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Biomedical subjects

R Zimmerman

Publications and source records attributed to R Zimmerman.

At least 91 records · Page 5Linked to original sources
PubMed1988

MRI demonstrates descending transtentorial herniation.

Descending cerebral transtentorial herniation (DTH) is a serious and often fatal complication of intracranial mass lesions. The condition can be inferred from clinical neurologic signs, but has not been visualized during life. Using midsagittal magnetic resonance images (MRIs), we compared vertical brainstem position on 50 images from normals and 21 images from 15 clinically stable patients with large supratentorial tumors. The length of Twining's line (T), the perpendicular distance from T to the pontomesencephalic junction (T-PMJ), and from T to the apex of the midbrain aqueduct (T-A) were measured. We also measured lateral shifts of the diencephalon and midbrain on axial images. T-PMJ decreased from 2.04 +/- 0.06 mm in normals to 0.94 +/- 0.2 mm in patients with large cerebral tumors (p less than 0.0001). Similarly, T-A decreased from 6.35 +/- 0.13 mm in normals to 4.83 +/- 0.35 mm in patients (p = 0.001). Lateral diencephalic-midbrain shifts often accompanied DTH but to an unpredictable degree. Either lateral or downward brainstem shift could occur alone and did not necessarily produce specific neurologic signs or an altered state of consciousness. Anatomic DTH occurs in life, it can be quantified with MRI, and in slowly developing cerebral mass lesions the process can precede the appearance of neurologic signs and symptoms that indicate lower-diencephalic or midbrain dysfunction.

Brain Diseases↗
PubMed1988

Orthopaedic management of bony metastases of renal cancer.

Pain and loss of function of the skeleton are the main symptoms of patients with bony metastases of renal cancer. Experience with 57 patients (40 of them had 52 operations) shows the surgical possibilities for early restoration of function and pain relief. Metastases were mainly localized in the femur, vertebral column, and humerus. Surgical management after nephrectomy consisted either in curettage and stabilization with plates and bone cement in case of multiple metastases or in resection and endoprosthetic treatment for solitary lesions. Thus the quality of life could be improved in every case. Survival time and primary diagnosis of hypernephroma prior to the detection of bony metastases are closely related.

Adult↗
PubMed1987

Involvement of chromosome X in primary cytogenetic change in human neoplasia: nonrandom translocation in synovial sarcoma.

A translocation that involves chromosome X (band p11.2) and chromosome 18 (band q11.2) was observed in short-term in vitro cultures of cells from five synovial sarcomas and one malignant fibrous histiocytoma. In four of these tumors, the translocation t(X;18)(p11.2;q11.2) was reciprocal. The two other tumors had complex translocations: t(X;18;21)(p11.2;q11.2;p13) and t(X;15;18)(p11.2;q23;q11.2). A translocation between chromosomes X and 18 was not detected in other histological types of soft tissue sarcoma. The X;18 rearrangement appears to characterize the synovial sarcoma and is the first description of a primary, nonrandom change in the sex chromosome of a human solid tumor.

Adolescent↗
PubMed1986

Membrane tolerance to ethanol is rapidly lost after withdrawal: a model for studies of membrane adaptation.

The structural properties of liver microsomes and erythrocytes obtained from rats that had been chronically administered ethanol were examined by electron spin resonance (ESR) following ethanol withdrawal for 1-10 days. Membranes obtained from control animals exhibited considerable molecular disordering upon the addition of ethanol in vitro (50-100 mM). Conversely, microsomal and erythrocyte membranes from alcoholic animals were resistant to this disordering by ethanol (membrane tolerance). These membrane properties were also apparent in lipid bilayers comprised of either total lipids or phospholipids isolated from the control and alcoholic animals. While several weeks of ethanol administration were required for both erythrocytes and microsomes to develop membrane tolerance, erythrocytes from alcoholic animals were disordered by ethanol in vitro after the animals had been withdrawn from ethanol for only 1 day. The same rapid loss of tolerance was observed in microsomes after 2 days of withdrawal. The same time course for the loss of tolerance was observed in lipid bilayers prepared from the total lipid and phospholipid extracts. No significant differences in the cholesterol/phospholipid ratio were observed between the microsomal or erythrocyte membranes isolated before and after withdrawal. Thus, alterations in the microsomal and erythrocyte phospholipids, and not cholesterol content, were responsible for conveying membrane tolerance. Membrane structural properties can be rapidly adjusted in a mammalian system in response to the withdrawal of the external membrane perturbant ethanol. The withdrawal model, which begins with established membrane tolerance and leads to rapid and complete loss of tolerance, provides a model to analyze the compositional changes responsible for this tolerance to disordering by ethanol.

