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Biomedical subjects

D Campbell

Publications and source records attributed to D Campbell.

At least 73 records · Page 4Linked to original sources

Electroencephalogram and repetitive transcranial magnetic stimulation.

Scalp recordings of the electroencephalogram (EEG) have been used in association with repetitive transcranial magnetic stimulation (rTMS) investigations as a safety measure in monitoring ongoing EEG activity and as a neurophysiologic tool in examining the specific effects induced by the magnetic stimulus on the EEG or evoked potentials (EPs). Medline review on the use of EEG or EPs with rTMS reveals that this area has been largely unexplored. Limited available studies attest to the potential for studies combining EEG/EPs and rTMS to be useful in further elucidating the normal brain physiology. Herein, we report on our experience with continuous EEG sampling combined with rTMS in patients with major depression (n = 14), schizophrenia (n = 7), and obsessive-compulsive disorder (n = 5). Our data support the practice of using continuous EEG monitoring when the stimulation parameters fall outside established safety guidelines.

Brain Mapping↗

A subunit vaccine candidate region of the Entamoeba histolytica galactose-adherence lectin promotes interleukin-12 gene transcription and protein production in human macrophages.

The cysteine-rich region of the 170-kDa subunit galactose-adherence lectin (Gal-lectin) of Entamoeba histolytica is a subunit vaccine candidate and a protective antigen in the gerbil model of amebiasis. Macrophage-mediated immunity is important for protection against E. histolytica and is activated by Th1 cytokines. As Th1 differentiation is promoted by IL-12, we investigated what portion of the Gal-lectin could stimulate IL-12 in human THP-1 macrophages. Native Gal-lactin stimulated IL-12 p40 / p35 mRNA expression in a dose- and time-dependent manner as measured by reverse transcriptase-PCR. Human immune serum and Gal-lectin mAb inhibition studies identified amino acids (aa) 596 - 998 as immunogenic and containing the IL-12 inducing domain. IFN-gamma priming augmented Gal-lectin-induced IL-12 mRNA expression independent of TNF-alpha and IL-1beta, and was required for IL-12 p70 protein production from macrophages and human peripheral blood mononuclear cells. Gal-lectin plus IFN-gamma stimulated IL-12 p40 and p35 gene transcription with stable mRNA transcripts and a differential requirement for protein synthesis. These results suggest that aa 596 - 998 of the Gal-lectin can confer Th1-mediated protection against amebiasis through IL-12 induction.

Animals↗

Allergen immunotherapy: novel approaches in the management of allergic diseases and asthma.

Currently available pharmacotherapies for allergic diseases and asthma, which are serious public health problems, are aimed primarily at neutralizing effector molecules and inflammatory mediators such as histamine and leukotrienes or at inhibiting the function of inflammatory cells such as eosinophils and Th2 lymphocytes. While this approach is effective in controlling symptoms, these therapies have a limited capacity to alter the natural course of allergic diseases and asthma, and discontinuation of medications results in the redevelopment of symptoms on reexposure to the offending allergens. In contrast, immune-based allergen immunotherapies modify and correct the underlying pathological immune responses in allergy and asthma in an antigen-specific manner. These immunotherapies replicate the regulatory processes that occur in nonallergic individuals and allow patients to tolerate exposure to allergens. Current and future methodologies for immunotherapy involve immunization with allergen, modified allergen, peptides of allergen, cDNA of allergen, with adjuvants, including immunostimulatory DNA sequences, cytokines, and bacterial products such as Listeria monocytogenes. This form of therapy can provide a long-lasting cure for allergic diseases without the need for continuous therapeutic intervention and without causing generalized immunosuppression or immune augmentation.

Allergens↗

Nitric oxide and high frequency jet ventilation in a patient with bilateral bronchopleural fistulae and ARDS.

PURPOSE: To describe a method of delivering nitric oxide during high frequency jet ventilation. CLINICAL FEATURES: A 63-yr-old man underwent reduction pneumoplasty for bullous emphysema. Postoperatively, ventilation was inadequate, secondary to bilateral high output bronchopleural fistulae. High frequency jet ventilation was initiated and achieved adequate ventilation (pH>7.2). Over the following 24 hr, progressive hypoxemia (SaO2 <86%) developed along with the acute respiratory distress syndrome. Nitric oxide was delivered by continuous flow at the patient Y-connector during combined high frequency jet and conventional ventilation (two conventional low volume breaths/minute). Substantial improvement in oxygenation (FiO2 0.8 0.5, SaO2 >92%) was noted initially and was sustained over 72 hr. Subsequently, the patient was weaned to conventional ventilation without difficulty. Mechanical ventilation was discontinued on postoperative day sixteen. CONCLUSION: The simultaneous use of nitric oxide and high-frequency jet ventilation was used safely and effectively in this patient as a method of support for acute respiratory distress syndrome with co-existing large bilateral bronchopleural fistulae.

