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Biomedical subjects

D J McCarty

Publications and source records attributed to D J McCarty.

At least 37 records · Page 2Linked to original sources

Nucleotide pyrophosphohydrolase in human synovial fluid.

OBJECTIVE: To identify the molecular forms of ectonucleotide pyrophosphohydrolase (NTPPHase) in human synovial fluid (SF). METHODS: We examined synovial fluids from 32 patients with various joint diseases [10 calcium pyrophosphate dihydrate (CPPD) deposition disease; 7 osteoarthritis (OA); 6 rheumatoid arthritis (RA); 3 after total knee arthroplasty (TKA); 6 olecranon bursa] and 3 normal joint fluids. Joint fluids were analyzed after sequential centrifugation for NTPPHase activity and by Western blot using polyclonal antibodies against 127 kDa porcine articular cartilage vesicle-associated NTPPHase and against PC-1 and 58 kDa, 2 other ecto-NTPPHases. Lysate from human synoviocytes, porcine chondrocytes, and their conditioned media were examined using antibodies to these ecto-NTPPHases. Radiographs of joints from which fluid was obtained were graded for degenerative changes 0-4 using a standard method. RESULTS: NTPPHase activity was found in all pathological and normal SF tested and correlated with the degree of radiographic degeneration (r = 0.55, p < 0.05). NTPPHase specific activity in ultracentrifugation pellets was highest in CPPD deposition disease fluids (p < 0.05). 127 kDa enzyme was found in both sedimentable and soluble fractions from CPPD, OA, TKA, and normal fluids, and was extensively degraded in all inflammatory fluids. Intact 115 kDa PC-1 was found only in the 2 CPPD fluids with the highest NTPPHase activity. 58 kDa enzyme was found in most fluids, predominantly in the soluble fraction. 127 kDa protein was identified in human synoviocyte conditioned media but not in cell lysate, while PC-1 and 58 kDa proteins were found in the cell lysate but not in the conditioned media. CONCLUSION: There was no disease specific association with any one ecto-NTPPHase. Total enzyme activity correlated with the degree of degenerative change. The specific activity of pelletable 127 kDa enzyme was higher in fluids containing CPPD crystals. All 3 ecto-NTPPHases or their presumed degradation products were detectable in some pathologic and normal fluids. A 200 kDa reactive band often accompanied reactivity to the 127 kDa enzyme. PC-1 and 127 kDa proteins were extensively degraded in inflammatory SF, while 58 kDa protein was not. The relative contribution of each of these enzymes to inorganic pyrophosphate production by human joint tissues remains unclear.

Animals↗

The rising global burden of diabetes and its complications: estimates and projections to the year 2010.

Prevention and control programmes are needed to stem the rising epidemic of diabetes and its complications. However, these will not occur unless governments and public health planners are aware of the potential problem. Using published prevalence rates for NIDDM in different populations, and the current and projected age distributions, worldwide prevalence of NIDDM was estimated for 1995 and 1997, and well as projections for 2000 and 2010. Prevalence rates used for projections were chosen to reflect changes in lifestyle with economic development. The global prevalence of IDDM was estimated using published incidence rates and population figures, incorporating the likely survival time from development of IDDM. Data on diabetes complications are also summarised but no attempt has been made to extrapolate to a global estimated. In 1997, an estimated 124 million people worldwide have diabetes, 97% of these having NIDDM. By the year 2010 the total number of people with diabetes is projected to reach 221 million. The regions with the greatest potential increases are Asia and Africa, where diabetes rates could rise to 2 or 3 times those experienced today. With improvements in the treatment of IDDM, the prevalence of this form of diabetes is likely to increase as more people survive for longer after diagnosis. Increases in complications will undoubtedly follow increasing prevalence of diabetes, but population-based studies using standardised methods of diagnosis are required before reliable estimates of the extent of the problem can be made. It is hoped that the information provided in this report, and others like it, will act as an incentive to initiate or improve local diabetes monitoring and prevention strategies.

Diabetes Complications↗

Specificity of a porcine 127-kd nucleotide pyrophosphohydrolase for articular tissues.

