Biomedical subjects

K Helmke

Publications and source records attributed to K Helmke.

At least 55 records · Page 3Linked to original sources

PubMed1993

[Child abuse--a surgical analysis].

Non-accidental injuries are frequently treated by surgeons without the real reason behind the trauma being identified: The differential diagnosis of child abuse would not be considered in this circumstance. This report gives hints as to the different aspects of this complex type of injury. With our case unusual (atypical) injury patterns have been shown and the diagnostic and therapeutic procedures with child abuse explained from a surgical point of view. It is of central importance to check, whether the trauma history according to the accompanying adults for the actual surgical type of injury is plausible. Incongruencies here must lead to search for further signs of trauma or its residues. When treating these children the surgeon is therefore in a key position especially to prevent future abuse, bearing in mind the special relevance of its striking high recidivation frequency.

Child↗

PubMed1993

[The use of imaging procedures in gastrointestinal diseases with space-occupying lesions in children].

Sonography is gaining in importance for examination of childhood illnesses of the gastrointestinal tract. Disadvantages of ultrasound result from the gaseous elements naturally contained in the intestine. Tumors of the digestive tract can be best classified on the basis of their relationship to the tract wall and their intra- or extraluminal location. The type of echogenicity can also aid diagnosis. A differentiation between infectious pseudotumors and neoplasms is thus often possible when sonographic images are considered in combination with clinical and laboratory data. The systematic use of ultrasound also allows more precise application of endoscopy and other imaging techniques.

Child↗

PubMed1992

Colour-coded echographic flow imaging and spectral analysis of cerebrospinal fluid (CSF). Part III. In-vitro study of low flow velocity detection related to decreasing particle concentration (hematocrit) and tube lumen.

An in-vitro steady flow system was designed to determine the lowest flow velocities that can be detected by echographic colour flow imaging and spectral analysis. The flow detection level was determined hydrostatically by reducing the fluid level to below the point at which a flow signal was visible, then increasing the height until the colour flow reappeared. This was confirmed in all instances by spectral analysis. The height (angle-corrected velocity) of the spectral envelope was also determined. Mean volume flow was then obtained by using a graduated cylinder and a stop watch. The lowest hematocrit detectable was identified using a stepwise dilution of packed human red blood cells with 0.9% sodium chloride. Three different PVC-tubes with inner diameters of 2.1 mm, 1.1 mm and 0.51 mm were used.(ABSTRACT TRUNCATED AT 250 WORDS)

Air↗

PubMed1992

Diagnosis and treatment control of choroidal melanomas--the role of B-scan and Doppler-technique.

B-scan guided pulsed Doppler ultrasonography was applied in 62 patients with unilateral malignant melanoma. Prior to radiotherapy Doppler frequency shifts were detected in all but one neoplasm. The average systolic tumour blood flow velocity was recorded as 18.8 +/- 7.6 cm/s. Frequency shifts after radiotherapy are described. Probably the methods will find a place in the evaluation of indeterminate fundus lesions and in the follow-up of irradiated ocular melanomas.

Blood Flow Velocity↗

PubMed1991

Doppler ultrasonography of the ophthalmic and central retinal vessels.

B-Scan-guided, pulsed Doppler ultrasonography of central retinal vessels and ophthalmic arteries of 72 normal subjects gave the following average peak flow velocities: central retinal artery, 9.5 +/- 3.1 cm/s; central retinal vein, 5.7 +/- 1.5 cm/s; and ophthalmic artery, 31.6 +/- 9.0 cm/s. Doppler shifts in the central retinal vessels were absent at intraocular pressures above 80 mm Hg. Ophthalmic artery systolic, middiastolic, and end-diastolic velocities significantly declined as a function of age. The technique is independent of the status of the ocular media, is noninvasive, requires little time, and causes minimal discomfort.

Adult↗

PubMed1991

Doppler ultrasonography of malignant melanomas of the uvea.

Doppler shifts were detected using duplex and color Doppler scanning in 41 of 42 patients with malignant melanomas of the uvea. Mean maximum tumor systolic velocity was 18.8 +/- 7.6 cm/s. Time-averaged maximum velocity in the tumor vessels was 12.3 +/- 5.3 cm/s. Maximum tumor velocity increased in four of eight tumors and was unchanged or had diminished in the other four 2 to 3 days after ruthenium plaque irradiation. Doppler shifts were undetectable in three tumors, markedly reduced in three tumors, and unchanged in one tumor 1 to 4 months after treatment. We detected minimal non-pulse-synchronized Doppler shifts in one of three tumors, and no shifts in the remaining two tumors 1 1/2 to 4 years after therapy. Color duplex scanning allowed a rapid overview of tumor vasculature and facilitated study of individual vessels.

Blood Flow Velocity↗

PubMed1991

[Therapy strategies for Still's syndrome of adults (AOSD)].

The differential diagnosis of seronegative polyarthritides are manyfold and can cause problems even for the routine rheumatologist. Together with the symptom "fever of unknown origin" an intensive diagnostic workup is often unavoidable. Five patients with this symptom combination are discussed who also had different typical manifestations of the adult onset Still's disease (AOSD).

