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Biomedical subjects

B Falck

Publications and source records attributed to B Falck.

At least 109 records · Page 6Linked to original sources
PubMed1979

Studies of the effect of peroral fenylpropanolamin on the functional size of the human maxillary ostium.

The effect of peroral fenylpropanolamin on the functional size of the human maxillary ostium was studied in 20 patients suffering from acute rhino-sinusitis. The size of the maxillary ostium was measured by a manometric procedure over a 2-hour period. During the introduction of a known airflow into the sinus for a short while, the pressure increase was compared with a nomogram obtained by model experiments. The introduction of the cannulas into the maxillary sinus caused a swelling of the mucosa in the ostium in the placebo group and initially also in the group receiving fenylpropanolamin, but, after 60 minutes, the latter group had a mean functional ostial size greater than the initial one. These differences were not statistically significant. This seems to be the first objective study of the size of the ostia in the human paranasal sinuses during treatment with a peroral decongestant.

Acute Disease↗
PubMed1979

Studies of the gas exchange and pressure in the maxillary sinuses in normal and infected humans.

The total gas pressure in experimentally occluded maxillary sinus was continuously recorded during 90 minutes on 7 healthy human subjects. PO2 and PCO2 were measured before and after the total pressure recording. In 3 cases the volume changes in the sinus were measured. The total gas pressure after an initial increase to about 35 mm H2O decreased to a steady state of about 70 mm H2O below atmospheric pressure. The volume changes in sinus showed a corresponding alteration. The gas measurements showed a decrease of PO2 of 25 mm Hg and a rise of PCO2 of 21 mm Hg. In 3 patients with acute purulent sinusitis there was seen a pressure of about 10 cm H2O above the atmospheric pressure.

Adult↗
PubMed1978

Organization of the sympathetic innervation in liver tissue from monkey and man.

The sympathetic innervation of the liver of monkey and man has been investigated in a combined fluorescence histochemical, chemical and electron microscopical study. By means of the Falck-Hillarp fluorescence method a dense network of monoamine-containing nerve fibers was visualized in liver tissue of monkey and man. The nerve fibers ran in close contact to both hepatocytes and blood vessels. Chemical quantitations showed high concentrations of noradrenaline in both human and monkey liver. Microspectrofluorometry of the intraneuronal monoamine resulted in spectra characteristic of a catecholamine. For the electron microscopical study the dopamine analogue, 5-hydroxydopamine, was used to "label" the catecholamine terminals in both human and monkey liver. The nerve profiles, identified as catecholamine-containing, were demonstrated in a perivascular location and in close contact to hepatocytes. No synaptic membrane specializations were present between nerve fibers and hepatocytes. The general ultramorphology and intralobular distribution pattern of nerves in the liver of monkey and man were similar. The present results prove the existence of a sympathetic innervation of hepatocytes and blood vessels in the liver of man and monkey.

Animals↗
PubMed1978

In vitro uptake of L-dopa and catecholamines into the epidermal Langerhans cell.

The Langerhans cells are capable of taking up L-dopa and the catecholamines dopamine and noradrenaline when exposed to these substances in vitro. Within the cell L-dopa is found in the cytoplasm as well as in the nucleus, whereas the catecholamines are confined to cytoplasmic granules. The L-dopa uptake is most probably carrier-mediated and the hypothesis is brought forward that L-dopa enters the cell by exchange diffusion. At present little is known about the nature of the amine uptake mechanism.

Cell Nucleus↗
PubMed1977

Evidence for new catecholamines or related amino acids in some invertebrate sensory neurons.

