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Biomedical subjects

R Willis

Publications and source records attributed to R Willis.

At least 19 recordsLinked to original sources
PubMed2005

The Biomolecular Interaction Network Database and related tools 2005 update.

The Biomolecular Interaction Network Database (BIND) (http://bind.ca) archives biomolecular interaction, reaction, complex and pathway information. Our aim is to curate the details about molecular interactions that arise from published experimental research and to provide this information, as well as tools to enable data analysis, freely to researchers worldwide. BIND data are curated into a comprehensive machine-readable archive of computable information and provides users with methods to discover interactions and molecular mechanisms. BIND has worked to develop new methods for visualization that amplify the underlying annotation of genes and proteins to facilitate the study of molecular interaction networks. BIND has maintained an open database policy since its inception in 1999. Data growth has proceeded at a tremendous rate, approaching over 100 000 records. New services provided include a new BIND Query and Submission interface, a Standard Object Access Protocol service and the Small Molecule Interaction Database (http://smid.blueprint.org) that allows users to determine probable small molecule binding sites of new sequences and examine conserved binding residues.

Animals↗
PubMed2004

Advanced electronics for the CTF MEG system.

Development of the CTF MEG system has been advanced with the introduction of a computer processing cluster between the data acquisition electronics and the host computer. The advent of fast processors, memory, and network interfaces has made this innovation feasible for large data streams at high sampling rates. We have implemented tasks including anti-alias filter, sample rate decimation, higher gradient balancing, crosstalk correction, and optional filters with a cluster consisting of 4 dual Intel Xeon processors operating on up to 275 channel MEG systems at 12 kHz sample rate. The architecture is expandable with additional processors to implement advanced processing tasks which may include e.g., continuous head localization/motion correction, optional display filters, coherence calculations, or real time synthetic channels (via beamformer). We also describe an electronics configuration upgrade to provide operator console access to the peripheral interface features such as analog signal and trigger I/O. This allows remote location of the acoustically noisy electronics cabinet and fitting of the cabinet with doors for improved EMI shielding. Finally, we present the latest performance results available for the CTF 275 channel MEG system including an unshielded SEF (median nerve electrical stimulation) measurement enhanced by application of an adaptive beamformer technique (SAM) which allows recognition of the nominal 20-ms response in the unaveraged signal.

Cluster Analysis↗
PubMed2003

Effect of analogs with modified prenyl side chains on growth of serum deficient HL60 cells.

This study was organized by Professor Karl Folkers with the objective of finding derivatives of coenzyme Q which could be more effectively absorbed and would give better biomedical effects. In this series all the compounds are 2,3 dimethoxy, 5 methyl p benzoquinone with modified side chains in the 6 position. The modifications are primarily changes in chain length, unsaturation, methyl groups and addition of terminal phenyl groups. The test system evaluates the growth of serum deficient HL60, 3T3 and HeLa cells in the presence of coenzyme Q10 or coenzyme Q analogs. Short chain coenzyme Q homologues such as coenzyme Q2 give poor growth but compounds with saturated short aliphatic side chains from C10 to C18 produce good growth. Introduction of a single double bond at the 2' or 8' position in the aliphatic chain retains growth stimulation at low concentration but introduces inhibition at higher concentration. Introduction of a 3' methyl group in addition to the 2' enyl site in the side chain decreases the growth response and maintains inhibition. Addition of a terminal phenyl group to the side chain from C5 to C10 can produce analogs which give strong stimulation or strong inhibition of growth. The action of the analogs is in addition to the natural coenzyme Q in the cell and is not based on restoration of activity after depletion of normal coenzyme Q. The effects may be based on any of the sites in the cell where coenzyme Q functions. For example, coenzyme Q2 is known to decrease mitochondrial membrane potential whereas the analog with a 10C aliphatic side chain increases potential. Both of these compounds stimulate plasma membrane electron transport. Inhibition of apoptosis by coenzyme Q may also increase net cell proliferation and the 10C analog inhibits the permeability transition pore.

3T3 Cells↗
PubMed2003

Use of an implantable loop recorder to investigate syncope in a cat.

