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Biomedical subjects

L Sperling

Publications and source records attributed to L Sperling.

At least 55 records · Page 3Linked to original sources
PubMed1983

Functional studies in 79-year-olds. II. Upper extremity function.

As part of the Gerontological and Geriatric Population Study of 79-year-old people in Göteborg, a representative subsample comprising 112 women and 93 men took part in a study of upper extremity function. Thirty-eight per cent of the women and 37% of the men had disorders in the upper extremities. The investigation included tests of co-ordination, static strength in the key-grip and the transversal volar grip, power capacity in opening jars and a bottle, basal movements in the upper extremities in personal hygiene and dressing activities, function in the kitchen e.g. reaching shelves, manual tasks including tests of pronation and supination of the forearm. In the key-grip as well as in the transversal volar grip men showed a generally larger decrease in strength with age than women compared to 70-year-olds in a previous population study. Significant correlations were found between strength in the key-grip and the performance time in the test of co-ordination. Women produced about 66% of the muscular force of the men when opening jars. Significant correlations were found between strength in the transversal volar grip and the maximal torque for opening the jars. Female and male subjects who were not capable of handling the electric plug in the manual ability test had significantly weaker strength in the key-grip. The importance of designing products and adapting the environment so as to correspond to the functional capacity of the elderly, is emphasized.

Activities of Daily Living↗
PubMed1982

Fossil mammals and artefacts from the Middle Awash Valley, Ethiopia.

A review of fossil mammalian faunas from the Middle Awash indicates they span most of the later Neogene and document evolutionary change in several mammalian groups, especially Primates, Proboscidea and Artiodactyla. Oldowan artefacts first appear in the late Pliocene, while Acheulian and later industries and apparent occupation sites occur in Pleistocene beds.

Animals↗
PubMed1982

Undermethylation at the 5' end of the albumin gene is necessary but not sufficient for albumin production by rat hepatoma cells in culture.

We have measured methylation of the albumin gene in clones of rat hepatoma cells that vary quantitatively in their rates of synthesis of albumin and in variant and hybrid cells that produce no albumin. Although the albumin gene is undermethylated for its entire length in rat liver, only the 5' end is ever undermethylated in hepatoma cells. Moreover, undermethylation of the 5' end of the gene appears to be necessary for stable expression of the albumin gene in hepatoma cells. Since undermethylation of this region is found in some variant cells that fail to produce albumin, it is not a sufficient condition for albumin gene expression. Despite the excellent correlation between undermethylation of the 5' end of the albumin gene and its stable expression, the results argue against the possibility that the methylated state of such genes during development determines whether they will or will not be expressed.

Albumins↗
PubMed1980

Chromatin repeat length in somatic hybrids.

In order to study the mechanisms by which a characteristic repeat length is inherited in somatic cells, it was necessary to develop a method for determining repeat length with a precision of 1 to 2 base pairs. Hybrid clones between parental cell lines differing in repeat length by 6 base pairs were isolated. The four independent hybrid clones characterized had repeat lengths intermediate between those of the parental lines; however, it could be demonstrated that these repeat lengths are unique values and do not arise from a double distribution of the parental repeat lengths. It therefore is concluded that repeat length in somatic cells is determined by a common pool of diffusible substances.

Animals↗
PubMed1980

Chromatin repeat length correlates with phenotypic expression in hepatoma cells, their dedifferentiated variants, and somatic hybrids.

Chromatin repeat length is known to differ among the tissues of organisms. We have examined the repeat length of somatic cells in culture and have found an unexpected correlation between this parameter and the state of differentiation of the cells. Three sequentially derived subclones of a rat hepatoma, similar in phenotype, present a constant repeat length of 189 (+/- 1) base pairs. Three independent variant clones do not express hepatic functions and each has a different repeat length: 184 base pairs, 188 base pairs, and 192 base pairs. Somatic hybrids between the two types of cells in which liver functions are extinguished have a repeat length close or identical to that of the nonexpressing parent. In the case of one hybrid clone that reexpresses the liver phenotype and has undergone some chromosome loss, the 189-base-pair repeat length characteristic of the well-differentiated cells is reestablished. Finally, an amelanotic variant clone derived from a pigmented hamster melanoma clone also shows a signficantly altered repeat length. No correlations have been observed between repeat length and either generation time or chromosome number. Maintenance of the expression of differentiation therefore appears to be associated with a constant repeat length, and loss of the former with a modification in repeat length, suggesting that chromatin packaging is intimately involved in the regulation of gene expression.

Animals↗
PubMed1980

Evaluation of upper extremity function in 70-year-old men and women.

As a part of the Gerontological and Geriatric Population Study of 70-year-old people in Gothenburg 75 men and 101 women were subjected to tests of upper extremity function. Twenty men and 22 women were healthy without any locomotor disorders. The investigation included tests of muscular co-ordination, static strength in key-grip, transversal volar grip, elbow flexion and submaximal endurance in handgrip. Results in healthy subjects were compared with results in a reference group of young subjects aged 20-30 years. Seventy-year-old healthy subjects did not differ significantly from young subjects regarding strength in key-grip and endurance in transversal volar grip. The largest decrease in function was seen in healthy 70-year-old subjects in the test of muscular co-ordination and in strength in the transversal volar grip. In general healthy 70-year-old women showed a slighter decrease in function than men. Significant correlations were found between strength in key-grip and transversal volar grip and between strength in elbow extension and flexion of 70-year-old subjects. A slight correlation was found between strength in elbow extension and static knee extension at 90 degrees knee angle in 70-year-old healthy subjects.

