Identification of driver genes for critical forms of COVID-19 in a deeply phenotyped young patient cohort

[Figure: see text].

NCKAP1L defects lead to a novel syndrome combining immunodeficiency, lymphoproliferation, and hyperinflammation

The Nck-associated protein 1–like (NCKAP1L) gene, alternatively called hematopoietic protein 1 (HEM-1), encodes a hematopoietic lineage–specific regulator of the actin cytoskeleton. Nckap1l-deficient mice have anomalies in lymphocyte development, phagocytosis, and neutrophil migration. Here we report, for the first time, NCKAP1L deficiency cases in humans. In two unrelated patients of Middle Eastern origin, recessive mutations in NCKAP1L abolishing protein expression led to immunodeficiency, lymphoproliferation, and hyperinflammation with features of hemophagocytic lymphohistiocytosis. Immunophenotyping showed an inverted CD4/CD8 ratio with a major shift of both CD4⁺ and CD8⁺ cells toward memory compartments, in line with combined RNA-seq/proteomics analyses revealing a T cell exhaustion signature. Consistent with the core function of NCKAP1L in the reorganization of the actin cytoskeleton, patients’ T cells displayed impaired early activation, immune synapse morphology, and leading edge formation. Moreover, knockdown of nckap1l in zebrafish led to defects in neutrophil migration. Hence, NCKAP1L mutations lead to broad immune dysregulation in humans, which could be classified within actinopathies.

Delirium and encephalopathy in severe COVID-19: a cohort analysis of ICU patients

BACKGROUND

Neurotropism of SARS-CoV-2 and its neurological manifestations have now been confirmed. We aimed at describing delirium and neurological symptoms of COVID-19 in ICU patients.

METHODS

We conducted a bicentric cohort study in two French ICUs of Strasbourg University Hospital. All the 150 patients referred for acute respiratory distress syndrome due to SARS-CoV-2 between March 3 and May 5, 2020, were included at their admission. Ten patients (6.7%) were excluded because they remained under neuromuscular blockers during their entire ICU stay. Neurological examination, including CAM-ICU, and cerebrospinal fluid analysis, electroencephalography, and magnetic resonance imaging (MRI) were performed in some of the patients with delirium and/or abnormal neurological examination. The primary endpoint was to describe the incidence of delirium and/or abnormal neurological examination. The secondary endpoints were to describe the characteristics of delirium, to compare the duration of invasive mechanical ventilation and ICU length of stay in patients with and without delirium and/or abnormal neurological symptoms.

RESULTS

The 140 patients were aged in median of 62 [IQR 52; 70] years old, with a median SAPSII of 49 [IQR 37; 64] points. Neurological examination was normal in 22 patients (15.7%). One hundred eighteen patients (84.3%) developed a delirium with a combination of acute attention, awareness, and cognition disturbances. Eighty-eight patients (69.3%) presented an unexpected state of agitation despite high infusion rates of sedative treatments and neuroleptics, and 89 (63.6%) patients had corticospinal tract signs. Brain MRI performed in 28 patients demonstrated enhancement of subarachnoid spaces in 17/28 patients (60.7%), intraparenchymal, predominantly white matter abnormalities in 8 patients, and perfusion abnormalities in 17/26 patients (65.4%). The 42 electroencephalograms mostly revealed unspecific abnormalities or diffuse, especially bifrontal, slow activity. Cerebrospinal fluid examination revealed inflammatory disturbances in 18/28 patients, including oligoclonal bands with mirror pattern and elevated IL-6. The CSF RT-PCR SARS-CoV-2 was positive in one patient. The delirium/neurological symptoms in COVID-19 patients were responsible for longer mechanical ventilation compared to the patients without delirium/neurological symptoms. Delirium/neurological symptoms could be secondary to systemic inflammatory reaction to SARS-CoV-2.

CONCLUSIONS AND RELEVANCE

Delirium/neurological symptoms in COVID-19 patients are a major issue in ICUs, especially in the context of insufficient human and material resources.

TRIAL REGISTRATION

NA.

