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Biomedical subjects

P Blom

Publications and source records attributed to P Blom.

13 recordsLinked to original sources

Lower levels of plasma 25-hydroxyvitamin D among young adults at diagnosis of autoimmune type 1 diabetes compared with control subjects: results from the nationwide Diabetes Incidence Study in Sweden (DISS).

AIMS/HYPOTHESIS: Low plasma vitamin D concentrations may promote the development of type 1 diabetes. To test this hypothesis, we measured plasma 25-hydroxyvitamin D (25OHD) in young adults with type 1 diabetes. METHODS: The nationwide Diabetes Incidence Study in Sweden (DISS) covers 15- to 34-year-old people with newly diagnosed diabetes. Blood samples at diagnosis were collected during the 2-year period 1987/1988. Patients with islet antibodies (islet cell antibodies, GAD antibodies or tyrosine phosphatase-like protein antibodies) were defined as having autoimmune type 1 diabetes. Plasma 25OHD was measured in samples taken from 459 patients at the time of diagnosis, and in 138 of these subjects 8 years later. The results were compared with age- and sex-matched control subjects (n=208). RESULTS: At diagnosis, plasma 25OHD levels were significantly lower in patients with type 1 diabetes than in control subjects (82.5+/-1.3 vs 96.7+/-2.0 nmol/l; p<0.0001). Eight years later, plasma 25OHD had decreased in patients (81.5+/-2.6 nmol/l; p=0.04). Plasma 25OHD levels were significantly lower in diabetic men than in diabetic women at diagnosis (77.9+/-1.4 vs 90.1+/-2.4 nmol/l; p<0.0001) and at follow-up (77.1+/-2.8 nmol/l vs 87.2+/-4.5 nmol/l; p=0.048). CONCLUSIONS/INTERPRETATION: The plasma 25OHD level was lower at diagnosis of autoimmune type 1 diabetes than in control subjects, and may have a role in the development of type 1 diabetes. Plasma 25OHD levels were lower in men than in women with type 1 diabetes. This difference may be relevant to the high incidence of type 1 diabetes among young adult men.

Adolescent↗

Design, synthesis, and evaluation of N-aroyloxy-2-thiopyridones as DNA photocleaving reagents.

N-Benzoyloxy-2-thiopyridone (12) was shown to induce single-strand nicks in duplex DNA upon irradiation with visible light (lambda&350 nm). This finding led to the design of a series of compounds, in which an acridinyl nucleus was covalently linked to the N-benzoyloxy-2-thiopyridone unit. These conjugates (15, 16, 17 and 18) were synthesized and evaluated as novel DNA photocleaving reagents. Optimal photocleaving activity was observed for conjugate 16, in which a flexible polymethylene spacer of 4 carbons was used to connect the aminoacridine entity to the thiopyridone. This compound was shown to cleave DNA at low microM concentrations and was approximately two-orders of magnitude more efficient than the parent N-benzoyloxy-2-thiopyridone (12). Furthermore, the DNA cleavage ladders induced by 16 and 12 were found to be identical and of no significant sequence selectivity. These data suggest that the N-aroyloxy-2-thiopyridones can be used for the design of new DNA photocleaving reagents with potential use as 'photofootprinting agents' or as 'site-directed photonucleases'.

Autoradiography↗

Pedicle screw instrumentation for unstable thoracolumbar fractures.

We evaluated the results of short-segment pedicle screw instrumentation in 54 patients with unstable thoracolumbar fractures. Follow-up averaged 25 months (range, 11 to 36 months); 42 patients completed the study. Kyphosis was corrected by an average of 7 degrees at surgery and loss of correction averaged 5 degrees at the end of follow-up. On computed tomography, canal compromise averaged 57% preoperatively and 33% postoperatively. Complications included nerve root irritation due to screw penetration (1/42), screw breakage (2/42), and screw bending (6/42). Solid fusion was achieved in all cases at an average of 3 months. Of the 31 patients with normal neurologic function, 24 (77%) were pain-free at follow-up and had returned to previous levels of activity. We conclude that short-segment fixation with posterolateral fusion is effective in the treatment of unstable thoracolumbar fractures; it prevents progression of kyphotic deformity and neurologic deterioration, results in a stable fusion, and preserves uninvolved motion segments above and below the fracture site.

