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Biomedical subjects

C Patton

Publications and source records attributed to C Patton.

At least 19 recordsLinked to original sources

Calcium supplementation prevents seasonal bone loss and changes in biochemical markers of bone turnover in elderly New England women: a randomized placebo-controlled trial.

Elderly women are at increased risk for bone loss and fractures. In previous cross-sectional and longitudinal studies of women residing in northern latitudes, bone loss was most pronounced during winter months and in those consuming less than 1 g calcium per day. In this study we sought to test the hypothesis that calcium supplementation by either calcium carbonate or dietary means would prevent seasonal bone loss and preserve bone mass. Sixty older postmenopausal women without osteoporosis were randomized to one of three treatment arms: Dietary milk supplementation (D-4 glasses of milk/day), Calcium carbonate (CaCO3-1000 mg/day in two divided doses), or placebo (P). After 2 yr, placebo-treated women consumed a mean of 683 mg/day of calcium and lost 3.0% of their greater trochanteric (GT) bone mineral density (BMD) (P < 0.03 vs. baseline); Dietary supplemented women averaged a calcium intake of 1028 mg/day and sustained minimal loss from the GT (-1.5%; P = 0.30), whereas CaCO3-treated women (total Ca intake, 1633 mg/day) suffered no bone loss from the GT and showed a significant increase in spinal and femoral neck BMD (P < 0.05). Femoral bone loss occurred exclusively during the two winters of the study (i.e. total loss, -3.2%; P < 0.02 in placebo-treated women) with virtually no change in GT BMD during summer. Serum 25-OH vitamin D declined by more than 20% (P < 0.001) in all groups during the winter months but returned to baseline in summer; PTH levels rose approximately 20% (P < 0.001) during winter but did not return to baseline during the summers. Urine N-telopeptide and osteocalcin levels increased significantly but only in the P-treated women and only during winter. Serum insulin growth factor binding protein 4, an inhibitory insulin growth factor binding protein, rose 15% (P < 0.03) from summer to winter, but this increase was significant only in those women consuming <1000 mg/day of calcium. By multivariate analysis, total calcium intake was the strongest predictor of bone loss from the hip. Urinary N-telopeptide also closely correlated with GT BMD but only during winter (P = 0.003). We conclude that calcium supplementation prevents bone loss in elderly women by suppressing bone turnover during the winter when serum 25-OH vitamin D declines and serum PTH increases. The precise amount of calcium necessary to preserve BMD in elderly women requires further studies, although in this study, at least 1000 mg/day of supplemental calcium was adequate prophylaxis against femoral bone loss.

Aged

A mixed foodborne outbreak with Salmonella heidelberg and Campylobacter jejuni in a nursing home.

OBJECTIVE: To investigate a mixed Salmonella heidelberg and Campylobacter jejuni foodborne outbreak in a nursing home. DESIGN: Retrospective cohort study with a nested case-control design. Cases were defined by positive stool-culture results. Controls needed to be both asymptomatic and culture-negative. SETTING AND PATIENTS: Residents of a 580-bed nursing home in Brooklyn, New York. RESULTS: Of the 580 residents, 119 (21%) developed illness. Of the 93 symptomatic patients who submitted specimens, cultures were positive for S heidelberg in 24 (26%), C jejuni in 14 (15%), and both microorganisms in 25 (27%). Only the pureed diet was associated highly with infection by either Salmonella (odds ratio [OR], 17.6; 95% confidence interval [CI95], 4.8-68.7; P < .001), Campylobacter (OR, 13.3; CI95, 3.2-59.2; P < .001), or both organisms (OR, 8.9; CI95, 2.7-30.3; P < .001). Among the 42 pureed foods served during the 5 days before the outbreak, five meat or poultry items were associated most strongly with culture positivity. Of these five meat items, only a chopped-liver salad was implicated by the two employees reporting illness. A reported food-handling error occurred when ground, cooked chicken livers were placed in a bowl containing raw chicken-liver juices. INTERVENTION: Recommendations for proper cleaning and sanitizing of kitchen equipment to prevent cross-contamination between raw and cooked foods. CONCLUSIONS: Mixed foodborne outbreaks occur rarely. During this outbreak, contamination of a single food item with multiple bacterial pathogens was the likely source of transmission. Improper food-handling techniques that promote growth of one microorganism also allow growth of other pathogens that may be present. Because different sources and routes of transmission may be implicated for different pathogens, specific preventive measures may vary depending on the organisms involved.

