotic association of homologues differs among organisms. In the fruit fly Drosophila melanogaster, some somatic tissues also show association of homologues [1,2]. In the budding yeast Saccharomyces cerevisiae, there is some evidence for homologue association during the interphase before meiotic division [3,4], and it has been argued that such associations lead directly to meiotic homologue pairing during prophase I [5]. The available evidence for mammals suggests that homologous chromosomes do not associate in germ cells prior to meiotic prophase [6]. To study the occurrence of homologue pairing in wheat, we have used vibratome tissue sections of wheat florets to determine the location of homologous chromosomes, centromeres and telomeres in different cell types of developing anthers. Fluorescence in situ hybridization followed by confocal microscopy demonstrated that homologous chromosomes associate pre-meiotically in meiocytes (germ-line cells). Surprisingly, association of homologues was observed simultaneously in all the surrounding somatic tapetum cells. Homologues failed to associate at equivalent stages in a homologue recognition mutant. These results demonstrate that the factors responsible for the recognition and association of homologues in wheat act before the onset of meiotic prophase. The observation of homologue association in somatic tapetum cells demonstrates that this process and meiotic division are separable.

Centromeric behaviour in wheat with high and low homoeologous chromosomal pairing

Control of homoeologous chromosomal pairing in hexaploid wheat stems from a balance between a number of suppressor and promoter genes. This study used centromeric behaviour as a tool to investigate the mechanism. Fluorescent in situ hybridization employing centromeric and telomeric sequences as probes was applied to pollen mother cells of wheat and wheat/alien hybrids having different pairing gene combinations. It showed: association of centromeres during pre-meiotic interphase; decondensation of centromeric structure; sister chromatid disjunction of univalent chromosomes in homoeologous pairing situations at anaphase I; and centromeric stretching between univalent sister chromatids in wheat/rye hybrids deficient for pairing genes. The implications of these results are discussed.

Ear dominance and telephone sales

In a field study, three equally sized sales teams used on of three head-sets--left, right, both ears--for a day's selling of insurance by telephone. This had no effect on sales. In a retrospective study of records, daily sales performance including the percentage conversion rate for sales divided by the number of calls and the number and duration of calls was related to preference for type of head-set. Sales were markedly influenced by the choice of head-set. People who chose to wear the left earpiece significantly out sold the others wearing right and stereohead-sets. Neither the number of incoming calls nor the time spent on the telephone were influenced by the choice of head-set. When sales are analysed in terms of individual differences in personal preference for type of head-set, those who chose the left ear had an advantage. Forced use of the left, versus right ear or both ears for one day had no effect.

Transplantation of autologous peripheral blood progenitor cells procured after high-dose cytarabine-based consolidation chemotherapy for adults with acute myelogenous leukemia in first remission

The purpose of the study was to evaluate the feasibility and efficacy of high-dose cytarabine-anthracycline consolidation chemotherapy followed by autologous transplantation of chemotherapy/rHuG-CSF-mobilized peripheral blood progenitor cells for adult patients with acute myelogenous leukemia in first remission. Fifty-nine consecutive patients (median age 45, range 18-69) with acute myelogenous leukemia in first remission were enrolled on a study of high-dose cytarabine-mitoxantrone consolidation chemotherapy used as a method of in vivo purging for the purpose of autologous peripheral blood progenitor cell transplantation. A median of 7 x 10(8) peripheral blood mononuclear cells/kg were infused 1 day after preparative conditioning with 11.25 Gy total body irradiation and cyclophosphamide (120 mg/kg). Forty-six patients received myeloablative chemo-radiotherapy followed by the infusion of chemotherapy/rHu-G-CSF-mobilized autologous peripheral blood progenitor cells. The median time to both neutrophil and platelet recovery from transplant was 15 days (range, 11-36 and 5-253+ days, respectively). After a median follow-up of 27 months, 31 patients remain alive with 27 in complete remission. Median remission duration for all eligible patients is 12 months, and actuarial leukemia-free survival at 3 years is 42 +/- 14%. The actuarial risk of relapse is 54 +/- 15%. Toxicity of autologous peripheral blood progenitor cell transplant included treatment-related death in two patients and grade III/IV organ toxicity in six. Advanced age was a negative prognostic factor for leukemia-free survival. Our results demonstrate that autologous transplantation of chemotherapy-mobilized peripheral blood progenitor cells is feasible in an unselected population of adult patients with acute myelogenous leukemia in first remission producing improved leukemia-free survival with minimal toxicity.