Adolescent↗

PubMed1991

[Color-coded Doppler sonography of orbital blood vessels with special reference to the central retinal artery and vein].

When certain conditions are met, parameters correlating with orbital and retinal perfusion can be investigated non-invasively with the use of Doppler ultrasonography. Color coding allows more rapid vessel localization and more precise definition of sample volume localization. Flow direction and blood velocity in the central retinal artery and vein, as well as in the ophthalmic artery, were evaluated under normal and pathological conditions using current B-scan Doppler instruments with color coding. Fourteen patients with central artery occlusion, 9 with central vein occlusion, and 9 with orbital arteriovenous fistulas were compared with a control group. In the patients with retinal venous prethrombosis and thrombosis, the blood velocities were not significantly decreased. Patients with retinal arterial occlusion had contradictory findings, presumably since recanalization had already taken place. Echographic flow imaging might be most useful when, particularly after treatment, flow velocity patterns in the orbital vessels are evaluated, and when angiographic procedures can be avoided. Illustrative cases such as spontaneous dura-cavernous sinus fistulas versus cavernous sinus thrombosis show that difficult diagnostic decisions can be made easier.

Adult↗

PubMed1991

[Induction of autoreactive T-cells by bacterial stress proteins in HLA-DR4 donors].

From the peripheral blood of HLA-DR4+ healthy donors or patients with rheumatoid arthritis autoreactive T-cell lines were obtained after stimulation with bacterial heat-shock protein. All lines obtained express an alpha/beta-T-cell receptor and they are predominantly CD4+. The determination of the fine specificity of those autoreactive T cells showed, that either amino-acid position #71 or #86 of the HLA-DR beta 1 chain was critical for recognition by the antigen receptor.

Blood Donors↗

PubMed1991

[High dose 7S-immunoglobulin therapy in collagenoses. Clinical observations and effects on the lymphocyte subsets and immunoglobulin production].

Therapy with 7S-immunoglobulins in 8 patients with various connective tissue diseases led to a decrease of clinical disease activity. In vitro experiments showed that treatment induces change of B-cell function. Significant quantitative alteration of relative lymphocyte subpopulations did not occur. CRP, C3c, C4 and circulating immune complexes tended to normalization.

Arthritis, Rheumatoid↗

PubMed1991

[Macrophage activity during high dose steroid pulse therapy and 7S-immunoglobulin administration in patients with collagenoses. Comparison with in vitro studies].

Patients with connective tissue diseases show increased neopterin levels indicating the activation of the monocyte system. Corticosteroids reduce the release of neopterin in vivo and in vitro. After i.v. 7S-Ig administration neopterin increases in vivo transiently and decreases beyond the pretherapeutic levels. Addition of 7S-Ig to cell cultures reduces the macrophage activation.

Arthritis, Rheumatoid↗

PubMed1990

Major pitfalls in Doppler investigations. Part II. Low flow velocities and colour Doppler applications.

Many pitfalls result from the limited ability of Doppler instruments to record low flow velocities. These include a misleading resistance or pulsatility index due to diastolic cut-off and taking no signal to equal no flow assuming that no signal means no flow. Comparison of actual flow velocities as measured in an in-vitro system (range: 0.8 to 3.4 cm/s) with the lowest recordable spectral or colour signals in 3 Duplexscanners showed that reduced sensitivity to low flow velocities is not only dependent on the high pass ("wall") filter setting, Doppler frequency or angle of incidence, but also on factors such as vessel diameter, impairing the signal to noise ratio. Characteristic errors of colour flow mapping (misleading vascular anatomy, imitation of pathological findings, erroneous exclusion of flow) are due to partial volume effect, limited temporal and velocity resolution, changing angle of incidence, aliasing and failure to detect low flow velocities.

Adult↗

PubMed1990

Major pitfalls in Doppler investigations with particular reference to the cerebral vascular system. Part I. Sources of error, resulting pitfalls and measures to prevent errors.

Major pitfalls in Doppler investigations are presented based on 340 evaluated cerebral Doppler examinations in infants. Substantial pitfalls may result from: A. Physics of sound waves and Doppler instruments (errors due to high pass filter cut off, aliasing, rapid image update). B. Quality and adjustment of the Doppler instrument (errors due to low sensitivity, inappropriate adjustment of Doppler controls, inadequate wall filter). C. Examination technique (errors due to an unfavourable angle of incidence or due to transducer-induced pressure: decrease predominantly in diastolic flow velocity-increase in maximum flow velocity in the straight sinus). D. Hemodynamics (errors due to spatial or temporal variations of the flow profile, pulsatility, non-uniform distribution of cerebral blood flow/CBF). E. Cerebral vascular anatomy (errors due to an unfavourable probe position as related to the three-dimensional arrangement of vessels, inadequate separation of closely adjacent vessels). F. Interpretation (flow velocity or Resistance Index/RI is taken to equal CBF, RI is taken to equal peripheral vascular resistance, one artery is taken to represent the cerebral circulation). Pitfalls may be avoided by using adequate means (low wall filter adjustment, high Doppler frequency, critical assessment of velocity spectra) to reduce the likelihood of errors occurring.

