Transectional echo planar imaging of the heart in cyanotic congenital heart disease

Echo planar imaging is that form of magnetic resonance imaging which gives very short image acquisition times. The method has been used to produce images of the infant heart which are free of cardiorespiratory motion artefact, despite tachypnoea and tachycardia. EPI transections of the normal heart are compared with transections in truncus arteriosus, tetralogy of Fallot, right heart hypoplasia and transposition of the great arteries. The diagnosis of the cause of cyanosis in these infants was established by the noninvasive EPI method and validation of the findings may be found in transectional postmortem analyses reported in the literature.

Echo planar imaging of normal and abnormal connections of the heart and great arteries

Echo planar imaging (EPI) is that form of magnetic resonance imaging which provides very short image acquisition times. EPI also provides very rapid sequential imaging. The EPI method is ideal for imaging the heart and thoracic content because images are devoid of cardio-respiratory motion artefact. Previously an analysis of transectional images has been presented. This paper is concerned with the study of the heart by the use of EPI constructions in the sagittal and coronal planes. Defining connections between ventricle and great artery is of cardinal importance in paediatric cardiology. EPI constructions in the normal heart, transposition, truncus arteriosus and right heart hypoplasia are presented and discussed.

Results of a screening method used in a 12-month stool survey for Escherichia coli O157:H7

Escherichia coli serotype O157:H7 has been epidemiologically linked to outbreaks of hemorrhagic colitis associated with fast-food restaurants and nursing homes. Sporadic cases now exceed those associated with outbreaks. The incidence of the organism in patients with common diarrhea syndromes and in asymptomatic persons is unknown. Routine serotyping of E. coli isolates is impractical for most clinical microbiology laboratories. We developed a screening plate by utilizing sorbitol fermentation as a biochemical marker to identify organisms for serotyping. A total of 2,552 stool samples were screened. In 106 (4.1%), sorbitol-negative E. coli were identified. Of these, two were serotype O157:H7, and both produced a Vero cell toxin. One patient had hemorrhagic colitis and the other a mild, febrile, self-limited diarrhea with no other bacterial pathogen identified. This plate provides an easy, effective method of screening for sorbitol-negative E. coli, a process facilitating the selection of organisms for serotyping and one that may help clarify this organism's role in human disease.

Biological activity of recombinant human interleukin-2 produced in Escherichia coli

The gene for interleukin-2 was isolated from the Jurkat cell line and from normal peripheral blood lymphocytes and, when inserted in Escherichia coli, was expressed at high concentrations. This interleukin-2 was purified to apparent homogeneity and tested for biological activity in a variety of assays in vitro and in vivo. The recombinant lymphokine supports the growth of murine and human interleukin-2 dependent cell lines, enhances the generation of murine and human cytolytic cells in vitro, and generates lymphokine activated killer cells from murine and human lymphocytes. It has a serum half-life of 2 to 3 minutes in the mouse and significantly enhances the generation of cytolytic cells in vivo after alloimmunization. No functional differences between native and the recombinant interleukin-2 molecules have been detected.

Real-time nuclear magnetic resonance clinical imaging in paediatrics

Echo-planar imaging (EPI), a distinctive variant of nuclear magnetic resonance, needs only a fraction of a second for an image to be acquired and so is free from movement artifacts caused by respiration or heart beat. Clinical findings in the lungs, heart, and mediastinum of three children with high respiratory and heart rates who were examined by EPI are described.

Dynamic NMR cardiac imaging in a piglet

NMR echo-planar imaging (EPI) has been used in a realtime mode to visualise the thorax of a live piglet. Moving pictures are available on an immediate image display system which demonstrates dynamic cardiac function. Frame rates vary from one per cardiac cycle in a prospective stroboscopic mode with immediate visual output to a maximum of 10 frames per second yielding up to six looks in one piglet heart cycle, but using a visual playback mode. A completely new system has been used to obtain these images, features of which include a probe assembly with 22 cm access and an AP400 array processor for real-time data processing.

Serial casting for the management of spasticity in the head-injured adult

Soft tissue contractures resulting from spasticity are a frequent sequella of traumatic head injuries. This article identifies rationale for the use of serial casting to manage these deformities, provides guidelines for cast fabrication and application, and reports the results of lower extremity casting on 42 head-injured adults at Rancho Los Amigos Hospital.

