Isolation and functional analysis of neutrophils

This unit describes the isolation of high-purity neutrophils (or polymorphonuclear leukocytes; PMN) and the assays that can be performed to assess their function. An assay for the in vitro study of phagocytic capacity is presented, and microbicidal assays using lysostaphin and differential centrifugation are also described. During phagocytosis or on exposure to soluble agonists, neutrophils exhibit a marked increase in oxidative metabolism which is mediated by activation of NADPH oxidase and results in the formation of superoxide anion as well as hydrogen peroxide and other reactive species. The nitroblue tetrazolium reduction slide test is presented, and is a nonquantitative screening test for the presence of reactive oxygen products. The quantitation of superoxide by the kinetic and static assays are detailed, and a "broken cell" assay is also outlined.Finally, measurement of hydrogen peroxide formation is described.

Alcohol consumption, ART usage and high-risk sex among women infected with HIV

We examine the role of alcohol consumption on sexual risk behavior among a cohort of 187 sexually active HIV-infected women (aged 18-61) in care at an urban ambulatory clinic in New Orleans, Louisiana, U.S. Sexual risk behavior among women on and off antiretroviral therapy (ART) and the relationship between alcohol use, ART, and behavior was also explored. One-fourth of respondents were classified as binge drinkers and the average number of drinking occasions per week ranged from none to 10-12. Approximately 60% were prescribed ART and self-reported adherence was 90%. One-third of the women reported no condom use at last vaginal sex, 62% reported inconsistent condom use for vaginal sex, and 7% had multiple male sex partners in the last month. Binge alcohol users and women on ART were significantly more likely to participate in each sexual risk outcome examined. Partner refusal of condom use was also significantly associated with binge drinking patterns. Results lend strength to the equivocal literature on the relationship between both alcohol and prescription of ART and sexual behavior. Enhanced detection of alcohol abuse, coupled with risk reduction counseling especially among women prescribed ART are important clinical practices in treating women with HIV.

An Investigation into the Dynamic Effects on the Track of Wheelflats on Railway Vehicles

Wheelflats on railway vehicles are created by wheelslide in braking: the resulting imperfection in the running line generates dynamic forces and stresses at each subsequent revolution. The authors describe this problem and refer to earlier work on this topic. A field experiment is described, in which an irregularity in the railhead was used to simulate a wheelflat for a range of vehicles, and loads and rail stresses were monitored. The structure and solution procedures of three theoretical models of the vehicle/track system are outlined and typical results are compared with the experimental data to establish the adequacy and limitations of each of the models.

Although this paper is primarily concerned with railway track dynamics, the mathematical techniques described could be applied to any problem involving the impact loading of beams.

Reliability and validity of the SF-36 in HIV-infected homeless and marginally housed individuals

OBJECTIVE

To assess the reliability and validity of the Short-Form 36 (SF-36) health survey as a health status indicator among HIV-infected homeless and marginally housed (HMH) individuals.

METHODS

Between July 1996 and May 2000, a sample of HMH individuals completed interviews that included the SF-36. Responses to the SF-36 were analyzed for missing data, range, internal consistency, and construct validity.

RESULTS

Among 330 individuals interviewed, 83% were male, 43% were African-American, and the median age was 39 years. All internal consistency reliability coefficients exceeded 0.70, all item-scale correlations exceeded 0.40, all items were more strongly correlated with their hypothesized scale than any other scale, and all reliability coefficients exceeded inter-scale correlations for the same scale. Three of four physical health scales were significantly associated with CD4 cell count and HIV viral load. All scales were significantly associated with depression.

DISCUSSION

We found that scales were internally consistent, items correlated to an acceptable degree with their hypothesized scales, items were distinct from other scales, physical scales were associated with CD4 cell count and viral load, and all scales were associated with depression. These analyses provide evidence for the reliability and validity of the SF-36 as a measure of health status in HIV-positive HMH individuals.

What predicts poor collection of medication among children with asthma? A case-control study

Compliance with asthma medication is recognised to be a problem. Acquisition of medication is the first step towards compliance. Factors predicting poor collection of prophylactic medication were investigated. A case/control study was conducted. Cases were children who had had at least two consultations for poorly controlled asthma in 1 yr and collected prescriptions of prophylactic medication irregularly. Controls were children whose prescriptions were collected as instructed. Levels of knowledge about asthma and asthma medication were high in both groups. Parents of cases were more likely to perceive their child's asthma to be moderate or severe and more likely to report that their child's asthma was not well controlled. They reported more night-time symptoms, exercise symptoms and school absence. Parents of cases were less likely to report that administering inhalers was part of the evening routine. They were less likely to perceive their child's prophylactic medication to be very effective and more reluctant to administer prophylactic medication. Some parents may decide to undertreat their children, although lack of organised routine may contribute to poor compliance. Parents need guidance on interpreting symptoms and support in establishing routines for the administration of medication.

