shukoor65/lab-rag-model huggingface dataset:
Smoking and mortality among older men and women in three communities. BACKGROUND. Although cigarette smoking is the leading avoidable cause of premature death in middle age, some have claimed that no association is present among older persons. METHODS. We prospectively examined the relation of cigarette-smoking habits with mortality from all causes, cardiovascular causes, and cancer among 7178 persons 65 years of age or older without a history of myocardial infarction, stroke, or cancer who lived in one of three communities: East Boston, Massachusetts; Iowa and Washington counties, Iowa; and New Haven, Connecticut. At the time of the initial interview, prevalence rates of smoking in the three communities ranged from 5.2 to 17.8 percent among women and from 14.2 to 25.8 percent among men. During five years of follow-up there were 1442 deaths, 729 due to cardiovascular disease and 316 due to cancer. RESULTS. In both sexes, rates of total mortality among current smokers were twice what they were among participants who had never smoked. Relative risks, as adjusted for age and community, were 2.1 among the men (95 percent confidence interval, 1.7 to 2.7) and 1.8 among the women (95 percent confidence interval, 1.4 to 2.4). Current smokers had higher rates of cardiovascular mortality than those who had never smoked (as adjusted for age and community, the relative risk was 2.0 [95 percent confidence interval, 1.4 to 2.9] among the men and 1.6 [95 percent confidence interval, 1.1 to 2.3] among the women), as well as increased rates of cancer mortality (relative risk, 2.4 [95 percent confidence interval, 1.4 to 4.1] among the men and 2.4 [95 percent confidence interval, 1.4 to 3.9] among the women). In both sexes, former smokers had rates of cardiovascular mortality similar to those of the participants who had never smoked, regardless of age at cessation, whereas the rates for all cancers, as well as smoking-related cancers, remained elevated among men who had once smoked. CONCLUSIONS. Our prospective findings indicate that the mortality hazards of smoking extend well into later life, and suggest that cessation will continue to improve life expectancy in older people.
Human papillomavirus type-related DNA and c-myc oncogene alterations in colon cancer cell lines. Although squamous-cell epithelium is the most frequent target site of human papillomavirus (HPV) infection, a similar infection is demonstrated in columnar epithelial cells in this paper. The papillomavirus expression in three cell lines was detected in colorectal adenocarcinoma of Chinese patients. The HPV-16 and HPV-18 DNA sequences were found in colorectal cancer cell lines, which might suggest the correlation of HPV to the etiology of colorectal cancers. In addition, c-myc oncogene was identified by amplification in all three colorectal cancer cell lines, but only normal germ-line fragments were found in control tissue. The correlation between HPV and c-myc, and the implications of these findings in colorectal cancers are also discussed.
Parathyroiditis associated with hyperparathyroidism and branchial cysts. A 57-year-old man had renal stones, and biochemical investigation led to a diagnosis of primary hyperparathyroidism. Surgical exploration revealed bilateral inferior parathyroid enlargement. Both glands were removed; macroscopically, small cysts were seen on cut sections. Histologic examination showed broad bands of fibrosis, lymphoid follicles, and plasma cells that diffusely effaced the parathyroid architecture. Such features--if seen in the thyroid gland--would be reminiscent of an autoimmune process. The cysts were lined by respiratory and squamous epithelia and contained lymphoid follicles in their walls. Less affected areas of the parathyroid tissue were hyperplastic. It is believed that the inflammatory response in the parathyroid glands that is described in this article may be characteristic. It may result from the cysts or their contents or from an autoimmune reaction.
Intraoperative ultrasonography: an important surgical adjunct for intramedullary tumors. The echographic characteristics of 186 suspected intramedullary spinal cord tumors were reviewed. Ultrasonography was found to be specific in distinguishing the tumor type, the extent of the lesion, and the presence and type of associated cysts. Ultrasonography greatly facilitates the selection of respective sites for the placement of a myelotomy, and for initiation of the resection. Additionally, this indispensable adjunct provides ongoing images that allow the preoperative plan to be precisely followed in a surgical field where anatomical landmarks are limited and the margin for error is minimal.
