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Biomedical subjects

H Hettwer

Publications and source records attributed to H Hettwer.

At least 19 recordsLinked to original sources
PubMed1999

[PTLA (percutaneous transluminal laser angioplasty) recanalization of femoral artery stenoses/occlusions after Angio-Seal administration].

PURPOSE: To demonstrate desobliration of Angio-Seal-induced femoral artery stenosis and occlusion by Excimer-laser assisted angioplasty and PTA. PATIENTS AND METHODS: The Angio-Seal hemostatic closure device was applied to the puncture site in 1500 patients after diagnostic or therapeutic coronary artery catheterisation. In 5 of 1500 cases symptoms of claudication occurred. Following the determination of the walking distance and ankle-brachial systolic pressure index (ABI) and diagnostic angiography, therapeutic percutaneous transluminal laser angioplasty (PTLA) and PTA was performed. RESULTS: 5 patients with acute symptoms of peripheral artery disease presented with superficial femoral artery occlusions (three cases) and high grade stenoses of the common femoral arteries (two cases). Angiographic and clinical improvement was achieved after PTLA/PTA in all five patients. The mean walking distance increased from 61 meters to 600 meters. The average ankle-brachial systolic pressure index increased from 0.40 to 0.82. CONCLUSIONS: PTLA/PTA is a satisfactory therapeutic method for femoral artery occlusion or high-grade stenosis following Angio-Seal application.

Aged↗
PubMed1999

[Results of "cross-over implantation of Palmaz-stents" with cross-over sheaths].

PURPOSE: Presentation of technique of cross-over stent implantation of Palmaz stents using a cross-over sheath. MATERIAL AND METHODS: Between 1996 and March 1997 72 patients presenting symptoms of peripheral artery disease received 136 Palmaz stents, which were implanted in a cross-over technique with the aid of a cross-over sheath. RESULTS: As indications for stent implantation occurred: occlusion (n = 14), recoil (n = 11), distinctive calcification (n = 32), recurring stenosis/occlusion (n = 32), perforation (n = 3), dissection (n = 31), and aneurysms (n = 2). The cross-over technique with the aid of a cross-over sheath was successful in all 136 cases. Within the first 24 hours 3 acute reocclusions occurred (all femoral). For stents placed in the iliac artery the primary patency rate was 93.3% at 12 months and for stents placed in the femoral artery 72.0%. Furthermore, this techniques allows for simultaneous stenting of pelvic, femoral or lower leg arteries (n = 17). By using this technique, stenting of the distal external iliacal artery, common femoral artery (CFA) and proximal superficial femoral artery becomes either possible for the first time or easier. CONCLUSION: If Palmaz stents with a length of 2-7.8 cm should be implanted in the cross-over technique, the use of a cross-over sheath is recommended.

Aged↗
PubMed1994

Recurrent cervical lymphadenopathy: differential diagnosis with color-duplex sonography.

In this prospective study 45 patients with cervical lymphadenopathy treated by operation, radiation and/or chemotherapy were examined by color-duplex sonography. The aim was to investigate the lymph node perfusion and to find out whether differentiation between benign and malignant nodal disease after therapy was possible by resistance and pulsatility indices. In 200 of 245 lymph nodes (82%) color-duplex sonography was able to detect perfusion. Using a pulsatility index (PI) threshold of 1.6 and resistance index (RI) threshold of 0.8, differentiation between reactive nodal enlargement and metastases was possible with an accuracy of 96%. Differentiation between lymphomas and metastases by RI and PI was not possible. Qualitative assessment of perfusional patterns was useful in detecting malignancy because reactively enlarged nodes showed greater hilar perfusion whereas metastases showed an increased peripheral perfusion. Lymphomas had both increased central and peripheral perfusions.

Adipose Tissue↗
PubMed1993

[Health education in developing countries--Indian health promoters in a tuberculosis prevention program in the Chaco region of Paraguay].

