PubMed Health⌕ Search

Biomedical subjects

J D Jensen

Publications and source records attributed to J D Jensen.

At least 19 recordsLinked to original sources
PubMed1999

Adenocarcinoma of the lung: electron microscopy of fine-needle aspiration biopsy specimens--a review of 73 cases.

During a 10-yr period, 128 consecutive cases of pulmonary adenocarcinoma of varying differentiation were diagnosed with percutaneous fine-needle aspiration biopsy. Sediments from the needle and syringe washings with 3% glutaraldehyde were obtained and processed for electron microscopic evaluation in 73 cases. Our results showed three types of adenocarcinoma: 62 cases of nonciliated bronchiolar cell origin, 6 cases of bronchioloalveolar cell origin, and 3 cases of mucous cell origin. In addition, there was an example of combined adenosquamous carcinoma and an instance of amphicrine carcinoma. Our study provided a more precise definition of the cytologic diagnosis and insight into the heterogeneity of lung adenocarcinoma. However, prognostic differences between cell types of lung adenocarcinoma were not observed.

Adenocarcinoma↗
PubMed1999

Cytopathologic evaluation of lung carcinomas presenting as brain metastasis.

Brain metastasis is an uncommon initial presentation of lung carcinoma. One arm of this analysis is a retrospective review of 137 cases of surgically diagnosed solitary brain metastasis, which were eventually found to be of lung origin, encountered at Hines VA Hospital during the period 1958 to 1996. The second arm is composed of fine-needle aspiration biopsy specimens of primary lung tumor in 23 patients with an initial clinical diagnosis of brain metastasis and without the benefit of surgery, seen from 1981 through 1996. Our results in both analyses indicate that pulmonary adenocarcinoma is the predominant primary tumor that initially manifests as a brain metastasis, approaching 76% (107 and 17 cases, respectively), followed by small-cell carcinoma at 20% (24 and five cases, respectively) and large-cell undifferentiated carcinoma and squamous-cell carcinoma at 2% each. The predominance of adenocarcinoma as a source of brain metastasis in lung cancer patients probably reflects its rising incidence overall of late. Collateral findings also suggest that surgical resection of a solitary and small brain metastasis as well as of a discrete lung primary, whenever feasible, as the most effective procedure to improve survival and quality of life of patients.

Adenocarcinoma↗
PubMed1998

[The auto- and endocrine function of the adipose tissue. Significance for metabolic complications in obesity].

The present review discusses recent research showing adipose tissue to be highly metabolically active, producing and releasing many different bioactive compounds besides free fatty acids (FFA) such as tumor necrosis factor alpha (TNF alpha), leptin, acetylation stimulating protein (ASP), plasminogen activator inhibitor-1 (PAI-1), cholesterol ester transfer protein (CETP), prostaglandins and oestrogens. Most of these compounds have autocrine effects on the adipose cells and they are presumably involved in the physiological regulation of blood flow, growth and metabolism of the adipose tissue. When the adipose tissue becomes enlarged, as seen in association with obesity, it has now been shown that several of the compounds produced in the adipose tissue (TNF, PAI-1, CETP etc.) may be directly involved in the pathogenesis of some of the complications commonly seen in association with obesity such as insulin resistance, hypertension, enhanced thrombogenesis, and premature atherosclerosis.

Adipose Tissue↗
PubMed1998

Metastasis of unknown origin: the role of fine-needle aspiration cytology.

