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R Green

Publications and source records attributed to R Green.

At least 109 records · Page 6Linked to original sources
PubMed1999

Use of intervening unstained slides for immunohistochemical stains for high molecular weight cytokeratin on prostate needle biopsies.

Immunohistochemical stains (IHC) stains for high molecular weight cytokeratin (HMWCK) may show the presence or absence of basal cells in a small focus of atypical glands helping to establish a benign or malignant diagnosis respectively. From January 1994 to the present, we have generated intervening unstained slides on all prostate needle biopsies for potential IHC stains for HMWCK because lesions may not survive deeper sectioning into the block. Of 1105 prostate needle biopsy cases seen at Johns Hopkins from January 1994 to December 1996, IHC staining for HMWCK was initially done on 94 (8.5%). To see whether lesions would still have been present for evaluation if we did not have intervening slides, we repeated the IHC stains for HMWCK off the paraffin blocks in 74 cases for which material was available for study. Care was taken not to trim the blocks. In 52 cases, the original HMWCK helped to establish a diagnosis; in 31 of these cases the lesion was not present on repeat IHC stains from the block. Of these 31 cases, the original HMWCK from intervening unstained slides helped to establish cancer (n = 23) or a benign (n = 8) diagnosis. The use of intervening unstained slides was critical to establish a diagnosis in 31 (2.8%) of 1105 prostate needle biopsies and saved the cost of repeat biopsy ($68,200) and spared these patients from a second surgical procedure.

Humans↗
PubMed1999

Clinical and pathologic predictors of survival in patients with thymoma.

OBJECTIVE: To evaluate the Johns Hopkins Hospital experience with 136 thymomas over the past 40 years. This number of patients allowed quantitative estimation of the independent influence of common clinicopathologic risk factors using multivariate analysis. SUMMARY BACKGROUND DATA: Thymomas vary widely in terms of recurrence and influence on overall survival. Several series have indicated the importance of initial tumor invasion, as well as the extent of surgical resection, as predictors of recurrence and survival after thymoma resection. However, findings have been equivocal when other predictors of prognosis were examined. METHODS: The authors evaluated 136 patients seen at the Johns Hopkins Hospital between 1957 and 1997 with a pathologic diagnosis of thymoma. Demographic information, clinical staging data, surgical and adjuvant treatment details, and patient follow-up data were obtained from the patient record and from detailed patient or family interviews. Microscopic sections of all 136 patients were reviewed by two pathologists blinded to the clinical data. All data were analyzed by multivariate Cox regression analysis, which allowed the quantification of the independent predictive value of 12 putative clinicopathologic prognostic indicators. RESULTS: Completeness of follow-up was 99%, 99%, and 98% of eligible patients at 5, 10, and 15 years, respectively. Forty percent of the patients had associated myasthenia gravis and 27% had a secondary primary malignancy. Overall patient survival rates were 71%, 56%, 44%, 38%, and 33% at 5, 10, 15, 20, and 25 years, respectively. Overall, the thymoma-related mortality rate was 14%; the nonthymoma-related mortality rate was 26%. Incomplete resection, preoperative absence of myasthenia gravis, and advanced Lattes/Bernatz pathologic class were found to be independent predictors of poorer overall survival. CONCLUSIONS: These findings support a policy of aggressive, complete surgical resection of all thymomas when feasible. Thymoma behaves as a rather indolent tumor, with most deaths from causes unrelated to thymoma or its direct treatment. Clinicians should have an increased awareness of the possibility of second primary malignancies in patients with thymoma.

Adolescent↗
PubMed1999

Shortening of the long forehead.