Campylobacter Infections

Protein synthesis increases after fertilization of sea urchin eggs in the absence of an increase in intracellular pH.

We have reevaluated the presumed requirement for an elevated intracellular pH (pHi) in the acceleration of protein synthesis which follows fertilization of eggs of the sea urchin Lytechinus pictus. Zygotes were transferred to sea water at a low pH (6.8) containing a permeant weak acid at times ranging from 5 min to as early as 30 sec postinsemination, to reverse or prevent the rise in pHi that normally ensues upon fertilization. Using the fluorescent pH probe 2',7'-bis(carboxyethyl)-5(6)-carboxyfluorescein (BCECF), we show that transfer of zygotes at 1 min or earlier after fertilization essentially blocks the rise in pHi. Under these conditions, both the incorporation of radiolabeled leucine into protein and the assembly of ribosomes into polysomes increase substantially (> 50% of control values). We also assessed leucine incorporation during incubation of eggs and zygotes in sodium-free sea water or sea water containing amiloride, two additional treatments that block the pHi rise. In the presence of amiloride, leucine incorporation increased upon fertilization, whereas little or no increase was observed in sodium-free sea water. We provide evidence that the low rates of leucine incorporation in sodium-free sea water result from the tendency for this experimental condition to lower the pHi to values significantly lower than the pHi in unfertilized eggs. These findings call into doubt the belief that the pHi rise at fertilization is a necessary prerequisite for the acceleration of bulk protein synthesis. These observations support the view that pHi is only one of several signals involved in the turn on of protein synthesis at the time of fertilization of sea urchin eggs.

Amiloride

Repair of multiple mycotic aortic aneurysms in a newborn.

Thoracoabdominal aortic and common and internal iliac artery mycotic aneurysms resulted from an umbilical arterial catheter in a 3 1/2-week-old boy. He underwent staged repair including an 8-mm Gore-tax tube graft, primary repair of the common iliac artery aneurysm, and resection of the internal iliac aneurysm. His operative and postoperative course was uneventful. He was asymptomatic at 17 months' follow-up, with equal blood pressure in the upper and lower extremities. Magnetic resonance imaging showed no stenoses or recurrent aneurysms at the anastomotic sites of the Gore-tex tube graft. Blood supply to his left leg came from collaterals, principally a large crossing vessel from the right iliac artery. This case represents the first successful aortic replacement in a 5 week old with extensive involvement of the thoracoabdominal aorta and its branch vessels.

Aneurysm, Infected

Late results (30 to 35 years) after operative closure of isolated ventricular septal defect from 1954 to 1960.

This study was designed to determine the clinical status, cause of death, and effects of pulmonary vascular disease and conduction abnormalities 30 to 35 years after surgery in 296 consecutive surviving patients of closure of ventricular septal defect. Of the 296 patients, current status was determined by contact with patient and physician in 290 cases, with 6 (2%) lost to follow-up (7,912 patient years are included). Cardiac catheterization after surgery in 168 patients showed complete closure of the defect in 80%. Death occurred in 59 patients (20%), with higher mortality rates in those operated on after the age of 5 years, those with pulmonary vascular resistance greater than 7 units (51%), and those with complete heart block (78%). Of 37 patients with transient heart block after surgery, 8 (22%) have died (3 pulmonary vascular disease, 2 sudden death, 2 unknown causes and 1 complete heart block). Twenty other patients had a dysarrhythmia after surgery, and none of these died. Nine episodes of endocarditis occurred (11.4/10,000 patient years). Nine of 296 (3%) offspring had cardiac malformation. Most patients are in New York Heart Association class I, 57% attended college and 15% received an advanced degree. The data show good results for this group of patients operated on during an early era (1954 to 1960) of open cardiac surgery. They support the current trend toward operation in patients with ventricular septal defects at an early age and with low pulmonary vascular resistance.

Adult

Analytic and preparative separation of apolipoproteins A-I, A-II, and A-IV by reverse phase high pressure liquid chromatography.