Metastasis of unknown origin (MUO) manifests either as a tumor deposit in an organ, often cervical lymphadenopathy, or as a multiorgan carcinomatosis. As a diagnostic and therapeutic challenge, the definition of its cell type and possibly its origin is imperative, although a limited diagnostic investigation is usually recommended. At Hines VA Hospital from 1986 to 1994, there were 116 cases with admitting clinical diagnosis of MUO, evaluated by fine-needle aspiration cytology (FNAC). The ages of patients ranged from 29 to 82 years (mean 56 years). All were male; Caucasians predominated. The FNAC examination with Diff-Quik and Papanicolaou smears were complemented with special and immunostains in 48 cases (41%) and electron microscopy in 93 cases (80%). The FNAC involved lymph nodes in 57 cases (49%), liver in 27 cases (23%), skin in 22 cases (19%), bone in six cases (5%), lung in three cases (3%), and pleura in one case (1%). The neoplasm was generally cell typed, and there were 60 adenocarcinomas/poorly differentiated carcinomas, 26 small-cell carcinomas (SCC), 23 squamous-cell carcinomas (SQCC), and six undifferentiated large-cell carcinomas. The primary source was defined in 30 cases (26%), consisting of lung in 11 cases, prostate in nine, kidney in four, colon in four, pleura in one, and peritoneum in one. Clinical correlation also supported a lung origin for the SCC, while the majority of the SQCC in upper and middle cervical lymph nodes were considered head-and-neck tumors. Our results affirm that FNAC is a viable and simple procedure in MUO investigations.

Adult↗
PubMed1997

Pleural effusion cytology of embryonal rhabdomyosarcoma.

This case report concerns an embryonal rhabdomyosarcoma of the testis in a 31-yr-old white male patient who underwent radical left orchiectomy, followed by combined irradiation and chemotherapy, and who 2 yr later presented with dyspnea at rest, nonproductive cough, and lower back pain for 1 wk. Chest radiographs demonstrated a bilateral pleural effusion and diffuse infiltrating lesion of the pleurae, mimicking a mesothelioma. The pleural fluid displayed noncohesive, malignant, small, round cells about 2-5 times larger than mature lymphocytes. They had large, darkly stained, pleomorphic nuclei and bubbly cytoplasm with poorly defined borders. The diagnosis of embryonal rhabdomyosarcoma was supported by a positive myosin immunostaining and ultrastructural findings of intracytoplasmic actin and myosin-type microfilaments. Our case is also notable in that the tumor was a pure rhabdomyosarcoma involving a testicular origin, and the patient is the oldest reported in the literature.

Adult↗
PubMed1996

Comparison of dose requirement, serum erythropoietin and blood pressure following intravenous and subcutaneous erythropoietin treatment of dialysis patients. IV and SC erythropoietin.

OBJECTIVE: The purpose of the study was to investigate the effect of route of administration of erythropoietin (EPO) on the dose requirement in dialysis patients after intravenous (IV) and subcutaneous (SC) therapy. METHODS: The study was performed as a single centre, prospective, open, combined parallel and cross-over study of 50 dialysis patients, consecutively randomised to IV or SC treatment with EPO. The initial dose was 49 U.kg-1 3-times weekly, adjusted to increase haemoglobin (Hgb) from a median 5.3 mmol.1(-1) to a target of haemoglobin 6.5-7.5 mmol.1(-1). After reaching the target level, the haemoglobin was maintained for 4 months (Period 1). Then IV and SC treatment was switched for a further 4 months (Period 2). The study included high risk patients. The adjustment period was completed by 38 patients, Period one by 32 patients (IV/SC = 15/17; male/female = 19/13; age = 54 (24- 71) y), and Period two by 22 patients. RESULTS: No significant difference was found between the two groups in the reticulocyte response, the rate of Hgb increase (IV 0.7 versus SC 0.5, mmol.1(-1). month-1), time to reach target level (IV 43 versus SC 60 days), or total EPO dose per increase in haemoglobin to target level (IV 663 versus SC 946 (U.kg-1) per (mmol Hgb.1(-1)). The overall median maintenance dose during the last month of the two four month periods was 105 (range IV 51-336) U.kg-1.w-1 and SC 104 (range 21-321) U.kg-1.w-1. Through serum EPO levels were significantly higher during SC treatment. The blood pressure did not change significantly from the base level after either route of administration; start 133/80 versus 143/80 mmHg, target 127/78 versus 154/85 mmHg, and maintenance period 140/84 versus 142/85 mmHg. Thus, three-times weekly IV or SC EPO did not differ significantly in efficacy or in the effect on blood pressure in dialysis patients.

Adult↗
PubMed1996

Pharmacokinetic interaction between cyclosporine and the dihydropyridine calcium antagonist felodipine.