Several characteristics obstacles exist in developing countries in respect of implementation or realisation of health programmes. The following article, however, shows how effective preventive health and health care measures can be made possible even in the face of seemingly insurmountable difficulties. The only presently existing model basing on many years of experience, consequent development and documented success in the targeted prophylaxis of tuberculosis, is that of the Latin American Indian health promoters in the Chaco of Paraguay. The article discusses the results of the authors' own investigations regarding the training curriculum for the job of a "health promoter", delegation and distribution of tasks and success of the programme (incidence of tuberculosis and death rates). These are discussed in respect of general consequences for a concept of health training in developing countries.

Cause of Death↗
PubMed1990

[Differentiation of human sperm cells using flow cytometry].

An improved method for differential staining and high-resolution flow cytometric measurement of human sperm cells is presented. Involving a mild pretreatment with citric acid/detergent and staining with DAPI, the new procedure provides excellent preservation and good discrimination of all cells present in normal and pathologic semen samples.

Flow Cytometry↗
PubMed1990

Flow cytometric discrimination of human semen cells.

An improved method for differential staining and high resolution flow cytometric measurement of human semen cells is presented. Using a mild pretreatment with citric acid/detergent and staining with DAPI, the new procedure provides excellent preservation and good discrimination of all cells which are present in normal and pathological semen samples.

Flow Cytometry↗
PubMed1987

Size dependent enzyme activities of multinucleated (osteoclastic) giant cells in bone tumors.

In osteoclastic giant cells of six different tumors of bones and joints (fibrous dysplasia, proliferating giant cell tumor, malignant giant cell tumor, osteosarcoma after chemotherapy, malignant synovioma and Ewing's sarcoma) activities of tartrate-resistant acid phosphatase, NADH-tetrazolium-oxidoreductase and, in three of them, of non-specific esterase are determined by enzyme histochemical methods. Quantitative microphotometry makes it possible to determine relative enzyme activities in the cut sections of giant cells of different sizes. Giant cells of the various tumors reveal similar trends: With an increase in cell size, mean extinctions of NADH-tetrazolium-oxidoreductase and non-specific esterase decrease. Mean extinctions of tartrate-resistant acid phosphatase increase in cells of medium size, whereas the large cells reveal in part low activities. An additional ultrastructural examination of the giant cells in the proliferating giant cell tumor as well as in the osteosarcoma shows morphological signs of degeneration in the large cells. Electron probe microanalysis of the proliferating giant cell tumor exhibits evidence of phagocytosis of Ca and/or Fe containing particles. The similar size dependent reaction pattern of enzymes in osteoclastic giant cells of different tumors favors the concept of a common histogenesis, i.e. a host reaction.

Acid Phosphatase↗
PubMed1986

Electron microscopic evidence for deep invaginations of the lamina propria towards the seminiferous tubule lumen in a patient with varicocele.

Ultrastructural studies on biopsy tissue from the right testis of a 39-year old patient with varicocele revealed 2.5-5 microns thick invaginations of the lamina propria towards the lumen of the seminiferous tubules. These invaginations were of various lengths. The presence of invaginations was confirmed through examination of serial semi-thin sections. In some seminiferous tubules two neighbouring deep invaginations were joined together thus completely encircling and thereby separating the basal compartment, and in some cases even the adluminal compartment, of the seminiferous tubule. The invaginations were surrounded continuously by the basement membrane and contained collagen fibres, cell processes of myoid cells and in some cases also their nuclei.

Adult↗
PubMed1985

The embryotoxicity of cyclophosphamide in rabbits during the histiotrophic phase of nutrition.

