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Biomedical subjects

R Bos

Publications and source records attributed to R Bos.

At least 73 records · Page 4Linked to original sources
PubMed1992

Treatment of stones in caliceal diverticula: extracorporeal shock wave lithotripsy versus percutaneous nephrolitholapaxy.

Stones in caliceal diverticula may cause symptoms for which treatment is indicated. Both extracorporeal shock wave lithotripsy (ESWL) and percutaneous nephrolitholapaxy (PNL) are recommended. We have evaluated the results of ESWL treatment of stone-containing caliceal diverticula and compared these with the results obtained by percutaneous surgery. In the ESWL group, 15 patients were treated with an electromagnetic lithotriptor (Siemens Lithostar). After 3 months, plain abdominal X-rays revealed that only 2 patients were both stone-free and symptom-free. Of the 13 patients with residual fragments, 7 had no symptoms. The remaining 6 were treated by a lower pole resection (n = 3), a percutaneous procedure (n = 2) and long-term administration of antibiotics (n = 1). Sixteen patients were treated percutaneously. Puncture failed in 3 and they underwent a lumbotomy. In the remaining 13 patients the stones were reached by direct puncture (n = 12) or via an adjacent calix (n = 1). After 3 months, 10 patients were stone-free and had no symptoms. Morbidity consisted of post-operative bleeding (n = 3) and high fever (n = 1). It was concluded that caution should be exercised in the treatment of stone-containing caliceal diverticula. Only in symptomatic cases is treatment indicated and ESWL is the first choice. If ESWL fails (residual stones and persistent symptoms), PNL should be performed, although it is associated with a higher morbidity rate.

Diverticulum↗
PubMed1991

Cost-effectiveness of environmental management for vector control in resource development projects.

Vector control methods are traditionally divided in chemical, biological and environmental management approaches, and this distinction also reflected in certain financial and economic aspects. This is particularly true for environmental modification, usually engineering or other structural works. It is highly capital intensive, as opposed to chemical and biological control which require recurrent expenditures, and discount rates are therefore a prominent consideration in deciding for one or the other approach. Environmental manipulation requires recurrent action, but can often be carried out with the community participation, which raises the issue of opportunity costs. The incorporation of environmental management in resource projects is generally impeded by economic considerations. The Internal Rate of Return continues to be a crucial criterion for funding agencies and development banks to support new projects; at the same time Governments of debt-riden countries in the Third World will do their best to avoid additional loans on such frills as environmental and health safeguards. Two approaches can be recommended to nevertheless ensure the incorporation of environmental management measures in resource projects in an affordable way. First, there are several examples of cases where environmental management measures either have a dual benefit (increasing both agricultural production and reducing vector-borne disease transmission) or can be implemented at zero costs. Second, the additional costs involved in structural modifications can be separated from the project development costs considered in the calculations of the Internal Rate of Return, and financial support can be sought from bilateral technical cooperation agencies particularly interested in environmental and health issues. There is a dearth of information in the cost-effectiveness of alternative vector control strategies in the developing country context. The process of integrating vector control in the general health services will make it even more difficult to gain a clear insight in the matter.

Animals↗
PubMed1988

Saint Lucia revisited.

The eastern Caribbean island of Saint Lucia is now famous in parasitological history as the setting for a major programme of schistosomiasis control'. Perhaps less well-known are the island's effective control of many intestinal parasites, and elimination of malaria, such that the current patterns of mortality and other demographic indicators now resemble those of industrialized countries. More recently, the island has become the focus for another community-based health programme as the Caribbean region again comes to grips with Aedes aegypti and its recently imported relative, Aedes albopictus, important vectors of yellow fever and dengue viruses (see Box 1).

Journal Article↗
PubMed1987

Financial and economic aspects of environmental management for vector control.

Short term economic benefits of resource development generally carry more weight in political decision-making than the adverse health effects such projects may have in the medium and long term. This problem is particularly acute in the case of water resource development projects which can often promote the prevalence and incidence of certain vector-borne diseases such as schistosomiasis and malaria. And while the agricultural sector is usually strengthened by production increase resulting from water resource development, the health sector may ultimately have to pick up the bill for disease control programmes which become necessary as a consequence. At its sixth meeting in Geneva, the WHO/FAO/UNEP Panel of Experts on Environmental Management for Vector Control (PEEM) discussed the financial and economic aspects of environmental management, and its cost effectiveness as a vector control measure. Their report is now available and in this article, Robert Bos and Anne Mills discuss some of the key findings.

Journal Article↗
PubMed1986

Cyclic tetramolecular complexes of monoclonal antibodies: a new type of cross-linking reagent.

