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Biomedical subjects

H A Neumann

Publications and source records attributed to H A Neumann.

At least 55 records · Page 3Linked to original sources
PubMed1997

Factors influencing participation among melanoma screening attenders.

We surveyed the demographic profile and motives prompting to participate among people attending voluntary melanoma screening clinics in Southern Limburg, the Netherlands, in June 1993. Precampaign public announcements addressed only melanoma and its precursor lesions. All attendees completed a detailed questionnaire addressing demographic particulars and specific fixed choice questions on their motivation to attend. There were 4,146 persons attending the screening clinics. Most attendees opted for examination of a specific lesion (71%). More females than males participated. Fear of having skin cancer was an important reason to participate (27%). Of all attenders, 16% had to be convinced by relatives or friends to attend the screens, and 33% would not have visited a physician on their own initiative when there had not been a free screening. Females were more concerned about skin cancer than males. The local and regional newspapers formed the most important precampaign publicity channel. Free melanoma screenings attract large numbers of people. Males are underrepresented. They are less aware of the risk profile of melanoma. Future screenings should target the male population.

Adult↗
PubMed1997

Volunteer melanoma screenings. Follow-up, compliance, and outcome.

BACKGROUND: Follow-up information on free melanoma screening clinics is not readily available. OBJECTIVE AND METHODS: We studied the follow-up, compliance, and outcome of positive screenees after a screening campaign for melanoma in the Netherlands. RESULTS: Of the 4146 participants, 486 (11.7%) had a suspicious premalignant or malignant lesion warranting referral to his or her general physician indicating the proposed line of management. Participants with borderline lesions were not referred. Referral of borderline cases should have resulted in a considerable increase of the number of positive screenees (18.1%). All positive screenees but two gave permission for follow-up. Only 18 screenees (3.7%) were lost during follow-up. Moreover, one screenee with a presumed basal cell carcinoma and six screenees suspicious of having a premalignant lesion decided not to seek medical attention despite several reminders. The positive predictive value for melanoma was 17.2%, and for nonmelanoma skin cancers was 42.9%. CONCLUSION: A selective referral policy may reduce the generated costs of melanoma screenings substantially. Adequate follow-up of positive screenees is mandatory in order to determine the ultimate yield and usefulness of such campaigns.

Biopsy↗
PubMed1997

Elastic compression stockings: durability of pressure in daily practice.

BACKGROUND: Elastic compression stockings are valuable tools in the treatment of many phlebological diseases. As to day no data are available about how long these elastic compression stockings continue to exert enough compression for a proper clinical function. PATIENTS AND METHODS: In this study we measured the pressure at the B level of compression class II and III elastic stockings directly after the patients started to use them, after 1 month, and after 3 months. In total 99 below knee stocking were measured with a TNO-tester, which has officially been accepted by the CEN for measurement of elastic compression stockings. RESULTS: Class II flat knitted stockings showed a mean pressure of 29.3 (SD 4.9) mmHg at the start of the study, declining to 27.6 (SD 5.2) mmHg, and 26.5 (SD 4.4) mmHg, at 1 and 3 months respectively. The round knitted class II had comparable results. In class III flat knitted stockings we measured 47.5 mmHg (SD 8.1) at the start, and 44.2 (SD 7.1) mmHg, and 41.3 (SD 6.7) mmHg, at 1 and 3 months respectively. Extrapolation of the results after 1 and 3 months demonstrate that the mean pressure of class II stocking is less than 25 mmHg after 4 to 5 months. Class III stockings were less than 35 mmHg close to 6 months, if evaluated in the same way. Individual regression analysis show that after 6 months 66% of the pressure class II stockings have a pressure of less than 25 mmHg and 45% of the pressure class III less than 35 mmHg. When considering a 10% safety margin the figures are respectively 84% and 63%. CONCLUSIONS: From the results of this study it can be concluded that, especially for the most frequently used compression class II stockings, three new stockings each year are necessary to ensure an effective function of the stocking during the time they are being used by the patient. For compression class III flat knitted stockings two pairs can be considered as sufficient.

Aged↗
PubMed1996

Effects of medical elastic compression stockings on interface pressure and edema prevention.

