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J M Jensen

Publications and source records attributed to J M Jensen.

At least 37 records · Page 2Linked to original sources
PubMed1998

[A new method of 3-dimensional imaging of dose distribution in radiotherapy].

Beside the documentation it is the object of the graphical presentation of dose distribution in radiotherapy to clarify for better judgement. A three-dimensional graphical presentation could rise the understanding. Auto-stereographical presentation of isodoses opens the practicability for a three-dimensional view without the use of additional auxiliarities, such as stereoscope, or spectacles. This is shown by some isodose distribution charts (fixed field-, box-, multiple field- and rotation-technique, AL-treatment).

Dose Fractionation, Radiation↗
PubMed1997

Effects of xerosis and ageing on epidermal proliferation and differentiation.

The hallmarks of dry skin (xerosis) are scaliness and loss of elasticity. Decreased hydration and a disturbed lipid content of the stratum corneum are also well-known features. The frequency of dry skin increases with ageing. The aim of this study was to examine if these known features of dry skin are related to changes in epidermal proliferation and differentiation. In addition, age-related changes in normal and in dry skin were examined: 62 volunteers were divided by clinical grading and biophysical measurements into groups with young/normal, young/dry, aged/normal and aged/dry skin. Biopsy samples from the lower legs (most severe dryness) were examined by two-dimensional gel electrophoresis and by immunohistochemistry for epidermal proliferation, epidermal keratins and cornified envelope proteins. There was a slight increase in proliferation in both groups with dry skin compared with normal skin of the corresponding age. In aged/normal compared with young/normal skin there was a significant decrease in proliferation. However, epidermal proliferation was the same in aged/dry skin as in young/normal skin. For epidermal differentiation, an age-independent decrease of keratins K1 and K10 and an associated increase in the basal keratins K5 and K14 was detected in dry skin. There was also an age-independent premature expression of the cornified envelope protein involucrin. In contrast, loricrin expression was not influenced by dry skin conditions. In summary, epidermal proliferation was significantly decreased in aged/normal compared with young/normal skin. Dry skin showed significant changes in the epidermal expression of basal and differentiation-related keratins, and a premature expression of involucrin irrespective of age.

Adult↗
PubMed1997

Topical vitamin D3 derivatives impair the epidermal permeability barrier in normal mouse skin.

BACKGROUND: Calcipotriol, 1,25(OH)2D3 and 1,24(OH)2D3 are potent drugs for the treatment of psoriasis. It has recently been published that these compounds induce epidermal hyperproliferation in hairless mouse skin. OBJECTIVE: The aim of our study was to examine the effect of vitamin D3 derivatives on epidermal growth, keratinization and permeability barrier function in vivo. METHODS: Calcipotriol, 1,25(OH)2D3 and 1,24(OH)2D3 in isopropanol or in an ointment formula were applied to normal hairless mouse skin. Transepidermal water loss (TEWL), a marker of cutaneous barrier function, and epidermal proliferation were determined at different time points 0-264 h after treatment. In addition, light and electron microscopy studies were performed. RESULTS: A single treatment in solution led to a transient (2- to 3-fold) increase in TEWL after application of calcipotriol or 1,25(OH)2D3 and to a 3- to 6-fold increase in epidermal proliferation after application of each of the compounds. Repeated applications also resulted in an up to 3-fold increase in TEWL which persisted for 3 days after the end of the treatment. By light microscopy an increase in epidermal thickness was observed. There was no sign of inflammation. Electron microscopy studies showed the formation of a transitional cell zone as a sign of a premature keratinization. CONCLUSION: These results demonstrate that in normal mouse skin vitamin D3 and its analogues disrupt the epidermal permeability barrier by induction of epidermal proliferation and premature keratinization but without morphological signs of inflammation.

1-Propanol↗
PubMed1997

Pharmacokinetics of a single intravenous enrofloxacin dose in scimitar-horned oryx (Oryx dammah).

