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Biomedical subjects

H L Smits

Publications and source records attributed to H L Smits.

At least 73 records · Page 4Linked to original sources
PubMed1984

Human duodenal gland (Brunner's gland) mucus glycoprotein analysis.

A mucus glycoprotein of the duodenal gland is characterized. The glycoprotein was isolated from a water-soluble homogenate fraction of the submucosal tissue of the most proximal part of the small intestine, containing the duodenal gland, and was purified from contaminating protein by two sequential equilibrium-centrifugation steps in CsCl density gradients. Structural analysis of the purified glycoprotein showed two regions in the protein core: one part characterized by the presence of essentially all of the cysteine residues and another by the presence of most of the serine and threonine. Carbohydrate was found linked to the latter part. Rat (H. L. Smits, P. J. M. van Kerkhof, and M. F. Kramer (1982) Biochem. J. 203, 779-785.) and human duodenal gland mucus glycoprotein show homology in chemical composition. Both glycoproteins have a relatively high protein content and contain little sulfate and no neuraminic acid. In man the mucus glycoprotein, however, has a higher content of serine plus threonine, a lower content of N-acetylglucosamine, a slightly higher content of fucose, and a lower molar ratio of N-acetylgalactosamine relative to serine plus threonine.

Amino Acids↗
PubMed1984

Incentives in case-mix measures for long-term care.

Several States now use patient-based payments for skilled nursing facilities and intermediate care facilities; others are in the process of developing case-mix systems. The Health Care Financing Administration is working under congressional mandate to develop a prospective case-mix system for Medicare payments to skilled nursing facilities. If new payment methods follow the existing pattern, they will be based not on the patient's clinical characteristics but rather on a mixture of clinical characteristics and services delivered. As a result, innate incentives are contained in data collection systems which are cost-increasing at best and dangerous at worst. A preferable approach would be to develop payment schemes based on the patient's degree of dependence.

Centers for Medicare and Medicaid Services, U.S.↗
PubMed1984

Variation in resource use within diagnosis-related groups: the severity issue.

Several authors have suggested that diagnosis-related groups (DRG's) make inadequate allowance for the severity of illness. Before modifications of DRG's are developed, the sources of within-group variation must be precisely defined; not all variation is attributable to the severity of illness. The limitations of the Uniform Hospital Discharge Data Set (UHDDS), of the International Classification of Diseases, Ninth Revision, Clinical Modification coding system and of the original rules of DRG construction must be evaluated and, if necessary, corrected before new approaches to groupings are considered. The most promising potential modifications of existing groups and weights are those that make use of the UHDDS, or of the UHDDS plus additional diagnoses and procedures. The addition of entirely new data elements to the discharge abstract and the pricing process should be considered only as a last resort.

Costs and Cost Analysis↗
PubMed1984

16,16-Dimethyl prostaglandin E2 stimulates galactose and glucosamine but not serine incorporation in rat gastric mucous cells.

It has been suggested that the cytoprotective effect of prostaglandins could be mediated by an increased mucus glycoprotein secretion in the stomach. In the rat we studied the mucus glycoprotein synthesis after an in vivo treatment with 16,16-dimethyl prostaglandin E2 (10 micrograms/kg X day subcutaneously) for 1 h or 7 days. The incorporation rate of [3H]galactose, [3H]glucosamine, and [3H]serine was determined by light microscopic autoradiography in the ex vivo vascularly perfused stomach. Prostaglandin increased the rate of [3H]galactose and [3H]glucosamine incorporation twofold to fourfold in the fundic surface mucous cells; but the total protein synthesis as measured by [3H]serine incorporation was not increased. Analyses of purified mucus glycoprotein did not show an effect on carbohydrate composition, oligosaccharide chain size, nor on buoyant density, after prostaglandin treatment. The present study reveals that 16,16-dimethyl prostaglandin E2 stimulates the mucus glycoprotein synthesis in the fundic mucous cells. This effect may well be one of the mechanisms by which prostaglandin protects the stomach against noxious agents.

