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Biomedical subjects

B A Jones

Publications and source records attributed to B A Jones.

At least 55 records · Page 3Linked to original sources
PubMed1995

Can mammography screening explain the race difference in stage at diagnosis of breast cancer?

BACKGROUND: A race difference in the stage at diagnosis of breast cancer is well established: African American women are less likely than white women to be diagnosed at a localized stage. The purpose of this study was to determine the extent to which the observed race (black/white) difference in stage at diagnosis of breast cancer could be accounted for by race differences in the mammography screening history. METHODS: This was a population-based, retrospective study of 145 African American and 177 white women with newly diagnosed breast cancer in Connecticut, between January, 1987 and March, 1989. Cases were ascertained through active surveillance of 22 Connecticut hospitals. RESULTS: Black women were diagnosed more commonly with later stage cancer (TNM stage > or = II) (age-adjusted odds ratio [OR] = 2.01, 95% confidence interval [CI] 1.24-3.24) than were white women. Blacks were also more likely than whites to report that they had not received a mammogram in the 3 years before development of symptoms or diagnosis (OR = 2.05, 95% CI 1.26-3.35); this association was not altered substantially with adjustment for socioeconomic status. In race-specific analyses, mammography was protective against later stage diagnosis in white women, but not in black women. With adjustment for mammography screening, the OR for the race-stage association was reduced only minimally, and race remained a significant predictor of stage at diagnosis. CONCLUSIONS: In these population-based data, history of mammography screening was not an important explanatory variable in the race-stage association. Specifically, history of mammographic screening accounted for less than 10% of the observed black/white difference in stage at diagnosis of breast cancer.

Adult↗
PubMed1995

The protective effect of vein cuffed anastomoses is not mechanical in origin.

PURPOSE: Intimal hyperplasia (IH) is a proliferative process of vascular smooth muscle cells that occurs after an arterial injury, particularly at outflow anastomoses of prosthetic bypass grafts. IH causes stenosis that leads ultimately to graft flow reduction and thrombosis. We have demonstrated previously that vein cuff interposition between an expanded polytetrafluoroethylene (e-PTFE) graft and artery at distal anastomoses diminished IH formation in the arterial outflow as compared with noncuffed anastomoses. Improved long-term patency rates associated with the placement of an interposition vein cuff at the distal anastomosis of e-PTFE grafts to infrageniculate arteries have also been demonstrated clinically. This study examined the mechanical factors that may contribute to the protective effect of cuffed anastomoses. These factors include the expansibility of the vein cuff as compared with e-PTFE, as well as the angle of the cuffed anastomosis. METHODS: Compatible animals were selected by use of platelet aggregation studies. Nine dogs, group A, received a 4 mm e-PTFE graft plus a 1 cm long interposition vein cuff at the distal anastomosis in the left carotid artery. The same procedure was done on the right side, and in addition the vein cuff was encircled by an e-PTFE jacket incorporated into the anastomosis to prevent the expansion of the vein cuff with arterial pulsation. To study the effect of distal anastomotic angle and geometry on the formation of IH, five dogs, group B, received a 4 mm e-PTFE graft in both sides. On the left, the distal anastomosis was performed between the graft and the artery at an acute angle as it is commonly done when a bypass graft is placed. On the right side a 1 cm long, 6 mm diameter e-PTFE segment was interposed between the artery and the graft at a perpendicular angle. This geometry mimicked the right angle of a vein cuff-to-artery anastomosis. After 10 weeks the grafts were harvested, and the thickness of IH was measured with an ocular micrometer under light microscopy. RESULTS: In group A, one dog had bilateral graft thrombosis (12%), and these grafts were discarded. In the remaining eight dogs there was no statistically significant difference in the thickness of IH between the right (jacketed group) and the left side (nonjacketed/control group), showing that vein cuff expansibility did not play a role in protecting against the formation of IH. In group B, bilateral graft thrombosis occurred in four of five dogs (80%), suggesting that the perpendicular anastomotic angle was not protective. CONCLUSION: These results suggested that the protective effect of the vein cuff is not mechanical in origin.

Anastomosis, Surgical↗
PubMed1995

Rescreening in gynecologic cytology. Rescreening of 3762 previous cases for current high-grade squamous intraepithelial lesions and carcinoma--a College of American Pathologists Q-Probes study of 312 institutions.

