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Biomedical subjects

S M Ehrlich

Publications and source records attributed to S M Ehrlich.

At least 19 recordsLinked to original sources
PubMed2001

Evidence that APC regulates survivin expression: a possible mechanism contributing to the stem cell origin of colon cancer.

Because colorectal cancers (CRCs) frequently display APC mutation, inhibition of apoptosis, and increased expression of the antiapoptotic protein survivin, we hypothesized that APC mutation inhibits apoptosis by allowing constitutive survivin expression. Using HT-29 CRC cell lines having inducible wild-type APC (wt-APC) or transfected dominant-negative TCF-4, we show that wt-APC down-regulates survivin expression via APC/beta-catenin/TCF-4 signaling. Using normal colonic epithelium, we found survivin by immunostaining/reverse transcription-PCR to be preferentially expressed in the lower crypt (which inversely correlates with wt-APC's expression pattern). Thus, wt-APC, by progressively decreasing survivin and increasing apoptosis from crypt bottom to top, may limit the population size of stem cells and other proliferative cells in the lower crypt; mutant APC may allow expansion of these populations, thereby initiating tumorigenesis.

Adenomatous Polyposis Coli Protein↗
PubMed1998

Depth information and perceived self-motion during simulated gaze rotations.

When presented with random-dot displays with little depth information, observers cannot determine their direction of self-motion accurately in the presence of rotational flow without appropriate extra-retinal information (Royden CS et al. Vis Res 1994;34:3197-214.). On theoretical grounds, one might expect improved performance when depth information is added to the display (van den Berg AV and Brenner E. Nature 1994;371:700-2). We examined this possibility by having observers indicate perceived self-motion paths when the amount of depth information was varied. When stereoscopic cues and a variety of monocular depth cues were added, observers still misperceived the depicted self-motion when the rotational flow in the display was not accompanied by an appropriate extra-retinal, eye-velocity signal. Specifically, they perceived curved self-motion paths with the curvature in the direction of the simulated eye rotation. The distance to the response marker was crucial to the objective measurement of this misperception. When the marker distance was small, the observers' settings were reasonably accurate despite the misperception of the depicted self-motion. When the marker distance was large, the settings exhibited the errors reported previously by Royden CS et al. Vis Res 1994;34-3197-3214. The path judgement errors observers make during simulated gaze rotations appear to be the result of misattributing path-independent rotation to self-motion along a circular path with path-dependent rotation. An analysis of the information an observer could use to avoid such errors reveals that the addition of depth information is of little use.

Cues↗
PubMed1996

Estimating heading during real and simulated eye movements.

The ability to judge heading during tracking eye movements has recently been examined by several investigators. To assess the use of retinal-image and extra-retinal information in this task, the previous work has compared heading judgments with executed as opposed to simulated eye movements. For eye movement velocities greater than 1 deg/sec, observers seem to require the eye-velocity information provided by extra-retinal signals that accompany tracking eye movements. When those signals are not provided, such as with simulated eye movements, observers perceive their self-motion as curvilinear translation rather than the linear translation plus eye rotation being presented. The interpretation of the previous results is complicated, however, by the fact that the simulated eye movement condition may have created a conflict between two possible estimates of the heading: one based on extra-retinal solutions and the other based on retina-image solutions. In four experiments, we minimized this potential conflict by having observers judge heading in the presence of rotations consisting of mixtures of executed and simulated eye movements. The results showed that the heading is estimated more accurately when rotational flow is created by executed eye movements alone. In addition, the magnitude of errors in heading estimates is essentially proportional to the amount of rotational flow created by a simulated eye rotation (independent of the total magnitude of the rotational flow). The fact that error magnitude is proportional to the amount of simulated rotation suggests that the visual system attributes rotational flow unaccompanied by an eye movement to a displacement of the direction of translation in the direction of the simulated eye rotation.

Cues↗
PubMed1996

Is constipation a disorder of defecation or impaired motility?: distinction based on defecography and colonic transit studies.

