Does managed care affect the supply and use of ICU services?

This paper analyzes use of hospital intensive care units (ICUs) by adult patients who are under age 65 and not covered by Medicaid; it allows for variation in indicators of the patient's condition, severity of illness, type of admission, emergency status, and degree of constraint on the total hospital ICU supply. We use data for Massachusetts and Florida in 1992. In neither state is there a significant difference in ICU admission rates between managed care patients and other privately insured patients. In Massachusetts, we find that the length of stay in the ICU is somewhat less for managed care and uninsured patients than for other privately insured patients. In both states, a hospital's ratio of total annual supply of ICU services to expected demand has a strong effect. In Massachusetts, the differences across payer groups in length of stay disappear for hospitals where the total ICU supply is relatively constrained.

A comparison of the pharmacological properties of carbohydrate remodeled recombinant and placental-derived beta-glucocerebrosidase: implications for clinical efficacy in treatment of Gaucher disease

The objective of these studies was to characterize the macrophage mannose receptor binding and pharmacological properties of carbohydrate remodeled human placental-derived and recombinant beta-glucocerebrosidase (pGCR and rGCR, respectively). These are similar but not identical molecules that were developed as enzyme replacement therapies for Gaucher disease. Both undergo oligosaccharide remodeling during purification to expose terminal mannose sugar residues. Competitive binding data indicated carbohydrate remodeling improved targeting to mannose receptors over native enzyme by two orders of magnitude. Mannose receptor dissociation constants (Kd) for pGCR and rGCR were each 13 nmol/L. At 37 degrees C, 95% of the total macrophage binding was mannose receptor specific. In vivo, pGCR and rGCR were cleared from circulation by a saturable pathway. The serum half-life (t1/2) was 3 minutes when less than saturable amounts were injected intravenously (IV) into mice. Twenty minutes postdose, beta-glucocerebrosidase activity increased over endogenous levels in all tissues examined. Fifty percent of the injected activity was recovered. Ninety-five percent of recovered activity was in the liver. Parenchymal cells (PC), Kupffer cells (KC), and liver endothelium cells (LEC) were responsible for 75%, 22%, and 3%, respectively, of the hepatocellular uptake of rGCR and for 76%, 11%, and 12%, respectively, of the hepatocellular uptake of pGCR. Both molecules had poor stability in LEC and relatively long terminal half-lives in PC (t1/2 = 2 days) and KC (t1/2 = 3 days).

Nurses counseling patients about smoking cessation--why, when, and how

In patient health education, nurses are a natural choice for on-the-spot counsellors and teachers. Yet many nurses feel uncomfortable about broaching subjects such as smoking cessation with their patients or the patients' families. The authors argue that it is time for nursing programs and hospitals to prepare and encourage nurses to take the initiative in smoking-cessation counseling.

Nocturnal asthma: effect of salmeterol on quality of life and clinical outcomes

OBJECTIVE

To evaluate the effect of salmeterol on asthma-specific quality of life in patients experiencing significant nocturnal symptoms.

DESIGN

Randomized, double-blind, placebo-controlled, multicenter clinical trial.

SETTING

Allergy/respiratory care clinics.

PATIENTS

Nonsmokers > or = 12 years of age with nocturnal asthma symptoms on at least 6 of 14 days during screening and > or = 15% decrease in peak expiratory flow (PEF) from baseline on nocturnal awakening at least once during screening.

INTERVENTIONS

Salmeterol, 42 microg, or placebo twice daily. Patients were allowed to continue theophylline, inhaled corticosteroids, and "as-needed" albuterol.

MEASUREMENTS AND RESULTS

Outcome measures included Asthma Quality of Life Questionnaire (AQLQ) global and individual domain scores, FEV1, PEF, nighttime awakenings, asthma symptoms, and supplemental albuterol use. Mean change from baseline for the global and domain AQLQ scores was significantly greater (p < or = 0.005) with salmeterol compared with placebo. At week 12, salmeterol significantly (p < 0.001 compared with placebo) increased mean change from baseline in FEV1, morning and evening PEF, percentage of symptom-free days, percentage of nights with no awakenings due to asthma, and the percentage of days and nights with no supplemental albuterol use. Significant improvements in PEF were observed after treatment with salmeterol regardless of concomitant treatment with theophylline (p < 0.05).

CONCLUSIONS

These results provide evidence that validates the role of salmeterol in improving quality of life in patients with moderate persistent asthma who exhibited nocturnal asthma symptoms and supports the efficacy of salmeterol compared with that of placebo (ie, "as-needed" albuterol).

Ischemic colitis and sumatriptan use

Sumatriptan succinate, a serotonin-1 (5-hydroxytryptamine-1) receptor agonist, is an antimigraine drug that is reported to act by selectively constricting intracranial arteries. Recently, vasopressor responses that are distinct from the cranial circulation have been demonstrated to occur in the systemic, pulmonary, and coronary circulations. Cases have been published of coronary vasospasm, myocardial ischemia, and myocardial infarction occurring after sumatriptan use. We report on the development of 8 serious cases of ischemic colitis in patients with migraine treated with sumatriptan.

