CONTINUOUS MEASUREMENT OF BLOOD GASES IN VIVO BY MASS SPECTROMETRY

Continuous analysis of oxygen and carbon dioxide tension inthe blood phase, over periods of 4–5 h, was carried outin the pulmonary artery (93 determinations in six anaesthetizeddogs) and in the aorta (29 determinations in four anaesthetizeddogs). Silastic-covered stainless steel catheters attached toa mass spectrometer were used. The mass spectrometer signalswere linearly related to the blood-gas tensions measured byconventional analysis. The mass spectrometer signals were calibratedin vivo by exposing the animals to high and low oxygen and carbondioxide tension. With such in vivo calibration the slopes ofthe straight line regressions for mass spectrometer Po₂ or Pco₂on Po₂ or Pco₂ by conventional analysis were comprised between0.944 and 1.031 while the standard error of the slopes werebetween 0.019 and 0.031. Deliberate reductions of cardiac outputhad little effect on the mass spectrometer readings.     

Double blind controlled study of treatment of atopic eczema with a preparation of hydrocortisone in a new drug delivery system versus betamethasone 17-valerate

A double blind study has shown that topical treatment with a new preparation of I% hydrocortisone in a stabilized carbamide drug delivery system effectively controls atopic eczema without the hazards of potent fluorinated corticosteroids. Clinical evaluation confirms that it is at least as effective as 0·1% betamethasone 17-valerate. The preparation has the physical properties of both a cream and an ointment and can be used in place of either. It has a high level of patient acceptance and can be used in fissured eczemas without causing any sensations of stinging or smarting.     

Light microscopic and ultrastructural distribution of type VI collagen in human liver: alterations in chronic biliary disease

We have investigated the distribution of type VI collagen in normal human liver obtained from cadaveric renal transplant donors, using a peroxidase-antiperoxidase method for light microscopic visualization, and an immunogold labelling method for ultrastructural localization. The distribution was compared with that of the more abundant interstitial collagen type III, using antibodies to amino terminal procollagen type III. Staining for type VI collagen was identified in Glisson's capsule, in portal tract stroma and within the space of Disse. Perisinusoidal staining showed intra-acinar heterogeneity with the intensity in acinar zones 2 and 3 being greater than in zone 1. Type III collagen was also found in the space of Disse although no significant intra-acinar variation in staining intensity was noted. Immuno-gold labelling for type VI collagen was demonstrated on amorphous or microfilamentous material lying between, and occasionally appearing to interconnect, cross-striated collagen fibrils, whereas labelling for amino terminal procollagen type III was exclusively on fibrils. Intracellular staining for type VI collagen was noted in perisinusoidal (lto) cells. These results confirm that type VI collagen is a ubiquitous constituent of the normal hepatic extracellular matrix and suggest that it may be synthesized by perisinusoidal (lto) cells. The distribution of type VI collagen was also studied in biopsy material from patients with different histological stages of primary biliary cirrhosis. Intense staining was noted around proliferating bile ductules within developing fibrous septa and in established septa of cirrhotic liver. These observations indicate that this 'minor' matrix component may play an important role in hepatic fibrogenesis.     

A two year controlled trial examining the effectiveness of ursodeoxycholic acid in primary biliary cirrhosis

Abstract Forty-six patients with primary biliary cirrhosis from a single centre were studied in a randomized placebo-controlled trial to determine the effectiveness of ursodeoxycholic acid (UDCA) over a 2 year period. The two groups were well-matched at baseline. For each parameter, by calculating the difference between the median changes with time between the UDCA group and the placebo group, it was found that from entry, with respect to placebo, there were differences between median changes (MCD) favouring the UDCA group in bilirubin {MCD 5 μmol/L [95% confidence interval (CI) 1 to 12] at 1 year and 5 μmol/L (95% CI 1 to 9) at 2 years}, alkaline phosphatase MCD 242 iu/L (95% CI 107 to 360) at 1 year and 268 iu/L (95% CI 146 to 424) at 2 years and aspartate aminotransferase MCD 26 iu/L (95% CI 12 to 41) at 1 year and 37 iu/L (95% CI 16 to 64) at 2 years. Within the UDCA group, there was long-term fall in alkaline phosphatase [median fall 116 iu/L (95% CI 93 to 378) at 2 years and aspartate aminotransferase [median fall 18 iu/L (95% CI 6 to 47) at 2 years; however, the major change in bilirubin was a modest rise over 2 years in the placebo group [median rise 2 μmol/L (95% CI 1 to 9)]. Changes in albumin, prothrombin ratio and immunoglobulins were generally minor and not significant.
Ursodeoxycholic acid did not generally influence stage progression or histological features, although a smaller percentage of non-cirrhotic patients were documented as having developed cirrhosis on UDCA compared to placebo (14 vs 57%) over the 2 years. There appeared to be no consistent effect on pruritus and general well-being. The medication was well-tolerated and safe. In conclusion, UDCA appears to have beneficial effects on some serum biochemical markers in primary biliary cirrhosis and so may have a role in retarding disease progression. It could be useful in combination with an immunosuppressive or an anti-fibrotic agent.