OBJECTIVE: The purpose of this study was to determine whether constipation is a disorder of defecation or of impaired motility by using defecography and transit studies. MATERIALS AND METHODS: Thirty-five patients (34 women, one man) with severe constipation underwent defecography and colonic transit studies in a 2-month period. Transit studies included the use of orally administered radiopaque markers and plain abdominal radiographs obtained up to 4 days later. Fluoroscopically guided defecography was performed with barium paste introduced into the rectum. RESULTS: Normal colonic transit time was observed in seven (20%) of the 35 patients. Abnormal findings included colonic inertia in six (17%) patients, hindgut dysfunction in 10 (29%) patients, and outlet obstruction in 12 (34%) patients. Rectocele, enterocele, descending perineum syndrome, and dyskinetic puborectalis were found equally in both groups of patients. Rectal prolapse was more commonly found in patients with hindgut dysfunction and outlet obstruction (p < .05). CONCLUSION: Surgical or medical management of severely constipated patients relies on objectively identifying the underlying pathophysiology. Our findings suggest that constipation is often a disorder of defecation rather than an impairment of colonic motility.

Adolescent↗
PubMed1995

Bilateral breast carcinoma: mammographic and histologic correlation.

PURPOSE: To determine the mammographic, histologic, and clinical features of bilateral breast cancer. MATERIALS AND METHODS: Pre-biopsy mammograms of 67 patients with bilateral carcinoma were reviewed. Lesions were synchronous in 35 patients and metachronous in 32. Mammographic appearance, lesion size and location, and bilateral similarities were evaluated. Axillary nodal status was noted. These characteristics were compared with those of unilateral cancers. RESULTS: Of 58 mammographically evident lesion pairs, 31 involved the same quadrant. Of the total 67 lesion pairs, 24 pairs were similar in appearance, and 15 had both mirror image location and a similar appearance. Of 17 lesion pairs considered to represent a single primary carcinoma with metastases to the contralateral breast, eight had a similar mirror image appearance and five had mirror image location and a similar mirror image appearance. The second cancer of metachronous pairs was smaller, with less frequent axillary nodal involvement. CONCLUSION: The appearance of bilateral breast cancer does not differ from that of unilateral carcinoma. Bilateral breast carcinomas frequently demonstrate a similar mammographic appearance and mirror image location.

Adult↗
PubMed1995

Trends in use of barium enema examination, colonoscopy, and sigmoidoscopy: is use commensurate with risk of disease?

PURPOSE: To assess replacement of barium enema examination with colonoscopy in relation to age- and sex-related risk factors, place of service, physician specialty, and cost. MATERIALS AND METHODS: Between 1985 and 1992, 894,777 insurance claims for barium enema examination and lower gastrointestinal endoscopy were retrospectively examined. Changes in use were investigated. Use of proctosigmoidoscopy and flexible sigmoidoscopy, two office-based endoscopic procedures, was also examined. RESULTS: Use of diagnostic colonoscopy increased from 191 to 406 services per 100,000 persons; colonoscopy with biopsy, from 77 to 183 services; and colonoscopy with lesion removal, from 77 to 202 services. Barium enema examination use declined from 929 to 511 services per 100,000 persons; diagnostic proctosigmoidoscopy, from 854 to 193 services; and diagnostic flexible sigmoidoscopy, from 656 to 620 services. Increases in use of colonoscopy in patients aged younger than 40 years were greater than overall increases. CONCLUSION: Colonoscopy has been replacing barium enema examination as the initial colorectal examination since 1985. Increased use of colonoscopy in patients with lower risk of neoplasia suggests that indications have become overly broad.

Adult↗
PubMed1994

Pelvic marrow in adults.

The appearance of hematopoietic marrow in magnetic resonance (MR) imaging is variable and differences between normal and pathologic marrow may be subtle. To aid in the evaluation of this problem, we reviewed 82 consecutive pelvic MR examinations in men with no evidence of osseous metastases. Images were evaluated with regard to the overall fraction of residual hematopoietic marrow present and the characteristics of this marrow. The patient population in our study was older (mean age 66 years) than the patient populations in previous papers documenting normal marrow patterns. The overall amount of hematopoietic marrow present was less in this older patient population, with 80% of patients having less then 40% residual hematopoietic marrow. A consistent pattern of morphologic change was noted as hematopoietic marrow converted to fatty marrow with increasing age. Initially, hematopoietic marrow tended to appear diffuse, heterogeneous, and with poorly defined margins on MR imaging. As conversion to fatty marrow continued, hematopoietic marrow became more focal and sharply defined, usually in the form of islands of residual hematopoietic marrow. Periarticular hematopoietic marrow predominated in the sacroiliac region (72% of patients) with little residual hematopoietic marrow noted in the symphysis pubis (5%) and hip joints (30%). Hematopoietic marrow persisted longer in juxtacortical locations (87%), was always symmetric (100%), remained less intense than fat on T2-weighted images (100%), and usually had a central focus of fat (98%). These morphologic criteria may be of value in establishing the MR appearance and patterns of marrow in the pelvis, and in the recognition and confident diagnosis of foci of hematopoietic marrow.