Neuroleptic malignant syndrome in a burn patient

A 39 year old white male with a 55% total body surface burn who developed neuroleptic malignant syndrome (NMS) during his acute course is reported. The patient had several acute sinusitis and septic episodes during his acute course. On postburn day 31, he developed a temperature of 108.4 degrees F (42.4 degrees C). This responded promptly to Dantrolene and Bromocriptene. His recovery was uneventful. NMS is a drug-related response to various medications, such as Haloperidol, which the patient was receiving. NMS must be considered as part of the differential diagnosis of fever in burn patients receiving medication known to cause the syndrome.

Supraglottic and subglottic airway injury due to deployment and rupture of an automobile airbag

A 46-year-old white female with underlying interstitial lung disease and asthma was driving a pickup truck when it was struck broadside. The airbag inflated and then ruptured, forcing inhalation of its contents. This produced facial desquamation, productive cough, wheezing, and headache. Chest radiograph showed bilateral interstitial fibrosis. Pulmonary function tests demonstrated small airway obstruction, hyperinflation, and impaired diffusion. Computerized tomography showed extensive sinusitis. She improved following treatment with inhaled steroids, bronchodilators, and oral antibiotics. Inhalation of the airbag contents produced supraglottic and subglottic airway inflammation, resulting in sinusitis and exacerbation of her underlying asthma.

State variations in Medicare expenditures

OBJECTIVES

This study examined variations in Medicare expenditures across states.

METHODS

1992 data on average Medicare expenditures per enrollee, users of services per 1000 enrollees, service use per user, and payment per unit of service were compared across states for various services. Weighted least squares regression analysis was employed to examine total Medicare expenditures per enrollee by state.

RESULTS

Variation in Medicare expenditures across states is driven more by average number of service users per 1000 enrollees and average service units per user than by average payment per service unit. Medicare expenditures per enrollee by state are primarily a function of Medicare HMO penetration rate (P = .000), urban area (P = .001), hospital bed supply (P = .005), elderly mortality rate (P = .012), Medicare physician assignment rate (P = .026), percentage of primary care practitioners (P = .042), and interactions between urban elderly and percentage of primary care physicians (P = .005) and Black elderly and nursing home bed supply (P = .012).

CONCLUSIONS

Before sweeping Medicare cuts are undertaken or excessive reliance on managed care occurs, attention should be focused on the current disproportionate distribution of expenditures across states.

Trauma-induced striatal CNTF and BDNF mRNA in hemiparkinsonian rats

Surgical implantation of tissues into the brain causes trauma to the region receiving the graft. This study shows that real or simulated striatal trauma in hemiparkinsonian rats leads to increased expression of two trophic factor mRNAs: ciliary neurotrophic factor (CNTF) and brain-derived neurotrophic factor (BDNF). The baseline expression of BDNF mRNA was also markedly lower in dopamine-depleted striatum than in normal striatum in non-traumatized (control) hemiparkinsonian rats. Striatal CNTF message was relatively symmetrical in the non-traumatized (control) hemiparkinsonian rats. Host production of these and other trophic factors may play important roles in the response to tissue grafting, to enhance graft survival and as a stimulus to regenerative collateral axonal sprouting.

Peptide T in the treatment of painful distal neuropathy associated with AIDS: results of a placebo-controlled trial. The Peptide T Neuropathy Study Group

OBJECTIVE

To assess the safety and efficacy of Peptide T in the treatment of painful distal symmetrical polyneuropathy (DSP) associated with human immunodeficiency virus (HIV) infection.

BACKGROUND

Painful DSP is a frequent complication of HIV infection, although its etiology and optimal treatment are unknown. Peptide T (D-(alpha 1)-Peptide T-amide) has been found in phase I trials and anecdotal reports to relieve neuropathic pain in AIDS patients.

DESIGN/METHODS

In this multicentered, double-blind, randomized study, subjects received intranasal Peptide T 6 mg/day or placebo for 12 weeks. The primary outcome measure was change in the modified Gracely pain score. Secondary efficacy variables were results of neurologic examination, neuropsychological and electrophysiologic studies, global evaluation, and CD4 lymphocyte counts.

RESULTS

Of 81 evaluable subjects, 40 received Peptide T and 41 received placebo. The change in pain scores was not significantly different (p = 0.32) in the Peptide T group (-0.24) as compared to placebo (-0.39). Group comparisons were not significantly different for change in any clinical examination or neuropsychologic measure, sural nerve amplitude or conduction velocity, or CD4 lymphocyte count. No significant drug-related adverse effects occurred in either group.

CONCLUSION

Intranasal Peptide T is safe but ineffective in the treatment of painful DSP associated with AIDS.

Swallow function in children with Down syndrome: a retrospective study

The swallow behavior of 19 children with Down syndrome was reviewed. Findings suggest their oral phase may be impacted by oral hypersensitivity which can interfere with their acceptance of textured foods. A disordered pharyngeal phase was identified in 16 of the children, with aspiration occurring in 10 of the 19 children studied. Aspiration identified was silent for eight of these 10 children with cough data and did not correlate with the severity of their oral phase. Aspiration was, therefore, felt to warrant consideration as a factor in the respiratory illness so often seen in this population.