OBJECTIVE: In a double blind, randomised, placebo-controlled, cross-over study 12 healthy male volunteers were allocated to receive felodipine + placebo, cyclosporine + placebo, and felodipine + cyclosporine in order to investigate the interaction between the calcium channel blocker felodipine and cyclosporine as it affects the pharmacokinetics of felodipine, dehydrofelodipine, and cyclosporine, and 24-hour blood pressure measurements. METHODS: Single doses of cyclosporine (capsules, 5 mg/kg body weight) and of felodipine (extended release (ER) tablets 10 mg) were given at a 1-2 week interval. Plasma drug concentrations were followed for 2 days after drug intake. RESULTS: For cyclosporine, Cmax was increased after combined treatment (16%) compared to cyclosporine alone, but felodipine did not influence other kinetic parameters of cyclosporine. For felodipine, combined treatment with cyclosporine and felodipine increased AUC and Cmax (58% and 151%, respectively) and lowered mean residence time (24%) significantly compared to felodipine alone. For the metabolite dehydrofelodipine, too, AUC and Cmax were increased after the combined treatment (43% and 94%, respectively). Mean 24-hour systolic and diastolic blood pressures were significantly lower after felodipine, both when felodipine was given alone (121/68 mmHg) and in combination with cyclosporine (122/68 mmHg) compared to cyclosporine alone (127/73 mmHg). CONCLUSION: A combined single dose of cyclosporine and felodipine in healthy subjects increased the AUC and Cmax of felodipine suggesting a cyclosporine-induced decrease in the first-pass metabolism of felodipine, whereas the AUC of cyclosporine was only slightly increased by felodipine.

Adult↗
PubMed1995

Porphyria in childhood.

Porphyria in childhood is an uncommon problem but the recognition of these disorders is vitally important for affected children. Of the cutaneous porphyrias, erythropoietic protoporphyria, congenital erythropoietic porphyria, hepatoerythropoietic porphyria, and the hereditary form of porphyria cutanea tarda (PCT) can present in infancy or childhood. This article focuses on the porphyrias that present in infants and children along with a brief discussion of pathogenesis, cutaneous histopathology, and genetics of these metabolic disorders.

Adult↗
PubMed1995

The metabolism of erythropoietin in liver cirrhosis patients compared with healthy volunteers.

The purpose of the investigation was to study the metabolism of erythropoietin (EPO) in patients with liver disease. Twelve patients with liver cirrhosis and 10 healthy volunteers were studied. The patients were moderately anemic with a hematocrit of 33 vs 42% (medians) in the volunteers. The pharmacokinetic parameters were calculated after an intravenous (i.v.) injection of 100 U/kg of recombinant human EPO. The serum EPO was measured by radioimmunoassay at regular intervals until 48 h. The median terminal elimination half life in the cirrhosis patients was 5.15 h vs 5.37 h in the control subjects. The clearance was 7.78 vs 7.52 ml/min/1.73 m2 (ns). The steady-state volume of distribution was 3.69 vs 3.09 1/1.73 m2 (ns). The estimated endogenous EPO production was significantly higher in liver cirrhosis (486 vs 290 U/d/1.73m2, p < 0.01). The basal serum EPO was significantly higher in the cirrhosis patients (43.5 vs 26.3 U/l, p < 0.01). The hematocrit correlated inversely with the basal serum EPO level in the cirrhosis patients (r = -0.63, p < 0.04). The EPO-clearance was not related to the presence of ascites, esophageal varices, or to abnormal blood chemistry. It was concluded that normal metabolism of EPO was maintained in liver cirrhosis and that the cirrhotic patients had a moderate compensatory increase of EPO production in response to anemia.

Adult↗
PubMed1995

Effects of high dose atrial natriuretic peptide on renal haemodynamics, sodium handling and hormones in cirrhotic patients with and without ascites.

