PubMed Health⌕ Search

Biomedical subjects

H L Cohen

Publications and source records attributed to H L Cohen.

At least 19 recordsLinked to original sources
PubMed1998

Effects of ethanol on temporal recovery of auditory-evoked potentials in individuals at risk for alcoholism.

The present investigation examined the effects of placebo (P), low dose (LD), and high dose (HD) ethanol on auditory event-related potential (AEP) recovery functions in a group of males at high risk to develop alcoholism (HR; n = 23, mean = 22.3 years) and a low risk (LR; n = 27, mean = 23.0 years) control group. Condition order was randomized, with one condition (P, LD, or HD) per day and a minimum 1-day interval between conditions. For each subject, both blood alcohol levels (BALs) measured via breathalyzer, and event-related potentials recorded with the entire 10/20 International System, were assessed prior to and at mean intervals of 20, 60, 90, and 130 min after P, LD, or HD administration. A series of binaural auditory stimuli with randomly interposed interstimulus intervals of 0.5, 1.0, and 10.0 sec were used to elicit the N100 and P200 components of the AEP. Between-groups comparisons indicated that ethanol elicited risk group differences in recovery functions not present at baseline. The differences were manifested in the HR group as larger decrements in P200 amplitude during the ascending blood alcohol curve (acute sensitivity) and more rapid returns of both N100 and P200 to baseline levels during the descending blood alcohol curve (acute tolerance). These findings support Newlin and Thomson's (1990) Differentiator Model, suggesting that LR and HR individuals are differentially sensitive to the effects of ethanol.

Adolescent↗
PubMed1997

Neuroelectric correlates of response production and inhibition in individuals at risk to develop alcoholism.

P300 recordings were made from males at high risk (HR) for alcoholism and low-risk (LR) controls, participating in a visual go/no go reaction time paradigm. The go (button press) and no go (inhibit response) stimuli were large and small forms of the same letters. The LR group had significantly larger go than no go P300 amplitudes in the central, parietal, and temporal regions; the HR group manifested no response differences in any region. In the LR group compared to the HR group, both go and no go response amplitudes were larger over the entire head; no group differences in latencies were observed in any region. Surface energy magnitudes paralleled P300 amplitudes and were also larger in the LR group during both go and no go trials. Our findings indicate that HR individuals manifest widespread P300 amplitude deficits while performing a simple information-processing paradigm. These deficits, which may reflect genetic influences, preceded the onset of alcoholism and may function as a phenotypic marker for its development.

Adult↗
PubMed1997

Diagnostic imaging in pediatric AIDS.

The manifestations of acquired immune deficiency syndrome (AIDS) in children are mainly secondary to opportunistic infection, lymphoproliferative diseases, and AIDS-related neoplasms. This article reviews the pathologic findings of various disorders afflicting children with AIDS and emphasizes the imaging of these disorders. Although many of the radiologic findings are not specific for a particular infection or neoplasm, the differential diagnostic possibilities for an abnormality can be narrowed down significantly with proper clinical correlation and knowledge of the imaging findings and pathologies specific to children with AIDS.

Acquired Immunodeficiency Syndrome↗
PubMed1997

Ultrasonographic diagnosis of ectopic pregnancy: importance of transabdominal imaging.

Endovaginal sonography has greatly improved the diagnostic evaluation of suspected ectopic pregnancy. Some authors suggest imaging solely by endovaginal technique for diagnosis. We perform both a transabdominal scan for a global view of the pelvic and abdominal contents and an endovaginal sonographic examination for a higher resolution and focused view of the gynecologic structures. We report three patients with negative endovaginal examinations who had obvious ectopic pregnancies on our subsequent transabdominal examination. These cases remind us of the valuable information that can be obtained with the transabdominal approach and the complementary role it plays with endovaginal sonography.

Abdomen↗
PubMed1997

Neurophysiological correlates of response production and inhibition in alcoholics.