Molecular basis of the enhanced susceptibility of the erythrocytes of paroxysmal nocturnal hemoglobinuria to hemolysis in acidified serum. When incubated in acidified serum, the erythrocytes of paroxysmal nocturnal hemoglobinuria (PNH) are hemolyzed through activation of the alternative pathway of complement (APC), but normal erythrocytes are resistant to this process. PNH cells are deficient in decay-accelerating factor (DAF), a complement regulatory protein that inhibits the activity of both the classical and the alternative pathways. However, deficiency of DAF alone does not account entirely for the aberrant effects of acidified serum on PNH cells. Recently, we have shown that PNH erythrocytes are also deficient in another complement control protein called membrane inhibitor of reactive lysis (MIRL) that restricts complement-mediated lysis by blocking formation of the membrane attack complex (MAC). To determine the effects of the DAF and MIRL on susceptibility to acidified serum lysis, PNH cells were repleted with the purified proteins. DAF partially inhibited acidified serum lysis by blocking the activity of the amplification C3 convertase. MIRL inhibited acidified serum lysis both by blocking the activity of the MAC and by inhibiting the activity the C3 convertase. When DAF function was blocked with antibody, normal erythrocytes became partially susceptible to acidified serum lysis. By blocking MIRL, cells were made completely susceptible to lysis, and control of C3 convertase activity was partially lost. When both DAF and MIRL were blocked, the capacity of normal erythrocytes to control the activity of the APC and the MAC was destroyed, and the cells hemolyzed even in unacidified serum. These studies demonstrate that DAF and MIRL act in concert to control susceptibility to acidified serum lysis; of the two proteins, MIRL is the more important. In addition to its regulatory effects on the MAC, MIRL also influences the activity of the C3 convertase of the APC. Further, in the absence of DAF and MIRL, the plasma regulators (factor H and factor I) lack the capacity to control membrane-associated activation of the APC.
Prevention of heterotopic ossification in high-risk patients by radiation therapy. Heterotopic ossification (HO) is a frequent occurrence after cemented and cementless total hip arthroplasty (THA). Patients at risk for this complication include those with preexisting ipsilateral or contralateral HO, diffuse idiopathic skeletal hyperostosis, hypertrophic osteoarthrosis, posttraumatic arthritis, and ankylosing spondylitis. Low-dose radiation therapy effectively prevents HO in this high-risk group when treatment is begun early in the postoperative period. A prospective evaluation has established the efficacy of fractionated and single-dose radiation therapy protocols. Limited radiation portals are used in patients receiving cementless prostheses. A rectangular radiation portal obliquely oriented to the prosthesis enables radiation treatment of the periarticular soft tissues while avoiding exposure of the bone-prosthesis interface. Radiation therapy to this interface may inhibit or delay bony ingrowth. Radiation therapy is the only treatment used to prevent HO that is delivered locally and not systemically. Low-dose radiation therapy using a limited radiation portal is the treatment of choice to prevent HO in high-risk patients after cementless THA.
Demonstration of osteonectin mRNA in megakaryocytes: the use of the polymerase chain reaction. Platelets have been shown to release osteonectin on thrombin stimulation. The origin of platelet osteonectin was unclear as it may have been synthesized by megakaryocytes or it may have been endocytosed from plasma as other platelet alpha-granule constituents are. Platelet osteonectin has a larger apparent molecular size than the bone species, although the molecular basis for this difference has not been elucidated. These two issues have been addressed here by (1) examining the potential for osteonectin biosynthesis in human megakaryocytes by demonstrating the presence of osteonectin mRNA in purified megakaryocytes, and (2) comparing the coding portion of osteonectin transcript in megakaryocytes to the size of its bone counterpart. Because of the limitations of cell population purity and in obtaining sufficient numbers of megakaryocyte cells for Northern analysis, we have used the polymerase chain reaction (PCR) to detect the presence of human osteonectin mRNA in megakaryocyte and megakaryocyte-depleted bone marrow cells. Isolation of RNA, cDNA synthesis, and PCR were performed on human osteosarcoma SaOS-2 cells, enriched megakaryocytes, and megakaryocyte-depleted cells. Restriction enzyme analysis of PCR DNA products confirmed the identity of the products as those encoding osteonectin for all three cell populations studied. In addition, the sizes of DNA indicate that osteonectin genomic DNA, nuclear RNA, or altered transcript were not amplified, and that the transcript from megakaryocytes is the same size as that from bone cells. These data suggest that the difference in protein size between platelet and bone osteonectin is due to posttranslational modification. To overcome the possibility that megakaryocyte signal originated from contaminating cells (less than 5% by cell count), all three cell populations were diluted to less than one cell per tube and PCR amplification was performed. Limiting dilution analyses demonstrated the presence of osteonectin mRNA in single megakaryocytes as well as in single cells from the cell population depleted of megakaryocytes, suggesting the capacity for osteonectin biosynthesis in all cells studied. The procedure we describe in this report can be used to examine specific characteristics of mRNA molecules in heterogeneous cell populations and in situations where only small quantities of cells can be obtained.
