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Biomedical subjects

J Miller

Publications and source records attributed to J Miller.

At least 901 records · Page 50Linked to original sources
PubMed1985

Outpatient computer-based 32-hour esophageal pH studies teletransmitted to a central esophageal laboratory.

Using a computer-based 32-hour esophageal pH system with a small patient-worn digital recording computer, outpatient studies are performed in the physiologic environment of the patient's workplace and home. Samples are taken at 15-s intervals, and the pH data stored in this computer are then fed into the main computer in the Central Esophageal Laboratory for analysis, scoring, printing out, and storage. Satellite esophageal laboratories located in regional hospitals, clinics, and physicians' offices conduct pH studies by telecommunication, using antimony electrodes, a recording computer, and a modem to transmit data to the main computer for high-quality computer analysis. One main computer and associated personnel serve multiple satellite stations. This maintains patient-physician relationships and is highly cost-effective.

Computers↗
PubMed1984

Accuracy of chest computerized tomography in detecting malignant hilar and mediastinal involvement by squamous cell carcinoma of the lung.

The accuracy of chest computerized tomography (CT) in detecting malignant hilar and mediastinal involvement by squamous cell carcinoma of the lung is examined. The preoperative chest CT scans of 74 patients with pathologically proven squamous cell lung carcinoma were prospectively and retrospectively reviewed. Criteria for the diagnosis of malignant hilar involvement were nonvascular mass enlarging the hilum; local alteration of hilar contour; adenopathy greater than 1 cm; thickened posterior wall of the bronchus intermedius and distal upper lobe bronchi; and bronchial displacement, compression, and obstruction. Criteria for the diagnosis of malignant mediastinal involvement were confluence of tumor with the mediastinum, altered contour of the azygoesophageal recess, thickened posterior wall of the proximal main stem bronchi, and mediastinal adenopathy greater than 1 cm. Calcified hilar and mediastinal nodes were considered benign. Our results, corrected for reader error, were 92% sensitive, 92% specific, and 96% accurate in the hilum and 95% sensitive, 77% specific, and 82% accurate in the mediastinum. These data support a significant role for chest CT in the preoperative staging of non small cell lung carcinoma.

Carcinoma, Squamous Cell↗
PubMed1984

Effect of spinal cord lesions on convulsive activity induced by intrathecal morphine.

Non-specific convulsive behavior induced by intrathecal (IT) morphine microinjection appears to be tonically modulated by centrifugal pathways originating within the brain since the frequency of IT morphine-induced hindlimb seizures and myoclonic twitches are both increased following spinal transection. These effects on convulsant activity are dissociable by selective neural lesions. Bilateral dorsolateral funiculus lesions potentiate seizure activity whereas ventral funiculus lesions and, to a lesser extent, interruption of cerebral cortical influences enhance myoclonic twitch activity. These initial studies indicate that distinct supraspinal centers differentially modulate myoclonic and seizure activity and suggest that an understanding of these systems may have clinical implications for the control of convulsant activity.

Animals↗
PubMed1984

Purification of creatine kinase-BB isoenzymes from human and canine tissues.

We describe a procedure for the purification of creatine kinase BB isoenzyme from canine and human brain tissue. The purification involves sequentially 50-70% (NH4)2SO4 fractionation, DEAE-Sephacel, Blue-Sepharose CL-6B, and chromatofocusing chromatography. This method produces a homogeneous protein purification as verified by sodium dodecylsulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and isoelectric focusing chromatography.

Animals↗
PubMed1984

Serotonergic stimulation of pituitary-adrenocortical activity in rats: evidence for multiple sites of action.

5-Hydroxytryptophan (5-HTP) elevated serum corticosterone concentrations when administered either intraperitoneally (i.p.) or intraventricularly. Inhibition of aromatic L-amino acid decarboxylase outside of the blood-brain barrier antagonized the corticosterone response, but only when the 5-HTP was given i.p. Stimulation of the pituitary-adrenocortical system by fenfluramine was not affected by 5,7-dihydroxytryptamine pretreatment, whereas the stimulation produced by quipazine administration was blocked by lesions of the basomedial hypothalamus. These results suggest that serotonergic drugs can act at multiple sites (i.e., both central and peripheral) to evoke a pituitary-adrenocortical response.

5-Hydroxytryptophan↗
PubMed1984

Cataleptic effects of opiates following intrathecal administration.

Intrathecal (i.t.) administration of D-ala2-methionine-enkephalinamide (DALA) and methadone induces pronounced hindlimb catalepsy in rats. DALA is more potent than methadone in inducing this behavior and catalepsy induced by both compounds is partially blocked by prior treatment with naltrexone. Intrathecal morphine induces convulsive hindlimb activity at doses of 25, 100 and 400 micrograms. However, only the highest dose produces indications of cataleptic behavior. It is suggested that whereas the convulsive behavior induced by i.t. morphine is not mediated by specific opiate receptors, catalepsy induced by all 3 compounds is.