Adult↗

Increased plasminogen activator inhibitor and tissue plasminogen activator levels in subjects with electrocardiographic abnormality indicative of ischaemic heart disease: a cross-sectional study in Norsjö, Sweden.

The plasma levels of tissue plasminogen activator (tPA) antigen concentration and plasminogen activator inhibitor (PAI) activity were measured in a random sample of 260 subjects, 30, 40, 50, or 60 years of age. Electrocardiographic Q, ST and/or ST-T changes, suggestive of definite or possible ischaemic heart disease (IHD), were found in 21% of the 50-year-old and 37% of the 60-year-old subjects. As compared to subjects lacking such signs, plasma tPA and PAI levels were significantly increased in the 60-year-old group, and PAI tended to be increased in the 50-year-old group. Previous case-control studies, usually performed at specialized centres and liable to sampling biases, have suggested an association between increased PAI levels and ischaemic heart disease. This cross-sectional population study provides independent data that patients with electrocardiographic signs of IHD have increased levels of both PAI and tPA antigen.

Adult↗

Testicular histology after treatment with LH-RH analogue for carcinoma of the prostate.

Orchiectomy was performed in 16 patients because of progression of prostatic cancer despite adequate medical castration with goserelin (Zoladex, ICI) over a mean period of 17.6 months. Severe tubular atrophy was seen in the testes. The Leydig cells also showed signs of atrophy, a fact that may indicate a direct effect of goserelin on these cells. In 1 patient, however, orchiectomy was postponed for 3 months after cessation of medical castration. The serum testosterone had resumed almost normal values and testicular histology revealed intact spermatogenesis and apparently normal Leydig cells.

Aged↗

Intramuscular fluid pressure during isometric contraction of human skeletal muscle.

Intramuscular fluid pressures were recorded in the vastus medialis of seven healthy male volunteers. Pressures were measured simultaneously at three different sites in the muscle by a catheter-tip transducer with extremely low volume-displacement characteristics and by two extracorporeal transducers connected to slit catheters. All three recording systems gave qualitatively similar results provided the catheters had inner diameters exceeding 0.53 mm and allowed measurement of pressures lasting as short as 1 s. Wick catheters yielded slower responses than slit catheters. At any position intramuscular fluid pressure increased linearly with force up to maximal voluntary contraction (MVC). However, slopes of these curves varied greatly mainly because the pressure was also a linear function of the distance from the fascia. The highest recorded pressure was 570 Torr. At prolonged submaximal contractions intramuscular fluid pressure oscillated independent of contraction force. The linearity of both the pressure-force relationship and the pressure-depth relationship is compatible with a simple model based on the law of Laplace because the muscle fibers are curved during contraction in this muscle. It is hypothesized that blood flow is first compromised deep in the muscle where pressure is highest and in general at lower stress or tension in short bulging muscles with great curvature of the fibers compared with long slender ones.

Adolescent↗

Subcutaneous bronchogenic anomalies.

Two cases of congenital anomalies, one cyst and one sinus, presenting in the suprasternal notch are reported. No communication with deeper structures was found at surgery, and histology was compatible with previous descriptions of subcutaneous bronchogenic cysts. The literature is reviewed, and the similarity between these lesions and many cases of branchial fistula is stressed.

Branchioma↗

Primary retroperitoneal sarcomas. A review of 36 cases.

A retrospective study of 36 patients with primary retroperitoneal sarcomas treated at The Norwegian Radium Hospital is presented. The median age at presentation was 57 years. The most common presenting symptom was abdominal pain. Leiomyosarcoma and liposarcoma were the most common histologic subtypes. The median survival in the whole series was 25 months. Patients with completely resected tumors had a longer median survival (59 months) than patients with incomplete resection (16 months) but the difference was not statistically significant. The malignancy grade seemed to be the most important prognostic factor and patients with low grade tumors had a significantly better outlook than those with high grade tumors.

Abdomen↗