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Biomedical subjects

W Green

Publications and source records attributed to W Green.

At least 19 recordsLinked to original sources
PubMed2005

Small scale sanitation technologies.

Small scale systems can improve the sustainability of sanitation systems as they more easily close the water and nutrient loops. They also provide alternate solutions to centrally managed large scale infrastructures. Appropriate sanitation provision can improve the lives of people with inadequate sanitation through health benefits, reuse products as well as reduce ecological impacts. In the literature there seems to be no compilation of a wide range of available onsite sanitation systems around the world that encompasses black and greywater treatment plus stand-alone dry and urine separation toilet systems. Seventy technologies have been identified and classified according to the different waste source streams. Sub-classification based on major treatment methods included aerobic digestion, composting and vermicomposting, anaerobic digestion, sand/soil/peat filtration and constructed wetlands. Potential users or suppliers of sanitation systems can choose from wide range of technologies available and examine the different treatment principles used in the technologies. Sanitation systems need to be selected according to the local social, economic and environmental conditions and should aim to be sustainable.

Biodegradation, Environmental↗
PubMed2004

Effect of prior chemotherapy on hematopoietic stem cell mobilization.

A number of studies have suggested that prior chemotherapy correlates negatively with the efficiency of hematopoietic stem cell mobilization. However, little data exist with regard to the relative effects of the specific chemotherapeutic drug classes. We retrospectively reviewed the records of 201 consecutive patients with nonmyeloid malignancies undergoing CD34+ cell mobilization with chemotherapy+granulocyte colony-stimulating factor (G-CSF). The number of prior chemotherapy courses correlated negatively with the peripheral CD34+ cell concentration (pCD34) on the first day of collection (P<0.001). No significant correlation was found for age, gender, tumor primary, mobilization chemotherapy regimen, disease status, marrow involvement, prior radiation therapy, or dose and timing of G-CSF administration. When the number of courses of individual classes of chemotherapeutic agents was correlated with pCD34, only exposures to platinum compounds (P=0.001) and alkylating agents (P=0.01) were found to be independent negative predictive factors for pCD34. Within classes, DNA crosslinking agents and etoposide appeared possibly more damaging than DNA methylating agents and doxorubicin, respectively. None of the drug classes showed evidence of recovery. We conclude that exposure to chemotherapy, especially platinum compounds and alkylating agents, should be minimized prior to mobilization.

Age Factors↗
PubMed2000

The effects of aprotonin on platelets in vitro using whole blood flow cytometry.

UNLABELLED: We sought to evaluate the effects of aprotinin on the number and function of the platelet glycoprotein (GP) IIb-IIIa receptor and on the expression of P-selectin in vitro in order to gain insight into the potential mechanisms involved in the platelet-protective action of aprotinin during cardiopulmonary bypass. Aprotinin at 50 to 200 kallikrein inhibiting units/mL decreased the expression of activated GP IIb-IIIa complex in response to adenosine diphosphate or thrombin receptor activator peptide 6 in a dose-dependent manner in both citrated and heparinized whole blood experiments. Aprotinin inhibited adenosine diphosphate-induced platelet aggregation, but it exhibited no effect on the expression of GP IIIa and P-selectin. These results indicate that aprotinin interferes with the platelet fibrinogen receptor function during pharmacological activation. Reduced aggregability and platelet adhesion to fibrinogen adsorbed to synthetic surfaces in the presence of aprotinin may prevent platelet consumption during clinical cardiopulmonary bypass. This in vitro study demonstrates that aprotinin decreases the agonist-induced expression of activated GP IIb-IIIa receptors that play a major role in platelet aggregation and adhesion to biomaterial surfaces. IMPLICATIONS: This in vitro study demonstrates that aprotinin decreases the agonist-induced expression of activated glycoprotein IIb-IIIa receptors that play a major role in platelet aggregation and adhesion to biomaterial surfaces.

Adenosine Diphosphate↗
PubMed1999

Fibrinogen fragments and platelet dysfunction in uremia.

