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Biomedical subjects

J Jackson

Publications and source records attributed to J Jackson.

At least 145 records · Page 8Linked to original sources
PubMed1995

Depletion of gentamicin in the milk of Holstein cows after single and repeated intramammary and parenteral treatments.

Twenty-four healthy Holstein cows, 2.72 +/- 0.64 (mean +/- SD) years old, weighing 603.96 +/- 73.22 kg (mean +/- SD), and representing various levels of milk production, were used to determine the depletion of gentamicin (GT) in milk. The cows had not received antibiotics or other drugs that could interfere with study for at least 60 days before the beginning of the investigation. The cows were divided into six groups (n = 4) and treated with single (treatments A, B and C) or repeated (treatments D, E and F) doses of GT. Cows were acclimated for 7 days before administration of GT and milked twice a day at 12-h intervals (06.00 hours, 18.00 hours) throughout the duration of the study. Control milk samples were obtained after the arrival of the cows and assayed to establish their GT free status. On day 1 of each treatment, a baseline milk sample was collected from the milk produced (06.00 hours) by each cow. A single dose of GT was administered intramammarily (A, i.m.m. left front quarter, 500 mg), intravenously (B, i.v., 5 mg/kg body weight) or intramuscularly (C, i.m., 5 mg/kg body weight). Cows in treatments D (i.m.m., 500 mg), E (i.v., 5 mg/kg body weight) and F (simultaneous i.m.m. 500 mg plus i.v. 5 mg/kg body weight) were treated twice a day for 5 consecutive days just after the morning and evening milkings. Milk samples from individual cows were collected every day after each milking during and after dosing until GT concentration in the milk was below the safe level of < or = 30 ng/mL. The concentration of GT in milk was determined by a high-performance liquid chromatographic procedure. Depletion of GT to a concentration < or = 30 ng/mL occurred at the seventh (84 h), third (36 h), third (36 h), eleventh (132 h) third (36 h) and nineteenth (228 h) post-dosing milking, for cows in treatments A, B, C, D, E and F respectively. The highest mean +/- SEM) concentrations of GT were 14 710 +/- 1213.89, 167.87 +/- 46.94 and 91.62 +/- 14.55 ng/mL measured in the first milking post dosing (12 h) for cows in treatment A, B and C respectively; for cows in treatments D, E and F, during the dosing period, they were 14067.50 +/- 2989.09, 446.07 +/- 100.92, and 22900 +/- 2843.66 ng/mL and occurred at the seventh, third and eighth milking respectively. Because GT is not approved for use in dairy cattle and because of the long depletion time associated with some possible treatments, illegal and extra-label use is likely to cause residues in milk.

Animals↗
PubMed1995

Evaluation of CK and CK-MB in alcohol abuse subjects with recent heavy consumption.

We analyzed CK and CK-MB levels over 24 h in 15 male subjects admitted for alcohol detoxification following recent heavy ingestion. None had clinical or electrocardiographic evidence of myocardial ischemia or infarction. The mean 0-hour serum alcohol level +/- SD was 342 +/- 101 mg/dl. CK levels were measured by Kodak Ektachem and Abbott IMx assays, and CK-MB levels were determined by these assays and the Hybritech isoenzyme test. In 36% of the patients elevated 0-hour CK levels by the IMx and Ektachem assays were observed. The CK levels measured every 8 h decreased so that by 24 h CK was elevated in 1 patient by the Ektachem assay and in 2 by the IMx assay. Only 1 patient (7%) had an elevated 0-hour CK-MB value by two of the three assays, and it is unclear whether the source was cardiac or extracardiac. We conclude that: (1) elevated CK levels are common in heavy alcohol use patients without evidence of myocardial ischemia; (2) CK values over the first 24 h are decremental, not rising and falling as is typical of myocardial infarction and (3) current isoenzyme immunoassays eliminate a cardiac cause for elevated CK in most of these patients. These findings may assist in the evaluation of alcoholic patients with chest pain.

Adult↗
PubMed1995

Catastrophic anti-phospholipid syndrome in the absence of IgG anti-cardiolipin antibodies.

The Catastrophic Anti-phospholipid Syndrome (CAPS) is a rare acute clinical syndrome associated with serum anti-phospholipid antibodies (aPL). It is rarely preceded by a precipitating event. It may occur as a primary event or be associated with auto-immune diseases. We report a fatal case occurring post-endoscopic retrograde cholangio-pancreatography (ERCP) in a patient with Systemic Lupus Erythematosus (SLE), positive lupus anticoagulant and negative IgG with positive IgM anti-cardiolipin titres. The diagnostic and therapeutic difficulties of such cases is addressed.

Adult↗
PubMed1995

In vivo evaluation of three acid-stable azalide compounds, L-701,677, L-708,299 and L-708,365 compared to erythromycin, azithromycin and clarithromycin.

