Pneumonitis with pleural and pericardial effusion and neuropathy during amiodarone therapy

A patient with sinuatrial disease and implanted pacemaker was treated with amiodarone (maximum dose 1000 mg, maintenance dose 800 mg daily) for 10 months, for control of supraventricular tachyarrhythmias. He developed pneumonitis, pleural and pericardial effusions, and a predominantly proximal motor neuropathy. Immediate but gradual improvement followed withdrawal of amiodarone and treatment with prednisolone. Review of this and previously reported cases indicates the need for early diagnosis of amiodarone pneumonitis, immediate withdrawal of amiodarone, and prompt but continued steroid therapy to ensure full recovery.

The suitability of immunosuppressed mice kept in a standard animal unit as recipients of human tumour xenografts

CBA/Lac mice were immunosuppressed by thymectomy and whole body irradiation with 250 kVp X-rays following pretreatment with cytosine arabinoside. The optimum radiation dose for immunosuppression with prolonged survival was 7.35 Gy. The animals were kept in a standard animal unit with an overall survival rate of 83%. They were found to be suitable for large scale, long-term, xenotransplantation experiments at 20% of the cost of nude mice.

Mental illness and rehabilitation in early nineteenth-century Ireland: the case of Charles Stock

The case of a sixteen-year-old youth is presented on the basis of correspondence over the years 1806 to 1813. His initial breakdown was probably due to hebephrenic schizophrenia, but clinical detail is defective and the evidence is chiefly about the difficulties of recovery and rehabilitation. The case is discussed in relation to the treatment he received and against the background of provision for insanity and psychiatric methods and ideas in Ireland during the period.

Long term transvenous ventricular pacing in adults with congenital abnormalities of the heart and great arteries

Improved techniques of transvenous pacing have made it possible to use this approach in various congenital cardiac abnormalities. Transvenous active fixation pacing leads were implanted in seven patients aged 15 to 81 years with abnormal venous, atrioventricular, or ventriculoarterial connections with successful ventricular pacing.

Continuous subcutaneous insulin infusion in the management of painful diabetic neuropathy

Nine patients with diabetic neuropathy were treated as outpatients with continuous subcutaneous insulin infusion (CSII). Painful symptoms were scored on a 10-cm horizontal graphic rating scale; motor conduction velocity (MCV) was measured in the median and peroneal nerves; and vibration perception threshold (VPT) was recorded in the great toes. All investigations were repeated after 6 wk and at the completion of 4 mo of CSII. Improved diabetic control was confirmed by significantly lower mean blood glucose levels, M-values, and glycosylated hemoglobin. Symptomatic relief was noted by all patients and was accompanied by a significant improvement in pain scores. There was also significant improvement in VPT and MCV after 6 wk of CSII, which was maintained throughout the 4-mo period. However, sensory studies in the median nerve showed no significant changes during the study. It is concluded that strict glucoregulation is indicated in all cases of symptomatic diabetic neuropathy. It remains to be seen whether strict diabetic control from diagnosis will lead to a reduction in the incidence of this complication.

Radioimmunoassay techniques for the determination of the local release of prostaglandins and thromboxanes

Radioimmunoassay techniques are described that enable the quantification of the local release of prostaglandin (PG) E2, PGF2 alpha, TxB2 (the metabolite of thromboxane A2), and 6-keto PGF1 alpha (a metabolite of prostacyclin) from various organs in vivo. Plasma samples were acidified and the prostanoids extracted with ethyl acetate, prior to assay. The mean recovery of tritiated internal standards was 60% for 6-keto PGF1 alpha and 84% for the other prostanoids. Sample extracts were redissolved in phosphate-buffered saline and the appropriate tritiated antigen and specific antibody were added. After overnight incubation the antibody-bound and free prostanoid were separated using dextran-coated charcoal. The intraassay variation and the interassay variation were similar for all prostanoids; the mean values being 8.5% and 13.2%, respectively. There were variations in the sensitivity of the radioimmunoassay for each prostanoid. Using 250 microliter plasma samples the detection limit for PGE2 was 75 pg/ml, PGF2 alpha 50 pg/ml, TxB2 25 pg/ml, and 6-keto PGF1 alpha 125 pg/ml. These assays have been used to determine prostanoid concentrations in rats, cats, dogs, and humans.

