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Biomedical subjects

P Mullis

Publications and source records attributed to P Mullis.

13 recordsLinked to original sources

The response of trained athletes to six weeks of endurance training in hypoxia or normoxia.

This study was performed to investigate the effect of training under simulated hypoxic conditions. Hypoxia training was integrated into the normal training schedule of 12 endurance trained cyclists. Athletes were randomly assigned to two groups and performed three additional training bouts per week for six weeks on a bicycle ergometer. One group (HG) trained at the anaerobic threshold under hypoxic conditions (corresponding to an altitude of 3200 m) while the control group (NG) trained at the same relative intensity at 560 m. Preceding and following the six training weeks, performance tests were performed under normoxic and hypoxic conditions. Normoxic and hypoxic .VO2max, maximal power output as well as hypoxic work-capacity were not improved after the training period. Testing under hypoxic conditions revealed a significant increase in oxygen saturation (SpO 2, from 67.1 +/- 2.3 % to 70.0 +/- 1.7 %) and in maximal blood lactate concentration (from 7.0 to 9.1 mM) in HG only. Ferritin levels were decreased from 67.4 +/- 16.3 to 42.2 +/- 9.5 microg/l (p < 0.05) in the HG and from 54.3 +/- 6.9 to 31.4+/- 8.0 microg/l (p = 0.17) in the NG. Reticulocytes were significantly increased in both groups by a factor of two. In conclusion, the integration of six weeks of high intensity endurance training did not lead to improved performance in endurance trained athletes whether this training was carried out in hypoxic or normoxic conditions.

Adult↗

Circadian elevation of IL-6 levels in Muckle-Wells syndrome: a disorder of the neuro-immune axis?

Muckle-Wells syndrome (MWS) is a rare autosomal dominant hereditary disorder characterized by chronic recurrent urticaria, arthralgia, sensorineural deafness, and in some cases nephropathy due to amyloidosis (AA type). We report a 21-year-old woman and her father, both suffering from this syndrome, in whom elevated serum levels of IL-6 could be documented during the flares of urticaria, and discuss the relevance of this finding for MWS.

Acute Disease↗

[Convulsive seizure].

A formerly healthy 14-year old boy with difficulties at school was admitted after two generalized seizures. Blood samples taken in the emergency room revealed normal serum-values for glucose and magnesium, but low calcium and elevated phosphorus. First evaluations showed normal age-related psychophysical development, serum-PTH was elevated and serum-1,25(OH)2D was normal. A CT-scan disclosed symmetric intracerebral calcifications. Further investigations confirmed the diagnosis of pseudohypoparathyroidism type 1B. Adequate treatment with calcium and calcitriol normalized serum-calcium, phosphorus and serum-PTH. Interestingly, school performance improved, as did personal activity.

Adolescent↗

Fetal haemoglobin levels in adult type 1 (insulin-dependent) diabetic patients.

Glycated haemoglobin levels (HbA1 and HbA1c) are established parameters of long-term glycaemic control in diabetic patients. Depending on the method used, fetal haemoglobin interferes with the assays for glycated haemoglobin. If present in high amounts, fetal haemoglobin may lead to overestimation of glycated haemoglobin levels, and therefore, of average blood glucose concentration in diabetic patients. Glycated (HbA1c) and fetal haemoglobin levels were measured by high pressure liquid chromatography in 60 (30 female) adult Type 1 (insulin-dependent) diabetic patients of Swiss descent, and were compared with levels obtained from 60 normal, non-diabetic control subjects matched for age and sex. Fetal haemoglobin levels were significantly higher in the diabetic patients (0.6 +/- 0.1%, mean +/- SEM; range: 0-3.6%) than in the control subjects (0.4 +/- 0.1%, p < 0.001). Elevated fetal haemoglobin levels (> or = 0.6%) were found in 23 of 60 diabetic patients (38%) compared to 9 of 60 control subjects (15%; chi 2 = 8.35, p < 0.01). In addition, fetal haemoglobin levels in diabetic patients are weakly correlated with glycated haemoglobin (HbA1c) (r = 0.38, p < 0.01). Fetal haemoglobin results were confirmed with the alkali denaturation procedure, and by immunocytochemistry using a polyclonal rabbit anti-fetal haemoglobin antibody. A significant proportion of adult patients with Type 1 diabetes has elevated fetal haemoglobin levels. In certain patients this may lead to a substantial over-estimation of glycated haemoglobin levels, and consequently of estimated, average blood glucose levels. The reason for this increased prevalence of elevated fetal haemoglobin remains unclear, but it may be associated with poor glycaemic control.