OBJECTIVE: To quantitate, characterize, and analyze errors identified in the rescreening of previous gynecologic cytology specimens with original diagnoses of "within normal limits" or "benign cellular changes" for current cases diagnosed as carcinoma or high-grade squamous intraepithelial lesion. DESIGN AND SETTING: College of American Pathologists Q-Probes laboratory quality improvement study in 312 laboratories. MAIN OUTCOME MEASURE: False-negative rate in cases rescreened as a result of a current cytologic diagnosis of carcinoma or high-grade squamous intraepithelial lesion. RESULTS: During the examination and reporting of 1,741,515 current Papanicolaou smear cases, participating laboratories rescreened a total of 3762 previous cases that were originally diagnosed, during the 5 years prior to the current case, as being within normal limits or having benign cellular changes. For the rescreened cases, the overall false-negative rates were 10.1% using a narrow definition and 19.7% using a broad definition. The majority of errors for cases originally diagnosed as within normal limits were screening errors, while interpretive errors predominated in those cases originally diagnosed as having benign cellular changes. Eighty-six percent of all false negatives were identified in those previous cases that were originally diagnosed and reported in the 3 years prior to the current case. CONCLUSIONS: Rescreening of previously reported smears, in patients with current abnormal findings, as one component of a complete quality improvement program, identifies errors that may provide information that will enable a laboratory to improve future performance.

Carcinoma↗
PubMed1995

Complete blood count specimen acceptability. A College of American Pathologists Q-Probes study of 703 laboratories.

OBJECTIVE: to determine the frequency and reasons for rejection of specimens submitted to the laboratory for complete blood count studies. DESIGN AND SETTING: College of American Pathologists' Q-Probes laboratory quality improvement study prospective recording of rejected complete blood count specimens and associated factors in 703 laboratories. MAIN OUTCOME MEASURE: Percentage of submitted specimens rejected for testing. RESULTS: Of 7,894,882 complete blood count specimens submitted for testing to the participating laboratories during the data collection period, 35,347 (0.45%) were rejected. The most frequent reason for rejection was a clotted specimen, which occurred about six times more frequently than the second most cited reason, insufficient specimen quantity. Compared with their respective frequency of use for specimen collection, significantly more rejected specimens were collected in microtubes than in other containers. Compared with the respective frequency with which they collect specimens, laboratory personnel had significantly fewer rejected specimens than the other personnel groups. The poorest performance was exhibited by other in-hospital nonlaboratory personnel. Hospital bedsize was also a significant performance factor; smaller hospitals demonstrated lower rejection percentages. CONCLUSIONS: Specimen rejection should be monitored on a regular basis, identifying institution-specific factors that are associated with rejection. Monitoring of sufficient significant variables will help narrow the focus of corrective action. Action thresholds should be set sufficiently low to assure ongoing efforts toward improvement.

Blood Cell Count↗
PubMed1994

Testing at the patient's bedside.

Performing laboratory tests at the patient's bedside has become a popular component of care, primarily because of the immediate availability of test results. Bedside glucose monitoring programs have been the prototype for bedside testing and have provided the most experience in this area. Studies of bedside glucose testing have shown that in order to obtain reliably accurate results, there must be a well-designed and well-implemented quality assurance program, which should involve laboratory professionals. However, medical necessity, cost, and alternatives should be thoroughly considered before beginning a bedside testing program, as well as the commitment to a strong quality assurance program.

Blood Glucose↗
PubMed1993

Bedside glucose monitoring. A College of American Pathologists Q-Probes study of the program characteristics and performance in 605 institutions.

In 1991, the College of American Pathologists' Q-Probes quality improvement program studied precision, accuracy, and program characteristics of bedside glucose monitoring (BGM) in 605 institutions. Precision measurements made in 569 institutions were based on 15,950 quality control results. Precision, expressed as a percentage coefficient of variation, was less than 10 in almost 90% of the institutions. For accuracy, 4517 BGM results from 181 institutions were compared with clinical laboratory glucose results. Approximately 58% of BGM results were within +/- 10% and 75% of BGM results were within +/- 15% of the corresponding clinical laboratory results. Program characteristics associated with better performance were (1) laboratorian program responsibility, laboratorian BGM test performance, and laboratorian involvement in training; (2) a policy requiring repeated scheduled operator training and/or performance review; (3) use of an internal comparison program; and (4) participation in an external proficiency testing program. We conclude that BGM frequently does not meet quality goals and provide recommendations on how BGM programs can be improved.

Australia↗
PubMed1992

Mitochondrial DNA maintenance in yeast requires a protein containing a region related to the GTP-binding domain of dynamin.