To elucidate and to try to reverse the antinatriuretic mechanisms in liver cirrhosis, atrial natriuretic peptide (ANP) was given as a pharmacological bolus dose (2 micrograms per kg body weight) to 14 cirrhotic patients, and as a control to 14 healthy subjects. The nine patients with ascites had baseline values of glomerular filtration rate (GFR), effective renal plasma flow (ERPF) and blood pressure (BP) similar to controls. Their distal tubular fractional reabsorption of sodium (DFRNa), estimated by the lithium clearance technique, was higher than in controls, and so were plasma values of aldosterone (564 vs. 119 pmol l-1 medians), endothelin (1.23 vs. 0.63 pmol l-1), ANP (7.5 vs. 3.6 pmol l-1) and cyclic GMP (8.8 vs. 4.6 nmol l-1); p < 0.01 for all. The five patients without ascites had higher GFR and ERPF, and lower plasma angiotensin II than controls. After ANP injection, similar plasma levels of ANP and cyclic GMP were reached in all groups. Urinary sodium excretion rate increased in controls (0.23 to 0.52 mmol min-1, p < 0.01), while GFR increased (108 to 117 ml min-1, p < 0.05), and DFRNa decreased (93 to 89%, p < 0.01). In cirrhotics with ascites sodium excretion was unaltered (0.12 to 0.11 mmol min-1), and so was GFR (84 to 83 ml min-1). Proximal tubular fractional reabsorption of sodium increased after 90 min, whereas DFRNa decreased immediately (97 to 96%, p < 0.01) though less markedly than in controls. Sodium excretion increased in four of five patients without ascites (0.23 to 0.27 mmol min-1, medians). In patients with ascites, endothelin in plasma decreased after ANP (p < 0.05). Plasma levels of angiotensin II, aldosterone and vasopressin were unchanged in all groups. In conclusion, although hyper-reabsorption of sodium occurred in the distal rather than the proximal part of the nephron in cirrhotic patients with ascites, ANP had no natriuretic effect. This was most probably due primarily to the lack of increase of GFR and blunted inhibition of DFRNa, attributed to high aldosterone. The effect of ANP in suppressing the high endothelin did not seem to improve sodium excretion.

Adult↗
PubMed1995

Effect of isradipine on renal haemodynamics and systemic blood pressure changes induced by intravenous infusion of endothelin in healthy humans.

BACKGROUND: In some vascular beds calcium-channel-blocking agents have been shown to possess some antagonism to endothelin-1 (ET-1)-induced vasoconstriction. This issue has not been well investigated in humans, however. METHODS: The study had a double-blind cross-over design. In 12 healthy human volunteers we investigated the effect of pretreatment with either isradipine 10 mg daily for 1 week or placebo on changes in (i) systemic and renal haemodynamics and (ii) renal handling of sodium and water induced by intravenous infusion of ET-1 at a rate of 1 pmol/min/kg for 60 min. RESULTS: Infusion of ET-1 affected systemic haemodynamics. The increase in diastolic blood pressure was similar after pretreatment with placebo (+6.8%) or isradipine (+5.3%). The changes in renal haemodynamics in response to ET-1 infusion were also familiar, e.g. renal plasma flow (-32.1% versus -31.2%), glomerular filtration rate (-8.8% versus -10.9%) and renal vascular resistance (+55.1% versus +52.7%). Likewise the changes in renal handling of sodium and water in response to ET-1 infusion were unaffected by pretreatment with placebo or isradipine, e.g. sodium excretion (-44.6% versus -40.8%), urine flow rate (-49.8% versus -38.9%) and clearance of lithium (-32.0% versus -29.1%). CONCLUSIONS: Intravenous infusion of ET-1 in healthy humans discretely increases diastolic blood pressure and profoundly decreases renal haemodynamics and excretion of sodium and water. Pretreatment with the calcium-channel blocking agent isradipine for 1 week in a clinically relevant dose does not interfere with the action of ET-1.

Adult↗
PubMed1994

The pharmacokinetics of recombinant human erythropoietin after subcutaneous injection at different sites.