Adolescent↗

Isolated growth hormone deficiency: analysis of the growth hormone (GH)-releasing hormone gene and the GH gene cluster.

Isolated GH deficiency (IGHD) cannot be distinguished on the grounds of anti-human (h) GH antibodies and stunted growth response to exogenous hGH. DNA analysis was proposed to classify children with IGHD. Genomic DNA was extracted and studied by restriction endonuclease analysis after extraction from the circulating lymphocytes of 53 children with IGHD. These children included 5 pairs of siblings and 5 individuals from 10 families, whose parents (n = 20) and brothers and sisters (n = 5) were also analyzed. Twenty-five adults, including individuals from 3 families of normal height, were studied as controls. No deletion within the hGH gene cluster was identified using a [32P]hGH cDNA clone as a probe. A compound heterozygosity for a hGH-1 deletion or a mutation have not been found. The allelic frequencies for 5 common restriction fragment length polymorphisms were similar in patients and controls. The distribution and frequency of the distinct haplotypes in the hGH gene family revealed no differences between IGHD (n = 30 chromosomes) and controls (n = 48 chromosomes). No deletion or restriction fragment length polymorphisms could be found using a hGH-releasing hormone cDNA clone as a probe in patients or controls. This large volume of data gathered from a caucasian population indicates that the great majority of patients with IGHD has no structural abnormalities of the hGH gene cluster, particularly no hGH-1 gene deletion. In addition, they have no gross deletions within the hGH-releasing hormone gene.

Adolescent↗

RFLPs for Duchenne muscular dystrophy cDNA clones 9 and 10.

The complete 14-kb cDNA for the gene causing the X-linked recessive muscular dystrophy (MD) type Duchenne (DMD) and Becker (BMD) has recently been cloned and made available for deletion/duplication screening in patients. It detects 65 exon-containing nonpolymorphic HindIII fragments spread over a gene locus of about 2,000 kb. When the entire DMD cDNA is used, deletions/duplications can be found in about 65%-70% of affected patients, permitting direct carrier detection by densitometric scanning. But in cases where no deletion/duplication is detectable, RFLP analysis, specially favored within the gene, will be the method for carrier-status determination. Clones 9 and 10-1.2-kb and 0.7-kb fragments, respectively, of the 14-kb DMD cDNA--have been hybridized with human genomic DNA digested by nine different restriction enzymes. Five RFLPs, involving Asp700, PvuII, XbaI, and EcoRV sites, were detected, and Mendelian inheritance could be demonstrated. Since clones 9 and 10 are localized telomeric to the mutation-hot-spot region, their polymorphisms are thought to be very helpful as flanking markers for indirect carrier detection in families with a family history of DMD/BMD. Moreover, these RFLPs can be used for direct carrier detection or exclusion in families with patients showing a deletion/duplication in the region of p9 or p10.

Blotting, Southern↗

[Hypoglycemia in children with diabetes treated with human or porcine insulin].

If hypoglycemia unawareness in diabetes is related to human insulin, its use would mean an increased risk of unconscious hypoglycemia. In a prospective study in 59 children treated from onset of diabetes by either human or porcine insulin of equal purity for a mean observation period of more than 3 years, no significant difference in the incidence of hypoglycemic coma was detected: 9/29 (31%) of the children treated by human insulin compared to 8/30 (27%) of those treated by porcine insulin had 1 or more severe hypoglycemic episodes. At the time of the first coma there was no significant difference in age, duration of diabetes, insulin dose, or HbA1 between the groups. Thus, human insulin is not considered to be an additional risk factor for the development of hypoglycemic coma in diabetic children.