The Reveal is an implantable loop recorder. It is increasingly being used in humans for the diagnosis of unexplained syncope where it is believed that cardiac arrhythmias may play a role, and may have great potential for investigating syncope in veterinary patients. The purpose of this report is to describe the first use of the device in the diagnosis of unexplained syncope in a cat.

Animals↗
PubMed2001

Aortic body chemodectoma causing pulmonary oedema in a cat.

A seven-year-old male domestic shorthaired cat was presented with persistent dyspnoea. Thoracic radiography and echocardiography revealed pulmonary oedema and a mass at the base of the heart. At necropsy the mass was found to be an aortic body chemodectoma that had metastasised to the sternal lymph node. This is a rare tumour in the cat, the third reported case where there was evidence of metastasis, and only the second reported case where there was evidence of lymphocytic infiltration of the primary tumour. Pulmonary oedema is an unusual presentation of this tumour in the cat.

Animals↗
PubMed2001

Comparison of hepatitis C viral loads in patients with or without human immunodeficiency virus.

A better understanding of how human immunodeficiency virus (HIV) coinfection affects the course of hepatitis C virus (HCV) infection is required to select patients with HIV who would benefit from current HCV therapy. Between June 1996 and March 2000, HCV RNA levels were quantified for 1,279 patients at the Louisiana State University Health Sciences Center; 28 of these patients were coinfected with HIV. HCV loads were quantified by the Bayer branched-DNA assay with a lower limit of detection of 0.2 Meq/ml. We compared the median HCV RNA levels of for patients coinfected with HIV and HCV and patients infected only with HCV who were in the same age range (23 to 55 years). The median HCV load for the 28 patients coinfected with HCV and HIV (17.8 Meq/ml) was significantly greater (P < 0.05) than that for similarly aged patients infected only with HCV (6.1 Meq/ml). The HCV load did not correlate with age or sex for either group of patients. A significant (R = -0.4; P < 0.05) negative correlation was observed between HCV load and CD4 count in the coinfected group, for whom the CD4 counts at the time of HCV load analysis ranged from 6 to 1,773/mm(3). The increased HCV load in patients coinfected with HCV and HIV compared to that in patients infected only with HCV and the inverse relationship of the HCV load to the CD4 count indicate that immunosuppression results in decreased control of HCV replication. In addition, we report significantly higher HCV loads among coinfected African Americans than Caucasians.

AIDS-Related Opportunistic Infections↗
PubMed2000

Distribution of foliar formylated phloroglucinol derivatives amongst Eucalyptus species.

Formylated phloroglucinol compounds (FPCs) in Eucalyptus leaves are important determinants of feeding in marsupial folivores and have a wide range of other biological actions. We conducted a survey of the occurrence of formylated phloroglucinol compounds (euglobals, macrocarpals and sideroxylonals) in acetone-petrol extracts of 41 species of Eucalyptus from among seven informal subgenera growing on the East Coast of Australia. We used electrospray ionisation, Fourier transform ion cyclotron resonance mass spectrometry (ESI-FTMS) to search crude extracts of eucalypt leaves for molecular weights characteristic of FPC compounds. We found masses characteristic of reported FPCs in 27 of the 41 species examined. The most frequently identified group of compounds was the sideroxylonals. Notable was the lack of known FPCs in the informal subgenus Monocalyptus.

Journal Article↗
PubMed2000

Spontaneous laryngeal paralysis in four white-coated German shepherd dogs.

Four cases of spontaneous laryngeal paralysis in juvenile white-coated German shepherd dogs are described. The presenting signs were typical for laryngeal paralysis, with stridor present in all four cases. Laryngoscopy revealed bilateral laryngeal paralysis in three cases, and unilateral paralysis in one. Concurrent megaoesophagus was also identified in one dog. All dogs underwent surgical treatment for laryngeal paralysis. Euthanasia was performed in one case due to intractable regurgitation and aspiration pneumonia. A possible association with white coat colour is discussed.

Animals↗
PubMed1999

Ambient air particles: effects on cellular oxidant radical generation in relation to particulate elemental chemistry.