Cost consequences of sentinel lymph node biopsy in the treatment of breast cancer. A preliminary analysis

OBJECTIVES

To assess whether sentinel lymph node biopsy (SLNB), an alternative to axillary lymph node dissection in treating female breast cancer, affords any cost savings.

METHODS

We profile cumulative treatment costs of 811 breast cancer patients, 555 of whom received SLNB. Univariate and multivariate statistical tests are used to appraise whether these cost profiles differ between SLNB and other patients.

RESULTS

The statistical results are mixed. However, none supports the conjecture that SLNB necessarily lowers the cost of treating the average breast patient.

CONCLUSIONS

SLNB may be cost-effective, but longer term costs and outcomes must be estimated before firm conclusions can be reached.

Fibrinogen and fibrin are anti-adhesive for keratinocytes: a mechanism for fibrin eschar slough during wound repair

During cutaneous wound repair the epidermis avoids the fibrin-rich clot; rather it migrates down the collagen-rich dermal wound margin and over fibronectin-rich granulation tissue. The mechanism(s) underlying keratinocyte movement in this precise pathway has not been previously addressed. Here we demonstrate that cultured human keratinocytes do not express functional fibrinogen/fibrin receptors, specifically alpha v beta 3. Biologic modifiers known to induce integrin expression or activation did not induce adhesion to fibrin, fibrinogen, or its fragments. Epidermal explant outgrowth and single epidermal cell migration failed to occur on either fibrin or fibrinogen. Surprisingly, fibrin and fibrinogen mixed at physiologic molar ratios with fibronectin abrogated keratinocyte attachment to fibronectin. Keratinocytes transduced with the beta 3 integrin subunit cDNA, expressed alpha v beta 3 on their surface and attached to and spread on fibrinogen and fibrin. beta-gal cDNA-transduced keratinocytes did not demonstrate this activity. Furthermore, beta 3 cDNA-transduced keratinocyte adhesion to fibrin was inhibited by LM609 monoclonal antibody to alpha v beta 3 in a concentration-dependent fashion. From these data, we conclude that normal human keratinocytes cannot interact with fibrinogen and its derivatives due to the lack of alpha v beta 3. Thus, fibrinogen and fibrin are authentic anti-adhesive for keratinocytes. This may be a fundamental reason why the migrating epidermis dissects the fibrin eschar from wounds.

Transient eruptive seborrheic keratoses associated with erythrodermic psoriasis and erythrodermic drug eruption: report of two cases

The appearance of multiple seborrheic keratoses in association with underlying internal malignancy (known as the sign of Leser-Trelat) has generated much discussion and debate in the literature. However, comparatively few case reports exist that examine the appearance of multiple seborrheic keratoses associated with exfoliative erythroderma without underlying malignancy. We report 2 cases in which multiple, biopsy-proven seborrheic keratoses appeared in conjunction with erythrodermic skin eruptions. The underlying diseases in these 2 patients included psoriasis and an eczematous drug eruption; in both cases the erythroderma resolved with appropriate treatment. After resolution of the erythroderma, the newly developed seborrheic keratoses proceeded to involute and gradually fall off. Neither of the patients exhibited any evidence of internal malignancy. These cases represent the first reports of psoriasis and drug eruption as causes of erythroderma-induced transient eruptive seborrheic keratoses. Clinical and pathologic findings are consistent with previous descriptions of this entity.

Frequency of anovulation and early menopause among women enrolled in selected adult AIDS clinical trials group studies

To obtain information on the prevalence of anovulation and early menopause and on pituitary-gonadal function among human immunodeficiency virus type 1-infected women, a study was undertaken that used stored serum samples from women aged 20-42 years who participated in selected Adult AIDS Clinical Trials Group protocols. Defined progesterone and follicle-stimulating hormone (FSH) levels were considered presumptive evidence of ovulation and of menopause, respectively. Anovulation occurred in 16 (48%) of 33 women for whom progesterone levels were tested; early menopause occurred in 2 (8%) of 24 women for whom FSH levels were tested. No statistically significant differences were seen in the demographic and clinical characteristics of anovulatory and ovulatory women, although women who ovulated had higher CD4 T cell counts and were less likely to have reported a recent change in menstrual periods. These data support the findings of prior studies of increased frequency of amenorrhea and/or irregular menstrual cycles, particularly among women with lower CD4 T cell counts.

Digital mammography: wavelet transform and Kalman-filtering neural network in mass segmentation and detection

RATIONALE AND OBJECTIVES

The authors developed a new adaptive module to improve their computer-assisted diagnostic (CAD) method for mass segmentation and classification. The goal was an adaptive module that used a novel four-channel wavelet transform with neural network rather than a two-channel wavelet transform with manual subimage selection. The four-channel wavelet transform is used for image decomposition and reconstruction, and a novel Kalman-filtering neural network is used for adaptive subimage selection.