Nuclear gene products replicate and partition mitochondrial DNA (mtDNA) molecules in the yeast Saccharomyces cerevisiae. However, few of the relevant genes have been identified. A mutation that results in temperature-sensitive loss of mtDNA identifies one of these genes, MGM1. Deletion of MGM1 shows that aside from its role in the mitochondrion, the gene has no essential cellular function. The MGM1 protein has a 200-amino-acid region that is highly related to a family of GTP-binding proteins of apparently diverse function that includes the microtubule-binding protein, dynamin D100. The temperature-sensitive strain partitions mtDNA molecules at the restrictive temperature, but a defect in mtDNA synthesis results in a reduction in the number of molecules per cell at each cell division. On the basis of the results of this study, we conclude that cells can partition single mitochondrial genomes, and that when a cell receives a single molecule at division it is able to restore the normal complement of multiple copies.

Amino Acid Sequence↗
PubMed1991

Selection and application of Streptococcus bovis as a silage inoculant.

Three strains of Streptococcus bovis, a homolactic bacterium capable of utilizing starch, were evaluated for growth kinetics and ability to decrease the pH of alfalfa silage. A selected strain was evaluated for its competitiveness as an inoculant with Enterococcus faecium, an organism used in inoculants, and for its ability to enhance the effect of a commercial inoculant. Testing was completed over three studies using wilted alfalfa (28 to 34% dry matter) ensiled into laboratory silos. Treatments were control, E. faecium, E. faecium and commercial inoculant, S. bovis, and S. bovis and commercial inoculant. Replicate silos were emptied and analyzed at 0.5, 1, 2, 4, 8, and 40 days for pH, fermentation products, and nitrogen fractions. S. bovis alone lowered the pH quicker and improved silage parameters early in the fermentation compared with E. faecium, the commercial inoculant, and control treatments. When combined with a commercial inoculant, S. bovis lowered pH more quickly than the commercial inoculant alone and E. faecium plus commercial inoculant. At 40 days, S. bovis combination had lower pH and ammonia nitrogen and acetate contents than the E. faecium combination. Starch in the silage was not utilized by S. bovis as had been anticipated. Results indicate that S. bovis was more effective than E. faecium as a silage inoculant and could enhance a commercial inoculant on low-dry-matter alfalfa.

Colony Count, Microbial↗
PubMed1989

New epidemiologic evidence confirming that bias does not explain the aspirin/Reye's syndrome association.

To determine the validity of the aspirin/Reye's syndrome association, we developed an epidemiologic investigation to assess the effects of five potential sources of bias. A case-control study incorporated procedures to avoid temporal precedence and susceptibility bias. These included classifying cases as having monophasic or biphasic patterns of illness and matching for severity of symptoms at zero-time. To evaluate the effect of a potential recall bias, an "alternate-condition" control group was enrolled. A medical record review study was conducted to assess the potential for diagnostic bias, and a blanket surveillance of all hospitals in a region was conducted to evaluate reporting bias. Twenty-four case subjects and 48 matched controls were enrolled. Eight-eight percent of case subjects and only 17% of controls had received aspirin prior to the onset of Reye's syndrome (matched odds ratio, 35; 95% confidence interval, 4.2 to 288). Further analyses demonstrated that the association could not be attributed to the five potential sources of bias.

Adolescent↗
PubMed1988

Degradation of methionine hydroxy analog in the rumen of lactating cows.

Four lactating cows fitted with T-type cannulae in the proximal duodenum were utilized in a 4 X 4 Latin square design to study rumen microbial degradation of methionine hydroxy analog, a methionine supplement. A diet consisting of 55% concentrate and 45% corn silage was fed ad libitum four times daily. The four treatments were 1) control, no methionine hydroxy analog, 2) methionine hydroxy analog in the form of a calcium salt, 3) methionine hydroxy analog in the acid form, and 4) DL-methionine. The amino acids were incorporated into a grain mix, which was top-dressed. All diets were isonitrogenous. Twelve samples of duodenal digesta and fecal matter were collected during the last 3 d of each of the four 14-d periods. Samples were composited for analysis. Microbes either altered or degraded 99% of the methionine hydroxy analog in the rumen, since recovery of the analog in duodenal digesta was less than 1% of the amount fed for both the acid form and the calcium salt.

Animals↗
PubMed1987

Common pancreaticobiliary channels and their relationship to gallstone size in gallstone pancreatitis.