The double-balloon and Inoue techniques in percutaneous mitral valvuloplasty: comparative results in a series of 232 cases. Immediate hemodynamic results of percutaneous mitral valvuloplasty were compared in two consecutive series of unselected patients from the same institution undergoing valvuloplasty with the double-balloon (161 patients) or the Inoue balloon (71 patients) technique. Before valvuloplasty, the patient series were comparable with regard to average age, gender repartition and most clinical, electrocardiographic, X-ray and hemodynamic variables. Poor anatomic forms of mitral stenosis were equally distributed in both series (41% vs. 45%, p = NS). The magnitude of mitral valve area increase and of mean mitral gradient decrease during percutaneous mitral valvuloplasty did not differ significantly in the Inoue balloon and double-balloon series (mean +/- SEM 1.1 +/- 0.2 to 1.95 +/- 0.5 and 1.0 +/- 0.2 to 1.97 +/- 0.5 cm2, respectively, for mitral valve area and 12 +/- 3 to 5 +/- 2 and 13 +/- 4 to 5 +/- 2 mm Hg, respectively, for mean mitral gradient). Four cases of 3+ mitral regurgitation occurred in the Inoue balloon series and 7 in the double-balloon series (p = NS). A good immediate result--defined as mitral valve area greater than or equal to 1.5 cm2 with greater than or equal to 25% in mitral valve area gain and mitral regurgitation less than 2+ at the end of the procedure--was observed in 78% of patients in both series. Three cases of tamponade due to chamber perforation and 14 cases of transient air embolism in the right coronary system due to balloon rupture were observed in the double-balloon series.
Mutational analysis of an archaebacterial promoter: essential role of a TATA box for transcription efficiency and start-site selection in vitro. By using a recently developed in vitro transcription assay, the 16S/23S rRNA-encoding DNA promoter from the archaebacterium Sulfolobus sp. B12 was dissected by deletion and linker substitution mutagenesis. The analysis of 5' and 3' deletion mutants defined a core promoter region between positions -38 and -2 containing all information for efficient and specific transcription. Further characterization of this region by linker substitution mutagenesis indicated two sequence elements important for promoter function--one located between positions -38 and -25 (distal promoter element) and the other one located between positions -11 and -2 (proximal promoter element). The distal promoter element encompassed the TATA-like "box A" element located approximately 26 nucleotides upstream of the majority of transcription start sites in archaebacteria (Archaeobacteria). All mutations within this box A motif virtually abolished promoter function. Complete inactivation of the proximal promoter element was dependent on extensive mutagenesis; this element is not conserved between archaebacterial promoters except for a high A + T content in stable RNA gene promoters from Sulfolobus. Mutants containing insertions or deletions between the distal and proximal promoter elements were only slightly affected in their transcription efficiency but displayed a shift in their major initiation site, retaining an essentially fixed distance between the distal promoter element and the transcription start site. Thus, efficient transcription and start-site selection were dependent on a conserved TATA-like sequence centered approximately 26 nucleotides upstream of the initiation site, a situation unlike that of eubacterial promoters but resembling the core structure of most eukaryotic RNA polymerase II (and some RNA polymerase III) promoters. This finding suggests a common evolutionary origin of these promoters consistent with the known similarities between archaebacterial and eukaryotic RNA polymerases.