Scalp recordings of the P300 component of the event-related potential were made from a group of medication-free, chronic male alcoholics and a control group, participating in a visual Go/No Go reaction time paradigm. Subjects were presented with large and small forms of the letters T and V. The large forms (Go stimuli) required a button press with either the left or right hand, whereas the small forms (NO Go stimuli) required response inhibition. Recordings were made from 31 electrodes that, for statistical analyses, were grouped into five regions: frontal, central, parietal, occipital, and temporal. The results indicated that, in each of the five regions, both Go and NO Go response amplitudes were larger in the controls than in the alcoholics. No group differences in latency were observed in any region. Surface energy (Wang et al., Brain Topogr. 6:193-202, 1994) magnitudes paralleled P300 amplitudes and in the controls, compared with the alcoholics, were larger during both Go and No Go trials. Our findings suggest that abstinent, chronic alcoholics differ electro-physiologically from control individuals. These differences are manifested as widespread reductions in P300 amplitudes during the performance of a simple information processing paradigm. The reduced amplitudes may reflect a deficiency in an inhibitory mechanism proposed to underlie P300 generation.

Adult↗
PubMed1996

Endodermal sinus tumor of the ovary: imaging evaluation.

OBJECTIVE: Endodermal sinus tumor of the ovary is a rare complex malignant tumor that occurs in young women. We performed this study to determine the imaging characteristics of this tumor. CONCLUSION: Endodermal sinus tumor of the ovary presents as a large complex abdominal mass that can be predominantly cystic and should be considered in the differential diagnosis of complex abdominal masses in girls and young women. In addition, upon encountering a mass with these imaging characteristics in the proper clinical setting, serum alpha-fetoprotein levels should be measured to help make a presurgical diagnosis and to obtain a baseline value.

Adolescent↗
PubMed1995

Isolated fetal hydronephrosis: beware the effect of bladder filling.

The aim was to assess the role that fetal bladder size has in the determination of fetal hydronephrosis. Forty-three fetuses were evaluated for fetal hydronephrosis in the second trimester of pregnancy. Anteroposterior measurements of the renal pelvis were obtained with a full bladder and again when the bladder emptied in each fetus. Statistical analysis was performed using the Spearman rank order correlation coefficient to assess the relationship between bladder status and renal dilation. The anteroposterior size of the fetal renal pelvis diminished from 6.8 +/- 1.8 mm on a full bladder scan to 4.5 +/- 1.6 mm when the bladder was emptied (P < 0.001). Fifty-three per cent of the fetuses whose renal pelvic measurements were 5 mm or more on a full bladder scan had normal-appearing renal pelvises when their bladders emptied. The status of the fetal bladder should be considered when evaluating fetal hydronephrosis.

Diagnostic Errors↗
PubMed1995

Auditory P300 in young alcoholics: regional response characteristics.

An auditory oddball paradigm was used to record the P300 component of the event-related potential (ERP) in a group of medication-free, chronic male alcoholics (n = 51, mean = 32.2) and a control group (n = 25, mean = 27.2). Each subject received a binaurally presented series of high (1600-Hz)- and low (600-Hz)-frequency tones. The designation of the rare tone (0.125 probability) was alternated across subjects. When the subject detected the rare tone, he made a button press as quickly as possible to record his reaction time. Scalp recordings using the entire 10/20 System, as well as interpolated placements, were made from 31 electrodes. For purposes of statistical analyses, five regional electrode groups were created: F (frontal), C (central), P (parietal), O (occipital), and T (temporal). The results of MANOVA indicated that control P300 amplitudes were significantly greater than those of the alcoholics in all five regions, whereas there were no P300 latency differences between groups in any region. Regional response differences between the groups were also compared with measures of surface energy (SE) (Wang et al., 1994). SE is a recently developed, reference-free global field measure that uses the entire scalp potential field and treats potentials at different positions differently. SE was significantly reduced in the alcoholics compared with the controls in both the C (p < 0.0003) and P (p < 0.0006) regions, although there were no differences in its distribution.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Neurosonographic findings in full-term infants born to maternal cocaine abusers: visualization of subependymal and periventricular cysts.

