The enzymatic and release characteristics of sheep neutrophil elastase: a comparison with human neutrophil elastase. Sheep are often used to study tissue damage following shock after traumatic injury and in the course of other diseases. The processes involved are thought to be caused at least in part by elastase released from polymorphonuclear leukocytes (PMNs). Since little is known about elastase and its role as a mediator of tissue damage in sheep, we studied the biochemical properties and release characteristics to sheep leukocyte elastase (SLE) in comparison of those of human leukocyte elastase (HLE). Both enzymes showed similar molecular masses, amino-acid compositions, N-terminal amino-acid sequences, and abilities to digest elastin substrates. Differences, however, were found in kinetic parameters measured with the elastase-specific substrate N-methoxysuccinyl-(L-alanyl)2-L-prolyl-L- valine-4-nitroanilide (MeoSuc-AAPV-pNa). The Michaelis constant (Km) of ovine elastase was nearly 10 times higher (1.82 mM) than the Km of HLE (0.21 mM). Values of SLE calculated for kcat were 70% and for kcat/Km 8% of corresponding values determined for HLE. In addition, significant differences between sheep and human PMNs were found in in vitro stimulation experiments. In contrast to human PMNs, sheep neutrophils released no active elastase, and only 50 to 70% of the H2O2 produced by human PMNs. This failure to release active elastase could not be explained by a lower elastase content of sheep PMNs, as there were no significant differences found between the elastase contents of sheep and human PMNs. We conclude that elastase liberated by stimulated sheep PMNs is inactivated by a concomitantly released proteinase inhibitor also located within the sheep PMNs.(ABSTRACT TRUNCATED AT 250 WORDS)


Microbial metabolism of quinoline and related compounds. XV. Quinoline-4-carboxylic acid oxidoreductase from Agrobacterium spec.1B: a molybdenum-containing enzyme. The quinoline-4-carboxylic acid oxidoreductase from Agrobacterium spec.1B was purified 84-fold to apparent homogeneity with 15% recovery, using ammonium sulphate precipitation, heat precipitation, hydrophobic interaction, anion exchange- and gel chromatography. The molecular mass of the native enzyme was estimated to be 320 kDa by gel filtration. SDS-polyacrylamide gel electrophoresis of the enzyme revealed three protein bands corresponding to 85, 35 and 21 kDa. Per molecule the enzyme contains 8 atoms of iron, 8 atoms of acid-labile sulphur, 2 atoms of molybdenum, 2 molecules of FAD and as molybdenum cofactor, molybdopterin cytosine dinucleotide. Besides quinoline-4-carboxylic acid the enzyme also catalysed the conversion of quinoline, 4-chloroquinoline and 4-methylquinoline to the corresponding 2-oxo-1,2-dihydroderivatives. Cyanide, methanol, 4-chloromercuribenzoate and acriflavin were effective inhibitors.


Anisoosmostic liver perfusion: redox shifts and modulation of alpha-ketoisocaproate and glycine metabolism. 1) In isolated perfused rat liver, 14CO2 production from [1-14C]alpha-ketoisocaproate or [1-14C]glycine as well as ketogenesis from alpha-ketoisocaproate were stimulated upon exposure to hypoosmotic perfusion media, whereas hyperosmotic exposure inhibited. The effects of anisotonicity were preserved when ketogenesis from alpha-ketoisocaproate and 14CO2 production from [1-14C]glycine were already stimulated by glucagon. On the other hand, ketogenesis from tyrosine (2 mM) or octanoate (0.1 mM) were almost unaffected by anisoosmotic exposure. 2) With all ketogenic substrates studied, hypoosmotic (hyperosmotic) cell swelling (shrinkage) decreased (increased) the beta-hydroxybutyrate/acetoacetate ratio in effluent perfusate. A shift of the mitochondrial and cytosolic NADH systems to a more oxidized (reduced) state following hypoosmotic (hyperosmotic) exposure was also found upon infusion of beta-hydroxybutyrate/acetoacetate and lactate/pyruvate as redox indicator metabolite couples. The effects of anisotonicity on the beta-hydroxybutyrate/acetoacetate ratio were reversible upon normoosmotic reexposure and persisted throughout anisoosmotic exposure despite completion of volume regulatory K+ fluxes within 10-15 min. Hepatic oxygen consumption decreased by about 10% during hyperosmotic cell shrinkage and was transiently stimulated during hypoosmotic exposure. 3) There was a close relationship between ketogenesis from alpha-ketoisocaproate (0.5 mM) and the mitochondrial redox state, as assessed by the beta-hydroxybutyrate/acetoacetate ratio in effluent, regardless of whether the pathway was modulated by anisotonicity or glucagon. 4) Isoosmotic cell swelling induced by addition of glutamine (3 mM) was without significant effect on ketogenesis from octanoate and stimulated ketogenesis and 14CO2production from [1-14C]alpha-ketoisocaproate only slightly (i.e. by less than 10%); however, in each case the hydroxybutyrate/acetoacetate ratio in effluent perfusate decreased by about 20% upon addition of glutamine. 5) Stimulation of 14CO2production from [1-14C]glycine by hypoosmotic exposure and glucagon was only slightly affected when the accompanying decrease of the beta-hydroxybutyrate/acetoacetate ratio was reversed by addition of beta-hydroxybutyrate. 6) The data are compatible with a hypotonicity (hypertonicity)-induced shift of the mitochondrial NADH system to a more oxidized (reduced) state, probably due to a alterations of respiration. Mitochondrial swelling probably also occurs under the influence of glutamine. Modulation of ketogenesis from alpha-ketoisocaproate, but not of glycine oxidation by anisoosmotic exposure and glucagon can be related to the accompanying redox shifts. The observations support the concept that cell volume may be an important parameter determining liver cell function.


Development and optimization of an enzyme-linked immunosorbent assay employing two murine monoclonal antibodies for absolute quantitation of human beta-glucuronidase. We have developed and optimized an enzyme-linked immunosorbent assay (ELISA) for absolute quantitation of human beta-glucuronidase. This is a double antibody sandwich system employing two murine monoclonal antibodies specific for human beta-glucuronidase developed in our laboratories. The method involves (a) coating of the high binding polystyrene microtitration plate with the first antibody (7B6 IgG), (b) blocking of remaining active sites with 3% bovine serum albumin in phosphate-buffered saline, (c) application of samples, (d) addition of the biotinylated second antibody (6D2 IgG), (e) addition of streptavidin-horseradish peroxidase, and (f) development of color with o-phenylenediamine dihydrochloride-H2O2 and reading in a microplate reader at a wavelength of 490 nm. The method is highly sensitive with an optimal range of 10 to 100 ng/ml of the enzyme and is reproducible with intraday and interday precisions of 3.2 and 4.1%, respectively. The enzyme contents of 20 urine and 20 bile samples quantitated by this ELISA method were, respectively, 148 +/- 101 and 6380 +/- 3780 ng/ml (means +/- SD) which correlated well with their enzyme activities. Such a method for absolute quantitation of human beta-glucuronidase is essential for studying its pathophysiologic roles in cholelithiasis and carcinogenesis and can also be used clinically as an indicator for tissue damage or malignancy.


Enzymatic properties of polyethylene glycol-modified cholesterol esterase in organic solvents. The solvent dependency and substrate specificity of polyethylene glycol (PEG)-modified cholesterol esterase (CEH) catalyzing cholesterol ester synthesis in organic solvents were studied. When cholesterol and linoleic acid were used as the substrates, PEG-modified CEH synthesized cholesterol linoleate only in water-immiscible organic solvents. Among some solvents capable of solubilizing all of the reaction components (PEG-modified CEH, cholesterol, and linoleic acid), chloroform was most suitable for enzymatic cholesterol linoleate synthesis, and the synthetic activity for cholesterol linoleate decreased in the order chloroform, benzene, toluene, and cyclohexane. PEG-modified CEH synthesized various cholesterol esters with significant substrate specificity. The substrate specificity for cholesterol ester synthesis in benzene was analogous to that for cholesterol ester hydrolysis in aqueous solution.


Partial purification and immobilization of ribonuclease T2. A simple procedure, consisting of water extraction, heat treatment at pH 2.0, negative adsorption on DEAE-cellulose at pH 4.9, and concanavalin A-Sepharose chromatography, was developed for the partial purification of ribonuclease (RNase) T2 from taka-diastase powder with an overall yield of 5.5%. The partially purified enzyme when coupled to aminoethyl Bio-Gel P-60, retained 12-16% of the activity of the soluble enzyme. Temperature stability studies on RNase T2 bound to matrices, activated with increasing concentrations of glutaraldehyde, and the influence of lysine modification on the activity of the soluble enzyme revealed that the low activity observed for the gel-bound enzyme is probably due to the masking of the active site of the enzyme as a result of the involvement of lysine residues, situated near the active site, during coupling. Immobilization did not affect the pH and temperature optima of RNase T2. On repeated use, the bound enzyme retained approximately 55% of its initial activity after six cycles. These results are discussed, taking into consideration the factors affecting immobilized enzymes.


Cloning and expression of the Erwinia herbicola tyrosine phenol-lyase gene in Escherichia coli. The tyrosine phenol-lyase (TPL) gene of Erwinia herbicola was cloned and expressed in Escherichia coli, and the complete nucleotide sequence of the gene determined. The TPL gene comprises 1368 bp, encoding 456 amino acids which have 90% amino acid identity with TPL from Citrobacter freundii. After replacing the 5'-flanking region of the TPL gene with the E. coli lac promoter, TPL protein could be hyperproduced constitutively in E. coli without induction by L-tyrosine.


Handling of cytotoxic drugs by healthcare workers. A review of the risks of exposure. Increasing utilisation of chemotherapeutic agents in treating patients with malignancy has led to the potential for widespread exposure of healthcare workers who come into contact with patients or these agents in the work place. Unfortunately, these drugs are toxic to both the abnormal and normal somatic cell. This occurs in the patient, and is also likely to affect any individual exposed. There appear to be widely divergent opinions concerning the extent of hazard of coming into contact with these agents, in spite of which caution and minimising exposure risk seems only prudent and appropriate.


Adverse effects of diuretics.