Based on a 1.3 mg/kg mean dosage determined by metabolic energy scaling, enrofloxacin pharmacokinetics of a single i.v. dose of enrofloxacin in five adult scimitar-horned oryx (Oryx dammah) were determined. Drug concentration versus time curves were best fit by residual analysis to a one-compartment open model with a maximum (mean +/- SD) serum concentration after distribution of 1.887 +/- 0.632 micrograms/ml and an elimination half-life of 41.2 +/- 27.5 min. Model-independent parameters were area under the curve (173.63 +/- 147.5 micrograms.min/ml), mean volume of distribution (steady state) (0.80 +/- 0.30 L/kg), clearance (12.07 +/- 7.12 ml/min/kg), and residence time (77.22 +/- 72.8 min). Mean serum enrofloxacin concentrations reached the recommended minimum inhibitory concentration (1.0 micrograms/ml). Drug concentrations remained above the minimum inhibitory concentration of most sensitive bacteria (0.5 micrograms/ml) consistently for 90 min. Based on this study, enrofloxacin would have to be administered parenterally to scimitar-horned oryx at 1.6 mg/kg every 6-8 hr (minimally) to maintain appropriate serum concentrations against susceptible bacteria. The metabolic energy scaled dosed regiment from this study appeared to be too low for the oryx.

Animals↗
PubMed1997

Disposition of single-dose intravenously administered enrofloxacin in emus (Dromaius novaehollandiae).

The pharmacokinetics of enrofloxacin in emus (Dromaius novaehollandiae) were examined following parenteral administration. A mean allometrically scaled dose of 2.2 +/- 0.03 mg/kg was administered as a single i.v. bolus, and serum samples were collected at predetermined intervals over a 24-hr period. Enrofloxacin levels were measured using high-performance liquid chromatography, and the resulting concentration versus time curve was analyzed using nonlinear regression with least squares parameter estimation. The data were best represented by a two-compartment model with a mean elimination half-life of 3.33 hr. Mean model independent parameters obtained were area under the curve (8.26 micrograms.hr/ml), mean residence time (4.40 hr), apparent volume of distribution (1.49 L/kg), and total body drug clearance (0.36 L/hr/kg). Mean serum concentrations exceeded the target peak of 2.0 micrograms/ml and remained above an estimated inhibitory concentration of 0.5 micrograms/ml for approximately 2 hr. Based upon the results of this study, enrofloxacin administered parenterally to emus at 2.2 mg/kg every 12 hr is expected to achieve therapeutic serum concentrations against susceptible organisms.

Animals↗
PubMed1997

Disposition of single-dose intravenously administered amikacin in emus (Dromaius novaehollandiae).

The pharmacokinetics of amikacin in emus (Dromaius novaehollandiae) was examined following parenteral administration. A mean 7.2 +/- 0.12 mg/kg dose was administered as a single i.v. bolus, and serum samples were collected at predetermined intervals over a 24-hr period. Amikacin levels were measured using a fluorescence polarization immunoassay, and the resulting concentration-versus-time curve was analyzed using nonlinear regression with least squares parameter estimation. The data were best represented by a three-compartment model with a mean elimination half-life (t1/2 beta) of 0.87 hr, with a longer rate of elimination from the third compartment (t1/2 gamma = 6.06 hr). Mean model-independent parameters obtained were area under the curve (269.66 micrograms.hr/ml), mean residence time (6.48 hr), apparent volume of distribution (0.18 L/kg), and total body drug clearance (0.03 L/hr/kg). Mean serum concentrations exceeded a target peak of 32.0 micrograms/ml and remained above an estimated inhibitory concentration of 8.0 micrograms/ml for approximately 12 hr. Mean serum levels had declined below a target trough of 4 micrograms/ml at 24 hr.

Amikacin↗
PubMed1997

Amikacin pharmacokinetics and the effects of ambient temperature on the dosage regimen in ball pythons (Python regius).

