Daniel J. McCarty

Simple method for measurement of lower extremity muscle strength

A simple, rapid, reproducible method for quantification of lower extremity muscle strength was standardized. The time needed to stand 10 times from a standard chair was recorded in 139 healthy subjects, aged 20 to 85 years (77 men, 62 women). Reproducibility was 6.8 percent (+/- 3.4 percent). Neither height nor weight was related to time in either sex. Weight was related to time (p less than 0.05) after adjusting for age, but this effect was slight compared with the effect of age alone. A highly significant (p less than 0.0001) relationship between time and age was found in both sexes. Younger men performed better than younger women, although this difference was lost in the older age groups. The results of this simple test correlated well with published data on the strength of knee flexor and extensor muscles in groups of men and women of various ages. This method was used to evaluate serially six consecutive patients with classic polymyositis or dermatomyositis. Improvement after treatment with prednisone used alone or in combination with azathioprine or methotrexate was found in all cases.

The reflex sympathetic dystrophy syndrome: II. Roentgenographic and scintigraphic evidence of bilaterality and of periarticular accentuation☆

Patchy osteoporosis is the primary roentgenologic manifestation of the reflex sympathetic dystrophy syndrome (RSDS). As recent clinical and histologic data suggested articular changes in RSDS, fine-detail roentgenograms were obtained in eight consecutive patients. Juxta-articular and soft-tissue swelling, osteoporosis and erosions of the subchondral bone were found. 99mTcO4 and 99mTc-EHDP scintigraphy showed localization of nuclide predominantly in the juxta-articular tissues. Serial roentgenographic, scintigraphic and quantitative bone densitometric measurements showed changes that reflected the clinical course of the disease.

Geographic variation of inflammatory bowel disease within the United States

One approach to learn about possible environmental risks in inflammatory bowel disease relates to studying its geographic pattern of occurrence. The geographic variation of inflammatory bowel disease within the United States was analyzed using the accumulated 17.5 million hospital discharges of all U.S. Medicare beneficiaries during two consecutive years. To validate the geographic pattern shown by the Medicare data, hospitalization was compared with mortality from inflammatory bowel disease among different states. Mortality and hospitalization statistics both suggested that the occurrence of inflammatory bowel disease was determined by environmental factors that had a marked geographic variation within the United States. Both Crohns disease and ulcerative colitis appeared to be more frequent in northern parts of the United States than in southern and in urban more than rural parts. These trends were observed for men and women and for blacks and whites alike. Similar geographic patterns of Crohns disease and ulcerative colitis suggested the influence of one or more identical risk factors for both diseases.

The reflex sympathetic dystrophy syndrome: I. Clinical and histologic studies: Evidence for bilaterality, response to corticosteroids and articular involvement

Eleven consecutive patients fulfulling criteria for the reflex sympathetic dystrophy syndrome (RSDS) were studied by quantitative clinical methods, providing measurements of swelling (ring size), tenderness (dolorimeter) and functional capacity (grip strength). The predominantly affected extremity was clearly identified by these technics and its serial progress determined in six patients. Corticosteroid therapy predictably resulted in improvement of all treated patients. Greater tenderness was found in the joints than in the interjoint areas, indicating a possible accentuation of the disease process in juxta-articular tissues. Synovial biopsy specimens in four patients were abnormal, and the histology was presented in detail for the first time. All patients showed bilateral involvement during the study, providing evidence for a central neural mechanism in the RSDS.

The reflex sympathetic dystrophy syndrome. A comprehensive analysis using fine-detail radiography, photon absorptiometry, and bone and joint scintigraphy.

Nine patients with reflex sympathetic dystrophy were examined. Clinical manifestations suggesting arthropathy were supported by radiographic demonstration of juxta-articular and subchondral bone erosions and by radionuclide demonstration of increased activity localized in the joint regions. Aggressive demineralization was demonstrated by fine-detail radiography and consisted of endosteal and intracortical excavation and subperiosteal and trabecular bone resorption. A one-third reduction in bone mineral was confirmed by quantitative analyses. Newer modalities of study have aided in the documentation of arthropathy in reflex sympathetic dystrophy and have helped in defining the patterns of aggressive bone resorption.

Release of platelet constituents by monosodium urate crystals.

The release of human platelet constituents by the etiologic agent of gout, the monosodium urate crystal, is described here. In suspensions of washed platelets, response to urate crystals proceeded in two phases: A secretory phase involved the rapid active release of serotonin, ATP, and ADP with little loss of lactic dehydrogenase or beta-glucuronidase. A lytic phase involved the slower loss of all platelet constituents. Both phases were inhibited by iodoacetate plus dinitrophenol, suggesting an energy requirement. In ultrastructural studies, lysis of washed platelets which appeared to contain crystals was seen. Urate crystals were also shown to induce serotonin release and platelet lysis in citrated platelet-rich plasma. Since urate crystals are deposited at a variety of sites, urate crystal-platelet interaction in vivo is a possibility. Such interactions, leading to release of platelet constituents, might contribute to gouty inflammation or to enhanced atherogenesis.

Mitogenesis induced by calcium-containing crystals: Role of intracellular dissolution

Hydroxyapatite, like other calcium-containing crystals previously studied by us, is mitogenic for cultured human fibroblasts. This mitogenic effect is not a result of increased ambient calcium concentration due to extracellular crystal dissolution. Synthetic crystals labelled uniformly with calcium 45 (45Ca) undergo endocytosis when incubated with cells and are solubilized. Such solubilization is inhibited by chloroquine or ammonium chloride in concentrations that significantly block the mitogenic effect of crystals but not that of serum. The data suggest that mitogenesis and intracellular crystal dissolution are related phenomena.

Running Elevates Plasma β-Endorphin Immunoreactivity and ACTH in Untrained Human Subjects

Abstract Twenty minutes of submaximal treadmill running was associated with an elevation in plasma levels of β-endorphin immunoreactivity (P < 0.02). This increase was greater in men (14.9 ± 3.4 fmole/ml) than women (2.6 ± 1.2 fmole/ml) (P < 0.05). Plasma levels of ACTH and growth hormone also increased after running. ACTH increased more in men (7.8 ± 1.1 fmole/ml) than in women (1.1 ± 0.44 fmole/ml) (P < 0.02). There was a similar growth hormone response in both sexes. No correlation can at this time be made with levels in the central nervous system. Changes in plasma levels of β-endorphin immunoreactivity may be responsible for some of the euphoria and analgesia anecdotally associated with running.

Cultured human monocytes and fibroblasts solubilize calcium phosphate crystals

SummaryTwo rheumatic syndromes associated with deposition of calcium phosphate crystals in soft tissues of the shoulder have prompted us to study the cellular mechanisms of calcium phosphate crystal solubilization. Synthetic45Ca labeled calcium phosphate crystal aggregates were solubilized by cultured human fibroblasts or monocytes. Such solubilization required crystal cell contact and was inhibited by chloroquine and ammonium. We hypothesize that the mechanism of crystal solubilization involves phagocytosis followed by dissolution in the acidic environment of secondary lysosomes. Study of the mechanism of calcium phosphate solubilization may be important in understanding resorption of extra-osseus as well as osseus calcification. Intracellular release of calcium from calcium phosphate crystals may also explain our previous observation that hydroxyapatite and other calcium-containing crystals are mitogenic stimuli for fibroblasts and synovial cells.

Why Are Today's Medical Students Choosing High-Technology Specialties over Internal Medicine?

The annual meeting of the Association of Professors of Medicine, an organization of the chairpersons of the departments of medicine of our nations 125 medical schools, was held last May. Much of t...