Adverse effects of diuretics. Analysis of the available evidence indicates that diuretics do not increase coronary heart disease morbidity and mortality. The multiclinic trials supporting the cardiotoxicity hypothesis are few in number and flawed in design. The majority of the trials, including the well designed trials, indicate no excess of coronary heart disease (CHD) events in diuretic-treated patients compared with those given other drugs or placebo. Recent studies indicate no increase in cardiac arrhythmias after diuretic treatment. Also, although depletion of intracellular potassium and magnesium occurs in patients with congestive heart failure even without diuretics, intracellular concentration of these ions is not significantly reduced by diuretics in patients with uncomplicated hypertension. Modest elevations of serum cholesterol may occur during the first 6 to 12 months of treatment with thiazide diuretics. However, after this time these elevations fall to or below the pretreatment level. The fall may be greater in patients receiving other drugs but the differences are small and their clinical significance is questionable. The incidences of hyperglycaemia and diabetes were only minimally increased in long term clinical trials while the importance of hyperinsulinism and insulin resistance in causing CHD remains unproven in patients. Thiazides remain, therefore, a safe and effective treatment for patients with hypertension.


Acute ketotifen overdosage. A review of present clinical experience. Ketotifen (Zaditen) is a widely used prophylactic antiasthmatic drug with pronounced antianaphylactic properties and a specific H1-antihistaminic effect. This article summarises the available information on acute overdosage of this drug, which was reported in 13 adults and 8 children. The symptoms of acute overdosage observed with ketotifen are similar to those described for antihistaminic agents. However, it would appear that the acute toxicity of ketotifen is rather low, since no serious effects have been reported either in children or in adults after the intake of up to 20mg of ketotifen, which is 10 times the recommended dose. No lethal outcome of acute overdosage has been described in association with this drug. Ketotifen seems to be better tolerated in children than in adults. Based on present clinical experience, management of acute overdosage includes gastric lavage within 2 to 4h after ingestion or activated charcoal after this period. Symptomatic treatment is indicated if arrhythmias, hypotension or seizures develop, and the patient should be kept under surveillance for at least 6 to 8h.


Adverse drug reactions to systemic antifungals. Prevention and management. Systemic administration of antifungal agents for invasive mycoses has dramatically increased over the past 10 years in many fields of medicine. The increase has been due both to an increasing immune compromised population and to potent antibacterial agents which allow these fungi to invade tissue. It is apparent that our understanding of the use of both the old and new antifungal agents has significantly increased in the last few years. In this review, we attempt to document our extensive knowledge of the adverse effects of the polyenes, flucytosine, griseofulvin and azoles when given systemically for treatment. Interwoven in this documentation of the adverse reactions to these agents is the attempt to help clinicians potentially avoid some of these adverse effects and if they do occur, to be able to identify and successfully manage them.


New insights into T-cell antigen receptor structure and signal transduction. Recent studies have provided insights into how the complex structure of the T-cell antigen receptor relates to its signal transduction function. Both the CD3 and zeta subunits contain functioning signaling modules that regulate the activation of tyrosine kinases and phosphorylation of cellular substrates.


Protein calorie malnutrition and cancer therapy. Anorexia and cachexia frequently complicate the late stages of malignancy and may be a prominent feature of early disease. The resulting weight loss often becomes a major focus of concern for the patient and the family and may significantly add to the morbidity and mortality of cancer. Factors which contribute to the wasting syndrome include the effects of the tumour, effects of chemotherapy, abnormalities of carbohydrate, fat and protein metabolism and the cytokine response. Administration of total parenteral nutrition (TPN) is an important method of addressing malnutrition, particularly in patients with nonfunctioning gastrointestinal tracts. A critical review of the TPN cancer literature is provided along with a discussion of new approaches and future directions in the nutritional support of patients with malignant disease, such as anabolic agents, hydrazine sulfate and megestrol.


B-cell activation.

B-cell activation. Extraordinary progress has been made in refining our understanding of the B-cell antigen receptor complex, the role of protein-tyrosine phosphorylation as the key intermediary in immunoglobulin signal transduction, and in identifying candidate effectors of immunoglobulin-mediated signaling. In addition, the properties of a new group of G proteins may rekindle interest in older observations implicating such molecules as important in B-cell activation.


Signal transduction by T- and B-cell antigen receptors: converging structures and concepts. Recent evidence demonstrates that the antigen receptor complexes of T and B lymphocytes are very similar in general architecture and primary and secondary structure of component polypeptides, and that they use common mechanisms for transmembrane signal transduction. Most importantly, multiple subunits of each receptor (Ig-alpha, Ig-beta and Ig-gamma, CD3 gamma, CD3 delta and CD3 epsilon, and T-cell receptor zeta and eta) possess a motif of approximately 26 amino-acids, denoted ARH1, which appears to carry sufficient structural information for receptor-mediated lymphocyte activation.


Clinical toxicity of interleukin-2.

Clinical toxicity of interleukin-2. Interleukin-2 (IL-2) is increasingly used to treat patients with cancers refractory to conventional treatment. Flu-like syndromes are extremely frequent but usually mild. A variety of skin complications (mostly erythema and mucositis) have been reported. Life-threatening skin reactions have also been described. Acute reactivation of psoriasis can also occur. Immediate hypersensitivity reactions have so far not been described, but IL-2 treatment has been shown to predispose to acute hypersensitivity reactions to iodine-containing contrast media. Hypothyroidism is the major endocrine complication and antithyroid antibodies have been detected in approximately 50% of patients. Neurological and psychiatric disturbances with moderate or severe mental status changes are common and sometimes treatment-limiting. The occurrence of peritumoural oedema in patients with brain metastases can also be a major practical problem. Musculoskeletal disorders are transient and resolve spontaneously. The vascular leak syndrome is the most frequent and severe complication of IL-2 of which weight gain, generalised oedema, hypotension and impaired renal function are the main features. Even though a damaging effect on vascular endothelium cells by various cytokines released by activated lymphoid cells or mediated by non-lymphocyte-dependent factors has been proposed to be involved, the mechanism remains unclear. Other cardiovascular injuries, possibly life-threatening, including myocarditis, angina pectoris and myocardial infarction, can occur during the first days of treatment. Supraventricular arrhythmias are the most common rhythmic disorder. Decreases in myocardial contractility and haemodynamic pattern similar to those of septic shock have been encountered in most cases. Acute renal dysfunction is common but resolves with symptomatic management. Intrahepatic cholestasis with hyperbilirubinaemia is observed in most patients but permanent liver damage has not been described. Several cases of pancreatitis have been reported. Anaemia, thrombocytopenia, lymphocytopenia and eosinophilia are frequent and occur in most if not all patients. Some data suggest a high incidence of infectious complications, particularly in patients with surgically tunnelled catheters, but marked flu-like syndromes may be confounding. Finally, death directly related to IL-2 treatment has been noted in less than 1% of all patients. Investigations are under way to minimise IL-2 toxicity with varying dose regimens and combined treatments.


Costimulation of T-cell growth.

Costimulation of T-cell growth. The specificity of T-cell recognition is dictated by the interaction of the T-cell receptor with MHC-peptide complexes. The biological consequences of such recognition is determined, however, by costimulatory pathway(s). Recent studies have led to the identification of receptor-counter-receptor pairs that may regulate T-cell costimulation.


Neuropsychiatric reactions to nonsteroidal anti-inflammatory drugs (NSAIDs). The New Zealand experience. The New Zealand Medicines Adverse Reactions Committee has been monitoring reports of adverse drug reactions (ADRs) since 1965. We wished to determine the numbers of voluntary reports of different types of ADR to all nonsteroidal anti-inflammatory drugs (NSAIDs) over a long time period and relate these to age. As the elderly are known to suffer from neuropsychiatric adverse effects of many drugs, we investigated neuropsychiatric reactions to NSAIDs to determine whether these were more commonly reported in the elderly. We counted all reported ADRs suspected to be associated with NSAIDs as well as selected types of ADRs reported from 1970 to 1989. These were divided into 5-year periods and 10-year age groupings. In each consecutive 5-year period there was a progressive increase in the numbers of all ADRs reported for all NSAIDs. This was particularly marked above 50 years of age, but the numbers were reduced above 80 years. Reports for females accounted for about two-thirds of all reactions. Not unexpectedly, alimentary and dermatological ADRs accounted for most reactions and were more common in the group above 50 years. Overall, neuropsychiatric reactions were the third most common ADR type reported. Their numbers increased with age and peaked in the 50 to 59 age group, with a sharp decline after 69 years. This age distribution paralleled that for all ADRs to NSAIDs. Although neuropsychiatric reactions to NSAIDs were reported in all age groups, they were not reported more commonly in the elderly. This study suggests that neuropsychiatric reactions to NSAIDs may be more frequent than is commonly believed.


Interleukin-2.

Interleukin-2. In the past year there have been significant advances in understanding the role of interleukin-2. Its role in the activation of T cells by antigen-presenting cells, the structure-activity relationships between interleukin-2 and its receptor and the subsequent signaling have all become clearer. The creation of mice with a specific defect in the interleukin-2 gene has given us a clearer idea of its role in vivo. Recent studies also suggest that interleukin-2 may finally find a role in immunotherapy.


Mechanisms of lymphocyte homing.

Mechanisms of lymphocyte homing. The initiation and maintenance of an effective immune response requires the coordinated function of spatially distinct compartments of the immune system. Such coordination is critically dependent on mechanisms of lymphocyte homing and recirculation. The past year has been significant progress in our understanding of both the molecular basis of these homing mechanisms, and their potential physiological consequences.


Adverse effects of general anaesthetics. This review deals with the adverse reactions associated with general anaesthetic agents in current use. These reactions fall into 2 categories; those which are more common, predictable and often closely related, and those which are rare, unpredictable and carry a high mortality. Both inhalational and intravenous anaesthetic agents affect the central nervous and cardio-respiratory systems in a dose-related manner. Neuronal inhibition results in decreasing levels of consciousness and depression of the medullary vital centres which can lead to cardiorespiratory failure. Both groups of agents have some depressant effect on the myocardium and vascular smooth muscle leading to a fall in cardiac output and hypotension. Centrally-mediated respiratory depression is common to both groups and the inhalational agents have a direct effect on lung physiology. The most important idiosyncratic reactions to the volatile agents are malignant hyperpyrexia and 'halothane hepatitis'. Malignant hyperpyrexia has an incidence of 1:12,000 with a mortality of about 24%. It is triggered most often by halothane together with suxamethonium. Post halothane hepatic necrosis is rare. Evidence points to 2 distinct syndromes; direct toxicity from the products of reductive metabolism, and a more serious illness, immunologically mediated via haptens formed by liver proteins and the products of oxidative metabolism. Prolonged nitrous oxide exposure can cause bone marrow depression and life-threatening pressure effects by expansion of air-filled spaces within the body. The idiosyncratic reactions to the intravenous agents include anaphylactoid reactions (which are rare) and triggering of acute porphyria. Etomidate is immunologically 'clean', but it inhibits cortisol synthesis.


