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Biomedical subjects

N Christensen

Publications and source records attributed to N Christensen.

At least 37 records · Page 2Linked to original sources
PubMed1993

Snoring, sympathetic activity and cardiovascular risk factors in a 70 year old population.

In order to describe the relation between snoring, cardiovascular risk factors, metabolic factors and sympathetitic activity, 804 70-year-old males and females were classified according to snoring habits and life-style factors (alcohol and tobacco consumption), blood pressure, body mass index (BMI), plasma lipids (triglycerides, cholesterol, high density lipoprotein), plasma catecholamines (epinephrine, norepinephrine), fasting blood glucose and glucose tolerance test (1 gram glucose per kg body weight given and blood glucose was measured 1 and 2 hours thereafter) were evaluated in all participants. Self-reported snoring was associated with gender (males showed higher prevalence than females, p < 0.05), alcohol consumption (p < 0.01), BMI (p < 0.001), systolic (p < 0.01) and diastolic (p < 0.05) blood pressure, glucose tolerance test (p < 0.01), plasma norepinephrine (p < 0.05) and partly with tobacco consumption (p = 0.08). No associations were found between snoring and fasting glucose, plasma lipids, plasma epinephrine or in the use of antihypertensive medication. In multivariate analysis, with forced entry of gender, BMI, physical activity, alcohol and tobacco consumption, the relation between snoring and blood pressure ceased; only systolic blood pressure was associated with snoring (p < 0.05). Snoring was still associated with plasma norepinephrine (p < 0.001) and abnormal glucose tolerance (p < 0.001). We conclude that, in a 70-year-old population, snoring is associated with gender, BMI and alcohol consumption. Snores showed higher plasma norepinephrine and abnormal glucose tolerance.

Aged↗
PubMed1992

Suicides among Danish patients with cancer: 1971 to 1986.

The risk of suicide or other violent death was assessed among 296,331 patients with cancer in Denmark from 1971 to 1986 by linkage between the National Cancer Registry and mortality files. There were 1,637 violent deaths, of which 568 were suicides. The relative risk (RR) of suicide was significantly increased in the first 2 years after a cancer diagnosis, independent of age at cancer diagnosis. A lower suicide risk was seen after diagnosis of localized cancer (RR = 1.3; 95% confidence intervals [CI]: 1.1 to 1.4), compared with that seen after a nonlocalized cancer (RR = 1.9; 95% CI: 1.5 to 2.4). High risks for suicide were observed for patients of each sex after diagnoses of tumors of the brain and nervous system and with cancer of the lung, stomach, rectum, and kidney; high risks were found among male patients only after a diagnosis of lymphoma or pancreatic cancer. Surprisingly, the risk of suicide has increased significantly in more recent years.

Accidental Falls↗
PubMed1992

Malignant Warthin's tumour: a case study.

Malignant transformation of a benign Warthin's tumour (adenolymphoma) is extremely rare. The light microscopic and ultrastructural features of an adenocarcinoma arising in a Warthin's tumour in the parotid gland are described. Light microscopy demonstrated a transition zone from the benign to the malignant component, and the malignant cells revealed oncocytic features by both light- and electronmicroscopy.

Adenolymphoma↗
PubMed1992

Vegetable oils instead of xylene in tissue processing.

In an effort to improve working conditions in the histopathologic laboratory, we have investigated whether less toxic substances may be substituted for the toxic organic solvent xylene currently in use. Xylene is used in the clearing as well as the deparaffinization process. We have tested whether the substitution of xylene by olive oil and coconut oil leads to any difference in the quality of the histologic sections. Two tissue blocks from each of 232 specimens sent for histopathologic evaluation were subjected to parallel processing in xylene and oil. The specimens represented a broad spectrum of tissue types. All sections were stained with hematoxylin-eosin to permit evaluation of histologic and cytologic details. Furthermore, a range of histochemical and immunohistochemical stainings were applied to a subgroup of tissue sections. The results showed qualitative differences between xylene-processed and oil-processed tissue in only a minority of cases. In no cases were the oil-processed samples considered less suitable for histologic diagnosis. In the histochemical and immunohistochemical stainings, no differences were registered. Although the long-term stability of oil-processed tissue remains to be clarified, we conclude that less toxic vegetable oil may probably be substituted for xylene without losing valuable diagnostic information.

