Search PubMed⌕ Search

Biomedical subjects

H Maier

Publications and source records attributed to H Maier.

At least 235 records · Page 13Linked to original sources
PubMed1990

Fluorescent location of human colonic tumour cells by means of an enzyme-inhibitor complex.

We studied the enzymic status of the tumour cell surface protease, guanidinobenzoatase (GB) in frozen sections of a human colonic tumour grown in nude mice and also in human colons. Active enzyme was demonstrated by the binding of a synthetic fluorescent probe for the active centre of guanidinobenzoatase (GB). It was observed that tissue derived inhibitors of GB blocked the binding of this fluorescent probe and that enzyme inhibitor complex formation could be controlled by lowering the pH of the medium with lactic acid. The presence of an inhibitor of GB in the mouse tumour extract was taken advantage of by making two fluorescent derivatives of this inhibitor; both of which located GB on colonic tumour cells in frozen sections of human colon.

Aminacrine↗
PubMed1990

[Facial paralysis in chronic nonspecific inflammation of the parotid].

Benign diseases of the parotid gland only rarely cause facial nerve paralysis. A parotid gland tumour with peripheral facial nerve paralysis is generally accepted as being malignant, although this rule is not without exceptions. We report a case of chronic non-specific parotitis with an inflammatory pseudotumour causing a peripheral paralysis of the ipsilateral facial nerve. Antiinflammatory and antibiotic treatment caused the complete remission of the parotitis and facial nerve palsy within 6 weeks.

Aged↗
PubMed1990

[Angioneurotic edema of the tongue, induced by administration of ACE inhibitors].

Inhibitors of angiotensin converting enzyme can rarely cause an angioneurotic edema of the upper airways. This complication depends on the interaction with hormones regulating the vascular resistance such as the kallikrein kinin and the prostaglandin systems. We present two cases of angioneurotic edema of the tongue induced by inhibitors of angiotensin converting enzyme. We describe the symptoms of this side effect and discuss possible therapeutic approaches.

Angioedema↗
PubMed1990

[(Chemo-) prevention of second tumors in patients with head and neck neoplasms].

This review discusses the possible role of chemoprevention in the improvement of survival rates and the prevention of secondary primary tumours in patients with head and neck cancer. Chemoprevention is a new treatment that is especially promising for high risk groups. The fear that the advantages of this treatment will be outweighed by the disadvantages of side-effects and toxicity has not been confirmed by current studies. Randomized studies are needed to show whether chemoprevention can reduce the frequency of second primary tumours.

Carotenoids↗
PubMed1990

[Occupation and cancer of the oral cavity, pharynx and larynx].

There is increasing evidence of an association between occupational factors and head and neck cancer. The present paper reviews the most relevant epidemiological studies published within the last 30 years. Generally these studies indicate an increased cancer risk for "blue collar workers" exposed to dust or inhaled organic and inorganic agents. Moreover, the increased risk of head and neck cancer in most studies persists after adjustment for alcohol and tobacco consumption. More detailed, clinically orientated studies are necessary to provide a better understanding of the role of occupational factors in head and neck cancer.

Carcinogens↗
PubMed1990

[Fine needle biopsy in diagnosis of cervical lymph node changes].

In this study the validity and specificity of fine needle aspiration biopsy in cervical lymph node disease was examined. From 1983 to 1989, 495 outpatients were subjected to fine needle aspiration biopsies. One hundred and seven of the smears were not usable due to insufficient material. Tumour cells were found in 124 of the remaining 388 smears. In 117 of these cases the cytological findings were confirmed by later histology or clinical history. In the 7 remaining cases the cytological diagnosis of malignant lymphoma was disproved by histology. There were 38 (14%) false-negative diagnoses in 264 smears without tumour cells. In most of these cases the patient had undergone prior surgical or radiation therapy or had a malignant lymphoma. In spite of this relatively high number of false-negative results fine needle aspiration biopsy is helpful in the diagnosis of cervical lymph node disease. It must be emphasized that it is a screening method only: in the diagnosis of a tumour the method can only confirm and never disprove the clinical suspicion of malignancy.

Biopsy, Needle↗
PubMed1989

Vacuolar myelopathy with multinucleated giant cells in the acquired immune deficiency syndrome (AIDS). Light and electron microscopic distribution of human immunodeficiency virus (HIV) antigens.

Vacuolar myelopathy (VM) is a frequent neurological complication of the acquired immune deficiency syndrome (AIDS). A suspected connection between VM and human immunodeficiency virus (HIV) has been based only on HIV isolation from affected spinal cord tissue. We report here an AIDS patient dying after 14 months of progressive dementia, including 3 months of spinal signs and symptoms. At autopsy, the brain revealed moderate diffuse damage of the white matter compatible with HIV-induced progressive diffuse leukoencephalopathy. The spinal cord showed VM mainly in the lateral and the posterior columns. Mono- and multinucleated macrophages were localized within intramyelinic and periaxonal vacuoles. Light and electron microscopic immunocytochemistry revealed the presence of HIV antigens restricted to mono- and multinucleated macrophages within the spongy lesions. Productive HIV infection is documented for the first time within VM lesions of this case. Therefore, VM should be included among HIV-induced lesions of the central nervous system. The intimate relation of infected macrophages to vacuolar myelinopathy could suggest secretion of a myelinotoxic factor by macrophages productively infected by HIV. Immune electron microscopy appears as promising tool to detect HIV in tissue even when the density of virus may be low.