Lymphocyte homing to sites of inflammation. The identification by monoclonal antibodies and gene cloning of the major receptors, the integrins, selectins and endothelial adhesion molecules, involved in lymphocyte adhesion and migration has advanced our understanding of the molecular interactions between lymphocytes and endothelial cells in the past few years. These antibodies and soluble receptors are being applied as reagents for studying the in vivo expression of adhesion molecules, the importance of which in various types of inflammation is being recognized.


The interleukin-4 family of lymphokines. Evidence has accumulated indicating that four T-cell derived lymphokines, interleukin-4, interleukin-5, granulocyte-macrophage colony stimulating factor and interleukin-3, are closely related. The genes encoding these lymphokines are clustered within a region of 1000 kb, the proteins have a common secondary and spatial organization, and their corresponding receptors are all members of the haemopoietin family of receptors.


Interleukin-5.

Interleukin-5. Interleukin-5 is a dimeric cytokine that controls the differentiation of B cells into antibody-secreting cells as well as inducing the growth of Ly-1(CD5)+ B cells and B-cell tumors. It also has a major role of the growth and differentiation of eosinophils. Rapid progress has been made during the last year in the delineation of the structure and activities of interleukin-5, and the molecular nature of its functional receptors. Interleukin-5 exerts pleiotropic activities on various target cells through a high-affinity receptor which is composed of two different polypeptide chains, alpha and beta. The alpha chain binds interleukin-5 with low affinity and the beta chain has been identified as the interleukin-3 receptor-like protein and is also the beta chain of the granulocyte-macrophage colony stimulating factor receptor.


Mechanisms of soluble mediators.

Mechanisms of soluble mediators. A two chain model, composed of ligand-binding and signal transducing subunits, first identified in the interleukin-6 receptor system, has been revealed in several other cytokine systems. Common signal transducers shared by several receptor systems may explain a functional redundancy characteristic of cytokines. The signaling pathway from the receptor to gene activation is now becoming clearer due to the successful molecular cloning of several transcription factors.


Interleukin-10.

Interleukin-10. Despite the short history of interleukin-10, accumulated evidence indicates that this interleukin plays a major role in suppressing immune and inflammatory responses. Yet interleukin-10 also maintains cell viability and acts as a cofactor to promote the growth of lymphoid and myeloid cells in vitro. Here we review the present knowledge on the structure and function of interleukin-10.


Interferon-gamma.

Interferon-gamma. During the past year, the most striking progress in our understanding of interferon-gamma has been made in the elucidation of the three-dimensional structure of the molecule and in the analysis of the molecular structure and the functional domains of the interferon-gamma receptor. A greater insight into the molecular mechanisms of gene activation by interferon-gamma has been gained, and the immunoregulatory role of interferon-gamma has been better defined in studies dealing with its effects on B-cell function and with its production by the various T-cell subsets. Finally, the effects of interferon-gamma on intracellular parasites is an important aspect of interferon-gamma activity that is giving rise to several clinical trials.


T helper cells.

T helper cells. B-cell proliferation and differentiation is controlled by T helper cells. Recent studies have determined that the expression of a novel, 39 kD, T-cell membrane protein is responsible for inducing T-cell-dependent B-cell activation. The receptor for this protein on the resting B cell is CD40. Once activated, B cells are induced to grow and differentiate by the elaboration of interleukin-4 and interleukin-5 from activated T cells. Together, T cell-B cell contact and soluble factors provide all the signals required for B-cell growth and differentiation.


Cell-mediated cytotoxicity.

Cell-mediated cytotoxicity. Progress is being made in determining how cytotoxic cells are activated, the way the lethal hit is delivered and the subsequent events in the target cell. Several factors cloud the issue, including the heterogeneity of cytotoxic cells, differences between fresh cells and cell lines, and the possibility of single cells using multiple cytotoxic mechanisms. The most difficult task will be to define which cytotoxic mechanisms are significant in vivo.


Macrophage activation by T cells.

Macrophage activation by T cells. In the past year, the application of biochemical and molecular approaches to the analysis of macrophage activation by T cells has provided new information concerning the regulation of gene expression during the activation process, and advanced our understanding of the multiple mechanisms that influence the development of macrophage function during an immune response.


Immunosuppressive therapy.

Immunosuppressive therapy. Although Cyclosporin A has improved transplant outcome, its use has serious limitations due to its narrow therapeutic window. New approaches to broaden this window exploit alternative drug formulations, pharmacokinetic profiling and new immunosuppressive agents, such as Rapamycin and Brequinar, which act in a synergistic fashion. There is no evidence to suggest that the pharmacological alternative to Cyclosporin A, FK-506, displays a broader therapeutic window, although it may be tenfold more potent. Similarly, despite the specificity of the IgG2a mouse anti-human CD3 monoclonal antibody, it displays a significant range of clinical side effects, delayed therapeutic action and frequently stimulates generation of human anti-mouse monoclonal antibodies. Recent advances in monoclonal antibody technology seek not only to produce antibodies against determinants involved in alloactivation, but also to 'humanize' the antibodies for reduced side effects. The availability of this array of potential agents highlights the need to develop guidelines for clinical trial methodologies to address the unique needs and demands of organ transplantation.


Cellular mechanisms of rejection.

Cellular mechanisms of rejection. Studies by molecular biologists, protein chemists and cell biologists are rapidly providing new tools and information for those interested in the cellular mechanisms of graft rejection. Despite these contributions, a clear picture of the mechanisms involved in rejection has not yet evolved. However, whole new areas for research have developed, providing opportunities for new insights as well as therapeutic interventions.


The use of colony stimulating factors in clinical bone marrow transplantation. The use of colony stimulating factors in clinical bone marrow transplantation is rapidly evolving. Both granulocyte colony stimulating factor and granulocyte macrophage colony stimulating factor have shown efficacy in bone marrow transplant patients in accelerating the rate of myeloid recovery. The use of colony stimulating factor primed peripheral blood progenitor cells appears to accelerate platelet recovery as well as myeloid recovery.


Graft versus host disease following allogeneic bone marrow transplantation. Graft versus host disease is a major barrier in allogeneic bone marrow transplantation. The associated morbidity and mortality need to be understood and prevented if possible, as the potential indications for bone marrow transplantation continue to broaden. Areas of investigation include the cellular effector arm as well as the cytokines associated with the expression of the disease.


Organ acceptance and rejection.

Organ acceptance and rejection. During the past year, transplantation scientists have continued the quest for their version of the Holy Grail, developing and expanding model systems aimed at improving allograft survival. The highlights include further analyses of tolerance induction by intrathymic inoculation of allogeneic tissue, the use of oral tolerance to MHC antigens to improve graft survival, and expansion of the model of bone marrow transplantation to achieve solid organ tolerance in a large animal model and humans. Immunogeneticists have provided data on improved graft survival when MHC matching was performed at the molecular level.


Cytokines in rodent reproduction and the cytokine-endocrine interaction. Insights derived from recent studies employing rodent models demonstrate that the synthesis of pluripotent cytokines is an important function of resident cells in the female reproductive tract. Through steroid hormone regulated secretion of these mediators, resident cells appear to coordinate the recruitment and action of leukocytes that are centrally implicated in the dramatic remodelling processes characteristic of reproductive events.


Immunobiology of pregnancy.

Immunobiology of pregnancy. This report presents new findings on two conditions that permit genetically disparate tissues to coexist during pregnancy: (a) regulation of major histocompatibility genes in placental trophoblast, and (b) synthesis of uterine and placental polypeptide growth factors with immunosuppressive properties. Recent experiments examining inter-relationships between these two protective mechanisms are cited, and potential explanations for trophoblast resistance to factors with MHC-inducing properties are proposed.


Vaccines against fertility.

Vaccines against fertility. The first evidence for the efficacy of a birth control vaccine in humans is now available from the Phase II trials on the human chorionic gonadotrophin vaccine in India. Several sperm antigens have been identified as potential contraceptive immunogens and zona pellucida antigens have been reported that reversibly control fertility.


Molecular definition of tumor antigens recognized by T lymphocytes. Several tumor antigens recognized by T cells have now been identified at the molecular level. Various mechanisms can account for their expression: activation of normally silent genes; point mutations; chromosome translocations; and post-translational modifications of proteins. This led to the notion that potential tumor-rejection antigens can be shared by a significant proportion of human tumors. This may have important implications in cancer immunotherapy, especially since tumors expressing a defined antigen can be identified on the basis of the expression of the relevant gene.


MHC antigens and cancer: implications for T-cell surveillance. Evidence for a direct involvement of cell-mediated immune mechanisms in the control of human tumours remains sketchy. The past year, however, has seen advances in our understanding of the relationship between the immune system and tumour cells, and has given rise to new prospects for immunological treatment and the prevention of cancers.


New strategies for active immunotherapy with genetically engineered tumor cells. While previous tumor vaccine strategies have shown intriguing results, clearcut efficacy has been difficult to establish in human trials. Recently, newer approaches have been developed in animal systems that modify tumor cells genetically so that they express new antigens or secrete certain cytokines. Engineering tumor cells to secrete cytokines in a paracrine fashion can induce powerful local cytokine effects without producing significant systemic toxicity. In addition to local inflammation, this approach can alter the presentation of tumor antigen or activation of tumor antigen-specific T lymphocytes, resulting in systemic antitumor immunity.


Construction of cancer vaccines with carbohydrate and protein (peptide) tumor antigens. Tumor vaccinology is as old as immunological thought and as young as our rapidly evolving understanding of antigen processing and presentation. The recent availability of carbohydrate and peptide tumor antigens suitable for vaccine construction, conjugate and recombinant vector technologies capable of augmenting helper and cytotoxic T cell activity and potent new immunological adjuvants have combined to produce considerable optimism for the future of tumor vaccines.


Immunogenetics of cell surface antigens of human cancer. Hybridoma technology, immunohistochemistry and molecular genetic techniques have paved the way for a general serological mapping of molecules expressed on the surface of normal and neoplastic cells. The emerging findings challenge cell lineage-based models of differentiation and point to new, modular concepts to explain complex tumor phenotypes. In parallel studies, the repertoire of T-cell recognized tumor antigens--still mysterious but probably quite distinct from the antibody-defined repertoire--has also become accessible to molecular analysis.


Monoclonal antibodies in the study and therapy of hematopoietic cancers. Recent advances utilizing monoclonal antibodies to phenotype acute leukemias have revealed no prognostic significance of the expression of lymphoid-associated antigens by acute myeloid leukemia blasts and conflicting results regarding 'biphenotypic' acute myeloid leukemia. Several studies treating patients with refractory lymphoma with immunotoxins reported encouraging results but significant production of anti-mouse or anti-toxin antibody. Radiolabeled antibodies that react with panhematopoietic antigens have delivered selective radiation to marrow, spleen and lymph nodes in animal models and are being used in Phase I studies of marrow transplantation for acute leukemia.