Bronchial Fistula↗

Conditional ETDT analysis of the human leukocyte antigen region in type 1 diabetes.

Several studies have indicated that additional genes in the major histocompatibility complex (MHC) region, other than the class II genes HLA-DQB1 and -DRB1 (the IDDM1 locus), may contribute to susceptibility and resistance to type 1 diabetes. The relative magnitude of these non- DR/DQ effects is uncertain and their map location is unknown owing to the extraordinary linkage disequilibrium that extends over the 3.5 Mb of the MHC. The homozygous parent test has been proposed as a method for detection of additional risk factors conditional on HLA-DQB1 and -DRB1. However, this method is inefficient since it uses only parents homozygous for the primary disease locus, the DQB1-DRB1 haplotype. To overcome this limitation, Conditional ETDT was used in the present report to test for association conditional on the DQB1-DRB1 haplotype, thereby allowing all parents to be included in the analysis. First, we confirm in UK and Sardinian type 1 diabetic families that allelic variation at HLA-DRB1 has a very significant effect on the association of DQB1 and vice versa. The Conditional ETDT was then applied to the HLA TNF (tumour necrosis factor) region and microsatellite marker D6S273 region, both of which have been reported to contribute to IDDM1 independent of the HLA-DQB1-DRB1 genes. We found no evidence for a major role for either of these two regions in IDDM1.

Adolescent↗

Similarities in the disturbances in cortical information processing in alcoholism and aging: a pilot evoked potential study.

OBJECTIVE: To examine the hypothesis that chronic alcohol use causes accelerated aging of the brain. METHODS: The auditory evoked potentials (EPs) were compared in three groups of 10 subjects each: (a) middle-aged individuals meeting DSM-IV criteria for alcohol dependence, (b) age- and gender-matched group of healthy individuals, and (c) an older (>65 years) group of gender-matched healthy individuals. Multiple levels of cortical information processing were examined using EPs. Early stages of information processing, related to sensory gating and stimulus classification (P50, N100/P200), were studied using a paired-click paradigm. Later stages of information processing associated with memory upgrading and identification of novel stimuli (P300) were studied using an oddball paradigm. RESULTS: The amplitude and latency of the P300 of the alcoholic patients and the older healthy subjects differed significantly from those of the younger healthy group. Both groups showed changes that have been reported in association with aging. A tendency towards decreased sensory gating in later stages of information processing was noted in the aged healthy individuals. CONCLUSIONS: These data suggest that alcohol dependence may accelerate the aging process. The tendency towards a sensory gating deficit during the attentive phase of information processing in older healthy subjects requires further investigation because it may be a marker for an increased proneness to developing psychotic symptoms in that group.

Adult↗

Transvaginal ultrasound examination of women with and without pelvic venous congestion.

AIM: To determine if transvaginal ultrasound, including power Doppler examination, can distinguish between women with and without pelvic congestion. MATERIALS AND METHODS: Thirty-six women with pelvic congestion were prospectively examined using transvaginal ultrasonography and standard uterine and ovarian measurements made. Additionally, planimetric measurements of each ovary were taken using an image analysis program to determine the cross-sectional area of ovarian stroma and follicles, if any. Power Doppler images of adnexal vessels were obtained and planimetric estimates of surface area calculated. A congestion score was assigned to each patient, based on vein number, diameter and morphology on grey-scale scanning. Identical measurements were obtained from 19 asymptomatic women and results compared. RESULTS: There was no significant difference between women with pelvic congestion and controls with respect to power Doppler or grey-scale images of adnexal vessels, or congestion score. However, women with pelvic congestion had significantly larger and multicystic ovaries when compared to controls. CONCLUSIONS: Transvaginal ultrasound measurements of adnexal vasculature, including power Doppler measurements, cannot reliably distinguish women with pelvic congestion from controls. However, ultrasound may remain useful for diagnosis of pelvic congestion, predominantly because it is able to visualize multi-cystic ovaries in these patients.

Adult↗

New York State universal newborn hearing screening demonstration project: inpatient outcome measures.

