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Biomedical subjects

M A Klein

Publications and source records attributed to M A Klein.

At least 73 records · Page 4Linked to original sources
PubMed1990

Surface coil FLASH magnetic resonance imaging of the fasting and secretin-stimulated pancreas.

The purpose of this study is to investigate the response of the pancreas to secretin stimulation using magnetic resonance imaging (MRI). Using the Siemens 1.0 T Magnetom and a Helmholtz surface coil, single breath FLASH-MRI of the normal fasting pancreas was performed in the prone position, both before and after a 20-minute period after intravenous (IV) bolus injection of secretin (2 cu/kg). T2*-weighted fast low-angle shot sequences (TR = 150 mseconds; TE = 30 mseconds; flip angle = 10 degrees; matrix = 256 X 256; acquisitions = 2) demonstrated an immediate response manifested by a significant distension of the duodenum with fluid secreted by the pancreas, as well as a gradual decline of the pancreas/muscle signal intensity (SI) ratio over time. Twenty minutes after secretin administration, the mean percent decrease of the pancreas/muscle SI ratio in six volunteers was 11.6 +/- 6.4 (1-STD). This is statistically significant (P less than .003) given a mean percent increase of the pancreas/muscle SI ratio of 1.6 +/- 4.8 (1-STD) in five volunteers 20 minutes after bolus injection of saline (control). Although significant duodenal distension is easily demonstrated after secretin administration, the decrease of the relative pancreatic SI over time is visually subtle. Further work is needed to enhance imaging of the physiologic response of the pancreas using even more rapid imaging techniques.

Adult↗
PubMed1990

Sonographic and Doppler features of infantile hepatic hemangiomas with pathologic correlation.

The sonograms of five patients with a diagnosis of infantile hepatic hemangioma were retrospectively reviewed to analyze their sonographic and Doppler characteristics. Three patients had single lesions, whereas two had multifocal involvement. All lesions except one were hypoechoic, well-circumscribed, and solid; the exception was hyperechoic. Findings of high flow, ie, large draining veins, an abrupt change in aortic caliber, and the presence of Doppler signal throughout the lesion were seen in three of five patients. The sonographic findings correlate well with the pathologic findings of multiple vascular channels separated by fibrous septa. The major differential diagnosis of infantile hepatic hemangioma includes hepatoblastoma and metastatic neuroblastoma. Although some of their sonographic features may simulate a hemangioma, large draining veins and changes in aortic caliber are not reportedly seen. Doppler flow was not seen in either of these malignant neoplasms in our study and, to date, has only been reported peripheral to three cases of hepatoblastoma and not at all in metastatic neuroblastoma. We propose an algorithmic approach dependent upon the sonographic-Doppler appearance.

Hemangioma, Cavernous↗
PubMed1989

Hepatic involvement in Hodgkin's disease. Clues to histologic diagnosis.

The hepatic histopathology was studied in 125 patients with Hodgkin's disease to determine whether there are any features other than Reed-Sternberg (RS) cells that might aid in the diagnosis of hepatic involvement by the neoplastic process. Liver biopsy specimens from 41 patients with Hodgkin's disease in the liver were compared with biopsy specimens from 84 patients without hepatic involvement. Patients with hepatic involvement by Hodgkin's disease are much more likely to have histologic evidence of portal infiltrates larger than 1 mm in diameter (78% versus 1%), acute cholangitis (85% versus 4%), portal edema (90% versus 8%), and portal infiltrates with a predominance of atypical lymphocytes (78% versus 12%) than patients with Hodgkin's disease who do not have hepatic involvement. When these features are observed alone or in combination in a liver biopsy specimen from a patient with proven or suspected Hodgkin's disease, a diligent search for RS cells is indicated, with serial sections and repeat biopsy if necessary.

Cholangitis↗
PubMed1989

Cocaine abuse: neurovascular complications.