BACKGROUND: Although medical elastic compression stockings are widely used in venous diseases their effects on the venous system are still largely unclear. OBJECTIVE: To evaluate the pressure of these medical elastic compression stockings on the skin and their edema protective effects. METHODS: On 18 legs the interface pressure of the stocking on the skin was measured with the aid of an interface pressure measuring instrument (Oxford Pressure Monitor). Five different kinds of medical elastic compression stockings were used. On 11 legs the edema protective effects of the different stockings was evaluated with the use of air-plethysmography. RESULTS: All medical elastic compression stockings used in this study, especially the flat-knitted, showed a good pressure gradient from the B1 level upwards. High pressures were measured at the dorsal foot and the pre-tibial zone. During cuff inflation a special edema protective effect was found in the round-knitted class II stockings. CONCLUSIONS: All class II and III medical elastic compression stockings used in this study have a sufficient pressure (especially class III) and pressure gradient for the treatment of patients with chronic venous insufficiency. Especially round-knitted stockings revealed high pressures on the danger areas such as the dorsal foot. All class II and III stockings provided an effective edema preventive effect; the round-knitted stockings have the best performance, due to their rubber components.

Aged↗
PubMed1996

Transcutaneous oxygen tension in patients with and without pericapillary fibrin cuffs in chronic venous insufficiency, porphyria cutanea tarda and non-venous leg ulcers.

To evaluate the influence of fibrin cuffs on the transcutaneous oxygen tension in patients with chronic venous insufficiency (CVI) we performed a prospective comparative study in an out-patient dermatological department of a district hospital in the Netherlands. 16 patients with CVI grade II or III, 6 patients with porphyria cutanea tarda (PCT) without any sign of CVI, 4 patients with clinical ecthyma type ulcers without CVI and 10 healthy volunteers were studied. Skin biopsies for fibrinogen staining, transcutaneous oxygen tension measurements (TcPO2) and light reflexion rheography (LRR) were performed. TcPO2 readings were significantly lower in patients with CVI compared to patients of the other groups. Fibrin cuffs were found in 8 out of 16 patients with CVI, all PCT patients and 3 out of 4 ecthyma-ulcer patients. On the basis of these results we conclude that the fibrin cuff alone does not act as a barrier for oxygen transport. Fibrin cuffs in CVI are not the cause of venous ulceration but only a part of the complicated mechanism of the altered microcirculation induced by reflux in the venous macrocirculation. Fibrin cuffs are not unique for CVI but an indication of a disturbed microcirculation.

Adult↗
PubMed1996

[Radiation protection through cytokine release by N-acetylcysteine].

BACKGROUND: Interleukin-1, tumornecrosisfactor-alpha and interferon-gamma endogenously provide protection of the hematopoietic system against radiation. Thiols have already been used successfully as radioprotective agents. In this study the effect von N-acetylcysteine (NAC) on the release of interleukin-1 alpha and beta (IL-1), interleukin-2 (IL-2), interferon-gamma (IFN-gamma) and tumornecrosisfactor-alpha (TNF-alpha) was assessed in an in vitro assay. PATIENTS AND METHODS: Whole blood samples from 8 healthy volunteers were stimulated with 7.5 micrograms/ml PHA. NAC was added at concentrations of 0.6, 6, 12 and 24 mmol/l. Subsequently the samples were irradiated with a dose of 18 Gy according to preceding validation experiments. RESULTS: IL-1 alpha, IL-1 beta b and IL-2: In comparison to stimulation and radiation alone the addition of 0.6 and 6 mmol/l, with IL-2 also 12 mmol/l, NAC resulted in a significant increase of the cytokine-concentrations. The highest concentration of 24 mmol/l NAC, however, resulted in a decrease beyond control levels. IFN-gamma and TNF-alpha: Until 12 mmol/l NAC no changes were observed. 24 mmol/l NAC resulted in a significant decrease, too. CONCLUSION: N-acetylcysteine is capable to co-stimulate radioprotective cytokines like IL-1 alpha and IL-1 beta and to enhance IL-2 in vitro, whereas higher doses result in a suppression.

Acetylcysteine↗
PubMed1996

Leucocytoclastic vasculitis induced by prolonged exercise.