The serum concentration of amikacin following intracardiac and i.m. administration of amikacin (3.48 mg/kg) in 12 ball pythons (Python regius) housed at 25 degrees C and 37 degrees C was studied. Blood samples were collected by cardiocentesis at intervals up to 144 hr after administration of amikacin. Drug concentration-versus-time curves following intracardiac administration at both temperatures best fit a two-compartment open model. For snakes housed at 37 degrees C, the extrapolated time 0 concentration (mean +/- SD) was 17.64 +/- 3.5 micrograms/ml with a median elimination half-life of 4.5 days. The maximum concentrations were 11.98 +/- 1.67 micrograms/ml and 13.87 +/- 2.61 micrograms/ml for snakes housed at 25 degrees C and 37 degrees C respectively. There were no significant pharmacokinetic differences among the snakes housed at 25 degrees C and 37 degrees C. Model-independent parameters were area under the curve, 69,900 +/- 0.011 micrograms.min/ml, apparent volume of distribution at steady state, 410 +/- 106 ml/kg, clearance, 0.036 +/- 0.009 ml/min/kg, and mean residence time, 3,530 +/- 273.7 minutes. Mean serum amikacin concentrations did not reach the recommended therapeutic peak concentrations for mammals (25 micrograms/ml). In addition, the amikacin serum concentration did not fall below the recommended therapeutic trough concentrations (2 micrograms/ml) by 6 days. The serum amikacin concentrations were efficacious based on the area under the curve. Therefore, amikacin (3.48 mg/kg) administered i.m. to ball pythons should produce maximum serum concentrations against most pathogenic bacteria. In this study, it would have taken another half-life, or 4.5 days, before trough concentrations of 2 micrograms/ml were achieved. To prevent accumulation, a one-time administration of amikacin may be appropriate.

Amikacin↗
PubMed1997

Duodenal perforation in a cheetah (Acinonyx jubilatus).

An 11-yr-old female cheetah (Acinonyx jubilatus) from a privately owned breeding center for endangered species was referred for evaluation with a history of vomiting and depression of 10 days' duration. After anesthetic induction with tiletamine and zolazepam and anesthetic maintenance with isoflurane, a complete diagnostic workup was performed, including hematology, serum chemistry, and radiography. The clinical diagnosis was septic suppurative inflammation and hemorrhage in the abdomen, consistent with perforation or rupture of the gastrointestinal tract. An exploratory laparotomy showed a perforated duodenal ulcer, which was resected. Subsequent endoscopy revealed no further evidence of ulceration in the upper gastrointestinal tract. Biopsy of the ulcerated tissue collected from the duodenum revealed Gastrospirillum-like organisms. Histologic examination revealed widespread infiltration of lymphocytes and plasma cells into the lamina propria and submucosa. Intraepithelial leukocytes were present along with attenuation, erosion, and ulceration of the superficial epithelium. Fourteen days after surgery, this cheetah was returned to its breeding compound, and no subsequent vomiting has been observed for 4 yr.

Acinonyx↗
PubMed1996

The natural history of outpatient alcohol and drug abuse treatment in a private healthcare setting.

Managed healthcare has had a major impact on the delivery of alcohol and drug abuse treatment services in the private setting, primarily by shifting patient enrollment from inpatient to outpatient treatment programs. The purpose of this study was to investigate the natural history of outpatient alcohol and drug abuse treatment in a private, nonprofit healthcare setting. Patient profiles at pretreatment, their attendance record in a 6-week outpatient program, and their outcome in the year after treatment were evaluated in 120 patients with a DSM-III-R diagnosis of alcohol and/or cocaine dependence. There were 70 outpatients who successfully completed the program, and 50 who did not. Two subtypes of outpatient treatment failures were identified: S5 who prematurely left treatment against medical advice (n = 23), and S8 who attended treatment but continued heavy use of substances (Treatment Resistant, n = 27). A logistic regression revealed that younger age, multiple prior treatments, and employment problems were related to outpatient treatment failure. Outpatient failures did not immediately seek alternative treatment, and most of them continued heavy substance use in the year post-treatment: i.e., 82% vs. 43% successful completers (chi 2 = 13.8, df = 1, p < 0.01). Thus, there were a clinically relevant number of outpatient failures (42%), either because of lack of program attendance or continued substance use throughout treatment. These behaviors were related to continued heavy use of substances in the year after treatment.