Interleukin-1 mediates increased plasma levels of eicosanoids and cytokines in patients with sepsis syndrome

The purpose of this was to study evaluate the effects of interleukin-1 (IL-1) inhibition by human recombinant IL-1 receptor antagonist (IL-1ra) on plasma prostaglandin, leukotriene, and cytokine levels in sepsis syndrome. As part of a multisite, prospective, randomized, double-blind, placebo-controlled clinical trial, 19 septic patients received IL-1ra in a 100 mg bolus followed by 2.0 mg/kg/h i.v. for 72 h (n = 10) or placebo (n = 9). Plasma thromboxane B2 (TXB2), prostaglandin 6-keto-F1 alpha (PGI), leukotriene B4 (LTB4), leukotrienes C4D4E4 (LTC4D4E4), IL-1 beta, IL-6, and tumor necrosis factor alpha (TNF) were measured by ELISA before study drug infusion (baseline) and at 24, 48, 72, and 96 h after the beginning of the study drug infusion. Differences between placebo and IL-1-ra for plasma LTB4 and TNF were not significant. Plasma TXB2, PGI, LTC4D4E4, and IL-6, expressed as % baseline, were significantly lower in patients receiving IL-1ra than in the placebo group (p < .05), while plasma IL-1 was increased significantly. IL-1 may be a necessary mediator of increased circulating PGI, TXB2, LTC4D4E4, and IL-6 levels in patients with sepsis syndrome. Plasma IL-1 is increased with infusion of IL-1ra. The clinical significance of IL-1 in modifying circulating eicosanoid and cytokine concentrations in clinical sepsis is not clear from the data.

Mice lacking the CNTF receptor, unlike mice lacking CNTF, exhibit profound motor neuron deficits at birth

Ciliary neurotrophic factor (CNTF) supports motor neuron survival in vitro and in mouse models of motor neuron degeneration and was considered a candidate for the muscle-derived neurotrophic activity that regulates motor neuron survival during development. However, CNTF expression is very low in the embryo, and CNTF gene mutations in mice or human do not result in notable abnormalities of the developing nervous system. We have generated and directly compared mice containing null mutations in the genes encoding CNTF or its receptor (CNTFR alpha). Unlike mice lacking CNTF, mice lacking CNTFR alpha die perinatally and display severe motor neuron deficits. Thus, CNTFR alpha is critical for the developing nervous system, most likely by serving as a receptor for a second, developmentally important, CNTF-like ligand.

Strategic responses by hospitals to increased financial risk in the 1980s

OBJECTIVE

This research addresses the following types of responses by hospitals to increased financial risk: (a) increases in prices to privately insured patients (testing separately the effects of risk from the effects of "cost-shifting" that depends on level of Medicare payment in relation to case mix-adjusted cost); (b) changes in service mix offered and selectivity in acceptance of patients to reduce risk; and (c) efforts to reduce variation in resource use for those patients admitted.

DATA SOURCES

The database includes a national panel of over 400 hospitals providing information from patient discharge abstracts, hospital financial reports, and county level information over the period 1980-1987.

STUDY DESIGN

Econometric methods suitable to panel data are implemented, with tests for pooling, hospital-specific fixed effects, and possible problems of selection bias.

PRINCIPAL FINDINGS

The prices paid by private insurers to a particular hospital were affected by the changes in risk imposed by Medicare prospective payment, the generosity of Medicare payment, state rate regulation, and ability of the hospital to bear risk. The risk-weighted measure of case mix did not respond to changes in payment policy, but other variables reflecting the management of care after admission to reduce risk did change in the predicted directions.

CONCLUSIONS

Some of the findings in this article are relevant to current Medicare policies that involve risk-sharing, for instance, special allowances for "outlier" patients with unusually high cost, and for sole community hospitals. The first type of allowance appears successful in preserving access to care, while the second type is not well justified by the findings. State rate regulation programs were associated not only with lower hospital prices but also with less risk reduction behavior by hospitals. The design of regulation as a sort of risk-pooling arrangement across payers and hospitals may be attractive to hospitals and help explain their support for regulation is some states.

The changing distribution of a major surgical procedure across hospitals: were supply shifts and disequilibrium important?

