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Biomedical subjects

N Peters

Publications and source records attributed to N Peters.

At least 37 records · Page 2Linked to original sources

Organization of the human tumour necrosis factor receptor-associated factor 1 (TRAF1) gene and mapping to chromosome 9q33-34.

A new family of signal transducing proteins, associated with members of the tumour necrosis factor receptor (TNFR) superfamily, has recently been identified. The structural hallmark of these molecules is a novel C-terminal homology region of 230 bp designated as TRAF (TNF receptor-associated factor) domain, which is involved in a variety of specific protein-protein interactions. To elucidate the human TRAF1 gene structure for identification of potential regulatory elements, a set of genomic polymerase chain reaction (PCR) fragments was generated, which comprised the whole coding region of TRAF1. These fragments were cloned and partially sequenced to map splicing sites. The human TRAF1 gene was found to have a total length of approx. 12 kb. It is split into six exons, four of which encode for parts of the TRAF domain. Analysis of the genomic structure of the TRAF domains of human TRAF2 and 3 suggests that these domains are also encoded by several exons. The putative promotor region of the TRAFI gene was isolated by use of a PCR-based genomic walking approach. Fluorescence in situ hybridization was used to map this gene to chromosome 9q33-34.

Base Sequence↗

Renal tubular function in children and adolescents with Gitelman's syndrome, the hypocalciuric variant of Bartter's syndrome.

Renal tubular function was studied in 14 patients with Gitelman's syndrome and 14 control subjects. Apart from the biochemical hallmarks of Gitelman's syndrome, namely alkalaemia, hyperbicarbonataemia, hypokalaemia, hypomagnesaemia (with increased magnesium over creatinine ratio), increased urinary chloride over creatinine ratio, and low urinary calcium over creatinine, the patients were found to have hyperproteinaemia, hypochloraemia, high total plasma calcium concentration, reduced plasma ionized calcium concentration, and high urinary sodium excretion. A statistically significant negative linear relationship between plasma magnesium concentration and magnesium excretion corrected for glomerular filtration was observed in patients. The fractional calcium clearance and the urinary excretion of calcium corrected for glomerular filtration was significantly decreased in patients. In patients the urinary osmolality after overnight water deprivation ranged from 526 to 1067 mmol/kg. Glucosuria and aminoaciduria were similar in patients and controls. The results of the study demonstrate the renal origin of hypomagnesaemia and hypocalciuria in Gitelman's syndrome. The failure to demonstrate hyperaminoaciduria, hyperglucosuria, hyperphosphaturia, hyperuricosuria, and severely impaired urinary concentrating ability provide evidence for a defect residing in the distal convoluted tubule.

Adolescent↗

[Utilization of pacifiers: distribution, causes and sequelae].

UNLABELLED: A survey of 293 children in a pediatric practise showed that in 80% a pacifier was used. This spread is the result of a distribution in the hospital at birth on the one hand and appreciation of its tranquilizing effect by the parents on the other hand. According to the parents, the use of a pacifier is a habit. A sucking child can, thus, restore its emotional equilibrium. This self-control reappears in certain situations. With time the child learns to control its behavior by other means. Only few children have difficulties in giving up this habit. Children using an alternative to the pacifier have more dental and jaw deformations than those using a pacifier. Dental pacifiers cause far less deformations than the other types. CONCLUSIONS: 1. Children who suck their fingers should be given a pacifier. 2. One should give a pacifier to babies with emotional problems up to the age of 6 months. Later on, an object harmless to the teeth should be given. 3. A pacifier should only be used if really necessary.

Child Behavior↗

Diagnosis and management of giant intrasacral schwannoma.

Giant intrasacral schwannoma is a rare cause of a retrorectal mass in an adult patient. Only 21 such tumors have been reported. The diagnosis of this intraosseous nerve sheath tumor is heralded by its minimal symptoms in relation to its often striking radiographic findings and is verified by its unique morphology. Surgical resection is complex because of its anatomic location and propensity for local recurrence. The need for adequate tumor removal must be balanced against the preservation of nerve function. The presentation, diagnosis, and management of intrasacral schwannomas are reviewed, as exemplified in this case presentation and literature review.

Adolescent↗

Chemodectoma of the head and neck: results of treatment in 84 patients.