Adolescent↗

Increased prevalence of fetal haemoglobin in type 1 (insulin-dependent) diabetes mellitus.

Fetal haemoglobin levels were measured in 106 patients with Type 1 (insulin-dependent) diabetes mellitus during a period of two to three years. In 15 patients (14.1%) increased fetal haemoglobin levels (greater than 0.5%), determined by high pressure liquid chromatography, were found in contrast to 3% in a healthy control group (n: 100) of equal age distribution. In children aged over 6 years, elevated fetal haemoglobin levels were measured in 13 diabetic patients (13.3%) in contrast to none of the control group. There was no correlation between fetal haemoglobin levels and duration of diabetes, diabetic control (glycated haemoglobin) and dosage of insulin (U.kg-1, day-1). The 15 patients had a younger mean age at onset of diabetes (5.6 years) than a sex and age matched control group of diabetic patients without increased fetal haemoglobin levels (7.4 years, p less than 0.05). Longitudinal assessment revealed a significant decline of fetal haemoglobin levels with age (p less than 0.005) but a further increase in fetal haemoglobin levels were found in adolescent patients (n: 2). These data indicate a possible effect of insulin-treatment on delaying transition from fetal to adult haemoglobin synthesis or on reactivation of fetal haemoglobin production.

Adolescent↗

Intermittent microalbuminuria in children with type 1 diabetes mellitus without clinical evidence of nephropathy.

Microalbuminura (MA) was determined in 127 children and adolescents (age 3-21 years) with type 1 (insulin-dependent) diabetes mellitus. Patients with clinical evidence of long-term complications or macroproteinuria were excluded. Urinary albumin excretion was measured in a nocturnal 12-h collection and correlated with the albumin/creatinine ratio of a urine sample freshly voided on the morning immediately following the collection. The patients were divided into group A (n = 83, age less than 16 years, duration of diabetes 1-13 years, mean 4.4) and group B (n = 44, age greater than 16 years, duration of diabetes 1-19 years, mean 8.7) and compared with appropriate controls. MA above 15 micrograms/min was present in 11 of 83 (13.3%) patients in group A and in 7 of 44 (15.9%) in group B. In a repeat urine collection at least 3 months later elevated MA persisted in 1 of 11 (group A) and in 4 of 7 (group B) patients. There was no correlation between increased MA in a 12-h urine collection and the albumin/creatinine ratio in a subsequently voided urine sample. MA was not strictly dependent on age, sex, duration of diabetes, haemoglobin A1, mean arterial blood pressure, plasma creatinine, creatinine clearance or serum beta-2-microglobulin. Further systematic studies and careful follow up are necessary to appraise whether intermittent MA is indeed an early manifestation of incipient kidney disease in children with type 1 diabetes.

Adolescent↗

Comparison of fructosamine and glycated haemoglobin in children with type 1 (insulin-dependent) diabetes mellitus.

In six children (age: mean 8.4 years, range 2.2-12.6 years) with newly diagnosed Type 1 (insulin-dependent) diabetes mellitus, plasma fructosamine and glycated haemoglobin (HbA1) were compared in respect to their disappearance during the first month after diagnosis during well controlled glycaemia. The disappearance of the surplus plasma fructosamine and HbA1 was calculated applying exponential equations. The estimated half-lives of fructosamine (mean 57.2 days, range 40.7-77 days) and HbA1 (mean 59.7 days, range 43.3-82 days) were not significantly different, a finding which is left unexplained.

Child↗

[Transcutaneous determination of bilirubin in the neonatal department: an analysis of its uses].

2000 newborns were evaluated before and 2000 after the introduction of transcutaneous bilirubinometry, with regard to frequency and methods of bilirubin determination. The number of blood sampling procedures was reduced by 79%. Transcutaneous bilirubinometry proves to be a safe method if correlation curves between the transcutaneous indices and the serum bilirubin of the individual nursery population are used together with set rules as to the indications for the controls by blood sampling (Recommendations of the Swiss Neonatology Group). A charge of sFr. 5.- to 7.- for each transcutaneous bilirubin evaluation is justified with regard to the reduced laboratory investigations.

Bilirubin↗