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Biomedical subjects

M Larsen

Publications and source records attributed to M Larsen.

At least 19 recordsLinked to original sources

[Physical causes of accidental falls among the elderly in their own homes].

Accidental falls in elderly persons involve considerable illness and great hospital costs. During the period 1971-1986, the incidence has risen from 14 to 19 per 1000 annually. Four hundred and seventy-three individuals aged 60 years or more who had fallen in their own homes and who sought help in Odense Hospital after the accident were interviewed consecutively. The replies to these interviews described the circumstances involved in the fall together with the health and social conditions. Women constituted 78% of the material with preponderance of people living alone as compared with the background population. Just under half of the patients had had a previous fall. Fractures were sustained in 40% of the cases. In 51% of the cases, a definite or probable external circumstance was the cause of the fall. In 150 out of 237 accidental falls, caused by external circumstances, the accident was considered to have been preventable by means of eg more accessible lighting, non-slip carpeting, removal of doorsteps, more suitable arrangement of furniture and better supportive measures beside stairs. The risk of falling is found to increase markedly in persons aged 75 years or more. Prophylactic measures are recommended before patients reach this age by means of information to elderly persons and to persons involved in home care about situations involving risks.

Accidental Falls

HIV infection at outcome of pregnancy in the Paris area, France.

The prevalence of HIV infection in women at end of pregnancy, irrespective of outcome, was determined in a comprehensive survey of both women and medical centres during successive 4-week periods in four areas of the Paris region, France. Blood samples were tested anonymously for antibodies to human immunodeficiency virus (HIV)-1 and HIV-2. Of the 11,593 blood samples 0.40% (95% confidence interval [CI] 0.28-0.51) were positive for HIV-1 and 0.02% (95% binomial interval [BI] 0.002-0.065) for HIV-2. Seroprevalence was higher among women with ectopic pregnancy (2%) (95% BI 0.24-7.04); the rate in women having an elective or therapeutic abortion was more than twice that in those delivering babies (0.70% vs 0.28%, p less than 0.05, relative risk 2.54, 95% CI 1.36-4.75). Studies with neonatal HIV seroprevalence as a surrogate for HIV prevalence in pregnant women would underestimate prevalence in these women.

Abortion, Therapeutic

Lens fluorescence in relation to nephropathy in insulin-dependent diabetes mellitus.

The relationship between diabetic nephropathy and blue-green lens fluorescence, lens transmittance, and other lens fluorometry parameters was studied in patients with long-term insulin-dependent diabetes mellitus. The findings in 10 patients who presented with diabetic nephropathy were compared with those of 11 patients of comparable age and duration of diabetes but without nephropathy. Diabetic nephropathy was associated with increased lens fluorescence (P = 0.04) and decreased lens transmittance (P = 0.045). We propose that lens changes may be responsible for various psychophysical abnormalities in diabetic patients and that our results explain the correlation of these abnormalities with the degree of microangiopathy.

Adult

In vivo passage through calves of nematophagous fungi selected for biocontrol of parasitic nematodes.

The experiment was designed to test the survival and performance of stress selected nematophagous fungi after passage through the gastro-intestinal tract of cattle. Ruminating calves were fed daily with a fixed amount of fungal material grown on barley grains. The excreted dung was collected on days four and five after the start of the feeding experiment. Barley grains were washed out of the excreted dung and incoculated on water-agar plates. After incubation for one week, nine of ten fungal isolates were re-isolated from these plates. The predatory capacity of the fungi in the excreted faeces was tested in a dung pat bioassay and a faecal culture system. In the dung pat bioassay, two fungi of the genus Arthrobotrys and six of the genus Duddingtonia reduced the development of Ostertagia ostertagi third stage larvae by 85% (61%-93%), compared to the number of larvae developed from fungus-free control pats. In seven out of these eight isolates, the reduction of larvae in the faecal cultures was 92% (76%-99%).

Animals

Development of immunity to Ostertagia ostertagi (Trichostrongylidae: Nematoda) in pastured young cattle.