L-701,677, L-708,299 and L-708,365 are novel azalide derivatives of erythromycin that exhibit improved acid stability over erythromycin, azithromycin and clarithromycin. The half-life in aqueous solution at pH = 2.1 of these compounds ranged from 0.3 hour for erythromycin to 16.2 hours for L-708,299. The rank order of half-life in acid solution from most to least stable was L-708,299 > L-701,677 > L-708,365 > azithromycin = clarithromycin > erythromycin. In a disseminated Streptococcus pyogenes mouse infection model, azithromycin and L-708,365 were slightly more efficacious than clarithromycin, L-701,677 and L-708,299; all 5 compounds being more active than erythromycin. In a Klebsiella pneumoniae pulmonary challenge mouse model, azithromycin, L-701,677, L-708,299 and L-708,365 were all equal in efficacy and at least four-fold more active than clarithromycin and erythromycin. Clarithromycin, L-708,365 and interestingly erythromycin, showed greater bacterial clearance than azithromycin, L-701,677 and L-708,299 in a localized infection model that measured clearance of Staphylococcus aureus from mouse thigh tissues. Our results indicate that L-701,677, L-708,299 and L-708,365 exhibit improved acid stability and were at least equally efficacious as presently marketed macrolide/azalide antibiotics.

Animals↗
PubMed1994

Habitually wandering patients.

BACKGROUND: Physicians are sometimes confronted with patients who gain admission to one hospital after another, sometimes referred to as "wandering patients." Little is known about the presenting symptoms of these patients, their use of hospital resources, or the costs of their medical care. We analyzed the demographic and clinical characteristics of wandering patients served by Department of Veterans Affairs medical centers (VAMCs). METHODS: For each patient they admit, all 159 hospitals in the Veterans Affairs medical system submit demographic and diagnostic information to a central data base at the Data Processing Center in Austin, Texas. We searched these records to identify patients who were admitted to four or more VAMCs within each year from fiscal year 1988 through 1992. Patients so identified in any one year were called "wanderers"; those identified in all five years were designated "habitual wanderers." RESULTS: We identified 1013 wanderers in 1988. The number gradually declined each year to 729 in 1993. In 1991 there were 810 wandering patients, who averaged about eight admissions per year and over 100 days of inpatient care; they accounted for about $26.5 million in costs for inpatient and outpatient care in that year. Only 35 patients wandered in all five years from 1988 through 1992. The most common discharge diagnoses of these 35 men were related to substance abuse (mostly alcoholism) and mental disorders. Their 2268 admissions and 7832 outpatient visits cost an estimated $6.5 million over the five-year period. CONCLUSIONS: Patients who are repeatedly admitted to different hospitals--wandering patients--accumulate high numbers of admissions, cause diagnostic confusion, and receive uncoordinated care. Because of the complexity of their disorders, such patients require case management on a regional or national basis.

Adult↗
PubMed1994

Novel karyotype in the Ullrich-Turner syndrome--45,X/46,X,r(X)/46,X, dic(X)--investigated with fluorescence in situ hybridization.

A 10-year-old girl with Ullrich-Turner syndrome was found to have the novel karyotype 45,X/46,X,r(X)(p11q11)/46,X,dic(X)(p11). Fluorescence in situ hybridization (FISH) with the alpha satellite X centromere probe established the origin of the small ring chromosome. Scanning a large number of cells by interphase FISH showed that the dicentric (X) was the least prevalent cell line. The common breakpoint of Xp11 suggests a sequence of errors as the mechanism whereby these 3 distinct cell lines have arisen.

Cells, Cultured↗
PubMed1994

Familial polyarteritis nodosa.

Familial polyarteritis nodosa (PAN) is rare. We describe here two siblings who developed PAN 8 years apart. HLA typing showed that the affected family members shared a common haplotype with their unaffected mothers. Further study of the family history suggested the possibility of an inherited disorder of connective tissue predisposing to autoimmunity and aneurysm formation.

Adolescent↗
PubMed1994

Anatomical urinary stress incontinence in women with rheumatoid arthritis: its frequency and coping strategies.

OBJECTIVE: The objectives of this study were to develop a valid screening tool for anatomical urinary stress incontinence (AUSI), to use it to determine the frequency of AUSI in women with RA, and to identify the cognitive, behavioral, and psychological coping strategies used by these women to deal with incontinence. METHODS: A screening tool concerning AUSI was validated by comparing self-reported incidences of AUSI with clinical evaluation. Questionnaires regarding presence of AUSI and cognitive, behavioral, and psychological coping strategies were sent to 750 women clinically diagnosed with RA. RESULTS: Of the 262 respondents (35% response rate), 21% had characteristics of AUSI, a rate similar to general population studies. Coping strategies varied depending on whether the women were at home or away from home and whether the women were alone or with others. CONCLUSIONS: There is a need for women with incontinence and the health care workers who serve them to be educated about AUSI and its treatments.