Histological Techniques↗
PubMed1988

Hydrophobic 3.7 kDa surfactant polypeptide: structural characterization of the human and bovine forms.

The human and bovine forms of the hydrophobic 3.7 kDa surfactant polypeptide have been structurally analyzed. The polypeptide is essentially inert to enzymatic proteolysis, and methods for analysis include peptide handling in organic solvents and fragment generation by limited acid hydrolysis. The molecule exhibits N-terminal trimming, and the relative abundance of the different starting positions varies both among species and between adult and fetal forms of the surfactant polypeptide. The bovine major form is one residue shorter than the mature 35-residue human molecule. Comparison of the porcine, human and bovine polypeptides reveals a conserved hydrophobic middle/C-terminal segment and a variable hydrophilic N-terminal part.

Amino Acid Sequence↗
PubMed1987

Changing clinical spectrum of splenic abscess. A multicenter study and review of the literature.

The changing demographics of splenic abscess in regard to predisposition, clinical setting, diagnosis, bacteriologic findings, and treatment have been presented based on 19 patients from five institutions and 170 patients reported in the literature since 1978. These data, in turn, have been compared with a previously published retrospective review of the world literature from 1900 to 1977. It has become clear that since 1978, splenic abscess is diagnosed earlier in its presentation due to the widespread use of improved imaging techniques, immunocompromised patients comprise a much larger proportion of patients (24 percent) than previously due to increasing use of steroids and chemotherapeutic agents, and the diagnosis of fungal splenic abscess, almost unheard of before 1978, has increased to 26 percent of patients. The diagnostic sensitivity of computerized tomography (96 percent) has clearly been shown to be superior to ultrasonography, and gallium, indium, and technetium-99m liver and spleen scanning. The diagnosis of splenic abscess, however, is still often not considered due to its rarity and the presence of predisposing conditions which obscure its clinical presentation. Untreated splenic abscess is still fatal, and although splenectomy is the mainstay of treatment, it appears that antifungal treatment without splenectomy can be recommended for patients with disseminated fungal disease as long as bacterial abscess has been ruled out by invasive culture techniques. Scattered reports of percutaneous drainage exist and are increasing in the literature, although the results are as yet inconclusive. Eventual recovery depends on early diagnosis and successful treatment of the underlying condition.

Abscess↗
PubMed1987

Lipofuscinosis of the human uterus.

A case of uterine lipofuscinosis in a patient with Friedreich's ataxia is described. Ultrastructural investigation confirmed the mitochondrial origin of the lipofuscin. Clinically, the patient suffered from brown bowel syndrome. Both the brown bowel syndrome and the uterine lipofuscinosis in the present case may be related to Friedreich's ataxia.

Adult↗
PubMed1986

Pathogenicity and persistence of pleural effusion disease virus isolates in rabbits.

Nine isolates of pleural effusion disease agent or virus (PEDV) from treponema-infected rabbits in various countries were examined for pathogenicity and persistence in rabbits. The isolates showed a wide range of pathogenicity and were categorized into three groups according to the severity of the acute infection. Group 1 comprised isolates causing more than 50% mortality, group 2 isolates causing mortality below 50%, while group 3 comprised isolates causing almost subclinical infections. The range between group 1 and group 3 was similar to that observed with virulent and avirulent progeny of the original PEDV isolate. Infection by each of the nine isolates resulted in a chronic low level viraemia which persisted for up to 2 years or more. Viral progeny of pathogenic isolates obtained in serum after the 2nd month of infection failed to induce clinical disease on rabbit inoculation. The chronic, subclinical infection was associated with a moderate, continued increase in serum IgG, but circulating immune complexes could not be demonstrated. Two years after infection slight histopathological changes were present in lymph nodes, spleen, liver, heart and lung. Evidence of immune complex disease could not be demonstrated.

