Capillary supply in relation to myosin heavy chain fibre composition of human intrinsic tongue muscles.

The capillary supply and myosin heavy chain (MyHC) composition of three different intrinsic tongue muscles was analysed in the anterior and posterior regions of the human tongue with biochemical and immunohistochemical techniques. Mean capillary density for the whole tongue was 796 ± 82 cap/mm², without regional differences. The overall number of capillaries around each fibre (CAF) was higher in the posterior than in the anterior region (2.5 vs. 2.1, p = 0.009). However, correcting for regional differences in fibre size, CAF per fibre area was higher in the anterior region (4.3 vs. 3.0, p < 0.001). Muscle fibres containing fast MyHCs predominated in the anterior region (78.7%), consisting of MyHCIIa (58.5%), MyHCIIx (1.0%), MyHCIIa+MyHCIIx (11.3%) and MyHCI+MyHCIIa (7.9%). Fibres containing slow MyHC predominated in the posterior region (65.2%), consisting of MyHCI (45.5%) and MyHCI+MyHCIIa (19.7%). A minor fibre population (<2%) contained unusual MyHC isoforms, namely MyHC foetal, MyHC slow-tonic, MyHC α-cardiac or MyHC embryonic. The microvascularization of the human tongue was twice as high as in human limb muscles. Regional similarities in capillary supply, but differences in fibre phenotype composition, suggest that human tongue muscle fibres are fatigue resistant independently of MyHC content. High frequency of hybrid fibres, that is fibres co-expressing two or more MyHC isoforms, indicates a wider spectrum of fibre contractile properties than in limb muscles. In conclusion, human intrinsic tongue muscles showed internal specialization in distribution of MyHC isoforms and capillary supply, but not in the expression of unusual MyHCs.

Dose assessment analogies.

Assessments of radiation detriment are based on the absorbed dose in the organs and tissues of interest, assuming a linear, nonthreshold dose--response relationship for the induction of cancer or genetic effects at low doses. Similar assessments may be made for nonradioactive, mutagenic, or carcinogenic substances, in which case the time integral of the local tissue concentration of the substance may be the quantity which would correspond to the radiation dose. It can be shown that the assessment then involves calculations which are very similar to those made in the assessment of radiation detriment. It is suggested that an attempt should be made to make such assessments for nonradioactive pollutants, in order to provide a more appropriate basis for comparisons with radiation detriments. In the assessment of the detriment from inhaled substances, the overall collective intake commitment is simply the total amount of each substance ever to be inhaled, irrespective of when or where. This quantity might be assumed to be proportional to the total detriment in form of lung cancer.

Liver toxicity of ionic (Diatrizoate) and nonionic (C-29) contrast materials: effects of serum enzymes after hepatic artery injection in the rat.

Catheters were placed in the retrograde direction in the surgically exposed gastroduodenal arteries of rats. There was an early postoperative mortality of one-third of the animals. The catheter was exteriorized at the tail and was used for arterial perfusion of the liver with one experimental, nonionic contrast medium (C-29) and one ionic contrast medium (diatrizoate). Both contrast media (370 mg I/ml) were injected in a dose of 4 ml/kg rat. The contrast medium injections caused no significant changes in serum levels of the enzymes ALAT, ASAT, or GT.

Oscillation of pain intensity during adenosine infusion. Relationship to beta-endorphin and sympathetic tone.

Adenosine is a neuromodulator with both excitatory and inhibitory effects dependent in part upon preconditions; it can act as an algesic or an analgesic agent. Previously we found variations of pain intensity during constant infusion of adenosine. We therefore quantified pain intensity during constant infusion of adenosine at a rate of 140 microg/kg/min intravenously in healthy volunteers, placebo controlled, double blind, and the relation to hemodynamic, vasomotor and sudomotor responses of the sympathetic nervous system and to the role of peripheral beta-endorphin response. The perceived chest pain during adenosine infusion showed an oscillatory pattern. Painful periods of about 30s were interrupted by painfree periods, and pain was always preceded by an increase in vasomotor sympathetic activity and by increased sudomotor activity. Plasma beta-endorphin values were heterogenous but exhibited an increase during infusion.

Activity-induced pain in rheumatoid arthritis functional class II and its relations with demographic, medical, functional, psychosocial, and work variables. Result of a survey in Bollnäs Medical District, Sweden, II.

One aim of this study was to describe inflammatory activity, joint destruction, work status, and demographic factors in a group of 69 American Rheumatism Association functional class-II rheumatoid arthritis patients: 56 women and 13 men, mean age 54 years (SD 11), mean symptom duration 14 years (SD 11). Another aim was to determine correlations between activity-induced pain and other variables. Patients were assessed with Ritchie's articular index, Larsen's radiologic index, and laboratory tests. Deformity in hands and knee joints, and grip strength, were determined. Results from earlier investigations of functional impairment and psychosocial capacity were also used. Of the patients, 4% had high inflammatory activity. Joint erosions were found in between 4% (knee joints) and 55% (wrists) of the joints examined. Of the patients aged less than 65, 43% were working. Activity-induced pain was related with work status (p = 0.0002). It also correlated significantly (p less than or equal to 0.01) with inflammatory activity (r(s) = 0.34), but not with joint destruction (r(s) = 0.21).

