Evaporative water loss and epidermis regeneration in partial-thickness wounds dressed with a fluid-retaining versus a clot-inducing wound covering in guinea pigs

The effects of a new high vapour permeable poly-(ether urethane) (PEU) wound covering on evaporative water loss (EWL) and epidermis regeneration in partial-thickness wounds in guinea pigs were investigated and compared with an occlusive wound covering (OpSite) and air-exposed controls. It was also assessed whether the EWL reflected the phases of epidermis regeneration. In PEU-covered wounds, the initially raised EWL of 100 gm-2h-1 decreased in four days to 30 gm-2h-1, the same level as in occluded wounds. In control wounds this level was only reached after seven days, reflecting slower epidermis regeneration. The results showed that triphasic EWL behaviour corresponded to the sequence of wound healing. There was (1) a constant raised EWL until epidermal resurfacing is complete, (2) a fast EWL decrease during parakeratotic keratinization, and (3) a gradual normalization of the EWL during maturation of the stratum corneum. In wounds covered with OpSite this phasic EWL behaviour did not occur, owing to forced reduction because of the relatively impermeable covering. It was concluded that the PEU wound covering has an ideal water vapour permeance of 22.2 gm-2h-1 kPa-1, as can be seen in the accelerated epidermis regeneration and fast EWL reduction in partial thickness wounds in guinea pigs.     

Dorsal carpometacarpal dislocation of the index finger: a report of three cases and a review of the English-language literature.

Isolated dorsal carpometacarpal dislocation of the index finger is a rare injury. We treated three patients with such an injury; two cases by delayed open reduction and internal fixation, and one case by direct closed reduction and internal fixation. Satisfactory functional results were obtained in two of the three cases (follow-up of 4 and 2 years, respectively). Anatomic factors, the mechanisms of injury, and management as discussed in the English-language literature are reviewed.     

Flare up of joint inflammations induced by cloned helper T cells. Retention of the helper T cells

Joint inflammations were induced in mice by intra articular (ia) injection of cloned helper T cells specific for methylated bovine serum albumin (mBSA) together with mBSA. Local injection of mBSA several weeks after waning of a joint inflammation induced by cloned helper T cells caused a flare up reaction. This indicates that the helper T cells persisted in the joint after the primary inflammation. In the present paper we show that the helper T cells can also persist for some time in a knee joint in the absence of the specific antigen and/or an inflammatory reaction.     

Use of bispecific hybrid antibodies for the development of a homogeneous enzyme immunoassay

Hybrid bispecific monoclonal antibodies reacting with carcinoembryonal antigen (CEA) and with the E. coli enzyme beta-galactosidase (GZ) were produced by fusion of hybridomas or chemical linkage of half-antibodies. Since the original anti-GZ antibody used in these experiments was capable of protecting GZ from thermal denaturation, it was possible, by hybridizing it with two different non-competitive anti-CEA antibodies, to design a homogeneous enzyme immunoassay for quantitation of CEA. In fact, a mathematical analysis of the reaction indicates that, under appropriate concentrations of the reactants, circular complexes can be formed which contain the two hybrid antibodies, the GZ enzyme and the CEA antigen. The stability of these complexes can be expected to be substantially greater than that of the more labile CEA-free GZ-antibody complexes, prompting a significant increase in the amount of enzyme molecules which are bound to antibody and are consequently protected from thermal denaturation. These expectations were supported by experimental results: under appropriate conditions, heat-resistant enzyme activity was indeed proportional to concentration of CEA in the range up to 75 ng/ml. As predicted by theory, however, in the presence of excess CEA - in fact at CEA concentrations which are higher than those of possible clinical relevance - circular complexes tended to open up, leading to a marked prozone effect.     

The Characterization of the Silver Compounds of Some Sulfanilamide Derivatives

The structures of 1: 1 compounds of silver with twelve sulfanilamide derivatives are studied. In the compounds with sulfadimethoxine and sulfafenazole the silver ion is coordinated to the deprotonated amido nitrogen (amido-Ag structure). In the compounds with sulfadimidine, sulfamerazine, sulfamethoxazole, sulfamethoxydiazine, sulfamethoxypyrazine, sulfamethoxypyridazine, sulfamethylthiadiazole, sulfamoxol, sulfisomidine and sulfisoxazole the silver ion is coordinated to the nitrogen which is attached to the atom in the substituent (imido-Ag structure). In the compounds with sulfamerazine and sulfamethoxypyrazine the aromatic amine group is probably involved in coordination. The findings are discussed in relation to the results of a preliminary study on sulfadiazine silver. This silver compound is exceptional among the silver sulfanilamides because of its amido-Ag structure. There are indications that sulfadiazine silver has a high formation constant as compared with the other silver sulfanilamides.     

Clearance of alpha 1-antitrypsin isoelectric focusing patterns in blood samples treated with heparin.

Plasma samples, whose typing for alpha 1-AT is made difficult or impossible because of an excess of heparin used as anticoagulant, can be treated very effectively with protamine sulphate. The addition of this heparin antagonist results in complete clearance of the isoelectric focusing pattern.     

Ionic Silver Compounds of Sulfanilamide Derivatives and Related Substances

Coordination of Ag(I) with the anion of a sulfanilamide (L) usually produces a non-conducting compound of the composition AgL. However, with sulfamethoxypyrazine and sulfacetamide an ionic compound [AgL₂]Ag is formed. Model substances demonstrate that the presence of one suitable donor atom (the deprotonated acidic N) results in the formation of ionic compounds of type [AgL₂]Na and [AgL₂]Ag. The presence of an aromatic NH₂ group as the second donor group results in the formation of only one type, namely [AgL₂]Ag. The silver compounds were studied by the use of conductivity, UV and IR measurements.     

Superficial lightning injuries--their "fractal" shape and origin

The origin of superficial lightning burns was studied. A recently developed mathematical model was invoked to identify fern-shaped burns as 'so-called' fractals. On the basis of this model and discharge experiments, we conclude that 'fractal burns' are caused by surface discharges of a positive polarity. The recognition of such burns can help to elucidate the type and mechanism of the lightning strike.     

Serum immunoglobulinD in infants and children

Serum immunoglobulinD (IgD) concentration is usually low in healthy individuals as compared to other immunoglobulin classes. Most studies on serum IgD are concerned with serum levels in healthy adults but reference values for young children and infants are not easily available. In order to establish age specific reference values we measured IgD levels in serum of 184 healthy Icelandic children, age 0-14 years and 60 healthy blood donors age 18-63, using the ELISA technique. Special attention was paid to the youngest age groups. Results showed low IgD values in infants and young children, gradually increasing until the age of 10 but then decreasing with age. We conclude that IgD gradually increases with age in childhood as other immunoglobulin classes but later declines. These findings can be of importance in revealing the function of IgD in the immune system as well as in the diagnosis of the hyper-IgD syndrome.