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Biomedical subjects

C Chandler

Publications and source records attributed to C Chandler.

At least 19 recordsLinked to original sources

The diagnostic significance of an assay for 'total' hepatitis C core antigen.

A measurable serological response to hepatitis C infection is delayed on average until 70 days after infection. In addition, it may not occur in some immunocompromised people. Detection of free hepatitis C (HCV) core antigen in blood has enabled diagnosis in the pre-seroconversion period. The ability to detect 'total' HCV core antigen, both free and antibody bound, would widen its use for confirming anti-HCV antibody positive patients and monitoring a therapeutic response. This study has evaluated a prototype 'total' HCV core antigen immunoassay. Sera from 145 HCV negative blood donors gave a mean value of 54.9 (+/-46.2) pg/ml based on recombinant antigen standards. Using these figures, the HCV core antigen cut-off was set as 200 pg/ml. Two hundred blood donors sera with indeterminant (a single-band on recombinant immunoblot assay) HCV antibody statuses gave fully concordant HCV core antigen results compared to their polymerase chain reactions (PCRs)--three positive, and 197 negative. HCV core antigen and PCR results were compared for 59 sera from 19 HCV positive liver disease patients. The HCV core antigen results were in complete agreement with their PCRs for the nine patients always PCR positive and the three continuously negative. For six patients on antiviral therapy whose qualitative PCRs changed from positive to negative, the HCV core antigen results paralleled the PCR results. The only discrepant results were from one patient whose PCR results went from negative to positive. 'Total' HCV core antigen testing will greatly improve the scope of diagnostic tests for hepatitis C.

Hepacivirus↗

Agronomic use of biotechnologically processed grape wastes.

Grape waste was composted by biodegradation and subsequently used as an organic fertilizer for 20 day-corn. Combinations of recently compressed grape waste and hen droppings (10% w/w) were prepared to study the activating effect of hen droppings and the effect of aeration on the composting process. The final hydrogen potential (pH), %C, %N and C/N ratio, indicated an adequate development of the bioprocess. Satisfactory results were observed when the products were applied at several doses (1,000-4,000 kg/ ha) as a soil conditioner for corn seed germination in greenhouses. Only the addition of hen droppings had a significant effect (P < 0.05) on corn dry matter (14% increase). A dose of 3000 kg/ha was considered as optimal and was used supplemented with triple superphosphate (TSP) in agronomic trials. All the treatments produced greater corn dry matter (P < 0.05) than the chemical industrial fertilizer used as a control (0.52-0.71 g/pot for the organic fertilizers vs 0.45 g/pot for the control). Anaerobic conditions and hen droppings addition significantly produced (P < 0.05) higher corn dry matter.

Biodegradation, Environmental↗

Enhancing personal wellness in counselor trainees using biofeedback: an exploratory study.

The purpose of this study was to explore whether biofeedback-assisted relaxation training could reduce stress-related symptoms and enhance personal well-being in a group of counselor trainees enrolled in a basic counseling skills course. Treatment participants received ten sessions of weekly biofeedback-assisted relaxation training, whereas the control participants received no intervention. The treatment group showed, significant improvements in several symptom areas measured by the Symptom Checklist 90-Revised: physical complaints (Somatization), personal inadequacy (Interpersonal Sensitivity), confused thinking or alienation or both (Psychoticism), and the overall number and severity of symptoms (Global Severity Index and Positive Symptom Total). The control participants showed no significant improvements in any symptom areas. Biofeedback-assisted relaxation was shown to be an effective stress-reducing intervention for counselor trainees, which resulted in a greater sense of personal well-being.

Adult↗

Extraction and validation of a lower limb HAQ by comparison with objective measurement of ambulatory activity.

OBJECTIVES: Both the Health Assessment Questionnaire (HAQ) and the measurement of spontaneous ambulatory activity are measures that can be used to evaluate disability in RA. METHODS: A cross sectional survey was conducted of 105 RA patients where the HAQ was compared with ambulatory activity from the Numact monitor. Rank correlation was used to evaluate the relationships between activity and the complete and individual sections of the HAQ. RESULTS: Correlation of activity with total HAQ produced significant results (r= -0.29 to -0.48). Correlation with individual sections showed the strongest association with "Hygiene", followed by "Activities", and "Walking". A lower limb HAQ was devised using these and the dressing and rising items. CONCLUSIONS: HAQ and recorded activity measure different but related aspects of disability. Activity should be used if the ability to quantify the result outweighs the extra effort involved in the study.

Activities of Daily Living↗

Porcelain gallbladder is not associated with gallbladder carcinoma.

