Biomedical subjects

R L Carter

Publications and source records attributed to R L Carter.

At least 91 records · Page 5Linked to original sources

PubMed1988

Prospective pricing model for neonatologists and obstetricians in tertiary care centers.

According to the new federal diagnosis-related group (DRG) system, hospitals are reimbursed fixed sums based on discharge diagnoses, rather than variable sums that depend on specific goods and services consumed and number of days hospitalized. The government is now exploring DRGs as a potential mechanism for reimbursing physicians. In Florida, two DRG-type reimbursement systems were developed for neonatal and obstetrical hospitalizations in tertiary care settings, as departures from the federal DRG system. Called neonatal care groups (NCGs) and obstetrical care groups (OBCGs), both classification systems predicted hospital charges in these settings more accurately than did federal DRGs. The feasibility of a prospective pricing system for neonatologists and obstetricians based on NCGs and OBCGs was investigated. The data showed that neonatologists' charges had a high correlation with hospital charges (r = .90) and that increasing levels of intensity of care as defined by the NCGs were reflected by consistent increases in reimbursement to neonatologists. If the NCG system were to be applied, neonatologists would receive compensation equivalent to that which they currently earn according to the fee-for-service system. In contrast, obstetricians' charges bore almost no relationship to hospital charges. However, modest differences in obstetrician's charges did emerge as a reflection of number of complications, which are incorporated into the OBCG categories; this suggests that a reimbursement system based on hospital OBCG categories might be applied to obstetricians.

Diagnosis-Related Groups↗

PubMed1987

Prospective pricing system by diagnosis-related groups: comparison of federal diagnosis-related groups with high-risk obstetric care groups.

Of 468 diagnosis-related groups identified by the federal government for Medicaid reimbursement, 15 are related to obstetric hospital care. Each diagnosis-related group is considered a distinct group in which cases are homogeneous with respect to resource consumption. Because the diagnosis-related group system is based primarily on data from community and secondary care hospitals, it does not differentiate sufficiently among high-risk obstetric patients seen at tertiary care institutions, such as Florida's Regional Perinatal Intensive Care Centers. We developed an alternative scheme for diagnosis-related groups, called obstetric care groups, using the federal diagnosis-related groups as the model from which to depart. Data collected for 4192 women during a 2 1/2-year period indicate that obstetric care groups provide more homogeneous groups than diagnosis-related groups for our population of high-risk patients. The obstetric care groups differentiate between no complications, one complication, and two or more complications, while the diagnosis-related groups differentiate only between no complications and one or more complications. Also, complications for obstetric care groups are based on only 19 diagnoses that contribute significantly to resource consumption, while the list of possible complications exceeds 200 for diagnosis-related groups. Although the obstetric care group classification system is simpler than that for diagnosis-related groups, it results in a more accurate reimbursement of hospitalization charges for high-risk obstetric care.

Diagnosis-Related Groups↗

PubMed1987

Radical neck dissections for squamous carcinomas: pathological findings and their clinical implications with particular reference to transcapsular spread.

Two hundred fifty radical neck dissections, undertaken for mucosal squamous carcinomas of the head and neck, were reviewed with reference to pathological findings and their clinical implications. No major differences in descriptive surgical pathology were established between irradiated and non-irradiated resections. In general, irradiated dissections had lower total node counts and somewhat fewer nodal metastases involving a smaller number of different nodal groups. The topography of nodal deposits was similar in irradiated and non-irradiated resections. Palpable keratin granulomas (without intact tumor) were almost confined to irradiated patients. Transcapsular spread of tumor from involved lymph nodes was common: it was demonstrated in 160/188 'positive' dissections (85%) and was subclassified as 'macroscopic' in 90 and 'microscopic' in 70. The incidence and extent of transcapsular spread was similar in irradiated and nonirradiated resections. It was more frequently observed in association with large nodal masses but it was also regularly found with small nodal deposits less than 3 cm in diameter. Statistical analyses showed strong associations (p less than 0.0005) between the presence and/or extent of transcapsular spread and subsequent recurrence in the operated neck and overall survival. The predictive value of other clinical and pathological features vis-a-vis local neck recurrence such as numbers of involved nodal groups was weaker. Macroscopic transcapsulr spread emerges as the major prognostic factor for recurrent disease in the neck (p less than 0.0001). Attention is drawn to the advantages of accurate descriptive categories ('macroscopic', 'microscopic') for this critical prognostic feature.

Carcinoma, Squamous Cell↗

PubMed1987

The management of primary lymphoma of bone.