Phantom limb pain and etiology of amputation in unilateral lower extremity amputees.

The relationships between phantom limb pain and both the etiology of amputation (blood clots, nonclot diabetes, and miscellaneous) and the occurrence of gangrene and/or infection were investigated in 92 unilateral lower extremity (LE) amputees who were seen sequentially. There were 55 above-knee (AK) and 37 below-knee (BK) amputations in 61 men and 31 women. The mean age was 51.4 years. The blood-clot etiology had the highest levels of phantom pain both pre- and postrehabilitation, the longest time interval between amputation and prosthetic fitting, and the greatest number of medical conditions. The nonclot diabetes and miscellaneous etiologies followed in order. A history of gangrene and/or infection was associated with higher levels of pain and longer time interval between amputation and prosthetic fitting.

The influence of degradable starch microspheres on liver uptake of 5-fluorouracil after hepatic artery injection in the rat.

The effect of degradable starch microspheres (DSM) on the distribution of 5-fluorouracil (5-FU) after hepatic artery injection was studied in normal rats. Carbon-14-labelled 5-FU was injected separately or together with DSM into the hepatic artery. Radioactivity was measured in liver tissue, bile, peripheral blood, and urine. When microspheres were added, the liver uptake of 5-FU was increased; its peak concentration in peripheral blood decreased, as did the early urinary excretion of radioactivity. The addition of degradable starch microspheres to hepatic artery injections of cytostatic drugs might be of value in increasing the drug concentration in tumour tissue and reducing systemic toxicity.

Compressive orthotics in the treatment of asymmetric pectus carinatum: a preliminary report with an objective radiographic marker.

BACKGROUND/PURPOSE: Pectus carinatum (PC) traditionally has been managed with surgical reconstruction. Compressive orthosis also has resulted in subjective improvement in this defect. The goal of the authors was to develop an alternative brace and an objective radiographic marker to monitor the effects of chest wall compression on sternal protrusion. METHODS: Baseline chest computed tomography (CT) scans were obtained for 5 teenage boys with chondrogladiolar type of PC. The angle at the point of greatest sternal rotation was measured as the baseline deformity. Compressive orthosis was initiated using a custom-fitted brace. Follow-up chest CT scans were obtained to document change in sternal rotation. RESULTS: One patient was lost to follow-up after 6 months with subjective improvement. Another opted for surgical correction after 3 months, having shown a 16% decrease in sternal rotation preoperatively. Two patients showed subjective improvement corroborated by 33% and 44% decreases in sternal rotation. The fifth patient, who discontinued bracing after 1 month, showed a 25% increase 6 months later. CONCLUSIONS: Preliminary results indicate a potential role for compressive orthosis in the management of pectus carinatum. The objective radiographic marker described may be used to monitor the effects of growth or treatment with compressive orthosis.

Radiation protection--a look to the future: ICRP perceptions.

The author was invited to talk about ICRP perceptions of a look to the future. Many questions will be addressed when the International Commission on Radiological Protection (ICRP) initiates a revision of its basic recommendations from 1977, which were published in ICRP Publication 26. This process will take several years, and in the meantime the author does not expect any major changes in the present policy of the commission. It is still too early to predict the commission's future policy but, to some extent, present trends might be extrapolated, as indicated in this discussion.

In radiological protection, the protection quantities should be expressed in terms of measurable physical quantities.

It is somewhat of a truism that is expressed in the often quoted statement that you can't go home again. In the days when life was simpler, we could assume that a measurement performed with a portable survey instrument yielding a value for exposure rate in terms of roentgens/hour was a sufficient approximation to the value for the dose equivalent rate or absorbed dose rate at a point in a radiation field. As our understanding of radiological protection grew more sophisticated, we found it necessary to introduce additional rigor into the definitions of the radiation protection quantities. As mentioned earlier, we demand a lot from the definitions of these quantities. They need to satisfy many conditions, perhaps too many. When they are examined from the point of view of a metrologist, they may be considered to be deficient in many respects. When they are viewed by a radiobiologist, they may appear to be naïve or overly simplistic. A radiation protection technologist at a nuclear power plant may have difficulty understanding their sometimes-subtle implications. The ICRU and ICRP have worked for quite some time to incorporate all the necessary requirements into the definitions of the operational and protection quantities. From the arguments of our debaters, one might conclude that after careful consideration of past developments, additional refinements will be devised in the future.