After iv injection of cyclophosphamide (CP; 80 mg/kg) and dechlor-CP (60 mg/kg) on the 9th day of gestation (histiotrophic phase of nutrition) in rabbits, the concentrations of activated CP and activated dechlor-CP were determined fluorometrically in the maternal blood and in the yolk sac fluid. Activated CP and dechlor-CP could be measured in the maternal blood but not in the yolk sac fluid. This holds true for both the free as well as the protein bound form. During the histiotrophic phase of nutrition on the 9th day of gestation, the yolk sac wall seems to be a barrier for activated CP and dechlor-CP. This phenomenon has to be traced back on the oxazaphosphorinring activated in position C4 and not on the alkylating activity. Therefore, a direct effect of activated CP can be excluded as the main reason for the embryotoxicity of CP. Consequently, the effects of iv-injected CP on the entoderm of the visceral layer of the yolk sac placenta were investigated. Three, 6, 12, and 24 hours after CP injection, the maternal animals were laparotomized and the entoderm of the visceral layer of the yolk sac placenta in the mesometral parts of the blastoderms were prepared for electron microscopy. Like in the control group, 3 hours after CP injection no differences are found. Six hours after CP injection, a relatively flat cell-type can be observed, which is probably based on the reduced absorptive capability of the entoderm. Twelve hours after CP injection the entoderm cells are nearly uniformly of the columnar type; this is interpreted as a restored absorptive activity. Twenty-four hours after CP injection the columnar form of the entoderm cells and the reduced pinocytotic activity are interpreted as a state of secretion. During the histiotrophic phase of nutrition (9th day of gestation in rabbits), CP-induced inhibition of the absorptive activity of the entoderm cells might lead to a quantitatively and/or qualitatively changed nutrition of the developing embryo. This changed nutrition may be the source of the embryotoxic effects of CP.

Animals↗
PubMed1985

Mg2+-ATPase activity in the rat testis and its correlation with the stages of spermatogenesis: a histochemical study.

The activity of Mg2+-activated ATPase was studied in the rat testis employing histochemical and microphotometrical methods. The enzymatic activity could be correlated with the stages of spermatogenesis. From stage XII onwards, the elongated spermatids showed a weak to moderate activity, which increased from the acrosomal phase to the maturation phase. The reaction product was located in the mid-piece and tail piece of elongated spermatids with a maximum intensity at stage VIII. Morphometric analysis revealed six distinct patterns, which could be correlated with the stages of spermatogenesis.

2,4-Dinitrophenol↗
PubMed1985

Microphotometric quantitation of enzyme activities in giant cell tumor of bone. A case study.

In a proliferating giant cell tumor of bone the activities of tartrate-resistant acid phosphatase (acPase) and of NADH-tetrazolium reductase were demonstrated by enzyme histochemical methods. Quantitative microphotometry made it possible to determine the relative enzyme activities per given volume unit in the cytoplasm of giant cells of several sizes. The activity of tartrate-resistant acid phosphatase increases with increasing cell size, whereas the activity of tetrazolium reductase will decrease in proportion. This coincidence of high acPase activity and low tetrazolium reductase activity in larger giant cells is interpreted as an expression of degenerative change.

Acid Phosphatase↗
PubMed1984

[The effect of organophosphates on heart ATPase in the rat].

The effect of organophosphate intoxication with diisopropylfluorophosphate (DFP), paraoxon and parathion on the activity of some ATPases of rat hearts was examined. Biochemical and histochemical methods were employed to determine the activities of the transport ATPase, of the myofibres and mitochondrial ATPases using different doses and antidote application. The organophosphates studied here had an inhibitory effect on the activities of enzymes. Biochemical measurements showed that the ATPase activities are dependent upon the duration of poisoning, the dose of poison and the applied organophosphates. DFP caused the highest restriction in activity of the examined ATPases. The Ca2+-stimulated ATPase was more sensitive than the Na+/K+-ATPase to the application of organophosphates. The antidote therapy determined the grade of influence on activity. Combined treatments of organophosphate poisoning with atropine and obidoxime chloride in the high doses of 7.5 mg/kg and 12.5 mg/kg body weight i.m. proved to be the most effective against the organophosphate intoxication. Antidote combination of small doses and also single application of atropine or obidoxime chloride might cause a stimulation of activity of the Na+/K+-ATPase and a significant decline of the Ca2+-ATPase.

Adenosine Triphosphatases↗