Epidemiologic studies have reported causal relationships between exposures to high concentrations of ambient air particles (AAP) and increased morbidity in individuals with underlying respiratory problems. Polymorphonuclear leukocytes (PMN) are frequently present in the airways of individuals exposed to particles. Upon particulate stimulation the PMN may release reactive oxygen species (ROS), which can result in tissue damage and injury. In this study a wide range of AAP samples from divergent sources (1, natural dust; 2, oil fly ash; 2, coal fly ash; 5, ambient air; and 1, carbon black) were analyzed for elemental content and solubility in relation to their ability to generate ROS. Elemental analyses were carried out in AAP and dH(2)O-washed AAP using energy dispersive x-ray fluorescence (XRF). Percent of sample mass accounted for by XRF-detectable elements was 1.2% (carbon black); 22-29% (natural dust and ambient air particles); 13-22% (oil fly ash particles); 28-49% (coal fly ash particles). The major proportion of elements in most of these particles were aluminosilicates and insoluble iron, except oil-derived fly ash particles in which soluble vanadium and nickel were in highest concentrations, consistent with particle acidity as measured in the supernatants. Human blood-derived monocytes and PMN were exposed to AAP and dH(2)O-washed particles, and generation of ROS was determined using luminol-enhanced chemiluminescence (LCL) assay. All the particles induced chemiluminescence response in the cells, except carbon black. The oxidant response of monocytes induced by AAP (with the exception of oil fly ash particles) was less than the response elicited by PMN. The LCL response of PMN in general increased with all washed particles, with oil fly ash (OFA) and one urban air particle showing statistically significant (p < 0. 05) differences between dH(2)O-washed and unwashed particles. The LCL activity in PMN induced by both particles and dH(2)O-washed particles was significantly correlated with the insoluble Si, Fe, Mn, Ti, and Co content of particles (p < 0.05). No relationship between LCL activity in PMN and soluble transition metals such as V, Cr, Ni, and Cu was noted. Pretreatment of the particles with a metal ion-chelator, deferoxamine, did not affect LCL in PMN, suggesting that metal ions are not related to the induction of LCL in PMN. Particulate S content and acidity of the particles as measured in the supernatants did not relate to LCL activity in PMN. These results point to the possibility that the insoluble constituents of the particles are related to LCL in PMN. Since some of these dusts are capable of depositing in the lungs and can cause infiltration of PMN, the ability to activate those cells may contribute to particulate toxicity.

Air Pollutants↗
PubMed1999

Clinical implications of the correlation between coenzyme Q10 and vitamin B6 status.

The endogenous biosynthesis of the quinone nucleus of coenzyme Q10 (CoQ10) from tyrosine is dependent on adequate vitamin B6 nutriture. Lowered blood and tissue levels of CoQ10 have been observed in a number of clinical conditions. Many of these clinical conditions are most prevalent among the elderly. Kalen et al. have shown that blood levels of CoQ10 decline with age. Similarly, Kant et al. have shown that indicators of vitamin B6 status also decline with age. Blood samples were collected from 29 patients who were not currently being supplemented with either CoQ10 or vitamin B6. Mean CoQ10 concentrations was 1.1 +/- 0.3 micrograms/ml of blood. Mean specific activities of EGOT was 0.30 +/- 0.13 mumol pyruvate/hr/10(8) erythrocytes and the mean percent saturation of EGOT with PLP was 78.2 +/- 13.9%. Means for all parameters were within normal ranges. Strong positive correlation was found between CoQ10 and the specific activity of EGOT (r = 0.5787, p < 0.001) and between CoQ10 and the percent saturation of EGOT with PLP (r = 0.4174, p < 0.024). Studies are currently in progress to determine the effect of supplementation with vitamin B6 of blood CoQ10 levels. It appears prudent to recommend that patients receiving supplemental CoQ10 be concurrently supplemented with vitamin B6 to provide for better endogenous synthesis of CoQ10 along with the exogenous CoQ10.

Aging↗
PubMed1997

Treatment of hypertrophic cardiomyopathy with coenzyme Q10.

