The effect of age on the pharmacokinetics of diazepam

1. After intravenous administration to 19 subjects, aged 18-95 years, plasma diazepam concentrations were measured over 160 h. Plasma protein binding of diazepam was also measured in each subject. 2. The terminal plasma half-life of diazepam ranged from 15.0 to 125 h and was positively correlated with age (r = 0.797). Total plasma diazepam clearance was not correlated with age (r = -0.017). 3. The free fraction of diazepam ranged from 0.0137 to 0.0386 and was significantly correlated with age (r = +0.863). Free diazepam clearance, which ranged from 432 to 1870 ml/min, was also correlated with age (r = -0.717). 4. It is concluded that the increased sensitivity of the elderly to diazepam is, at least in part, due to pharmacokinetic factors.

alpha1-Antitrypsin: the presence of excess mannose in the Z variant isolated from liver

The Z variant of alpha1-antitrypsin was isolated by a new technique from the liver of a patient homozygous for the Z allele of the protease inhibitor locus. The material was homogenous and antigenically competent but had no protease inhibiting capacity. An interesting correlation was found between the subcellular localization and the carbohydrate composition of the Z variant from liver. Carbohydate analysis of this glycoprotein showed an absence of galactose and sialic acid, an appreciable decrease in N-acetylglucosamine, and an almost twofold increase in mannose residues. These data indicate a considerable slowdown in the processing of the oligosaccharides of liver Z variant. In spite of the absence of sialyl residues, the liver Z varant was microheterogeneous by analytical isoelectric focusing. The isoproteins of liver Z variant coincided with those of asialo M variant in the focusing field.

Selective staining of alpha1-antitrypsin (alpha1-protease inhibitor) with Schiff's reagent after separation from serum by analytical isoelectrofocusing in polyacrylamide gel

After electrofocusing serum from human and various animals in the pH range 4.0-6.0, only the isoproteins of antitrypsin stain with Schiff's reagent. As an additional advantage, this staining provides information about the relative contents of the Schiff-positive carbohydrates of various antitrypsins.

Selective staining of alpha1-antitrypsin (alpha1-protease inhibitor) with Schiff's reagent after separation from serum by analytical isoelectrofocusing in polyacrylamide gel

After electrofocusing serum from human and various animals in the pH range 4.0-6.0, only the isoproteins of antitrypsin stain with Schiff's reagent. As an additional advantage, this staining provides information about the relative contents of the Schiff-positive carbohydrates of various antitrypsins.

The New South Wales mastitis control program. 2. Effect upon bacterial infections

Bacteriological examinations were made on quarter samples from cows in 35 herds over a 3 year period to monitor the response in a mastitis control program. Initially, Staphylococcus aureus predominated in 32 of the herds and the mean herd prevalence was 26%. The control measures halved this rate but there was considerable variation in response between herds. The decline occurred rapidly and there was a significant reduction (P less than 0.01) by 3 months. Streptococcus agalactiae predominated in 3 herds and the overall infection rate was 4.9%. Control measures eliminated the infection completely from most herds but reinfection occurred in 2 herds. The greatest decline occurred in the first 6 months and was significant (P less than 0.05). The measures had little effect upon Str. uberis and Str. dysgalactiae which remained fairly consistently at low levels. Initially, strains of Staph. aureus resistant to penicillin were dominant in most herds. In a minority of herds strains resistant to streptomycin predominated and in these herds there was a concurrent resistance to penicillin. These patterns did not change greatly over the control period. Resistance by Str. agalactiae to streptomycin occurred in most herds at the start of the program.

Partial preparative separation and properties of the isoinhibitors of human alpha 1-antitrypsin (alpha 1-protease inhibitor)

Human lapha 1-antitrypsin (alpha 1-protease inhibitor) was chromatographed on a DEAE-cellulose column at pH 6.4. After elution with a linearly increasing concentration of NaCl, five pools (pools I-V) were formed from the eluate, pool I corresponding to the lowest and pool V to the highest concentration of salt. As demonstrated by analytical isoelectric focusing, with increasing concentrations of NaCl the concentration of the cathodal isoinhibitors gradually decreased and the concentration of the anodal ones increased in the pools. Pool I contained only three cathodal and pool V only three anodal isoinhibitors with a limited overlap between the pools. In contrast with the isoinhibitor composition, the sialic acid contents of the pools did not vary with the elution conditions. In line with the chemical evidence, desialylation of the fractions did not affect their electrofocusing positions relative to one another and did not abolish the microheterogeneity of the protein.

The purification and properties of human alpha1-antitrypsin (alpha1-antiprotease), variant Z

After three stages of preliminary purification, variant Z was chromatographed on a DEAE-cellulose column. Upon elution with a linearly increasing concentration of NaCl, variant Z was recovered in two separate peaks, the first of which contained 81% and the second 19% of the total. The preparation corresponding to the first peak was homogeneous by various criteria. The trypsin and chymotrypsin inhibiting capacities and the specific antigenic activity of the preparation were nearly the same as those of an authentic sample of variant M. Variant Z contained 8 or 9 more gycine residues than variant M, but no appreciable difference was found between their carbohydrate contents. By analytical isoelectrofocusing the isoinhibitors of purified variant Z overlapped with those in the plasma of the donor and were cathodal to, but partially overlapped with purified variant M. After desialysation, the overlap between the different variants became complete, but variant Z contained a larger proportion of cathodal and smaller proportion of anodal components than variant M. Both variants formed five distinct isoinhibitor-protease complexes after incubation with trypsin and chymotrypsin and the corresponding complexes in the different variants completely coincided.

Drug-based prevention of pressure-sores

A double-blind clinical trial was carried out in 85 patients undergoing surgery to the upper shaft of the femur and to the hip-joint. In the control series, 27% developed pressure-sores before discharge from hospital. In the group in which 80 I.U. of corticotrophin (A.C.T.H.) in gelatin solvent was administered, only 12% developed pressure-sores. 19% of the patients with fractures to the upper shaft of the femur developed sores because accurate timing was not always possible. Prevention was complete in the case of total-hip replacement which is an elective procedure where A.C.T.H. can be administered at the right time to prevent disruptive damage to the microcirculation. It is suggested that the administration of A.C.T.H. should form part of the management of all high-risk surgical situations.

ACTH and decubitus ulceration: an experimental study

1. Ulcers due to neurectomy with excision of the sciatic nerve are more severe than those due to tenotomy and can be inhibited by a single dose of ACTH.2. Timing and mode of administration of ACTH to prevent decubitus ulceration is critical and depends on its ability to prevent the separation of endothelial cells.

Perception of the Mueller-Lyer illusion in normal and aphasic adults

12 aphasic and 12 normal adults were tested on an adjustable Mueller-Lyer Illusion and a comparison Line-match Test. While the aphasic Ss showed more illusory effect, there were no statistically significant differences between groups. The effects of starting position and side of presentation were significant. Some implications of these findings are discussed.