Biomedical subjects
Publications and source records attributed to H Hofmann.
Survey of the clinical and diagnostic treatment of arteriomesenteric obstruction. Report on 4 cases of chronic obstruction and 2 cases of acute occlusion of the duodenum due to the root of mesenteric vessels. Indication of operation. Recommendation of retrocolic side-to-side duodenojejunostomy.
Purified hyaluronic acid of ox vitreous humour was isolated treating the acetone precipitate of a vitreous humour homogenate with 1 M NaCl solution and thereafter with cetylpyridiniumchloride. Both disc-electrophoresis and hydroxyproline content proved the absence of collagen in the purified hyaluronic acid. FeSO4, ascorbate, and cysteine changed the hyaluronic acid molecule and lowered the viscosity of the hyaluronic acid solution, EDTA alone did not affect the viscosity but enhanced the effectiveness of iron ions or ascorbate on the viscosity of the solution. Catalase prevented the reduction of the viscosity by the above mentioned substances. Therefore, it is suggested that H2O2 and free radicals are generated during the reaction. The free radicals produced are responsible for the change of the hyaluronic acid molecule.
Vitreous body fibrils and zonula fibers are analyzed by disc-electrophoresis. In both tissues the presence of collagen is established. The disc-electrophoresis patterns of vitreous body fibrils and zonula fibers show that a different type of collagen is present in each tissue. The absence of the alpha 2-chain indicates that the tissues investigated contain no type I collagen but types consisting of three identical alpha-chains.
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In a field trial a new influenza subunit vaccine was tested in parallel with a vaccine prepared from the whole virus. The subunit vaccine essentially contained only the proteins of the viral envelope, haemagglutinin and neuraminidase, which had been selectively solubilized by treatment with cetyl trimethylammonium bromide. Both vaccines contained 700 IU of strain A/Port Chalmers/73 in 0.5 ml. They were given to volunteers by the subcutaneous route with and without the addition of Al (OH)3 as adjuvant. Blood samples were taken on days 0, 28 and 90. Development of antibodies was assayed in the haemagglutination-inhibition (HI) and neuraminidase-inhibition (NI) test. All vaccines exhibited a very good immunogenic effect as judged from the number of volunteers with at least a four-fold rise in antibodies in the HI-test and those reaching titres that are considered to be sufficiently high for protection against disease. The best results were obtained with the aqueous subunit vaccine. All four vaccines also stimulated the formation of neuraminidase-inhibiting antibodies. The vaccines were well tolerated by the volunteers. The incidence of minor local reactions such as redness, swelling and pain varied according to the vaccine used, as shown on statistical evaluation. The aqueous subunit vaccine clearly proved to be superior in this respect.
401 cases of viral pneumonia diagnosed between January 1973 and August 1975 were investigated serologically by the complement-fixation test. The percentage distribution of the responsible pathogenic organism in this series of cases was as follows: influenza virus A 45.9%, Mycoplasma pneumoniae 19.5%, Coxsackie B viruses 9.2%, cytomegalovirus 7.5% and Chlamydia psittaci 8.5%. The remaining 9.4% cases were caused by adeno, parainfluenza, measles, influenza B, herpes simplex and respiratory syncytial viruses. Influenza virus was found mainly in elderly people (mean age 58.4 years), whilst pneumonia due to Mycoplasma occurred mainly in young adults (mean age 24.4 years). Infections with Coxsackie B viruses were almost entirely restriced to the warmer months; by contrast, the influenza virus was usually found in epidemic form and only during a few weeks in winter.
Some proteases, i.e. trypsin, alpha-chymotrypsin, thermolysin, proteinase K, alpha-amylase, collagenase, and papain were investigated on their effect on isolated zonular fibers. All these enzymes but collagenase were zonulolytic active. An attack on the ground substance of the fibers by substances solving glycosaminoglycans and proteoglycans (hyaluronidase, EDTA, guanidinium chloride, H2O2) showed an increased effect of the enzymes used. These results suggest that the interfibrillar matrix has a protective function on the zonular fibers.
Between December 1973 and October 1974 scrapings of the corneal epithelium of 52 patients were examined by immunofluorescence. 41 of these corneal scrapings were suitable for examination. In 31 of 38 cases with the clinical diagnosis of a herpes simplex keratitis virus-specific antigen was found by means of immunofluorescence. The procedure takes only a few hours, and shows with 81,5% correct diagnoses a high reliability; scrapings of patients without herpetic affection never revealed a positive result. In 3 of 4 cases of deep herpetic keratitis, in which the herpetic etiology could only be supposed clinically, the diagnosis was proved by immunofluorescence.
Electron microscopic studies proved, that in cases of macular corneal dystrophy (Groenouw II) abnormal deposits of acid mucopolysaccharide are demonstrable in the different layers of the cornea in a polymorphic form. Because of the investigations now performed it can be established, that the opacities of the paracentral, deep corneal layers result from both dispersed vesicular and plaque-like deposits of storage material in the border area of the stroma and Descemet's membrane.