In certain sensory neurons of many different invertebrate species, including the sea anemones. Metridium senile and Tealia felina and the crustacean Artemia salina, fluorophores are formed during the course of the fluorescent histochemical technique of Falck-Hillarp. The presumed catecholamine nature of the neuronal fluorogenic compound was investigated by microspectrofluorometry, and the spectral characteristics of the fluorescence in the taxonomically different species was found to be very similar (excitation maximum at 375 nm with a smaller peak or shoulder at 330 nm and sometimes a shoulder in the spectrum at 410 nm; emission maximum at 475 nm). The emission maximum coincides with that of the catecholamines and DOPA (475 nm). The excitation maximum (375 nm) directly after formaldehyde treatment, however- differs from that of the catecholamines and DOPA (410 nm), but is similar to the excitation maximum displayed by these catechol derivatives at acid pH. The spectral characteristics of the fluorophore in the sensory cells might therefore theoretically be explained by an acid pH in the cells. This means improbable, however, and it is suggested that the phenomenon is due to the presence of unknown catechol derivatives. Analyses of the pH-dependent spectral changes indicate that the presumed catechol derivative in Tealia felina is beta-hydroxylated, whereas that in Artemia salina is not.

Amino Acids↗
PubMed1977

Fluorescence histochemical demonstration of dopa thioethers by condensation with gaseous formaldehyde.

The usefulness of the formaldehyde (FA) and glyoxylic acid (GA) methods for the fluorescence histochemical demonstration of dopa thioethers has been tested using protein droplet models. Similar fluorescence intensities were recorded from these compounds after either FA or GA treatment. Cysteinyldopa gave a high fluorescence yield similar to that obtained from dopamine and dopa in the FA reaction, whereas gluatitodopa showed a lower, although clearly visible fluorescence. Since the FA method seemed to be the most useful one for demonstration of catechol thioethers, the FA-induced fluorophores of these compounds were further characterized by microspectrofluorometry. The spectral characteristics of the thioether fluorophores (excitation maxima at 420 nm and emission maxima at 480-485 nm) distinguish these substances from dopa and other compounds fluorogenic in the Falck-Hillarp method. Dopa thioethers are proposed to form fluorophores with FA in a manner analogous to that of the primary catecholamines i.e. via low-fluorescent tetrahydroisoquinolines, along two different pathways, to strongly fluorescent 3,4-dihydroisoquinolines and 2-methyl-dihydroisoquinolinium compounds. These dihydroisoquinolines are in a pH-dependent tautomeric equilbrium with their quinoidal forms as reflected by a characteristic spectral shift upon acidification. The results of this study provide the guide-lines for the characterization of fluorogenic compounds in pigment-forming cells.

Cysteinyldopa↗
PubMed1977

Conjugated catechol derivatives in a transplantable islet cell tumour of the golden hamster.

Two glucuronidated catechol have been identified in a transplantable islet cell tumour of the golden hamster, i.e. dopamine-4-O-glucuronide and 3-methoxytyramine-4-O-glucuronide. L-dopa is rapidly metabolized in the tumour to one or both of these glucuronides. Incubation of tumour homogenates in the presence of beta-glucuronidase shows that dopamine-4-O-glucuronide is present in the tumour in extremely high concentrations.

Adenoma, Islet Cell↗
PubMed1977

Metabolism of 5-S-cyteinyldopa by O-methylation.

5-S-cysteinyldopa is metabolized by O-methylation on incubation with a liver extract and S-adenosyl methionine. O-methylated 5-S-cysteinyldopa isolated from melanoma urines by ion exchange and paper chromatography was identified by gas chromatography-mass spectrometry and NMR.

Animals↗
PubMed1977

Intracellular distribution of dopa and 5-S-cysteinyldopa in Harding-Passey melanoma.

The concentrations of dopa and 5-S-cysteinyldopa were determined in the various cell fractions of Harding-Passey melanomas. Dopa was present in larger amounts than was 5-S-cysteinyldopa in all cell fractions, but the dopa/5-S-cysteinyldopa ratio was lower in the soluble fraction and in the small-granule fraction than in the large-granule fraction. The soluble fraction contained the greatest amount of catechols. These findings are compatible with high tyrosinase activity not only in the melanosomes but also in the small-granule and soluble fractions.

Animals↗
PubMed1977

5-S-cysteinyldopa in the urine of melanoma patients.

A newly discovered amino acid, 5-S-cysteinyldopa, present in the urine of healthy subjects is excreted in pathological amounts in many patients suffering from melanoma metastases. Increased excretion of 5-S-cysteinyldopa may be observed before metastases become clinically evident. Determination of 5-S-cysteinyldopa is superior to determination of dopa+dopamine in the diagnosis of melanoma metastases.

Adult↗