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Biomedical subjects

F Yu

Publications and source records attributed to F Yu.

At least 91 records · Page 5Linked to original sources
PubMed1998

Effect of long-term gastric acid suppressive therapy on serum vitamin B12 levels in patients with Zollinger-Ellison syndrome.

BACKGROUND AND AIMS: Long-term treatment with H(+)-K(+)-adenotriphosphatase (ATPase) inhibitors, such as omeprazole or lansoprazole, for severe gastroesophageal reflux disease is now widely used. Whether such treatment will result in vitamin B12 deficiency is controversial. We studied whether long-term treatment with omeprazole alters serum vitamin B12 levels in patients with Zollinger-Ellison syndrome. METHODS: In 131 consecutive patients treated with either omeprazole (n = 111) or histamine H2-receptor antagonists (n = 20), serum vitamin B12 and folate levels and complete blood counts were determined after acid secretion had been controlled for at least 6 months. These studies were repeated yearly. Serum vitamin B12 and folate levels were correlated with the type of antisecretory drug and the extent of inhibition of acid secretion. RESULTS: The mean duration of omeprazole treatment was 4.5 years, and for H2-receptor antagonists 10 years. Vitamin B12 levels, but not serum folate levels or any hematological parameter, were significantly (P = 0.03) lower in patients treated with omeprazole, especially those with omeprazole-induced sustained hyposecretion (P = 0.0014) or complete achlorhydria (P < 0.0001). In 68 patients with two determinations at least 5 years apart, vitamin B12 levels decreased significantly (30%; P = 0.001) only in patients rendered achlorhydric. The duration of omeprazole treatment was inversely correlated with vitamin B12 levels (P = 0.013), but not folate levels. Eight patients (6%) developed subnormal B12 levels during follow-up. CONCLUSIONS: Long-term omeprazole treatment leads to significant decreases in serum vitamin B12 but not folate levels. These results suggest patients with Zollinger-Ellison syndrome treated with H(+)-K(+)-ATPase inhibitors should have serum vitamin B12 levels monitored. Furthermore, these results raise the possibility that other patients treated chronically with H(+)-K(+)-ATPase inhibitors may develop B12 deficiency.

Achlorhydria↗
PubMed1998

Functional status and well-being in patients with glaucoma as measured by the Medical Outcomes Study Short Form-36 questionnaire.

PURPOSE: This study aimed to determine whether patients with glaucoma have different functional status and well-being than patients without glaucoma. DESIGN: Prospective case-control study. PARTICIPANTS: The study population was recruited from 2 university-based glaucoma clinical practices and a university-based general ophthalmology clinic and consisted of 121 patients with open-angle glaucoma, 42 with diagnosis of glaucoma suspect, and 135 with no chronic ocular conditions except cataract. INTERVENTION: Administration of Medical Outcomes Study 36-item short-form survey (SF-36) was performed. Demographic information, medical history, and responses to the SF-36 questionnaire were elicited by an interviewer. Medical record review was performed to obtain clinical examination data and to substantiate the medical and demographic data obtained by the interviewer. MAIN OUTCOME MEASURES: The SF-36 scores by diagnostic group, demographic characteristics, and medical history were examined. Secondary outcome measures were SF-36 scores in patients with glaucoma by visual field impairment and glaucoma medication use. RESULTS: Patients with glaucoma consistently had lower scores, control subjects had higher scores, and glaucoma suspects had scores intermediate between the two groups. After adjusting for the possible influence of all the other covariate factors, glaucoma was found to be a strong predictor of lower SF-36 scores. CONCLUSION: Patients with glaucoma have lower scores, indicating less-functional status, than patients without glaucoma as tested by the SF-36 survey questionnaire.

Adult↗
PubMed1998

Factors associated with elevated rates of adverse outcomes after cyclodestructive procedures versus drainage device procedures.