Neuroanatomical abnormalities have been linked to maternal cocaine abuse since Chasnoff et al's report of cerebral infarction in a single full-term offspring of a cocaine-abusing mother. Neurosonography was performed on 18 full-term offspring of cocaine-abusing mothers and 19 age-matched controls to look for possible abnormalities. There were no cases of infarction or intraparenchymal or intraventricular hemorrhage. There were, however, 6 patients with abnormalities among the cocaine-abusing group: 5 patients with unilateral or bilateral germinal matrix cysts and 3 patients with subtle cystic or predominantly cystic areas in watershed zones consistent with periventricular leukomalacia.

Adult↗
PubMed1994

Prenatal diagnosis of focal nodular hyperplasia of the liver.

A case of focal nodular hyperplasia of the liver presenting in a 36-week-old fetus is reported. The tumour appeared on antenatal ultrasound as a 4.0 cm x 3.0 cm x 2.7 cm hypoechoic mass at the periphery of the right lobe of the liver. Colour Doppler imaging showed it to have prominent vascularity. Postnatally, sonography confirmed the presence of a vascular mass within the liver. The tumour was removed at laparotomy and was diagnosed as an area of focal nodular hyperplasia on histopathological examination.

Adult↗
PubMed1994

Pediatric HIV infection: an imaging update.

Infection with the human immunodeficiency virus (HIV) can produce a broad range of illness, including opportunistic infections, lymphoproliferative diseases, and benign and malignant neoplasms. Each conditions has its own spectrum of imaging findings. This paper will highlight those findings in children suffering from HIV infection/AIDS. We will stress the findings in the more frequently involved organ systems and those that are unique to children.

AIDS-Related Opportunistic Infections↗
PubMed1994

Posterior urethral valve: transperineal US for imaging and diagnosis in male infants.

PURPOSE: To compare routine pelvic and transperineal scanning in the ultrasonographic (US) diagnosis of posterior urethral valve (PUV). MATERIALS AND METHODS: Longitudinal and transverse transperineal views were obtained in addition to routine renal and transvesicle views in the prospective US evaluation of 10 male infants (aged 2 days to 6 weeks) clinically suspected of having PUV. High-frequency (5.0- and 7.5-MHz) transducers were used. RESULTS: Five of the boys proved to have PUV. Each had urethral dilation clearly imaged at transperineal US. Only two of these boys had urethral dilatation imaged with the transvesicle approach. In three of the boys, a linear area of echogenicity, consistent with a valve, was imaged, but only with the transperineal approach. The other five boys had no urethral dilatation noted at transperineal or transvesicle US and proved to not have PUV. CONCLUSION: Transperineal imaging can aid in the diagnosis of PUV at US. Transperineal US may enable imaging of the valve itself.

Congenital Abnormalities↗
PubMed1994

Gastrointestinal manifestations of AIDS in children.

The gastrointestinal manifestations of AIDS in children are related to opportunistic infections, lymphoproliferative disease, and cancer. The infections that affect the gastrointestinal tract at different sites also occur in patients without AIDS. However, in children with AIDS, the infections are more severe, often relapse, and are harder to eradicate. Candidiasis is the most common infection in the esophagus, but infections caused by herpes simplex virus and cytomegalovirus also are common. Radiologic findings include ulcerations, a cobblestone appearance, and disordered motility. Gastritis and enteritis are usually caused by cytomegalovirus. Lesions produced by this virus include ulcerations caused by ischemic necrosis as a result of vasculitis. Barium studies show increased nodularity and effacement of mucosa. Other organisms (typically found in all immunocompromised patients) include Mycobacterium avium-intracellulare, Mycobacterium tuberculosis, Campylobacter, Giardia, and Cryptosporidium. Colitis and proctitis are caused by many of the same enteric pathogens. Cytomegalovirus is the most virulent, causing necrosis, perforation, and often death. Lymphoma, smooth muscle tumors, and Kaposi's sarcoma are the most common neoplasms encountered in children with AIDS.

AIDS-Related Opportunistic Infections↗
PubMed1994

Advances in perinatal neurosonography.

Progress in neurosonographic diagnosis of fetuses and neonates has continued as clinical and imaging experience has increased, technology and technique have improved, and transducers for Doppler and color Doppler imaging have become more available. This review discusses some of the advances in perinatal neurosonographic diagnosis.

Central Nervous System Diseases↗