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Biomedical subjects

C Helbing

Publications and source records attributed to C Helbing.

At least 19 recordsLinked to original sources
PubMed1996

Characterization of a Rana catesbeiana hsp30 gene and its expression in the liver of this amphibian during both spontaneous and thyroid hormone-induced metamorphosis.

During metamorphosis, the Rana catesbeiana tadpole undergoes developmental changes in almost every tissue/organ. These changes prepare the ammonotelic, swimming larva for its transition to a ureotelic, terrestrial adult, and involve dramatic remodeling. The postembryonic changes in this tadpole are initiated by the thyroid hormones (TH) and result in the extensive degradation of proteins and degeneration of tissues characteristic of the larval phenotype and in the de novo synthesis of proteins characteristic of the adult phenotype. We questioned whether the drastic nature and abruptness of the TH-dependent, postembryonic changes occurring in the tissues of this tadpole might be perceived by the cells in some tissues as stressful and, therefore, cause them to express heat shock and/or stress-like proteins. To address this question, we isolated and characterized a Rana catesbeiana hsp30 gene and used sequences from it to determine if mRNAs encoded from it, or other members of this gene family, are expressed in tissues of tadpoles undergoing metamorphosis. Our results demonstrate that the liver of metamorphosing Rana catesbeiana tadpoles accumulate hsp30 mRNAs and express the heat shock proteins they encode. The fact that the expression of these hsp30s in the liver of these tadpoles is coincidental with the TH-induced expression of genes encoding the liver-specific urea cycle enzymes suggests that TH may influence, directly or indirectly, the expression of these hsp30 genes and, moreover, implies that the presence of one or more of these heat shock proteins may be necessary for the developmental transitions occurring in this organ.

Amino Acid Sequence↗
PubMed1992

Sequential up-regulation of thyroid hormone beta receptor, ornithine transcarbamylase, and carbamyl phosphate synthetase mRNAs in the liver of Rana catesbeiana tadpoles during spontaneous and thyroid hormone-induced metamorphosis.

During both spontaneous and thyroid hormone (TH)-induced metamorphosis, the Rana catesbeiana tadpole undergoes postembryonic developmental changes in its liver which are necessary for its transition from an ammonotelic larva to a ureotelic adult. Although this transition ultimately results from marked increases in the activities and/or de novo synthesis of the urea cycle enzymes, the precise molecular means by which TH exerts this tissue-specific response are presently unknown. Recent reports, using RNA from whole Xenopus laevis tadpole homogenates and indirect means of measuring TH receptor (TR) mRNAs, suggest a correlation between the up-regulation of TR beta-mRNAs and the general morphological changes occurring during amphibian metamorphosis. To assess whether or not this same relationship exists in a TH-responsive tissue, such as liver, we isolated and characterized a cDNA clone containing the complete nucleotide sequence for a R. catesbeiana urea cycle enzyme, ornithine transcarbamylase (OTC), as well as a genomic clone containing a portion of the hormone-binding domain of a R. catesbeiana TR beta gene. Through use of these homologous sequences and a heterologous cDNA fragment encoding rat carbamyl phosphate synthetase (CPS), we directly determined the relative levels of the TR beta, OTC, and CPS mRNAs in liver from spontaneous and TH-induced tadpoles. Our results establish that TH affects an up-regulation of mRNAs for its own receptor prior to up-regulating CPS and OTC mRNAs. Moreover, results with cultured tadpole liver demonstrate that TH, in the absence of any other hormonal influence, can affect an up-regulation of both the TR beta and OTC mRNAs.

Amino Acid Sequence↗
PubMed1991

Medicare expenditures for physician and supplier services, 1970-88.

The trend data in this article focus on Medicare expenditures and allowed charges for physician and supplier services rendered during the period from 1970 through 1988. A brief overview is presented on the provisions of the new Medicare physician payment system mandated by Congress and scheduled to be phased in starting January 1, 1992. The data provide one of the baselines that could be used for measuring and evaluating the impact of the new Medicare payment system for physician services.

Abstracting and Indexing↗
PubMed1991

Medicare short-stay hospital services by diagnosis-related groups.

The 1983 amendments to the Social Security Act (Public Law 98-21) provided for a prospective payment system (PPS), effective October 1, 1983, for most short-stay hospitals certified to provide inpatient services to Medicare beneficiaries. A brief description of the assignment process for diagnosis-related groups (DRGs) is presented, because assigning a DRG code to a short-stay hospital discharge record is tantamount to the Medicare prospective payment to the hospital, subject to certain statutory adjustments. Shifts in the distribution of the discharges and average length of stay among the DRGs since 1983 reflect the adaptation of hospitals to the incentives embedded in PPS and the ongoing refinements in the methods of assigning DRGs to discharges from short-stay hospitals. Interpretation of the shifts is based on a consideration of the significant refinements in the medical coding system, the technological and scientific advances in the practice of medicine, the effect of shifting patient treatment to alternative sites, policy or legislative changes affecting Medicare coverage, and the annual recalibration of the DRG weights.