Eighty-four patients with chemodectoma of the head and neck presented to the Royal Marsden Hospital between 1949 and 1985. For tumors arising at the skull base (glomus jugulare and glomus tympanicum) 46 were treated with radiotherapy alone resulting in an actuarial local control rate of 73% at 25 years; 13 were treated with surgery plus radiotherapy with no recurrences during a median follow-up of 9 years; 4 had surgery alone but all recurred by 7 years. For tumors of the soft tissues of the neck (carotid body and glomus vagale) 13 were treated with surgery alone with an actuarial control rate of 54% at 15 years; 4 were treated with radiotherapy which resulted in local control at 1, 2, 8 and 11 years; and one patient who received both surgery and radiotherapy remained controlled at 1 year. Although comparison between radiotherapy and surgery in terms of tumor control is not simple, the case is argued for more frequent use of radiotherapy at all sites. This case is strengthened by minimal morbidity from radiotherapy in doses which appear effective: in the range of 45-50 Gy in 25 daily fractions over 5 weeks.

Adult↗

Biological significance of cell cycle kinetics in 128 standard risk newly diagnosed patients with acute myelocytic leukemia.

Bromodeoxyuridine (BrdU) was administered to 128 newly diagnosed patients with standard risk acute myelocytic leukaemia (AML) for cell cycle measurements. Labelling indices (LI) were obtained from both the bone marrow aspirate (BMasp) and biopsies (bx) and durations of S-phase (Ts) and total cell cycle time (Tc) were measured by double-labelling the S-phase cells in vitro with tritiated thymidine. Median LI BMasp was 8% and from BMbx was 25%. The median Ts was 12 h (range 3.1-35 h) and Tc was 48 h (range 11.5-211 h). All patients received induction therapy with a combination of cytosine arabinoside and an anthracycline. Outcome of therapy or FAB type were not related to cell cycle characteristics. Patients with above median LI BMasp, however, had longer remission durations (P = 0.03) as did patients with above median Ts (P = 0.03) and Tc (P = 0.03). Upon longer follow-ups, even some of the patients with slowly cycling myeloblasts have relapsed (log rank P = 0.453 and 0.203 for Ts and Tc respectively). We conclude that patients with rapidly cycling cells tend to relapse faster; however, slowly cycling nature of myeloblasts is not associated with curability.

Adult↗

Elderly male spouses as caregivers--toward an understanding of their experience.

Male caregivers have difficulty assuming personal and household responsibilities; they seem to cope by focusing on the caregiving tasks and projects, establishing daily routines, and carving out their own territory in the home. To facilitate effective interventions, nurses should ascertain the elderly male spouse's meaning of caregiving. This would enable practitioners to foster the caregiver's strengths and provide support in those areas where burden or difficulties are experienced. Husbands as caregivers were more likely than wives to seek the help of formal providers and receive more informal support. Male caregivers tend to not participate in support groups. Before making a referal, nurses should ensure the group is geared to the special needs of the man.

Aged↗

Anxiety, type A personality and endocrine responses to surgery.

Twenty-seven patients underwent major abdominal surgery. Trait Anxiety and Type A personality were measured pre-operatively, and plasma cortisol, adrenaline and noradrenaline were measured pre-, per- and post-operatively. Anxiety correlated positively with noradrenaline but negatively with cortisol and adrenaline. Type A also showed opposite correlations with adrenaline and noradrenaline.

Adolescent↗

The relationship of preoperative distress to endocrine and subjective responses to surgery: support for Janis' theory.

To test Janis' theory that preoperative worry can improve postoperative recovery, endocrine and subjective responses were measured in 27 patients undergoing major abdominal surgery which entailed threat to their health or longevity. Questionnaires to assess emotional and somatic state were completed preoperatively and for 7 days postoperatively. Plasma cortisol, noradrenaline, adrenaline, and glucose were measured pre-, per-, and postoperatively. Preoperatively, noradrenaline correlated positively with pain and distress, and adrenaline negatively. Postoperatively, endocrine levels and distress were not clearly related. Nevertheless, preoperative pain negatively correlated with postoperative adrenaline and cortisol levels. This, and the negative correlation between preoperative distress and postoperative pain are consistent with Janis' theory. In addition, we found that the longer patients waited on the day of surgery, the greater were the cortisol, noradrenaline, and glucose responses.

Adolescent↗

Expression of the precore region of an avian hepatitis B virus is not required for viral replication.