Adolescent↗

PubMed1990

[Granulomatous thrombophlebitis in Lyme borreliosis--case report].

The presented case report shows a patient with Lyme disease who also developed thrombophlebitis saltans. Histopathologically we found a granulomatous perivasculitis, an immunohistological investigation showed deposits of IgG, IgA, IgM, C3 and C4 in the vessels. Antibody titers against Borrelia burgdorferi were elevated, but no anti-cardiolipin antibodies were found. A pathogenetic correlation due to anti-phospholipid antibodies that have been found in thrombosis and borreliosis or a vasculitis vasorum comparable to a previously described vasculitis nervorum might be discussed.

Antibodies, Bacterial↗

PubMed1990

[Hemodynamic and lung function analytic findings in so-called collagen diseases].

Twenty-four patients with connective tissue disease as defined by ARA criteria were submitted to a thorough cardiological and pulmonary diagnostic evaluation. Mean pulmonary arterial pressure was elevated in 54 per cent of the patients, a left-ventricular functional disorder taking the form of elevated pulmonary capillary occlusive pressure was almost equally as frequent. Interindividual comparisons suggest only a low progressivity of the cardiac involvement, while pulmonary involvement progresses rapidly, to become the prognostically predominating factor. This suspicion must be checked by performing follow-up examinations with repeated cath. examinations of the right heart in individual patients. In common with ACE determinations, haemodynamically effective pericardial disorders are of no significance in connective tissue diseases. Patients with "collagenosis" should be submitted to right-heart catheterisation early on. Attempts at therapy taking the form of aggressive treatment of the underlying disease or administration of nitrates or calcium antagonists, would appear meaningful.

Adult↗

PubMed1989

Immunomodulating therapy of rheumatoid arthritis by high-dose intravenous immunoglobulin.

11 patients with rheumatoid arthritis were treated with intravenous immunoglobulin (IVGG). In 6 patients clinical results were impressive, although lasting responses could be achieved in 3 patients only. This treatment was immunomodulating, since the immunoregulatory T-cell ratio (CD4/CD8) decreased following therapy by reducing CD4-positive cells in-vivo. By use of anti-mu-antibodies as a B-cell specific mitogen, IVGG-treatment was seen to suppress early processes of B cell activation. In parallel to these cellular effects, IVGG led to a reduction in the levels of polyethyleneglycol-precipitated circulating immune complexes as measured by lasernephelometry.

Adult↗

PubMed1989

Duplex-scanning of the deep venous drainage in the evaluation of blood flow velocity of the cerebral vascular system in infants.

Doppler investigations of the anterior cerebral (pericallosal) or internal carotid arteries have two major limitations: (1) flow velocity in one cerebral artery does not necessarily represent flow velocity in other cerebral arteries; (2) flow velocity spectra are influenced significantly by transducer-transferred pressure. Furthermore, there are substantial pitfalls in the interpretation of arterial flow velocity data. We therefore examined Doppler-shift waveforms of the deep venous drainage in addition to arterial flow velocity recordings in 186 infants, including a reference group of 49 infants without significant disease. In this group, mean values of peak velocities were 13.2 cm/s, 5.6 cm/s, 5.9 cm/s and 5.6 cm/s for the straight sinus, the vein of Galen, the right and the left basilar veins respectively. Venous flow velocities were increasing significantly with age, but not or only marginally with the weight at the time of examination. Three main flow velocity patterns were observed: (1) bandlike (straight sinus 25%, vein of Galen 59% and basilar veins 63%); (2) sinusoid and synchronous with arterial pulse (46%, 27% and 29% respectively; (3) intermittent (3%, 0% and 0% respectively). In contrast to the reference group, the intermittent pattern was common in severely ill premature infants and was associated with increased intrathoracic pressure and adverse outcome, indicating reduced venous volume flow irrespective of the arterial flow velocity pattern. Although difficult to perform, transcranial and transfontanellar Duplex-scanning of the deep cerebral veins might help to avoid pitfalls of arterial velocity interpretation, reveal further pathophysiological aspects of intensive care and be an important factor for the prediction of outcome.

Blood Flow Velocity↗

PubMed1989

[Doppler sonographic findings in intraocular tumors].

B-scan-ultrasonography combined with Doppler measuring facilities (DUPLEX technology) was applied in 31 patients with intraocular tumors (27 choroidal melanomas, 4 cavernous hemangiomas of the chorioid). In all but 2 patients, Doppler frequency shift was observed inside the tumor, which was interpreted as being caused by high-velocity blood flow (maximum 10 cm/s). After conservative treatment (beta irradiation with ruthenium 106) the Doppler signals decreased in height in some patients. After 6-8 months, no frequency shift could be determined. Choroidal hemangiomas showed similar signal behavior, so that differential diagnosis by means of Doppler analyses does not seem to be possible.

Aged↗