Monoclonal antibodies in the detection and therapy of micrometastatic epithelial cancers. The initial promise of monoclonal antibodies as major therapeutic agents in human epithelial cancer has not been realized. Inaccessibility of cells in solid tumors due to factors such as the nature of the vascular endothelia and high pressure in the tumor are primarily responsible for the failure of antibody therapy. Although new strategies employing recombinant antibodies and immunoglobulins designed to actively engage the immune system may prove beneficial, micrometastatic tumor cells (at the stage of minimal residual disease) are likely to be the only suitable targets for antibody therapy. The diagnostic approaches to identify and characterize these cells and their use for prognosis and monitoring adjuvant immunotherapy is discussed.


Strong binding of single-stranded DNA by stem-loop oligonucleotides. We report that oligodeoxynucleotides which form stem-loop hairpin structures and which have pyrimidine-rich loops can form strong complexes with complementary single-stranded DNA sequences. Stem-loop oligonucleotides were constructed with a 25-nt T-rich loop and with variable Watson-Crick stems. The complexes of these oligomers with the sequence dA8 were studied by thermal denaturation. Evidence is presented that the complexes are one-to-one, bimolecular complexes in which the pyrimidine loop bases comprise the outer strands in a pyr.pur.pyr triplex, in effect chelating the purine strand in the center of the loop. Melting temperatures for the loop complexes are shown to be up to 29 degrees C higher than Watson-Crick duplex of the same length. It is shown that the presence of a stem increases stability of the triplex relative to an analogous oligomer without a stem. The effect of stem length on the stability of such a complex is examined. Such hairpin oligomers represent a new approach to the sequence-specific binding of single-stranded RNA and DNA. In addition, the finding raises the possibility that such a complex may exist in natural RNA folded sequences.


Structure of poly d(A).poly d(T).

Structure of poly d(A).poly d(T). On the basis of the x-ray data from polycrystalline and well oriented fibers of the sodium salt of poly d(A).poly d(T) (Arnott et al, Nucl. Acids Res. 11, 4141-4155 (1983), a revised B'-DNA model incorporating B-like adenine and thymine strands is shown to give a much better x-ray agreement (R = 0.25) than the previously assigned model consisting of mixed sugar conformations in the two strands. The narrowing of the minor and the widening of the major grooves are promiscuous features of B'-DNA, which are common to all poly d(purine).poly d(pyrimidine) duplexes with two hydrogen bonded base-pairs and are in marked contrast with classical B-DNA. Due to modest propeller (-15 degrees), the cross strand diagonal hydrogen bonds (0.37 nm) in this duplex are not as strong as those in A,T-rich oligonucleotide crystal structures.


Ultraviolet resonance Raman marker bands of the right to left helix structure transitions in DNA and polynucleotide model compounds. The right to left helix structural transition in purine-pyrimidine alternating copolymers has been extensively studied by vibrational spectroscopies, amongst many other experimental approaches. Here, the use of resonance Raman spectroscopy in the ultraviolet region (223-, 257- and 281 nm excitation wavelengths) to monitor such structural changes is reviewed in the light of new results obtained on poly(dA-dC).poly(dG-dT) on one hand, and the previous results obtained on poly(dG-dC)2, poly(dA-dT)2 and natural DNA (Chicken erythrocytes) on the other. It is now possible to define B----Z transition marker bands involving the proper bases, which show a similar behaviour on structural transition whatever the composition of alternating purine-pyrimidine sequences: the 1580- and 1487 cm-1 lines of the purines, the 1486- and 1294 cm-1 lines of the pyrimidines are good markers in the vibrational spectra recorded at various UV excitation wavelengths.


Salt-induced conformational transition of poly(d2NH2A-dT) studied by ultraviolet resonance Raman spectroscopy. The conformational changes of poly(d2NH2A-dT) in aqueous solution, induced by increasing the NaCl concentration from 0.1M to 4M, have been monitored by ultraviolet resonance Raman spectroscopy, in using the 222-, 257- and 281 nm excitation wavelengths. These changes have been interpreted in comparing the polymer spectra to those of the mononucleotide compounds on one hand, and to those of other alternating purine-pyrimidine polymers on the other hand, i.e. poly(dG-dC) and poly(dA-dT) which showed a B to Z transition in going from low- to high salt concentrations. The high salt poly(d2NH2A-dT) spectra do not show any Raman marker line of the Z conformation. The spectroscopic results indicate that most of the ribose puckering goes from C2'-endo/anti to C3'-endo/anti in increasing the salt concentration. In addition the base stacking interactions, to which the resonance Raman effect is very sensitive, are not drastically changed upon salt variations. Thus the high salt structure of poly(d2NH2A-dT) remains a right-handed helix, likely under a dominant A conformation.


A molecular dynamics simulation of a polyamine-induced conformational change of DNA. A possible mechanism for the B to Z transition. A 75ps molecular dynamics simulation has been performed on a fully solvated complex of spermine with the B DNA decamer (dGdC)5.(dGdC)5. The simulation indicates a possible mechanism by which polyamines might induce the formation of a left-handed helix, the B to Z transition. Spermine was initially located in the major groove, hydrogen bonded to the helix. During the simulation the ligand migrates deeper into the DNA, maintaining strong hydrogen bonding to the central guanine bases and destroying the Watson-Crick base pairing with their respective cytosines. Significant rotation of these and other cytosine bases was observed, in part due to interactions of the helix with the aminopropyl chains of spermine. An intermediate BII conformation might be of importance in this process.


Groove width and depth of B-DNA structures depend on local variation in slide. The groove widths of DNA helix, especially minor groove width, are generally believed to be important for recognition of DNA by various types of ligands. It has been postulated earlier that large negative propeller twist, in the AT rich regions compresses the minor groove of duplex DNA. A systematic study has now been carried out by generating models with different values of local doublet and intra-basepair parameters and calculating their minor groove widths. It is found that several local doublet parameters affect the minor groove width but it depends most strongly on the local step parameters roll and slide when each parameter is considered individually. However, a detailed analysis of the various local parameters within the B-DNA family of crystal structures indicates that propeller twist and slide are most strongly correlated with the observed values of minor groove width. The groove depth is also strongly correlated with slide. Thus the local base sequence dependent variations in slide can modify both the groove width and depth and consequently determine the ligand binding properties of DNA.


Plasmon interpretation of 25 cm-1 mode in DNA. An extension of the effective field approach for the normal mode dynamics of dissolved DNA polymers has been applied to study the vibrational modes of DNA-hydration sheath-counterion system, to include the effect of site bound counterions on the system dynamics. An alternative interpretation has been suggested for a 25 cm-1 mode recently observed in DNA samples and interpreted earlier as an interhelical mode. Analysing the eigenvectors this mode is found to possess a large electric dipole moment with longitudinal collective oscillations of the system. These characteristics identify this mode as a collective plasmon mode. Possible physical reasons for the existence of this character have been presented.


Lipid conformational nomenclature: a general method. We propose a conformational nomenclature for amphiphilic lipid molecules that is general and compatible with the stereospecific numbering scheme, in contrast to earlier methods in which discrepancies with the sn-scheme lead to contradictory assignments of the absolute configuration of the system. The present method can be rationally extended to different classes of lipids, both natural and synthetic. It is simple and provides a convenient framework for conformational studies on widely varying classes of lipids.


Diffusion-enhanced energy transfer investigation of histone H5 in chromatin with a fluorescently-labelled antibody fragment Fab'. The location of chicken erythrocyte H5 histone relative to the axis the 30 nm chromatin fibre axis has been investigated by diffusion-enhanced energy transfer. In this investigation, a neutral lanthanide chelate as donor and a fluorescent probe specific to H5 as acceptor have been used. The acceptor probe consists of H5 antibody Fab' fragment, which has been labeled with 5-iodoacetamidofluorescein (5-IAF). Using H5 fragments we have shown by ELISA that the antibodies recognized the N- and C-terminal ends of this histone. A neutral chelate of terbium (TbHED3A) was chosen as a suitable donor for energy transfer with IAF-labelled Fab' (Fab'-IAF) bound to H5 in various chromatin structures. The ionic strength dependence of the energy transfer from TbHED3A to chromatin-bound Fab'-IAF was used to estimate the accessibility and the location of the Fab' in chromatin. The rate constants for energy transfer, obtained from the lifetimes of the TbHED3A excited state in presence and absence of acceptor, indicated a decrease in transfer efficiency upon increase of salt concentration from 5 to 80 mM NaCl. This can be correlated with the chromatin folding occurring in this ionic strength range and is consistent with the location of at least some of the N and C-termini of H5 within the condensed chromatin structure.


Transcription regulation by steroid hormones: a computer simulation study. Three-dimensional structures of complexes of 66 amino acid-DNA binding domains of human progesterone (hPR), estrogen (hER) and glucocorticoid (hGR) receptors (proteins), with ten base pair DNA duplexes: d(AGGTCATGCT).d(AGCATGACCT) and d(AGAACATGCT).d(AGCATGTTCT) were obtained using computer modeling and molecular mechanics techniques. Cartesian coordinates for the proteins were obtained from: 1) structural data of hER and hGR by NMR spectroscopy; 2) steric constraints imposed by tetrahedral coordination of the zinc ion to Cys residues, and 3) energy minimization in torsional and cartesian space. The proteins were made to interact with DNA (in B-form) in major groove through alpha-helical linker between the two zinc fingers. The geometry of the complexes was obtained by allowing them to slide, glide, penetrate in to and out of the groove, and to rotate about the helical axis. The complexes were energy minimized. Also maximized was the number of H-bonds between proteins and DNA. The complex structures were refined by molecular mechanics using AMBER 3.0. Structural parameters of DNA were analyzed in each complex and compared with those of native DNA optimized separately. The stereochemical differences of the complexes are discussed.


Using lambda exonuclease inhibition assays to map carcinogen binding sites. Previous restriction mapping studies (M.A. Mallamaci, D.P. Reed and S.A. Winkle, J. Biomolecular Structure and Dynamics, in press (1992)) have indicated that a small number of locations on the plasmid pBR322 may be high affinity binding sites for the carcinogen N-acetoxy-N-acetyl-2-aminofluorene (acetoxyAAF). PBR322 was reacted with acetoxyAAF to produce DNA with one, three or seven acetoxyAAF moieties per DNA molecule. Thus only the higher affinity binding sites are affected. Subsequent digestion with the restriction enzyme Hinf I produced fragments containing previously indicated locations of potential acetoxyAAF binding sites. Fragments thought not to contain binding sites were also examined as controls. The isolated fragments, singly 32P end-labeled, were digested with lambda exonuclease. The three fragments suspected of containing acetoxyAAF binding sites possess new lambda exonuclease inhibition sites when the fragments are obtained from acetoxyAAF reacted DNA. No such inhibition sites are found with the two fragments suggested previously not to contain acetoxyAAF binding sites. These carcinogen produced inhibition sites occur in sequences which are similar, suggesting that acetoxyAAF preferentially may target a small number of sequences.