This experiment comprised 3 groups of calves, (+P2), (-P2) and (-P1), which all started their first grazing season as parasite-free calves. The (+P2)- and (-P2)-group grazed 2 seasons. In the first season the (-P2)-group of calves was grazing a pasture with no detectable trichostrongyles and treated with anthelmintics every second week. The untreated (+P2)-group grazed an Ostertagia ostertagi contaminated pasture. During the second grazing season these 2 original groups grazed together with a new group of first-year grazing calves (-P1) on paddocks infected with O. ostertagi. Parasitological analyses showed that (+P2)-group had negligible egg excretions in the second year in comparison with (-P2) and (-P1). This indicated, that the egg output may be regulated through acquired immunity. The difference in egg excretions was not reflected in the serum pepsinogen levels, which were only slightly elevated for all groups in the second year. Post mortem examination at the end of the experiment showed that only the (-P1)-group harboured relatively high numbers of worms in the abomasa at that time. Antibodies of 3 immunoglobulin classes were investigated: IgA, IgG1 and IgG2. The IgA and IgG1 responses correlated with the presence of developing and adult worms in the abomasa and they remained elevated in the (+P2)-group throughout the experiment, perhaps indicating an involvement of these antibodies in a protective immune response. In the (-P2)-group the IgA and IgG1 showed fast and sharp rises during the second season that most likely were age-related and as such a result of maturation of the immune system. The role of IgG2 is unclear as the IgG2 response was weak in all groups of calves and difficult to relate to the parasitological data.

Aging

[Infrared tympanic thermography. A comparison of body temperature measured rectally and from the tympanic membrane].

Infrared tympanic thermography is a new method of measuring body temperature. We compared body temperature measured in the rectum and in the ear in 25 patients. The results reveal a difference of average +/- 0.3 degree C. We also measured the time used to perform the above procedures. We found that the preparation and completion procedures took on average two minutes and 50 seconds when the body temperature was measured in the rectum. Taking the temperature in the ear took on average 42 seconds. We found that this new method was an accurate and quick method to measure body temperature.

Body Temperature

[Prevention of perinatal hepatitis B virus transmission. Epidemiology and cost/efficacy ratio in the Paris region].

The HBs antigen (AgHBs) was detected in 152 out of 6605 (2.3 percent) pregnant women who attended four representative maternity clinics in the Paris region. In 98 percent of the cases this finding reflected chronic hepatitis B virus infection. Among women born outside France (47 percent of the women tested, 79 percent of the AgHBs positive women), the relative risk was 6 for Asiatics, 5.5 for Africans and 4 for French women born in overseas departments or territories. Whatever the women's geographical origin, studies of their medical history revealed no significant difference between AgHBs positivity and AgHBs negativity. Overcrowding and multiparity correlated globally with the presence of AgHBs, but this correlation was absent in French women born in France. In non-African and non-Asiatic women detection guided by medical and socio-familial criteria would not be efficacious. The authors recommend systematic detection of AgHBs in pregnant women and estimate at about 180,000 french francs the cost of prevention for each case evolving toward the vital complications of chronic hepatitis B virus infection, an outcome which in the long term may affect 600 individuals born each year and who had contracted the infection during the perinatal period.

Adult

Longterm remission of multiple brain metastases with tamoxifen.

A case of multiple brain metastases from breast carcinoma treated with tamoxifen is described. She remained in remission for 58 months and is still alive after 82+ months of hormone therapy. The case indicates that hormonal treatment may be very effective in the management of brain metastases from breast carcinoma.

Activities of Daily Living

Differential spectrofluorometry in the human vitreous: blood-retina barrier permeability to fluorescein and fluorescein glucuronide.