OBJECTIVE: To identify factors associated with an increased risk of adverse outcomes after cyclodestructive or drainage device procedures. DESIGN: Retrospective, cohort analysis. PARTICIPANTS: A total of 5570 Medicare patients who were older than 65 years of age and who underwent cyclodestructive or drainage device procedures in 1994 participated. INTERVENTION: The authors identified cyclodestructive and drainage device procedures from claims to the Health Care Finance Administration (HCFA) by International Classification of Diseases (ICD-9) procedure codes, Current Procedural Terminology procedure codes, and HCFA Common Procedural Classification System codes. The authors analyzed adverse outcome rates using hierarchical logistic regression. Race, age group, gender, length of observed follow-up, state in which surgery took place, ocular procedures performed before and at the same time as the index surgery, and ocular diagnosis were included as covariates in the model. MAIN OUTCOME MEASURES: The authors defined an adverse outcome as the occurrence after the index surgery of at least one of the following: repeat cyclodestructive or drainage device procedure, retinal hole-tear repair, retinal detachment repair, surgery for endophthalmitis, vitrectomy, enucleation, evisceration, surgery for ocular hypotony, and/or extrusion or revision of drainage device. Adverse outcomes were also defined without the inclusion of repeat cyclodestructive or drainage device procedures. RESULTS: When repeat cyclodestructive or drainage device procedures were not included in the definition of an adverse outcome, eyes with a drainage device procedure were 3.8 times more likely to have an adverse outcome than eyes with a cyclodestructive procedure (odds ratio [OR], 3.8; 95% confidence interval [CI], 3.07, 4.67). Subjects with concurrent corneal transplant had increased odds of an adverse outcome compared to subjects without a concurrent corneal transplant (OR, 2.00; 95% CI, 1.27, 3.15). When the definition of an adverse outcome included repeat cyclodestructive or drainage device procedures, the odds of an adverse outcome were similar for both cyclodestructive and drainage device procedures (OR, 0.94; 95% CI, 0.79, 1.13). CONCLUSIONS: Cyclodestructive procedures need to be repeated more frequently than drainage device procedures. However, if the patient has a drainage device procedure, then that patient is more likely to have other types of adverse ophthalmic events than if he or she had a cyclodestructive procedure. Because the average follow-up of subjects in this study is 5 months (range, 0-12 months), outcomes that might take longer to manifest themselves would be excluded from this study.

Aged↗
PubMed1998

Factors associated with elevated complication rates after partial-thickness or full-thickness glaucoma surgical procedures in the United States during 1994.

OBJECTIVE: The purpose of the study was to identify factors associated with an increased risk of complications after partial-thickness or full-thickness glaucoma surgery. DESIGN: A retrospective, cohort analysis. PARTICIPANTS: A total of 24,206 Medicare patients who were older than 65 years of age and who were enrolled in Medicare in 1994 underwent partial-thickness or full-thickness glaucoma surgical procedures in 1994. INTERVENTION: The authors obtained data on all glaucoma surgery claims to the Health Care Finance Administration in 1994 and analyzed complication rates using hierarchical logistic regression, separately smoothing four sets of regression coefficients (state-level effects, systemic and ocular diagnoses, prior ocular surgeries, and concomitant ocular surgeries). MAIN OUTCOME MEASURE: Patients were classified as having complications if their records showed at least one of the following occurrences after surgery: retinal detachment repair, endophthalmitis, scleral fistula revision-repair, or cyclodestruction. RESULTS: The risk of complications was greater for full-thickness procedures than for partial-thickness procedures (odds ratio [OR] = 1.51; 95% confidence interval [CI] = 1.07, 2.12). Compared to glaucoma surgeries performed without an additional intraocular procedure, glaucoma surgery with prior phacoemulsification (OR = 0.51; 95% CI = 0.35, 0.74) was associated with lower complication rates, as was glaucoma surgery with prior argon laser trabeculoplasty (OR = 0.62; 95% CI = 0.44, 0.88). A concomitant vitrectomy (OR = 1.86, 95% CI = 1.35, 2.56) was associated with greater odds of a complication. The mean follow-up of subjects was 184 days (standard deviation, +/- 107), whereas the mean time to a complication was 49 days (standard deviation, +/- 63). CONCLUSION: The risk of an early postoperative complication after full-thickness procedures appears to be greater than that after partial-thickness procedures. Concomitant intraocular procedures performed in conjunction with glaucoma surgery, such as a vitrectomy, can substantially increase the risk of retinal detachment repair, endophthalmitis, scleral fistula revision-repair, and/or cyclodestruction.

Aged↗
PubMed1998

Effects of age and gender on shortening velocity and myosin isoforms in single rat muscle fibres.

The maximum velocity of unloaded shortening (V0) and the myosin heavy chain (MyHC) and light chain (MyLC) isoform composition were determined in single fibres from soleus and extensor digitorum longus (EDL) muscles of male and female rate 3-6 and 22-24 months old. In the soleus muscle, the beta/slow (type I MyHC) isoform predominated in both young and old animals, irrespective of gender. In the EDL, fibres expressing type IIX MyHC or a combination of IIX and IIB (IIXB) MyHC isoforms were predominant in old rats, while type IIB MyHC fibres predominated in young individuals of both genders. The V0 of soleus fibres expressing the type I MyHC isoform decreased (P < 0.001) by 40% with age in spite of an unchanged MyLC composition. In the EDL, the V0 of fibres expressing IIX, IIXB and IIB MyHC isoforms did not changes with age or differ between males and females. In conclusion, similar age-related changes in V0 and MyHC composition were observed in single muscle cells from both male and female rats. The present results demonstrate that the relationship between V0 and MyHC isoform composition at the single fibre level is similar in male and female rats, and that similar qualitative changes take place during ageing in both genders.