Hypertrophic cardiomyopathy (HCM) is manifested by severe thickening of the left ventricle with significant diastolic dysfunction. Previous observations on the improvement in diastolic function and left ventricular wall thickness through the therapeutic administration of coenzyme Q10 (CoQ10) in patients with hypertensive heart disease prompted the investigation of its utility in HCM. Seven patients with HCM, six non-obstructive and one obstructive, were treated with an average of 200 mg/day of CoQ10 with mean treatment whole blood CoQ10 level of 2.9 micrograms/ml. Echocardiograms were obtained in all seven patients at baseline and again 3 or more months post-treatment. All patients noted improvement in symptoms of fatigue and dyspnea with no side effects noted. The mean interventricular septal thickness improved significantly from 1.51 +/- 0.17 cm to 1.14 +/- 0.13 cm, a 24% reduction (P < 0.002). The mean posterior wall thickness improved significantly from 1.37 +/- 0.13 cm to 1.01 +/- 0.15 cm, a 26% reduction (P < 0.005). Mitral valve inflow slope by pulsed wave Doppler (EF slope) showed a non-significant trend towards improvement, 1.55 +/- 0.49 m/sec2 to 2.58 +/- 1.18 m/sec2 (P < 0.08). The one patient with subaortic obstruction showed an improvement in resting pressure gradient after CoQ10 treatment (70 mmHg to 30 mmHg).

Aged↗
PubMed1997

[Granulomatous colitis associated with diverticular disease. Report of a case].

We report the case of a 71 years old lady with clinical and radiological evidence of colonic obstruction due to diverticulosis. A segmentary resection of the sigmoid colon was performed and the diagnosis of diverticulosis and Crohn's disease was made in the surgical specimen. The patient is doing well and no further extension of the colonic granulomatosis has been found 8 months after surgery. In spite of the great frequency of diverticulosis in the elderly its association with Crohn's disease is quite uncommon. This is probably due to the infrequency of colonic Crohn's disease in this population, particularly of the segmentary type. A few cases of segmentary colonic Crohn's disease that were cured after resection have been published. Even though the postoperative period of our patient is too short for making a good prognosis. Crohn's disease is a chronic relapsing disease and frequency of recurrences is closely related with long term evolution.

Aged↗
PubMed1994

Usefulness of coenzyme Q10 in clinical cardiology: a long-term study.

Over an eight year period (1985-1993), we treated 424 patients with various forms of cardiovascular disease by adding coenzyme Q10 (CoQ10) to their medical regimens. Doses of CoQ10 ranged from 75 to 600 mg/day by mouth (average 242 mg). Treatment was primarily guided by the patient's clinical response. In many instances, CoQ10 levels were employed with the aim of producing a whole blood level greater than or equal to 2.10 micrograms/ml (average 2.92 micrograms/ml, n = 297). Patients were followed for an average of 17.8 months, with a total accumulation of 632 patient years. Eleven patients were omitted from this study: 10 due to non-compliance and one who experienced nausea. Eighteen deaths occurred during the study period with 10 attributable to cardiac causes. Patients were divided into six diagnostic categories: ischemic cardiomyopathy (ICM), dilated cardiomyopathy (DCM), primary diastolic dysfunction (PDD), hypertension (HTN), mitral valve prolapse (MVP) and valvular heart disease (VHD). For the entire group and for each diagnostic category, we evaluated clinical response according to the New York Heart Association (NYHA) functional scale, and found significant improvement. Of 424 patients, 58 per cent improved by one NYHA class, 28% by two classes and 1.2% by three classes. A statistically significant improvement in myocardial function was documented using the following echocardiographic parameters: left ventricular wall thickness, mitral valve inflow slope and fractional shortening. Before treatment with CoQ10, most patients were taking from one to five cardiac medications. During this study, overall medication requirements dropped considerably: 43% stopped between one and three drugs. Only 6% of the patients required the addition of one drug. No apparent side effects from CoQ10 treatment were noted other than a single case of transient nausea. In conclusion, CoQ10 is a safe and effective adjunctive treatment for a broad range of cardiovascular diseases, producing gratifying clinical responses while easing the medical and financial burden of multidrug therapy.