16,16-Dimethylprostaglandin E2↗
PubMed1984

The clinical context of technology assessment.

One important aspect of the evaluation of a new medical technology is the clinical context in which the technology will be used. This context includes the disease to be diagnosed or treated, alternative methods of diagnosis or treatment, and the epidemiology of both the illness itself and health services. This paper presents a simple clinical paradigm of use in assessing new technologies.

Delivery of Health Care↗
PubMed1983

Terminal alpha (1 leads to 4)-linked N-acetylglucosamine: a characteristic constituent of duodenal-gland mucous glycoproteins in rat and pig. A high-resolution 1H-NMR study.

The structure of the carbohydrate chains of mucous glycoproteins from the gastro-intestinal tract was examined for species- and tissue-specificity. To this purpose, oligosaccharides were released from purified glycoprotein preparations of rat and pig gastric, duodenal-gland and small-intestinal mucus, by alkaline borohydride reductive cleavage. Based on the results of 500-MHz 1H-NMR spectroscopy and of sugar analysis of the total oligosaccharide fractions, terminal GlcNAc, alpha (1 leads to 4)-linked to galactose, appears to be a characteristic constituent of duodenal-gland oligosaccharides. Similarly, NeuAc in alpha (2 leads to 3)-linkage to galactose turns out to be a typical constituent of small-intestinal mucous glycoproteins. In general, glycoproteins from gastric mucus possess larger and more-branched carbohydrate chains than those from duodenal-gland and small-intestinal mucus. Comparing rat and pig, oligosaccharide structures for corresponding tissues are less complex for the former. After fractionation, the rat duodenal-gland oligosaccharides could be characterized by application of 1H-NMR spectroscopy as being branched tetra- up to hexa-saccharide chains, all sharing the italicized trisaccharide element. The chains exhibit microheterogeneity as to the termination by fucose in alpha (1 leads to 2)- or by GlcNAc in alpha (1 leads to 4)-linkage to galactose. The following structures can be proposed for the most abundant rat duodenal-gland oligosaccharides: (table; see text).

Acetylglucosamine↗
PubMed1982

Medicare's nursing-home benefit: variations in interpretation.

The use of skilled-nursing facilities by Medicare beneficiaries as measured in days of care per thousand elderly persons varies considerably from one state to another. To explore the possibility that this variation reflects differences in the administrative interpretation of rules governing coverage, we developed nine hypothetical cases and presented them by telephone to claims reviewers in fiscal intermediaries and professional standards review organizations. Cases were designed to illuminate the reviewers' use of discretion. We observed marked differences both in the reviewers' decisions to cover or not cover patients and in the reasoning behind their decisions. Three of the 18 reviewers decided to cover very few cases; almost half the reviewers decided to cover most of the cases, but not the same ones. In only two cases did the 18 reviewers approach consensus. This variation is a reflection of the complexity of Medicare's coverage rules and its decentralized administration. To reduce variation, we recommend more centralized review with oversight by Medicare's central office rather than by its 10 regional offices. This oversight should include the training of reviewers in a way that focuses on complex cases to improve the consistency of judgment.

Eligibility Determination↗
PubMed1982

Isolation and partial characterization of rat duodenal-gland (Brunner's-gland) mucus glycoprotein.

A mucus glycoprotein was isolated from the duodenal glands of the rat and purified by repeated density-gradient centrifugation. The characterized glycoprotein is unique to the mucous cells of the duodenal glands and is not present in parts of the small intestine devoid of these glands. The chemical composition of the purified glycoprotein is characteristic for glycoproteins of the mucin-type. Its protein content is relatively high and amount to 35% by weight. No neuraminic acid and little sulphate (2%) is present. Evidence is presented that the native glycoprotein is built up from subunits held together via disulphide bridges in a non-glycosylated region of the protein core.

Amino Acids↗
PubMed1981

The PSRO in perspective.