A simple and efficient procedure for the construction of bifunctional molecules is described and their use in a variety of applications documented. This procedure is based on our observation that mouse IgG1 monoclonal antibodies, when mixed with equimolar amounts of a high-affinity rat monoclonal antibody specific for mouse IgG1, yield uniform cyclic tetramolecular complexes each consisting of two mouse and two rat antibodies as shown by gel electrophoresis and electron microscopy. When solutions of two mouse antibodies (e.g. a and b) are mixed prior to the formation of complexes with the rat antibody, stable bispecific (a X b) complexes together with monospecific (a X a and b X b) complexes are obtained. Bispecific complexes prepared in this way were able to efficiently bind peroxidase to cell surface antigens, and to bind red blood cells to selected nucleated cell types present in heterogeneous populations. Tetrameric antibody complexes are more easily prepared than bispecific antibodies or bifunctional antibodies produced by transfection of myelomas with recombinant genes. They also have the advantage that the antigen-binding properties of the bivalent monoclonal antibodies are not compromised. Tetrameric antibody complexes thus represent a powerful new type of cross-linking reagent that may have a wide spectrum of applications in biology and medicine.

Animals↗
PubMed1985

The essential oil of Apium graveolens var. secalinum and its cercaricidal activity.

The composition of the essential oil of the fresh aerial parts of Apium graveolens var. secalinum at its flowering stage, obtained from three different locations in Egypt, was investigated. The identification of the components of this oil was carried out by means of analytical GC and GC-MS. The main components in the oil are: alpha- and beta-pinene, myrcene, limonene, cis-beta-ocimene, gamma-terpinene, cis-allo-ocimene, trans-farnesene, humulene, apiol, beta-selinene, senkyunolide and neocnidilide. Data concerning the relative concentrations of the main components of the different celery oil samples are given. The cercaricidal effect of the essential oil has been examined on cercariae, being one of the stages in the life cycles of Schistosoma mansoni, which causes schistosomiasis. The essential oil showed in addition to a cercaricidal effect also a chemotactic effect.

Animals↗
PubMed1985

Late purulent pacemaker pocket infection caused by staphylococcus epidermidis: serious complications of in situ management.

The pathophysiology of late pacemaker pocket infection is poorly understood. We report three cases of late infection caused by Staphylococcus epidermidis. Despite initial local conservative management ultimate removal of the entire pacing system was required. In late pacemaker pocket infection we recommend initial removal of the entire pacing system and replacement on the contralateral side. When retrieval of the lead system requires open-heart surgery epicardial wires should be placed.

Aged↗
PubMed1983

The composition of the essential oil in the leaves of Coleus aromaticus Bentham and their importance as a component of the species antiaphthosae Ph. Ned. Ed. V.

The leaves of Coleus aromaticus Bentham were used in the East Indian archipelago, mainly in cases of aphthous stomatitis. For this purpose the Dutch Pharmacopoeia Ed. v introduced the Species antiaphthosae with Coleus leaves as an active component, because of their antiseptic qualities. Older research ascribed this activity to carvacrol and perhaps thymol. However, in more recent research in India eugenol and methyleugenol were also found to occur in this oil. Our investigations on original leaves from Java by GC-MS showed the absence of eugenol and methyleugenol, which leads us to the conclusion that on Java another chemotype occurs.

Chromatography, Gas↗
PubMed1979

[Epidemiological aspects of Uncinaria stenocephala infections in the Netherlands (author's transl)].

A series of experimental infections in a total number of twenty-two dogs showed that transmission of the parasite Uncinaria stenocephala from one dog to another is readily achieved by oral route. Cutaneous infection was only successful when large doses were used. From the topographical distribution of some intestinal U. stenocephala worm populations in dogs it was concluded that the hookworm population is concentrated in the proximal part of the ileum. The expulsion of worms observed may be evidence of the size or persistence of the worm population. The prepatent period was found to be (at least) thirteen days, both in dogs and in foxes. Daily worm-egg counts showed a fluctuating rhythm, particularly during the first 2-3 weeks of the patent period. Relatively high peaks were also recorded in some cases. The maximum number of worms eggs was estimated at well over 5,000 eggs per female U. stenocephala worm (in dogs). U. stenocephala eggs and larvae are capable of surviving at low temperatures. U. stenocephala infection was found to be present in twenty-five (86 per cent) out of twenty-nine foxes obtained and examined in 1975, the worm load varying from one to 176 hookworms and averaging thirty worms per fox. From the preliminary results of a number of experimental transmissions it was concluded that foxes and dogs harbour adapted strains of U. stenocephala, which prevents cross infections between these reservoirs from occurring to more than a limited extent.

Ancylostomatoidea↗
PubMed1977

Distribution of some hydrocarbons in ambient air near Delft and the influence on the formation of secondary air pollutants.

The relative concentrations of hydrocarbons in the atmosphere may provide information concerning their origin. It appears that the hydrocarbon composition measured in Delft (The Netherlands) is entirely different for northern and southern wind directions. This points to different sources. The most important sources for this area are natural gas leaks, traffic, and (petrochemical) industries. It appears that the relative potential of the precursor mix to form peroxyacetylnitrate (PAN) and ozone is also different for both wind directions.

Air Movements↗