A long forehead disrupts the harmony among the facial components and may contribute to the semblance of facial aging. Slight forehead length disharmony on a senescent face can be corrected by placing the incision at the hairline, elevating the eyebrows through subcutaneous or subgaleal dissection, and removing excess skin without posterior scalp immobilization. For moderate to major reduction of the forehead length, the scalp is elevated back to the occipital region through a pretrichial incision, and relaxation incisions are made at a right angle to the vector of advancement. The entire scalp is then repositioned anteriorly, advancing the hairline caudally and shortening the forehead. Retraction of the scalp or excessive elevation of the eyebrows is prevented by anchoring the galeal fascia to the cranial bone using a bone-tunneling technique in one to three rows. The number of fixation rows is commensurate to the amount of advancement and rigidity of the scalp. The more immobile the scalp preoperatively, the more relaxation incisions and fixation tunnels are necessary. Following caudal repositioning of the scalp, the non-hair-bearing skin is excised, and a meticulous repair is done. These procedures have been performed in 180 patients with a high degree of satisfaction. Temporary hair loss was experienced in one smoker who underwent the most advancement through posterior scalp elevation and continued to smoke postoperatively. Also, on three patients in the subcutaneous forehead rhytidectomy group, two of whom were smokers, delayed healing was observed in the temple area because of compromised circulation requiring secondary revision.

Forehead↗
PubMed1999

Saccharomyces cerevisiae mid2p is a potential cell wall stress sensor and upstream activator of the PKC1-MPK1 cell integrity pathway.

The MID2 gene of Saccharomyces cerevisiae encodes a protein with structural features indicative of a plasma membrane-associated cell wall sensor. MID2 was isolated as a multicopy activator of the Skn7p transcription factor. Deletion of MID2 causes resistance to calcofluor white, diminished production of stress-induced cell wall chitin under a variety of conditions, and changes in growth rate and viability in a number of different cell wall biosynthesis mutants. Overexpression of MID2 causes hyperaccumulation of chitin and increased sensitivity to calcofluor white. alpha-Factor hypersensitivity of mid2Delta mutants can be suppressed by overexpression of upstream elements of the cell integrity pathway, including PKC1, RHO1, WSC1, and WSC2. Mid2p and Wsc1p appear to have overlapping roles in maintaining cell integrity since mid2Delta wsc1Delta mutants are inviable on medium that does not contain osmotic support. A role for MID2 in the cell integrity pathway is further supported by the finding that MID2 is required for induction of Mpk1p tyrosine phosphorylation during exposure to alpha-factor, calcofluor white, or high temperature. Our data are consistent with a role for Mid2p in sensing cell wall stress and in activation of a response that includes both increased chitin synthesis and the Mpk1p mitogen-activated protein kinase cell integrity pathway. In addition, we have identified an open reading frame, MTL1, which encodes a protein with both structural and functional similarity to Mid2p.

Benzenesulfonates↗
PubMed1999

Braincutting for psychiatrists: the time is ripe.

In the past two decades, neuroscientific investigations such as postmortem and neuroimaging studies have revealed a variety of regional brain disturbances in major mental illnesses. These emerging findings are difficult to appreciate fully without a sufficient grasp of the neuroanatomy of the regions identified in these studies. The authors have developed, for psychiatrists-in-training, a braincutting exercise designed to highlight the neuroanatomical features of specific regions; namely, regions with behavioral affiliations relevant to contemporary hypotheses about the brain bases of major mental disorders. The focus of the braincutting is markedly different from the traditional braincuttings that have been available to trainees in neurology, neurosurgery, and neuropathology. This article describes the authors' approach to braincutting and the behavioral neuroanatomy seminar of which it is a part.

Brain↗
PubMed1999

A comparison of some clinical features of visual reinforcement audiometry and the distraction test.

The aim of this study was to compare aspects of visual reinforcement audiometry (VRA) and the distraction test (DT), the two most commonly used behavioural tests of hearing for young children. The number of assessments completed, time taken, parental opinion and levels of minimum responses were compared in a group of 20 infants (mean age 17.7 months; SD 4.7 months; range 12-25 months) who had been selected from those referred from a local second-tier community audiology service. Each infant was assessed with each test following set protocols and a balanced design on two occasions separated by one week. Parental opinion was determined by application of two questionnaires, one after each session. There was no difference in the number of minimum response levels (MRLs) measured by the two tests. However, if a VRA protocol using three MRLs was assumed then the assessment was completed successfully in a significantly greater number of subjects with VRA. VRA took, on average, two minutes less than the DT to measure six MRLs. Most of the subject sample had normal hearing as defined by both tests. However, where MRLs were >30 dB HL for at least one of the tests, the DT elicited responses at significantly higher levels than VRA, suggesting that in these subjects the DT under-estimated hearing sensitivity. Seventy per cent of parents selected VRA when asked to choose between the tests.