Animals↗
PubMed1984

Nonspecific convulsions are induced by morphine but not D-Ala2-methionine-enkephalinamide at cortical sites.

Cortical application of morphine (25, 100 and 400 micrograms) induced cortical spikes in a dose-related fashion and, at 400 micrograms, behavioral and electrographic seizures. These electrographic seizures were not opiate specific since this activity occurred undiminished in naltrexone-pretreated animals and was even potentiated in animals pretreated for 6 days with increasingly higher doses of systemic morphine. In contrast to the effects induced by morphine, the most consistent electrographic effect of cortically applied D-Ala2-methionine-enkephalin (DALA) and methadone was a depression of cortical EEG. These results support the hypothesis that the cortex and spinal cord together form the anatomical substrate of the documented nonspecific convulsive action of high systemically administered doses of morphine.

Animals↗
PubMed1984

Pachyonychia congenita. Electron microscopic and epidermal glycoprotein assessment before and during isotretinoin treatment.

Two patients, a father and son, with pachyonychia congenita were treated with orally administered isotretinoin because the extreme deformity and discomfort associated with their massive keratoderma interfered with their work and school, respectively. While clinical benefits could not be sustained, electron microscopic findings compatible with suppression of abnormal keratinization were observed. In addition, skin biopsy samples were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and the gels were then subjected to a lectin overlay technique with concanavalin A labeled with iodine 125. The distribution of specific glycoproteins was found to be different for lesional as against normal epidermis. The procedure was repeated after oral treatment with isotretinoin. The labeled glycoprotein pattern of the lesional epidermis was clearly distinguishable from both the pretreatment lesional and the normal epidermis; it was mostly intermediate between the two. The normal epidermis was virtually unaffected by the retinoid treatment.

Adult↗
PubMed1984

Massive hematuria following percutaneous biopsy of renal allograft. Successful control by selective embolization.

We report on a patient who underwent a percutaneous needle biopsy of a renal allograft for evaluation of compromised function. Gross hematuria occurred immediately and persisted for three weeks, interrupted only by long intervals of anuria due to obstruction by a clot. The bleeding was controlled successfully by selective transcatheter embolization with a coli and an absorbable gelatin sponge (Gelfoam). The techniques and complications of allograft biopsy procedures are reviewed, and the management of hematuria occurring after a percutaneous needle biopsy is discussed. A percutaneous needle biopsy is the preferred method of sampling the transplanted kidney, with an adequate specimen obtained in 96% of cases. Hematuria, that has been reported to complicate 7% of percutaneous biopsy procedures, is usually transient, and only rarely is intervention required. Angiographically directed selective embolization is an effective technique for controlling massive or prolonged urinary hemorrhage after renal allograft biopsy.

Adolescent↗
PubMed1984

Characteristics of a human epidermal squamous carcinoma cell line at different extracellular calcium concentrations.

A continuous line derived from a human skin squamous cell carcinoma has been grown in media of high, normal and low Ca2+ concentrations. The growth rate was unaffected by the Ca2+ levels even though morphological changes were observed. Desmosomes were absent at low Ca2+ and areas of cell piling were observed at high Ca2+. Cell protein staining patterns on polyacrylamide gels were identical for cells grown at the three Ca2+ levels. The variations were minor for the glycoproteins reacted with 125I-conA. Lactoperoxidase iodination revealed changes in cell surface proteins, most markedly in the emergence of new proteins at high Ca2+.

Calcium↗
PubMed1984

Plasmodium falciparum: thiol status and growth in normal and glucose-6-phosphate dehydrogenase deficient human erythrocytes.

Thiol status and growth in normal and glucose-6-phosphate dehydrogenase-deficient human erythrocytes. Experimental Parasitology 57, 239-247. The relationship of the thiol status of the human erythrocyte to the in vitro growth of Plasmodium falciparum in normal and in glucose-6-phosphate dehydrogenase (G6PD)-deficient red cells was investigated. Pretreatment with the thiol-oxidizing agent diamide led to inhibition of growth of P. falciparum in G6PD-deficient cells, but did not affect parasite growth in normal cells. Diamide-treated normal erythrocytes quickly regenerated intracellular glutathione (GSH) and regained normal membrane thiol status, whereas G6PD-deficient cells did not. Parasite invasion and intracellular development were affected under conditions in which intracellular GSH was oxidized to glutathione disulfide and membrane intrachain and interchain disulfides were produced. An altered thiol status in the G6PD-deficient erythrocytes could underlie the selective advantage of G6PD deficiency in the presence of malaria.

