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Biomedical subjects

J L Potter

Publications and source records attributed to J L Potter.

At least 37 records · Page 2Linked to original sources
PubMed1983

Occult hepatic sinusoid tumor of infancy simulating neuroblastoma.

Two infants with hepatosplenomegaly and an occult tumor of hepatic sinusoids are reported. Although secretion of biogenic amines of neuroblastoma was not elevated, infrequent neurosecretory granules were observed by electron microscopy in the cytoplasmic processes of the tumor cells. The infants responded to vincristine and prednisone therapy and are tumor free 8 and 2 years later, respectively. The clinical, radiographic, biochemical, and microscopic findings of these cases are presented. The distinction from other infantile hepatic sinusoid small round cell tumors is based on the light and electron microscopic findings. This neuroepithelial tumor is either an unusual form of neuroblastoma or a neoplasm of APUD cell origin. If chemotherapy is utilized, it should be selective and limited.

Drug Therapy, Combination↗
PubMed1983

Neonatal hepatic malignant tumor. A correlative imaging approach.

We report the hepatobiliary study of a neonate with hepatomegaly. Biliary atresia was ruled out. Fortuitous demonstration of massive parenchymal lesions redirected the clinical management of the child. Other imaging modalities were employed to define further the nature of the lesions. Pediatric reports of non-biliary lesions demonstrated by hepatobiliary scintigraphy are uncommon. To our knowledge, the present case of multiple hepatoblastomas discovered by hepatobiliary imaging is the first report in the literature.

Carcinoma, Hepatocellular↗
PubMed1983

Assessment of follicular development by ultrasonography and total serum estrogen in human menopausal gonadotropin-stimulated cycles.

Ovarian follicular development was assessed by serial ultrasonography in infertile women being treated with human menopausal gonadotropin. Both follicular size and number of follicles correlated with serum estrogen values in most patients, and follicles increased in size 2--3 mm per day. Most patients had serum estrogen values greater than 750 pg/ml when one or more follicles larger than 18 mm were present. A comparison of conception cycles with non-conception cycles did not reveal a significant difference in size or number of follicles, or in the rate of rise or peak value of serum estrogen. When women monitored with ultrasonography were compared with patients treated with gonadotropins prior to the availability of ultrasonography, there was no significant difference in the rates of successful conception, although the number of ampules of pergonal used by the former was significantly reduced, permitting more efficient use of an expensive medication.

Estrogens↗
PubMed1982

Computed tomography in the diagnosis of deep-neck infections.

Computed tomography (CT) of the neck was used to identify deep-neck abscess formation. Twenty-two patients were screened by CT for deep-neck abscesses. Each patient suspected of having a deep-neck infection underwent CT, often with enhancement if the differential diagnosis included the possibility of a tumor or vascular lesion. Six cases were identified, and these patients were taken to surgery for incision and drainage. There were no false-positives or false-negatives in the series. In all six cases of abscesses, the CT scan accurately identified the anatomical location of the abscess, allowing a more accurate planning of the surgical approach. The selective use of CT when deep-neck infections are suspected seems to produce an accurate diagnosis of the presence of an abscess, its location, and the involvement of important surrounding structures.

Abscess↗
PubMed1982

Advantages and limitations of computed tomography scans for treatment planning of lung cancer.

Forty-five Chest computed tomography (CT) scans performed on patients with lung carcinoma (LC) were evaluated in an attempt to understand the pattern of intrathoracic tumor spread and the advantages and limitations this technique offers for treatment planning when compared to planning done by conventional X rays. The following findings can help treatment planning. (1) When regular X rays do not show tumor location (i.e., hemithorax opacification), CT scan will show it in 68% of patients. If regular X rays show a well localized mass, unsuspected tumor extensions were disclosed in 78% of these patients. Hence, CT scans should be done in all LC patients prior to treatment planning; (2) Mediastinal masses frequently spread anteriorly toward the sternum and posteriorly around the vertebral bodies toward the cord and costal pleura. This should be considered for radiotherapy boost techniques; (3) Lung masses spread in one third of cases toward the lateral costal pleura. Thus, the usual 1-2cm of safety margin around the LC are not sufficient in some cases; (4) Tumor size can appear much smaller in regular X rays than in CT scans. Hence, CT scans are necessary for accurate staging and evaluation of tumor response. Some CT scan limitations are: (1) Atelectasis blends with tumor in approximately half of the patients, thus obscuring tumor boundaries; (2) CT numbers and contrast enhancement did not help to differentiate between these two structures; and (3) Limited definition of CT scan prevents investigation of suspected microscopic spread around tumor masses.

Humans↗
PubMed1982

Evaluation of computed tomography numbers for treatment planning of lung cancer.

Computerized tomography numbers (CTN) were evaluated in 32 computerized tomography scans performed on patients with carcinoma of the lung, with the aim of evaluating CTN in normal (lung, blood, muscle, etc) and pathologic tissues (tumor, atelectasis, effusion, post-radiation fibrosis). Our main findings are: 1. Large individual CTN variations are encountered in both normal and pathologic tissues, above and below mean values. Hence, absolute numbers are meaningless. Measurements of any abnormal intrathoracic structure should be compared in relation to normal tissue CTN values in the same scan. 2. Tumor and complete atelectasis have CTN basically similar to soft tissue. Hence, these numbers are not useful for differential diagnosis. 3. Effusions usually have lower CTN and can be distinguished from previous situations. 4. Dosimetry based on uniform lung density assumptions (i.e., 300 mg/cm3) might produce substantial dose errors as lung CTN exhibit very large variations indicating densities well above and below this value. 5. Preliminary information indicates that partial atelectasis and incipient post-radiation fibrosis can have very low CTN. Hence, they can be differentiated from solid tumors in certain cases, and help in differential diagnosis of post radiation recurrence within the radiotherapy field versus fibrosis.