This paper describes and analyzes the changing distribution across hospitals in the U.S. of total hip replacement surgery (THR) for the period 1980-1987. THR is one of the most costly single procedures contributing to health care expenses. Also, the use of THR exhibits a particularly high degree of geographic variation. Recent research pointed to shifts in demand as one plausible economic explanation for increasing use of THR. This paper questions whether shifts in supply may have been large enough to explain changes in patient mix and the relationship of patient mix to the number of procedures performed at a particular hospital. In addition, the relationship between total use of THR and the local availability of orthopaedic surgeons as well as the average allowable Medicare fee for standardized physician services is analyzed. These relationships might yield evidence to support a scenario of induced demand beyond the optimum for patients' welfare, or evidence of supply increase within a disequilibrium scenario. This study, using data for all THR patients in a large sample of hospitals, tends to reject the formulation of a market with independent supply and demand shifts where the supply shifts were the dominant forces. Hospitals with a larger number of THRs performed did not see a higher percentage of older, sicker, and lower income patients. It was more likely that demand shifts generated increases in capacity for surgical services. Moreover, there was little evidence for a persistent disequilibrium and only weak evidence for inducement. Also, we found little evidence that hospitals responded to financial incentives inherent in the Medicare payment system after 1983 to select among THR candidates in favour of those with below average expected cost. We did observe increased concentration over time of THR procedures in facilities with high volume--suggesting plausible demand shifts towards hospitals with a priori quality and cost advantages or who obtained those advantages with a high volume of patients.

BDNF and NT-4/5 exert neurotrophic influences on injured adult spinal motor neurons

Adult motor neurons, like their immature antecedents, express the mRNA for the signaling receptor for brain-derived neurotrophic factor (BDNF) and for neurotrophin-4/5 (NT-4/5). However, while both BDNF and NT-4/5 support the survival of axotomized developing spinal motor neurons in vitro or in vivo, it is not known whether these factors continue to influence spinal motor neurons in adulthood. The present study tests if BDNF or NT-4/5 modulate the reactive responses of adult spinal motor neurons to nerve injury. We utilize sciatic nerve transection to axotomize the spinal motor neurons that form the retrodorsal lateral nucleus (RDLN) and show that, after axotomy, RDLN motor neurons lose ChAT immunoreactivity and also reexpress p75Ingfr, the low affinity receptor for all neurotrophin family members. Treatment with BDNF or NT-4/5 alters these effects of sciatic nerve transection. Both BDNF and NT-4/5 attenuate the loss of ChAT expression in axotomized RDLN motor neurons; thus, as compared to vehicle treatments, BDNF and NT-4/5 produce statistically significant increases in the optical density of ChAT immunostaining. Furthermore, BDNF and NT-4/5 also significantly increase the RDLN reexpression of p75Ingfr after sciatic nerve transection. Interestingly, essentially identical increases in RDLN ChAT and p75Ingfr immunostaining are produced by sciatic nerve crush injuries in the absence of exogenous neurotrophin treatment. These data show that treatment with exogenous BDNF and NT-4/5 changes the response of adult spinal motor neurons to sciatic nerve transection. Furthermore, these neurotrophins elicit reactive responses in axotomized motor neurons that mimic those produced by endogenous agents in regenerating crushed peripheral nerve.

Impacts of hospital budget limits in Rochester, New York

During 1980-87, eight hospitals in the Rochester, New York area participated in an experimental program to limit total revenue. This article analyzes: increase of costs for Rochester hospitals; trends for inputs and compensation; and cash flow margins. Real expense per case grew annually by about 3 percent less in Rochester. However, after 1984, Medicare prospective payment had an effect of similar size outside Rochester. Some capital inputs to hospital care were restrained, as were wages and particularly benefits. The program did not generally raise or stabilize hospital revenue margins, while the ratio of cash flow to debt trended down. Financial stringency of this program relative to alternatives may have contributed to its end.

Pharmacokinetics and pharmacodynamics of multiple oral doses of MK-0591, a 5-lipoxygenase-activating protein inhibitor

The pharmacodynamics, kinetics, and tolerability of a new orally active 5-lipoxygenase inhibitor were evaluated in healthy male volunteers. MK-0591, 50, 125, and 250 mg every morning and 250 mg every 12 hours, was administered for 10 days. Leukotriene B4 biosynthesis ex vivo in ionophore (A23187)-stimulated whole blood and leukotriene E4 levels in urine were determined. Leukotriene B4 production was inhibited up to 90% of baseline for 12 hours after administration at the highest dose. The degree of leukotriene B4 inhibition ex vivo in whole blood significantly correlated with plasma MK-0591 concentrations (0 to 1500 ng/ml; r = 0.73). Urinary leukotriene E4 was inhibited by > 80% at 24 hours after administration for all dose levels. Pharmacokinetics of MK-0591 were linear, with a half-life of approximately 6 hours. Very little accumulation was seen after multiple dosing. MK-0591 had no effect on testosterone levels, and good tolerability was shown at all dose levels of MK-0591 administered for up to 10 days.

Femoral venous catheters: a safe alternative for delivering parenteral alimentation

Femoral vein catheterization is an alternative method of obtaining central venous access. Placement of femoral venous catheters (FVCs) is possible in the majority of patients, suitable for most indications, and associated with a low complication rate during insertion. We wished to determine the incidence of infections or other complications resulting when parenteral nutrition was delivered through FVCs. Fifty-two patients were followed from a hospital-wide population including patients in the critical care units. Triple-lumen catheters were placed by using the sterile Seldinger technique, and sites were examined daily for inflammation. Bacteriologic surveillance was accomplished by submitting the catheter tip for semiquantitative cultures. If catheter line sepsis was suspected, blood samples for cultures were drawn through the catheter and peripherally. The rate of occurrence of colonized catheters was 9.6% (five of 52), and catheter sepsis was found in one case (1.9%). Other than inflammation at six (11.5%) of 52 catheter sites, noninfectious complications of FVCs were not found. On the basis of these findings, we consider FVC-delivered parenteral alimentation a safe and effective alternative to other forms of central venous access.