BACKGROUND: The uremic state is characterized by subnormal platelet aggregation. Fibrinogen fragments, usually absent in normal human blood, but present in uremic plasma, may play a role in uremic platelet dysfunction. METHODS: To examine this hypothesis, we investigated the availability and function of fibrinogen receptors [glycoprotein (GP) IIb-IIIa] on uremic and normal platelets, as well as the effect of fragments obtained from chymotrypsin digestion of human fibrinogen on normal platelets. The availability of fibrinogen receptors was examined using anti-GP IIb-IIIa antibodies and flow cytometry, whereas receptor function was assessed by the receptor's ability to mediate fibrinogen binding and platelet aggregation. RESULTS: Platelet aggregation and the availability of GP IIb-IIIa were lower in uremic patients when compared with normal controls. Flow cytometric analysis showed that fibrinogen fragments decreased the binding of anti-CD61, an activation-independent anti-GP IIIa monoclonal antibody, to resting normal platelets. These fragments also reduced the binding of PAC-1, an activation-dependent anti-GP IIb-IIIa monoclonal antibody, to adenosine diphosphate (ADP)-activated normal platelets. In addition, the binding of radiolabeled fibrinogen to activated normal platelets and platelet aggregation in response to ADP were both decreased by fibrinogen fragments. CONCLUSIONS: These findings suggest that fibrinogen fragments impair platelet function by occupying fibrinogen receptors prior to cell activation, thus preventing the binding of intact fibrinogen to platelets after subsequent stimulation. These observations also suggest a plausible mechanism by which endogenous fibrinogen fragments present in uremic plasma may contribute to platelet dysfunction.

Adenosine Diphosphate↗
PubMed1998

Cyclandelate in the management of tinnitus: a randomized, placebo-controlled study.

Cyclandelate is a vasodilating agent that, like papaverine, acts directly on the smooth muscles of blood vessels. The drug has been used primarily as an adjunctive treatment for various peripheral vascular diseases; some studies advocate its use for treating ischemic cerebrovascular disease. Early nonrandomized and uncontrolled studies suggest that cyclandelate is efficacious in treating tinnitus. Recent personal communications regarding cyclandelate's effectiveness in treating tinnitus prompted this study. Fifty-nine adult patients with constant tinnitus for more than 1 year were randomly selected for this prospective, placebo-controlled, double-blind study with a treatment period of 3 months. Audiometric testing with tinnitus pitch and loudness matching was performed before initiation of treatment and at the end of treatment, and frequent questionnaire evaluations were performed during the treatment period. Four patients in the cyclandelate group and three in the placebo group reported a subjective reduction in the loudness of their tinnitus. Audiologic testing before and after treatment showed no significant changes in tinnitus pitch or loudness. Although cyclandelate treatment was beneficial for some patients and the decrease in subjective loudness scoring was significant for the cyclandelate group, the impact of its effect did not appear to warrant its continued use by those patients. A significant percentage of patients could not tolerate the drug because of side effects.

Acoustic Impedance Tests↗
PubMed1998

Tissue distribution of hantavirus antigen in naturally infected humans and deer mice.

The Sin Nombre virus (SNV) is the etiologic agent of hantavirus pulmonary syndrome in humans but does not cause disease in chronically infected deer mice (Peromyscus maniculatus), the natural host. In this study, murine antiserum raised against recombinant SNV nucleocapsid protein was utilized to localize viral antigen immunohistochemically in tissues from both humans (n = 20; 11 positive, 9 negative) and deer mice (n = 6; 4 positive, 2 negative). Viral infection status was confirmed by Western blot or reverse transcriptase-polymerase chain reaction. SNV antigen was detected in pulmonary and cardiac endothelium in both species, but positive cells in deer mice were rare. Other deer mouse tissues, including kidney, were negative; in contrast, vascular elements of several tissues from infected humans were positive, with strong staining of renal endothelium. The paucity of positive cells in chronically infected mice suggests a low virus burden compared with that of acutely infected humans.

Animals↗
PubMed1998

Pulmonary complications of HIV infection: autopsy findings.