FACS - based isolation of human eosinophils allows purification of high quality RNA

Here we extensively describe a FACS-based protocol for isolating intact non-stained human eosinophils from peripheral blood; a stop forward from our recently published initial study. This method of purification could be accomplished in <3 h with only small volumes of whole blood necessary, even in healthy subjects generally exhibiting low levels of circulating eosinophils. Eosinophil activation during the isolation steps appeared to be minimal and this purification procedure yielded high quality RNA. Moreover, these FACS-isolated eosinophils had prolonged viability in culture and were suitable for further activation assays.

Mutations in signal recognition particle SRP54 cause syndromic neutropenia with Shwachman-Diamond-like features

Shwachman-Diamond syndrome (SDS) (OMIM #260400) is a rare inherited bone marrow failure syndrome (IBMFS) that is primarily characterized by neutropenia and exocrine pancreatic insufficiency. Seventy-five to ninety percent of patients have compound heterozygous loss-of-function mutations in the Shwachman-Bodian-Diamond syndrome (sbds) gene. Using trio whole-exome sequencing (WES) in an sbds-negative SDS family and candidate gene sequencing in additional SBDS-negative SDS cases or molecularly undiagnosed IBMFS cases, we identified 3 independent patients, each of whom carried a de novo missense variant in srp54 (encoding signal recognition particle 54 kDa). These 3 patients shared congenital neutropenia linked with various other SDS phenotypes. 3D protein modeling revealed that the 3 variants affect highly conserved amino acids within the GTPase domain of the protein that are critical for GTP and receptor binding. Indeed, we observed that the GTPase activity of the mutated proteins was impaired. The level of SRP54 mRNA in the bone marrow was 3.6-fold lower in patients with SRP54-mutations than in healthy controls. Profound reductions in neutrophil counts and chemotaxis as well as a diminished exocrine pancreas size in a SRP54-knockdown zebrafish model faithfully recapitulated the human phenotype. In conclusion, autosomal dominant mutations in SRP54, a key member of the cotranslation protein-targeting pathway, lead to syndromic neutropenia with a Shwachman-Diamond-like phenotype.

Polymorphisms in EGFR and IL28B are associated with spontaneous clearance in an HCV-infected Iranian population

Although most hepatitis C virus (HCV)-infected individuals develop chronic infection, about 25% of them are able to clear the virus spontaneously without any therapeutic intervention. The aim of the present study was to identify genes associated with spontaneous HCV clearance in a population of Iranian patients. We genotyped 110 single-nucleotide polymorphisms (SNPs) in 59 selected--candidate--genes in a cohort of 107 HCV-infected participants who spontaneously cleared the infection and 176 participants whose infection persisted. Three out of the 110 SNPs were found to be associated with HCV outcome (P-values<0.03). rs11506105 in EGFR (epidermal growth factor receptor gene), and rs11881222 and rs12979860 in IL28B (interferon-λ3 gene). Multivariate logistic regression of the three markers showed that the A/A genotypes in both rs11506105 (EFGR) and rs11881222 (IL28B), and the C/C genotype in rs12979860 (IL28B) are associated with HCV clearance (recessive model: odds ratio (OR)=2.06, 95% confidence interval (95% CI)=1.09-3.88, P=0.025; OR=2.09, 95% CI=1.23-3.60, P=0.007; and OR=1.95, 95% CI=1.15-3.35, P=0.014 for rs11506105, rs12979860 and rs11881222, respectively). In conclusion, EGFR and IL28B SNPs are strong independent predictive markers of spontaneous viral clearance.

On the genetics of the Silk Route: association analysis of HLA, IL10, and IL23R-IL12RB2 regions with Behçet's disease in an Iranian population

