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Biomedical subjects

T Marshall

Publications and source records attributed to T Marshall.

At least 217 records · Page 12Linked to original sources
PubMed1985

The diagnosis of flat foot in the child.

The term flat foot is surrounded by confusion and there is little to help the clinician to identify cases which require treatment and to avoid treating many children unnecessarily. Research for 25 years has been aimed at elucidating this problem by identifying and evaluating a series of signs and tests. These tests allow the recognition of the abnormal foot as early as possible, when efficient treatment is likely to be most effective. The results indicate that evaluation of the flat foot should be based on a combination of signs, with most emphasis on the result of the great toe extension test.

Child↗
PubMed1985

Plasma apolipoprotein pattern in fish-eye disease examined by high-resolution two-dimensional electrophoresis.

We compared the plasma protein patterns of the two living patients suffering from fish-eye disease with those of appropriate controls, using high-resolution two-dimensional electrophoresis. Quantitative abnormalities were detected in plasma polypeptides corresponding to the isoforms of apolipoproteins A-I and A-II. The disease was characterized by normal concentrations of proapo A-I but dramatically subnormal concentrations of the other apo A-I isoforms and apo A-II. No significant difference was detected in the concentrations of other plasma proteins. These findings are discussed in relation to other apolipoprotein disorders.

Apolipoprotein A-I↗
PubMed1984

Underwater life support based on immobilized oxygen carriers.

One of the primary problems that hinders humans in their efforts to explore and develop the ocean realms is the lack of a ready supply of oxygen. Practical methods have not yet been devised for using the vast amount of oxygen dissolved in ocean waters for human life support in an undersea environment. Fish and other water-breathing animals have solved this problem by utilizing hemoglobin as a molecular oxygen pump. To achieve a similar oxygen extraction capability, we have explored various methods of oxygen extraction that are based on immobilized forms of hemoglobin. Improved methods for immobilizing hemoglobin or other oxygen carrying molecules and a method for extracting the available dissolved oxygen from natural waters and other fluids are described. The techniques that have been developed allow for immobilization of oxygen carriers at high concentration in a state where they are capable of reversible oxygen binding, and also allow for regeneration of the carrier in the event of oxidation of the oxygen-binding site.

Animals↗
PubMed1984

Artifacts associated with 2-mercaptoethanol upon high resolution two-dimensional electrophoresis.

The presence of 2-mercaptoethanol in the protein denaturing solution used to prepare samples for high resolution two-dimensional electrophoresis can result in artifacts when the two-dimensional patterns are detected by silver staining. These are (i) spots of discrete isoelectric point and electrophoretic mobility, (ii) horizontal bands of the same electrophoretic mobility as the spots (corresponding predominantly to molecular weights of 54,000 and 68,000), and (iii) vertical streaks of variable length and intensity. Although the nature and source of artifacts have not been positively identified the evidence suggests that they are probably not inherent in the 2-mercaptoethanol itself but rather released by the latter from some component common to both the first- and second-dimension constituents of the electrophoretic system.

Electrophoresis, Polyacrylamide Gel↗
PubMed1984

Detection of protein in polyacrylamide gels using an improved silver stain.

A much improved silver staining procedure for the detection of protein in polyacrylamide gels of 0.8-3.0 mm thickness is described. It achieves very high sensitivity (detecting less than 0.01 ng bovine serum albumin/mm2) by overstaining and subsequently removing nonspecific background stain using a modified, reliable destaining procedure. Maximum sensitivity follows prediamine equilibration in 0.1% (w/v) formaldehyde solution. With two-dimensional electrophoresis the improved staining procedure reveals greater than 200 polypeptides in unconcentrated human urine and greater than 150 polypeptides in a single human fingerprint.

Electrophoresis, Polyacrylamide Gel↗
PubMed1984

Leukaemia and childhood cancer in twins.

Data from the United Kingdom on childhood leukaemia and childhood cancer in twins and from the United States on leukaemia in twins are analysed by a new method. The method distinguishes determinants occurring before the stage of pregnancy corresponding with the cleavage of MZ pairs, from determinants occurring after this point. It derives estimates of the frequencies of each class of determinant. Different aetiological models are characterised by particular combinations of frequencies, and can thus be identified. The results of the analysis suggest that the major determinants of childhood leukaemia, and possibly of the solid cancers as well, operate before the time of cleavage. They operate either on the early zygote or its component germ cells. These early determinants are not, however, sufficient causes and require combination with postcleavage determinants, which subsequently occur in about a quarter of all children, before leukaemia can ensue.