A method is described for the separate quantitation of fluorescein and fluorescein glucuronide in the vitreous by differential spectrofluorometry. An ocular fluorometer was equipped with monochromatic laser excitation at two rapidly interchangeable wavelengths. The data analysis accounts for absorption of light in the cornea, lens, and extrinsic ocular fluorophores. Examination of seven patients with insulin-dependent diabetes and different degrees of diabetic retinopathy demonstrated that both fluorescein and fluorescein glucuronide enter the eye through the blood-retina barrier. The mean ratio between the permeabilities of fluorescein glucuronide and fluorescein was 0.9 (range, 0.3-1.9). Thus, differences in the molecular size and lipid solubility of the two substances appear to be of little or no importance for their inward penetration of the barrier. No association was found between the relative permeability and the degree of retinopathy.

Adult

Determination of spatial coordinates in ocular fluorometry.

A method has been developed for the determination of spatial coordinates of ocular fluorescence measurements made by a non-contact-lens type of fluorometer (Fluorotron, Coherent Inc., Palo Alto, Calif., USA). The method is based upon a mathematical model of the instrument and the eye. The model is adapted to the individual eye by the extraction of information from the fluorescence scan and the use of keratometry to determine the radius of curvature of the anterior corneal surface. The validity of the model was examined by comparison of the ocular axial length as measured by fluorometry vs ultrasonometry in 26 eyes of healthy human subjects. The results of fluorometry differed from those of ultrasonometry by less than +/- 2%.

Adult

Lens fluorometry: light-attenuation effects and estimation of total lens transmittance.

Front-face fluorometry of the axial fluorescence profile of the lens is influenced by attenuation of light along the optical pathways leading to and from the detection volume. The resulting distortion is evident when the curve is compared with the intrinsic profile that can be recorded by direct measurement on the transected lens. Assuming that attenuation of light by scatter and absorption is proportional to fluorescence, the intrinsic profile can be reconstructed from the non-invasive fluorescence profile. The calculations involve the deduction of total lens transmittance and fluorescence-related absorptivity, parameters that provide essential information about the optical quality of the lens. The method was applied to human lens fluorometry in vivo and in vitro (excitation 430-490 nm, fluorescence 530-630 nm). Even the most anterior lens fluorescence measurements were found to be markedly affected by attenuation of light in the lens. Lens transmittance estimates agreed within +/- 12% with direct measurements of lens transmittance. The differences were due in part to inter-individual variations in the shape of the intrinsic fluorescence profile of the lens.

Absorption

Ability of the fungus Pleurotus pulmonarius to immobilise preparasitic nematode larvae.

In vitro experiments showed that the oyster mushroom Pleurotus pulmonarius exerts a strong immobilising effect on preinfective larvae of the animal parasitic nematodes Ostertagia ostertagi, Cooperia oncophora, Oesophagostomum quadrispinulatum and Cyathostoma species. Infective stages of the same species seemed less vulnerable to fungal attack, possibly because they are protected by their outer cuticle.

Animals

In vitro stress selection of nematophagous fungi for biocontrol of parasitic nematodes in ruminants.

Laboratory experiments were designed to select nematophagous fungi that were able to survive in vitro conditions simulating passage through the gastro-intestinal tract of cattle. All of the tests were conducted at 39 degrees C. In a primary stress selection step in diluted rumen fluid, 21 isolates were obtained. Each of the primary stress selected isolates was tested in synthetic saliva, rumen fluid simulating the activity in the rumen, rumen fluid followed by pepsin-hydrochloric acid treatment simulating the additional effect of ruminal and abomasal activity, pepsin-hydrochloric acid solution simulating conditions in the abomasum and finally in a trypsin solution as an example of enzyme activity in the gut. The effect of the rumen fluid alone, or rumen fluid followed by pepsin-hydrochloric acid treatment, were responsible for the reduction in surviving fungal isolates. Only six of thirteen isolates belonging to the genus Arthrobotrys survived while seven of eight isolates of the genus Duddingtonia survived. Fourteen isolates were tested for their predatory capacity in a dung pat bioassay. Fungi of the genera Arthrobotrys and Duddingtonia reduced the development of Ostertagia ostertagi third stage larvae by approximately 75% and 96% respectively compared to the number of larvae that developed from fungus-free control pats.