Restriction enzyme mapping of carcinogen binding regions on pBR322. Previous equilibrium binding experiments (S.A. Winkle and T.R. Krugh, Nucleic Acids Res. 9, 3175-3186 (1981)) suggested that the carcinogen N-hydroxy-N-acetyl-2-aminofluorene might exhibit preferential binding to a small number of sites on phiX174 DNA. To examine whether the covalently binding analogue N-acetoxy-N-acetyl-2-aminofluorene (acetoxyAAF) also possesses high affinity sites, the plasmid pBR322 was reacted with 3H labeled acetoxyAAF to give one to sixteen adducts per DNA molecule. Thus only higher affinity sites would be affected. The DNA was subsequently cleaved with either Alu I, Hae III, Hha I, Hinf I or Hpa II restriction endonuclease and the restriction fragments isolated by gel electrophoresis. Examination of the distribution of 3H acetoxyAAF among the fragments was not random but, rather, with each enzyme, the acetoxyAAF was found predominantly in a few fragments. The locations of the bands containing the acetoxyAAF for each enzyme overlap--suggesting that there are regions on pBR 322 which contain high affinity sites for acetoxyAAF binding.


Conformation and dynamics of drug-DNA intercalation. Molecular dynamics simulations have been undertaken for a B-form dodecanucleotide duplex in solution with and without an intercalated proflavine molecule between the central C.G base pairs. The introduction of this simple intercalator affects both the conformational features and dynamic properties of the oligonucleotide double helix. Changes are seen in the rms atomic fluctuations and anisotropy of phosphate, sugar and base atoms. The backbone conformation is slightly changed on average and more sugars adopt the C3' endo conformation in the simulation of the complex compared with the simulation of the oligonucleotide alone. Both major and minor grooves becomes wider on average with the addition of the intercalating drug. Flanking A.T base pairs on both sides of the intercalation site have undergone an increase in flexibility, with the base pairs, especially at the 5' side, having the N1...N3 hydrogen bonds being broken.


Characteristics of labeling of the cerebellar Purkinje neuron by L7 antiserum. Previously, it has been shown by light microscopy that antiserum to the L7 protein labels cerebellar Purkinje neurons. Herein we show by light and electron microscopic immunocytochemistry that all cerebellar Purkinje cells express L7 and that the gene product is distributed to all neuronal compartments, including the nucleus. Possible functional roles for L7, based on its subcellular localization, are discussed. L7 is proposed as an excellent marker molecule for future studies of normal and aberrant cerebellar development.


The serotoninergic system of the brain of the lamprey, Lampetra fluviatilis: an evolutionary perspective. The distribution of serotonin(5HT)-immunoreactive cell bodies, nerve fibers and terminals was investigated by light microscopy in the lamprey Lampetra fluviatilis. Twenty-three distinct groups of 5HT neuronal somata were identified from diencephalic to rhombencephalic levels in the brain. The diencephalon contained a subependymal population of immunoreactive cells in contact with the cerebrospinal fluid (CSF), which could be subdivided into five separate groups situated in the hypothalamus and ventral thalamus; five additional groups of immunoreactive diencephalic neurons, situated in the dorsal thalamus and thalamo-pretectum, which were not in contact with the CSF, were also identified. In the midbrain, in addition to a few labelled neurons in the optic tectum, two structures containing immunoreactive cells were identified in the tegmentum mesencephali. None of these 5HT cells corresponded to the retinopetal neurons which are situated in the same region. A very large number of 5HT neurons were observed in the hindbrain which could be divided into seven groups in the isthmus rhombencephali and a further three in the rhombencephalon proper. Immunoreactive fibers and terminals were widely distributed throughout the neuraxis. In the telencephalon two 5HT fibers assemblies, lateral and medial, could be identified which terminated in both pallial and subpallial structures. The richest serotoninergic innervation in the telencephalon was found in the lateral portion of the primordium hippocampi and the medial part of the corpus striatum. In the diencephalon, the distribution of immunoreactive fibers and terminals was heterogeneous, being most pronounced in the lateral hypothalamic area and in the infundibulum. The densest arborization of fibers in the mesencephalon was found in the stratum fibrosum et cellulare externum of the optic tectum, a major site of retinal projection, and in the nucleus interpeduncularis mesencephali as well as in the oculomotor nuclei. The rhombencephalon is richly endowed with serotoninergic fibers and terminals, many labelled arborizations being found in the nuclei isthmi rhombencephali and around the nucleus motorius nervi trigemini. Comparative analysis of the serotoninergic systems of petromyzontiforms and gnathostomes indicates that the evolution of this system involves a progressive elimination of the rostral immunoreactive cells and an increasing complexity of the caudal population of serotoninergic neurons.


Lung adenoma development and NK activity in mice treated with multiple carcinogens. A wide-spectrum initiation model was investigated in mice. Sequential treatments with diethylnitrosamine, urethane and N-methylnitrosourea, with or without a promoter, phenobarbital, resulted in tumor formation in the lungs in 85-90% of animals, but did not produce any tumorous lesions in other organs. The lung tumors were adenomas and the mean number of adenomas was 2.2-2.6 per mouse. Phenobarbital combination had no additive effect on lung tumor incidence and multiplicity. Splenic NK cell activity showed inconsistent increment in the carcinogen plus phenobarbital-treated group during the experiment (P less than 0.05).


Technetium-99m HM-PAO SPECT in patients with delayed neurologic sequelae after carbon monoxide poisoning. We used single photon emission computed tomography (SPECT) with technetium-99m hexamethylpropylene amine oxime (99mTc-HM-PAO) in 14 studies on 6 patients with delayed neurologic sequelae from carbon monoxide (CO) poisoning to determine whether any changes in cerebral blood flow could be correlated with clinical or computed tomographic evidence of delayed deficits. Among the six initial CT brain scans, two showed low density of both basal ganglia and two showed decreased density of the cerebral white matter. There was no correlation between the clinical outcome and the findings of the follow-up CT brain scans. Of the two SPECTS with 99mTc-HM-PAO performed during acute anoxic insult, one showed focal hypoperfusion which appeared 20 days prior to the onset of delayed neurologic sequelae after CO poisoning. Seven SPECTs in the six patients performing the delayed phase showed diffuse patched patterns of hypoperfusion which improved on follow-up images. There was good correlation between the clinical outcome and the findings of the 99mTc-HM-PAO SPECT. In preliminary conclusion, 9Tc-HM-PAO brain SPECT can be used for predicting or evaluating the outcome of delayed neurologic sequelae after CO poisoning. Cerebral vascular changes may be the possible cause of hypoperfusion in patients with CO poisoning.


The distribution of cholinergic muscarinic receptors in the dog frontal lobe. The topographical distribution of cholinergic muscarinic receptor (MChR) sites was studied by means of quantitative receptor autoradiography using [3H]quinuclidinyl benzilate ([3H]QNB) in the frontal (prefrontal, premotor and motor) cortex of the dog. The mean binding value in the frontal cortex was 408 +/- 5.0 fmol/mg tissue and the only area that differed significantly from the mean was the primary motor cortex, where the binding value was significantly lower. In the dorsal part of the prefrontal and premotor cortical subregions studied, a tri-laminar pattern of [3H]QNB labelling was observed, with a superficial dense band of label corresponding to cortical layers I, II and III. The deep high density band overlaid layer V and the upper part of the layer VI. In the ventral part of the prefrontal cortex this pattern gradually disappeared and in the most ventral part no laminar differences were seen. In contrast, in primary motor areas, the deep band of labelling corresponding to layer V was much less pronounced than in the frontal association cortex. Variations in the distribution of MChR sites seem to reflect to some extent the greater cytoarchitectonic differentiation of the dorsal zone and also the similarity between the ventral zone and the limbic cortex described by us previously.


Autoradiographic distribution of [3H]nicotine binding in human cortex: relative abundance in subicular complex. Distinct patterns of [3H]nicotine (3 nM) binding were apparent in various regions of adult human neo- and archicortex. Receptor binding was greatest in the subicular complex--particularly presubiculum--and entorhinal cortex, where it was prominent in the characteristic parvo- and magnocellular islands of these regions and in middle layers of entorhinal cortex. In somatosensory cortex (Brodmann areas 3, 1 and 2) and occipital (area 17) cortex binding was highest in the upper and lower layers, and relatively sparse in the sensory input, layer IV. In primary motor (area 4) and temporal (area 21) cortex, binding in the outer half of the cortical ribbon was denser than that in the inner half and a distinct band was apparent in temporal and cingulate (area 32) in the lower portion of layer III. In prefrontal association cortex the pattern of binding was less distinct although slightly higher in the lower architectonic layers. There was generally little binding in the hippocampus (areas CA1-4) and dentate gyrus with the exception of the stratum lacunosum moleculare in CA2-3 and, to a lesser extent, supra- and subgranule zones of the dentate. These patterns of reactivity, which are distinct from that of the major cortical cholinergic innervation, suggest that the nicotinic receptor, detected using nanomolar concentrations of [3H]nicotine, may primarily be associated with intracortical circuitry in the neocortex. The relatively high density in entorhinal and subicular regions may be related to the extensive phylogenetic development of these regions which has occurred in conjunction with the development of multimodal association circuitry in the human cortex.


Variations of the ventral rami of the brachial plexus. We studied the variations in the ventral rami of 152 brachial plexuses in 77 Korean adults. Brachial plexus were composed mostly of the fifth, sixth, seventh and eighth cervical nerves and the first thoracic nerve (77.0%). In 21.7% of the cases examined, the fourth, fifth, sixth, seventh and eighth cervical and the first thoracic nerves contributed to the plexus. A plexus composed of the fourth, fifth, sixth, seventh and eighth cervical and the first and second thoracic nerves, and a plexus composed of the fifth, sixth, seventh eighth cervical nerves were also observed. The plexuses were classified into three groups according to cephalic limitation, and the plexus of group 2 in which the whole fifth cervical nerve enters the plexus, were observed the most frequent. The average diameter of the sixth and the seventh cervical ventral rami of the plexus was greatest and that of the fifth cervical was smallest. The largest nerve entering the plexus was the sixth or the seventh cervical nerve in about 79% of cases. The dorsal scapular nerve originated from the fifth cervical ventral ramus in 110 cases (75.8%). The long thoracic nerve was formed by joining of roots from the fifth, sixth, and seventh cervical nerves in 76.0% of cases. Also, a branch to the phrenic nerve, the suprascapular nerve, a nerve to the pectoralis major muscle and a nerve to the subscapular muscle arising from the ventral rami of the plexus were observed.