OBJECTIVE: To determine the tissue specificity of a porcine 127-kd nucleotide pyrophosphohydrolase (NTPPHase) found in vesicles derived from hyaline articular cartilage (ACV). METHODS: Homogenates of porcine brain, lung, liver, kidney, urinary bladder, pancreas, spleen, skin, vena cava, marrow, bone (cells), tendon (Achilles), ligament (anterior cruciate), elastic cartilage, meniscus, and hyaline cartilage were analyzed for NTTPHase activity (thymidine monophosphate paranitrophenyl ester substrate) and by Western blot using polyclonal antibodies against 127-kd NTPPHase and against recombinant PC-1, another ecto-NTPPHase. RESULTS: All tissues contained NTPPHase activity; the highest specific activity was found in hyaline articular cartilage, the lowest in brain. ACV-associated 127-kd NTTPHase was expressed in cartilage, ligament, and tendon. PC-1 was also expressed in those tissues and in skin, kidney, bone cells, and (probably) in liver and muscle. CONCLUSION: The 127-kd NTPPHase appears to be highly specific for articular tissues.

Animals↗

Identification of a nucleotide pyrophosphohydrolase from articular tissues in human serum.

OBJECTIVE: To characterize the nucleotide pyrophosphohydrolase (NTPPHase) in human serum. METHODS: NTPPHase activity and kinetic analysis were performed using thymidine monophosphate paranitrophenyl ester (TMPNP) or 32Pgamma-labeled ATP as substrate. Sera were chromatographed (dye column), and peak fractions were analyzed kinetically and by immunoblot using antibodies to 127-kd articular cartilage vesicle (ACV) NTPPHase as well as to PC-1 and to 58 kd, two plasma membrane ecto-NTPPHases. Enzyme activity was measured before and after sample ultracentrifugation. RESULTS: NTPPHase activity was found in all sera tested (2 normal subjects, 9 arthritis patients). Specific activity was increased 9-32-fold after chromatography; 60-80% of total activity was recovered in a single peak containing an approximately 100-kd soluble peptide related to the 127-kd ACV enzyme. The apparent Km of this peptide (TMPNP) was virtually identical to that of the porcine ACV 127-kd enzyme. No immunoreactivity against PC-1 or 58-kd NTPPHase was found. CONCLUSION: Human serum NTPPHase is derived from 127-kd ACV-related enzyme.

Adenosine Triphosphate↗

Inorganic pyrophosphate generation from adenosine triphosphate by cell-free human synovial fluid.

OBJECTIVE: To quantify inorganic pyrophosphate (PPi) production from extracellular adenosine triphosphate (ATP) by human synovial fluids (SF). METHODS: Serial measurements of ATP hydrolysis rate (t1/2) were performed by the luciferase method from a starting concentration of 500 nM in 21 pathologic and one normal cell-free SF samples incubated under physiologic conditions. ATP was then pumped into a sample of each fluid, using the rate constant derived from the t1/2 of that fluid, to provide steady state levels simulating those reported in SF. Trace [32P] gamma ATP was added at the start of the infusion; conversion to [32P] Pi and to [32P] PPi was determined by precipitation of Pi as reduced phosphomolybdate before and after treatment with yeast inorganic pyrophosphatase. Finally, the pumping experiment was repeated and PPi production was calculated from direct measurement of PPi at time zero and at 60 min. PPi hydrolysis was measured in each fluid by [32P] Pi precipitation from [32P] PPi tracer added at time zero. RESULTS: ATP was hydrolyzed by all SF. The mean t1/2 (seconds) in 8 osteoarthritis (OA) samples was 72 s, in 5 calcium pyrophosphate dihydrate (CPPD) 30 s (p < 0.02), in 3 rheumatoid arthritis (RA) 1160 s, in normal 86 s, in 3 olecranon bursal (OB) 54 s, and in 2 total knee replacement fluid samples 17 and 121 s. The major product of ATP hydrolysis was PPi in all but 2 fluids (1 RA, 1 OB), even at lower than steady state levels. At simulated in vivo steady state ATP levels, mean conversion of APT to PPi was stoichiometric in OA and CPPD fluids. PPi hydrolysis was < 4% in all noninflammatory fluids. CONCLUSION: PPi is the major product of extracellular ATP catabolism in most SF. Hydrolysis rates were significantly faster in SF containing CPPD crystals. Mean PPi production by these fluids at simulated in vivo steady state levels was 6-fold that of OA SF (p < 0.01). Hydrolysis of extracellular ATP by ectonucleotide pyrophosphohydrolases can account for all PPi produced by joint issues previously estimated from [32P] PPi pool and turnover studies in human knee joints.