Humans↗
PubMed1982

NMR relaxation of protons in tissues and other macromolecular water solutions.

Nuclear magnetic resonance (NMR) longitudinal (T1) and transverse (T2) relaxation parameters have been evaluated for protein solutions, cellular suspensions and tissues using both data from our laboratory and the extensive literature. It is found that this data can be generalized and explained in terms of three water phases: free water, hydration water, and crystalline water. The proposed model which we refer to as the FPD model differs from similar models in that it assumes that free and hydration water are two phases with distinct relaxation times but that T1 = T2 in each phase. In addition there is a single correlation time for each rather than a distribution as assumed in most other models. Longitudinal decay is predicted to be single exponent in character resulting from a fast exchange between the free and hydration compartments. Transverse decay is predicted to be multiphasic with crystalline (T2 approximately 10 microseconds), hydration (T2 approximately 10 msec) and free (T2 approximately 100 msec) water normally visible. The observed or effective transverse relaxation times for both the hydration and free water phases are greatly affected by the crystalline phase and are much shorter than the inherent relaxation times.

Animals↗
PubMed1982

The neuropathology of glycine encephalopathy: a report of five cases with immunohistochemical and ultrastructural observations.

We studied the spongy myelinopathy of glycine encephalopathy in five patients by using specific antisera. The walls of the vacuoles were stained with the myelin basic protein but not with the myelin associated glycoprotein or the glial fibrillary acidic protein immunostains. The pattern suggested that the vacuoles originated in compact myelin and not from the adaxonal portion of the sheath or from glial processes. Ultrastructural study revealed myelin vacuoles resulting from intraperiod splitting, and there were unusual intranuclear and cytoplasmic inclusions in skeletal muscle in two cases. In addition to the action of glycine as an inhibitory neurotransmitter, structural alterations of myelin may be important in the pathogenesis of the neurologic disorder of glycine encephalopathy.

Amino Acid Metabolism, Inborn Errors↗
PubMed1981

Acute zinc chloride ingestion in a young child.

This brief report describes the clinical course and management of a child who ingested a zinc chloride solution used in a lead soldering process. Injury was limited to bleeding from esophageal erosions and hematemesis. No adverse systemic effects were observed, although serum zinc levels were markedly elevated. A single small dosage of calcium disodium edetate (150 mg dissolved in 75 ml 1:5 normal saline) was effective in normalizing the serum zinc level.

Acute Disease↗
PubMed1981

Elevated GGTP/SGOT ratio. An early indicator of infantile obstructive cholangiopathy.

Early surgical intervention in cases of extrahepatic biliary atresia improves prognosis. The ratio of serum gamma-glutamyl transpeptidase to SGOT is elevated in infants with infantile obstructive cholangiopathy. This appears to be a sensitive method for distinguishing infants with extrahepatic biliary atresis from those with neonatal hepatitis. This distinction was evident as early as 5 to 14 days of age and was clearly manifest in ten of 12 infants with biliary atresia. The ratio was also elevated in patients with alpha 1-antitrypsin deficiency who had bile duct proliferation. We do not claim that the ratio can clearly distinguish extrahepatic biliary atresia from neonatal hepatitis, but we do suggest that an elevation raises a strong presumption of biliary obstruction and invites early consideration of laparotomy and examination of the biliary tree.

Aspartate Aminotransferases↗
PubMed1981

Screening for the Tay-Sachs carrier: a compromise program.

A modified program designed to screen for the Tay-Sachs carrier is presented in which testing is limited to one or both partners, as needed, in an Ashkenazi Jewish (Jews of central and eastern Europe ancestry) mating when there is a definite commitment toward having a child, or in the early stages of the pregnancy. Testing of unmarried individuals is discouraged. The approach maximizes individualization of both the medical and laboratory aspects of the program and promotes a positive and beneficial relationship between physician and clinical chemist. There is little involvement of the lay population or clergy, and no special sources of funding are required. Whereas most mass screening programs for the Tay-Sachs carrier have attempted to educate large numbers of the lay public to bring pressure upon the medical community, we have reversed this approach and taken the much easier course of educating small numbers of physicians to better care for their patients. The program has been used successfully in a moderate-size city in which communication lines between laboratory and physician are easily established.

Communication↗
PubMed1980

Apparent normal leukocyte acid maltase activity in glycogen storage disease type II (Pompe's disease).

We present a case of glycogen storage disease type II (Pompe's disease) with the classical clinical presentation and characteristic electrocardiographic changes of this disorder. An acid maltase (EC 3.2.1.20) determination in the peripheral leukocytes revealed normal activity; however, acid maltase activity was completely absent in a pre-mortem skeletal muscle biopsy. Post-mortem studies showed acid maltase activity to be absent in all tissues examined, including cultured skin fibroblasts. Massive glycogen deposition corresponded to the localization of the enzymic deficiency, except in the brain, where glycogen content was within the normal range. The acid maltase activity in mixed peripheral leukocytes was due to an isoenzyme of acid maltase in the granulocyte series. Antenatal diagnosis was accurate in a subsequent pregnancy, but discordance between enzyme activity in different cell lines in an individual with a genetic disease is a conceivable source of error in both prenatal and postnatal diagnoses.

Female↗