Decreased CD45RA T cells in B-cell chronic lymphatic leukemia patients: correlation with disease stage. T-cell subsets CD4, CD8 and suppressor-inducers (CD45RA) were determined in 20 patients with B-cell chronic lymphatic leukemia (B-CLL). The proportion of CD4 and CD45RA was decreased when compared with T cells from normal subjects. CD8 was markedly increased. The activity of concanavalin A-induced suppressor cells was not significantly different from that of normal controls and was negatively correlated to the percentage of CD4 of B-CLL patients. The selective loss of CD45RA cells was more prominent in patients in advanced Rai stages of the disease (III to IV) than in early stages (0 to II). Six patients of the advanced stages group suffered from autoimmune hemolytic anemia, whereas no patient in the early stages of disease showed an autoimmune phenomenon. Our results may indicate a mechanism of autoimmunity in B-CLL similar to that of patients with autoimmune diseases.
Role of endoscopic retrograde cholangiopancreatography after orthotopic liver transplantation. Twelve of 178 (7%) liver transplant patients underwent endoscopic retrograde cholangiopancreatography (ERCP) after transplantation. The indications for ERCP were persistent or late onset cholestasis, recurrent cholangitis, and suspected biliary leaks or strictures. The time between transplantation and ERCP ranged from 44 to 330 days (median 153 days). Biliary complications diagnosed by ERCP included biliary sludge in the form of casts, calculi, or debris (n = 7); bile leaks (n = 2); a biliary stricture (n = 1), and complete biliary obstruction (n = 1). One patient had a normal cholangiogram after transplantation. Biliary sludge was detected by ultrasound before ERCP in only one of six patients. Eight patients underwent endoscopic papillotomy, followed by clearance of biliary sludge in four and dilatation of a biliary stricture in one. Two patients bled after papillotomy but neither required surgical intervention. At a median follow up of 1.2 years (range 0.5-2.8 years), nine patients are well and three have died. ERCP provides both accurate diagnosis of biliary complications after liver transplantation and treatment that obviates the need for additional surgery in selected patients.
The JH/LVOH method in the quantification of aortic regurgitation: how the cardiac sonographer may avoid an important potential pitfall. Color flow Doppler allows for methods in which to quantitate the severity of valvular regurgitation. In particular, the regurgitant jet height/left ventricular outflow tract height (JH/LVOH) method of quantitating the severity of aortic regurgitation has been validated and is routinely used in the adult echocardiography laboratory. A potential pitfall exists in the measurement of the LVOH. This article points out this potential source of error and, in addition, proposes steps that may be taken by the cardiac sonographer to avoid this potential measurement pitfall.
The double-stapled ileal reservoir and ileoanal anastomosis. A prospective review of sphincter function and clinical outcome. Fifteen consecutive patients (nine males and six females) who underwent construction of a double-stapled ileoanal reservoir (DS-IAR) were prospectively evaluated. Mean and maximal resting pressures preoperatively, before ileostomy closure, and at 12 months, were 53 and 84 mm Hg, 39 and 62 mm Hg, and 62 and 81 mm Hg. Mean and maximal squeeze pressures at those same time periods were 96 and 153 mm Hg, 111 and 173 mm Hg, and 95 and 168 mm Hg. There were no significant decreases in either resting or squeeze pressure between preoperative values and those obtained 12 months after surgery. However, the length of the high pressure zone decreased from 3.8 cm preoperatively to 2.3 cm at 12 months. This reflects the sacrifice of the cephalad 1.5 cm of the internal anal sphincter necessary to effect this anastomosis at a mean of 1.4 cm from the dentate line. However, this maneuver did not result in poor continence. Eleven patients whose ileostomies were closed for a mean of 9 months, ranging from 3 to 15 months, were evaluated regarding functional outcome. Only one patient had any incontinence and this patient had incomplete circular-stapled tissue rings, which necessitated transanal suture repair of the anastomotic defect. Similarly, three of the four patients who sometimes or rarely use a pad at night had transanal-suture reinforcement. Ten of the 11 patients never wear a pad during the day. No pelvic or perianal sepsis occurred. Stratified squamous epithelium was found in 6 of the 13 distal stapler "donuts" that were examined. In addition, 10 patients underwent biopsy of the tissue immediately caudad to the circular staple line at the time of ileostomy closure; in five, only stratified squamous epithelium was noted. The DS-IAR is associated with excellent objective physiologic and subjective functional results.