Animals

Long-term results of extracapsular cataract extraction with posterior chamber lens implantation: sodium hyaluronate 1% vs hydroxypropyl methylcellulose 2%.

We investigated the frequency of surgical complications and the long-term outcome in terms of visual acuity, intraocular pressure and post-operative complications in 206 extracapsular cataract extraction procedures with posterior chamber lens implantation using either sodium hyaluronate 1% (Healon) or hydroxypropyl-methylcellulose 2% over a follow-up period of 12 months. We found no significant difference in the results of using either of the two viscoelastic agents.

Adult

Blood-retina barrier permeability in diabetes during acute ACE-inhibition.

We assessed the acute effect of ACE-inhibition (captopril) on blood-retina barrier (BRB) permeability in 10 hypertensive insulin-dependent diabetic patients with background retinopathy in a double-masked placebo controlled cross-over study. All patients underwent ophthalmological examination, fundus photography, fluorescein angiography, vitreous fluorometry, and continuous blood pressure recording within 3 h of the drug/placebo administration. The decrease in mean arterial blood pressure, from placebo treatment 149/92 +/- 17/7 to captopril treatment 132/83 +/- 14/7 mmHg (mean +/- SD), P less than 0.01 was not accompanied by a significant decrease in BRB permeability, which was 2.51 (1.24-9.15) with placebo and 3.02 (1.25-13.93).10(-7) cm/s during captopril treatment (geometric mean and-range), NS. Our study suggests that abnormal leakage through the BRB in hypertensive insulin-dependent diabetic patients with background retinopathy is caused predominantly by structural changes in the retinal vessels whereas hydrostatic forces play a minor role.

Adult

[The perinatal transmission of the hepatitis B virus in the Paris area].

HBsAg was detected in 152 pregnant women among 6,605 (2.3%) screened in the prenatal clinics of four hospitals representative of the Paris metropolitan area. In 98% of cases, HBsAg positivity indicated chronic HBV carrier status. Among patients born out of continental France (47% of screened women, 79% of positive women) relative risk of chronic infection was 6 in Asians, 5.5 in Africans, and 4 in French women born in non-continental France. No significant difference in medical history was seen between HBsAg-positive and HBsAg-negative patients, in any of the birthplace groups. In women born out of continental France, number of children and crowding in the home were correlated with HBsAg-positivity; these correlations were not found in French women born in continental France. In non-African, non-Asian women, screening on the basis of medical, social and familial criteria (simulated in this study) would not be effective. Routine screening for HBsAg in pregnancy is advocated. The cost of the prevention of each case of perinatally acquired chronic HBV infection by routine screening followed by prophylactic treatment of a risk neonates was estimated at 180,000 French Francs (35,000 dollars). This approach is the only means of preventing the long-term life-threatening complications of chronic HBV infection in the 600 neonates born each year in France to HBsAg-positive mothers.

Africa

[Perinatal transmission of the hepatitis B virus in Paris region].

HBsAg was detected in 152 pregnant women among 6,605 (2.3%) screened in the prenatal clinics of four hospitals representative of the Paris metropolitan area. In 98% of cases, HBsAg positivity indicated chronic HBV carrier status. Among patients born out of continental France (47% of screened women, 79% of positive women) relative risk of chronic infection was 6 in Asians, 5.5 in Africans, and 4 in French women born in non-continental France. No significant difference in medical history was seen between HBsAg-positive and HBsAg-negative patients, in any of the birthplace groups. In women born out of continental France, number of children and crowding of the home were correlated with HBsAg-positivity; these correlations were not found in French women born in continental France. In non-African, non-Asian women, screening on the basis of medical, social and familial criteria (simulated in this study) would not be effective. Routine screening for HBsAg in pregnancy is advocated. The cost of the prevention of each case of perinatally acquired chronic HBV infection by routine screening followed by prophylactic treatment of at risk neonates was estimated at 180,000 French Francs (35,000 dollars). This approach is the only means of preventing the long-term life-threatening complications of chronic HBV infection in the 600 neonates born each year in France to HBsAg-positive mothers.

Female