Associations of enzymic and chromosomal polymorphisms in the seaweed fly, Coelopa frigida

Populations of seaweed fly Coelopa frigida are polymorphic at three loci determining the enzymes peptidase-1 (Pep-1), alcohol dehydrogenase (Adh) and larval esterase-2 (Es-2). Alleles at these loci have been shown by others to be non-randomly associated with each other. In the present paper we report non-random associations between the Adh and Es-2 loci and inversions on chromosome I. The two common alleles Adh-B and D are in strong linkage disequilibrium with the alpha and beta inversions, but the Adh-A and C alleles are not so. The X and Y alleles at the Es-2 locus show weak, but still significant, associations with the inversions. We consider possible linkage relationships of the loci on the chromosomal arrangements, and discuss the hypothesis that they constitute part of a coadapted gene complex whose members code for functionally related enzymes.

A comparison of the response to hyperthermia of murine haemopoietic stem cells (CFU-S) and L1210 leukaemia cells: enhanced killing of leukaemic cells in presence of normal marrow cells

When the clonogenic survival of mouse haemopoietic stem cells (CFU-S) and leukaemia L1210 cells growth as ascites tumours are compared after being heated in vitro and assayed in vivo by spleen-colony assay, there is no significant difference in the terminal slopes of the survival curves. The shoulders of the survival curves differ, but this may be explained by differences in cell kinetics. By contrast, L1210 leukaemic marrow cells are considerably more susceptible to the lethal effects of hyperthermia (43 degrees C) than either normal marrow stem cells or L1210 leukaemic cells grown as ascites tumours. Moreover, the killing of L1210 ascites cells by hyperthermia can be enhanced by heating L1210 ascites cells with an equal number of normal marrow cells, or as upernatant removed from heated marrow cells. Most cells in lukaemic marrow are normal, and it is postulated that the increased thermal sensitivity of L1210 cells in leukaemic marrow is caused by diffusible factors (e.g. lysosomal enzymes) released by heating normal marrow cells.

Selection associated with the alcohol dehydrogenase locus in Drosophila melanogaster: differential survival of adults maintained on low concentrations of ethanol

David and his collaborators have reported that adult Drosophila melanogaster survive longer on 2 per cent ethanol than on distilled water, but that the increased survival on ethanol does not occur in mutant flies lacking alcohol dehydrogenase activity. This has led us to enquire if the polymorphic alleles at the alcohol dehydrogenase locus (AdhF and AdhS), which code for enzymes with different activities, affect survival on low concentrations of ethanol. Flies were kept in sealed glass chambers containing either 2 per cent ethanol or distilled water. In four experiments, comprising a total of 126 replicates, the proportion of surviving FF flies, relative to SS, was greater on ethanol than on water. In two experiments the excess was highly significant. It appears that FF flies are better able than SS to use ethanol as food. Our results support the view that selection acts directly on the Adh polymorphism.

The construction of a recombinant cDNA library representative of the poly(A)+ mRNA population from normal human lymphocytes

A recombinant library has been constructed using the plasmid pAT153 and double stranded cDNA prepared from normal human lymphocyte poly(A)+ RNA. Transformation conditions were optimized to yield approximately 200,000 recombinants per microgram of double stranded cDNA. Statistical analysis as well as sequence complexity analysis of the inserted sequences indicates that the cDNA library is representative of > 99% of the poly(A)+ RNA present in the normal human lymphocyte.

Human erythroid burst-forming unit: T-cell requirement for proliferation in vitro

Human mononuclear leukocytes were fractionated into populations of null, T and B cells by immunoabsorbent column chromatography followed by E-rosette formation and purification of T cells by differential centrifugation and osmotic lysis. The unfractionated and fractionated cell populations were first separately cultured for 14 days in plasma clots in the presence of two international units erythropoietin. Typical erythroid burst-forming unit (BFU-E)-derived colonies grew in the unfractionated cell cultures but not from T- or B-cell cultures. BFU-E colonies grew in null cell cultures but most of the colonies were small and variably hemoglobinized with less than three subcolonies. When intact T cells were added to null cells and cocultured, many typical large BFU-E colonies with more than 10 well homogenized subcolonies appeared. Increasing numbers of large BFU-E colonies in null cell cultures were induced by stepwise addition of T cells but not by the addition of B cells. A conditioned medium in which T cells had been induced to divide by tetanus toxoid substituted for intact T cells in this T-cell-dependent BFU-E colony formation observed in null cells. These findings demonstrate that the BFU-E, a committeded erythroid stem cell, resides in the null cell fraction of peripheral blood, but its proliferative capacity and differentiation in vitro requires a soluble product of T cells. Such experiments now permit a new approach to the assessment of various disorders of erythropoiesis. Erythroid hypoplasia in a particular case may be due to dysfunction of the committed precursor cell or to a failure of a helper effect induced by T cells.