MATERIALS AND METHODS

The adaptive CAD module was compared with the nonadaptive module by comparing receiver operating characteristic curves for the whole CAD system. An image database containing 800 regions of interest enclosing all mass types and normal tissues was used for the relative comparison of system performance, with electronic ground truth established in advance.

RESULTS

The receiver operating characteristic curves yield Az values of 0.93 and 0.86 with and without the adaptive module respectively, suggesting that overall CAD performance is improved with the adaptive module.

CONCLUSION

The results of this study confirm the importance of using a new class of adaptive CAD methods that allow a more generalized application for larger image databases or images generated from different sensors or by means of direct x-ray detection, as required for clinical trials.

Transcriptional regulation of the p67phox gene: role of AP-1 in concert with myeloid-specific transcription factors

We have investigated the myeloid-specific transcriptional regulation of p67(phox), an essential component of phagocyte respiratory burst NADPH oxidase. Analysis was carried out on the p67(phox) 5'-flanking region from -3669 to -4 (relative to ATG), including the first exon and intron and part of the second exon. The construct extending from -985 to -4 produced the highest luciferase activity in myeloid HL-60 cells but was not active in HeLa or Jurkat cells, indicating myeloid-specific expression. Four active elements were identified: Sp1/Sp3 at -694, PU.1 at -289, AP-1 at -210, and PU.1/HAF1 at -182, the latter three being in the first intron. These cis elements bound their cognate transacting factors both in vitro and in vivo. Mutation of the Sp1, PU.1, or PU.1/HAF1 site each decreased promoter activity by 35-50%. Mutations in all three sites reduced promoter activity by 90%. However, mutation of the AP-1 site alone nearly abolished promoter activity. The AP-1 site bound Jun and Fos proteins from HL-60 cell nuclear extract. Co-expression with Jun B in AP-1-deficient cells increased promoter activity by 3-fold. These data show that full p67(phox) promoter activity requires cooperation between myeloid-specific and nonmyeloid transcription factors, with AP-1 being the most critical for function.

Magnetic resonance imaging of the breast

BACKGROUND

Magnetic resonance imaging (MRI) has the potential to become a useful adjunct in breast imaging. Contrast-enhanced breast MRI has demonstrated a high sensitivity in the detection of invasive breast cancer. In clinical studies, breast MRI has often altered the course of patient care. Although promising results have been generated, MRI of the breast is currently in a development stage.

METHODS

The authors reviewed the literature on the potential indications, sensitivity, specificity, and limitations of MRI of the breast.

RESULTS

Reported advantages of MRI of the breast over conventional imaging techniques include improved staging and treatment planning, enhanced evaluation of the augmented breast, better detection of recurrence, and improved screening of high-risk women. Contrast-enhanced breast MRI is a sensitive modality for detecting breast cancer, but its variable specificity is a major limitation.

CONCLUSIONS

MRI of the breast is emerging as a valuable adjunct to mammography and sonography for specific clinical indications. Additional clinical studies that define indications, interpretation criteria, imaging parameters, and cost effectiveness are needed. A multi-institutional study designed to address these issues is in progress.

Fibrin and wound healing

Although hemostasis is the major role of fibrin in wound repair, once the clot is present the wound cells must deal with it. The invasion and clearing of fibrin by these cells involves multiple complex processes that may go array XXX and delay wound repair. A good example, of the latter is leg ulcers. These chronic wounds contain a plethora of proteases that digest fibronectin and growth factors in the fibrin clot resulting in a corrupt provisional matrix that no longer supports reepithelialization or granulation tissue formation. Every good wound care provider knows that these wounds will not heal unless the corrupt matrix is removed by vigorous debridement that stimulates the accumulation of a competent provisional matrix.

Improved method for automatic identification of lung regions on chest radiographs

RATIONALE AND OBJECTIVES

The authors performed this study to evaluate an algorithm developed to help identify lungs on chest radiographs.

MATERIALS AND METHODS

Forty clinical posteroanterior chest radiographs obtained in adult patients were digitized to 12-bit gray-scale resolution. In the proposed algorithm, the authors simplified the current approach of edge detection with derivatives by using only the first derivative of the horizontal and/or vertical image profiles. In addition to the derivative method, pattern classification and image feature analysis were used to determine the region of interest and lung boundaries. Instead of using the traditional curve-fitting method to delineate the lung, the authors applied an iterative contour-smoothing algorithm to each of the four detected boundary segments (costal, mediastinal, lung apex, and hemidiaphragm edges) to form a smooth lung boundary.