Despite that the association of Behçet's disease (BD) with the HLA-B5 was first established in the 1970s, a number of recent genome-wide association studies have both confirmed and furthered this association--in various populations--to individual SNPs both inside and outside the HLA. The former include HLA-B, MICA, and HLA-A, while the latter encompass IL10 and IL23R-IL12RB2 regions. The present study examined whether some of these SNPs could be replicated in an Iranian population, where the prevalence of disease is amply documented. Eight SNPs were selected and tested in 552 patients and 417 controls. These were rs7539328, rs12119179, rs1495965, rs1518111, and rs1800871 in IL10 and IL23R-IL12RB2 regions and rs114854070, rs12525170, and rs76546355 (formerly rs116799036) in the HLA locus. The well-known BD-associated genes HLA-B and MICA were independently genotyped. Although we were not able to formally replicate the association with IL10 and IL23R-IL12RB2, we do report that BD in Iran is strongly associated with HLA-B*51, MICA-A6, and the three HLA-linked SNPs (odds ratio (OR) = 3.38, P = 6.21 × 10(-14); OR = 2.08, P = 1.58 × 10(-13); and OR = 1.67-4.05, P = 1.45 × 10(-04) to 4.79 × 10(-34), respectively). Our data further indicate that the robust HLA-B/MICA association may be explained by a single variant (rs76546355) between the two genes. Overall, these data contribute to a better appraisal of the intriguing linkage between BD and the ancient Silk Route, spanning from the Mediterranean shores to Japan.

A de novo ADCY5 mutation causes early-onset autosomal dominant chorea and dystonia

IMPORTANCE

Apart from Huntington's disease, little is known of the genetics of autosomal dominant chorea associated with dystonia. Here we identify adenylate cyclase 5 (ADCY5) as a likely new causal gene for early-onset chorea and dystonia.

OBSERVATIONS

Whole exome sequencing in a three-generation family affected with autosomal dominant chorea associated with dystonia identified a single de novo mutation—c.2088+1G>A in a 5' donor splice-site of ADCY5—segregating with the disease. This mutation seeming leads to RNA instability and therefore ADCY5 haploinsufficiency.

CONCLUSIONS AND RELEVANCE

Our finding confirms the genetic/clinical heterogeneity of the disorder; corroborated by previous identification of ADCY5 mutations in one family with dyskinesia-facial myokymia and in two unrelated sporadic cases of paxoysmal choreic/dystonia-facial myokymia; ADCY5's high expression in the striatum and movement disorders in ADCY5-deficient mice. Hence ADCY5 genetic analyses may be relevant in the diagnostic workup of unexplained early-onset hyperkinetic movement disorders.

Chronic Mesobuthus gibbosus scorpionism related to the sting in vein

BACKGROUND

A small amount of data is already presented in the relevant literature related to the medical facts of scorpionism caused by Yellow scorpion (Mesobuthus gibbosus: M. gibbosus). Undoubtedly, it is considered as dangerous to human health. This paper presents an unusual case of scorpionism after the sting in vein.

CASE REPORT

A 25 year old male was bitten by M. gibbosus. He experienced extremely severe intermittent pain in the right feet, followed by pulsating and glowing sensations, cold sweat and paleness. 15 minutes after the sting, the pain started to spread through the medial side of the leg, up to the inguinal region. Patient became excited, and experienced occasional spasms of leg muscles. A month after, the bitten vein of dorsal arch of the foot and v. sephena magna became non-uniformly tortuously spread through the entire length. On physical examination four years after the sting, the enlargement of the veins still exists, periodical tingling, and occasional muscle twitches during the night.

CONCLUSIONS

M. gibbosus is endemic in Mediterranean area and represents a real hazard for local inhabitants and tourists. The medical treatment of this type of scorpionism is exclusively symptomatic.

Arthropods and their products as aphrodisiacs--review of literature

After a short review of impotence, the definitions of erectants and aphrodisiacs are presented. The Authors propose division of arthropods according to the places of effect. The description of particular arthropods with their pictures and nomenclature, is followed by certain or probable mechanisms of achieving the aphrodisiac and sometimes toxic effect, that were available in the literature since 1929 till nowadays. We mention the most usual locations, mainly in Asia, where they are found and consumed, but also, we describe the manner of preparing and intake. The review includes the following arthropods: lobster, Arizona bark scorpion, deathstalker, banana spider, Mediterranean black widow, Burmeister's triatoma, giant water bug, diving-beetle, Korean bug, diaclina, flannel moth, Spanish fly, migratory locust, red wood ant and honeybee.