Malignant thymoma. A complicated triad of SVC syndrome, cardiac tamponade, and DIC

A patient presented with multisystem disease due to a very aggressive malignant thymoma. The case was complicated by the triad of cardiac tamponade, superior vena cava (SVC) syndrome, and disseminated intravascular coagulation (DIC). A review of the English literature reveals this to be a unique constellation of clinical symptoms and that DIC was heretofore unreported.

Access to heart and liver transplantation in the late 1980s

Because of a shortage of usable organs, many who require heart or liver transplants for survival will not have access to them. Access to care may reflect demographic factors and ability to pay, as well as medical considerations. Receipt of an organ may be influenced by expected survival with and without a transplant, age, gender, race, ability to pay, and distance to a transplant center. Discharge abstract data from a national sample of over 500 hospitals in 1986 and 1987 were used to select heart and liver recipients and others with end-stage diseases who did not receive a transplant. Multivariate logistic regression analyses were then used to estimate how receipt of a transplant was influenced by expected years of survival after transplantation (YAT), expected ability to pay, age, sex, race, and distance to a transplant center. Controlling for differences in expected YAT, age, sex, race, and distance to the transplant center, those expected to have the most ability to pay were more likely to receive heart and liver transplants, compared to those expected to have medium ability to pay. Third-party coverage was particularly important in receipt of a transplant for those with absolute contraindications. Expected YAT and age were significant, with some evidence of a tradeoff between urgency and expected YAT in the case of hearts. Men were more likely to obtain heart transplants and women were more likely to get liver transplants. The effects of distance were small. Existing regulatory incentives and biological, medical, and cultural reasons may justify the age-, sex-, race-, and prognosis-related differences in the odds of receiving a transplant. The importance of ability to pay may not have been adequately observed in previous studies restricted to the patients screened at major transplant centers. Hospital discharge records with personal identifiers, linkage to official waiting lists, and better patient level socioeconomic information would permit more definitive analysis.

HMO medical directors' perceptions of geriatric practice in Medicare HMOs

OBJECTIVE

To determine the extent to which health maintenance organizations (HMOs) with Medicare risk contracts utilize geriatricians and selected aspects of "organized" geriatric practice.

DESIGN

A telephone interview survey.

PARTICIPANTS

Eighty-two percent (64 of 78) of the HMOs with Medicare risk contracts as of June 1991.

MEASUREMENTS

Questions to medical directors of the Medicare HMOs on (1) the presence of geriatricians, (2) the roles of geriatricians, and (3) "organized" geriatric practice.

MAIN RESULTS

Fifty-three percent of the Medicare HMOs have one or more geriatricians, but only 19% have attempted to recruit geriatricians. Geriatricians provide primary care in 76% of the HMOs with geriatricians and serve as specialist consultants in 61%. Geriatricians are reported to be used actively in 32% of the HMOs that have them. The proportion of HMOs utilizing "organized" geriatric activities ranges from a high of 58% for a general health information questionnaire to a low of 12% for a special form(s) for comprehensive geriatric assessment. While the percentage of HMOs using each of the "organized" strategies is higher for the HMOs with geriatricians than for those without, this is statistically significant for only one strategy--the use of special approaches or formal protocols for problems frequently found in the elderly (P = 0.04).

CONCLUSIONS

The perception of Medicare HMO medical directors is that about half of the HMOs utilize geriatricians and that there is evidence of "organized" geriatric practice. However, it appears that geriatricians and many of the elements of organized geriatric practice are used to a much lesser extent than experts recommend. Medicare HMOs must themselves test the various components of organized geriatric practice in order to determine their utility.

Increased use of an expensive, elective procedure: total hip replacements in the 1980s

Between 1980 and 1987, the number of hospital discharges with total hip replacement (THR) increased by more than 90%, while total hospital discharges fell by more than 10%. Total hip replacement is one of the most costly hospital inpatient procedures, both per case and in total Medicare expenses. Explanations for the growth in use of THR may clarify some of the major forces driving national health care costs. This study assumes that treatment choices are made by (or for) each patient to maximize expected net benefits. Within this framework, the use of THR might have increased because of improved safety for the procedure, longer life expectancy and better control of many serious illnesses that led to increased demand for quality-enhancing procedures, and increased out-of-pocket cost for alternative treatments that are not covered well by insurance. These possible explanations imply changes in the characteristics of THR recipients over time. An upward shift was found in the age distribution of patients, more than simply because of an aging of the population. Sharply increased proportions of patients were also found with serious comorbidities such as cancer and dementia. The safety of the procedure seems to have improved, in terms of the death rate in the hospital. The results suggest that demands for expensive, elective procedures have been increasing for patients previously regarded as too old or impaired to benefit sufficiently. This process leads to continuing increases in real health care expenses even without the invention of new technologies.