From October 1962 through April 1982, 21 patients with the diagnosis of primary lymphoma of bone (18 monostotic, stages IE and IIE; 3 polyostotic) were treated with curative intent. A combination of chemotherapy and radiation therapy was used in 11 patients, local treatment alone in 9 patients, and chemotherapy alone in one patient. Overall 5-year survival for the patients treated with curative intent was 56%. Standard work-up has changed over the 20-year study period. Five-year survival for the subset of eight stage I and II patients with full pretherapy staging was 83%. Prognosis was significantly correlated with extent of pretherapy staging. Treatment parameters that also seemed to predict outcome were the aggressiveness of chemotherapy and the use of irradiation or surgery for local-regional disease; the only local failure occurred in the patient who received chemotherapy alone. Complications of radiation therapy alone and in combination with chemotherapy are discussed and correlated with irradiation dose. Radiation therapy techniques are described, and a management approach is recommended.

Adolescent↗

PubMed1987

The relationship of Apgar scores, gestational age, and birthweight to survival of low-birthweight infants.

While Apgar scores provide a valid prediction of mortality in term infants (primarily reflecting asphyxia), intervening variables in premature newborns complicate interpretation. Physiologic states normal to preterm infants (such as, decreased muscle tone) can depress scores but may not influence survival significantly. Therefore the relationship between Apgar scores and survival in term and preterm infants differs. Because of the paucity of studies on preterm infants, we tested Apgar scores, as well as birthweight and gestational age, as outcome predictors in 748 low-birthweight infants (500-1800 gm). Our purpose was to assess the relationship between 1- and 5-minute Apgar scores and survival, and to evaluate all combinations of the four variables as outcome predictors. Univariate analysis showed a significant relationship between each of the four variables and survival; however, no single variable accounted for more than 32% of the variance in outcome, thus no single factor could be invoked as the major determinant of survival. Logistic regression analyses demonstrated the interrelationships of the four variables to survival. While both Apgar scores were related to survival, independent of the effects of birthweight and gestational age, they were slightly less predictive than either of these variables alone. However, when 1- and 5-minute Apgar scores were combined with gestational age, the predictive value was slightly better than any of the four variables alone or in other possible combinations.

Apgar Score↗

PubMed1987

Granulocytic sarcoma: a diagnosis to be considered in unusual lymphoma syndromes.

A series of 7 patients with granulocytic sarcoma is presented to illustrate its varied clinical picture. In particular, this condition may present with features which suggest a non-Hodgkin lymphoma. The diagnosis will only be made if a high index of suspicion is maintained and special histopathological methods are used. Granulocytic sarcoma should be treated like an acute myeloid leukaemia.

Adult↗

PubMed1987

Cardiac depressant and circulatory effects of prostaglandin D2 in developing lambs.

Pulmonary and systemic vascular and cardiac effects of intravenous prostaglandin D2 (PGD2), given at 0.1, 1.0, and 10 micrograms/kg, were measured in chronically instrumented lambs during normoxia and hypoxia at ages 2-3, 9-14, and greater than or equal to 21 days. During normoxia, PGD2 was not a pulmonary vasodilator at low dose and caused mild pulmonary vasoconstrictor changes at 10 micrograms/kg in young lambs; normoxic older lambs had pulmonary vasoconstriction at both 1 microgram/kg and 10 micrograms/kg doses. With hypoxemia, PGD2 caused mild pulmonary vasodilation at all doses in the youngest lambs, converted the normoxic 9-14-day-old lambs' pressor response to a nonresponse, and attenuated the high-dose pulmonary vasoconstriction in the greater than or equal to 21 day lambs. PGD2 was a directly dose-related systemic pressor (+5-20 mmHg) at all ages during both normoxia and hypoxia. Heart rate and cardiac output decreased in a dose-dependent fashion during both normoxia and hypoxia. The PGD2-induced cardiac depression was unaltered by age or ventilatory hypoxemia. PGD2 response of the lamb pulmonary circulation changes from marginal dilation to constriction during the late postnatal development. During the same period, PGD2 dose-related systemic pressor and cardiac depressant effects remain stable. Thus, the circulatory effects of PGD2 are complexly interrelated with age, dose, and presence of hypoxemia.

Animals↗

PubMed1987

Efficient inference for random-coefficient growth curve models with unbalanced data.

Growth and dose-response curve studies often result in incomplete or unbalanced data. Random-effects models together with a variety of computer-intensive iterative techniques have been suggested for the analysis of such data. This paper is concerned with a noniterative method for estimating and comparing location parameters in random-coefficient growth curve models. Consistent and asymptotically efficient estimators of the location parameters are obtained using estimated generalized least squares. Two criteria for testing multivariate general linear hypotheses are introduced and their asymptotic properties are investigated. The results are applied to clinical data obtained on the blood ultrafiltration performance of hemodialyzers used in the treatment of patients with end-stage renal disease.

