Incubation of lysozyme with acetaldehyde (0.44 M) at room temperature for 2 h produces a 62% inhibition of enzymic activity. Because the active site cleft contains tryptophyls, asparagine, glutamine, and an arginine residue, and because acetaldehyde reacts with indoles, amides, and guanidines, it is suggested that these sites are likely ones for alkylation. The epsilon-amino groups of lysines on the surface of the molecule are also susceptible to covalent modification. Total acetylation of lysozyme has been reported to inactivate the enzyme. These results suggest the possibility that inactivation of a fraction of the lysozyme activity by acetaldehyde may decrease the effectiveness of the enzyme in chronic alcoholics, thereby leading to an increased potential for susceptibility to bacterial infection.

Acetaldehyde↗

PubMedDate not supplied

A low-cost colorimeter.

A need for a colorimeter with low capital and maintenance costs has been suggested for countries with foreign exchange problems and no local medical instrumentation industry. This paper puts forward a design for such a device based on a domestic light-bulb, photographic filters and photovoltaic cells. The principle of the design is the use of a balancing technique involving twin light paths for test solution and reference solution and an electronic bridge circuit. It is shown that proper selection of the components will allow the cost objectives to be met and also provide acceptable linearity, precision, accuracy and repeatability.

Colorimetry↗

PubMedDate not supplied

The benefits of in-house cleaning.

Explore the source record for details and available documents.

Contract Services↗

PubMedDate not supplied

Additional extrarenal abnormalities seen in Tc-99m DTPA renal flow study.

During 99mTc-DTPA renal flow studies, extrarenal abnormalities have been found to include aortic abnormalities (aneurysm, ectasia, thrombosis, and abruptly decreased flow), splenic abnormalities (enlarged, small, or absent spleen), hepatic arterialization, and very slow circulation. In addition to the above abnormal findings, we add three more extrarenal pathologies that may be concomitantly found with renal flow study: pleural effusion(s), malignancy of the abdomen, and anemia and/or skeletal metastases.

Abdominal Neoplasms↗