OBJECTIVE: To evaluate the feasibility of universal newborn hearing screening by examining inpatient outcome measures from 8 hospitals located in geographically diverse areas of New York State over a 3-yr period. DESIGN: Funding was provided by the New York State Department of Health to implement predischarge hearing screening programs in the neonatal intensive care units (NICUs) and well-baby nurseries (WBNs) of eight hospitals. Various screening protocols including transient evoked otoacoustic emissions alone or in combination with conventional auditory brain stem response or screening auditory brain stem response were implemented by each site. Measured outcomes included rate of misses, refusals, and fails. Results were analyzed as a function of year of operation, nursery type, and geographic location. RESULTS: Six out of eight hospitals successfully implemented universal hearing screening during the first year, and the remaining 2 hospitals implemented programs during the second year of the project. Over a period of 3 yr, 69,761 newborns were screened at the eight hospitals representing 96.9% of all live births. The overall fail rate (4.04%) combined with the miss rate (2.61%) resulted in 6.63% of infants referred for outpatient follow-up. Mean data indicated that inpatient outcome measures improved with year of operation, with most individual hospitals also showing improvements. Both fail and miss rates were higher in the NICU than in the WBN and for hospitals located in New York City than in other regions of the state. CONCLUSIONS: Inpatient outcome measures of a universal newborn hearing screening project, which involved multiple centers across geographically diverse regions of New York State, were acceptable in terms of successfully screening a high percentage of live births and attaining low refer rates for outpatient screening. This study adds to the growing body of literature supporting the feasibility of screening all newborns before hospital discharge.

Acoustic Stimulation↗

The New York State universal newborn hearing screening demonstration project: outpatient outcome measures.

OBJECTIVE: To investigate outpatient outcome measures of a multi-center, state-wide, universal newborn hearing screening project. DESIGN: Eight hospitals participated in a 3-yr, funded project. Each hospital designed its own protocol using common criteria for judging whether an infant passed a hearing screening. Infants were tested in the hospital, and those either failing the in-hospital screening or who were not tested in the hospital (missed) were asked to return 4 to 6 wk after hospital discharge for outpatient rescreening. Those infants failing the outpatient rescreening were referred for diagnostic auditory brain stem response testing. Each hospital used its own audiological equipment and criteria to determine whether a particular infant had a hearing loss. All data were collected and analyzed for individual hospitals, as well as totaled across all hospitals. Data were analyzed in terms of year of program operation, nursery type, and geographic region. RESULTS: Seventy-two percent of infants who failed the in-hospital screening returned for outpatient testing. The percentage of in-hospital fails returning for retesting was significantly higher than the percentage of in-hospital misses returning for retesting. The percentage of infants returning for retesting increased with successive years of program operation. Some differences were noted in the percentage of infants returning for retesting among hospitals and geographic regions of the state. Some differences in outpatient outcome measures also were noted between infants originally born into the neonatal intensive care unit (NICU) and the well-baby nursery (WBN). The percentage of infants from the NICU who returned for retesting was slightly higher than that for infants from the WBN. The percentage of infants from the WBN passing the outpatient rescreening was higher than that for the NICU infants. The overall prevalence of hearing loss was 1.96/1000, with that in the NICU being 8/1000 and that in the WBN being 0.9/1000. Positive predictive value for permanent hearing loss based on inpatient screening was approximately 4% and based on outpatient rescreening was approximately 22%. CONCLUSIONS: Several outpatient outcome measures changed with successive years of program operation, suggesting that programs improve over time. Also, some outpatient outcome measures differ between NICU and WBN populations. The differences noted across regions of the state in the percentage of infants returning for outpatient retesting require further research to determine whether differences are due to demographic and/or procedural differences.

Ambulatory Care↗

The New York State universal newborn hearing screening demonstration project: ages of hearing loss identification, hearing aid fitting, and enrollment in early intervention.

OBJECTIVE: To determine the ages of hearing loss identification, hearing aid fitting, and enrollment in early intervention through a multi-center, state-wide universal newborn hearing screening project. DESIGN: Universal newborn hearing screening was conducted at eight hospitals across New York State. All infants who did not bilaterally pass hearing screening before discharge were recalled for outpatient retesting. Inpatient screening and outpatient rescreening were done with transient evoked otoacoustic emissions and/or auditory brain stem response testing. Diagnostic testing was performed with age appropriate tests, auditory brain stem response and/or visual reinforcement audiometry. Infants diagnosed with permanent hearing loss were considered for hearing aids and early intervention. Ages of hearing loss identification, hearing aid fitting, and enrollment in early intervention were investigated regarding nursery type, risk status, unilateral versus bilateral hearing loss, loss type, loss severity, and state regions. RESULTS: The prevalence of infants diagnosed with permanent hearing loss was 2.0/1000 (85 of 43,311). Of the 85 infants with hearing loss, 61% were from neonatal intensive care units (NICUs) and 67% were at risk for hearing loss. Of the 36 infants fitted with hearing aids, 58% were from NICUs and 78% were at risk for hearing loss. The median age at identification and enrollment in early intervention was 3 mo. Median age at hearing aid fitting was 7.5 mo. Median ages at identification were less for infants from the well-baby nurseries (WBNs) than for the NICU infants and for infants with severe/profound than for infants with mild/moderate hearing loss, but were similar for not-at-risk and at-risk infants. Median ages at hearing aid fitting were less for well babies than for NICU infants, for not-at-risk infants than for at-risk infants, and for infants with severe/ profound hearing loss than for infants with mild/ moderate hearing loss. However, median ages at early intervention enrollment were similar for nursery types, risk status, and severity of hearing loss. CONCLUSIONS: Early ages of hearing loss identification, hearing aid fitting, and enrollment in early intervention can be achieved for infants from NICUs and WBNs and for infants at risk and not at risk for hearing loss in a large multi-center universal newborn hearing screening program.