Studies of globin chain synthesis and globin mRNA content in a patient homozygous for hemoglobin Lepore

Globin chain synthesis and globin mRNA content were studied in blood cells of a patient homozygous for Hb Lepore. Peripheral blood cells incubated with tritiated leucine synthesized approximately 1.5 to 3% as many Lepore globin chains as alpha chains. Globin mRNA in peripheral blood cell RNA was assayed by molecular hybridization assays using human alpha and beta cDNA, and the results indicated the presence of approximately 1% to 2% as much beta-like mRNA (presumably deltabeta Lepore mRNA) as alpha mRNA. The amount of Lepore deltabeta chain mRNA in peripheral blood cells is therefore proportional to the amount of Lepore globin chain synthesis in the same cells. An incidental observation was the finding that peripheral blood cell RNA of this patient, at a time when she was being heavily transfused, contained substantially higher levels of beta-like mRNA (relative to alpha mRNA) than in subsequent studies. Cell-free translation of this mRNA however revealed that it contained authentic beta chain mRNA which must have been derived in some way from the transfused blood cells.

Infection in the intensive care unit

An epidemic of infection associated with Serratia marcescens and other Gram-negative organisms resistant to aminoglycosides and other chemotherapeutic agents occurred in the Intensive Care Unit, and spread to other areas of the hospital. This paper describes the problems of sepsis in the critically ill patient, outlines the occurrence of organisms in the patients concerned in this epidemic, and discusses the policies adopted to control the incidence of life-threatening infection caused by bacteria resistant to all other agents.

Supergenes in polymorphic land snails. II. Partula suturalis

The colour and banding of the shell of Partula suturalis are controlled by a single locus (M) with a series of at least six alleles. MX, giving apex as a homozygote, is dominant to MF1, giving frenata, which is dominant to the other alleles. MF2 is similar to MF1 except in its relation with MA. MF2MA produces bisecta and provides a striking example of a heterozygote that is qualitatively different from both homozygotes for the alleles producing it. MA gives atra as a homozygote and is dominant to MC and MS. MC, giving cestata as a homozygote, is recessive to all except MS. MS, giving strigata, is the universal recessive. It is suggested that the locus may be complex. The direction of coiling of the shell is determined by the H locus with HS (sinistrality) dominant to HD (dextrality). The expression of coiling is delayed by one generation, the maternal genotype determining the phenotype of the offspring. M and H are not linked. Self-fertilisation occurs infrequently and non-randomly.

Commitment to erythroid differentiation by friend erythroleukemia cells: a stochastic analysis

A method for the clonal analysis of murine erythroleukemia cells has been developed which allows the precise characterization of the number of progeny produced by each cell and the degree of differentiation of each progeny cell. The potential of almost every cell in the culture can be monitored because a plating efficiency close to 100% has been achieved. The effects of treatment with an inducer of differentiation (DMSO) on the proliferative capacity of the treated cells have been studied with this technique. Cells from a mass culture treated with inducer give rise to colonies of differentiated progeny when subsequently cloned in the absence of inducer. Colonies exhibiting this phenotype represent the progeny of cells committed to the differentiation pathway by treatment with inducer. We observe that the commitment decision limits the subsequent proliferative capacity of the cell to four additional cell divisions. A quantitative analysis suggests that the commitment decision for each cell is made in a stochastic manner. Irreversible commitment to the expression of differentiated functions occurs with discrete probability per cell generation for many cell generations. The value for this probability is a function of the concentration of inducer (DMSO). A correlative biochemical study suggests that an irreversible commitment decision by a significant proportion of the population precedes or accompanies increases in cytoplasmic globin mRNA levels, one of the earliest detectable biochemical markers for erythroid differentiation in this system. A specific kinetic model based on these considerations has been developed to predict clonal phenotypes as a function of time and probability of commitment. Quantitative predictions based on this model are in excellent agreement with experimental observations. The effectiveness of a stochastic model in predicting the behavior of this system is discussed in relation to the stochastic behavior of normal hematopoiesis and the biochemical mechanisms which control these differentiation programs.