The core-antigen-coding region of all hepadnaviruses is preceded by a short, in-phase open reading frame termed precore whose expression can give rise to core-antigen-related polypeptides. To explore the functional significance of precore expression in vivo, we introduced a frameshift mutation into this region of the duck hepatitis B virus (DHBV) genome and examined the phenotype of this mutant DNA by intrahepatic inoculation into newborn ducklings. Animals receiving mutant DNA developed DHBV infection, as judged by the presence in hepatocytes of characteristic viral replicative intermediates; molecular cloning and DNA sequencing confirmed that the original mutation was present in the progeny genomes. Infection could be efficiently transmitted to susceptible ducklings by percutaneous inoculation with serum from mutant-infected animals, indicating that infectious progeny virus was generated. These findings indicate that expression of the precore region of DHBV is not essential for genomic replication, core particle morphogenesis, or intrahepatic viral spread.

Animals↗

Ventricular arrhythmias complicating weight reduction therapy in a patient with a prolonged QT interval.

Serious ventricular arrhythmias are known to occur in patients with long QT intervals. We describe a case of torsade de pointes occurring in a patient with a prolonged QT interval while taking a 1000 calorie diet, diethylpropion hydrochloride (Tenuate Dospan) and bendrofluazide. In patients with long QT intervals, hypokalaemia and drugs which further delay repolarization may facilitate the development of life threatening arrhythmias.

Adult↗

Peripheral glucose uptake in young men with myocardial infarction.

Forearm glucose uptake (FGU) was studied during 100 g oral glucose tolerance tests (GTT) in nonobese, nondiabetic men who had suffered a myocardial infarction (MI) at or before the age of 40, and the results compared with the response in age-matched normal men. In the MI group the rise in both glucose and insulin concentrations after glucose loading was similar to that in normal subjects, although in the former, peak levels tended to be slightly higher. Concomitant FGU, however, was significantly greater in the MI group than in control subjects in the period 0-90 min and in the test as a whole (0-180 min). The results show that at least in some nondiabetics suffering MI at an early age hyperinsulinism is not a feature and peripheral tissue sensitivity is increased.

Adult↗

Temperature-dependent growth and regression of epidermal tumors in the european eel (Anguilla anguilla L.).

The population of eels in the Elbe estuary showed a high rate of affliction with epidermal papillomas. Distinct seasonal fluctuations were observed in the frequency of occurrence and tumor size. In spring and autumn, the frequency was low, and the tumors were relatively small. In summer, the tumors reached a maximum in both frequency and size. A distinct influence of water temperature on tumor growth was demonstrated experimentally. Summer temperatures of 15--22 degrees C caused very rapid growth. In the field and in the laboratory, the tumors exhibited a fourfold increase in average volume within 3 months. These fast-growing neoplasms had certain relatively uniform histologic features. The tumor cells were separated by wide intercellular spaces. The basal layer was composed of tall columnar cells, while the surface layer was composed of slightly flattened cells. Winter water temperatures (5--10 degrees C) inhibited tumor growth and even caused tumor regression. In 3 months, the papillomas shrank to half of their initial size. Histologic and ultrastructural examinations revealed signs of tissue degeneration: necrobiotic processes in the epidermal region, cellular and nuclear polymorphisms, dissolution of membranes, loss of cell integrity, and loosening and reduction in size of the basal cell layer.

Anguilla↗

Geographic variations in tumor prevalence among marine fish populations.

A global epidemiological study on the frequency of skin papillomas among various flatfish species (Pleuronectids), papillomas of eels and the virus induced lymphocystis disease has revealed particular distribution patterns. Skin papillomas are prevalent among at least 20 flatfish species of the northern Pacific Ocean, Bering Sea, Sea of Okhotsk, and Japan Sea but appear to be absent from the Atlantic, North Sea, and the Caribbean Sea. The opposite is found for lymphocystis, which is common among flatfish species of the Atlantic shores of Europe and North America. Similarly the skin papillomas of eels are restricted to relatively small region along the European coast extending from the Baltic countries to Denmark, Germany and Holland. Superimposed on this global distribution pattern are local variations in tumor prevalences which can vary from about 58% to 0.01%. The geographic distribution pattern points to the existence of areas around the globe in which flatfish or eels are able to develop skin papillomas. Outside these areas of "potential skin papilloma risk," flatfish and eel populations are not afflicted with papillomas even if they inhabit estuaries or rivers with a high man-made or naturally-occurring pollution.

Animals↗

Neurosurgical microvascular bypass for stroke.

A review of the present status of neurosurgical vascular bypass for problems of cerebrovascular occlusive disease is presented. In 70 patients who have undergone operations by one surgical team, the results are most encouraging in cases of transient ischemic attacks with hemodynamic lesions previously considered inoperable or inaccessible in the cerebral vasculature. The morbidity rate is acceptable and the present operative mortality rate is 1.4 percent.

Aged↗