Cardiomyopathy, Dilated↗
PubMed1994

Treatment of essential hypertension with coenzyme Q10.

A total of 109 patients with symptomatic essential hypertension presenting to a private cardiology practice were observed after the addition of CoQ10 (average dose, 225 mg/day by mouth) to their existing antihypertensive drug regimen. In 80 per cent of patients, the diagnosis of essential hypertension was established for a year or more prior to starting CoQ10 (average 9.2 years). Only one patient was dropped from analysis due to noncompliance. The dosage of CoQ10 was not fixed and was adjusted according to clinical response and blood CoQ10 levels. Our aim was to attain blood levels greater than 2.0 micrograms/ml (average 3.02 micrograms/ml on CoQ10). Patients were followed closely with frequent clinic visits to record blood pressure and clinical status and make necessary adjustments in drug therapy. Echocardiograms were obtained at baseline in 88% of patients and both at baseline and during treatment in 39% of patients. A definite and gradual improvement in functional status was observed with the concomitant need to gradually decrease antihypertensive drug therapy within the first one to six months. Thereafter, clinical status and cardiovascular drug requirements stabilized with a significantly improved systolic and diastolic blood pressure. Overall New York Heart Association (NYHA) functional class improved from a mean of 2.40 to 1.36 (P < 0.001) and 51% of patients came completely off of between one and three antihypertensive drugs at an average of 4.4 months after starting CoQ10. Only 3% of patients required the addition of one antihypertensive drug. In the 9.4% of patients with echocardiograms both before and during treatment, we observed a highly significant improvement in left ventricular wall thickness and diastolic function.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Serving the needs of donor families: the role of the critical care nurse.

The humanitarian act of donating organs has tremendous benefits not only for the transplant recipients but also for the family of the donor. The opportunity to provide some hope to a grief-stricken family that something positive can result from their tragedy is an important contribution that a critical care nurse can make. The nurse's participation in recognizing the possibility of organ donation for the family of a terminal patient can drastically reduce the national shortage of transplantable organs. The consent and organ recovery process is a complex one, and a team approach by the nurse, physician, OPO coordinator, and other hospital staff members is necessary. Ultimately, the success of the effort is determined by the family's positive response to give the "Gift of Life."

Adolescent↗
PubMed1991

Long-term indomethacin therapy decreases fetal urine output and results in oligohydramnios.

Four quadrant quantitative amniotic fluid volume (length, width, and depth) was performed in six fetuses prior to and during indomethacin therapy for preterm labor in patients with normal amniotic fluid volume prior to therapy. The dose of indomethacin was 25 mg orally every 6 hours. One patient had to have the dose reduced to 25 mg every 12 hours due to constriction of the ductus arteriosus. Fetal urine output was determined prior to and during indomethacin therapy. The mean pretherapy amniotic fluid volume of 341.5 +/- 43.2 mm declined to 97 +/- 9.3 mm at the time of discontinuation of indomethacin for oligohydramnios. This occurred after 15 days of 25 mg indomethacin orally every 6 hours in four patients and after 28 days at 25 mg indomethacin every 12 hours in the remaining patient. Fetal urine output prior to and following indomethacin was 4.93 +/- 14 ml and 1.73 +/- 0.6 ml/hr, respectively. Prolonged indomethacin therapy results in decreased fetal urine output with resultant oligohydramnios and appears to be the major limiting factor aside from ductal constriction to long-term indomethacin therapy.

Adult↗
PubMed1991

Stapedectomy--past and present.

Surgical technics for bypassing ankylosis of the stapes in the management of otosclerosis gradually evolved; modifications were prompted by problems which were revealed by the ongoing audits carried out by earlier surgeons. Auditing of performance must remain an integral part of any otologist's work. The natural history of otosclerosis should be taken into account so that a patient may be fully informed of treatment alternatives available. Stapedectomy will remain a most effective operation which can be recommended with confidence, provided the surgeon has acquired the skill to perform it properly. It is now accepted that many ear, nose and throat surgeons are neither physically nor temperamentally capable of this task and should not perform stapedectomy.

Female↗