Health expenditures in major industrialized countries, 1960-87

In this article, levels and changes in health care expenditures for Canada, France, the Federal Republic of Germany, Italy, Japan, the United Kingdom, and the United States are analyzed. First, the levels and changes in the share of gross domestic product (GDP) devoted to health are reviewed in terms of the health-to-GDP ratio, nominal health expenditure and GDP growth, and changes in population and prices. Second, absolute levels of health spending denominated in U.S. dollars are compared over time. Finally, some concluding observations are made.     

Somatotopic gradients in the distributed organization of the human primary motor cortex hand area: evidence from small infarcts

 Nine cases of relatively selective hand weakness produced by stroke were analyzed to examine the degree to which representations of different fingers are segregated in the human primary motor cortex (M1). In five cases, all the digits were involved uniformly; in four cases the radial versus ulnar digits of the hand were involved differentially. No patient showed discrete involvement of a single digit, nor did any patient have greatest weakness in the index, middle or ring finger. These findings provide little evidence that each digit is represented in a separate cortical territory, but rather suggest that broadly overlapping gradients – with the radial digits somewhat more heavily represented laterally and the ulnar digits somewhat more heavily represented medially – are superimposed on an underlying organization in which control of each finger is distributed widely throughout the human M1 hand area. Received: 3 August 1998 / Accepted: 7 January 1999     

Electromyographic evidence of two functional subdivisions in the rhesus monkey's flexor digitorum profundus

The main belly of the macaque's flexor digitorum profundus (FDP) is divided by a dissectible plane into radial and ulnar regions. The present report describes three findings which suggest that the radial and ulnar regions represent separate functional subdivisions of the FDP. First, electromyographic (EMG) recordings during individuated finger movements performed by rhesus monkeys demonstrated different patterns of activation in the radial versus the ulnar region of the FDP. Second, studies of single motor units discriminated from the parent EMG activity also suggested at least two differentially activated motoneuronal pools in the radial versus ulnar region. Third, the finger movements evoked by intramuscular stimulation, delivered through the recording electrodes, indicated that contraction of the radial versus ulnar region produces different patterns of tension on the finger tendons. Together these findings suggest that the radial and ulnar regions of the FDP provide differential tension on the finger tendons to individuate finger movements.     

Immunoassay-based measurement of clinical biomarkers for monitoring changes in nasal cavity

Background

Many drugs for treatment of allergies, migraine headaches, inflammation, and other indications are administered into the nasal cavity providing access to the immune and central nervous systems. One of the concerns for using this route of administration is potential damage to the nasal epithelium and mucosal regions. We assembled a panel of clinical biomarkers that can be used to monitor changes in the nasal epithelium, mucosa, and olfactory regions in preparation for clinical trials involving drugs administered via intranasal route. These biomarkers included albumin, elastase, IL-6, IL-8, lactoferrin, myeloperoxidase and nerve growth factor.

Methods

Immunoassays were developed and used to measure changes in these biomarkers in nasal lavage samples collected twice daily from 30 assumed-healthy volunteers over a 2-day period. Various statistical methods including analysis of variance (ANOVA), paired t-test and Pearson's product–moment correlation were used to evaluate the data.

Results

Although the basal levels of these biomarkers were varied among subjects, the data show that the concentrations of albumin, elastase and IL-8 were significantly higher in samples collected in the morning compared to samples collected later during the day. Pre-washing nasal cavity prior to collecting nasal lavage samples did alter the measurement of elastase and albumin, but did not influence the levels of the other biomarkers.

Conclusions

These data show that this panel of biomarkers can be used to monitor changes in the nasal cavity including those affected by diurnal fluctuations. These results also provide useful baseline values and sources of variability for each biomarker that could be used to help design clinical trials.     

Selectivity of voluntary finger flexion during ischemic nerve block of the hand

During ischemic nerve block of an extremity the cortical representations of muscles proximal to the block are known to expand, increasing the overlap of different muscle representations. Such reorganization mimics that seen in actual amputees. We investigated whether such changes degrade voluntary control of muscles proximal to the block. Nine subjects produced brief, isometric flexion force selectively with each fingertip before, during, and after ischemic block at the wrist. We recorded the isometric force exerted at the distal phalanx of each digit, along with electromyographic (EMG) activity from intrinsic and extrinsic finger muscles. Despite paralysis of the intrinsic hand muscles, and associated decrements in the flexion forces exerted by the thumb, index, and little fingers, the selectivity of voluntary finger flexion forces and of EMG activity in the extrinsic finger muscles that generated these forces remained unchanged. Our observations indicate that during ischemic nerve block reorganization does not eliminate or degrade motor representations of the temporarily deafferented and paralyzed fingers.     