Mitral valve area calculations immediately after percutaneous balloon mitral valvuloplasty: effect of the atrial septal defect

OBJECTIVES

The aim of this study was to assess the effect of the atrial septal defect on mitral valve area calculations after balloon mitral valvuloplasty.

BACKGROUND

There is poor correlation between the hemodynamic-derived and Doppler mitral valve area immediately after mitral valvuloplasty. The reasons for this are unclear.

METHODS

Twenty-five patients with severe mitral stenosis were studied. After balloon mitral valvuloplasty, serial mitral valve area calculations were performed with 1) the mitral dilating catheter across the atrial septum, 2) the 7F catheter across the atrial septum, and 3) with the atrial puncture site occluded with the balloon catheter.

RESULTS

The mitral valve area determined by the Gorlin formula with balloon occlusion of the atrial septum was smaller than the mitral valve area determined without balloon occlusion (mean +/- SD 1.8 +/- 0.43 vs. 2.24 +/- 0.67 cm2, p < 0.005 for the mitral dilating catheter across the atrial septum and 1.8 +/- 0.43 vs. 2.19 +/- 0.52, p < 0.05 for the 7F catheter across the atrial septum). The mean of the differences between the mitral valve area derived by the Gorlin formula and by the Doppler pressure half-time method was smaller with the atrial septum occluded than when the dilating catheter or the 7F catheter was across the atrial septum (0.12 +/- 0.26 vs. 0.56 +/- 0.48 cm2 [p < 0.005] and 0.12 +/- 0.26 vs. 0.48 +/- 0.55 cm2 [p < 0.05]). Left to right shunting was detected less frequently by oximetry (60%), than by shunt ratios calculated by using the cardiac output measurements with and without balloon occlusion of the atrial septum (84%).

CONCLUSIONS

The presence of left to right shunts after mitral valvuloplasty may account for some of the discrepancies between mitral valve area found at cardiac catheterization and that by the Doppler pressure half-time method; thus, the latter method may be reliably used to follow up patients in the long term.

Biochemical activity, pharmacokinetics, and tolerability of MK-886, a leukotriene biosynthesis inhibitor, in humans

MK-886, a leukotriene biosynthesis inhibitor, was evaluated in double-blind, placebo-controlled, randomized single- and multiple-dose studies in 12 and 24 healthy male subjects, respectively. The effects of a single dose (250, 500, and 750 mg) and multiple doses (100 mg and 250 mg every 8 hours) of MK-886 on calcium ionophore stimulated leukotriene B4 synthesis ex vivo in whole blood were evaluated. Inhibition of leukotriene B4 biosynthesis ex vivo occurred in a dose-related manner up to a 500 mg single dose, and 250 mg every 8 hours. A single dose of 500 mg MK-886 significantly inhibited leukotriene B4 biosynthesis by a maximum of 60% at 2 hours after the dose (p < 0.05). Multiple doses of 250 mg significantly inhibited leukotriene B4 biosynthesis by a maximum of 52% at 2 hours after the dose (p < 0.05). The degree of leukotriene B4 inhibition ex vivo in whole blood significantly correlated with plasma MK-886 concentrations (r = 0.78). In conclusion, the single and multiple doses of MK-886 evaluated in this study were well tolerated overall and partially inhibited leukotriene B4 biosynthesis ex vivo in whole blood.

Appearance of granulocyte-macrophage colony-stimulating factor activity at allergen-challenged cutaneous late-phase reaction sites

The cytokines IL-3 and granulocyte-macrophage CSF (GM-CSF) activate and/or prime monocytes, basophils, and eosinophils for a number of proinflammatory events in vitro. It was hypothesized that IL-3 and GM-CSF might also participate in the local inflammatory cascades that occur at cutaneous blister sites after Ag challenge in vivo. The M-07e megakaryocytic leukemia cell line, which proliferates in response to IL-3 or GM-CSF, was used to determine whether these cytokines were present in fluids derived after Ag challenge in the cutaneous blister chamber model. Fluids from blister chambers after either Ag (timothy grass, orchard grass, or ragweed) or vehicle control challenge were collected hourly for 12 h from nine patients with allergic rhinitis. Cytokine (IL-3/GM-CSF) activity was modestly elevated at 4 h after Ag challenge compared to control with the median of maximal proliferation 4% (range, 2 to 22%) vs 2% (range, 1 to 14%), respectively (Ag vs control, p &lt; 0.03). Activity peaked at 7 h (Ag = 10%, range 1 to 12%, vs control = 1%, range 1 to 9%, p &lt; 0.02) and then steadily declined. No increase in cytokine activity over control was seen in Ag-challenged nonatopics (n = 5, p = NS), indicating that release did not result from a nonspecific effect of the Ag solution. Neutralization of cytokine bioactivity in pooled late phase reaction (LPR) fluids from h 4 to 12 (n = 5) with anti-IL-3, anti-GM-CSF, or both antisera revealed that the majority of the activity was GM-CSF. To better quantify cytokine levels, pooled LPR fluids prepared from an additional 11 subjects were concentration-dialyzed (10x) and tested for cytokine activity. Pooled fluids from Ag-challenged sites contained a median of 625 pg/ml (range, 30 to 1250 pg/ml) GM-CSF equivalents, whereas those from the vehicle control-challenged sites contained a median 30 pg/ml (range, 30 to 300 pg/ml) GM-CSF equivalents (p &lt; 0.004 Ag vs control groups, n = 11). Concentrated fluid from Ag- and control-challenged sites in two nonatopic subjects contained &lt; 10 pg/ml cytokine activity. To evaluate the IL-3 and GM-CSF activity with a separate technique, ELISA were performed on separately pooled blister fluids from six atopic subjects. Although no IL-3 activity was detected after Ag challenge in these six subjects, all of them demonstrated levels of GM-CSF at Ag-challenged sites comparable to that found in the bioassay.(ABSTRACT TRUNCATED AT 400 WORDS)

