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Biomedical subjects

H Neumann

Publications and source records attributed to H Neumann.

At least 109 records · Page 6Linked to original sources
PubMed1975

The reaction of tris (hydroxymethyl) aminomethane with calf intestinal alkaline phosphatase.

The effect of tris (hydroxymethyl) aminomethane concentrations on the rate of calf intestinal alkaline phosphatase-catalyzed hydrolysis of p-nitrophenyl phosphate was studied, in the pH range 8-10, where no transphosphorylation reaction could be detected. Kinetic analysis of the results permitted description of the effect of Tris concentrations T on the rate of enzyme catalyzed hydrolysis (V) by the following equation: (see article). The rate-accelerating effect of Tris concentrations can be ascribed to two different mechanisms: At moderate Tris concentrations (0.01-0.20 M) the enzyme forms a reversible addition complex with a Tris molecule. This complex has an enhanced catalytic activity. We suggest that the binding of Tris to the enzyme could potentiate a second active site of the enzyme, due to its ionization effect upon an acidic group of the enzyme of pK = 8.9. The modest linear rate accelerating effect of Tris at high concentrations (0.20-0.60 M) could be ascribed to the change of the dielectric constant of the medium, the degree of solvation of the protein, or change in the tertiary structure of the enzyme.

Alkaline Phosphatase↗
PubMed1975

[The treatment of the "mobile" vocal cord carcinoma: cordectomy versus irradiation (author's transl)].

In the literature, cordectomy and irradiation each give an about 80% 5-year cure rate in cases of stage I carcinoma of the vocal cords. Between 1955 and 1969 49 patients were cordectomized and 71 patients were subjected to irradiation (5-year absence of recurrence in 75%) and 68.8% of cases respectively. 6 out of 9 criteria are in favour of cordectomy and only 3 in favour of radiotherapy in a comparison of both forms of treatment. In favour of cordectomy: 1. Direct examination of the tumour. 2. Immediate histological control during the operation. 3. Duration of treatment: 7 to 10 days (irradiation: 4 to 5 weeks). 4. Short healing period. Irradiation may entail chronic after effects. 5. Perichondritis: not observed after operation but may follow irradiation. 6. Treatment of tumour recurrence: After cordectomy: non-irradiated area and, if required, full radiation dose possible or operation in ordinary tissue. After irradiation: full radiation dose not possible, operation only in irradiated tissue. In favour or irradiation: 1. Medical contra-indications to surgery. 2. Tracheotomy: required prophylactically in case of cordectomy for 1 to 3 days, usually not necessary in case of irradiation. 3. Voice quality: Clearly better after irradiation than after operation. Irradiation is preferable in patients who have to use their voice very much. The problem should be thoroughly discussed with the patient. In general, cordectomy is the treatment of choice.

Electrocoagulation↗
PubMed1975

[Total laryngeal extirpation in tumour recurrence following chordectomy (author's transl)].

A review of 18 cases of laryngectomy on account of tumour recurrence following chordectomy revealed a high incidence of post-operative salivary fistulae. The tumour recurrence was extensive, as seen from the extirpated larynx specimen, in spite of regular laryngological check-up examinations. Tumour recurrence rends to be localized in the anterior commissure and sometimes infiltrates into the prelaryngeal area. The poor long-term prognosis is stressed.

Glottis↗
PubMed1975

Photoreactions of phosphorothioate and cysteamine-S-phosphate. Photosubstitution and photophosphoryl transfer.

The photoreactions of phosphorothioate and cysteamine-S-phosphate were investigated. On irradiation of phosphorothioate a marked change in absorption spectrum was observed. The product migrated in high voltage electrophoresis, with different mobility from that of phosphorothioate and its dimer, or inorganic orthophosphate. It contained phosphate and sulfur in a ratio of 2: 1, without reducing properties. Therefore it was suggested that the product is either pyrothiophosphate, or a cyclic compound, with similar composition. On irradiation of phosphorothioate in the presence of potential phosphoryl group acceptor, such as glucose or galactose, 25-40% of the phosphoryl group was transferred. The formation of glucose 6-phosphate, or galactose 6-phosphate was observed. The photolysis of cysteamine-S-phosphate gave cysteamine, inorganic orthophospate and taurine. Under the same conditions of irradiation, inorganic orthophosphate or aminoethanol-O-phosphate were found to be stable.

Cysteamine↗
PubMed1975

Preference for basic IgG in early syphilis.

By differential IgG measurements of sera of 27 patients with early infectious syphilis, it was found that infection with T. pallidium results in a preferential synthesis of IgG immunoglobulins characterized by high isoelectric points. The decrease in total IgG level observed after 6 weeks of treatment can to a large extent be accounted for by the decrease in basic IgG concentration. The relationship between the total and basic IgG levels and the number of T. pallidum present in the body during the three early stages of the disease studied is discussed.

Adult↗
PubMed1975

[Electrophysiological studies on the prognosis in idiopathic facial paralysis].

The literature on electrophysiological techniques used so far for the prognostication of idiopathic facial palsies contains reports on 31 patients with idiopathic facial palsy, in whom - after electric stimulation of the nervus facialis at the point where it exits from the foramen stylomastoideum - the amplitude of the compound muscle action potential of the M. orbicularis oris was measured. The extent of the SPA's decline was related to the progress of the disease. In those cases where the SPA declined by at least 75-100 per cent, the palsy regressed either in an unsatisfactory manner or not at all. However, where the decline amounted to at most 67 per cent a restitutio ad integrum took place or residual symptoms which do not disturb the patients were found. The prognosis can be made between the 5th and 10th day after the palsy has developed. If in cases of idiopathic palsy the diagnosis is made at an early date, this method is more reliable than any other technique.

Action Potentials↗
PubMed1974

Distinct alkaline phosphatase in serum of patients with lymphatic leukemia and infectious mononucleosis.

A distinct alkaline phosphatase (phosphatase N) was demonstrated in the serum of patients with acute lymphatic leukemia, chronic lymphatic leukemia, and infectious mononucleosis. This enzyme closely resembles that extracted from the thymus of mice with lymphoma or lymphatic leukemia, both in its electro-phoretic mobility and its substrate specificity. The phosphatase N activity was related to the clinical state of patients with lymphatic leukemia and disappeared with recovery from infectious mnononucleosis.

Adolescent↗