Adult↗
PubMed1994

Prospective comparison of external sphincter balloon dilatation and prosthesis placement with external sphincterotomy in spinal cord injured men.

The purpose of our investigation was to compare external sphincterotomy, the traditional method of treatment of detrusor-external sphincter dyssynergia (DESD), with two newer methods, balloon dilatation or internal stenting of the external sphincter. Sixty-one spinal cord injured (SCI) men were prospectively evaluated. The indications for treatment were DESD and voiding pressure greater than 60 cmH2O demonstrated during video-urodynamic study. Twenty patients were treated with balloon dilatation of the external sphincter, 26 with an internal stent prosthesis, and 15 with traditional external sphincterotomy. Age and duration of SCI were similar among the three treatment groups. A significant decrease in both voiding pressure and residual urine from presurgery levels persisted during the follow-up period of 3 to 26 months (mean, 15 months) in all three groups. Bladder capacity remained constant, renal function improved or stabilized, and autonomic dysreflexia (AD) improved in all three groups. Balloon dilatation and prosthesis placement are associated with a significantly shorter length of surgery (p = 0.045), length of hospitalization (p = 0.005), decrease in hospitalization cost (p = 0.01), and decrease in hemoglobin postoperatively (p = 0.046) when compared to external sphincterotomy. Complications of stent insertion included device migration (three patients) and secondary bladder neck obstruction (two patients). In the balloon dilatation group, three recurrent sphincter obstructions, one case of bleeding requiring transfusion, and one case of bulbous urethral stricture occurred. After external sphincterotomy, two patients developed recurrent obstruction, two required blood transfusion, and 1 patient noted erectile dysfunction. Balloon dilatation and prosthesis placement both proved to be as effective as external sphincterotomy in the treatment of DESD.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Early knowledge of object motion: continuity and inertia.

Experiments investigated whether infants infer that a hidden, freely moving object will move continuously and smoothly. Infants aged 6 and 10 months, like the 4-month-old infants in previous experiments, inferred that the object's path would be connected and unobstructed, in accord with the principle of continuity. In contrast, 4- and 6-month-old infants did not appear to infer that the object's path would be smooth, in accord with the principle of inertia. At 8 and 10 months, knowledge of inertia appeared to be emerging but remained weaker than knowledge of continuity. These findings are consistent with the view that common sense knowledge of physical objects develops by enrichment around constant core principles.

Cognition↗
PubMed1994

Distributional patterns of multiple sclerosis brain lesions. Magnetic resonance imaging--clinical correlation.

Forty-one patients with multiple sclerosis were studied with magnetic resonance imaging (MRI) and a battery of neuropsychological tests to determine the pattern of lobar distribution of lesions in the relapsing-progressive and relapsing-remitting forms of the disease. Correlation of lesions with the patient's cognitive and emotional dysfunction was also obtained. The results of this study indicate that patients with relapsing-progressive multiple sclerosis are characterized by the large or coalescent lesions located predominantly in the periventricular area. These lesions were more frequently found in the parietooccipital areas and were accompanied by significant cognitive dysfunction and severe personality changes. The patients with relapsing-remitting disease, however, were characterized by punctiform or small discrete lesions predominantly located in the intermediate and subcortical areas. These lesions were more frequently seen in the parietooccipital regions and the patients had significantly less severe cognitive and emotional involvement than did the patients with relapsing-progressive disease. Recognition of these patterns was easily accomplished by MRI. In this investigation MRI studies were utilized as an index of the pathological changes occurring at one point in time in the evaluation of the disease. Only repeated MRI studies and continuous clinical observation can establish the final diagnosis.

Adult↗
PubMed1994

Imaging findings in mucin-containing carcinomas of the breast: correlation with pathologic features.