Anatomical observation on draining patterns of saphenous tributaries in Korean adults. This study was done to identify the normal and variants of saphenous tributaries in Korean adults. The pattern of confluence of saphenous tributaries, medial accessory saphenous, lateral accessory saphenous, superficial epigastric, superficial circumflex iliac and superficial external pudendal veins, was carefully examined in 249 lower limbs (right, 129; left, 120) of embalmed Korean cadavers (73 males & 56 females). The medial accessory saphenous vein drained into the great saphenous vein directly (in 82.3%) or by a common trunk (in 17.7%) with the superficial epigastric or superficial external pudendal vein. The lateral accessory saphenous vein entered the great saphenous (in 67.1%) or the femoral vein (in 32.9%) directly or, forming a common trunk with other saphenous tributaries. The superficial epigastric vein joined the great saphenous (in 77.1%) or the femoral vein (in 22.9%) directly or, by a common trunk with other saphenous tributaries. The superficial circumflex iliac vein reached the great saphenous (in 83.1%) or the femoral vein (in 16.9%) directly or, by a common trunk with other saphenous tributaries. The superficial external pudendal vein opened into the great saphenous (in 95.2%) or the femoral vein (in 4.8%) directly or by a common trunk with other saphenous tributaries. In Koreans, the incidence of the normal pattern of saphenous tributaries was 23.7% and in 76.3% any one of variant saphenous tributaries entered the femoral or the great saphenous vein by a common trunk with other saphenous tributaries.


Predictable ultrasonographic findings of early abortion. Early fetal growth delay and early oligohydramnios have been suspected as signs of embryonal jeopardy. However, little information is available for the prediction of early abortion. Sonographic examination of 111 early pregnancies between the sixth and ninth gestational week with regular, 28 day menstrual cycles was performed to investigate predictable sonographic findings of early abortion. Sonographic measurements of the gestational sac (G-SAC), crown-rump length (CRL) and fetal heart rate (FHR) were performed using a linear array real time transducer with Doppler. All measurements of 17 early abortions were compared to those of 94 normal pregnancies to investigate the objective rules for the screening of early abortion. Most of the early aborted pregnancies were classified correctly by discriminant analysis with G-SAC and CRL (G-SAC = 0.5222 CRL + 14.6673 = 0.5 CRL + 15, sensitivity 76.5% specificity 96.8%). With the addition of FHR, 94.1% of early abortions could be predicted. In conclusion, sonographic findings of early intrauterine growth retardation, early oligohydromnios and bradycardia can be predictable signs for the poor prognosis of early pregnancies.


Immunohistochemical study of the catecholaminergic innervation of the spinal cord of the rat using specific antibodies against dopamine and noradrenaline. We have assessed the relative contributions of dopaminergic and noradrenergic descending systems to the catecholaminergic innervation of the rat spinal cord. Fibres and terminals were labelled with their own neurotransmitter by using specific antibodies raised against dopamine (DA) and noradrenaline (NA) respectively. For this purpose, immunohistochemistry according to the peroxidase anti-peroxidase technique was performed in different experimental conditions. Two group of rats received intracisternal 6-hydroxy-dopamine (6-OHDA) injections either with or without benzatropine pretreatment. Animals of a third group were not pretreated at all. While 6-OHDA induced a complete disappearance of spinal NA-like immunoreactivity (NA-LI), except for scarce residual fibres in the thoracic intermedio-lateral cell column, DA-like immunoreactivity (DA-LI) was unaffected by the lesion. This strongly suggests that the antisera used specifically labelled NA-containing and DA-containing fibres respectively. Spinal DA-LI and NA-LI innervations differed markedly in their topographical distributions and in the morphology of the corresponding fibres. DA-LI innervation was restricted to laminae I, III and IV and to the intermediate zone, especially the autonomic areas. In the ventral horn, it was sparse and more visible after acidification of the fixation solution. NA-LI innervation was much more widely spread. In addition, the organization of NA-LI fibres suggests that the innervation of the whole dorsal horn comes from a group of fibres travelling, at least partially, in the superficial dorsal horn.


The effect of hyperglycemia on lipid peroxidation in the global cerebral ischemia of the rat. To investigate the influence of hyperglycemia on ischemic brain damage, we measured brain ATP, lactate and malondialdehyde (MDA) levels in global cerebral ischemic models of Wistar rats. We induced global cerebral ischemia by the 4-vessel occlusion method. After 30 or 60 min of occlusion, and after 30 min of reperfusion, we measured brain ATP, lactate and MDA levels. During the ischemic period, brain ATP levels decreased to 30-70% of sham groups both in normoglycemic and hyperglycemic groups. But during the reperfusion period, the recovery rate of ATP levels was significantly lower in the hyperglycemic than in the normoglycemic groups (p less than 0.05). After 60 min of global ischemia, brain lactate increased much more in the hyperglycemic than in the normoglycemic group, and, during reperfusion, was washed out slowly in the hyperglycemic group. The MDA level, a parameter of lipid peroxidation, increased more in the hyperglycemic group than in the normoglycemic group during reperfusion periods (p less than 0.05). We conclude that hyperglycemia increases lactate accumulation, delays the recovery of energy metabolism, and enhances the lipid peroxidation in the transient global ischemia of rat brain. These findings may suggest the harmfulness of hyperglycemia in clinical cerebral ischemia.


Adrenergic projections from the lower brainstem to the hypothalamic paraventricular nucleus, the lateral hypothalamic area and the central nucleus of the amygdala in rats. Fine networks of phenylethanolamine N-methyltransferase (PNMT)-immunoreactive fibers are found in the hypothalamic paraventricular nucleus--mainly in the anterior, dorsal and dorso-medial parvicellular subdivisions, the lateral hypothalamus (dorsal, lateral and ventral to the fornix) and in the central amygdaloid nucleus. Coronal hemisections of the brainstem through the rostral level of the medulla oblongata show that most hypothalamic and amygdaloid PNMT fibers arise from the medullary adrenergic cell groups. Fourteen, but not 10 days after total hemisections, PNMT fibers disappeared almost completely from the hypothalamus and amygdala, ipsilateral to the knife cuts. A small decrease was also observed in the ventral, lateral hypothalamus on the contralateral side. Partial depletion of PNMT-immunoreactivity in the hypothalamus and the amygdala after medial or lateral brainstem hemisections indicates that ascending PNMT-immunoreactive fibers pass through mainly the lateral portion of the medulla, but some fibers also in its medial portion. Midsagittal transection of the diencephalon slightly reduced PNMT immunostaining in the paraventricular nucleus and the lateral hypothalamus bilaterally. The results show that the ascending PNMT system essentially is ipsilateral, but probably with a small crossing-over component, both at the diencephalic and lower brainstem level.


Small-sized acute subdural hematoma: operate or not. A retrospective study of 90 cases of small-sized (less than 3 mm on the printed CT film) acute (within 24 hours) subdural hematoma (SASDH) is presented. From March 1985 to December 1986, the SASDH were immediately operated on (operation rate: 86.0%). From January 1988 to December 1989, we attempted to treat them conservatively (operation rate: 49.1%). The patient population for this study consisted of 38 surgically-treated patients in the first period (Group I), 26 surgically-treated patients in the second period (Group IIs), and 26 conservatively-treated patients in the second period (Group IIc). We compared the clinical features, radiologic findings, and outcome of these 3 groups. The clinical features of Group I, including age, sex, Glasgow Coma Scale (GCS) score on admission, pupillary status on arrival, and interval from injury to the CT, did not differ significantly from those of Group II (P greater than 0.01). The only difference was the timing of the operation. In Group I, 20 patients (52.6%) received an operation within 4 hours, while in Group IIs, only 7 patients (26.9%) underwent surgery within 4 hours (P less than 0.05). The radiologic findings of Group I, including the thickness and volume of the hematoma, the degree of midline shift, and the frequency of skull fracture, also did not differ from those of Group II (P greater than 0.1). However, the outcome of Group II strikingly differed from that of Group I. The mortality rate was 76.3% in Group I, while it was 44.2% in Group II (P less than 0.005).(ABSTRACT TRUNCATED AT 250 WORDS)


Ossifying fibroma of the sella turcica.

Ossifying fibroma of the sella turcica. Ossifying fibroma of the sellar turcica is extremely rare. There are only sporadic case reports in the literature. One such case simulating pituitary adenoma is presented in an 18-year-old girl.


Arterial oxygen desaturation rate following obstructive apnea in parturients. This study was attempted to observe the rate of oxygen desaturation after full oxygenation in six parturients scheduled for Cesarean sections and six patients scheduled for transabdominal hysterectomies. We calculated the mean rate of fall of arterial saturation (slope of desaturation: less than SaO2 (t2)-SaO2(t1) greater than/t2-t1) and changes in arterial blood gases were observed. All subjects were denitrogenated then a single isolated apnea was carried out. The mean time to obtain 90% saturation was longer in the nonpregnant group (7.5 min vs 3.6 min in parturients). The mean slope of desaturation was steeper in the parturients (-3.34) than the nonpregnant group (-1.52). As far as the oxygen reserve is concerned, the parturients had a lesser margin of safety than the nonpregnant women. It was concluded that the lower the thoracic gas volume (parturients), the lower the alveolar O2 stores and, the more rapidly these stores are depleted.


Portal and superior mesenteric venous gas with retroperitoneal abscess--CT diagnosis (case report). We present a case of portal and superior mesenteric venous gas in a 31-year-old diabetic woman with a left-sided retroperitoneal abscess. Five years prior to admission, patient was diagnosed with diabetes mellitus and developed emphysematous pyelonephritis, requiring nephrectomy on the left side. A CT examination showed air distributed throughout the portal venous system and superior mesenteric vein.


Thrombotic thrombocytopenic purpura-like syndrome associated with systemic lupus erythematosus--combined treatment with plasmapheresis and fresh frozen plasma infusion. We report on a patient with systemic lupus erythematosus, who, during the course of the illness, developed thrombotic thrombocytopenic purpura. In this case, the coexistence of these two conditions was confirmed by laboratory and pathologic findings. The infusion of fresh frozen plasma with plasmapheresis reversed the course of thrombotic thrombocytopenic purpura.