The surgical management of porcelain gallbladder is based on studies performed in 1931 and 1962, which indicated a correlation between porcelain gallbladder and carcinoma. We sought to evaluate the characteristics of patients with porcelain gallbladder and the risk for gallbladder carcinoma. The medical records of 10,741 cholecystectomies performed between 1955 and 1998 were reviewed and recorded. The pathology slides were evaluated for evidence of calcification and gallbladder carcinoma. Fifteen (0.14%) of 10,741 specimens were porcelain gallbladders. Ten patients (67%) had symptoms suggestive of biliary colic or cholecystitis. Five (33%) were asymptomatic and diagnosed incidentally. All specimens demonstrated chronic cholecystitis and partial calcification of the gallbladder wall. Nine (60%) had cholelithiasis. None had gallbladder carcinoma by recent review of pathologic material. During this same period 88 (0.82%) patients had gallbladder carcinoma, none of which showed calcification of the wall. This report represents the largest modern review of porcelain gallbladders. No carcinoma was identified among patients with porcelain gallbladder. In addition no patient with gallbladder carcinoma had calcified gallbladder. With a better understanding of the natural history of the porcelain gallbladder the current management of these patients may change.

Adult↗

Intestinal ischemia and the gut-liver axis: an in vitro model.

BACKGROUND: Sustained intestinal ischemic injury often leads to shock and multiorgan failure, mediated in part by a cytokine cascade. Animal models have also identified a central role of Kupffer cells in amplification of cytokines following intestinal ischemia. To better understand this gut-liver axis, we developed an in vitro model. MATERIALS AND METHODS: Kupffer cells were isolated from rat livers by arabinogalactan gradient ultracentrifugation and adherence purification. Cells were grown in RPMI medium in 5% CO(2). Rat intestinal epithelial cells, IEC-6, were cultured under normoxic or anoxic (90% N(2), 10% CO(2)) conditions for 2, 12, and 24 h. Kupffer cells were then grown in the conditioned medium of the IEC-6 cultures. After 24 h, the medium was replaced with fresh medium. This final Kupffer cell supernatant was tested for tumor necrosis factor alpha and interleukin-6 production by ELISA. Trypan blue exclusion was performed to assess cell viability. RESULTS: Intestinal and Kupffer cells remained viable during the experimental time. Production of both tumor necrosis factor alpha and interleukin-6 by Kupffer cells increased with increasing ischemia time of the intestinal cells. CONCLUSIONS: Consistent with animal studies of intestinal ischemia, this study found an increase in cytokine production by Kupffer cells following hypoxia of intestinal cells. This in vitro model offers a new tool to study the expression of cytokines, proteins, and messengers involved in the cascade of events that follow intestinal ischemia.

Animals↗

Provider gender preference in obstetrics and gynecology: a military population.

OBJECTIVE: This study evaluates patient reasons and preferences for gender selection of their obstetrician-gynecologist. METHODS: A written survey was given to patients attending a military obstetrics and gynecology clinic (N = 203). Mean age was 36 years, with 69% of patients between 20 and 40 years. Caucasian (52%) and African American (34%) were the most common races. RESULTS: Overall, 52% of patients preferred a female practitioner, 4% preferred males, and gender did not matter for 44%. Experience and reputation were the most important factors in 93% of all patient provider selections. Only 10% of patients felt that gender was the most important factor, and 35% ranked gender as one of the top two factors. CONCLUSION: Although a majority of our study population preferred female obstetrician-gynecologist providers, experience and reputation were more frequently cited than gender as the most important factors in selecting a provider. Patients felt that female physicians understand their problems better.

Adolescent↗

Prevalence of back, neck and shoulder problems in the inner city: implications for the provision of physiotherapy services in primary healthcare.

BACKGROUND AND PURPOSE: More general practitioners are offering physiotherapy services within primary healthcare; however, this provision may result in increased demand. Resource allocation, based on previous patterns of consultation for musculoskeletal conditions, may be inadequate since the need for treatment in the community may not have been met in the past. Therefore the aim of this study was to determine the prevalence of back, neck and shoulder problems that had restricted normal activity for more than one week during the last year and which health professionals (if any) patients had consulted about their symptoms. METHOD: A postal survey of 2400 adult patients selected at random from four general practices in Newcastle upon Tyne (600 from each practice). RESULTS: A total of 1546 questionnaires were returned, a 64% response rate. Overall, 40% of respondants reported having at least one back, neck and/or shoulder problem. Back problems were most common (30%), followed by those with neck (21%) and shoulder (20%) problems. Approximately one-third of those with problems consulted no one, a further third consulted a general practitioner and only one in six consulted a physiotherapist. CONCLUSIONS: There is a high prevalence of substantial back, neck and shoulder problems in the community and thus a wider provision of physiotherapy services within primary healthcare may be required to manage the considerable levels of potentially unmet need.