Accuracy of expiratory carbon dioxide measurements using the coaxial and circle breathing circuits in small subjects

Mass spcctrometry is widely used to measure the end-tidal concentrations of inhalation anesthetics and other gases during surgery in order to estimate their arterial concentrations. When certain breathing circuits are used in newborns, however, fresh gas or ambient air may contaminate the expired sample, introducing a systematic error in the measurement of any end-tidal gas concentration. We estimated this error in newborn piglets using carbon dioxide as an indicator substance of expired gas. The capnograms and the difference between arterial carbon dioxide tension (PaCO₂) and peakexpired carbon dioxide tension (PeCO₂) were compared when either a coaxial (Bain) or circle breathing circuit was used. Gas was sampled from the proximal airway and distal trachea. No combination of circuit and sampling site produced a flat alveolar phase until the circle circuit was modified with diversion valves to reduce gas mixing. The mean PaCO₂-PeCO₂ gradients using the coaxial/proximal sampling, coaxial/distal sampling, and modified circle/proximal sampling circuits were 12.4, 9.2, and 8.8 mm Hg, respectively. The mean PeCO₂ in each of these combinations was significantly different from the corresponding mean PaCO₂ (p<0.05). Using the modified circle circuit with distal sampling, mean PeCO₂ was not significantly different from mean PaCO₂: the mean PaCO₂-PcCO₂ gradient was 2.2 ± 0.2 mm Hg (SEM), range, 0 to 6 mm Hg, with 95% confidence limits ⩽ 8 mm Hg. When a coaxial breathing circuit is used in small subjects, PaCO₂ may be significantly underestimated regardless of sampling site, although the circle breathing circuit with distal tracheal sampling yields accurate results. Supported in part by BRS Grant SO RR05507-20 from the Biomedical Research Support Grant Program, Division of Research Resources, National Institutes of Health, and by the American Heart Association, Lancaster, PA Chapter. The authors thank Robert Hirsch, PhD, for his statistical advice, and Greg Harris and Perkin-Elmer, Inc for loaning the mass spectrometer.     

Limited functional grouping of neurons in the motor cortex hand area during individuated finger movements: A cluster analysis

Primary motor cortex (M1) hand area neurons show patterns of discharge across a set of individuated finger and wrist movements so diverse as to preclude classifying the neurons into functional groups on the basis of simple inspection. We therefore applied methods of cluster analysis to search M1 neuronal populations for groups of neurons with similar patterns of discharge across the set of movements. Populations from each of three monkeys showed a large group of neurons the discharge of which increased for many or all of the movements and a second small group the discharge of which decreased for many or all movements. Two to three other small groups of neurons that discharged more specifically for one or two movements also were found in each monkey, but these groups were less consistent than the groups with broad movement fields. The limited functional grouping of M1 hand area neurons suggests that M1 neurons act as a network of highly diverse elements in controlling individuated finger movements.     

Hemodynamic effects of halothane in the newborn piglet

In order to better understand the mechanism of hypotension and bradycardia in newborn infants under halothane anesthesia, we studied the changes in the four determinants of cardiac output in newborn piglets given 0.5 and 1% end tidal halothane. Cardiac index (CI) was measured by thermodilution. Preload was estimated from the left ventricular diastolic dimension determined by echocardiography and from the left ventricular end-diastolic pressure. Total peripheral resistance index was calculated to assess afterload. Contractility was estimated from left ventricular peak dP/dT, and from left ventricular shortening fraction and mean rate of circumferential fiber shortening determined by echocardiography. All indices of contractility decreased to approximately 50% of baseline values during administration of 1% halothane, whereas heart rate (HR) was reduced to 74% of baseline. Preload and afterload did not change significantly. Mean arterial pressure (MAP) and CI decreased to 67% and 74% of control values, respectively. Smaller, proportional reductions in all variables occurred when 0.5% halothane was administered. Control values of MAP were the only measurements significantly related to piglet age. When five additional animals underwent atrial pacing at the control HR during 1% halothane anesthesia, MAP and CI decreased to 66 and 71% of control values, respectively. dP/dT/DP40, a dP/dT point measurement independent of preload and afterload changes, decreased to 49% of control during pacing. Therefore, the major effect of halothane in newborn piglets is its potent negative inotropic action, not peripheral vasodilation or bradycardia.     

Geographic variation in physicians' fees. Payments to physicians under Medicare and Medicaid.

To study geographic differences in physician fees recognized by the Medicare and Medicaid programs, we analyzed physician reimbursement rates at the national, regional, state, and county levels. The results indicate that nationally, Medicaid specialist fees are 77% of Medicare specialist fees. Meidcare specialist fees in metropolitan areas are 23% higher than those in nonmetropolitan areas, but there are no differences under Medicaid. State Medicare specialist fees varied from 73% to 132% of the national Medicare average, while Medicaid specialist fees ranged from 49% to 179% of the national Medicaid average. State Medicaid fees for specialists ranged from 39% to 100% of Medicare specialist fees. These results indicate that under national health insurance, fees set at national or statewide levels could have notable effects on physician remuneration in some localities.