The pharmacokinetics of recombinant human erythropoietin (RhEPO) were investigated after subcutaneous (s.c.) injection in the thigh and in the abdominal wall. Eleven healthy subjects, age 24.4 years (median), were studied. Each subject received two s.c. injections of 100 U.kg-1 RhEPO dissolved in 1 ml water: one injection in the thigh and another in the abdomen. Serum erythropoietin was measured regularly by radioimmunoassay until 144 h after each injection. The mean residence time was significantly longer after injection in the thigh than in the abdomen (32.7 vs 26.2 h). The estimated half-life of absorption was significantly longer after injection in the thigh than after abdominal application (14.9 vs 12.3 h). The estimated half-life of elimination was not significantly different (4.4 vs 4.8 h). The relative difference in the area under the curve between injection in the abdomen and the thigh in the same subject ranged from -36% to +68% but there was no significant difference in bioavailability. The peak concentration was not significantly different and appeared at around 10 h (Cmax thigh, 175 U.l-1 vs Cmax abdomen, 216 U.l-1). A twin-peak configuration of the concentration vs time curve with a significant second peak at 24 h was found after injection in the thigh but not after abdominal injection. In conclusion, the mean residence time was longer after administration in the thigh, probably due to delayed absorption, but bioavailability was not significantly different. Following injection in the thigh the concentration curve had two peaks. The differences may be due to regional variations in lymph flow and to physical activity.(ABSTRACT TRUNCATED AT 250 WORDS)

Abdomen↗
PubMed1994

Increased serum erythropoietin level during azathioprine treatment in renal transplant recipients.

One hundred and six renal transplant patients were studied. During the first 12 months after renal transplantation all patients were treated with cyclosporine (Cy) and prednisone. At 12 months after transplantation the patients were randomly allocated to either conventional treatment with azathioprine (Az) and prednisone (group Az) or to continued treatment with Cy and prednisone (group Cy). Serum erythropoietin (s-EPO), glomerular filtration rate (GFR) and hematocrit (Hct) were measured at 12, 18 and 24 months after transplantation. s-EPO rose in the group Az from 19 U/l (mean) at 12 months to 28 U/l (p < 0.01) at 18 months and remained elevated at 24 months at 29 U/l compared with baseline level and with healthy subjects without anemia 18 U/l (p < 0.01). There was no significant change in s-EPO in group Cy during the study. The Hct in the two groups was not significantly different. GFR was the same in the two groups at 12 months and after 24 months. In conclusion, a switch from Cy to Az 1 year after renal transplantation results in a sustained rise in s-EPO which may in part represent a compensatory phenomenon to bone marrow suppression.

Adolescent↗
PubMed1994

Reduced production, absorption, and elimination of erythropoietin in uremia compared with healthy volunteers.

The purpose of this study was to investigate the metabolism of erythropoietin (EPO) in uremia compared with healthy subjects. Twenty-one patients (nine men and 12 women) with end-stage renal failure and anemia and 12 healthy volunteers (3 women and nine men) were studied. The pharmacokinetic parameters were calculated after an i.v. and a femoral sc injection of 100 U/kg of recombinant human EPO. The serum EPO (s-EPO) was measured by radio-immunoassay at regular intervals until 48 h (i.v.) and 120 h (sc). In uremia, the median terminal elimination half-life was significantly longer (8.31 versus 4.92 h; P < 0.001) and the clearance was reduced (5.00 versus 7.88 mL/min per 1.73 m2; P < 0.01). The volume of distribution was (3.70 versus 3.31 L/1.73 m2) not significant. The estimated endogenous EPO production was significantly lower in uremia (146 versus 290 U/day per 1.73 m2; P < 0.001). After sc administration, the bioavailability was significantly lower in the patients (23.7 versus 38.5%; P < 0.01), and the maximal s-EPO was lower (113 versus 153 U/L; P < 0.05) and delayed (15.4 versus 11.0 h; P < 0.02), but the mean input time (sc) was not significantly different (23.3 versus 27.8 h). The basal s-EPO was lower in the uremic patients (20.0 versus 26.3 U/L; P < 0.05). There was no difference between patients treated with hemodialysis and peritoneal dialysis or between uremic men and women. There was no correlation between the pharmacokinetic parameters and age.(ABSTRACT TRUNCATED AT 250 WORDS)

Absorption↗
PubMed1993

Elevated level of erythropoietin in congestive heart failure relationship to renal perfusion and plasma renin.