Aging↗
PubMed1998

Iron absorption in patients with Zollinger-Ellison syndrome treated with long-term gastric acid antisecretory therapy.

BACKGROUND: Gastric acid secretion is important for absorption of dietary non-haem iron, and iron deficiency is common in gastric hyposecretory states such as after gastric resection. It is not known if prolonged, continuous treatment with potent acid suppressants such as omeprazole will lead to iron deficiency or lower body iron stores. AIM: To assess iron stores and the occurrence of iron deficiency anaemia in patients with Zollinger-Ellison syndrome (ZES) treated long-term with gastric antisecretory drugs. METHODS: One hundred and nine patients with ZES but without previous gastric resections were studied. All patients underwent assessment of acid control on antisecretory agents, determination of tumour extent, evaluation of haematological parameters (Hct, haemoglobin, WBC, MCV, MCHC), and determination of serum iron parameters (iron, ferritin, transferrin, iron/ transferrin ratio). Acid control values for the last 4 years were reviewed, the presence or absence of acid hyposecretion determined using three different criteria and this result correlated with haematological and iron parameters. RESULTS: Eighty-nine patients were taking omeprazole, nine patients were taking histamine H2-antagonists and 11 patients were taking no drugs following curative resection. The mean duration of omeprazole treatment was 5.7 years (range 0.7-12.5 years) and total duration of any treatment was 10.1 years (range 0.7-21 years). Acid hyposecretion was present by at least one criterion in 45% of patients. There were no significant differences between patients with or without acid hyposecretion, taking or not taking omeprazole, having different durations of omeprazole treatment or different durations of total time receiving any antisecretory treatment, for any serum iron parameter, haematological parameter, or for the frequency of iron deficiency. Males and females did not differ in percentage with low ferritin levels or percentage with iron deficiency. CONCLUSIONS: Continuous treatment with omeprazole for 6 years or continuous treatment with any gastric antisecretory drug for 10 years does not cause decreased body iron stores or iron deficiency. These results suggest that, in contrast to recent results which show yearly monitoring of vitamin B12 in such patients is needed, such monitoring for iron parameters is not necessary.

Adolescent↗
PubMed1998

Annual predictions of adverse outcomes after glaucoma surgery in the United States.

PURPOSE: To predict the number of adverse outcomes or additional ocular surgeries after glaucoma surgery in each year from 1990 to 1994 with ordinary and hierarchical logistic regression models developed with 1989 Medicare data. METHODS: We obtained data on all intraocular and laser glaucoma surgery claims (for example, laser trabeculoplasty, full-thickness and partial-thickness procedures, and cycloablation) to the Health Care Finance Administration (HCFA) in 1989 and developed an ordinary (non-hierarchical) logistic regression model and two hierarchical logistic regression models. The two hierarchical models smoothed state-level effects to different degrees in an effort to improve the precision of model predictions. RESULTS: The hierarchical logistic regression models predicted the number of adverse outcomes or additional ocular surgeries, including repeat glaucoma surgery, from 1990 to 1994 significantly better than the ordinary model. None of the models predicted the downward trend in adverse outcomes in 1990 and 1992, although all three models were able to predict the increase in adverse outcomes in 1991 and the downward trend in adverse outcomes in 1993 and 1994. CONCLUSION: Although systematic changes over time in physician practice or billing patterns affected the ability of both ordinary and hierarchical regression models to predict the number of adverse outcomes in 1990 and 1992, hierarchical logistic regression provides a useful framework for analyzing adverse event rates when the model contains many covariates with imprecisely estimated coefficients. The greater accuracy of predicted adverse event rates from ophthalmic surgeries obtained with hierarchical logistic regression will be useful for future planning and budgeting purposes.

Aged↗
PubMed1998

Bone metastases in patients with gastrinomas: a prospective study of bone scanning, somatostatin receptor scanning, and magnetic resonance image in their detection, frequency, location, and effect of their detection on management.