Prevalence and significance of arrhythmias in long-term survivors of cardiac transplantation

The prevalence and significance of arrhythmias after cardiac transplantation were evaluated in the absence of acute rejection in 13 long-term survivors (greater than 3 months). ECGs were obtained daily for the first 70 days 8- and 24-hour ambulatory electrocardiographic monitoring was performed 3 months after the transplantation and every 6 months thereafter. Junctional rhythm occurred during the early transplant period (less than 70 days) in nine of 13 patients. Complex premature ventricular depolarizations (Lown grade III or higher) were present in the late transplant period (greater than 70 days) in all five patients in whom severe coronary artery disease was found in the donor heart at postmortem, compared with two of the eight remaining patients (six survivors and two patients who died but did not have coronary artery disease at postmortem) (p less than 0.05). The high prevalence of junctional rhythm in the early transplant period appeared to be due to sympathetic denervation and reversible surgical damage to and ischemia of the sinus node region of the donor heart. Routine ambulatory electrocardiographic monitoring detected complex premature ventricular depolarizations, which were a sensitive marker for the subsequent mortality related to accelerated atherosclerosis of chronic rejection in the donor heart.

Effect of vegetarianism on the zinc status of pregnant women

The zinc status of 12 pregnant vegetarian women, six pregnant nonvegetarian women, and five nonpregnant vegetarian women was evaluated. Zinc intake was calculated from 3-day dietary records. Hair, urinary, and nonfasting plasma samples were collected during an interview. Dietary, plasma, urinary, and hair zinc levels did not differ significantly between the pregnant vegetarians and nonvegetarians. But plasma zinc was about 21% lower in the pregnant women than the nonpregnant women even though the pregnant women consumed about twice as much zinc as the nonpregnant women. The data suggest that the parameters of zinc status studied were affected by pregnancy more than ovo-lacto vegetarian dietary habits.

Community organizing lessons for health care consumers

This article analyzes the efforts of health care consumers to organize independently of, but with reference to, the Health Systems Agency in east central Illinois. Beginning with a tactical investigation which disclosed a lack of effective public participation, consumers formed an organization which conducted a series of community forums to provide information and generate publicity about local health care issues, sponsored training workshops for consumer leaders and HSA board members, worked to delay the final designation of the agency, and organized to take control of the local HSA board. They recruited a large number of new HSA members, enlisted provider and consumer candidates to run for the board, conducted a vigorous election campaign, and finally claimed a majority of seats. Among the conclusions drawn are that health care planning cannot be considered apart from a context of politics, and that community organization is important for consumers wishing to exercise power.

Making board meetings work: the Doyle/Straus interaction method

The Doyle/Straus Interaction Method is just now beginning to be used at corporate board meetings on the West Coast. The methodology, based on ten years of experimentation with problem-solving and decisionmaking groups of all kinds, seems to hold a host of benefits not only for meetings at board level but for committee meetings of all kinds. Their step-by-step analysis of the problems that are caused by people and space promises much for the corporations that want to move the directorate into the 20th Century or even the 21st!

Skin porphyrin and photosensitivity in the porphyric rat

Skin porphyrin assays and photobiological studies in normal and porphyric rats suggest that in the latter, skin photosensitivity to 400 nm radiation is associated with raised uroporphyrin and 7-carboxylic porphyrin in the skin.

Prophylaxis and immunization in mice by use of virus-free defective T particles to protect against intracerebral infection by vesicular stomatitis virus

Defective interfering T particles of vesicular stomatitis virus provide remarkable protection against viral disease and death when introduced intracerebrally in large numbers along with an otherwise rapidly fatal low dose of standard infectious virus. This profound prophylactic effect of defective T particles is due to homologous autointerference since it is serotype-specific and interferon is not induced. This protective effect can be demonstrated only with preparations of T particles that have been purified completely free of infectious virions. When pure T particles are injected intracerebrally along with large doses of infectious virus, they convert an otherwise rapidly fatal disease process to a slowly progressing virus infection that generally terminates in death after many days of wasting disease and paralysis. Intracerebral injection of virus-free T particles alone is apparently innocuous to mice and stimulates immunity to massive doses of homologous infectious virus. In vitro, virus-free T particles at extremely high multiplicities depress cellular RNA and protein synthesis and kill BHK21 cells in culture, but do not exhibit such effects at moderately high multiplicities.