Adaptation, Physiological↗
PubMed1986

Phosphatidylinositol from ethanol-fed rats confers membrane tolerance to ethanol.

The presence of ethanol disorders (fluidizes) biological membranes, but its chronic administration confers resistance to this perturbation (membrane tolerance). The latter effect has been invoked as an explanation for behavioral tolerance in alcoholics, but the molecular basis for membrane tolerance is obscure. To study the molecular mechanisms of this acquired resistance to disordering, we fed rats ethanol (36% of total calories) for 35 days, after which we quantitatively separated the phospholipids of hepatic microsomal membranes by high-performance liquid chromatography. Multilamellar vesicles were prepared from the recombined phospholipid classes, and their physical properties were examined by electron spin resonance. Vesicles composed of phospholipids from untreated rats were disordered (fluidized) in the presence of ethanol, whereas those made from phospholipids of ethanol-fed rats were resistant to this effect. When phosphatidylcholine (66.5 mol %), phosphatidylethanolamine (21 mol %), or phosphatidylserine (4.0 mol %) from ethanol-fed rats replaced their corresponding phospholipids in vesicles prepared from microsomal phospholipids from untreated rats, the membranes were still disordered by ethanol. In contrast, when 2.5-8.5 mol % phosphatidylinositol from ethanol-fed rats replaced phosphatidylinositol from untreated rats, the reconstituted membranes were rendered resistant to ethanol-induced disordering. Liver microsomal phosphatidylinositol (2.5-8.5 mol %) from ethanol-fed rats also conferred membrane tolerance to vesicles composed of bovine liver and brain phospholipids, an effect which demonstrates that the ability of phosphatidylinositol to confer membrane tolerance is not restricted to the microsomal membrane.

Alcoholism↗
PubMed1986

Arachnoid cysts of the posterior fossa.

Arachnoid cysts of the posterior fossa are an uncommon clinical entity. The two cases presented in this review were evaluated without vertebral angiography. We think that the development of magnetic resonance imaging may obviate the need for angiography in selected cases.

Adult↗
PubMed1986

Computerized tomography, magnetic resonance imaging, and positron emission tomography in the study of brain trauma. Preliminary observations.

Results of computerized tomography (CT), magnetic resonance imaging (MRI), positron emission tomography (PET), xenon-133 measurement of cerebral blood flow (CBF), and neuropsychological assessments are described in three head-injured patients. The patients were selected because they presented with intracranial hemorrhage diagnosed by CT. Two of the patients were studied acutely and again approximately 6 months later. In the acute stage, MRI was superior to CT in identifying the precise location and extent of intracranial hemorrhage and associated edema. Small subdural hematomas diagnosed on MRI were missed with CT scanning. The extent of apparent encephalomalacia in the chronic stages of injury was also better defined with MRI. Positron emission tomography showed disturbances of glucose metabolism that extended beyond the structural abnormalities demonstrated by MRI and CT; anterior temporal lobe dysfunction was particularly evident in all three patients. Regional CBF studies failed to detect a number of the abnormalities seen on MRI and CT, and even ignored the metabolic dysfunction evident on PET that should have been accompanied by changes in regional CBF. The neuropsychological studies localized frontal lesions, but did not reveal abnormalities attributable to the structural lesions and the reduced metabolism in the anterior temporal lobes.