OBJECTIVE: Breast carcinomas may contain varying quantities of extracellular mucin. The purpose of this study was to correlate the mammographic and sonographic appearance of mucin-containing carcinomas of the breast with the histologic features of these tumors. MATERIALS AND METHODS: The tumor registry and breast imaging files at our institution identified 34 women with 37 mucin-containing breast carcinomas for which mammographic and histologic slides were available for review. By consensus, two radiologists determined the mammographic margin characteristics (circumscribed, microlobulated, indistinct, spiculated) and, when available, the sonographic properties of the carcinomas. Doubling time in days was estimated from sequential mammograms when possible. A pathologist reviewed the histologic slides and divided the 37 carcinomas into three categories based on the percentage by volume of mucin seen: pure mucinous (> or = 90% mucin), 23 cases; moderately mucinous (< 90% and > 30% mucin), seven cases; and minimally mucinous (< or = 30% mucin), seven cases. To determine the contribution of varying percentages of mucin to the radiologic appearance of the tumors, the margin characteristics were correlated with the histologic percentage of mucin, microscopic margin appearance (displacing or infiltrating), nuclear grade (I, II, III), and lymph node status. RESULTS: Tumors with circumscribed and microlobulated margins on mammography had a higher percentage of mucin histologically (p < .01; chi 2). A trend of slower growth rate on mammograms, lower histologic nuclear grade, and less frequent axillary node involvement were also seen in tumors with a higher percentage of mucin. Spiculated mammographic margins were seen when there were decreasing volumes of mucin and when tumor margins histologically were infiltrating; these tumors had higher nuclear grades and more frequent axillary node involvement (p < .01). CONCLUSION: The radiologic and pathologic correlation of mucin-containing breast carcinomas demonstrates that lesions with higher percentages of mucin have mammographic appearances that reflect less aggressive histologic margins, lower nuclear grades, and slower growth rates. Carcinomas that have small percentages of mucin have mammographic and histologic characteristics of more aggressive, invasive ductal carcinomas.

Adenocarcinoma, Mucinous↗
PubMed1994

Endorectal color and duplex imaging of the normal rectal wall and rectal masses.

This study investigates the ability of endorectal ultrasonography aided by color flow and pulse wave Doppler techniques to identify submucosal arterial plexuses of the normal rectal wall and to detect vessels supplying rectal wall masses. Color flow and pulsed wave Doppler analysis of 62 normal submucosal arterial plexuses and vessels feeding rectal wall masses (one rectal endometriosis and seven rectal cancers) was performed. The color signals from normal submucosal arterial plexuses and the one case of rectal endometriosis were judged to be sparse or decreased in comparison to color signals from rectal cancers. The median and mean P1 values for normal submucosal arterial plexuses were significantly greater than those for the central feeding vessels or small peripheral vessels within rectal masses. Our experience with color and duplex endorectal ultrasonography suggests that different vascular structures exist in normal persons compared to those in rectal wall masses. Pathologically, rectal cancers possess vessels with and without a smooth muscle layer, which may produce the high and low resistance signals identified by pulse Doppler.

Adult↗
PubMed1993

The patellar tendon: thickening, internal signal buckling, and other MR variants.

We studied the range of appearance of asymptomatic patellar tendons and evaluated the effect of age, weight, joint effusions, and anterior cruciate ligament (ACL) tears on this tendon. One hundred and seventy-three patellar tendons in asymptomatic patients were studied at 1.5 tesla. Sagittal short and long TE images were evaluated in regard to tendon thickness, ratio of thickness of patellar to quadriceps tendons, frequency, location, and severity of intratendon signal, and frequency and severity of tendon buckling. Results were correlated with patient age, sex, weight, the presence of ACL tears, and relative volumes of joint fluid. The mean thickness of the patellar tendon was 0.52 cm. The patellar to quadriceps tendon ratio was 0.72. The patellar tendon frequently (74%) had focal areas of signal apparently within it. This signal was usually subtle, V-shaped (95%), and seen posteriorly in the proximal end of the tendon (82%). Intratendon signal was also seen commonly in the inferior aspect of the tendon (32%). This signal intensity did not increase with greater T2-weighting (99%). Buckling of the patellar tendon was a frequent asymptomatic variant (71%) but was also associated with joint effusions (p < 0.01) and ACL tears (p = 0.01). Buckling, intratendon signal, and tendon thickness increased with weight and age. Variation of the magnetic resonance appearance of the patellar tendon is frequent. Many of these changes appear to represent subclinical degeneration. Buckling of this tendon also may occur secondary to joint effusions or ACL tears.

Adolescent↗
PubMed1991

Fatty liver. Chemical shift phase-difference and suppression magnetic resonance imaging techniques in animals, phantoms, and humans.