Animals↗
PubMed1985

A double-blind, crossover study of a sustained-release tablet of ketoprofen and normal ketoprofen capsules in the treatment of patients with osteoarthritis.

A double-blind, crossover study was carried out to assess the efficacy and tolerance of a sustained-release tablet formulation of ketoprofen given as a single daily 200 mg dose compared with 2 X 50 mg normal formulation capsules of ketoprofen twice daily. Eighty-four patients with osteoarthritis of the hip and/or knee were admitted and received treatment for periods of 3 weeks, preceded by a 1-week placebo wash-out period, with each of the two formulations, in random order. Patients were seen after each study period and clinical objective and subjective assessments made of signs and symptoms of the disease, consumption of rescue analgesic and unwanted effects. Forty-eight of the patients continued, mainly on the sustained-release formulation, in an open long-term tolerance study lasting 3 months. The results were analyzed for 68 patients who completed the double-blind phase and for 33 who completed the open phase of the study. The patients who were withdrawn did so mainly for non-drug related reasons; 19 patients did so because of gastric disorders during the first phase. The incidence of side-effects was low and similar in frequency and nature with both formulations; those that were reported were mild and principally gastro-intestinal. Both active treatment periods afforded similar symptomatic relief and were preferred to placebo by all but 2 patients. No significant differences were found between active treatments, although there was a trend in favour of the sustained-release formulation for most of the parameters studied as there was in patient preference.

Aged↗
PubMed1984

Survival of human fetal pancreatic explants in organ culture as reflected in insulin secretion and oxygen consumption.

Human fetal pancreatic explants were maintained in organ culture for up to 12 days in medium TC 199 or RPMI 1640 supplemented with 20% fetal calf serum. The explants were cultured at their air-liquid interface on a Millipore filter supported by surgical gel foam (ALI technique). The insulin accumulation in the culture medium decreased considerably when explants were maintained for 6 days in RPMI 1640. No corresponding decline was observed with medium TC 199. Four out of 9 RPMI 1640-cultured and 8 out of 11 TC 199-cultured explants responded with an increased insulin release when challenged with high glucose-plus-theophylline after one week of culture. With these explants there was a statistically significant correlation between their rates of respiration and insulin secretion. Furthermore, significant correlations were found between the fetal crown-heel length on the one hand--and the insulin content, insulin response, and oxygen uptake on the other--of the TC 199 cultured explants. There was no apparent change in the rate of insulin accumulation by addition of high glucose or amino acids to the TC 199 medium. It is concluded that oxygen uptake measurements, requiring only minute amounts of tissue, are useful for assessing the viability of human fetal pancreatic explants, and that the ALI technique for maintaining human fetal pancreas in culture offers no obvious advantage over that of the submersion technique. There is also evidence that suggests a better functional preservation in culture medium TC 199 than in RPMI 1640.

Fetus↗
PubMed1983

The analysis of an anti-fluorescein cytotoxic response.

The detailed kinetics of the appearance of clones of anti-fluorescein cytotoxic T lymphocytes (CTL) in a primary limiting dilution response have been examined. The addition of factors from the supernatants of concanavalin A-stimulated rat spleen cell cultures was necessary to obtain linear dose-response curves and strong primary responses. In a standard primary response the maximum detectable number of specific clones was found, on day 5, to be derived from precursors having a frequency of 1 in 10 000 spleen cells. When limiting dilution cultures were restimulated on day 3, responses on day 5 were unaffected but new clones appeared on day 7 with a frequency of 1 in 1000. The emergence of the day-7 response depends on the addition of factor(s) on day 3. It is proposed that the early low frequency precursors detected on day 5 and the high frequency precursors detected on days 7-9 are derived from two stages in the differentiation lineage of CTL precursors. Restimulation of limiting dilution cultures involves not only the continued clonal expansion of primary responses but also the emergence of new "clones" of specific CTL.

Animals↗
PubMed1983

Venous and nerve invasion as prognostic factors in postoperative survival of patients with resectable cancer of the rectum.