Adult↗
PubMed1985

Nuclear magnetic resonance: an overview of its spectroscopic and imaging applications in pediatric patients.

Magnetic resonance (MR) is a technique that permits the noninvasive evaluation of morphologic features and function based on the distribution of protons and other selected elements. We present a basic description of MR and illustrate both 31P-MR spectroscopy and proton imaging applications in pediatric patients. The applications of these techniques are diverse, and are presented concisely in an attempt to give pediatricians an overview of this new technology and its potential role in patient management.

Adolescent↗
PubMed1985

Neurological manifestations in abused children who have been shaken.

Four infants with the 'shaken infant syndrome' are described. None had skull fractures and only one had a subdural hematoma. All had extensive retinal and pre-retinal hemorrhages. Follow-up computerized tomography showed severe brain atrophy, multiple hypodense areas and ventricular enlargement. Three of the patients suffered severe, permanent brain damage, with mental retardation, spasticity and blindness. It is suggested that the underlying pathogenesis of this syndrome is acutely increased intrathoracic pressure, transmitted into the head to cause multiple venous infarctions. Retinal and pre-retinal hemorrhages are cardinal features of this syndrome and their presence should raise the suspicion of this form of battering in the absence of the 'classical' signs of battering.

Battered Child Syndrome↗
PubMed1985

Measures of the sentence intonation of read and spontaneous speech in American English.

The visual abstraction procedure used in previous studies of declination was tested using 12 subjects who each fit the F0 contours of 19 spoken short simple sentences with baselines. These baselines were found to be poorly replicated the fitters. An objective all-points least-squares best-fit procedure was tested on this corpus and on a set of sentences that had been produced in both spontaneous and read speech by six speakers. The all-points linear regression line was a better descriptor of the F0 contours than either baselines or toplines. Declination did not always occur in these simple declarative sentences; there was more variation present in the F0 contours of sentences that had been uttered during spontaneous speech; 35% of the spontaneous sentences did not show declination; 45% of these sentences better fit the breath-group model. Their F0 contours could be described by a level all-points linear regression line followed by a falling terminal segment.

Adult↗
PubMed1984

Active oxygen acts as a promoter of transformation in mouse embryo C3H/10T1/2/C18 fibroblasts.

There is much evidence from in vivo and in vitro carcinogenesis studies that active oxygen species play a role in tumor promotion. We tested directly whether superoxide produced extracellularly by xanthine-xanthine oxidase (X-XO) has the capacity to promote initiated mouse embryo C3H/10T1/2 fibroblasts. Cell cultures initiated with either 137Cs gamma-rays or benzo[a]pyrene diol epoxide I were found to transform 3-30 times more effectively when subsequently treated daily for 3 weeks with nontoxic doses of X-XO. Scavengers of active oxygen radicals such as superoxide dismutase or superoxide dismutase in combination with catalase reduced the frequency of appearance of transformed foci by 3-25 times when compared to cultures receiving X-XO alone. These results show that active oxygen species such as superoxide and H2O2 can act in a promotional manner that mimics the effects of the mouse skin promoter phorbol 12-myristate 13-acetate in this system. X-XO also acted as a weak complete carcinogen.

7,8-Dihydro-7,8-dihydroxybenzo(a)pyrene 9,10-oxide↗
PubMed1983

Therapeutic and clinical course of deep vein thrombosis.

We have reviewed our experience with the treatment of 250 patients with deep vein thrombosis diagnosed by contrast venography. The level of thrombosis was recorded according to the anatomic level to which it extended. A third of the patients had cancer, and the most common clinical findings were swelling and pain. The risk of the development of pulmonary embolism, based on the anatomic level of initial deep vein thrombosis, revealed the following: 12 of 115 patients (10 percent) with level I (calf) deep vein thrombosis developed pulmonary embolism, as did 2 of 27 patients (7 percent) with level II (popliteal) disease, 5 of 60 (8 percent) with level III (thigh) disease, 1 of 19 patients (5 percent) with level IV (groin) disease, and 2 of 26 patients (8 percent) with level V (iliac) disease. Based on our favorable experience with heparin we believe that heparin is the treatment of choice for deep vein thrombosis regardless of the anatomic level. The incidence of pulmonary embolism does not appear to be influenced significantly by the level of the deep vein thrombosis.