Role of endothelin in mediating the attenuated renal hemodynamics in Dahl salt-sensitive hypertension

The aim of this study was to evaluate the role of endothelin (ET) in the hypertension associated with giving a high sodium diet in Dahl salt-sensitive (DS) rats. To achieve this goal, we examined the effects of intravenous infusion of the nonspecific ET(A)-ET(B) antagonist on arterial pressure and renal function in conscious, chronically instrumented DS and Dahl salt-resistant (DR) rats. After 3 weeks on a high sodium (8%) diet, mean arterial pressure (MAP) in DS rats (166+/-3 mm Hg) was significantly higher than in DR rats (124+/-3 mm Hg). Baseline glomerular filtration rate (GFR) and renal plasma flow (RPF) in DS rats (1.92+/-0.25 mL/min and 7.07+/-0.80 mL/min) were lower than in DR rats (2.52+/-0.21 mL/min and 7.98+/-0.85 mL/min), respectively. Renal vascular resistance was significantly higher in DS rats (32.78+/-5.88 mm Hg x mL(-1) x min(-1)) than in DR rats (24.60+/-5.04 mm Hg x mL(-1) x min(-1)). Intravenous infusion of the ET antagonist SB 209670 at a dose of 30 microg x kg(-1) x min(-1) for 75 minutes caused a significant decrease in MAP in DS rats (from 166+/-3 to 144+/-4 mm Hg). In contrast, the effect of the ET antagonism on MAP in DR rats was not significant. ET-antagonist infusion tended to improve GFR and RPF in DS but not in DR rats. To determine the renal effects of ET antagonism independent of the systemic hemodynamic responses, we examined the effects of the same ET antagonist in rats chronically implanted with a renal interstitial catheter. Arterial pressure in DS rats (181+/-5 mm Hg) was significantly higher than in DR rats (135+/-3 mm Hg). Renal interstitial infusion of SB 209670 at a dose of 200 ng x kg(-1) x min(-1) for 60 minutes caused no change in MAP in DS or DR rats. Intrarenal ET antagonism significantly increased GFR (25%), RPF (30%), urine flow (32%), and urinary sodium excretion (25%) in DS rats, while it had no significant effect in DR rats. Fractional excretion of sodium was not significantly changed by renal interstitial infusion of the ET antagonist in DS rats, indicating that improved renal excretory function in DS rats is most likely due to the associated improvement in renal hemodynamics. We conclude that ET may play a role in the attenuated renal hemodynamics and possibly the development of Dahl salt-sensitive hypertension.

Are rice chromosomes components of a holocentric chromosome ancestor?

Comparative genomics reveals that cereal genomes are composed of similar genomic building blocks (linkage blocks). By stacking these blocks in a unique order, it is possible to construct a single ancestral 'chromosome' which can be cleaved to give the basic structure of the 56 different chromosomes found in wheat, rice, maize, sorghum, millet and sugarcane. The borders of linkage blocks are defined by cereal centromeric and telomeric sites. However, a number of studies have shown that telomeric heterochromatin has neocentromeric activity, implying that linkage blocks are in fact defined by centromeric-like sites with conserved sequences. The structure of the ancestral cereal genome thus resembles a holocentric chromosome, which is the chromosome structure shared by the closest relatives of the Gramineae, the Cypericeae and Juncaceae.

Picture archiving and communication system implementation: the practical considerations of adapting the technology to the real world of health care operations

The issues discussed in this article are just some of the real-life considerations a facility's management team should address during the planning process as they make decisions about PACS implementation. We currently are working with the management teams of many facilities on PACS implementation projects that have yet to be completed. In the future, we hope to report on our experiences, including both successes and failures, as construction is completed and the systems actually are implemented.

Virtual bronchoscopy with perfluoronated hydrocarbon enhancement

RATIONALE AND OBJECTIVES

Bronchoscopic computed tomography (CT) is limited by machine resolution and air-soft-tissue contrast. The objective of this study was to determine whether improving the contrast by using the contrast agent perflubron (PFOB) in the lung would improve the bronchoscopic CT technique and permit visualization of small airways.

MATERIALS AND METHODS

Bronchoscopic CT was performed in an anesthetized 8-week-old New Zealand white rabbit before and after the endotracheal administration of PFOB.

RESULTS

Bronchoscopic CT performed with PFOB permitted navigation of bronchi as small as 0.8 mm in diameter, which are much smaller than those that can be navigated without PFOB.

CONCLUSION

In this example, the use of perfluorochemicals with bronchoscopic CT enhanced the capabilities of virtual bronchoscopy.

Immunogenic characterization of a tissue culture-derived vaccine that affords partial protection against avian coccidiosis

The immunogenicity of a tissue culture-derived vaccine generated from an Eimeria tenella-infected cell line in a serologically defined bird line, and the ability to confer protection against homologous challenge in young chicks was examined. The cell line, SB-CEV-1/F7, was infected with E. tenella sporozoites and the resulting 72-h postinfection cell-free supernatants were adjuvanted and used to immunize Leghorn chicks homozygous for the B19 haplotype. Peripheral blood and splenic lymphocytes from these immunized birds proliferated in vitro in response to both sporozoite and SB-CEV-1/F7 tissue culture-derived parasite antigens. In addition, splenic immune lymphocytes obtained from birds previously exposed to E. tenella in vivo responded to these tissue culture-derived parasite antigens in vitro. To evaluate the efficacy of the vaccine, B19B19 chicks were vaccinated s.c. with adjuvanted 72-h postinfection cell-free supernatants or an ammonium sulfate precipitate derivative thereof, orally boosted, and then subjected to homologous parasite challenge at 10 d of age. The level of protection (body weight gain, cecal lesions) was assessed 6 d after challenge. Performance results from four battery trials demonstrated that vaccinated birds were significantly protected against weight loss compared to unimmunized, challenged controls. In addition, in two of the four trials, vaccinated birds were significantly protected against lesions. These results provide strong evidence that tissue culture-derived parasite antigens obtained from the E. tenella-infected SB-CEV-1/F7 cell line are immunogenic in birds and can provide partial protection against E. tenella clinical coccidiosis.