Adult↗
PubMed1994

Use of a full-thickness autograft on the tarsus of an ostrich.

Full-thickness, cutaneous autografting was successfully performed on an adult female ostrich to heal a granulomatous wound on the right tarsus. With surgical techniques used in domestic species such as dogs and horses, skin grafting is an alternative in avian species when conventional wound closure is not appropriate.

Animals↗
PubMed1993

Surgical treatment of egg retention in emus.

We developed a surgical technique for management of retained eggs in emus. Clinical signs associated with egg retention include cessation of laying activity or failure to lay eggs, lethargy, anorexia, straining, and passing egg material, and diagnosis can be made by external palpation, abdominal radiography, and ultrasonography. The retained eggs were removed through a paramedian abdominal incision in all birds. One bird was euthanatized at surgery because of severe peritonitis resulting from uterine rupture at the site of obstruction by the retained egg. Three birds survived and were discharged from the hospital to the owners. Egg peritonitis resulting from eggs or egg remnants in the abdominal cavity was evident in the birds that survived surgery. Surgery and administration of antimicrobials were successful in resolving the peritonitis.

Animals↗
PubMed1993

Gentamicin toxicosis in a North American cougar.

This report documents nephrotoxicosis in a North American cougar (Felis concolor) caused by gentamicin overdose and describes a method of calculating drug dosages by metabolic scaling for species in which pharmacokinetic studies have not been performed. Determining drug dosages by metabolic scaling can decrease the likelihood of administering inappropriate drug doses in exotic animals.

Alopecia↗
PubMed1993

Inpatient vs outpatient treatment for substance dependence revisited.

Miller and Hester's 1986 review of inpatient versus outpatient alcohol treatment studies concluded with no "justification" for inpatient treatment. Further examination of these studies revealed shortcomings such as the use of random assignment designs which excluded psychiatrically-complicated patients. Carrier Foundation's inpatient/outpatient study of private psychiatric patients with alcohol and/or cocaine dependence includes a patient-treatment matching design to address weaknesses in the existing literature. Patients with high psychiatric severity and/or a poor social support system are predicted to have a better outcome in inpatient treatment, while patients with low psychiatric severity and/or a good social support system may do well as outpatients without incurring the higher costs of inpatient treatment. Preliminary results from 183 inpatients and 120 outpatients indicated outpatients, regardless of level of psychiatric severity, were 4 times more likely to be early treatment failures (chi-square = 41.2, df = 1, p < .01). While the determination of long-term follow-up status of early treatment failures is currently underway, this finding underscores the potential risk of early treatment failure in outpatient compared to inpatient substance abuse treatment programs and the importance of addressing the issue of early attrition in conducting outcome analyses.

Ambulatory Care↗
PubMed1992

[How tolerant are partial dose values? Some additional remarks on the concept of a tolerance dose].

By means of the NSD formula and its modifications (CRE, TDF) evaluated from radiotherapy experience by Ellis, it is possible to estimate the acceptance of applied radiotherapy and fractionation scheme. Because the parameters of the Ellis formula are calculated from patients data, they show a dispersion as usually in biological systems. These dispersions are considered as entrance error. In mathematical transformations errors are multiplied according to the principle of superposition of errors. Especially when judging tolerance values of organs of risk the dispersion is quite important. The problem of dispersion of resulting partial tolerance values is demonstrated by some examples of clinical cases.

Algorithms↗