The histopathologic and clinical findings in 682 patients with carcinoma of the rectum have been analyzed. Invasion of veins and nerves by primary growth was found in 38.9 and 34.9 per cent, respectively. The five-year survival rate for patients with resectable tumors was 49 per cent. The age, Dukes' staging, and presence and/or absence of liver metastases, of venous invasion, and of nerve invasion were found to be of statistically significant importance for the prognosis. Sex was found to be on the borderline of significance and Broders' grading was even less significant. Invasion of veins was found statistically significant more frequently than nerve invasion, but the present investigation revealed the importance of the invasion of veins as well as of nerves. When venous invasion was observed, liver metastases developed over three times as frequently in these patients as when metastases were not demonstrated. In contrast to Dukes' staging. Broders' grading can be applied to tumor biopsies preoperatively. The importance of venous and nerve invasion for the selection of patients for adjuvant therapy after termination of surgical treatment is discussed.

Adolescent↗
PubMed1983

Ontogenesis of somatomedin and insulin receptors in the human fetus.

This study examines the ontogenesis of somatomedin and insulin receptors in man. Particulate plasma membranes were prepared by ultracentrifugation from various tissues removed from fetuses after abortion and classified as less than 17, 17-25, and greater than 25 cm in length. The binding of iodinated insulinlike growth factors 1 (IGF-1) and 2 (IGF-2), somatomedin A (SMA), multiplication-stimulating activity (MSA), and insulin was examined at the different ages. In the liver, cross-reaction studies revealed separate insulin and IGF-2 receptors. The Scatchard plots of insulin binding to liver membranes were curvilinear and showed an increase in the concentration of insulin receptors with advancing age. A single IGF-2 receptor was found on liver and no alteration was observed during development. The brain contained a lower concentration of insulin receptors. A change in the brain receptors for somatomedins occurred during development. Early in gestation, a high concentration of a low-affinity IGF-1 receptor was found. After approximately the 17th wk of gestation a higher affinity IGF-1 receptor appeared, which then increased in concentration. Cross-reaction studies also revealed changes in the specificity of these receptors during development. In the youngest fetal group IGF-2 was preferentially bound. Around midgestation a separate IGF-1 receptor, indicated by the preferential displacement of iodinated IGF-1 by IGF-1, appeared. In contrast, iodinated IGF-2 bound to a receptor where IGF-1 and IGF-2 were equipotent.

Brain↗
PubMed1981

Pantothenic acid nutritional status in the elderly--institutionalized and noninstitutionalized.

Pantothenic acid nutritional status was evaluated in 37 men (32 noninstitutionalized and five institutionalized) and 54 women (33 noninstitutionalized and 21 institutionalized) 65 yr of age or older. A fasting blood sample, a 24-h urine specimen and a food consumption record for 1 wk were obtained from each subject. Hematological, anthropometric, and dietary parameters indicated these 91 subjects were similar to elderly populations evaluated in other studies. Pantothenic acid was analyzed by both radioimmunoassay and microbiological assay. By combining methods it was possible to differentiate various forms and derivatives of pantothenic acid. Free pantothenic acid, but not the phosphoderivatives, was observed in urine. Microbiological and radioimmunoassay estimations of pantothenic acid showed good correlation (r = 0.91). Pantothenic acid excretion in the institutionalized subjects (7.5 +/- 1.3 (x +/- SEM) mg/g creatinine) was comparable to the excretion levels in the noninstitutionalized subjects (5.9 +/- 0.6 mg/g creatinine). Those consuming pantothenic acid supplements had significantly higher excretion levels. Blood pantothenic acid values between the groups, noninstitutionalized (537 +/- 27.4 ng/ml) and institutionalized (615 +/- 47.3 ng/ml), were comparable. The average dietary intake of pantothenic acid for the elderly population studied was 5.9 +/- 0.1 mg/day with the institutionalized and noninstitutionalized subjects having a similar intake of 2.9 mg/1000 kcal. Institutionalized elderly males and females were consuming 2237 and 1962 kcal, respectively, while their noninstitutionalized counterparts were consuming 2201 and 1887 kcal.

Aged↗