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Biomedical subjects

B A Jones

Publications and source records attributed to B A Jones.

At least 19 recordsLinked 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↗
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↗
PubMed1985

The prevalence of appendiceal fecaliths in patients with and without appendicitis. A comparative study from Canada and South Africa.

Appendicitis is more common in developed than in developing societies and appendiceal fecaliths are thought to have an etiologic role in the disease. The geographic distribution of appendiceal fecaliths was investigated by systematic, intraoperative palpation of the appendix in patients in Toronto, Canada and Johannesburg, South Africa. The incidences of fecaliths found on pathologic sectioning of the appendix in appendicitis patients in both societies were compared. In the Canadian population, the prevalence of fecaliths in patients whose appendices were palpated incidentally was 32% versus 52% for those with appendicitis (p less than 0.01). In the African population, the prevalence of fecaliths in patients whose appendices were palpated incidentally was four per cent versus 23% for those with appendicitis (p = 0.04). The difference in prevalence of incidental appendiceal fecaliths in the two populations was statistically significant (p less than 0.005). The prevalence of fecaliths is higher in developed countries, such as Canada, than in developing countries, such as Africa, and is also higher in patients with than in those without appendicitis. These data support the theory that the low-fiber diets consumed in developed countries lead to fecalith formation, which then predisposes to appendicitis.

Adolescent↗
PubMed1985

Transluminal angioplasty: results in high-risk patients with advanced peripheral vascular disease.

The role of percutaneous transluminal angioplasty in treating advanced peripheral vascular disease is unknown. The authors therefore reviewed the experience of Sunnybrook Medical Centre in Toronto with 85 consecutive patients who had rest pain, ulceration, pregangrene or gangrene as a result of peripheral vascular disease and who underwent percutaneous transluminal angioplasty. Seventy-four percent were smokers and 91% were at increased risk due to one or more of the following: coronary or cerebral ischemic disease, diabetes mellitus, obesity and hypertension. Thirty-six patients underwent dilatation of iliac lesions, 46 of superficial femoral or popliteal and 3 of more distal lesions. In nine patients angioplasty was repeated on the same lesion. In 16 patients, the procedure was technically unsatisfactory. The morbidity and 30-day mortality were 5% and 2%, respectively. When the procedure was technically satisfactory, surgery was avoided and the limb was salvaged at 1, 2 and 5 years in 69%, 62% and 54% of cases, respectively (life-table analysis). The authors conclude that percutaneous transluminal angioplasty is acceptable treatment for patients with advanced peripheral vascular disease, because the morbidity and mortality are low and the long-term results are good.

Adult↗
PubMed1983

Bromine levels in tissue lipids of rats fed brominated fatty acids.

Rats have been fed diets containing either 0.8% brominated corn oil or 0.5% of the ethyl ester of 9,10-dibromostearate or 9,10,12,13-tetrabromostearate. The brominated compounds were incorporated into semisynthetic diets and animals were observed after feeding periods of 5 days to 3 months. With the exception of adipose tissues, the highest concentration of lipid-bound bromine was observed after 5 days on the experimental diets. It was also observed that feeding of the dibromostearate resulted in the highest levels of lipid-bound bromine in heart, whereas the tetrabromostearate tended to result in higher levels of lipid-bound bromine in liver. Brominated corn oil produced more substantial changes than the brominated fatty acid esters, inducing fatty livers and enlarged yellow hearts. Microscopic examination indicated myocardial degeneration and occasional early necrosis.

Animals↗