In vitro animal and human models were used to evaluate the potential of chemical shift magnetic resonance imaging (MRI) for assessing fatty liver. Phantoms of varying fat content were created from mayonnaise-agar preparations. Fatty liver was induced in eight rats by feeding them ethanol for three to six weeks (36% of total calories), whereas eight control rats were fed a normal diet. T1-weighted in-phase and opposed-phase MR images were obtained of the phantoms animals, and 28 human subjects. Additional images obtained in animals included long TR images with in-phase and opposed-phase technique, and hybrid chemical shift water and fat suppression. The rats were killed and histologic status was graded blindly by a hepatopathologist as normal, mild, moderate, or severe fatty change, for correlation with MR grading. Quantitative analysis of MR images included fat signal fraction for animals, and relative signal decrease between in-phase and opposed-phase images for phantom and human data. Phantom in-phase signal increased linearly with respect to fat content, whereas opposed-phase signal decreased linearly. MRI and histologic grading of rat livers were highly correlated, especially when based on water suppression images (r = 0.91, P = .0001). Opposed-phase images were also highly correlated, while fat suppression images were less effective. There was no overlap between MR-derived fat fractions for control (2.6%-5.7%) versus ethanol-fed rats (7.7%-17.9%, P = .0002). Human liver considered to be fatty by visual inspection (n = 8) had higher relative signal decrease than nonfatty liver (n = 22) (P less than .001). Phantom, animal, and human data demonstrate that comparison of T1-weighted in-phase and opposed-phase images is both practical and sensitive in the detection and grading of fatty liver.

Adult↗
PubMed1990

Interhemispheric fissure width in neonates on ECMO.

The neurosonograms of fifty-eight patients treated over a four-year period with ECMO support were retrospectively reviewed for analysis of changes in interhemispheric (IHF) width while on ECMO. To correlate these measurements with patterns of development of total body edema as reflected by chest wall thickening on portable chest radiographs, patients were divided into three categories based on the pattern and severity of body edema development. Patterns of IHF widening were compared between these categories, and to the pattern of development of chest wall edema within each category. Results indicate that IHF width tends to progressively increase during ECMO and that the pattern of IHF widening tends to parallel development of overall body edema. Additionally, IHF widening was found to resolve following termination of ECMO support, as demonstrated on follow-up cranial CT examinations. Our results suggest that IHF widening in infants on ECMO is an intracranial manifestation of the generalized edema accumulation that frequently occurs during ECMO.

Analysis of Variance↗
PubMed1990

Estimation of radiation risk from screening mammography: recent trends and comparison with expected benefits.

On the basis of recent epidemiologic studies, the National Institutes of Health in 1985 provided a new estimate for radiation risk to the breast that employed a relative risk model and acknowledged greater dependence on age at exposure. Lifetime risks from a single mammogram may be calculated from this estimate and are lower than those based on the previous 1977 National Cancer Institute estimate. Possible years of life expectancy lost from annual mammography beginning at age 40 years may also be calculated and are negligible compared with estimates for years of life expectancy gained from such screening.

Age Factors↗
PubMed1990

Diagnostic quality of portable abdominal radiographs in neonates with necrotizing enterocolitis: digitized vs nondigitized images.

Digital manipulation of radiographic images has prompted significant interest because of the potential for improving image quality and diagnostic accuracy. We compared conventional and digital radiographs in the evaluation of neonatal necrotizing enterocolitis (NEC). Fifty abdominal radiographs in neonates with suspected or autopsy-confirmed NEC and 50 similar radiographs of neonates without suspicion of NEC were digitized. Definition of intraabdominal anatomy was optimized by window width and level adjustment. Hard-copy radiographs of the digitally manipulated images were then produced by a laser printer. Twelve general radiologists each evaluated, without benefit of clinical information, a random mixture of 50 cases of NEC and normal controls, with both conventional and digital images for each case, for a total of 100 radiographs reviewed. Each image was evaluated for overall suspicion of NEC and the presence and severity of six radiographic signs of NEC. The radiologists also rated their confidence in their assessments. The results were compared with those from a similar analysis by an experienced pediatric radiologist to ensure validity of image evaluation. No statistically significant differences were found between the conventional and digital imaging formats for the assessment of the signs of NEC (p = .15) or for determination of the overall suspicion of NEC (p = .07). Our results show the digitized and the conventional, nondigitized radiographs to be at least equally useful for evaluating the radiographic signs of NEC and suggesting an appropriate diagnosis.

Enterocolitis, Pseudomembranous↗