We have developed a rapid reverse phase high pressure liquid chromatographic technique capable of separating apolipoproteins A-I, A-II, and A-IV and their constituent isoforms. The separations were performed on a 30 cm x 3.9 mm C18 reverse-phase silica-based column (Waters Associates) using a 47-55% gradient of acetonitrile in 0.1% trifluoroacetic acid. Injection of a mixture of equal weights of apolipoproteins A-I, A-II, and A-IV yielded a single peak for apoA-IV, two peaks of apoA-I isoforms, and three peaks of apoA-II isoforms, with negligible overlap of each peak. When applied to the isolation of apoA-IV from a crude protein mixture obtained by incubation of phospholipid-triglyceride emulsion particles with lipoprotein-depleted plasma, the technique yielded a single peak of highly pure apoA-IV cleanly separated from isoforms of apoA-I and higher molecular weight proteins. A positive linear correlation was observed between apoprotein hydrophobicity and column retention time, thus indicating that the system provided a true reverse phase separation. We conclude that reverse phase high pressure liquid chromatography can separate human apolipoprotein A-IV from isoforms of apoA-I and apoA-II on the basis of differences in mean molecular hydrophobicity. The technique has direct application to the isolation of human apolipoprotein A-IV.

Apolipoprotein A-I

The first open-heart repairs of ventricular septal defect, atrioventricular communis, and tetralogy of Fallot using extracorporeal circulation by cross-circulation: a 30-year follow-up.

From March 26, 1954, to July 19, 1955, 45 patients with major cardiac malformations not previously correctable underwent open repair utilizing cross-circulation between patient and donor without donor deaths. All operations were carried out at normothermia with lowered flow rates based on azygos flow studies. Twenty-seven patients, more than half of them infants, had ventricular septal defects closed. There were 8 hospital deaths, and there have been only 2 late deaths in 30 years. Fourteen (87.5%) of 16 who underwent recatheterization have closed defects. The 17 30-year-survivors are all in New York Heart Association Functional Class I. Five patients 4 months to 10 years old were operated on for atrioventricular canal (complete form). All had intractable failure, and 4 had pulmonary hypertension. Two of the 3 hospital deaths were due to heart block. The long-term survivor, a 15-month-old infant at the time of operation (severe pulmonary hypertension, 90/50 mm Hg), underwent repair 31 years ago and is now married with 3 children. Recatheterization disclosed normal pulmonary pressure (20/4 mm Hg), no shunts, and mild mitral regurgitation. Ten cyanotic tetrads 13 months to 14 years old were operated on with 5 hospital deaths. Of the 3 late deaths, 1 was accidental at 17 years, 1 occurred suddenly at home 13 years after operation in infancy for atresia, and the third occurred at reoperation 10 years later. The 2 remaining patients (1 the first patient operated on) are in excellent health. The surgical methods used and the physiological advantages of cross-circulation (temporary placenta) that made these results possible at a time when surgical knowledge was primitive are described.

Cardiac Catheterization

Predictive value of lung biopsy in ventricular septal defect: long-term follow-up.

Although the Heath-Edwards classification has been used for more than 25 years to evaluate pulmonary vascular changes, its potential to predict the long-term course after successful ventricular septal defect closure has not been proved. Operative lung biopsy slides obtained at the time of closure from 57 infants and children who had been among the first survivors (between 1954 and 1960) of such surgery were graded in blinded fashion according to the Heath-Edwards classification system, and the resultant biopsy grade of each was compared with the eventual long-term outcome of each child. In 53 (93%) of the 57 cases, the Heath-Edwards system correlated well with long-term clinical or hemodynamic status of the patient. Grade IV changes were predictive of a usually fatal outcome, while grade I and II changes were generally benign. Death from pulmonary vascular disease occurred, however, in four children whose operative lung biopsy had been classified as either grade I or II, indicating that the focal nature of the higher Heath-Edwards grades, or human error, must be considered when this classification system is employed.

Adolescent

Extraintestinal Campylobacter jejuni and Campylobacter coli infections: host factors and strain characteristics.