Child↗
PubMed1984

Polyoma virus transformation and two-dimensional electrophoresis patterns of baby hamster kidney cell native proteins.

The protein extracts of baby hamster kidney cells (BHK 21/C13) before and after malignant transformation by polyoma virus were resolved by isoelectric focusing in the first dimension and electrophoresis on concave 4-24% (w/v) polyacrylamide gradient gels in the second dimension. The resulting two-dimensional patterns were visualised by ultrasensitive silver staining. Major differences were observed in the protein distribution patterns of the two cell lines. Brief trypsinisation of the cells, prior to extraction of cell protein, had little effect upon the protein patterns of BHK cells. Similar treatment of the transformed cells markedly reduced the staining intensity of a string of spots which were present in far greater abundance than in the original BHK cells. The findings suggest that these proteins are located on the surface of the transformed cells and probably under the surface prior to transformation.

Animals↗
PubMed1984

Two-dimensional electrophoresis of proteins in human serum: improved resolution by use of narrow pH gradients and prolonged electrophoresis.

The limited resolution of serum proteins achieved with a simplified technique of two-dimensional electrophoresis (Clin. Chim. Acta 103: 51-59, 1980) has been improved by using different ampholyte (Ampholine) mixtures in the first dimension, to obtain relatively shallow pH gradients, and prolonged electrophoresis time in the second dimension. The technique has been further simplified, without negative effect, by decreasing the concentration of non-ionic detergent (first dimension), omitting both sodium dodecyl sulfate equilibration and the use of a stacking gel (second dimension), and by using an improved silver-staining procedure. Reverse-polarity isoelectric focusing and non-equilibrium pH-gradient electrophoresis have been successfully used to resolve the basic polypeptides in serum after deleting sodium dodecyl sulfate from the sample preparation. These combined techniques reveal over 1100 polypeptides in human serum. After immunodeletion of albumin, additional serum polypeptides are seen. Immunodeletion of serum proteins from plasma reveals polypeptides that are relatively specific to plasma.

Ampholyte Mixtures↗
PubMed1984

Sodium dodecyl sulfate polyacrylamide gel electrophoresis of serum after protein denaturation in the presence or absence of 2-mercaptoethanol.

Human serum proteins were evaluated by sodium dodecyl sulfate polyacrylamide gel electrophoresis after protein denaturation in the presence or absence of 2-mercaptoethanol. Both electrophoretic techniques give characteristic and reproducible banding patterns and achieve a high degree of resolution within the limits of a one-dimensional separation. The major protein bands have been identified, and the merits of the two techniques are compared. Protein denaturation in the absence of 2-mercaptoethanol gives more discrete bands for the purpose of protein identification by maintaining the disulfide-bridge-dependent polypeptide associations characteristic of many serum proteins. However, simultaneous use of both electrophoretic techniques enhances identification by exploiting the response of an individual protein to mercaptoethanol treatment. The clinical potential of this approach for detecting protein disorders is discussed.

Animals↗
PubMed1984

Urgent cholecystectomy.

A retrospective review of cholecystectomy at the Naval Regional Medical Center, Portsmouth, Virginia revealed 92 patients (22%) who had urgent or early operation for acute cholecystitis. There were no infections or deaths in this group and the complication rate was similar to that of patients who had elective cholecystectomy. We advocate liberal use of intraoperative cholangiography in these patients. Interestingly, a high number of positive common duct explorations were found in those patients with a bilirubin level of over 4.0 mg/dl.

Abdomen, Acute↗
PubMed1983

Excreta disposal facilities and intestinal parasitism in urban Africa: preliminary studies in Botswana, Ghana and Zambia.