In a review of the records of 3,712 drug abusers, 13 patients were identified with neurologic deficits attributable to the use of cocaine. Ischemic manifestations were the most frequent, occurring in seven (54%) patients, with a mean age of 34.2 years. Three (23%) patients had subarachnoid hemorrhage, and three (23%) had intracerebral hemorrhage. Three patients from other institutions were included in the analysis, for a total of 16 patients, (eight with cerebral ischemia, four with subarachnoid hemorrhage, and four with intracerebral hemorrhage). Of the six patients with head computed tomographic findings of cerebral infarction, five had subcortical infarcts. Two of the four patients who presented with a subarachnoid hemorrhage had a congenital intracranial aneurysm. One of the four patients with an intracerebral hemorrhage had an underlying arteriovenous malformation. The mechanism through which these complications occur is not completely understood. Factors that may play a role include the acute hypertensive response that occurs with cocaine use as well as disordered neurovascular control.

Adult↗
PubMed1988

Salvage therapy in metastatic adult Wilms' tumor.

Adult Wilms' tumor is a rare and aggressive malignancy. Despite multimodality therapy for all stages of disease, the majority of patients develop fatal metastases. Little information is available on effective salvage therapy. The current report describes a 38-year-old man who had Stage I disease. Pulmonary metastases developed after radical nephrectomy and tumor bed irradiation while receiving adjuvant chemotherapy. He achieved a complete remission lasting 8 months with a combination chemotherapy regimen of cyclophosphamide, vinblastine, dactinomycin, and cisplatin. After isolated pulmonary relapse, he received whole-lung irradiation and remained disease-free 4.5 years after diagnosis. The previously reported results of therapy in metastatic or unresectable adult Wilms' tumor are reviewed, and the current case of effective salvage therapy is documented.

Adult↗
PubMed1988

Fatal esorubicin-induced cardiomyopathy: report of a case and review of the literature.

A case of fatal dilated cardiomyopathy induced by esorubicin (ESO) at a total dose of 740 mg/m2, given in 27 doses over 650 days, is reported. The sudden onset, rapid clinical deterioration, and fatal outcome are detailed. The outcome was not predicted by serial rest ejection fractions or clinical signs. The data from animal studies, phase 1 and phase 2 clinical testing, are reviewed, demonstrating the almost complete absence of reports of ESO-induced cardiotoxicity. Studies reviewing ejection fractions and myocardial biopsy scores show that ESO can be cardiotoxic and may produce fatal dilated cardiomyopathy.

Cardiomyopathies↗
PubMed1988

Generalized dysfunction in clinic and nonclinic families: a comparative analysis.

This study examined the relationship of self-reported marital distress to parental descriptions of emotional or behavioral disturbance of their children using two multidimensional measures of relationship satisfaction and personality functioning in children and adolescents. Data were collected from three independent samples of couples in marital therapy, parents of psychiatrically hospitalized children or adolescents, and nonclinic couples from the general population. Using a split-half cross-validation procedure, parents' reports of their children's emotional or behavioral difficulties were consistently and positively related to their descriptions of dissatisfaction with the parent-child relationship and with reports of spousal conflict over childrearing, but not with measures of global marital distress or spousal conflict in areas not related to childrearing. Discrepancies in spouses' descriptions of their marriage or child were unrelated to individual measures of relationship functioning or child/adolescent psychopathology. Implications for clinical assessment and future research are discussed.

Adolescent↗
PubMed1988

Recognizing tympanostomy tubes on temporal bone CT: typical and atypical appearances.

Myringotomy with placement of a tympanostomy tube is a common surgical procedure. Although CT is not performed to evaluate these tubes, recognizing and accurately reporting their presence are important for a number of reasons. These include misidentification of the tube as a foreign body or a dislocated ossicle, misidentification of debris or normal ossicles as a tympanostomy tube, confirmation of the presence of a tube not seen on otoscopic evaluation, stimulation of careful search for cholesteatoma, and documentation of intervention. The purpose of this study is to show the CT appearance of tympanostomy tubes and to determine factors that make their identification on CT difficult. We reviewed all CT studies of the temporal bone performed over a 1-year period to determine the presence and appearance of tympanostomy tubes. Of the 118 CT scans evaluated, 19 patients (16%) had 34 tympanostomy tubes; of these 34 tubes, 13 (38%) had CT features that hindered identification of the tubes. Factors that resulted in obscured tubes, in order of frequency, included surrounding fluid, technical problems such as motion and artifacts, and atypical location. By knowing the appropriate location and CT appearance of tympanostomy tubes, misidentification of the tubes can be avoided.