Appearance of granulocyte-macrophage colony-stimulating factor activity at allergen-challenged cutaneous late-phase reaction sites

The cytokines IL-3 and granulocyte-macrophage CSF (GM-CSF) activate and/or prime monocytes, basophils, and eosinophils for a number of proinflammatory events in vitro. It was hypothesized that IL-3 and GM-CSF might also participate in the local inflammatory cascades that occur at cutaneous blister sites after Ag challenge in vivo. The M-07e megakaryocytic leukemia cell line, which proliferates in response to IL-3 or GM-CSF, was used to determine whether these cytokines were present in fluids derived after Ag challenge in the cutaneous blister chamber model. Fluids from blister chambers after either Ag (timothy grass, orchard grass, or ragweed) or vehicle control challenge were collected hourly for 12 h from nine patients with allergic rhinitis. Cytokine (IL-3/GM-CSF) activity was modestly elevated at 4 h after Ag challenge compared to control with the median of maximal proliferation 4% (range, 2 to 22%) vs 2% (range, 1 to 14%), respectively (Ag vs control, p < 0.03). Activity peaked at 7 h (Ag = 10%, range 1 to 12%, vs control = 1%, range 1 to 9%, p < 0.02) and then steadily declined. No increase in cytokine activity over control was seen in Ag-challenged nonatopics (n = 5, p = NS), indicating that release did not result from a nonspecific effect of the Ag solution. Neutralization of cytokine bioactivity in pooled late phase reaction (LPR) fluids from h 4 to 12 (n = 5) with anti-IL-3, anti-GM-CSF, or both antisera revealed that the majority of the activity was GM-CSF. To better quantify cytokine levels, pooled LPR fluids prepared from an additional 11 subjects were concentration-dialyzed (10x) and tested for cytokine activity. Pooled fluids from Ag-challenged sites contained a median of 625 pg/ml (range, 30 to 1250 pg/ml) GM-CSF equivalents, whereas those from the vehicle control-challenged sites contained a median 30 pg/ml (range, 30 to 300 pg/ml) GM-CSF equivalents (p < 0.004 Ag vs control groups, n = 11). Concentrated fluid from Ag- and control-challenged sites in two nonatopic subjects contained < 10 pg/ml cytokine activity. To evaluate the IL-3 and GM-CSF activity with a separate technique, ELISA were performed on separately pooled blister fluids from six atopic subjects. Although no IL-3 activity was detected after Ag challenge in these six subjects, all of them demonstrated levels of GM-CSF at Ag-challenged sites comparable to that found in the bioassay.(ABSTRACT TRUNCATED AT 400 WORDS)

Hospitals with chronic financial losses: what came next?

Hospitals with chronic losses might respond by closing, by drastically changing their services and patient mix, or by increasing efficiency. These possible responses are examined by studying a cohort of hospitals that were losing money between 1980 and 1984 as measured by their five-year average total revenue margins. These "negative-cohort" hospitals were followed through 1988 to see if they survived, and if they did, what changes they made. Only about 10 percent of hospitals in the negative cohort closed. The remainder did not alter their service mix or select in favor of easier, better-paying patients. However, there was a reduced rate of investment in new technologies.

The alpha component of the CNTF receptor is required for signaling and defines potential CNTF targets in the adult and during development

We recently proposed that ciliary neurotrophic factor (CNTF) shares two receptor components with a generally acting cytokine, leukemia inhibitory factor (LIF), but that CNTF also requires a third receptor component (CNTFR alpha) that is mostly restricted to the nervous system in its expression. Here we demonstrate that a transfected CNTFR alpha gene is sufficient to confer CNTF responsiveness upon hemopoietic cells normally responsive only to LIF, providing evidence that CNTFR alpha is a required receptor component that uniquely characterizes CNTF-responding cells. Consistent with this notion, CNTFR alpha expression could be localized to neurons within all known peripheral targets of CNTF. CNTFR alpha was also widely expressed within neurons of the CNS, suggesting that CNTF has broader CNS actions than previously appreciated. However, in vivo localization of CNTFR alpha, as well as of CNTF itself, is consistent with a particularly important role for CNTF in motor function as well as during neuropoiesis.