RESULTS

The algorithm had an average accuracy of 96.0% for the right lung and 95.2% for the left lung and was especially useful in the delineation of hemidiaphragm edges. In addition, it took about 0.775 second per image to identify the lung boundaries, which is much faster than that of other algorithms noted in the literature.

CONCLUSION

The computer-generated segmentation results can be used directly in the detection and compensation of rib structures and in lung nodule detection.

Timing of postoperative adjustment in adjustable suture strabismus surgery

PURPOSE

The use of adjustable sutures in strabismus surgery has increased the rate of surgical success. Little data are available on the optimum timing for postoperative adjustment after strabismus surgery. We wanted to compare 2 common practices of adjustable suture technique after strabismus surgery.

METHODS

Two comparable groups of 40 patients each, who had strabismus surgery with adjustable suture technique, were prospectively studied. Group A had early adjustment the same day of the surgery about 6 hours after the operation, and group B had late adjustment the next day about 24 hours after the operation. Subjective scoring tables were used to evaluate the pain felt by the patient before, during, and after the adjustment and any difficulties of the adjustment process. Requirements of postoperative pain medications and final alignment 6 weeks after surgery were also compared.

RESULTS

Despite adequate statistical power, no significant differences were found between the groups regarding pain before, during, and after adjustment, difficulties performing the adjustment, and final alignment after 6 weeks (P > .05). Both adjustment schedules were equally associated with mild to moderate pain before, during, and after the adjustment. In the first 24 hours after surgery, no overall difference in the use of pain medications was found. Nausea and vomiting in the first 24 postoperative hours were more common in the early adjustment group (P = .02).

CONCLUSION

The surgeon can feel free to choose the timing for postoperative adjustment. However, when performing an early adjustment, the surgeon should be especially prepared to control nausea and vomiting.

Concordance between the CC chemokine receptor 5 genetic determinants that alter risks of transmission and disease progression in children exposed perinatally to human immunodeficiency virus

If CC chemokine receptor 5 (CCR5)-dependent mechanisms at the time of initial virus exposure are important determinants of virus entry and disease outcome, then the polymorphisms in CCR5 that influence risk of transmission and disease progression should be similar; this hypothesis was tested in a cohort of 649 Argentinean children exposed perinatally to human immunodeficiency virus type 1 (HIV-1). Two lines of evidence support this hypothesis. First, CCR5 haplotype pairs associated with enhanced risk of transmission were the chief predictors of a faster disease course. Second, some of the haplotype pairs associated with altered rates of transmission and disease progression in children were similar to those that we previously found influenced outcome in European American adults. This concordance suggests that CCR5 haplotypes may serve as genetic rheostats that influence events occurring shortly after initial virus exposure, dictating not only virus entry but, by extension, also the extent of early viral replication.

Cases from the Aerospace Medicine Residents' Teaching File: acute onset of dizziness in a USAF aviator

An Air Force F-15 pilot develops the sudden onset of incapacitating dizziness with nausea and vomiting not associated with flight. Presentation, diagnosis, treatment, and aeromedical issues surrounding the symptom complex of acute onset vertigo is discussed.

Global survey of genetic variation in CCR5, RANTES, and MIP-1alpha: impact on the epidemiology of the HIV-1 pandemic

Expression of CC chemokine receptor 5 (CCR5), the major coreceptor for HIV-1 cell entry, and its ligands (e.g., RANTES and MIP-1alpha) is widely regarded as central to the pathogenesis of HIV-1 infection. By surveying nearly 3,000 HIV+ and HIV- individuals from worldwide populations for polymorphisms in the genes encoding RANTES, MIP-1alpha, and CCR5, we show that the evolutionary histories of human populations have had a significant impact on the distribution of variation in these genes, and that this may be responsible, in part, for the heterogeneous nature of the epidemiology of the HIV-1 pandemic. The varied distribution of RANTES haplotypes (AC, GC, and AG) associated with population-specific HIV-1 transmission- and disease-modifying effects is a striking example. Homozygosity for the AC haplotype was associated with an increased risk of acquiring HIV-1 as well as accelerated disease progression in European Americans, but not in African Americans. Yet, the prevalence of the ancestral AC haplotype is high in individuals of African origin, but substantially lower in non-Africans. In a Japanese cohort, AG-containing RANTES haplotype pairs were associated with a delay in disease progression; however, we now show that their contribution to HIV-1 pathogenesis and epidemiology in other parts of the world is negligible because the AG haplotype is infrequent in non-Far East Asians. Thus, the varied distribution of RANTES, MIP-1alpha, and CCR5 haplotype pairs and their population-specific phenotypic effects on HIV-1 susceptibility and disease progression results in a complex pattern of biological determinants of HIV-1 epidemiology. These findings have important implications for the design, assessment, and implementation of effective HIV-1 intervention and prevention strategies.