Adaptation, Psychological↗
PubMed1994

Prenatal diagnosis and post-mortem study of a fetus with mosaic trisomy 14 due to a dic(14)(p11).

Amniocentesis at 17 weeks' gestation revealed a mosaic karyotype--46,XX/46,XX,-14,+dic(14)(p11). No abnormalities were detected on ultrasound. Growth and placentation were normal. The fetus was examined after termination of pregnancy and micrognathia and pulmonary hyperlobation were the only abnormalities detected. Several tissues were set up for cytogenetics, including fetal skin, kidney, ovary, and placenta. The diagnosis was confirmed by these studies. The level of mosaicism varied between tissues, with the trisomy 14 cell line highest in amniotic fluid.

Adult↗
PubMed1994

Reality of glove use and handwashing in a community hospital.

BACKGROUND: Since the advent of universal precautions and body substance isolation, few studies have examined the relationship between glove use and handwashing. METHODS: During a 5-month period in 1991, 477 structured observations were conducted on 19 patients care units at a community teaching hospital during each of three shifts. Patient care contacts were defined as either high level or low level according to potential for blood or body fluid contact. RESULTS: Health care workers were potentially exposed to body fluids (high-level contact) on 152 occasions. Eighty-eight percent of all high-level contacts were limited to the hands; 47% of these contacts occurred during the night shift. Handwashing occurred after 32% of high-level contacts. Health-care workers wore gloves in 57% of high-level contacts. Rates of handwashing and glove use varied markedly among patient care units. Correct handwashing (> or = 9 seconds) occurred after 20% of contacts when health care workers wore gloves but after only 3% of high-level contacts when gloves were not used (p = 0.004). CONCLUSIONS: Despite universal precautions or body substance isolation, educational efforts, and written policies, rates of handwashing and glove use are inadequate in cases of potential blood and body fluid contact. The perceived need for gloves may encourage handwashing.

Blood↗
PubMed1994

Tissue plasminogen activator for hepatic vein thrombosis in paroxysmal nocturnal haemoglobinuria.

Paroxysmal nocturnal haemoglobinuria (PNH) is an acquired clonal disorder thought to arise in a multipotent haemopoietic stem cell. A distinct clinical feature is a tendency to thrombosis, with a particular predilection for the hepatic veins (Budd-Chiari syndrome). We report here on two patients with PNH who developed hepatic vein thrombosis (HVT) and who were treated with tissue plasminogen activator (t-PA). Both patients had a marked clinical and radiological improvement following the t-PA treatment and remain well over 2 years and 6 years after the treatment. This method of thrombolysis for HVT occurring in PNH has only been reported in two previous patients with limited follow-up. We suggest that this therapy is a useful first-line treatment for PNH patients who develop HVT.

Adult↗
PubMed1994

Disposition and bioavailability of neomycin in Holstein calves.

The disposition and absorption kinetics of neomycin were studied in healthy ruminating dairy calves (n = 6), approximately 3-months-old. The calves were treated with single intravenous (i.v.) (12 mg/kg), intramuscular (i.m.) (24 mg/kg), oral (p.o.) (96 mg/kg) and repeated p.o. (96 mg/kg, b.i.d., 15 1/2 days) doses of neomycin. A 3-week rest period was allowed between treatments A and B, and B and C. Baseline and serial venous blood samples were collected from each calf. Plasma concentrations of neomycin were determined by a high performance liquid chromatography procedure. The resulting data were evaluated by using compartmental pharmacokinetic models and nonlinear least squares regression analysis. The mean of some selected parameters were t1/2 lambda 3 7.48 +/- 2.02 h, Clt = 0.25 +/- 0.04 L/h/kg, Vd(ss) = 1.17 +/- 0.23 L/kg, and MRT = 4.63 +/- 0.87 h for the i.v. data and t1/2 = 11.5 +/- 3.8 h, MRTabs = 0.960 +/- 1.001 h, F = 127 +/- 35.2%, and Clt/F = 0.199 +/- 0.047 L/h/kg for the i.m. data, respectively. Only one calf absorbed neomycin to any significant degree (F = 0.0042) after a single p.o. dose. Selected mean parameters determined after repeated oral dosing were: F = 0.45 +/- 0.45%, Cmax = 0.26 +/- 0.37 microgram/ml, and tmax = 2.6 +/- 2.9 h. Terminal half-lives determined for the i.v. and i.m. treatments were considerably longer than those reported previously in the literature.

Animals↗
PubMed1994

Unproven treatment in childhood oncology--how far should paediatricians co-operate?

How should doctors respond to requests from parents of terminally ill children for unproven treatments to be tried? Here it is argued that doctors faced with difficult cases where (1) it is not obviously against a child's interests to undergo an unproven treatment and (2) provided the treatment does not draw extravagantly on NHS funds, it may be appropriate, though not necessarily obligatory, for doctors to comply. It is important to recognise that often there may not be 'the right response'--only alternative appropriate responses.

Brain Neoplasms↗