The Reagan administration has proposed a three-year phase-out of the Professional Standards Review Organization (PSRO) program. The resulting debate in the 97th Congress is focusing on conservatives' concerns that the program represents an intrusion into medical practice rather than liberals' fears that physician-based organizations will not conduct rigorous review. There are three possible future directions for PSROs: rapid elimination through budget cuts; retention of some PSROs at current budget levels, which would essentially mean slow starvation; or retention of some PSROs, with major changes in their relation to the federal government. Multiple sources of funding and a linkage of local PSRO budgets to local effectiveness could further enhance the performance of the best PSROs. As national mechanisms of health-care financing change, the role of PSROs should also change; there is a central place for physician-based review in "pro-competitive" health-care-financing systems.

Cost-Benefit Analysis↗
PubMed1981

Glycoprotein synthesis in the mucous cells of the vascularly perfused rat stomach. III. Mucous cells of the antrum and the duodenal glands.

Labeled leucine, serine, galactose, glucosamine, fucose, and sulfate were administered to rat stomachs in a vascular perfusion system. Sections of gastric fundus and antrum, and of the duodenal glands, were studied by light-microscopic autoradiography. The rate of incorporation of radioactive label in the various mucous cell types of the antrum and of the duodenal glands was measured by counting the silver grains over each cell type and comparing this rate with that of the surface mucous cells of the fundus. The following major observations were made: The patterns of incorporation in the mucous cells on the surface and in the pits of the antrum did not differ essentially from those of the surface mucous cells of the fundus. On the contrary, the incorporation patterns of the surface mucous cells of the fundus differed considerably from those of the mucous cells of the antral glands and from the mucous cells of the duodenal glands. The mucous cells of the antral glands showed a lower incorporation rate of amino acids and of (amino) sugars, especially of galactose and glucosamine, but a higher incorporation rate of sulfate. The mucous cells of the duodenal glands showed a considerably higher rate of incorporation for serine, but a lower rate for glucosamine. No differences were seen for leucine, galactose, and sulfate. The relatively low synthetic activity of the mucous cells of antral glands correlates well with the various amounts of RER, Golgi system, and secretory granules, found in these cells, and with the histochemical staining characteristics of their mucous granules. The mucous cells of the duodenal glands are characterized by typical parallel arrays of their numerous RER cisternae and by a low number of small secretory granules.

Animals↗
PubMed1978

Identification of mitochondrial gene products by DNA-directed protein synthesis in vitro.

1. A cell-free system, derived from Escherichia coli is highly active in the linked transcription-translation of yeast mtDNA from both wild-type and petite strains. 2. The products of synthesis are short (Mr less than 10 000) hydrophobic polypeptides, which show a high tendency to aggregate in a specific fashion with E. coli and mitochondrial proteins. Aggregation is extremely persistent: alkali, sodium dodecyl sulphate/urea, guanidinium . HCl and carboxymethylation reduce it, but do not eliminate it completely. 3. Nevertheless, results of indirect immunoprecipitation tests suggest that antigenic determinants of cytochrome c oxidase are among the products synthesized. The immunoprecipitation appears specific by criteria including competition experiments and its absence when mtDNA from low complexity petites, retaining only the gene for 21 S rRNA and some flanking sequences, is used to programme protein synthesis. Electrophoretic analysis of material precipitated by anti-cytochrome c oxidase sera reveals four discrete polypeptides with molecular weights of 7400, 6400, 5000 and 4100, which probably represent polypeptide fragments carrying antigenic determinants of cytochrome c oxidase.

Bacterial Proteins↗
PubMed1975

The primary-care practitioner -- specialist or jack-of-all-trades.

Primary-care physicians, too often viewed as low-level generalists, are more appropriately thought of as specialists whose work demands specific skills. These physicians function as managers, advocates, educators, and counselors for their patients while also serving as co-ordinators of other professionals involved in primary care. The basis for education in primary care should be a recognition of the specialized nature of the work that primary-care physicians perform. Faculty members in primary-care programs should themselves be primary-care physicians; these educators deserve the same titles and status given other clinical specialists within the academic community. The setting of standards for primary-care practice and the design of research into areas such as the quality of care are tasks that should be undertaken by, or in collaboration with, physicians who are primary-care specialists.

Counseling↗