By quantitative determination of antiproteinases, i.e. alpha1-antitrypsin, alpha1-antichymotrypsin, and inter-alpha-trypsin inhibitor normal values could be obtained. The importance of antiproteinases is demonstrated in this paper. Especially alpha1-antitrypsin was very easy to quantitate and might be of diagnostic interest.
Both vitreous body homogenate and a fibrous product containing hyaluronic acid and collagen isolated from vitreous humor by acetone precipitation were investigated to elucidate the liquefaction of vitreous body by acids. Graphic evaluation of the titration with hydrochlorid acid and viscosity measurements suggest a changed of the hyaluronic acid molecule in the pH-range between 5.2 and 4.1. Between these pH-values the ionization of carboxyl groups is decreased accompanied by conformational changes of the hyaluronic acid molecule. These results are in agreement with the conclusion of other authors that by lowering the pH of hyaluronic acid solutions a random coil to double helix transition of hyaluronic acid occurs.
The reactogenicity and immunogenicity of a new influenza subunit vaccine essentially containing only haemagglutinin and neuraminidase was studied in man. The vaccine was compared to commercially available vaccines, an adjuvant containing tween-ether split vaccine (800 IU per dose), and a fluid whole-virus vaccine (2100 IU per dose). Two dosages (700 and 2100 IU) of the fluid subunit vaccine were compared. All vaccines contained the virus strains recommended by the WHO for the 1975/76 season. In a double-blind study 399 volunteers were randomly selected to receive one of the four vaccines. The volunteers were examined for side-effects 24 and 48 hr after vaccination. Antibodies inhibiting haemagglutination were determined prior to and four weeks after vaccination. The sudunit vaccine at 700 IU per dose caused significantly fewer local side effects than the comparable split vaccine, and resulted in significantly higher antibody titers against both influenza A strains. A comparison of the subunit and whole virus vaccines containing high dosages (2100 IU) showed striking differences in reactogenicity. Subunit vaccine was very well tolerated. whereas whole virus vaccine caused systemic reactions, including fever and headache, in 15% of the volunteers. No significant reactogenicity was seen with a high dosage of subunit vaccine (2100 IU) although this is a three-fold increase on the currently used European dosage. Antibody titers were significantly enhanced however.
As an index of skin barrier function, transepidermal water loss (TEW) was investigated in subjects reactive to adhesive tapes. Tape reactive subjects showed no difference in TEW in untreated skin when compared to non-reactive subjects. Plastic tape and transparent tape produced varying degrees of dermatitis in reactive subjects; the TEW was increased up to 40-fold of the baseline values correlating with the degree of dermatitis. Paper tape and plastic film without adhesive did not produce dermatitis and increased water loss. Regeneration of skin damage was accompanied by a decrease of TEW values. The general problem of tape reactors and tape irritation is discussed.
Guinea pig, rat and sheep erythrocytes were sized electrically using the hydrodynamic focusing technique. The experimental curves were approximated with a computer by linear and logarithmic normal distributions. Rat and guinea pig erythrocytes from adult animals were best approximated by one linear normal distribution. Two populations (I, II) of erythrocytes with different mean volume could be demonstrated in young guinea pigs by this analysis. Population I erythrocytes are small, have a lower electrophoretic mobility and are mainly present at birth. They are gradually replaced by the larger population II erythrocytes. Both types of erythrocytes are probably the result of separate differentiation pathways. The analysis of erythrocyte volume distribution curves during immune lysis by antibody and complement shows that intact and ghost erythrocytes are measured by electrical sizing. No volume changes were observed up to the EAC1-8 intermediate. After the addition of C9, a C9 dose-dependent part of the erythrocytes swell permanently to spheroids. The spheroid transformation is a temperature-dependent, all or nothing reaction which is independent of protein osmotic forces from the interior of the cell.
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The vaccine used contained formalin-inactivated TBE virus that was grown in chick embryo cells and adsorbed to Alhydrogel. In a first study, conducted in 1973, a total of 81 volunteers were given subcutaneously two doses of vaccine 4 weeks apart, and a third dose 7-9 months later. After each vaccination, the rates of seroconversion were assayed in the hemagglutination inhibition test. The values obtained were 76%, 96% and 98%, respectively. The geometric mean titers found were 1:26, 1:36 and 1:44. The vaccine was well tolerated locally and systematic reactions such as fever headache and fatigue were only recorded after the first dose of vaccine. In 1974 and 1975 a total of 30,000 persons were vaccinated in areas where the disease is endemic. Most of the vaccinees work in forests and are, therefore, at high risk of infection. Circumstantial evidence indicates that the vaccine is protective.
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Enteroviruses were isolated from 27 patients during 1973 and 1974, 21 of these were Coxsackie B, 4 were ECHO and 2 were polio viruses, 5 further viruses could not be identified. Sera from 14 of the Coxsackie patients were investigated twice by means of the Complement Fixation Test (CFT). 11 of them showed a significant rise in antibody titre against one of the 6 different Coxsackie B viruses. No strong correlation was established between the result of the CFT and the isolated type of virus. Nevertheless, the CFT can be helpful in the diagnosis of a Coxsackie B infection. About 200 such cases with varied clinical features were diagnosed in the Department of Virology, Vienna University over the past 3 years by means of the CFT.