Attention↗
PubMed1999

Folate deficiency beyond megaloblastic anemia: hyperhomocysteinemia and other manifestations of dysfunctional folate status.

Folate plays a key role in nucleic acid synthesis. As a consequence, the most conspicuous complication of folate deficiency or of derangements of folate metabolism is megaloblastic macrocytic anemia caused by interdiction of normal proliferation of rapidly dividing bone marrow cells. Other rapidly dividing cells, including those in the gastrointestinal tract, may also be affected by the megaloblastic process. This may result in malabsorption. However, there is mounting evidence to indicate that there are other earlier manifestations of folate deficiency or of longstanding suboptimal folate nutrition. Chief among these manifestations of folate deficiency are an increased predisposition to occlusive vascular disease and thrombosis, which have been linked to increased levels of homocysteine found in folate deficiency and abnormal states of folate metabolism. In addition, folate deficiency, previously considered free of neurological consequences, is now known to be associated with disturbances of mood, and even spinal cord syndromes similar to those seen in vitamin B12 deficiency. Finally, there is both experimental and clinical evidence to suggest that folate deficiency may interfere with immunologic status and may be associated with an increased predisposition to neoplasia. Nutritional as well as genetic factors may contribute to these various nonhematological manifestations of folate insufficiency.

Anemia, Megaloblastic↗
PubMed1998

Alterations in acid-base balance and serum electrolyte concentrations in cattle: 632 cases (1984-1994).

OBJECTIVE: To determine typical alterations in acid-base balance and serum electrolyte concentrations in cattle grouped on the basis of age, breed type, hydration status, clinical signs, and underlying disease. DESIGN: Retrospective study. ANIMALS: 632 cattle. PROCEDURE: Information on blood pH, PVO2, PVCO2, HCO3-concentration, and base excess (BE) as well as serum or plasma sodium, potassium, chloride, and total carbon dioxide concentrations was obtained. Values for calves (ie, cattle < 1 month old) were compared with values for cattle > or = 1 month old. Within each age-group, values were compared for cattle grouped on the basis of breed type, previous treatment, and hydration status. Proportions of cattle with various disorders for which values were within, greater than, or less than reference ranges were determined. RESULTS: BE, pH, and HCO3- concentration were significantly higher and PVCO2 and sodium, potassium, and chloride concentrations were significantly lower among cattle > or = 1 month old than calves. Base excess and HCO3- concentration were significantly lower among dairy than beef calves. Sodium and potassium concentrations were significantly lower among dairy than beef cattle > or = 1 month old. A higher proportion of cattle that did not survive had a high anion gap than cattle that did survive. Sodium, potassium, and chloride concentrations were significantly lower among dehydrated cattle than cattle that were not dehydrated. CLINICAL IMPLICATIONS: Because certain alterations were consistently found in some groups of cattle, it may be possible to make reasonable predictions of alterations in acid-base balance and serum electrolyte concentrations when laboratory evaluations are not available.

Acid-Base Equilibrium↗
PubMed1998

Ribosome-catalyzed peptide-bond formation with an A-site substrate covalently linked to 23S ribosomal RNA.

In the ribosome, the aminoacyl-transfer RNA (tRNA) analog 4-thio-dT-p-C-p-puromycin crosslinks photochemically with G2553 of 23S ribosomal RNA (rRNA). This covalently linked substrate reacts with a peptidyl-tRNA analog to form a peptide bond in a peptidyl transferase-catalyzed reaction. This result places the conserved 2555 loop of 23S rRNA at the peptidyl transferase A site and suggests that peptide bond formation can occur uncoupled from movement of the A-site tRNA. Crosslink formation depends on occupancy of the P site by a tRNA carrying an intact CCA acceptor end, indicating that peptidyl-tRNA, directly or indirectly, helps to create the peptidyl transferase A site.