PURPOSE: To determine whether bone scan, magnetic resonance imaging (MRI), or somatostatin receptor scintigraphy (SRS) is best for identifying bone metastases in patients with gastrinomas, as well as their frequency and location, whether their detection affects management, and what patient subgroups should be examined. MATERIALS AND METHODS: One hundred fifteen patients with gastrinoma were prospectively studied. Patients were examined yearly and those with liver metastases were reexamined every 3 months. Based on clinical history, histology, growth pattern, and development of new bone lesions, possible bone metastases were classified as to whether they were or were not bone metastases. Imaging results were correlated at different times in the disease course and with disease extent. RESULTS: Bone scan was positive in 52 patients, MRI in seven, and SRS in six. Eight patients (7%) were determined to have bone metastases and MRI was correctly positive in seven, SRS in six, and bone scan in five. SRS or MRI was positive in all patients with bone metastases. Bone scan had significantly lower specificity and sensitivity, and a higher rate (P < .02) of false-negative results than MRI or SRS. Bone metastases occurred in 31% of patients with liver metastases and 0% with only lymph node metastases. The initial bone metastases were in the spine or sacrum (75%) followed in descending order by the pelvis or sacroiliac joints (38%), scapula or shoulder, and ribs. In all cases, detection of bone metastases changed the management. CONCLUSION: SRS and MRI, because of high sensitivity and specificity, are recommended over bone scanning to screen for bone metastases in patients with gastrinomas. However, because bone metastases can occur initially outside the axial skeleton, SRS is the recommended initial localization method of choice. Bone metastases occur in 7% of all patients and 31% of patients with liver metastases, only occur in patients with liver metastases, are usually in the axial skeleton initially, and their detection changes management in all cases. Patients with pancreatic endocrine tumors with liver metastases should undergo SRS every 6 months to 1 year to detect bone metastases.

Adolescent↗
PubMed1998

[Clinical analysis of early complications in 132 low body weight infants performed open-heart surgery].

A clinical analysis of early complications in 132 low body weight infants undergoing open-heart surgery is reported. There were a higher risk of early complication associated with severe illness and/or experienced a longer duration time of cardiopulmonary bypass and endotracheal tube. The total complication rate was 42.4% and the major three complications were low cardiac output, acute respiratory distress syndrome and problems from endotracheal tube (occlusion and/or in proper position of tube). The author emphasized the importance of management of endotracheal tube after operation.

Body Weight↗
PubMed1998

[Analysis and toxicological evaluation of hazardous gases in sealed cabin].

82 volatile organic compounds (VOCs) of eight organic sorts and 3 target inorganic compounds in a sealed cabin that simulating the flying spaceship were identified and quantified for 5 d, the law of hazardous gas concentration variation was discussed, and the atmosphere toxicology was evaluated preliminarily. It provides a basis for detecting gas compounds and evaluating the atmosphere toxicology in the spaceship.

Air Pollutants↗
PubMed1998

[A robust method for automated retinal vascular images mosaic based on phase correlation method and mathematical morphology].

Precise mosaic techniques are essential for quantitative evaluation of retinal images to make early detection of fundus anomalies feasible. Opening of a gray-scale image by a gray-scale structuring element(SE) can generate a background image. Image mosaic was achieved by subtraction this background image from the original image and then applying a phase correlation method to find translation difference. Because of the accuracy characteristics of the phase correlation method and the speed of the FFT hardware, this new algorithm can work very fast and accurately, compared to conventional techniques. The method was also characterized by an outstanding robustness against correlated noise and disturbances, such as those encountered with nonuniform illumination. The results confirm the robustness of the chosen approach.

Algorithms↗
PubMed1997

Somatic mutations of the MEN1 tumor suppressor gene in sporadic gastrinomas and insulinomas.

Gastrinomas and insulinomas are frequent in multiple endocrine neoplasia type 1 (MEN1). The MEN1 tumor suppressor gene was recently identified. To elucidate the etiological role of the MEN1 gene in sporadic enteropancreatic endocrine tumorigenesis, we analyzed tumors (28 gastrinomas and 12 insulinomas) from 40 patients for MEN1 gene mutations and allelic deletions. One copy of the MEN1 gene was found to be deleted in 25 of 27 (93%) sporadic gastrinomas and in 6 of 12 (50%) sporadic insulinomas. MEN1 gene mutations were identified in 9 of 27 (33%) sporadic gastrinomas and 2 of 12 (17%) insulinomas and were not seen in corresponding germ-line DNA sequence. A specific MEN1 mutation was detected in one gastrinoma and in the corresponding germ-line DNA of a patient who had no family history of MEN1. Somatic MEN1 gene mutations and deletions play a critical role in the tumorigenesis of sporadic gastrinomas and may also contribute to the development of a subgroup of insulinomas.

Adolescent↗
PubMed1997

Protein kinase C is required for induction of 2',5'-oligoadenylate synthetases.