Adverse effect of therapeutic vasoconstrictors in experimental acute pancreatitis. Alpha-adrenergic drugs commonly are used to treat hypotension resulting from severe acute pancreatitis. It was shown previously that although systemic arterial pressure is increased by phenylephrine, pancreatic microcirculatory perfusion is decreased. Because inadequate tissue perfusion may be critical in the progression of edematous pancreatitis to parenchymal necrosis, it was hypothesized that vasoconstrictors might be harmful in pancreatitis. Therefore the effect of phenylephrine on cerulein-induced mild pancreatitis were studied. Sprague-Dawley rats (n = 54) were randomly allocated to 6 experimental groups and subjected to the following infusion regimens: (1) cerulein (cae) + phenylephrine (phe), (2) cae + saline (NS), (3) NS + phe, (4) cae + phenoxybenzamine (pbz) + phe, (5) NS + pbz + phe, and (6) NS. Initial and terminal hematocrit, serum amylase activity, and blood ionized calcium concentration were determined. The animals were killed 9 hours after starting the infusion. Macroscopic and histologic changes were scored by a 'blinded' pathologist. Phenylephrine increased the severity of cerulein-induced pancreatitis as manifested by statistically significant adverse changes in serum amylase, hematocrit, ionized calcium, peripancreatitic soap formation, and acinar cell vacuolization. These changes were antagonized by alpha-adrenergic receptor blockade with phenoxybenzamine. It is concluded that phenylephrine is deleterious in acute experimental pancreatitis, the first demonstration of such an effect by a pharmacologic vasoconstrictor, and suggested that microcirculatory changes may be important in the transition of mild to severe pancreatitis. Caution in the use of vasoconstrictor drugs in patients with acute pancreatitis is recommended.
Clinical effect of continuous gastric cooling for massive GI bleeding in uremia. Continuous gastric cooling (CGC) with dialysate was done in nine hemodiaysis patients with massive gastro-intestinal (GI) bleeding. Eight patients were treated by direct irrigation using a double-lumen naso-gastric (NG) tube without balloon. Four patients with bleeding from the duodenum (B-f-D) had complete hemostasis, and there was only one recurrence. However, two out of four patients with bleeding from the stomach (B-f-S) had complete hemostasis, but all four suffered recurrence. The NG tube had to be reinserted in three patients with B-f-S because of obstruction by clots. The direct irrigation method of CGC thus appears to be more effective for the treatment of B-f-D than B-f-S, so we investigated a three lumen, single-balloon catheter (3L-SBC) with which the bleeding site in the stomach can be cooled and pressed without removing coagula. CGC using the 3L-SBC was done in one patient with B-f-S, and complete hemostasis was obtained without recurrence.
Preliminary results of left heart bypass in pigs using a heparin-coated centrifugal pump. To assess the feasibility of left ventricular assist without systemic heparinization, we used a commercially available (Sarns 3M) centrifugal pump with tubing set and cannulas, all internally precoated for the purpose of this study with heparin, to bypass the left ventricle in 12 pigs for periods of either 1 or 3 hours. There was no significant activation of clotting and there was no sign of generalized embolization. However, on postmortem studies, 5 kidneys out of 22 examined showed signs of minimal thromboembolism. This experiment shows that artificial left ventricular assist, free of systemic heparinization but using heparin precoating, is feasible and safe, at least for a short period of time.
Detection of clinically suspected deep vein thrombosis using light reflection rheography. Venography is the current standard for the diagnosis of deep vein thrombosis (DVT). Noninvasive tests have differing sensitivity and specificity, are technically demanding, and may be subject to variability in interpretation. Light reflection rheography (LRR) is a noninvasive method utilizing light-emitting diodes and a sensor to measure light reflected from the skin surface. The intensity of reflected light establishes a graphic pattern that indirectly quantifies parameters of venous function by measuring changes in the microcirculation. Seventy-two patients who underwent contrast venography at our institution were also evaluated with LRR. Twenty-four patients were found to have DVT as demonstrated by venography. Of these, 23 also had DVT detected by LRR. No evidence of thrombus was seen in 45 patients studied by venography; in this group, 35 had normal venous emptying indicated by LRR. Using LRR, a sensitivity of 96% was achieved in the evaluation of clinically suspected DVT. This sensitivity is comparable with other noninvasive tests. In addition, LRR is easy to operate, portable, inexpensive, and not technically demanding. Further investigation is needed to confirm these data and further define the role of LRR in the evaluation of clinically suspected DVT.