Adenosine Triphosphate↗

Generation of inorganic pyrophosphate from extracellular adenosine triphosphate by human serum and plasma.

OBJECTIVE: To quantify inorganic pyrophosphate (PPi) production from extracellular adenosine triphosphate (ATP) by human serum or plasma. METHODS: Serial measurements of ATP hydrolysis (t1/2) were performed by the luciferase method from a starting concentration of 1 microM in serum or platelet-poor plasma incubated under physiologic conditions. ATP was then pumped into another sample of each specimen using the rate constant derived from the ATP t1/2 of that specimen. Trace (32P) gamma ATP was added at the start of the infusion; conversion to (32P) inorganic orthophosphate (Pi) and to (32P) PPi was determined by precipitation of Pi as reduced phosphomolybdate before and after treatment with yeast pyrophosphatase. RESULTS: ATP was hydrolyzed by all serum and plasma specimens; the rate of hydrolysis in serum and plasma from the same blood sample was nearly identical. PPi was the major product, averaging 71%. CONCLUSION: PPi is the major product of ATP catabolism in serum and platelet-poor plasma.

Adenosine Triphosphate↗

Adenosine triphosphate levels in human plasma.

OBJECTIVE: To quantify extracellular adenosine triphosphate (ATP) levels in human platelet-poor plasma as a potential source of synovial fluid ATP, and to determine variables affecting these levels. METHODS: ATP was measured by the specific luciferase method; platelet beta thromboglobulin was determined by radioimmunoassay. The effects of fasting, feeding, venipuncture, and muscular exercise were determined by serial venipuncture in healthy subjects. Diurnal variation was determined by serial sampling through indwelling venous catheters in 3 healthy subjects and 3 women with knee osteoarthritis. RESULTS: Unlike beta thromboglobulin levels, which did not change, an invariable marked (mean 58%) fall in plasma ATP was noted 15 min after the first venipuncture, whether the subject had eaten or not. Indomethacin treatment had no effect on this phenomenon. Exercise of forearm muscles had no effect on plasma ATP. The drop in plasma ATP occurred between 3 and 15 min, with recovery at about 90 min. A diurnal variation in plasma ATP was found with trough levels at noon and at night during sleep. CONCLUSION: The predictable sharp fall in plasma ATP levels induced by venipuncture and the clear diurnal variation suggest that plasma contains ATP independent of platelet dense body release and endothelial cell needle trauma. Synovial plasma flow at peak (600 nM) levels is insufficient to provide more than one-third of the extracellular ATP needed to generate inorganic pyrophosphate in articular tissues.

Adenosine Triphosphate↗

Incidence of systemic lupus erythematosus. Race and gender differences.

OBJECTIVE: To examine racial differences in the incidence of systemic lupus erythematosus (SLE). METHODS: A population-based registry of SLE patients in Allegheny County, Pennsylvania, was used to identify incident cases of SLE diagnosed between January 1, 1985 and December 31, 1990, from 3 sources, by medical record review (University of Pittsburgh Lupus Databank, rheumatologists, and hospitals). Capture-recapture methods using log-linear models were used to estimate the level of case-finding and to calculate 95% confidence intervals (CI). Incidence rates were calculated per 100,000 population. RESULTS: A total of 191 definite and 78 probable incident cases of SLE were identified, and the overall annual incidence rates were 2.4 (95% CI 2.1-2.8) and 1.0 (95% CI 0.8-1.3), respectively. The crude incidence rates of definite SLE were 0.4 for white males, 3.5 for white females, 0.7 for African-American males, and 9.2 for African-American females. The annual incidence rates of definite SLE remained fairly constant over the study interval. African-American females with definite SLE had a younger mean age at diagnosis compared with white females (P < 0.05). Since the overall ascertainment rate was high (85%; 95% CI 78-92%), the ascertainment-corrected incidence rate for definite SLE, 2.8 (95% CI 2.6-3.2), was similar to the crude rate. CONCLUSION: Our rates clearly confirm previous reports of an excess incidence of SLE among females compared with males and among African-Americans compared with whites. We have used capture-recapture methods to improve the accuracy of SLE incidence rates, and we advocate their use to facilitate comparisons across studies.

Adolescent↗

The 1984 Tasmanian insulin treated diabetes mellitus prevalence cohort: an eight and a half year mortality follow-up investigation.

