Experimental stress fractures of the tibia. Biological and mechanical aetiology in rabbits

We have shown that stress fractures can be induced in the tibial diaphysis of an animal model by the repeated application of non-traumatic impulsive loads. The right hind limbs of 31 rabbits were loaded for three to nine weeks and changes in the bone were monitored by radiography and bone scintigraphy. The presence of stress fractures was confirmed histologically in some cases. Most animals sustained a stress fracture within six weeks and there was a positive correspondence between scintigraphic change and radiological evidence. Microscopic damage was evident at the sites of positive bone scans. The progression, location, and time of onset of stress fractures in this animal model were similar to those in clinical reports, making the model a useful one for the study of the aetiology of stress fractures.     

Evaluation of non-invasive blood pressure measurement by the Finapres method at rest and during dynamic exercise in subjects with cardiovascular insufficiency

The accuracy and precision of the Finapres in recording rest and exercise blood pressure compared with the intra-arterial (aortic and brachial) and random-zero sphygmomanometer methods was assessed in 84 ischaemic patients in three different studies. Firstly, comparison at rest with the aortic intraarterial pressure in 50 ischaemic patients demonstrated that the Finapres systolic (136.5 ± 21.1 vs. 129.3 ± 19.0 mmHg;p < 0.001) and mean (92.4 ± 13.4 vs. 90.7 ± 11.4 mmHg;p < 0.001) arterial pressures were higher and diastolic pressures lower (70.4 ± 11.5 vs. 71.5 ± 9.8 mmHg;p < 0.001). The reproducibility of the Finapres and invasive method was similar for systolic (4.6% vs. 4.0%), diastolic (2.8% vs. 2.7%) and mean (3.3% vs. 3.0%) blood pressures. Second, in seven subjects studied twice at rest and during 4 min supine bicycle exercise, the exercise increase in blood pressure was greater on the Finapres compared with the brachial intra-arterial pressure (systolic +10.2 ± 6.3 vs. +3.6 ± 9.8 mmHg; diastolic +9.6 ± 11.1 vs. +0.2 ± 2.1 mmHg;p = 0.02 for each); however, at steady-state the peak/trough differences in pressure between the methods were similar. Thirdly, compared under rest conditions, to random zero sphygmomanometer (RZO), the Finapres systolic pressure was higher (6.8 ± 3.5 mmHg) and diastolic pressure lower (–6.0 ± 1.9 mmHg). During upright bicycle exercise, the difference between the Finapres and RZO in systolic blood pressure increased at each level of exercise (+14.3 ± 4.2, +17.9 ± 4.0 and +22.2 ± 4.1 mmHg respectively at each exercise stage:p < 0.01). For RZO, diastolic blood pressure fell as exercise workload increased whereas Finapres diastolic blood pressure increased on exercise (3.1 ± 2.6, 7.0 ± 2.1 and 8.1 ± 2.0 mmHg respectively:p < 0.01). Thus there were systematic differences between the values recorded by the Finapres and proximal blood pressure methods and limited agreement in the rest to exercise increments related to light exercise. Calibration of the Finapres values in terms of the other methods is limited by the variable relationship to these related changes in arterial distensibility.     

EEG findings in hypomelanosis of Ito.

The EEG findings in 15 children with Hypomelanosis of Ito have been reviewed and related to the clinical and CT scan data. Although no consistent electroclinical associations were found in the group as a whole, there was some association between the presence of abnormal rhythmic EEG activity and the radiological appearances of neuronal migration defects. In addition, the possibility is raised that there may be a distinctive sub-group of children with Ito's syndrome who present with an early onset of intractable seizures and who have a neuronal migration defect.     

A new fluorescent mitochondrial antibody: Disease association

The case notes of 34 patients whose sera contained an antibody giving an unusual immunofluorescent staining pattern were reviewed. This antibody designated M2(1) gave a slightly different pattern of staining on composite sections of rat liver, kidney and stomach from the primary biliary cirrhosis associated M2 antimitochondrial antibody. Anaemia was present in 10 patients, endocrine disease in 7 patients and autoimmune liver disease in 6 patients. We did not find the presence of M2(l) antibody to be of specific diagnostic significance. Although the M2(l) antibody is rare, caution is required in order to avoid confusion between this antibody and the M2 antimitochondrial antibody of primary biliary cirrhosis.     

Histopathology of the teeth in segmental odontomaxillary dysplasia: new findings

Histological examination of the deciduous teeth in two cases of segmental odontomaxillary dysplasia (SOMD) showed fibrous enlargement of the pulps, an irregular pulp/dentine interface displaying many pseudoinclusions and pulp stones. There were tubular defects in the coronal dentine from pulp horn to cusp tip, an irregular tubular structure to the circumpulpal dentine of the apical half, a focally deficient odontoblast layer and widespread external resorption. Together with the clinical features of unilateral maxillary enlargement, upper alveolar expansion in the distal segment, increased spacing and delayed eruption of the deciduous molars and absence of premolar teeth, these histological appearances allow distinction of this condition from fibrous dysplasia (FD), segmental hemifacial hypertrophy (SHH) and regional odontodysplasia (ROD).     

Complications of the Kock pouch

Over the past 41/2 years, 395 consecutive Kock pouch procedures have been performed by the urology faculty at the University of Southern California School of Medicine as an alternative to conventional cutaneous urinary diversion. This article reviews the early and late complications experienced in the 386 patients surviving the operation and describes in detail modifications in surgical technique designed to reduce the complication rate and the subsequent need for re-operation. We remain convinced that construction from ileum of a low-pressure, high-capacity internal reservoir with continent and nonrefluxing valves as originally described by Kock remains the ultimate technique for patients requiring permanent urinary diversion or for those requiring conversion from a pre-existing form of diversion.     

Fixed drug eruption to Tylenol: report of two cases and review of the literature.

Fixed drug eruptions due to Tylenol (paracetamol, acetaminophen) are very rare. The authors report two additional cases and review the literature.