Attempts to detect homologous autointerference in vivo with influenza virus and vesicular stomatitis virus

Von Magnus particles of influenza virus and defective interfering T particles of vesicular stomatitis virus were unable to provide significant protection of mice from disease or death when inoculated intranasally or intracerebrally along with moderate or high doses of homologous infectious challenge virus. However, yields of infectious virus from the affected organs were reduced as compared to controls inoculated with infectious virus alone. Serial intracerebral passage of vesicular stomatitis virus in mouse brain at high doses failed to produce T particles detectable by in vitro autointerference assays on BHK(21) cells, whether or not T particles were introduced along with B virions at the first passage. When very low challenge doses of infectious B virions were inoculated intracerebrally along with high doses of homologous defective particles, there was significant prolongation of life, although most mice died eventually of slowly progressing disease. Also, the virus yields in the brains of these mice were significantly reduced, and virus was no longer detectable in the brains of "protected" mice surviving for 10 days or more. Our results suggest that although homologous autointerference does occur in vivo, it is a more complex phenomenon than in vitro cell culture experiments might indicate.

Virus-induced interference in heterologously infected HeLa cells

In doubly infected HeLa cells, poliovirus type 1 rapidly and completely dominates vesicular stomatitis virus (VSV) plaque-forming unit production. Poliovirus type 1 shuts off incorporation of amino acids into VSV-specific proteins within 2 hr after superinfection of cells already committed to massive synthesis of VSV proteins. However, poliovirus type 1 appears to have little, if any, direct effect upon incorporation of uridine into VSV-directed ribonucleic acid (RNA) synthesis. Poliovirus apparently interferes with VSV virion production only at the level of translation of viral messenger RNA, although it interferes with host cell macromolecular syntheses at the levels of translation and transcription.

RNA-dependent RNA polymerase activity in influenza virions

An RNA-dependent RNA polymerase activity has been detected in purified preparations of influenza virus. In contrast to the replicase activity induced in influenza-infected cells, the virion-associated enzyme has an absolute requirement for Mn(++). Most of the RNA synthesized in vitro is complementary to virion RNA.

Synthesis and cleavage of influenza virus proteins

The NWS strain of influenza virus grows rapidly in and kills the MDCK dog kidney cell strain. Within 1 to 2 hr, the virus inhibits host cell protein synthesis and for 3 to 4 hr more it directs the synthesis of influenza virus proteins at a rate about twice that of uninfected cell synthesis. The rates of virus ribonucleic acid (RNA) and protein synthesis reach a maximum within the first few hours after infection and then drop. Plaque assays exhibit a linear dose-response, indicating that only one virion is necessary for productive infection. We have confirmed earlier reports regarding the fragmented nature of the RNA genome of purified influenza virions. However, high resolution gel electrophoresis indicated that each size class of viral RNA is heterogenous, so that there are at least 10 and probably more fragment sizes of RNA in these virions. Repeated attempts to detect infectivity in preparations of extracted viral RNA were completely negative (over a 10(8)-fold loss of infectivity after extraction). Even infection of the "infectious" RNA-treated cells with intact, related, influenza viruses failed to support infectivity of the isolated RNA or to rescue a host range genetic marker of the RNA. Purified influenza virions exhibit only three major protein peaks based on separation according to molecular weights. These three major virion proteins are the only major virion proteins synthesized in infected cells. This is true throughout the infectious cycle from several hours after infection until the cells are dying. However, the molecular weight of these virion proteins differs slightly depending upon the cell type in which the virus is grown. No host membrane proteins are incorporated into the virions as they bud through the cell membrane. Pulse-chase labeling early after infection or prolonged chase experiments indicate that influenza virus proteins are cleaved from one or more precursor polypeptides. In fact, each of the three major peaks seems to be a heterogeneous mixture of polypeptides in various stages of cleavage. Peptide analysis confirms that the three major peaks share common peptides, but the exact precursor product relationships are not clear. There may be one or several precursor proteins. Also there could be overlapping messenger RNA molecules of varying length giving rise to polypeptides of various sizes and overlapping sequences. Late in infection, amino acid labeling shows a preponderance of internal nucleocapsid protein synthesis, indicating that either this protein is much more stable to cleavage in infection or it is made from a more stable messenger. There is no obvious relationship between virion RNA fragments and viral protein sizes, so these fragments may be artifacts.