The non-conventional MHC class I MR1 molecule controls infection by Klebsiella pneumoniae in mice

As opposed to the well established role of MHC-linked, polymorphic, class I (MHC-I) genes in adaptive immunity, a universal role for non-conventional MHC-I is unknown, thus requiring a case-by-case study. The MHC unlinked, monomorphic, but β₂microglobulin (β₂m)-associated "MHC class I related" MR1 molecule interacts with a semi-invariant TCR. The pathophysiology of this interaction or more importantly of this peculiar MHC-I remains mostly unknown. Recently it was shown that β₂m deficient mice were more susceptible to infection by Klebsiella pneumoniae, a widely spread Gram-negative bacteria that causes diverse and often severe ailments in man. Here we demonstrate, using both an in vivo imaging system and survival tests, the increased susceptibility to K. pneumoniae (but not to several other Gram negative bacteria) of MR1 deficient mice. This is accompanied by a consequent change in body temperature and systemic cytokine profile. Hence MR1 controls K. pneumoniae infection in vivo.

Lipolysis is altered in MHC class I zinc-α2-glycoprotein deficient mice

Non-conventional major histocompatibility complex class I molecules are involved in a variety of physiological functions, most at the periphery of the immune system per se. Zinc-alpha(2)-glycoprotein (ZAG), the sole soluble member of this superfamily has been implicated in cachexia, a poorly understood yet life-threatening, severe wasting syndrome. To further ascertain the role of ZAG in lipid metabolism and perhaps the immune system, we inactivated both ZAG alleles by gene targeting in mice. Subjecting these ZAG deficient animals to standard or lipid rich food regimens led to increased body weight in comparison to identically treated wild-type mice. This phenotype appeared to correlate with a significant decrease in adipocytic lipolysis that could not be rescued by several pharmacological agents including beta(3)-adrenoreceptor agonists. Furthermore, in contrast to previously reported data, ZAG was found to be ubiquitously and constitutively expressed, with an especially high level in the mouse liver. No overt immunological phenotype was identified in these animals.

MIC and other NKG2D ligands: from none to too many

NKG2D, a prime activatory receptor on human NK, CD8(+) alphabeta and gammadelta cells, has a variety of ligands, which, despite sharing membership of the MHC class I structural club, display an array of unique features. Chronologically, human MIC molecules were the first NKG2D ligands to be identified. Then came RAET1 (ULBP) molecules, which were identified in both man and mouse, as well as H60 and MULT1, which have no counterparts in man to date. The question remains as to why, more than how, the evolutionary conserved, apparently monomorphic, single copy, NKG2D, can/should adapt to this variety of ligands, and when it does, what is the evolutionary advantage of this profusion of ligands for a single receptor?

In vivo immunogenetics: from MIC to RAET1 loci

The major histocompatibility complex (MHC) comprises approximately one thousandth of the genome and encompasses its most polymorphic members. This diversity enables the MHC, at the population level, to counteract the extraordinarily diverse microbiological threats. Reviewed here are two separate sets of MHC class I genes: MIC and RAET1. Whilst the former are encoded within the MHC (6p21.3), the latter are located on the opposite arm of the same chromosome (6q24.2-q25.3). Differing from the prototypical class I genes in structure, transcription, diversity and potential function, they both exemplify the versatility of the MHC fold, despite convergence onto a single ligand, the activatory C-type lectin-like receptor, NKG2D. Why the immune system uses two distinct gene families to interact with a unique ligand remains a fascinating question. To answer this question, the reader will be chronologically exposed to the field whilst following a single thread, i.e. genomics and gene diversity.

Selection of evolutionarily conserved mucosal-associated invariant T cells by MR1

The evolutionary conservation of T lymphocyte subsets bearing T-cell receptors (TCRs) using invariant alpha-chains is indicative of unique functions. CD1d-restricted natural killer T (NK-T) cells that express an invariant Valpha14 TCRalpha chain have been implicated in microbial and tumour responses, as well as in auto-immunity. Here we show that T cells that express the canonical hValpha7.2-Jalpha33 or mValpha19-Jalpha33 TCR rearrangement are preferentially located in the gut lamina propria of humans and mice, respectively, and are therefore genuine mucosal-associated invariant T (MAIT) cells. Selection and/or expansion of this population requires B lymphocytes, as MAIT cells are absent in B-cell-deficient patients and mice. In addition, we show that MAIT cells are selected and/or restricted by MR1, a monomorphic major histocompatibility complex class I-related molecule that is markedly conserved in diverse mammalian species. MAIT cells are not present in germ-free mice, indicating that commensal flora is required for their expansion in the gut lamina propria. This indicates that MAIT cells are probably involved in the host response at the site of pathogen entry, and may regulate intestinal B-cell activity.