Adolescent↗

Spontaneous ambulatory activity as a quantifiable outcome measure for rheumatoid arthritis.

OBJECTIVE: To validate the objective monitoring of ambulatory activity as an outcome measure for rheumatoid arthritis (RA). METHODS: We have compared ambulatory activity to a range of currently favoured outcome measures, ranging from subjective opinions to X-ray damage, in a population of 93 RA sufferers. RESULTS: Correlations were stronger with measures of joint damage and disability, and less strong with measures of disease activity. Sensitivity to change was good. Three different interventions were compared for the quantity of the response, and the results agree with clinical experience, with steroid injection of the knee and use of non-steroidal anti-inflammatory drugs (NSAIDs) having a similar response and the provision of surgical shoes producing a more modest increase in ambulation. CONCLUSION: The measurement of ambulatory activity has validity for RA assessment. It provides different but related data to the currently used measures. It is objective, relevant, quantifiable and of unlimited scale. It could be used to quantify interventions aimed at increasing ambulation, in carefully constructed studies.

Arthritis, Rheumatoid↗

Direct injection of 90Y MoAbs into glioma tumor resection cavities leads to limited diffusion of the radioimmunoconjugates into normal brain parenchyma: a model to estimate absorbed radiation dose.

PURPOSE: Previously we have demonstrated that radioimmunoconjugates can be injected into glioma resection cavities to deliver a boost of radiation to the cavity edge with little toxicity to the normal brain. In the mathematical models we have previously published to assist in the development of this strategy we assumed that antibody remains associated with the cavity edge and no diffusion occurs. However, moderate diffusion might be beneficial while, if this were excessive, it would decrease the therapeutic index markedly. METHODS AND MATERIALS: Selected individuals with relapsed malignant glioma underwent further surgical debulking; 90Y MoAb radioimmunotherapy; and open biopsy to determine the extent to which the conjugate diffuses from the cavity edge. Samples from these patients were taken in radial tracts and the corrected activity in each sample was plotted against distance from the cavity wall to determine appropriate diffusion constants. RESULTS: Our data indicates that diffusion of radioimmunoconjugate from the edge of a glioma resection cavity appears to be an exponential process. The mean Ro for each patients data set ranged from 0.48-0.63 (overall mean 0.6) cm. A dosimetric model was developed that translates these measurements into estimates of radiation dose. Applying the clinical data to this model indicates that, in each patient, the peak dose is delivered 0.16-0.18 cm below the cavity margin, and the mean dose at 2 cm deep is 5.3% (4.4-5.8%) of the peak. CONCLUSION: The model described can be used to translate diffusion constants measured by any method into estimates of absorbed radiation dose. Assuming similar diffusion kinetics, it can also be used to predict the dose deposited if alternative radionuclides are linked to MoAb, although the effect of dose rate should also be considered. In the future, it may be possible to manipulate diffusion by using either different antibodies or antibody fragments for intracavity radioimmunotherapy. Before this can be done, however, further data are needed and a noninvasive approach to measuring diffusion would clearly be optimal.

Antibodies, Monoclonal↗

Dose escalation with repeated intrathecal injections of 131I-labelled MAbs for the treatment of central nervous system malignancies.

We have previously demonstrated a 33% response rate in patients with primitive neurectodermal tumours after the direct injection of 131I-monoclonal antibodies (MAbs) into the cerebrospinal fluid (CSF). Dose-limiting toxicity is myelosuppression due to the passage of the radioimmunoconjugate from the CSF to the blood compartment. This occurs at doses of 2220 MBq of 131I-MAb and above, although this is not seen in all patients studied and appears to be related to the degree of prior therapy received. Rather than attempting to improve the efficacy of this approach to the treatment of disseminated disease within the CSF compartment by dose escalation and haemopoietic rescue, we have explored the possibility of repeatedly administering the radioimmunoconjugate. Eight patients were recruited to the study, two of whom received two and six of whom received three injections of 131I-MAb. After repeated administration of 131I-MAb pharmacokinetic data revealed that, with one exception, the radioimmunoconjugate cleared from the CSF compartment with similar kinetics, while its residence time in the blood decreased with each injection. This was due to the development of an anti-mouse Ig response in the blood. Clearance of 131I-MAb from the ventricular CSF appears to be independent of the presence of an anti-mouse Ig response in this compartment. The differential clearance of the radioimmunoconjugate from the ventricular CSF and from the blood results in a marked increase in the therapeutic index that can be achieved. Up to 5920 MBq of 131I-MAb was administered as the third injection of radioimmunoconjugate and combined doses of up to 12,500 MBq were given without either haematological or neurological toxicity. These data illustrate that dose escalation and thus an increase in the dose rate delivered to tumour cells within the CSF is possible if ways are found to reduce the residence time of the radioimmunoconjugate in the blood compartment. Suggestions as to how this can best be achieved are reviewed in detail.