Adolescent↗
PubMed1983

Soft-tissue sarcomas of the head and neck in children.

Thirty-two children aged three months to 17 years (median six years) were diagnosed with soft-tissue sarcoma of the head and neck and treated at the Children's Hospital of Philadelphia and the Hospital of the University of Pennsylvania from 1971 to 1981. Thirty-one received chemotherapy and all received radiation therapy (RT). Twenty-five patients had pre-treatment computed tomography (CT) scans, which were used for staging and treatment planning. Doses of radiation therapy ranged from 3000 to 7300 rad to the primary tumor (median 5000 rad). The overall five-year survival of the entire group of 32 patients was 75%. Ten of the 32 patients had invasive cranial parameningeal disease as demonstrated by bony erosion at the skull base, seen on CT in eight and plain radiographs in two patients. Eight of these 10 patients have developed recurrent sarcoma: four in the meninges, two locally, one regionally and one distantly. Five of these 10 children with invasive cranial parameningeal sarcoma received 3000 rad of prophylactic cranial irradiation, begun within the first 12 days of chemotherapy, and none developed meningeal disease. In contrast, only one of the 22 patients without invasive cranial parameningeal disease has relapsed (local recurrence). The data suggest that soft-tissue sarcomas of the head and neck in children without invasion into the base of the skull (invasive cranial parameningeal disease) are usually cured. CT scans are essential for staging. Patients with invasion of the base of the skull may be protected from meningeal relapse by early cranial irradiation, although they still are at high risk for relapse in other sites.

Adolescent↗
PubMed1983

[Basilar thrombosis--an example of comprehensive rehabilitation of a 26-year-old female patient].

Medical elimination/reduction of a more or less acute functional disorder may be something considerably different from restoration to good health, or the ability to lead an independent life. The form this discrepancy may take; what it can mean to the patient, not least in terms of time consumed; which possibilities there are in view of a new beginning, a re-orientation; which ways and means there exist on the part of the patient as on that of the therapeutic personnel involved, or in the light of the legislative provisions; which role is played by society through the employer; how difficult it is to give a prognosis; these are the issues the authors intend to illustrate by describing the rehabilitation process a young woman of 26 years of age underwent following successful re-canalization of a previously thrombosed basilar artery by urokinetic fibrinolysis. It is also underlined that any rehabilitative measure taken should be oriented towards attainable goals, and be based on consultation (but not necessarily general agreement) among the rehabilitative team. This approach will help the patient comprehend the purpose of the measures taken, and serve to prevent hard feelings that may develop.

Adult↗
PubMed1982

Urinary CEA for prediction of survival time and recurrence in bladder cancer.

The prognostic information from carcinoembryonic antigen was evaluated in bacteria-free urines of patients with bladder carcinoma. Patients with elevated (greater than or equal to 30 ng/ml) U-CEA had a poorer relative and symptom-free survival than patients with initial U-CEA below 30 ng/ml. Patients in whom U-CEA decreased from before to after radiation treatment had a better survival rate than patients with increasing U-CEA. These findings were most significant in cases with large (T3 + T4) tumors or with tumors of a lower differentiation (G3). U-CEA appeared to be an independent variable for prognostic evaluation of survival, since these differences were also true within the subgroups of known variables such as classes or grades. All but one of the patients, in whom short-term local control was obtained, had a posttreatment U-CEA below 50 ng/ml. In oncology units, where the more malignant bladder tumors are treated, U-CEA determinations may indicate which patients require intensified monitoring or treatment.

Adult↗