Total mortality and underlying cause of death were examined in a population-based prevalence cohort (n = 1232) of Tasmanians with insulin-treated diabetes mellitus. Eight and a half years after the establishment of the registry, the cause of death based on death certificate information was determined for the overall cohort and for three classification groups of insulin-treated diabetes: Group A--childhood-onset IDDM cases; Group B--adult-onset IDDM cases; and Group C--adult-onset insulin-treated NIDDM cases. A total of 378 deaths occurred, providing an overall SMR of 2.2 (95% CI 2.0-2.4) compared to the Tasmanian population. Diabetic females experienced a higher SMR (2.6, 95% CI 2.3-3.0) than diabetic males (1.9, 95% CI 1.6-2.2). The all-cause SMRs for the diabetic classification groups were 4.6 (95% CI 3.4-6.1) in Group A, 1.8 (95% CI 1.5-2.1) in Group B, and 2.2 (95% CI 1.9-2.6) in Group C. After adjusting for age, gender and duration of diabetes, the mortality in Group C was significantly higher compared to Group B (odds ratio 1.6, 95% CI 1.2-2.3). This study indicates that people with childhood-onset IDDM experience 4.6 times the death rate compared to the Tasmanian population and that the excess mortality is most pronounced in females.

Adolescent↗

A unique ectonucleotide pyrophosphohydrolase associated with porcine chondrocyte-derived vesicles.

Previous studies have shown increased nucleotide pyrophosphohydrolase (EC 3.6.1.8) (NTPPHase) activity in detergent extracts of degenerated human cartilage containing calcium pyrophosphate dihydrate (CPPD) crystals relative to those from osteoarthritis or normal cartilage. NTPPHase was later shown to be an ectoenzyme and its activity was increased in synovial fluid from patients with CPPD crystal deposits relative to fluids from other types of arthritis. We have purified a soluble 61-kD NTPPHase from conditioned media of organ-cultured porcine articular cartilage to electrophoretic homogeneity. Its NH2-terminal sequence through 26 cycles showed < 30% homology to any previously reported protein sequence. An antibody raised to a synthetic peptide corresponding to this sequence reacted with denatured but not native enzyme. This antibody reacted against a sedimentable vesicle-associated 127-kD protein in conditioned media from cultured articular cartilage or from chondrocytes in primary monolayer culture and against a series of soluble proteins in conditioned media supernatant, including a 61-kD protein representing our original isolate. No reactivity was found in 1% SDS extracts of washed cultured chondrocytes, although these contained greater NTPPHase activity than the conditioned media. Antibody to PC-1, another ectoNTPPHase, reacted with 1% SDS extracts of whole chondrocytes but not against those chromatographic fractions containing the major portion of NTPPHase activity. Release of the vesicle-associated 127-kD enzyme into conditioned medium was stimulated three- to sevenfold by TGF beta 1. The antibody also reacted with a series of soluble proteins and with 127-kD sedimentable protein in human synovial fluid. Kinetic studies supported the existence of a unique vesicle-associated NTPPHase; apparent Km (mM) of chondrocyte membrane NTPPHase was 1.5 and 3.0 at pH 7.3 and 9.88, respectively; apparent Km (mM) of vesicle associated NTPPHase was 0.83 and 1.28 at pH 7.3 and 9.88. The data suggest the existence of a unique ecto-NTPPHase associated with vesicles derived from normal articular cartilage.

Amino Acid Sequence↗

Treatment of rheumatoid joint inflammation with intrasynovial triamcinolone hexacetonide.

OBJECTIVE: To determine the effectiveness of intrasynovial triamcinolone hexacetonide coupled with joint rest (3 weeks upper extremity; 6 weeks lower extremity) in the treatment of joint and tendon sheath inflammation in patients with seropositive rheumatoid arthritis (RA). METHODS: The medical records of 169 patients with seropositive RA treated by a single rheumatologist for at least one year between 1974 and 1992 were abstracted. RESULTS: Nine hundred fifty-six injections were given to 140 patients; approximately 75% of injected synovial structures remained in remission during a mean followup 7 years; 218 injections were given into previously treated structures. The injection rate was about 2 per patient in the first year, half of which were given at the time of the first visit. The rate then approximated 0.6 injections per patient-year for the next 15 years. Joints in the right upper extremity were injected significantly (p = 0.01) more frequently than those on the left. CONCLUSION: Intrasynovial triamcinolone hexacetonide followed by rest is a very useful adjunctive modality in the treatment of seropositive rheumatoid arthritis.

Anti-Inflammatory Agents↗