AIDS Dementia Complex↗
PubMed1989

Activity of the proteolytic enzyme guanidinobenzoatase in human basal cell carcinoma.

Basal cell carcinomas exhibit a characteristic pattern of aggressive invasion from the basal layer of skin epithelial cells. These tumour cells possess an enzyme, guanidinobenzoatase (GB), which is known to be associated with cell migration. The enzyme is inhibited by a fluorescent probe, 9-aminoacridine, and this can be used to locate cells possessing active guanidinobenzoatase. All basal cell carcinoma cells in frozen sections were located by their ability to bind 9-aminoacridine. Extracts of most tissues were shown to contain inhibitors of the GB associated with basal cell carcinoma cells. Extracts of skin, however, failed to inhibit this tumour-associated GB. The significance of these results is discussed in terms of the pathophysiology of basal cell carcinomas.

Aminacrine↗
PubMed1989

Inhibition of a protease associated with tumour cells and the probable mechanism of regulation of this interaction in vivo.

The regulation of activity of a protease on the surface of human colonic tumour cells implanted in nude mice has been studied. A synthetic fluorescent probe was used to locate cells possessing active guanidinobenzoatase in frozen sections of tumour bearing tissues. These studies demonstrated the presence of intracellular protein inhibitors of guanidinobenzoatase which could be extracted in isotonic saline and transferred to the outer surface of the tumour cells. This study showed that the inhibition of guanidinobenzoatase was pH dependent and that the tumour cell may regulate the activity of its surface guanidinobenzoatase by exporting lactic acid.

Animals↗
PubMed1989

Inhibition of trypsin-like enzymes on cells with rhodamine-aprotinin.

Aprotinin, a polypeptide inhibitor of trypsin-like enzymes, has been labelled with rhodamine. Rhodamine-aprotinin inhibits trypsin in free solution in an identical manner to aprotinin. Rhodamine-aprotinin binds to trypsin-like enzymes on cells in formaldehyde fixed wax embedded sections. This technique has been used to locate cells possessing trypsin-like enzymes by means of fluorescent microscopy. In the present study we have used this technique to locate tumour cells.

Animals↗
PubMed1989

Coexpression of intermediate filaments in squamous cell carcinomas of upper aerodigestive tract before and after radiation and chemotherapy.

Frozen sections of 48 squamous cell carcinomas and seven undifferentiated carcinomas of the upper aerodigestive tract were investigated immunohistochemically with monoclonal antibodies specific for keratin, vimentin, desmin, neurofilaments, and glial fibrillary acidic proteins. In nine squamous cell carcinomas (19%) and six undifferentiated carcinomas (86%) obtained before treatment coexpression of keratin and vimentin was detected in some tumor cells by double immunofluorescence studies. Nine squamous cell carcinomas expressed neurofilaments in scattered tumor cells. Coexpression of vimentin or neurofilaments was seen especially in the peripheral cell layer of the tumor nests and did not seem to correlate with the degree of differentiation. Three undifferentiated carcinomas additionally expressed desmin, and one tumor contained neurofilaments. Glial fibrillary acidic proteins were not detected. Increased coexpression of keratin with vimentin, desmin, or neurofilaments was seen in some tumors that were studied before and after radiation/chemotherapy, suggesting that the intermediate filament profile of tumor cells can be altered by external influences.

Carcinoma, Squamous Cell↗
PubMed1989

Gyrase inhibitor ciprofloxacin in human parotid saliva.

The excretion of ciprofloxacin (Ciprobay) via the human parotid gland was investigated. 2 h after an intravenous bolus injection (200 mg ciprofloxacin) mean serum concentrations of 0.43 mg/l were achieved, and these decreased within 6 h after injection to 0.17 mg/l. The concentrations of the gyrase inhibitor in parotid saliva showed a close positive correlation to the serum levels (r = 0.96), but they were significantly lower than serum levels. They decreased from 0.1 mg/l 2 h after injection to 0.04 mg/l after 6 h.

Chromatography, High Pressure Liquid↗
PubMed1989

[Tonsillolith: clinical picture and mineralogic analysis].

We report the clinical appearance and mechanism of origin of a tonsillolith 7 g in weight, found in a 77-year-old patient and simulating a tumour of the oropharynx. Mineral analysis showed the main ingredients to be CaO and P2O5. Only trace amounts of SiO2, MgO, Na2O and K2O were found.

Aged↗