Production of granulocyte/macrophage colony-stimulating factor in human airways during allergen-induced late-phase reactions in atopic subjects

Granulocyte-macrophage colony-stimulating factor (GM-CSF) and interleukin-3 (IL-3) are hematopoietic growth factors that have been shown to induce proliferation and activation of inflammatory cells, and may play a role in allergic reactions. Since little is known about the involvement of cytokines in allergic inflammation in the lung, the levels of GM-CSF and IL-3 were measured in bronchoalveolar lavage (BAL) fluids obtained in the late phase after segmental lung antigen (Ag) challenge in 14 allergic rhinitis subjects with or without bronchial asthma. BAL fluids either after Ag (ragweed, dust mite, or timothy) or saline control challenge were recovered 19 h later. In 6 of the 14 patients, BAL fluids were concentration-dialyzed (20x) and assayed for cytokine activity. Cytokine assays were performed using the human megakaryocytic leukemic cell line M-07e, which is responsive to either GM-CSF or IL-3. The level of GM-CSF-equivalents was approximately 25 times higher in Ag-challenged sites (49.9 +/- 12.7 pg/ml; mean +/- SEM), compared to saline challenge sites (2.2 +/- 1.0, p < 0.01, n = 9). Neutralization experiments using a polyclonal specific antibody (Ab) against GM-CSF and IL-3 revealed that the bulk of the activity was GM-CSF. BAL fluids from Ag- and saline-challenged sites in one nonatopic subject contained no significant GM-CSF activity. Furthermore, the level of GM-CSF in Ag-challenged BAL fluid and the percentage of eosinophils in BAL from each subject correlated significantly (r = 0.73, p < 0.005, n = 14).(ABSTRACT TRUNCATED AT 250 WORDS)

Regulation of ciliary neurotrophic factor expression in myelin-related Schwann cells in vivo

Adult rat sciatic nerve is known to express high levels of ciliary neurotrophic factor (CNTF) mRNA and protein. Here we examine the cellular localization of CNTF protein and mRNA in peripheral nerve and the regulation of CNTF expression by peripheral axons. In intact nerve, CNTF immunoreactivity is found predominantly in the cytoplasm of myelin-related Schwann cells. After axotomy, CNTF immunoreactivity and mRNA levels fall dramatically and do not recover unless axons regenerate. This behavior is similar to the pattern of myelin gene expression in these nerves. We conclude that the expression of CNTF in Schwann cells depends on axon-Schwann cell interactions.

Bronchodilator properties of an inhaled leukotriene D4 antagonist (verlukast--MK-0679) in asthmatic patients

The safety, tolerability and bronchodilator properties of inhaled verlukast (MK-0679), a new potent and selective LTD4-receptor antagonist, were studied in 12 asthmatic subjects with more than 15% increase in FEV1 after salbutamol inhalation. On three separate study days the patients inhaled placebo, verlukast 2 mg and verlukast 8 mg from a metered dose inhaler according to a randomized, double-blind, cross-over allocation schedule. Pulmonary function and tolerability were assessed regularly and after 8 h a second dose of test drug was inhaled. Thirty minutes later a beta 2-agonist dose-response curve was performed by inhaling salbutamol in cumulative doses of 200, 400 and 800 micrograms. Verlukast (8 mg) caused significant improvement in mean FEV1 from 1.5 through 8 h after inhalation as compared to placebo (P less than 0.05). The maximum change in FEV1 occurred at 2 h after inhalation with mean percent increases above baseline of 3.5, 7.7, and 9.2% after placebo, verlukast 2 mg and 8 mg, respectively. The bronchodilator response to inhaled salbutamol was significantly larger after verlukast 8 mg than after placebo pretreatment (P less than 0.05), whereas verlukast 2 mg afforded no additive bronchodilator effect. We conclude that inhalation of the LTD4-antagonist verlukast induces modest but significant bronchodilatation and may be beneficial in the treatment of asthma.

The neurotrophins BDNF, NT-3, and NGF display distinct patterns of retrograde axonal transport in peripheral and central neurons

The pattern of retrograde axonal transport of the target-derived neurotrophic molecule, nerve growth factor (NGF), correlates with its trophic actions in adult neurons. We have determined that the NGF-related neurotrophins, brain-derived neurotrophic factor (BDNF) and neurotrophin-3 (NT-3), are also retrogradely transported by distinct populations of peripheral and central nervous system neurons in the adult. All three 125I-labeled neurotrophins are retrogradely transported to sites previously shown to contain neurotrophin-responsive neurons as assessed in vitro, such as dorsal root ganglion and basal forebrain neurons. The patterns of transport also indicate the existence of neuronal populations that selectively transport NT-3 and/or BDNF, but not NGF, such as spinal cord motor neurons, neurons in the entorhinal cortex, thalamus, and neurons within the hippocampus itself. Our observations suggest that neurotrophins are transported by overlapping as well as distinct populations of neurons when injected into a given target field. Retrograde transport may thus be predictive of neuronal types selectively responsive to either BDNF or NT-3 in the adult, as first demonstrated for NGF.