Induction of the p40/46 and p69/71 isoforms of the 2',5'-oligoadenylate (2-5A) synthetase by interferon-alpha (IFN-alpha) is variable among six different Burkitt lymphoma cell lines with Ramos cells expressing among the highest levels of these enzymes. Inhibitors of protein kinase C (PKC) block induction of mRNAs encoding both isoforms; however, induction of the p69/71 isoform is more sensitive to these inhibitors. Down-regulation of PKC by prolonged treatment with 12-O-tetradecanoylphorbol-13-acetate (TPA) also blocks induction of 2-5A synthetase mRNAs and decreases both constitutive and IFN-alpha-induced enzymatic activity. Cotreatment of cells with TPA and IFN-alpha increases induction of 2-5A synthetase mRNAs above that seen in cells treated with IFN-alpha alone. IFN-alpha does not directly activate PKC-alpha or PKC-delta, the two most abundant PKC isoforms present in Ramos cells, suggesting that PKC activation by another signaling pathway is necessary for maximal induction of 2-5A synthetases by IFN-alpha.

2',5'-Oligoadenylate Synthetase↗
PubMed1997

The partial tandem duplication of ALL1 in acute myeloid leukemia with normal cytogenetics or trisomy 11 is restricted to one chromosome.

The molecular defects responsible for tumorigenesis in adult de novo acute myeloid leukemia (AML) with a normal karyotype or an additional copy of one chromosome (i.e., trisomy) remain largely unknown. We recently discovered that approximately 90% of adult patients with de novo AML and trisomy 11 (+11) as a sole abnormality and 11% of adult patients with de novo AML and normal cytogenetics carry a molecular rearrangement of the ALL1 (MLL, HRX, or HTRX) gene. The rearranged ALL1 gene has been shown to result from the direct tandem duplication of a portion of ALL1 itself. To better understand the underlying mechanisms of leukemogenesis, we asked whether in cytogenetically normal cases one or both chromosomes carry the mutated allele and whether in trisomic cases the mutation is present in one, two, or three chromosomes. Herein we show that in cytogenetically normal cases of AML and in cases with +11 as a sole cytogenetic abnormality, only one chromosome contains the mutated ALL1 allele. Thus a single mutated ALL1 allele with the partial tandem duplication is sufficient for ALL1-associated leukemogenesis, irrespective of the number of normal genes present. The frequently occurring specific association of +11 and ALL1 gene mutation in the leukemic clone remains unexplained.

Adult↗
PubMed1997

Gender-related differences in the regulatory influence of thyroid hormone on the expression of myosin isoforms in young and old rats.

The effects of 4 weeks of thyroid hormone (3.5.3'-triiodothyronine. T3) treatment on the expression of myosin heavy chain (MyHC) isoforms were examined in young (3-6 months; and old (20-24 months) female rats, and compared with those in age-matched male rats (Larsson et al. 1995). In control rats ageing was associated with a type IIA to I MyHC isoform switching in the slow-twitch soleus and a type IIB to IIX MyHC isoform switching in the fast-twitch extensor digitorum longus muscle (EDL). Gender- and muscle-specific differences were observed in the regulation of MyHC isoforms by T3. In the soleus, dramatic downregulation of the type I and upregulation of the type IIA MyHC isoform were observed in both females and males, but upregulation of the IIX MyHC isoform was observed only in male rats. In EDL, T3 treatment had no significant influence on the MyHC isoform composition in the males irrespective of the age of the animal. In the females, on the other hand, T3 treatment resulted in a significant MyHC transformation from IIA to IIB, probably via IIX myosin, in spite of the fact that type IIA mRNA has been reported to be downregulated in both females and males. It is concluded that the regulation of MyHC isoforms by thyroid hormone differs between females and males, presumably as a result of a gender-related difference in the translational or post-translational regulation of MyHC synthesis.

Age Factors↗
PubMed1997

t(8;20)(q22;p13): a novel variant translocation of t(8;21) in acute myeloblastic leukaemia.

A novel variant translocation t(8;20)(q22;p13) detected by karyotype analysis of bone marrow cells using R- and G-banding techniques, is reported in a case of M2-acute myeloid leukaemia (AML). The leukaemic cells were indistinguishable morphologically from that of M2-AML with t(8;21)translocation. RT-PCR revealed no AML1/ETO fusion transcript, but the wild-type ETO-3' was expressed in the bone marrow cells suggesting that t(8;20) is a true simple variant translocation of t(8;21), and that a fusion gene consisting of ETO and an unidentified gene located in band 20p13 may exist in our case. Further study is required to clarify the entity of the assumed fusion gene.

Aged↗