BACKGROUND: In animal experiments reduction of renal perfusion can stimulate erythropoietin production. The relationship between renal haemodynamics and erythropoietin production is unknown in congestive heart failure. OBJECTIVE: The aim was to study the relationship between serum erythropoietin and renal haemodynamics, plasma renin activity and haematocrit in patients with congestive heart failure and in healthy control subjects. PATIENTS AND METHODS: Serum erythropoietin, renal plasma flow, glomerular filtration rate and plasma renin activity were determined in 14 patients with acyanotic congestive heart failure, and 36 healthy controls. RESULTS: Serum erythropoietin was significantly elevated in congestive heart failure 26.6 U l-1 (median) compared with controls 17.0 U l-1 despite a normal haematocrit, and increased with the severity of congestive heart failure (New York Heart Association class II: 17 U l-1 [n = 4]; class III: 30 U l-1 [n = 5]; class IV: 45 U l-1 [n = 5]). Significant inverse correlations between serum erythropoietin and renal plasma flow (r = -0.60, P < 0.03), and between serum erythropoietin and glomerular filtration rate, were found in congestive heart failure but not in the control subjects. A significant positive correlation (r = 0.71, P < 0.03) was demonstrated between serum erythropoietin and plasma renin activity in congestive heart failure. CONCLUSION: A severe reduction in renal perfusion in congestive heart failure appears to cause an increase in serum erythropoietin.

Adult↗
PubMed1993

Effect of captopril on the renal veno-arterial gradient of erythropoietin and oxygen in unilateral renal artery disease.

Twenty-nine patients with unilateral renal artery stenosis or occlusion were investigated. The veno-arterial gradient (VA-gradient) of erythropoietin (EPO), haemoglobin oxygen saturation and plasma renin activity (PRA) was determined separately in each kidney before and 1 h after angiotensin converting enzyme inhibition (ACE-inhibition). The VA-gradient of EPO and of hemoglobin oxygen saturation were the same in the affected and unaffected kidney during basal conditions. During ACE-inhibition the VA-gradient of EPO disappeared on the affected side but not on the unaffected side. A fall in s-EPO after ACE inhibition was demonstrated in the renal vein on the affected side (-1.4 U l-1, p < 0.01), in the contralateral vein (-0.8 U l-1, p < 0.01) and in the aorta (-0.6 U l-1, p < 0.01). The O2-gradients were reduced on both sides after captopril, from 10.8-7.5% (p < 0.04) on the affected side and from 10.8-9.0% (p < 0.04) on the contralateral. It is suggested that the stimulated renin-angiotensin system may be important for EPO production in the affected kidney in unilateral renal disease.

Adult↗
PubMed1992

Atrial natriuretic peptide and parathyroid hormone (1-84) in relation to noradrenaline induced changes in blood pressure in uraemic and healthy subjects.

In order to evaluate the hormonal regulation of blood pressure (BP) in uraemia 12 patients on chronic maintenance dialysis and 14 healthy controls were studied. BP and plasma concentrations of atrial natriuretic peptide (ANP), cyclic 3',5'-guanosine monophosphate (cGMP), and intact parathyroid hormone (PTH(1-84)) were determined before, during, and after a 60 min noradrenaline infusion 0.1 micrograms kg-1 body wt. min-1. Mean BP increased to the same extent in the uraemic patients (median 15 mmHg, range 6-25 mmHg) as in the controls (12 mmHg, 5-25 mmHg). ANP increased during noradrenaline infusion both in patients (7.2 to 8.3 pmol/l, medians, p < 0.01) and in controls (4.4 to 6.0 pmol/l, p < 0.01), and so did cGMP (patients: 31.6 to 35.9 nmol/l, p < 0.05; controls: 6.6 to 8.7 nmol/l, p < 0.01). PTH(1-84) was higher in the uraemic patients than in the controls, but was unchanged during noradrenaline infusion in both groups. Correlation analyses gave no evidence of a direct relation between BP and ANP, but basal PTH(1-84) was negatively correlated to basal mean BP in the patients (rho = -0.615, p < 0.05), but not in the controls. In conclusion, noradrenaline induced similar elevations of BP in dialysis patients as in healthy controls despite elevated ANP and PTH(1-84) in the patients, and ANP release was stimulated in both groups. PTH(1-84) may participate in blood pressure regulation in uraemic patients.

Adult↗