To determine whether extraintestinal isolates of Campylobacter jejuni and Campylobacter coli are the consequence of unusual host or bacterial characteristics, we studied clinical and bacteriologic features of 24 extraintestinal infections. Common serotypes and auxotypes were present among the extraintestinal isolates. Gastrointestinal isolates were more susceptible to normal human serum than were the systemic isolates; however, the ranges overlapped considerably. Predispositions to systemic spread were present in 52% of patients with extraintestinal infections; isolates from these patients were more often (73%) serum sensitive than were isolates from patients without predispositions (9%; P = .002). By sodium dodecyl sulfate-polyacrylamide gel electrophoresis, no specific protein band was associated with serum resistance, and all isolates of C. jejuni and C. coli had rough-type lipopolysaccharide profiles. Serum susceptibility was inversely correlated with carbohydrate or ketodeoxyoctonate (KDO) fraction of cell weight and directly correlated with KDO:carbohydrate ratio. Our results suggest that either host defects or specific bacterial virulence characteristics, such as serum resistance, possibly related to length of lipopolysaccharide side chain, may be responsible for extraintestinal infections due to C. jejuni and C. coli.

Adolescent

The first open heart corrections of tetralogy of Fallot. A 26-31 year follow-up of 106 patients.

Tetralogy of Fallot became a correctable malformation on August 31, 1954, and from that data through 1960, 106 patients (ages 4 months-45 years) who underwent open repairs at the University of Minnesota and were discharged, have been followed (99% complete) until death or for 26-31 years (mean: 23.7 years, 2424 patient years). The purposes of this study were to determine survival, morbidity, hemodynamics, educational/employment attainments, and relation of these to surgical technics. Operations were done by cross circulation (6 patients) and bubble oxygenator (100 patients). This group had the first uses of patch ventricular septal defect closure, outflow root, infundibuloplasty, atresia correction, ischemic arrests, and pacemakers among other innovations. Twenty-one (of 105 patients) have died during the followup: eight deaths in the first 10 years, 12 between 10 and 20 years, and 1 greater than 20 years. The causes of death were sudden (5), accidental (4), congestive failure (2), reoperation (2), suicide (2), and other (2). Actuarial survival at 30 years was 77%. Late complications were ten reoperations, five arrhythmias, and one endocarditis. Actuarial freedom from reoperations at 30 years was 91%. Cardiac recatheterizations in 62 patients disclosed only 10 with residual shunts. Peak right ventricular systolic pressures were less than 40 mmHg (34 patients), 41-60 mm (2 patients), 61-70 mm (4 patients), greater than 71 mm (4 patients). Thirty-four patients (32%) completed college, ten of these completed graduate school (5 masters degrees, 2 M.D.'s, 2 Ph.D.'s, 1 lawyer). Fifteen others attended college, and nine received technical school diplomas. Forty patients (18 men, 22 women) had progeny, with 82 (93%) live births and six major cardiac defects (7.3%). In summary, complete repair gave excellent late results in this group cared for very early in the open heart era. Survivors led productive lives without restrictions in education and employment. Many of the deaths/complications that occurred are now easily preventable, which augurs extremely well for this generation.

Adolescent

Involvement of zinc in the regulation of pHi, motility, and acrosome reactions in sea urchin sperm.

When sperm of Strongylocentrotus purpuratus or Lytechinus pictus are diluted into seawater, motility is initiated; and when exposed to egg jelly, an acrosome reaction is induced. In the presence of a variety of structurally different metal chelators (0.1-1 mM EDTA, EGTA, phenanthroline, dipyridyl, cysteine, or dithiothreitol), motility initiation is delayed and the acrosome reaction is inhibited. Of the metals detected in the sperm of these two species, very low levels of Zn+2 (0.1 microM free Zn+2) uniquely prevent this chelator inhibition. L. pictus sperm concentrate 65Zn+2 from seawater, and EDTA removes 50% of the accumulated 65Zn+2 by 5 min. Since both sperm motility and acrosome reactions are in part regulated by intracellular pH (pHi), the effect of chelators on the sperm pHi was examined by using the fluorescent pH sensitive probe, 9-aminoacridine, EDTA depresses sperm pHi in both species, and 0.1 microM free Zn+2 reverses this pHi depression. When sperm are diluted into media that contain chelators, both NH4Cl and monensin (a Na+/H+ ionophore) increase the sperm pHi and reverse the chelator inhibition of sperm motility and acrosome reactions. The results of this study are consistent with the involvement of a trace metal (probably zinc) in the pHi regulation of sea urchin sperm and indicate a likely mechanism for the previously observed effects of chelators on sperm motility and acrosome reactions.