Anti-Bacterial Agents↗
PubMed1998

High homocysteine, low folate, and low vitamin B6 concentrations: prevalent risk factors for vascular disease in heart transplant recipients.

BACKGROUND: A high plasma homocysteine concentration is a risk factor for atherosclerosis and thrombosis, which are major causes of morbidity and mortality in heart transplant patients. High homocysteine concentrations may be caused by lower folate and vitamin B6 levels. We hypothesized that these patients might have high homocysteine concentrations and low levels of folate and vitamin B6, which could contribute to the development of vascular complications. METHODS: Total fasting plasma homocysteine was measured in 189 cardiac transplant recipients and in healthy controls, as were concentrations of folate, vitamin B12, vitamin B6, and creatinine. RESULTS: Homocysteine concentrations were higher in recipients than controls (19.1+/-13.0 vs. 11.0+/-3.0 micromol/L, P<0.01), and hyperhomocysteinemia (>90th percentile for controls, 14.6 micromol/L) was seen in 68% of recipients (P<0.01). Folate and vitamin B6 concentrations were lower (5.9+/-4.2 vs. 7.9+/-4.2 pmol/L and 40+/-25 vs. 84+/-77 nmol/L, respectively; P<0.01 for both). Folate and vitamin B6 deficiencies were seen in 10.8% and 17.91% of recipients, respectively (P<0.01). Hyperhomocysteinemia was more frequent in patients with vascular complications after transplantation than in those without (79.2% vs. 63.8%, P<0.05). CONCLUSIONS: Elevated plasma homocysteine and deficiencies of folate and vitamin B6 are common in transplant recipients. A high homocysteine concentration was more common in patients with vascular complications. Prospective studies are now required to evaluate the role of these abnormalities as risk factors for the atherothrombotic complications of transplantation.

Arteriosclerosis↗
PubMed1998

High cerebrospinal fluid tau and low amyloid beta42 levels in the clinical diagnosis of Alzheimer disease and relation to apolipoprotein E genotype.

OBJECTIVE: To evaluate cerebrospinal fluid (CSF) levels of amyloid beta protein ending at amino acid 42 (Abeta42) and tau as markers for Alzheimer disease (AD) and to determine whether clinical variables influence these levels. DESIGN: Cohort study. SETTING: Six academic research centers with expertise in dementia. SUBJECTS: Eighty-two patients with probable AD, including 24 with very mild dementia (Mini-Mental State Examination score >23/30) (AD group); 60 cognitively normal elderly control subjects (NC group); and 74 subjects with neurological disorders, including dementia (ND group). MAIN OUTCOME MEASURES: Levels of Abeta42 and tau were compared among AD, NC, and ND groups. Relationships of age, sex, Mini-Mental State Examination score, and apolipoprotein E (Apo E) genotype with these levels were examined using multiple linear regression. Classification tree models were developed to optimize distinguishing AD from NC groups. RESULTS: Levels of Abeta42 were significantly lower, and levels of tau were significantly higher, in the AD group than in the NC or ND group. In the AD group, Abeta42 level was inversely associated with Apo E epsilon4 allele dose and weakly related to Mini-Mental State Examination score; tau level was associated with male sex and 1 Apo E epsilon4 allele. Classification tree analysis, comparing the AD and NC subjects, was 90% sensitive and 80% specific. With specificity set at greater than 90%, the tree was 77% sensitive for AD. This tree classified 26 of 74 members of the ND group as having AD. They had diagnoses difficult to distinguish from AD clinically and a high Apo E epsilon4 allele frequency. Markers in CSF were used to correctly classify 12 of 13 patients who later underwent autopsy, including 1 with AD not diagnosed clinically. CONCLUSIONS: Levels of CSF Abeta42 decrease and levels of CSF tau increase in AD. Apolipoprotein E epsilon4 had a dose-dependent relationship with CSF levels of Abeta42, but not tau. Other covariates influenced CSF markers minimally. Combined analysis of CSF Abeta42 and tau levels discriminated patients with AD, including patients with mild dementia, from the NC group, supporting use of these proteins to identify AD and to distinguish early AD from aging. In subjects in the ND group with an AD CSF profile, autopsy follow-up will be required to decide whether CSF results are false positive, or whether AD is a primary or concomitant cause of dementia.