Biometry↗

PubMed1986

Value of Tru-cut biopsy in the diagnosis of soft tissue tumours.

The light microscopic appearances of Tru-cut needle biopsies from 50 consecutive soft tissue tumours were assessed by three pathologists and compared with the definitive histological diagnosis. Forty-four patients had soft tissue sarcomas and six had benign soft tissue lesions. A correct predictive diagnosis of sarcoma was made on 87-98 per cent of adequate Tru-cut specimens, the accuracy varying between pathologists. Three sources of diagnostic error were recognized: false positive cores (8 per cent), false negative cores (8 per cent), and cores inadequate for diagnosis (16 per cent). The major source of confusion related to difficulties in differentiating infiltrating fibromatosis from malignant fibrous histiocytoma. The high sensitivity of Tru-cut needle biopsy suggests that it could be a valuable aid in the diagnosis of clinically suspected soft tissue sarcomas.

Adolescent↗

PubMed1986

Statistical analysis of statural growth following kidney transplantation.

Factors affecting the growth rates of 59 children and adolescents for the first 2 years following kidney transplantation were evaluated. The factors assessed were age at transplantation, renal function, prednisone dosage, donor source, and prior history of transplantation. The observed growth velocity was expressed as the percentage, of the growth velocity predicted by bone age. Normal growth (greater than or equal to 80%) was exhibited by 37% of the patients and 22% had accelerated growth (greater than or equal to 100%). The chronologic age at transplantation did not correlate significantly with growth when bone age was used as the reference for expected velocity. Males grew better than did females. There was a unique sex/race interaction with black males growing most rapidly. Better renal function, the ability to lower prednisone dosage, alternate day prednisone administration, and a decreasing diastolic blood pressure were positively correlated with better growth rates after transplantation. The donor source and prior history of transplantation did not significantly influence growth rate.

Adolescent↗

PubMed1986

Statistical analysis of statural growth following kidney transplantation.

Factors affecting the growth rates of 59 children and adolescents for the first 2 years following kidney transplantation were evaluated. The factors assessed were age at transplantation, renal function, prednisone dosage, donor source, and prior history of transplantation. The observed growth velocity was expressed as the percentage of the growth velocity predicted by bone age. Normal growth (greater than or equal to 80%) was exhibited by 37% of the patients and 22% had accelerated growth (greater than or equal to 100%). The chronological age at transplantation did not correlate significantly with growth when bone age was used as the reference for expected velocity. Males grew better than did females. There was a unique sex/race interaction with black males growing most rapidly. Better renal function, the ability to lower prednisone dosage, alternate day prednisone, and a decreasing diastolic blood pressure were positively correlated with better growth rates after transplantation. Donor source and prior history of transplantation did not significantly influence growth rate.

Adolescent↗

PubMed1986

Biological studies of ten human squamous carcinoma cell lines: an overview.

Ten cell lines established from surgical specimens of human squamous carcinomas of the tongue and larynx have been investigated with respect to their motility, ultrastructure, karyotypes, certain biochemical features, interaction with normal epithelial and stromal elements and capacity to infiltrate three-dimensional organoid systems. All the cell lines have maintained several morphological and biochemical characteristics indicating a common origin, although the extent to which each line displays this heritage is variable. The phenotypes of each of the individual cell lines are, however, notably stable. Data are provided for epithelial surface markers (including epidermal growth factor, EGF) and for the synthesis and release of prostaglandins and proteases which may be involved in invasive mechanisms. Encounters between the cell lines and organoid substrata (embryonic chick heart spheroids, human amnion, chick chorioallantoic membrane) are described: the results indicate a scale of invasiveness ranging from lack of penetration to full-thickness infiltration by cells showing various distinctive growth patterns. Correlation between in vitro and in vivo findings is discussed, and it is suggested that the biological heterogeneity of the lines may reflect inherent properties of the original carcinoma cell populations which are more distinctly expressed in vitro.

Aged↗

PubMed1986

Prognostic implications of perineural spread in squamous carcinomas of the head and neck.

The occurrence and prognostic implications of perineural spread were examined in 239 patients with mucosal squamous carcinomas of the head and neck. Perineural spread was demonstrated in resections from 64 patients (27%), the majority having primary tumors at one of three sites: buccal cavity, larynx, and pharynx. Perineural spread near nodal metastases was uncommon. There was no evidence that perineural involvement was more commonly associated with large tumors or less differentiated ones. No association was established between perineural spread and coexistent lymph node deposits in the surgical resections. Perineural spread was, however, shown to be a statistically significant prognostic factor for an increased incidence of subsequent locoregional recurrence and for decreased survival.