STUDY OBJECTIVES: To describe the pulmonary complications in patients with HIV infection, and the changes in the incidence of these complications over a 12-year period. DESIGN: Retrospective review of autopsy records. SETTING: Two university-affiliated medical centers. PATIENTS: We studied autopsy findings from 233 patients with HIV infection who died between 1985 and 1996. Demographic data, risk factors for HIV infection, and the lengths of hospital stay were obtained. The histologic and microbiological findings of the respiratory system, and the extrapulmonary organ involvement by Kaposi's sarcoma (KS), Pneumocystis carinii, Mycobacterium tuberculosis, and Mycobacterium avium complex were reviewed. RESULTS: Ninety-two percent of the patients were black and 75% were male. The two most common identified risk factors for HIV infection were homosexuality (34%) and injection drug use (27%). Bacterial pneumonia was the most frequent pulmonary complication (42%). The two most common causes of bacterial pneumonia were Pseudomonas aeruginosa and Staphylococcus aureus. P carinii pneumonia (PCP) was found in 24%, with extrapulmonary involvement in 13%. Pulmonary mycobacterial infections were seen in 33%, with multiple extrapulmonary involvement. The most common site affected by KS was the lung. Of all pulmonary complications, only the incidence of PCP decreased over the 12-year period. CONCLUSIONS: Recognizing the high incidence rate of bacterial pneumonia, the high frequency of pulmonary KS and the not uncommon occurrence of extrapulmonary P carinii infection in patients with HIV helps in improving their care.

AIDS-Related Opportunistic Infections↗
PubMed1997

The Beige/Chediak-Higashi syndrome gene encodes a widely expressed cytosolic protein.

The human autosomal recessive disorder Chediak-Higashi syndrome and its murine homologue beige are associated with the formation of giant lysosomes that cluster near the perinuclear region of cells. We prepared a polyclonal antiserum against a glutathione S-transferase-Beige fusion protein and demonstrated by Western analysis that the beige gene encodes a protein of 400 kDa that is expressed in cultured murine fibroblasts as well as most mouse tissues. The protein was not detected in either cultured fibroblasts or mouse tissues from two different beige mutants. Cultured fibroblasts transformed with multiple copies of yeast artificial chromosomes that contain the full-length beige gene showed much higher levels of Beige protein than either wild type fibroblasts or mouse tissues. Subcellular fractionation experiments demonstrated that the Beige protein was cytosolic and, under the conditions of isolation, had no measurable membrane association. Cultured mouse fibroblasts in which the Beige protein was overexpressed had smaller than normal lysosomes that were more peripherally distributed than in control cells. These findings, coupled with earlier published results, suggest that the Beige protein regulates lysosomal fission.

Animals↗
PubMed1997

Detection of high-grade cervical dysplasia: impact of age and Bethesda system terminology.

Pap smear, colposcopy, and biopsy results were collected from 1988-1993 at a group of family planning clinics. Positive predictive values and likelihood ratios were calculated for diagnosis of high-grade lesions based on age and Pap smear results. One thousand and forty-seven colposcopies were logged; 771 had a biopsy or endocervical curettage. Seventy-nine (10%) were high-grade lesions. If only human papillomavirus (HPV) was reported on the Pap smear, the likelihood of a high-grade biopsy was lowest (positive predictive value, 4.5%; likelihood ratio, 0.4). Women under age 25 were less likely to have high-grade biopsies (positive predictive value, 7.3%; likelihood ratio 0.7). Repeat Pap smears for atypical cells of undetermined significance (ASCUS) and low grade squamous intra-epithelial lesion (LGSIL) showing only HPV in women under age 30 would have reduced the immediate colposcopy rate by 60% and delayed diagnosis by 23% of high-grade lesions. Consideration of patient age and whether HPV is the only Pap smear finding may reduce referral for immediate colposcopy.

Adult↗
PubMed1997

Effects of anesthetic technique on side effects associated with fentanyl Oralet premedication.

STUDY OBJECTIVES: To evaluate the efficacy of 5 to 10 micrograms/kg of oral transmucosal fentanyl citrate (OTFC) as an anesthetic premedication, and to determine whether propofol induction reduces postoperative nausea and vomiting (PONV) in pediatric patients premedicated with OTFC undergoing outpatient surgery. DESIGN: Prospective, randomized, double-blinded study. SETTINGS: University of Michigan Health Care Systems and University of Arizona. PARTICIPANTS: 62 ASA physical status I and II children aged 4 to 14 years (8.9 +/- 0.5 years). INTERVENTIONS: Subjects were randomly assigned to one of four groups: (1) OTFC premedication and halothane induction; (2) OTFC premedication and propofol induction; (3) placebo premedication and halothane induction; and (4) placebo premedication and propofol induction. OTFC or placebo was administered 30 minutes prior to induction, and activity (sedation), apprehension, and cooperation scores were recorded before, at 15 and 30 minutes after study drug, and on induction. All perioperative adverse events were recorded. MEASUREMENTS AND MAIN RESULTS: Children who received OTFC became drowsier and had a significant change from baseline in combined activity, apprehension, and cooperation scores, whereas those who received placebo became less cooperative at induction. Patients who received OTFC experienced more adverse events overall (p < 0.001) than patients who received placebo. Additionally, OTFC patients experienced more vomiting (p < 0.001) and pruritus (p = 0.049) than controls. The incidence of PONV in patients who received OTFC and halothane induction was 50%, compared to 30% in patients receiving OTFC and a propofol induction (p = NS). CONCLUSIONS: OTFC in doses of 5 to 10 micrograms/kg was effective in producing sedation and facilitating cooperation with induction; however, it was associated with significant PONV in our study. Although propofol induction did not significantly reduce PONV in our study, further study with a larger sample, and with propofol as the sole anesthetic, may be warranted.