Adolescent↗
PubMed1987

Black adolescents' attitudes toward and use of alcohol and other drugs.

Substance use and misuse has become a major problem in recent years. Although there has been research conducted concerning the use of substances by adolescents, little attention has been focused on the Black adolescent. The purpose of this research was to identify the attitudes of Black adolescents toward substances, their level of use, and the extent of their participation in alternative activities. Results indicated that there was a high percentage of students who reported negative attitudes toward substances, that actual use levels were extremely low, and that students spend a considerable amount of time involved in alternative activities.

Adolescent↗
PubMed1985

Non-Hodgkin's lymphoma after successful therapy of small cell lung carcinoma.

A patient is presented who developed a diffuse mixed lymphoma after successful treatment of small cell undifferentiated carcinoma of the lung. The patient was treated with cytotoxic chemotherapy and irradiation for the lung cancer, and had no recurrence during 6 years with no treatment. He then developed stage IV lymphoma. The relationship between these two cancers and the occurrence of treatment-induced second malignancies in small cell carcinoma are discussed.

Aged↗
PubMed1981

Binaural edge pitch.

The Huggins pitch effect is created by dichotic broadband noise with interaural phase varying from 0 to 2 pi over a narrow frequency region. The sensation of pitch, corresponding to the frequency of the phase shift region, is usually understood as the result of a binaural differencing operation. We report here a pitch effect created by dichotic broadband noise with interaural phase varying from 0 to pi over a narrow boundary region, creating an edge in a difference channel. We call this effect Binaural Edge Pitch. For experienced listeners the effect is similar in nature and strength to the Huggins pitch. It is strongest for boundary frequencies in the 350--800 Hz range. Pitch matching experiments in this range find that the spread of matches in 1%--2% of the boundary frequency and that the pitch is 4% higher or lower than the boundary frequency. This shift is identical to the shifts which we find for the pitch of high-pass and low-pass noise bands. The correspondence argues strongly for an explanation of the Binaural Edge Pitch in terms of the Equalization--Cancellation Model of binaural processing, and pitch derived from central spectrum.

Acoustic Stimulation↗
PubMed1980

Theory of frequency modulation detection for low modulation frequencies.

There is general agreement that the frequency difference limen measured in a two-sine-tone frequency discrimination experiment is smaller than that measured in a frequency modulation (FM) experiment. We present a model of frequency modulation detection for low modulation frequencies, within the framework of signal detection theory, which accounts well for the observed difference between frequency discrimination experiments and FM detection experiments. The FM detection model also predicts psychometric functions for detection of FM with different modulation waveforms. FM detection experiments with square, sine, trapezoid, and triangle FM are in reasonable agreement with the model predictions.

Acoustic Stimulation↗
PubMed1977

"Lennert's lymphoma" with transformation to malignant lymphoma, histiocytic type (immunoblastic sarcoma).

Two cases of a recently described lymphoproliferative disorder called "Lennert's lymphoma" are presented. In both cases, the proliferation evolved into a frank malignant lymphoma of large lymphoid cells. This phenomenon has not been previously reported to occur in this disease. Immunohistologic study of the biopsy material in both cases suggest that it may be a T-cell proliferation. The possibility that "Lennert's lymphoma" is not a neoplasm but an abnormal immune reaction with similarities to angioimmunoblastic lymphadenopathy is raised. Whatever its nature, the potential for "Lennert's lymphoma" to transform into a frankly malignant tumor is documented.

Aged↗