Optical properties of deep ice at the South Pole: absorption

We discuss recent measurements of the wavelength-dependent absorption coefficients in deep South Pole ice. The method uses transit-time distributions of pulses from a variable-frequency laser sent between emitters and receivers embedded in the ice. At depths of 800-1000 m scattering is dominated by residual air bubbles, whereas absorption occurs both in ice itself and in insoluble impurities. The absorption coefficient increases approximately exponentially with wavelength in the measured interval 410-610 nm. At the shortest wavelength our value is approximately a factor 20 below previous values obtained for laboratory ice and lake ice; with increasing wavelength the discrepancy with previous measurements decreases. At ~415 to ~500 nm the experimental uncertainties are small enough for us to resolve an extrinsic contribution to absorption in ice: submicrometer dust particles contribute by an amount that increases with depth and corresponds well with the expected increase seen near the Last Glacial Maximum in Vostok and Dome C ice cores. The laser pulse method allows remote mapping of gross structure in dust concentration as a function of depth in glacial ice.

Frequent loss of heterozygosity on chromosome arm 18q in squamous cell carcinomas. Identification of 2 regions of loss--18q11.1-q12.3 and 18q21.1-q23

OBJECTIVES

To determine the frequency and regions of loss on chromosome arm 18q in uncultured head and neck squamous cell carcinomas.

DESIGN

Polymerase chain reaction amplification of DNA extracted from 18 tumor specimens (1 patient had 2 tumors) and blood samples from 17 patients with head and neck squamous cell carcinoma was performed using primers flanking 16 microsatellite repeat polymorphisms spanning most of chromosome 18q. DNA was extracted only from specimens with greater than 70% tumor nuclei.

SETTING

Research university.

PATIENTS

Seventeen individuals with newly diagnosed head and neck cancer.

MAIN OUTCOME MEASURE

Loss of heterozygosity (LOH).

RESULTS

There was LOH at more than 1 locus in 52% (9/ 17) of the tumors; 3 tumors had LOH at all informative markers. Four had loss at only 1 locus, raising the total with loss to 12 (75%) of 16. Loss of 18q11.1-q12.3 in 4 tumors without distal loss defines a proximal region of loss. Loss of heterozygosity affecting 18q21.1 in 1 tumor, without proximal loss and LOH for 18q21.1, 18q22, or 18q23 in 9 (52%) of 17 tumors defines a distal region of loss.

CONCLUSIONS

Loss of heterozygosity on chromosome arm 18q is not an artifact of in vitro culture. The finding of 18q LOH in 50% to 70% tumors makes 18q an important region for study. Regions 18q11.1-q12.3 and 18q21.1-q23 are common regions of loss, indicating that there may be more than one 18q tumor suppressor gene involved in the genesis and progression of head and neck squamous cell carcinomas.

United States passenger-vehicle crashes by crash geometry: direct costs and other losses

The personal and societal losses caused by motor-vehicle crashes are significant. This paper provides tools that describe these losses for 30 different crash geometries. Persons involved with the development and implementation of crash countermeasures can use these tools to prioritize their countermeasure approach. Multiple vehicle crashes currently account for much larger direct costs but only slightly more years lost than single vehicle crashes. Direct expenditures on multiple vehicle crashes exceed $41 billion per year; they claim 974,000 years of life and functioning. Direct expenditures on single vehicle crashes exceed $18 billion per year; they claim 937,000 years of life and functioning.

Orbital metastases: diagnosis and course

AIMS

Three issues were investigated in adult outpatients with orbital metastases. One, how accurate are current diagnostic methods? Two, what is the survival associated with orbital metastases? Three, did any clinical factors correlate with prognosis in this patient cohort?

METHODS

Retrospective analysis of patients with orbital metastases managed in an ocular oncology unit.

RESULTS

11 of 31 (35%) patients had no known primary malignancy at the time of orbital diagnosis. In eight of 31 (26%) computed tomography and/or magnetic resonance imaging data did not yield the diagnosis of metastases. In 15 of 17 (88%) cases a fine needle aspiration biopsy was diagnostic. Several types of therapy were used. The median survival was 1.3 years.

CONCLUSION

Orbital metastases, even with newer diagnostic techniques can be difficult to diagnose. Management was based on location and extent of both orbital and systemic disease as well as vision. In most cases, orbital symptoms were palliated; however, survival was dismal. No clinical factor correlated with prognosis.