Age Factors↗

New York State universal newborn hearing screening demonstration project: effects of screening protocol on inpatient outcome measures.

OBJECTIVE: To examine differences among various test protocols on the fail rate at hospital discharge for infants in the well-baby nursery (WBN) and neonatal intensive care unit (NICU) who received hearing screening through a universal newborn hearing screening demonstration project. DESIGN: The outcomes of several screening protocols were examined. Two technologies were used: transient evoked otoacoustic emissions (TEOAEs) alone or in combination with the auditory brain stem response (ABR). The performance of test protocols in both nurseries within eight hospitals was examined over a 2- to 3-yr period. In the WBN, six hospitals used a screening protocol of TEOAE technology first followed by an ABR (automated or conventional) technology screening for newborns who referred on TEOAE screening. Two hospitals used TEOAE only in the WBN. Seven hospitals used screening protocols in the NICU that used a combination of TEOAE and ABR technologies (TEOAE technology administered first or second, before or after TEOAE, or TEOAE and ABR tests on all infants). Only one hospital used TEOAE technology exclusively for hearing screening. RESULTS: Significant differences among screening protocols were found across hospitals in the first, second, and third years of the program. The combination of TEOAE technology and ABR technology (a two-technology screening protocol) resulted in a significantly lower fail rate at hospital discharge than the use of a single-technology (TEOAE). Fail rates at discharge were twice as high using the one-technology protocol versus two-technology protocol, even when the best outcomes from program year 3 were considered exclusively. Results of two-technology versus one-technology protocols were similar in the NICU. Use of a second technology for screening TEOAE fails significantly reduced every hospital that used the protocol's fail rate at discharge. CONCLUSIONS: A two-technology screening protocol resulted in significantly lower fail rates at hospital discharge in both the WBN and NICU nurseries than use of a single-technology (TEOAE) hearing screening protocol.

Evoked Potentials, Auditory, Brain Stem↗

Bioterrorism: challenges and opportunities for local health departments.

The emerging threat of bioterrorism will significantly impact local health departments. If a bioterrorism attack occurs, local medical and public health personnel will have the primary role of recognition and response. Federal assistance and training to deal with bioterrorism have been directed to 120 of our largest cities. Despite progress, much needs to be done. The public health approach to bioterrorism must begin with the development of local and state plans developed by public health, emergency response, and law enforcement communities, which must work together closely if an epidemic is to be detected in a timely manner.

Biological Warfare↗

The PROSTALAC functional spacer in two-stage revision for infected knee replacements. Prosthesis of antibiotic-loaded acrylic cement.

The PROSTALAC functional spacer is made of antibiotic-loaded acrylic cement but has a small metal-on-polythene articular surface. We have used it as an interim spacer in two-stage exchange arthroplasty for infected total knee replacement. PROSTALAC allows continuous rehabilitation between stages as it maintains good alignment and stability of the knee and a reasonable range of movement. It also helps to maintain the soft-tissue planes, which facilitates the second-stage procedure. We reviewed 45 consecutive patients, treated over a period of nine years. The mean follow-up was for 48 months (20 to 112). At final review, there was no evidence of infection in 41 patients (91%); only one had a recurrent infection with the same organism. There was improvement in the Hospital for Special Surgery knee score between stages and at final review. The range of movement was maintained between stages. Complications were primarily related to the extensor mechanism and stability of the knee between stages. Both of these problems decreased with refinement of the design of the implant. The rate of cure of the infection in our patients was similar to that using other methods. Movement of the knee does not appear to hinder control of infection.

Adult↗

Depression, hopelessness, and the desire for life-saving treatments among elderly medically ill veterans.

During a serious medical illness, several factors, including perceived quality of life, social support, functional disability, severity of illness, and presence of depressive symptoms, influence desire for life-saving treatments such as cardiopulmonary resuscitation (CPR), mechanical ventilation, tube feeding, and intravenous fluids. The authors examined the influence of depression and hopelessness on preferences for life- saving treatment in older, medically ill male patients in the medical service of a Veterans Administration Medical Center. Subjects with high levels of hopelessness desired less life-saving treatment during their current illness; they were at least five times more likely to refuse CPR if required during the current hospitalization. This effect remained statistically significant after removing confounds of race, education, and religiosity. The diagnosis of major depression did not significantly influence the desire for life-saving treatment. Our findings suggest that psychiatrists should assess patients for severity of hopelessness when evaluating decision-making capacity in the context of intervention refusal.

Acute Disease↗