Many people develop skin symptoms after long-distance walks, but little is known about the aetiology of these. In this study we took 11 biopsies from 10 long-distance walkers who walked 80 km. All biopsies originated from purpuric lesions on the lower legs, which had appeared during walking. In all 11 specimens, signs of a leucocytoclastic vasculitis were present with leucocytoclasis, exocytosis of erythrocytes and a granulocyte/mononuclear perivascular infiltrate. Immunofluorescence investigations showed deposition of C3c in many specimens and immunoglobulin M in some. The occurrence of a leucocytoclastic vasculitis after prolonged exercise may be explained by the existence of an exercise altered cutaneous microcirculation, complement activation and an altered immune function.

Complement C3c↗
PubMed1996

Total skin examination during screening for malignant melanoma does not increase the detection rate.

Total skin examination during public screening for malignant melanoma is often advocated, but the benefit of this approach has not been established properly. We assessed the yield of examination of the entire skin, in addition to examination of intentionally shown skin lesions, in people attending melanoma screening clinics in southern Limburg, the Netherlands, in 1993. Of the 4146 attenders, 2910 (70%) showed a specific skin spot. Additional examination of the entire skin was offered to 1385 people. There were 1221 evaluable cases. Fourteen presumptive diagnoses of malignancies were encountered: seven malignant melanomas, all with low clinical suspicion, and seven basal cell carcinomas. Histology revealed three basal cell carcinomas. No malignant melanomas were confirmed by histology. It is concluded that additional total skin examination during screening for malignant melanoma is not worthwhile, except perhaps for persons presenting lesions that are suspicious of melanoma or dysplastic naevi.

Basal Cell Carcinoma↗
PubMed1995

Expression of the apoptosis-suppressing protein Bcl-2 in non-melanoma skin cancer.

Basal cell carcinoma (BCC) is typically a slow-growing malignant tumour, composed of cells similar to those in the basal area of the epidermis. We investigated the expression of bcl-2 (B-cell leukaemia/lymphoma-2) in BCC, and also in squamous cell carcinoma (SCC) of the skin. The proto-oncogene bcl-2 encodes a protein which inhibits programmed cell death (apoptosis). The protein is expressed in basal cells in normal human epithelium, but not in the suprabasal cell layers. Immunohistochemical localization using a monoclonal anti-Bcl-2 antibody revealed bcl-2 expression in all the BCCs (15 patients). SCCs did not express bcl-2 (five patients). The positive Bcl-2 staining of BCC tumour cells supports the hypothesis that BCCs originate from the basal layer of the epidermis. The bcl-2 expression of BCC tumour cells also suggests a neoplastic transformation caused by extended cell survival rather than increased cell proliferation. This type of neoplastic growth is possibly associated with less aggressive tumour behaviour.

Apoptosis↗
PubMed1995

A comparative clinical trial of graduated compression stockings and O-(beta-hydroxyethyl)-rutosides (HR) in the treatment of patients with chronic venous insufficiency.

As overall conclusions from this study, and the two preceding comparable trials in which TcPO2 was measured in patients with (8) and without (7) stockings, we propose that: All patients with symptoms and oedema of CVI should be advised to wear suitable compressive stockings (this study); if they do wear stockings, then additional benefit may be derived from treatment with HR (8); for patients who are reluctant to wear stockings, for a variety of reasons, or in whom stockings may be contraindicated (e.g. mixed arterio-venous disease), then HR is an acceptable alternative (7 and this study).

Adult↗
PubMed1995

Vein biopsy. A new indication for Muller's phlebectomy.

BACKGROUND: Histology can be essential for certain diagnoses. In venous diseases, especially in some syndromes and angiodysplasia, a vein biopsy can be helpful as well. OBJECTIVE: To describe an easy method of vein biopsy. METHOD: In Muller's phlebectomy, a micro incision is made in the skin overlining the vein. The vein is hooked with a special hook. Skin is closed with a steristrip. RESULTS: Muller's phlebectomy turned out to be an excellent method for harvesting material from veins. CONCLUSIONS: With the described method it is possible to harvest enough material for histologic diagnosis with little or no discomfort to the patient and excellent cosmesis.

Adult↗