Administration, Oral↗
PubMed1997

Health evaluation of black-faced impala (Aepyceros melampus petersi) using blood chemistry and serology.

As part of ongoing ecological studies of black-faced impala (Aepyceros melampus petersi) in northern Namibia, blood samples were collected and analyzed from 26 animals captured for translocation in 1992. All animals appeared to be in good condition and no abnormality was noted during physical examination. Serum chemistry and mineral levels were measured and correlated with the results of bacterial and viral serology and were within the normal ranges for domestic ruminants. Antibody titers for infectious bovine rhinotracheitis and bovine viral diarrhea were detected. Serological tests for bluetongue, foot-and-mouth disease, rinderpest, parainfluenza 3, brucellosis, leptospirosis, and anaplasmosis were negative. Significant differences in disease prevalence were not found between sexes.

Animals↗
PubMed1996

Evidence of chronic inflammation in retina excised after relaxing retinotomy for anterior proliferative vitreoretinopathy.

BACKGROUND: Epiretinal membranes from eyes with proliferative vitreoretinopathy (PVR) frequently express molecules associated with chronic inflammation. To investigate the extent to which inflammation may compromise the detached retina, we determined the expression of inflammatory molecules in anterior retina removed after relaxing retinotomy for retinal detachment complicated by anterior PVR. METHODS: Surgical retinal specimens were studied immunohistochemically for the distribution of the vascular cell adhesion molecules VCAM, E-selectin, P-selectin, ICAM and PECAM and for the presence of the cytokine TNF alpha and of T lymphocytes (CD3-positive cells), macrophages (CD68-positive cells) and HLA-DR molecules. The findings were compared with those in control cadaveric retina. RESULTS: Aberrant expression of ICAM-1 was observed in four of nine retinal specimens from eyes with PVR, whereas its expression in control retinas was confined to the external limiting membrane and ganglion cell layers. PECAM was observed in seven of nine surgical retinal specimens and in four of five controls. E-selectin and P-selectin were expressed within the luminal aspects of four of nine retinal specimens from eyes with PVR, and VCAM was present in three of nine surgical specimens investigated. All cadaveric control retinas were negative for E-selectin and VCAM, whilst one was positive for P-selectin. Staining for TNF alpha was observed within luminal aspects and walls of retinal vessels from eight of nine surgical specimens, but was not seen in any of the cadaveric controls. T lymphocytes and cells expressing the macrophage marker CD68 were identified in two and seven of nine diseased retinas respectively, but not in any of the controls. Cells staining for HLA-DR were observed in eight of nine surgical retinal specimens and in three of five controls. CONCLUSION: The present findings indicate that retina from eyes with advanced PVR may itself be subject to inflammatory changes, and indicate that the PVR process is not limited to retinal membranes, but involves a more widespread distribution of inflammation than is generally appreciated.

Chronic Disease↗
PubMed1996

A randomised prospective study of outpatient haemodilution for central retinal vein obstruction.

PURPOSE: Central retinal vein obstruction (CRVO) has significant visual morbidity. We prospectively evaluated an outpatient haemodilution (HD) regimen for CRVO. METHODS: We recruited 59 patients with CRVO of less than three months' duration and visual acuity (VA) worse than or equal to 6/9.5. Thirty patients underwent HD (packed cell volume of <0.35, 12 weeks); there were 29 controls and follow-up was for six months. RESULTS: Incidence rates for VA improvement (P = 0.708) and rubeosis iridis (P = 0.619) between the two groups were not different. The incidence rate of VA deterioration was 5.315 times higher with HD (P = 0.035, Cox Proportional analysis). CONCLUSION: This data does not support the previous studies on haemodilution.