Glucose-6-phosphate dehydrogenase deficiency--report of 4 cases. Glucose-6-phosphate dehydrogenase (G6PD) deficiency is the most common hereditary enzyme disorder and more than 200 million people have a deficiency in this enzyme. It is a globally important cause of neonatal jaundice and causes life-threatening hemolytic crisis in childhood. At later ages, certain drugs such as antimalarials, and fava beans cause hemolysis among G6PD deficiency patients. The frequency and severity is influenced by genetic and cultural factors. It is common in Mediterranean, African, and some East Asian populations but rare in Korea. Four cases of G6PD deficiency which were first noticed in Korea are investigated with their clinical features.


Localized form of colitis cystica profunda--a case of occurrence in the descending colon. An unusual localization of localized colitis cystica profunda in a 31-year-old man is described. The patient presented as anal bleeding and a protruding mass at the descending colon; the mass was polypoid and was made up of papillary epithelial hyperplasia with downward herniation of glands into the submucosa. Only one similar case involving a descending colon has been reported in the world literature.


Nerve sheath myxoma (neurothekeoma)--a case report. A case of nerve sheath myxoma also called as neurothekeoma in a 33-year-old woman is described. The lesion appeared as a painful, elevated nodule on the scalp for several months, without an appreciable increase in size. Microscopically, it showed typical histologic characteristics of nerve sheath myxoma, and tumor cells revealed strong, positive reaction for S-100 protein and negativity for epithelial membrane antigen (EMA) on immunohistochemical staining. These immunohistochemical findings of this case support the view that the origin cells of this tumor may be schwann cells rather than perineurial cells. The histogenesis and differential diagnosis of this tumor are discussed.


POEMS syndrome--a case report.

POEMS syndrome--a case report. POEMS syndrome is a multisystem disorder associated with polyneuropathy, organomegaly, endocrinopathy, a monoclonal protein (M-protein), and skin changes. The authors describe a patient with POEMS syndrome who had osteosclerotic myeloma confirmed by open bone biopsy. Magnetic resonance imaging (MRI) showed discrete lesions of low signal intensity in both T1 and T2-weighted images. This patient is now being successfully treated with melphalan and prednisone with much improvement in skin thickening and sensory change in the lower extremities.


A technique to estimate the apparent surface pressure of emulsion particles using apolipoproteins as probes. The apparent pressures in the surface monolayer of emulsion particles can be estimated by comparing the absorption of an apolipoprotein to planar lipid monolayers and to emulsions. Lipids are spread at an air-water interface in a Pockels/Langmuir surface balance and the adsorption of [14C]-labeled apolipoproteins placed in the subphase is studied as a function of surface pressure using the surface radioactivity method. An apoprotein surface concentration/initial lipid surface pressure curve (gamma/pi i) is constructed. The maximum apolipoprotein surface concentration gamma e of emulsions is derived from standard emulsion/apolipoprotein binding isotherms. The apparent emulsion surface pressure is then estimated by comparing gamma e to the gamma/pi i curve. Apolipoprotein A-I has been used as an example of a probe to estimate the effective surface pressure in approximately 1000 A diameter egg yolk phosphatidylcholine/cholesterol/triolein emulsion particles. When the cholesterol content of emulsions is low, the surface pressure of the emulsion is about 17 dyne cm-1. At high cholesterol concentrations (0.49 cholesterol/phospholipid mole ratio) the surface pressure is increased to 25 dyne cm-1. The addition of the maximum amounts of apoA-I to these particles raises the effective surface pressure of the emulsion to about 30 dyne cm-1 and stabilizes the particles.


Carbon monoxide exposure of subjects with documented cardiac arrhythmias. The impact of low-level carbon monoxide exposure on ventricular arrhythmia frequency in patients with ischemic heart disease has not been thoroughly studied. The issue is of concern because of the potential proarrhythmic effect of carbon monoxide in patients with ischemic heart disease. We studied 30 subjects with well-documented coronary artery disease who had an average of at least 30 ventricular ectopic beats per hour over a 20-hour monitoring interval. By using appropriate inclusion and exclusion criteria, subjects were selected and enrolled in a randomized double-blind study to determine the effects of carbon monoxide exposure on ventricular arrhythmia frequency at rest, during exercise, and during ambulatory activities. The carbon monoxide exposure was designed to result in 3% or 5% carboxyhemoglobin levels, as measured by gas chromatography. The carbon monoxide exposure protocol produced target levels in 60 minutes, and the levels were maintained for an additional 90 minutes to provide adequate time to assess the impact of carbon monoxide on the frequency of ventricular ectopic beats. The data on total and repetitive ventricular arrhythmias were analyzed for seven specific time intervals: (1) two hours before carbon monoxide exposure; (2) during the two-hour carbon monoxide or air exposure; (3) during a two-hour rest period; (4) during an exercise period; (5) during an exercise recovery period; (6) six hours after carbon monoxide or air exposure; and (7) approximately 10 hours after exposure, or the remaining recording interval on the Holter monitor. There was no increase in ventricular arrhythmia frequency after carbon monoxide exposure, regardless of the level of carboxyhemoglobin or the type of activity. During steady-state conditions at rest, the number of ventricular ectopic beats per hour was 115 +/- 153 (SD) for room air exposure (0.7% carboxyhemoglobin), 121 +/- 171 for the lower carbon monoxide exposure (3.2% carboxyhemoglobin), and 94 +/- 129 for the higher carbon monoxide exposure (5.1% carboxyhemoglobin). The frequency of complex ventricular ectopy was not altered at the levels of carbon monoxide studied. Secondary analysis of the impact of carbon monoxide on ventricular ectopic beat frequency stratified by baseline ejection fraction, baseline ventricular ectopic beat frequency, and exercise-induced ST-segment changes did not indicate an effect of carbon monoxide on ventricular arrhythmias. In conclusion, low levels of carbon monoxide exposure resulting in blood levels of 3.2% and 5.1% carboxyhemoglobin, as measured by gas chromatography, do not have a proarrhythmic effect on patients with coronary artery disease and frequent ventricular ectopy.(ABSTRACT TRUNCATED AT 400 WORDS)


Nonlamellar phases formed by membrane lipids. A brief review of membrane lipids forming cubic and reversed hexagonal phases is presented. An emphasis is made on anionic lipids and particular microbial lipids.


The HIV-1 nef gene product is associated with phosphorylation of a 46 kD cellular protein. To study the biochemical properties of the HIV-1 nef gene product. Earlier reports suggested that Nef protein is phosphorylated and has kinase activity. These properties were examined using an in vitro translated product. A DNA fragment encoding Nef of HIV-1SF2 was transcribed in vitro under the control of T7 promoter. The generated nef messenger RNA (mRNA) was translated using a rabbit reticulocyte lysate system. Immunoprecipitation was performed with a specific monoclonal antibody to Nef. Kinase activity of the translated product was evaluated using [gamma-32P]GTP and ATP. Translated nef mRNA was found to encode a major protein of 27 kD with two other products, of 25 and 29 kD. Using Nef immune complexes for the kinase reaction, a protein of 46 kD that reacted with the anti-Nef monoclonal antibody was found to be strongly phosphorylated in the presence of Nef. This Nef-associated kinase activity on a p46 cellular substrate was dependent on ATP. The in vitro-translated nef gene product was found to be associated with phosphorylation of a p46 cellular protein present in rabbit reticulocyte lysate. The Nef protein has been linked to suppression of the replication of certain HIV strains. Identification of cellular targets of Nef activity could help to elucidate the mechanisms for this antiviral effect.


Expression of activation antigens, HLA-DR and CD38, on CD8 lymphocytes during HIV-1 infection. To study the expression of the activation markers human leukocyte antigen (HLA)-DR and CD38 antigen on CD8+ T-lymphocytes in HIV-infected subjects and HIV-negative controls. Two- and three-colour flow-cytometric analysis. Fresh peripheral venous blood was obtained from 16 HIV-infected subjects, representing four different stages of HIV disease, and from six HIV-negative controls. Three-colour lymphocyte immunophenotyping was performed using peridinyl chlorophyll-A protein (PerCP)-conjugated anti-CD8 monoclonal antibody (MAb) in combination with anti-HLA-DR (phycoerythrin) and anti-CD38 (fluorescein isothiocyanate) MAb. The relative percentage of the lymphocyte populations thus defined differed between HIV-negative and HIV-positive subjects and between HIV-infected subjects at different clinical stages of disease. Simultaneous expression of HLA-DR and CD38 within the CD8 T-lymphocyte compartment increased from 8% in controls to 49% in asymptomatic HIV-infected subjects (P less than 0.005). Symptomatic patients differed from asymptomatic seropositives by a further increase in the HLA-DR+ CD38+ CD8 subset. In AIDS patients, the HLA-DR+ CD38- CD8 subset decreased (P less than 0.05) and the HLA-DR- CD38+ CD8 subset increased (P less than 0.05), compared with the other HIV disease stage patients. There is a stage-associated pattern of HLA-DR and CD38 expression on CD8 T-lymphocytes during HIV infection; specific phenotypic patterns may have functional correlates in the host response to the virus.


Development of HIV-1 group-specific neutralizing antibodies after seroconversion. To study the induction of group-specific (gs) neutralizing antibodies to HIV-1 after seroconversion. Serum samples taken sequentially from seven Dutch homosexual men and four British haemophiliacs (anonymous sample, therefore sex not known) before and after seroconversion were tested for neutralizing antibodies effective against five diverse HIV-1 strains. Strains of HIV-1 tested included isolates from the United States, Europe and Africa. The gs neutralizing antibody response varied between individuals. Only five of the 11 individuals studied produced detectable neutralizing antibodies to laboratory-adapted HIV-1 strains (for example, IIIB) within 32 weeks of seroconversion. Most individuals initially produced antibodies effective against US/European isolates; the response then generally broadened to include the more diverse strains, i.e., African. These results suggest that the gs neutralizing target for HIV-1 is poorly immunogenic in vivo and is probably not highly conserved among diverse HIV-1 strains.