Adolescent↗

Spontaneous ambulatory activity as a quantifiable outcome measure for osteoarthritis of the knee.

OBJECTIVE: Quantifiable outcome measures for disabling diseases such as osteoarthritis (OA) of the knee are necessary in order to compare the impact of different interventions competing for financial resources. Current subjective and questionnaire data are not satisfactory for such study. In this study, we examine the potential of the direct measurement of ambulatory activity as such a measure. POPULATION: Patients with X-ray evidence of OA of the knee recruited to studies of anti-inflammatory agents (n = 29). Patients with OA of the knee awaiting knee replacement surgery (n = 28). METHODS: Comparison of various standard measures with total energy output data from an activity monitor. RESULTS: Spearman rho correlations of ambulatory energy output (number of steps x average amplitude of steps) correlated with other measures. Correlation with physician's opinion was greater than with patient's opinion (r = 0.4 and 0.2, respectively). There was no correlation with visual analogue pain scale or OA severity index. Correlation with scales of the Nottingham Health Profile questionnaire were not significant either for mobility (r = - 0.15) or for pain (r = - 0.13). There was, however, a significant correlation between poor sleep and increased activity (r = 0.34, P < 0.05). Correlation with Kellgren X-ray grade was significant (r = - 0.45, P = 0.01). Patients recruited to anti-inflammatory studies were 69% more active than those awaiting replacement surgery. CONCLUSION: The monitoring of ambulatory activity shows some construct and discriminant validity, and is worthy of further study.

Energy Metabolism↗

Safety of completion thyroidectomy for multicentric carcinoma.

The role of completion thyroidectomy after lobectomy for well-differentiated thyroid carcinoma remains controversial. The purpose of the present study is to compare the relative safety of a one-stage versus a two-stage approach in the management of thyroid cancer. Thirty consecutive patients with thyroid carcinoma were studied. In 14 patients, frozen-section diagnosis of carcinoma allowed total thyroidectomy at the initial operation. In 16 patients, carcinoma was found only on permanent section; thus, completion thyroidectomy was undertaken as a second stage. Transient hypocalcemia occurred in one patient in each group (one-stage, 7%; two-stage, 6%). There was one unilateral recurrent nerve paresis in the one-stage group and none in the two-stage group. We conclude that a two-stage procedure is a safe and effective approach for the treatment of thyroid cancer and can be employed in those instances in which the diagnosis of malignancy is insecure at the initial operation.

Adenocarcinoma, Follicular↗

Ambulatory activity as an objective and quantifiable measure of nonsteroidal therapy.

OBJECTIVE: To quantify any increase in short term spontaneous ambulatory activity resulting from the use of nonsteroidal antiinflammatory drugs (NSAID) in patients with rheumatoid arthritis (RA). METHODS: Double blind placebo controlled crossover study of 8 women with RA using conventional assessments and the Numact activity monitor. RESULTS: Patients' ambulatory activity was 50% greater during NSAID treatment compared to placebo treatment. Effect size calculated at 0.62, suggesting good sensitivity to change. The increased activity occurred late morning. CONCLUSION: Spontaneous ambulatory activity is an objective and relevant measure of disability.

Adult↗

Pharmacists on a primary care team at a Veterans Affairs medical center.

The role of pharmacists on a primary care team in the VA Chicago Health Care System--Lakeside Division is described. In 1990 the Veterans Affairs Lakeside Medical Center (now called the VA Chicago Health Care System--Lakeside Division) implemented the "Firm" system to improve the quality of patient care. This system split the original primary care clinics into three identical but smaller groups, or Firms. Each Firm provides three types of care: longitudinal care (ongoing care with a primary care physician), interim care (frequent care and close patient monitoring between primary physician visits), and un-scheduled care (acute care for complaints that may require immediate attention). Each Firm has a care team composed of physicians, a pharmacist, nurses, and other health care personnel. The pharmacist assists with interim care and, in conjunction with Firm physicians, is involved in follow-up and monitoring of drug therapy and identification of new problems. Originally it was expected that pharmacists would care for 30-40% of interim care patients, but Firm pharmacists have assisted in providing care to over 50% of these patients (plus 4% of un-scheduled care patients). The pharmacists have received high ratings from the internal medicine resident staff. Pharmacists on multidisciplinary care teams provided primary care to more than half of outpatient veterans in need of health care between regularly scheduled appointments.

Chicago↗