Diamide↗
PubMed1984

Effects of psychoactive drugs on plasma catecholamines during stress in rats.

In unstressed rats, morphine, pentobarbital, diazepam and alprazolam were without effect on plasma norepinephrine (NE) and epinephrine (E) levels. Amphetamine increased the levels of both catecholamines. In stressed rats, morphine did not affect the stress-induced increases in NE and E. Amphetamine enhanced the catecholamine stress-response further. Diazepam reduced stress-induced increases of NE levels. Pentobarbital and alprazolam attenuated stress-induced increases of both NE and E levels; this effect was particularly marked with alprazolam.

Alprazolam↗
PubMed1984

The precordial thump.

The American Heart Association (AHA) currently recommends the precordial thump as the initial maneuver in treatment of ventricular tachycardia (VT) and monitored ventricular fibrillation (VF). These recommendations are based largely on anecdotal reports of successful "thump-version" of asystole, VF, and VT. The Milwaukee County Paramedic System follows the AHA guidelines in the treatment of VT and VF. The precordial thump is included in the advanced cardiac life support (ACLS) paramedic training program, and has been used in our approach to the pulseless, nonbreathing patient. During an eight-month period, 50 pulseless, nonbreathing patients received precordial thumps during ACLS resuscitative attempts. Twenty-seven patients who developed monitored VT and 23 patients with monitored VF were thumped. Three of 27 patients (11%) with VT were thumped into a supraventricular rhythm, 12 of 27 patients (44%) remained in VT, and 12 of 27 patients were thumped from VT into more malignant rhythms: three, into asystole; eight, into VF; and one, into an idioventricular/electromechanical dissociation rhythm. A total of 23 patients were thumped without effect. Subsequently, using countershock and medications, 12 of these 23 patients were successfully resuscitated. In the prehospital setting the precordial thump is usually not beneficial, and may be detrimental. Thus its use as the initial maneuver in treating the cardiac arrest patient with VT or VF in this setting cannot be supported. The presence of acidosis and hypoxia may explain why prehospital precordial thump responses differ from those seen in the hospital environment.

Adult↗
PubMed1984

Malpractice in the emergency department--review of 200 cases.

Two hundred consecutive cases brought to the attention of a malpractice insurer by evidence of expected legal action were reviewed. Of these cases, 132 (66%) were attributed primarily to misdiagnosis, and 87 of these would have satisfied admission criteria. The most common error was grossly deficient examination relating to the chief complaint. Focused attention to physical examination and diagnostic skills, history taking, and minimal use of laboratory studies could have avoided the initiation of the majority of cases.

Diagnostic Errors↗
PubMed1984

Response to aminoglutethimide and cortisone acetate in advanced prostatic cancer.

Forty patients with metastatic adenocarcinoma of the prostate were evaluated for response to treatment with aminoglutethimide plus cortisone acetate. All had relapsed from or failed to respond to primary endocrine treatment with orchidectomy or stilboestrol. Nineteen patients (48%) showed subjective response, in most cases relief of bone pain. Side effects limited treatment in only 3 patients. We conclude that aminoglutethimide plus cortisone acetate is a useful addition to the treatment available for this difficult group of patients. The mechanism by which this treatment has a beneficial effect remains unclear.

Adenocarcinoma↗
PubMed1984

Simian virus 40 T antigen is required for viral excision from chromosomes.

We describe experiments that show that simian virus 40 (SV40) T antigen is required for viral excision from host chromosomes at some point prior to or during the homologous recombination events that create circular wild-type virus. Two recombinant SV40-pBR322 plasmids were constructed such that homologous recombination across similar-sized but different duplications of SV40 would reconstitute wild-type viral DNA. One plasmid (pSVED) was constructed such that the duplication separates the viral early T-antigen promoter from the coding sequences; the other recombinant (pSVLD) contains a duplication of the late viral sequences and thus maintains a complete T-antigen gene. These plasmids were individually established in Rat 2 cells via cotransformation with the herpes virus Tk gene. Both classes of cell lines contained integrated tandem arrays of the plasmids and yielded equivalent levels of infectious virus after cell fusions with COS-7 cells; however, only the T+ lines yielded virus after cell fusion with CV-1 cells. These results are consistent with the notion that viral excision is initiated by T-antigen-mediated in situ replication of viral DNA as proposed in the "onion skin" model. In contrast, both plasmids yielded infectious virus when transiently introduced via transfection into CV-1 cells. This latter finding is discussed in terms of the possible induction of cellular repair and recombination pathways evoked by the introduction of damaged DNA into the nucleus.

Animals↗