Bile reflux into the pancreatic duct after impaction of a stone in a common pancreaticobiliary channel has been suggested to be the initiating factor in gallstone pancreatitis. Such reflux would require that the impacted stone be smaller than the length of the common channel. The incidence of common channels was studied and gallstone size was compared with common channel length in patients with gallstone pancreatitis and those with cholelithiasis or choledocholithiasis without pancreatitis. Sixty-seven per cent of patients with gallstone pancreatitis had a common channel present on intraoperative cholangiography versus 32% of patients with cholelithiasis or choledocholithiasis without pancreatitis (p less than 0.005). Common channel length was greater than the diameter of the smallest stone in nine of 27 patients with gallstone pancreatitis and in 13 of 109 patients with cholelithiasis or choledocholithiasis without pancreatitis (p less than 0.025). In conclusion, common channels are more frequent in patients with gallstone pancreatitis than in patients with other biliary tract disease. Furthermore, gallstone pancreatitis is associated with stones that are smaller than the common channel, which favors obstruction of both pancreatic and bile ducts while allowing reflux of contents between them.

Cholangiography↗
PubMed1986

Mucinous carcinoid tumor of the appendix presenting as bilateral ovarian tumors.

Mucinous carcinoid tumor of the vermiform appendix, an uncommon variant of appendiceal carcinoid, may present clinically with ovarian metastases. We studied a tumor by immunohistochemistry and electron microscopy and reviewed eight similar cases from the literature. The primary and metastatic tumors in our case were composed of mucin-producing cells and small argyrophilic cells arranged in cords and acini. Tumor cells in both primary and metastatic sites exhibited identical patterns of immunoreactivity for epithelial antigens (epithelial membrane antigen, carcinoembryonic antigen) and neuroendocrine antigens (serotonin, vasoactive intestinal polypeptide, adrenocorticotropic hormone). Ultrastructurally, the cells contained either mucin vacuoles or dense-core neurosecretory granules; rare individual cells contained both types of inclusions. When bilateral solid mucinous ovarian tumors are discovered at laparotomy, diagnostic appendectomy is indicated if no obvious extraovarian primary tumor can be found.

Adrenocorticotropic Hormone↗
PubMed1986

Minimal renal amyloidosis with nephrotic syndrome.

Two patients older than age 50 years had minimal amyloidosis in association with the nephrotic syndrome. The amyloid deposits in each case were so inconspicuous as to have been initially overlooked, and both biopsy specimens were thought to show minimal glomerular changes. A few, widely scattered, silver-positive, epimembranous spicules were found on reexamination by light microscopy, and Congo red and thioflavin T stains and electron microscopy confirmed the presence of small glomerular amyloid deposits. Both patients have since died of renal failure. In our series of biopsy specimens, amyloidosis was found in 14.2% of patients older than age 50 years presenting with nephrotic syndrome or severe proteinuria, over 1 1/2 times the frequency of minimal-change nephrotic syndrome. We therefore urge careful examination for amyloid deposits of all kidney biopsy specimens with the appearance of minimal-change nephrotic syndrome in older patients. Fluorescence microscopy of Congo red- and thioflavin T-stained sections is very helpful in the detection of small deposits.

Amyloidosis↗
PubMed1986

Vertical banded gastroplasty: results in 233 patients.

The authors describe their experience with vertical banded gastroplasty in 233 patients for whom the follow-up ranged from 12 to 30 months. There were no deaths. Intraoperatively, two gastric perforations and one esophageal perforation occurred; these were closed and drained. A postoperative leak was treated promptly by removal of the collar, drainage and gastrostomy. There were three instances of late obstruction, due in one to mesh adhering to liver and in two to stenoses; gastrogastrostomy was followed by regained weight. Removal of the collar was also associated with failure to lose adequate weight. Rare complications were intraluminal erosion of mesh and staple-line breakdown. The gallbladder was still present in 175 patients; of these, 25 had gallstones and underwent a cholecystectomy at the time of gastroplasty. Of the other 150, symptomatic gallstones subsequently developed in 13. At 12 months after gastroplasty 80% of patients had lost at least 50% of excess weight and at 24 months 83% had lost 50% or more of excess weight (15 patients lost to follow-up). To avoid failures, the collar circumference should not be more than 5.0 cm. A small experience suggests that revision of a failed horizontal gastroplasty to vertical banded gastroplasty is hazardous.

Adolescent↗
PubMed1985

Periampullary tumors: which ones should be resected?

Resection was carried out in 118 patients for periampullary lesions. Ninety-eight of these were adenocarcinomas and were treated by the Whipple operation, total pancreatectomy, or local resection (87 patients, 7 patients, and 4 patients, respectively). Diagnosis of pancreatic head carcinoma before resection was falsely positive in 27 percent of the patients. Mortality for radical resection was 4 percent. Five year survival for ampullary carcinoma was 32 percent, and for pancreatic head carcinoma it was 7 percent. Resection of all periampullary tumors is recommended, with the Whipple operation being the standard in most cases.

Actuarial Analysis↗