Adult↗
PubMed1998

Estrogen and memory in a transsexual population.

The association between administered estrogen and performance on verbal memory and other cognitive tasks was examined. Male-to-female transsexuals undergoing estrogen treatment for sex reassignment (n = 29) scored higher on Paired Associate Learning (PAL) compared to a similar transsexual control group, awaiting estrogen treatment (n = 30) (P < 0.05). No differences between groups receiving and not receiving estrogen were detected on a control memory task (Digit Span) or on other cognitive tasks including Mental Rotations and Controlled Associations. There were no group differences in age. Group differences in mood or in general intellectual ability also did not explain the findings. Results suggest a specific influence of estrogen in men on verbal memory tasks, similar to that seen in prior studies of women. They are discussed in terms of differential processing demands of the two memory tasks and possible differences between estrogenic influences on Mental Rotations and Controlled Associations in men versus women.

Adult↗
PubMed1998

Emergency department observation unit: can it be funded through reduced inpatient admission?

STUDY OBJECTIVE: We sought to test the assumption that an emergency department observation unit can be funded through the reallocation of resources made available through the unit's impact in reducing inpatient admissions and facilitating bed closures. METHODS: We conducted our study in a tertiary care center ED with 46,000 visits annually. For a 3-month period, all patients admitted to the hospital through the ED were screened by an emergency physician for suitability for admission to an observation unit. Any patient in the hospital for 3 days or less who did not undergo surgery or other inpatient procedure, and who was admitted through the ED, was considered a candidate for the observation unit. RESULTS: Of 1,840 admissions, 147 patients met the admission criteria. Only 48 (32.2%) could have been treated in an observation unit, and these patients were not admitted to any single unit in high frequency. The potential savings from inpatient bed closures would only have amounted to 1.68 full-time equivalents-not enough to staff a 4-bed observation unit, which would require 5 full-time equivalents. CONCLUSION: Because of the diffuse and inconsistent effect such a unit had on inpatient bed use, funding for an ED observation unit at our institution could not be justified on the basis of the closure of inpatient beds and transfer of resources.

Adolescent↗
PubMed1998

Endovascular treatment of renal artery thrombosis caused by umbilical artery catheterization.

Renal arterial thrombosis, usually in association with aortic thrombosis, has been reported as a result of prolonged neonatal umbilical artery catheterization. A case of renal artery thrombosis attributable to umbilical artery catheterization, resulting in malignant renovascular hypertension, in a 15-day-old neonate, treated by catheter-directed thrombolysis through the involuting umbilical artery, was studied. Resolution of systemic hypertension and partial return of right renal function followed rapid thrombus dissolution.

Catheterization↗
PubMed1998

The implementation of an integrated on-line health education system at RMIT.

The Faculty of Biomedical and Health Sciences at RMIT has been developing an on-line health education system using a systems thinking approach, to create a learning environment whose basis is supported by Information Technology (IT). The centre-piece of this system is the Faculty Learning Centre, which has been created, both in space and layout, to promote collaborative learning between the students, so that the educator is physically assimilated with the student body. This facility is supplemented by the Faculty WWW server, which has been the main vehicle for course material dissemination to students. To ensure an effective on-line teaching environment, the position of an on-line facilitator has been created, whose responsibilities include both the continual evaluation of the system and the implementation of appropriate system changes. Aspects have included the production of a staff development training program and extensive user documentation. This paper discusses the systems thinking approach used to implement this integrated on-line system, and the establishment of explicit educational rationales in the use of IT to support learning strategies. Some examples of the on-line educational programs are also presented.

Australia↗