Glutathione depletion in HIV-infected patients: role of cysteine deficiency and effect of oral N-acetylcysteine. To determine whether a single oral dose of N-acetylcysteine corrects the deficiency of cysteine and glutathione in plasma and mononuclear cells of HIV-infected patients. Pharmacokinetic and pharmacodynamic study. Cysteine and glutathione were measured in plasma and peripheral blood mononuclear cells of patients at different stages of HIV infection before and after a single oral dose of N-acetylcysteine. At baseline, the plasma concentrations of glutathione and cysteine were significantly lower in HIV-infected patients than in healthy controls. The intracellular concentration of glutathione correlated with the absolute CD4 lymphocyte counts: the concentration of glutathione in mononuclear cells was significantly lower in patients with more advanced immunodeficiency. A single oral dose of N-acetylcysteine increased the concentration of cysteine in plasma and mononuclear cells of HIV-infected patients. Four hours after N-acetylcysteine administration, intracellular glutathione concentrations in the patients were moderately higher than at baseline and at 2 h. Oral N-acetylcysteine transiently increases the concentrations of cysteine and glutathione in mononuclear cells of patients with HIV infection. A sustained increase in intracellular cysteine may be necessary to normalize intracellular glutathione. This may be accomplished by repeat administration of N-acetylcysteine.


The effect of treatment with zidovudine with or without acyclovir on HIV p24 antigenaemia in patients with AIDS or AIDS-related complex. To evaluate changes in serum HIV p24-antigen levels in a subset of patients who participated in a European/Australian double-blind, placebo-controlled trial evaluating the efficacy of zidovudine (250 mg every 6 h) alone or in combination with acyclovir (800 mg every 6 h) in patients with AIDS, AIDS-related complex (ARC) or Kaposi's sarcoma (KS). Double-blind, placebo-controlled randomized clinical trial of less than or equal to 6 months' therapy. Samples were obtained from patients attending teaching hospital outpatient clinics in seven European countries and Australia. One hundred and ninety-seven HIV-infected patients (60 with AIDS and 137 with ARC or KS). Serum HIV p24-antigen levels measured using the Abbott HIV solid-phase enzyme immunoassay. Of 76 ARC/KS patients who were initially HIV p24-antigen-positive, one out of 25 randomized to placebo, eight out of 23 to zidovudine and 11 out of 28 to the zidovudine/acyclovir combination became antigen-negative. The proportion of patients who became antigen-negative was significantly higher in both the zidovudine group (P = 0.016) and the zidovudine/acyclovir group (P = 0.004), compared with the placebo group. There were no statistical differences between the zidovudine and the zidovudine/acyclovir groups. During the trial p24-antigen levels in the zidovudine-treated patients reached their minimum after 4-8 weeks of therapy, and tended to increase gradually thereafter. Disease progression occurred irrespective of whether p24-antigen levels declined during therapy. No association between p24-antigen responses to therapy and baseline disease stage, Karnofsky score or baseline CD4 cell count was detectable. Acyclovir does not potentiate the effect of zidovudine on p24-antigen levels. Change in antigen level in response to antiviral therapy needs further investigation before it is used as a surrogate marker for clinical efficacy of antiviral therapy.


Pharmacokinetics of zidovudine in end-stage renal disease: influence of haemodialysis. To study the pharmacokinetics of zidovudine (ZDV) and its glucoronide metabolite (G-ZDV) in a patient with end-stage renal disease in haemodialysis. Pharmacokinetics study performed during and between haemodialysis sessions. The patient was treated with oral ZDV (100 mg every 8 h). Concentrations of ZDV and G-ZDV were measured by radioimmunoassay. A monocompartmental model was used to calculate pharmacokinetic parameters. The peak plasma concentrations of ZDV and G-ZDV after drug administration between haemodialysis sessions were 0.57 and 10.01 micrograms/ml, respectively. The half-lives of ZDV and G-ZDV rose to 3.2 and 14.2 h, respectively. The total body clearance for ZDV in the period between haemodialysis sessions (0.44 l/kg/h) was 66% lower than normal values. The ZDV half-life was normalized by haemodialysis, the total body clearance of ZDV increased (1.12 l/kg/h) and the G-ZDV half-life shortened (5.9-7.9 h). Neither G-ZDV accumulation nor derived ZDV toxicity occurred. Our data suggest that ZDV is safe and an efficient drug when administered at a dosage of 100 mg three times daily in patients with end-stage renal disease in haemodialysis sessions, and that ZDV and G-ZDV are cleared by haemodialysis.


Pancreatitis and pancreatic dysfunction in patients taking dideoxyinosine. To describe the incidence, clinical characteristics and dose relationship of dideoxyinosine (ddI)-associated pancreatitis. Patients enrolled in a Phase I dose escalation trial of ddI [AIDS Clinical Trials Group (ACTG) 064] were evaluated for signs and symptoms of pancreatic dysfunction. Two ACTG sites. Forty-four patients with AIDS or AIDS-related complex (ARC) and a CD4 cell count less than or equal to 400 x 10(6)/l. Seven patients developed pancreatitis that lasted from 1 to 7 weeks and varied in severity from mild to life-threatening. Seven other patients had evidence of hyperamylasemia or hypertriglyceridemia. Six patients who developed pancreatitis were able to tolerate rechallenge with lower doses of ddI. Development of pancreatitis correlated with cumulative dose of ddI but not with stage of disease or concomitant medications. Cumulative dose was not significantly associated with development of hyperamylasemia or hypertriglyceridemia in patients without clinical pancreatitis. The development of pancreatitis in AIDS or ARC patients receiving ddI varies in severity and time course and is associated with cumulative dose. Patients who develop pancreatitis may be able to tolerate therapy with a lower dose after resolution of their symptoms. Patients receiving ddI require careful monitoring for the development of this complication.


Progressive multifocal leukoencephalopathy in HIV-1-infected children. To describe the clinical and pathologic features of two HIV-1-infected children with progressive multifocal leukoencephalopathy (PML). Case report. University-affiliated, public-health trust hospital. Two HIV-1-infected children with PML are described. A 13-year-old girl, presumed to be congenitally infected with HIV-1, presented with dysarthria and paresthesias of the tongue and chin that evolved rapidly to dementia, muteness and severe spastic quadriparesis. The other patient, a 10-year-old boy who developed HIV-1 infection from a blood transfusion at the age of 3 years, presented with a facial palsy with subsequent development of right hemiparesis and aphasia. Brain biopsy in the first child and autopsy in the second confirmed the diagnosis of PML. In both patients, the CD4 T-lymphocyte count was less than 100 x 10(6)l at the time of neurological presentation. Despite seroepidemiological studies suggesting that the majority of individuals are infected with JC virus during childhood, PML is rare in children with impaired cell-mediated immunity. Our patients illustrate that PML is among the neurological complications of HIV-1 infection in children.


The spectrum of HIV-1-related disease among outpatients in New York City. To define the spectrum of HIV-1-related disease in New York City (NYC) and to determine how the clinical spectrum of illness differs in various populations. The medical records of the 2983 HIV-infected individuals who had received care through 1989 at four hospital outpatient clinics and two private physicians' offices were reviewed retrospectively. Sixty-one per cent of the study patients and 48% of patients seen in 1989 had AIDS. HIV-infected women were significantly less likely to have AIDS and CD4 lymphocyte counts less than 200 x 10(6)/l than men. For every 100 AIDS patients seen in 1989, there were 88 non-AIDS patients with CD4 counts less than 500 x 10(6)/l, of whom 41 had CD4 counts less than 200 x 10(6)/l; thus, in addition to an estimated 16,425 individuals living with AIDS in NYC, we estimate that there are at least 14,454 HIV-infected individuals without AIDS with CD4 counts less than 500 x 10(6)/l, of whom 6734 have CD4 counts less than 200 x 10(6)/l. Men who have sex with men were significantly more likely to have Kaposi's sarcoma, cytomegalovirus disease and retinitis, cryptosporidiosis and lymphoma, and significantly less likely to have Pneumocystis carinii pneumonia, esophageal candidiasis, extrapulmonary tuberculosis (TB) and bacterial pneumonia than intravenous drug users. Whites were significantly less likely to have pulmonary TB than Hispanics, non-Haitian and Haitian blacks, toxoplasmosis than Hispanics and Haitian blacks, and salmonella septicemia than non-Haitian blacks. The frequencies of most diagnoses did not differ by sex; gynecologic diseases were recorded infrequently in the medical records of women in this study. These data indicate that there are more than 30,000 HIV-infected adults living in NYC with significant immunosuppression, that an increasing proportion of AIDS cases in NYC will occur among women, and that the spectrum of HIV-related disease varies markedly in different populations.


Maintenance of behavioral change in a cohort of homosexually active men. To assess associations of perceptions of sexual behavior change with actual risk behaviors and psychosocial variables, and to determine whether perceptions of behavior change predict subsequent behavior. Cohort study of homosexually active men. Community health center in Boston, Massachusetts, USA. Two hundred and sixty-two cohort members who participated in follow-up in 1989 and who had at least one subsequent visit. None. Composite risk behavior variable, based on unprotected anogenital contact and number of partners. Of the 96% who had effected behavior change, 47% perceived that they were able to maintain those changes consistently and 58% wanted to make more changes. Perceptions of consistent maintenance were associated with lower risk behavior, lower perceived riskiness of behaviors and susceptibility to AIDS, and fewer barriers to behavior change. Desire for more change was associated with increased behavioral effort, fewer barriers to condom use, and greater perceived riskiness of current behavior. Among those with lower risk behaviors, perceived inconsistent maintenance predicted relapse to more risky behavior at the following visit. Perceived maintenance of behavior change is potentially useful in identifying individuals at risk of relapse from safer sex.


HIV prevalence, attitudes and behaviour in clients of a confidential HIV testing and counselling centre in Uganda. To describe clients, operation and impact of an African public HIV testing and counselling centre. Analysis of samples from clients attending the AIDS Information Centre (AIC) in Kampala, Uganda in early 1991. HIV-1-positive and HIV-negative consecutive clients (250 of each), 86 consecutive couples, and 200 consecutive clients who were HIV-negative in 1990 and were attending for their repeat test. HIV seroprevalence rates, attitudes, behaviour and behaviour change. HIV-1 prevalence was 28% overall, 24% in men and 35% in women. Reasons for taking the HIV test were a planned marriage or a new relationship (27%; 84% in couples), to plan for the future (35%), distrust of sexual partner (14%) and illness or disease/death (not HIV-specific) of partner (20%). The majority of the reported intentions in response to a positive or a negative HIV test result were positive, demonstrating the ability to cope with this information. Of repeat clients, two (1%) had become HIV-1-positive. The majority of repeat clients reported one sexual partner only (67%) or sexual abstinence (25%). Compared with pre-test information from AIC clients attending for the first time, repeat clients reported casual sexual contacts less often (6 versus 25%) and, of those, the majority used condoms. Our study demonstrates the demand for and the feasibility of confidential HIV testing and counseling services in Uganda, and illustrates the value of these services in achieving behaviour changes. Such services should be considered an additional approach for the reduction of HIV transmission in Africa, especially in areas with high HIV seroprevalence rates.