The relationships between intestinal parasitism and excreta disposal technologies in Gaborone (Botswana), Ndola (Zambia) and Kumasi (Ghana) were investigated. Parasitic prevalence and intensity rates amongst groups of urban residents having similar socio-economic status and housing, but different excreta disposal technologies, were compared. In Gaborone, there was no evidence of a difference in intestinal parasitism between those using aqua privies and having access to public taps and those in identical houses enjoying flush toilets, in-house water connections and showers. In Ndola, the group with sewered aqua privies had larger houses, cleaner toilets, better water supplies, longer residence and more people in paid employment than the groups using pit latrines or communal flush toilets. Despite this, the sewered aqua privy users were not found to be different from the other groups with regard to hookworm and protozoal infection but had significantly higher Ascaris infection rates. In Kumasi, despite the differences in toilet type--from squalid communal aqua privies, through often fouled bucket latrines to well-maintained flush toilet systems--and despite also the differences in water provision, no evidence was obtained of any differences in intestinal parasitism between the groups studied. These findings suggest that the provision of superior water and sanitation facilities to a small cluster of houses, or to houses scattered through an area, may not protect those families from infection if the over-all level of faecal contamination of the environment is high. The sample sizes and response rates achieved in this study were low and follow-up studies, employing the same methodology but with larger samples, are recommended.

Adolescent↗
PubMed1983

Variations in the prevalence and intensity of microfilarial infections by age, sex, place and time in the area of the Onchocerciasis Control Programme.

Epidemiological data gathered by the Onchocerciasis Control Programme from 66 villages in West Africa have been analysed. All of these villages were surveyed twice and 10 a third time. The first surveys were conducted around the time when control activities started and provide baseline data against which to assess the effectiveness of control. The second and third surveys were conducted two to five years later. 18,778 persons were registered in the first surveys and 15,783 (84.1%) were examined for microfilariae. The prevalence of microfilarial infection was higher among males, increased rapidly with age in both sexes until about 25 years and levelled off at about 90% in males and 85% in females. The age-sex adjusted prevalence rates in different villages varied from 5% to 93% but were above 60% in three quarters of the villages. After two to five years of control there was an over-all fall in the prevalence of infection of about 4 to 5% a year. Among children born since control started, only seven of 1871 examined were found to be infected with microfilariae compared to an expected number of 79, had there been no change in prevalence rates.

Adolescent↗
PubMed1983

Relationships between mortality, visual acuity and microfilarial load in the area of the Onchocerciasis Control Programme.

The relationships between onchocercal infection, visual acuity and mortality have been examined using epidemiological data gathered by the Onchocerciasis Control Programme from 66 villages in West Africa. All of these villages were surveyed at least twice. 18,778 persons were registered at the first surveys which were conducted around the time when control activities started. The second surveys were conducted two to five years later. 14,961 persons (79.7%) were alive and registered again, 786 (4.2%) had died, 2776 (14.8%) had moved and 255 (1.4%) could not be traced. The prevalence of blindness and of visual damage other than blindness both increased markedly with age, and the degree of visual damage was strongly associated with level of microfilarial infection. Among adults, the prevalence of blindness was higher for males than for females at all ages. The prevalence and intensity of microfilarial infection were also higher among males but this was not sufficient to explain their excess blindness. Logistic regression analysis showed that males were 1.5 times more likely to be blind than females of the same age and same level of microfilarial infection. The presence of visual damage at the first survey considerably increased the risk of mortality between the first and second surveys for both males and females. Mortality rates were three to four times higher among the blind and about 1.5 times higher among those with visual damage other than blindness compared with those with no visual damage. There was some evidence, for males but not for females, that mortality was also directly related to microfilarial load.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1983

Treatment of cryptorchidism with pulsatile luteinizing hormone-releasing hormone (LH-RH).

This preliminary report describes a new method of treating bilateral cryptorchidism that may modify the need for surgical intervention. Four of five boys (3 1/2, 3 1/2, 7, 11 and 12 1/2 years of age) given hourly subcutaneous pulses of luteinizing hormone-releasing hormone (LH-RH, 10 to 100 micrograms/day, given in a 3-min pulse every hour) showed evidence of testicular descent after 3 to 19 weeks. The battery-operated, programmable syringe driver was well tolerated by the boys, and the daily insertion of the scalp-vein needles was managed at home by their parents.

Child↗
PubMed1983

Behavioral and physiological effects of ethanol in high-risk and control children: a pilot study.

Blood and breath acetaldehyde levels were measured following ethanol ingestion (0.5 ml/kg) in 11 boys familially at risk for alcoholism and 11 age-matched controls. No significant differences were found between groups for acetaldehyde, objective, or subjective measures of intoxication. Previous reports of acetaldehyde as a marker of risk for alcoholism were not confirmed. Baseline behavioral state predicted response to alcohol. Children tended to have a subjective response in a direction opposite from the baseline mood state.

Acetaldehyde↗