Adult↗
PubMed1996

The venous closing pressure in central retinal vein obstruction.

OBJECTIVE: To assess the rate of change in the central retinal venous closing pressure in central retinal vein obstruction over time, and its relationship to visual acuity improvement and the development of rubeosis iridis. METHODS: Fifty patients presenting with central retinal vein obstruction of less than three months' duration, between the ages of 40 and 80 years, were reviewed prospectively. The central retinal venous closing pressure was measured by digital ocular compression. Patients were discharged from the study after the six-month visit. RESULTS: All patients had elevated venous closing pressure at presentation, whereas at six months only 24 patients had persistent elevation. Of 16 patients with lowering of the venous closing pressure within four months of onset of central retinal vein obstruction, 11 (69%) had two or more lines of visual acuity improvement. Only two of 10 patients (20%) developing lowering of the venous closing pressure thereafter had visual improvement. No patient developed rubeosis iridis after the venous closing pressure lowered. CONCLUSION: The central retinal venous closing pressure is raised in central retinal vein obstruction to about central retinal arterial diastolic pressure, and is its pathognomonic sign. This sign is easily elicited via digital pressure on the eyelid, and has prognostic significance for visual acuity improvement and the development of rubeosis iridis.

Adult↗
PubMed1996

Distribution of TNF alpha and its reactive vascular adhesion molecules in fibrovascular membranes of proliferative diabetic retinopathy.

AIMS: This study investigated the presence of the cytokine tumour necrosis factor alpha (TNF alpha) and the vascular adhesion glycoproteins ICAM-1, VCAM-1, E-selectin, P-selectin, and PECAM within fibrovascular membranes of eyes with proliferative diabetic retinopathy (PDR). METHODS: The presence of these molecules was determined by immunohistochemical staining using monoclonal antibodies and the APAAP technique. RESULTS: Staining for TNF alpha was observed on the retinal vascular endothelium of five of 12 specimens, on infiltrating cells within all membranes, and on the extracellular matrix of nine specimens. This staining wa abolished by absorption of the monoclonal antibody with human recombinant TNF alpha. Likewise, ICAM-1 staining was given by infiltrating cells and extracellular matrix of nine membranes and by the endothelium of three of the specimens. VCAM-1, E-selectin, and P-selectin staining was observed on the vascular endothelium of 5/12, 4/12, and 3/12 epiretinal membranes respectively. PECAM was expressed by the endothelium of 4/12 specimens, by infiltrating cells of 8/12 membranes, and also by the extracellular matrix of two of the specimens. CONCLUSION: The widespread distribution of TNF alpha and the nature of the adhesion molecules expressed by vascular endothelial cells in PDR membranes suggest that local activation of TNF alpha and enhanced expression of vascular cell adhesion molecules may play an important role in the development of the proliferative phase of diabetic retinopathy.

Adult↗
PubMed1995

The effect of changes in house dust mite allergen exposure on the severity of asthma.

To measure the association between changes in house dust mite (HDM) allergen Der p I exposure and changes in the severity of asthma, we re-analysed data from a clinical trial in which 34 HDM-allergic subjects with asthma (18 women, mean age 35 years) were followed for between 3 and 12 months. The concentration of Der p I in fine dust from the bed, the bedroom floor and the living room floor was measured at 3-monthly intervals along with assessment of subjects' spirometric function and airway hyperresponsiveness (AHR, measured by histamine inhalation test). Daily symptom scores, morning peak expiratory flow rate and peak flow variability were measured throughout the study period. The mean Der p I concentration in the bed at baseline was 25.4 micrograms/g (95% CI: 15.8-40.6). During the course of the study large within-subject fluctuations were observed in allergen concentrations and in the measurements of the severity of asthma. Changes in allergen concentration in the bed were significantly correlated with changes in AHR (P = 0.003) and symptom score (P = 0.04). Changes in allergen concentration in the living room floor were correlated with changes in symptom scores (P = 0.01). Although these correlations were significant the magnitude of the effect was relatively modest. We conclude that a large reduction in HDM allergen concentration, particularly in the bed, results in a modest reduction in AHR and improvement in symptoms in HDM-allergic subjects with asthma.

Adolescent↗