Data Collection↗
PubMed1990

Use of Medicare data in international comparisons.

This paper provides a detailed description of the statistical systems of the U.S. Medicare program and discusses how these data bases can be used for health policy analyses and for international comparisons of health systems at the microeconomic level. First, the Medicare program in the context of the entire U.S. health care financing and delivery system is described. Second, the Medicare data collection process and the detailed data elements collected as part of the various Medicare administrative and research data bases are discussed in detail. Third, the use of these microdata for international comparisons of medical effectiveness, incentive effects of alternative reimbursement systems, technology assessment, service use by consumers, and industry impacts is suggested. International comparisons of health systems based on microdata are essential for understanding the underlying dynamics of health systems as well as for attributing performance to specific features or policies.

Centers for Medicare and Medicaid Services, U.S.↗
PubMed1990

Hospital outpatient services under Medicare, 1987.

Presented in this article are data related to hospital outpatient services provided for aged and disabled Medicare beneficiaries during calendar year 1987. Trend data are also presented for selected calendar years 1974-87. Hospital outpatient covered charges and Medicare program payments (in total and per enrollee) are the statistics employed to measure the use of hospital outpatient services. The data contained in this article should provide information to help identify trends and patterns of care for monitoring the Medicare hospital outpatient services.

Aged↗
PubMed1989

Use and cost of physician and supplier services under Medicare, 1986.

There is general consensus that the present Medicare physician payment system and related policies should be revised. Therefore, the Health Care Financing Administration and Congress are examining the physician reimbursement system for potential changes that could reverse the inflationary incentives in the present system and induce greater incentives for efficiency and cost savings. Medicare program data and information are provided to assist health care managers and administrators in the development and analysis of Medicare physician research and policy initiatives. The data may also be helpful in monitoring and measuring the use and cost of Medicare physician and supplier services as related to program performance and administration.

Aged↗
PubMed1989

Use and cost of short-stay hospital inpatient services under Medicare, 1986.

This article is part of a continuing effort to monitor the operation of the Medicare program. A synopsis is given of the legislation that implemented the prospective payment system for short-stay hospitals, and the data show the program experience for 1986, the third full year of implementation under prospective payment.

Data Collection↗
PubMed1988

Use of specialty hospitals by Medicare beneficiaries, 1985.

Information is provided on the use and cost of inpatient services for Medicare beneficiaries discharged from participating specialty hospitals during 1985. Specialty hospitals include: psychiatric, general long-term, rehabilitation, children's, alcohol and drug, and Christian Science sanatoriums. Specialty units of short-stay hospitals are not included in the specialty hospital data presented in this article.

Data Collection↗
PubMed1988

Use and cost of hospital outpatient services under Medicare, 1985.

Presented in this article are program data on the use and cost of hospital outpatient (HOP) services rendered to aged and disabled Medicare beneficiaries during calendar year 1985. Trend data are also presented for calendar years 1974-85. The data shown in this article focus on charges, reimbursements, and reimbursements per enrollee as a means of measuring the cost of HOP services. The data provide information to help identify trends and patterns of care for monitoring the Medicare HOP benefit and for evaluating the impact of the inpatient hospital prospective payment system (PPS) on the use and cost of HOP services.

Ambulatory Care↗
PubMed1988

Use and cost of home health agency services under Medicare.

Presented are 1986 data and trend data (1974-86) on the use and cost of home health agency services rendered to aged and disabled Medicare beneficiaries. Since 1974, reimbursements for these services have grown more rapidly than overall Medicare expenditures. From 1974 to 1986, Medicare expenditures for these services increased from $141 million to $1.8 billion, an average annual rate of 24 percent. HHA reimbursements, however, continue to represent only a small proportion (3.6 percent in 1986) of all Medicare expenditures.

Aged↗
PubMed1988

Medicare: short-stay hospital services, by leading diagnosis-related groups, 1983 and 1985.

Assigning a code from any of the diagnosis-related groups to a short-stay hospital discharge covered by Medicare is tantamount to the Medicare payment to the hospital, subject to certain statutory adjustments. Therefore, diagnosis-related groups are the backbone of the prospective payment system implemented October 1, 1983. However, methods employed in the assignment of diagnosis-related groups have changed since the prospective payment system was introduced. The focus of this article is to note some of these changes in methods of assigning diagnosis-related groups, which may have caused some of the migrations, or shifts, from one diagnosis-related group to another during the period 1983-85.

Diagnosis-Related Groups↗