Activities of Daily Living↗
PubMed1980

Evaluation of functional capacity in activities of daily living in 70-year-old men and women.

Various activities of daily living of importance for an independent and active life were studied in 70-year-old systematically selected men (n = 190) and women (n = 229) recruited from a population study. The tests concluded basal movements in the upper extremities in hygiene and dressing activities, ability to rise from a stool, function in the kitchen e.g. reaching shelves and tasks including pronation and supination of the forearm and measurements of comfortable walking speed. In a selected subsample, tests of ability to climb various step-heights and a manual ability test were also performed. As regards basal movements in the upper extremities in hygiene and dressing activities, the hand-to-toe test caused most problems. A minority of both sexes had difficulty rising from a stool and in performing the pronation-supination tests. Problems in the test of reach were mainly correlated to the height of the subject, presence of arthritic disorders, and positional vertigo. The mean walking speed was in both sexes lower than that recommended in Sweden as the norm for pedestrians at signalized intersections. All but one subject could climb up and down a 40 cm step using a handrail. Without using handrail one-fifth of the women but only a few men had problems at this step-height but all managed the 30 cm step. Both sexes showed a decline in manual dexterity compared to 20-30-year-old subjects. Correlations were found between muscle strength, step test results and walking speed as well as between walking speed and leisure-time physical activity. There was also a correlation between problems in handling the plug in the manual ability test and strength in the key-grip.

Activities of Daily Living↗
PubMed1977

Pterin-6-aldehyde, a cancer cell catabolite: identification and application in diagnosis and treatment of human cancer.

Active folic acid degradation with the formation pterin-6-aldehyde is a previously undescribed characteristic of cancer cells in tissue culture. Neither normal adult epithelial and fibroblastic cells nor human amniotic cells nor mouse embryonic fibroblasts degrade folic acid to a measurable degree. Twenty-nine patients whose diagnoses were not revealed until after the test of their first morning urine for pterin-6-aldehyde was completed were studied for the presence or absence of pterin-6-aldehyde by thin-layer chromatography. Pterin-6-aldehyde was found in the urine at about 300 nmol/ml or greater only in those 13 patients with a tissue diagnosis of cancer. When the cancer was totally resected, the pterin-6-aldehyde was no longer found in the urine postoperatively. Pterin-6-aldehyde is not found in the urine of healthy patients at this level of detection unless their diets are supplemented with folic acid.

Adolescent↗
PubMed1977

The grip pattern of the healthy hand during eating.

Thirty subjects with healthy hands have been studied in standardized meal experiments comprising serving, eating and drinking. The activities were filmed and the grips classified by means of a descriptive code system and analysed by automatic data processing. The investigation has resulted in new information about the grip pattern of the normal hand as well as detailed data on fingers and parts of fingers used. The study demonstrates the value of analysing hand function with reference to integrated activities.

Activities of Daily Living↗
PubMed1977

Grip function of the healthy hand in a standardized hand function test. A study of the Rancho Los Amigos test.

In an experimental study 30 healthy subjects performed the tests of prehensile function in the Rancho Los Amigos test. The subjects were allowed a free choice of grip instead of those prescribed when the test is used for clinical purposes. The hand-grips were filmed and registered by means of a descriptive code system and the results were subjected to automatic data processing. The results showed that healthy subjects performing the RLA test used a stereo-typed grip pattern as a consequence of the uniform purpose of the hand-grips. Comparison with the results from a standardized meal study in the same subjects showed that functional assessment of a patient with a test of this type is not directly applicable to integrated daily activities, as several of the hand-grips most frequent in daily activities were rarely used. Comparison with types of grip prescribed for clinical use of the test showed that normal subjects often did not spontaneously handle the objects in the manner intended by the test.

Activities of Daily Living↗
PubMed1975

Squid retinochrome.

Retinochrome is a photosensitive pigment located primarily in the inner portions of the visual cells of cephalopods. Its absorption spectrum resembles that of rhodopsin, but its chromophore is all-trans retinal, which light isomerizes to 11-cis, the reverse of the situation in rhodopsin. The 11-cis photoproduct of retinochrome slowly reverts to retinochrome in the dark. The chromophoric site of retinochrome is more reactive than that of most visual pigments: (a) Hydroxylamine converts retinochrome in the dark to all-trans retinal oxime + retinochrome opsin. (by Sodium borohydride reduces it to N-retinyl opsin. (c) Lambda max of retinochrome shifts from 500 to 515 nm as the pH is raised from 6 to 10, with a loss of absorption above pH 8; meanwhile above this PH a second band appears at shorter wavelengths with lambda max 375 nm. These changes are reversible. (d) If retinochrome is incubated with all-trans 3-dehydroretinal (retinal2) in the dark, some 3-dehydroretinochrome (retinochrome2, lambda max about 515 nm) is formed. Conversely, when retinochrome2, made by adding all-trans retinal2 to bleached retinochrome or retinochrome opsin, is incubated in the dark with all-trans retinal some of it is converted to retinochrome. Retinal and 3-dehydroretinal therefore can replace each other as chromophores in the dark.

Borohydrides↗