Type V osteogenesis imperfecta: a new form of brittle bone disease.

Osteogenesis imperfecta (OI) is commonly subdivided into four clinical types. Among these, OI type IV clearly represents a heterogeneous group of disorders. Here we describe 7 OI patients (3 girls), who would typically be classified as having OI type IV but who can be distinguished from other type IV patients. We propose to call this disease entity OI type V. These children had a history of moderate to severe increased fragility of long bones and vertebral bodies. Four patients had experienced at least one episode of hyperplastic callus formation. The family history was positive for OI in 3 patients, with an autosomal dominant pattern of inheritance. All type V patients had limitations in the range of pronation/supination in one or both forearms, associated with a radiologically apparent calcification of the interosseous membrane. Three patients had anterior dislocation of the radial head. A radiodense metaphyseal band immediately adjacent to the growth plate was a constant feature in growing patients. Lumbar spine bone mineral density was low and similar to age-matched patients with OI type IV. None of the type V patients presented blue sclerae or dentinogenesis imperfecta, but ligamentous laxity was similar to that in patients with OI type IV. Levels of biochemical markers of bone metabolism generally were within the reference range, but serum alkaline phosphatase and urinary collagen type I N-telopeptide excretion increased markedly during periods of active hyperplastic callus formation. Qualitative histology of iliac biopsy specimens showed that lamellae were arranged in an irregular fashion or had a meshlike appearance. Quantitative histomorphometry revealed decreased amounts of cortical and cancellous bone, like in OI type IV. However, in contrast to OI type IV, parameters that reflect remodeling activation on cancellous bone were mostly normal in OI type V, while parameters reflecting bone formation processes in individual remodeling sites were clearly decreased. Mutation screening of the coding regions and exon/intron boundaries of both collagen type I genes did not reveal any mutations affecting glycine codons or splice sites. In conclusion, OI type V is a new form of autosomal dominant OI, which does not appear to be associated with collagen type I mutations. The genetic defect underlying this disease remains to be elucidated.

Analysis of the accuracy of continuous thermodilution cardiac output measurement. Comparison with intermittent thermodilution and Fick cardiac output measurement.

OBJECTIVE: To evaluate the accuracy of cardiac output measurement obtained by a new continuous thermodilution cardiac output (CCO) pulmonary artery catheter compared to intermittent thermodilution (TCO) and the direct Fick method. DESIGN: Prospective open trial. SETTING: University hospital, intensive care unit. PATIENTS: 23 patients (15 surgical, 8 non-surgical) were monitored with the Intellicath pulmonary catheter. Cardiac output was evaluated by the three methods every 4 to 6h as long as the pulmonary artery catheter was necessary (8-96 h). RESULTS: The correlation coefficient between CCO and TCO was 0.92, no systematic bias was observed, and the relative error increased from 13.9% for a cardiac output of 21/min to 23.7% for an output of 101/min. When comparing CCO and Fick, the correlation coefficient was 0.89, no bias was detected, and the relative error increased from 20.4% for outputs of 21/min to 27.2% for outputs of 101/min. CONCLUSIONS: CCO provides clinically acceptable measurements. At high cardiac outputs, the difference with other methods increases and the results must be cautiously interpreted.

An easier method for percutaneous endoscopic gastrojejunostomy tube placement.

BACKGROUND: The current procedures for percutaneous endoscopic gastrojejunostomy (PEG-J) tube placement require fluoroscopy and are time consuming. We describe a new, simple method. METHODS: Ten patients had a PEG-J tube placed by the new method. After placement of a percutaneous endoscopic gastrostomy (PEG) tube using standard technique, the PEG tube was pushed up to the pylorus to make it easier to place the jejunal tube into the duodenum without looping in the stomach. Fluoroscopy was not used. The position of the tube was confirmed by a plain x-ray film of the abdomen. RESULTS: The mean time required for PEG placement and jejunal tube placement was 9.0 and 8.2 minutes, respectively. In all patients the tip of the jejunal tube was at the ligament of Treitz. In one patient the jejunal tube formed a loop in the duodenum, but this was reduced by spontaneous forward migration. In another patient, the tube migrated back into the stomach after 1 week. CONCLUSION: The method described allows easier PEG-J placement without fluoroscopy.