2,2'-Dipyridyl

Use of auxotyping for epidemiological studies of Campylobacter jejuni and Campylobacter coli infections.

A chemically defined medium developed for Neisseria gonorrhoeae was modified to support the growth of Campylobacter jejuni and Campylobacter coli. A total of 76 isolates of C. jejuni and 14 isolates of C. coli were tested on this medium, which was designated Campylobacter defined medium (CDM), over a 3-month period. Although none of the C. coli isolates appeared to require amino acids, 51% of the C. jejuni tested required one and 7% required multiple amino acids for growth. An analysis of isolates obtained from three household outbreaks of campylobacteriosis demonstrated that auxotyping identified the epidemic strain within each outbreak. Among 70 isolates of C. jejuni examined, no correlation could be drawn between a specific serotype and auxotype or between auxotype and plasmid profile.

Amino Acids

Isoprenoid quinone content and cellular fatty acid composition of Campylobacter species.

A total of 36 strains of Campylobacter species were examined for isoprenoid quinones and cellular fatty acids. The isoprenoid quinone content was determined by reverse-phase high-pressure liquid chromatography, and the fatty acids were determined by capillary gas-liquid chromatography. All Campylobacter species contained menaquinone-6 (2-methyl-3-farnesyl-farnesyl-1,4-naphthoquinone) and a methyl-substituted menaquinone-6 (2,[5 or 8]-dimethyl-3-farnesyl-farnesyl-1,4-napthoquinone) as the major isoprenoid quinones. The latter menaquinone has not been reported in other bacteria and may prove to be a useful chemical marker of Campylobacter species. Campylobacter jejuni and most Campylobacter coli were distinguished from other campylobacteria by the presence of a C19 cyclopropane acid, and Campylobacter sputorum subsp. mucosalis differed from other species by the presence of lauric acid.

Campylobacter

Clinically mild tularemia associated with tick-borne Francisella tularensis.

Between May 9 and July 3, 1979, 12 cases of glandular or ulceroglandular tularemia occurred in residents of the Crow Indian Reservation in southcentral Montana; only 13 cases had been reported from this geographic area in the preceding 25 years. The illness was mild, characterized by fever and cervical or occipital adenopathy. Systemic symptoms were self-limited although residual lymphadenopathy was common. Francisella tularensis was isolated from ticks (Dermacentor variabilis), the suspected vector. The strains of F tularensis did not ferment glycerol and thus were identified as type B rather than the more virulent type A. None of 83 adults hospitalized in an urban area 50 miles from the reservation had agglutination titers of antibody to F tularensis of greater than or equal to 1:40 compared with eight of 77 patients at the reservation hospital (P less than 0.01). Mild tularemia in reservation residents may have gone unrecognized; similar illness due to type B F tularensis may occur elsewhere.

Adult

Calmodulin activates NAD kinase of sea urchin eggs: an early event of fertilization.

NAD kinase, one of the first enzymes activated after fertilization of sea urchin eggs, is regulated by Ca2+ and calmodulin in vitro. The evidence is the requirement for low amounts of Ca2+ (Kd for Ca2+ of 4 x 10(-7) M) and the dissociation of a heat-stable activator from the enzyme which is similar to calmodulin on the basis of radioimmunoassay, activation of bovine brain phosphodiesterase and coelectrophoresis of a major protein of the activator fraction with bovine calmodulin. Also, the calcium stimulation of the enzyme is prevented by trifluoperazine, an inhibitor of calmodulin-associated reactions. In vivo studies show that the enzyme is activated by artificial parthenogenesis regimes that increase cytosolic Ca2+, but not by ammonia activation which only partially activates eggs and bypasses the Ca2+-rise step. These in vitro and in vivo studies indicate that calmodulin is part of the linkage between the rise in Ca2+ at fertilization and the turning on of egg metabolism.

Animals