Adult↗

PubMed1986

Prevention of springboard and platform diving injuries.

Although diving is one of the safer sports, because of the inherent complexity of many maneuvers, injuries can occur. Most of the injuries that a diver sustains are minor, but major and even fatal injuries have occurred. Training under a well qualified and experienced coach is important. Support from parents in terms of encouragement and finance is needed to ensure that the diver receives the best and safest training available. With appropriate facilities and preparation, many of the serious injuries can be prevented.

Athletic Injuries↗

PubMed1986

Prospective pricing system for tertiary neonatal intensive care.

This study assessed the potential impact of the federal neonatal diagnosis-related group (DRG) pricing system upon reimbursement to a state neonatal intensive care program. Data for length of intensive care unit stay, procedures, hospital charges, and audited cost reports from the state of Florida's ten regional neonatal intensive care centers were analyzed for 8,492 neonates whose charges totaled $118 million. Mean lengths of stay in these tertiary care centers were substantially longer than those reported for the federal DRGs, which were based on community hospital data. If federal DRG-based reimbursement to hospitals were implemented in Florida's perinatal intensive care program, compensation would range from 9% to 56% of actual hospital care charges. Federal DRG price rates were not predictive of hospital charges. Only 16% of the total variation in hospital charges was explained by differences among federal DRG rates (R2 = .16). Analysis of data by major determinants of resource consumption provided groups more homogeneous with respect to hospital charges and, hence, cost. Therefore, we developed a prospective pricing system that used modifications of federal newborn DRG system. These modifications resulted in a threefold increase in R2 (.52). Our proposed system permits prediction of cost and reimbursement for infants by three criteria: birth weight, need for mechanical ventilation and/or major surgery, and survival status and length of survival for those who die.

Analysis of Variance↗

PubMed1985

Medical management of intestinal obstruction in patients with advanced malignant disease. A clinical and pathological study.

A clinical and pathological study was made of 40 patients with intestinal obstruction due to far-advanced abdominal and/or pelvic malignant disease. Surgical intervention was feasible in only 2 cases. The remaining 38 patients were managed medically without intravenous fluids and nasogastric suction. Obstructive symptoms such as intestinal colic, vomiting, and diarrhoea were effectively controlled by drugs.

Abdominal Neoplasms↗

PubMed1985

Lysis of type-I collagen by squamous carcinomas of the head and neck.

Lysis of type-I collagen by squamous carcinomas of the head and neck has been studied in freshly excised tissues, xenografts and established cell lines. Investigations with 35 freshly excised tumours showed only low levels of active and total collagenase in both carcinomas and controls. A difference became apparent when the tissues were set up in explant organ culture where a significant (p less than 0.05) increase in total collagenase was found in 13/19 tumours compared with paired control tissues over a 4-week culture period. Two xenografts showed little capacity to lyse collagen in vitro and there was only limited evidence of an increase in total collagenase after explantation and growth in organ culture. Twenty tumour cell lines showed low levels of active collagenase. Total collagenase levels were significantly increased (p less than 0.05) in 4 of the cell lines derived from cancers of the tongue; this activity was sustained in subsequent passages. Six control fibroblastoid cell lines also showed low levels of active collagenase. Levels of total collagenase were consistently high, but this activity was transient and declined in subsequent passages. Co-cultivation experiments with II tumour-cell lines and 5 fibroblastoid cell lines showed some enhanced, synergistic destruction of collagen. Parallel experiments with supernatant media from the carcinoma and fibroblastoid lines showed no enhancement, indicating that intact carcinoma cells and fibroblastoid cells are required for synergistic collagenolysis to take place.

Animals↗

PubMed1985

Immunohistochemical localization of basement membrane type IV collagen in invasive and metastatic squamous carcinomas of the head and neck.

The immunohistochemical localization of basement membrane type IV collagen was investigated with a mouse monoclonal antibody in major surgical resections from 25 patients with invasive squamous carcinomas of the head and neck. Irrespective of site, size or stage of the disease, the 16 primary invasive tumours were almost completely surrounded by a layer of type IV collagen. Focal abnormalities were regularly present, consisting of thickening and aggregation of type IV collagen together with attenuation and segmental loss. Similar changes were seen in metastatic squamous carcinomas in 36 cervical lymph nodes. It is suggested that the probable formation of a normal basement membrane protein by these squamous carcinomas indicates the preservation of a normal function of differentiating squamous epithelia. The results indicate that a major basement membrane component, type IV collagen, continues to co-exist with invasive and metastatic squamous carcinomas.

Adult↗