Iron overload in mice expressing HFE exclusively in the intestinal villi provides evidence that HFE regulates a functional cross-talk between crypt and villi enterocytes

Hereditary hemochromatosis (HH), a common autosomal recessive disorder due to a mutation in HFE, which encodes an atypical MHC class I glycoprotein, is characterized by excessive absorption of dietary iron. Little is known however of the apparently complex pathophysiology of HFE involvement in the process of iron influx. Here, in order to tackle the issue in vivo, we decided to target HFE expression exclusively to the relevant tissue, intestinal epithelium. This was achieved by putting HFE under transcriptional control of the rat fatty acid binding protein (Fabpi) promoter. Quite unexpectedly, Fabpi-HFE mice had significantly elevated serum transferrin saturation levels in comparison to those of normal littermates. By a careful, layer by layer analysis of transgene expression along the crypt-villus axis, we were able to affirm that the ectopic expression of transgenic HFE in the differentiated villi enterocytes was responsible for ferric hyperabsorption, a phenomenon exacerbated in the absence of endogenous HFE expression, which we assessed by crossing the transgene onto an HFE(-/-) (knockout) background. This forced dichotomy between the absence of HFE in the crypt and expression in the villi provides experimental support that HFE functions as a "gatekeeper," regulating the cross-talk between the crypt and villi enterocytes and thereby modulating the avidity of mature enterocytes for dietary iron.

A basolateral sorting motif in the MICA cytoplasmic tail

The MHC class I chain-related MICA molecule is a stress-induced, highly polymorphic, epithelia-specific, membrane-bound glycoprotein interacting with the activating NK cell receptor NKG2D and/or gut-enriched Vdelta1-bearing gammadelta T cells. We have previously reported the presence of a MICA transmembrane-encoded short-tandem repeat harboring a peculiar allele, A5.1, characterized by a frame shift mutation leading to a premature intradomain stop codon, thus denying the molecule of its 42-aa cytoplasmic tail. Given that this is the most common population-wide MICA allele found, we set out to analyze the functional consequences of cytoplasmic tail deletion. Here, we show native expression of MICA at the basolateral surface of human intestinal epithelium, the site of putative interaction with intraepithelial T and NK lymphocytes. We then demonstrate, in polarized epithelial cells, that although the full-length MICA protein is sorted to the basolateral membrane, the cytoplasmic tail-deleted construct as well as the naturally occurring A5.1 allele are aberrantly transported to the apical surface. Site-directed mutagenesis identified the cytoplasmic tail-encoded leucine-valine dihydrophobic tandem as the basolateral sorting signal. Hence, the physiological location of MICA within epithelial cells is governed by its cytoplasmic tail, implying impairment in A5.1 homozygous individuals, perhaps relevant to the immunological surveillance exerted by NK and T lymphocytes on epithelial malignancies.

Inactivation of the hemochromatosis gene differentially regulates duodenal expression of iron-related mRNAs between mouse strains

BACKGROUND & AIMS

Hfe knockout mice, like patients with hereditary hemochromatosis, have augmented duodenal iron absorption and increased iron deposition in hepatic parenchymal cells. The goals of the present study were to gain further insight into the control of iron absorption by comparing the transcript levels of iron-related genes in the duodenum of DBA/2 Hfe-/- mice, susceptible to iron loading, and wild-type controls, and to test whether variations in the duodenal expression of these messengers contribute to the DBA/2 and C57BL/6 strain differences in the severity of hepatic iron loading.

METHODS

Expression of the different transcripts was quantified by real-time polymerase chain reaction.

RESULTS

The 2 strains differ strikingly, not only in the severity of hepatic iron loading, but also in the duodenal expression of iron-related genes. In DBA/2 Hfe-/- mice, increased intestinal iron absorption results from the concomitant up-regulation of the Dcytb, DMT1, and FPN1 messengers. No increase in the expression of these messengers is seen in C57BL/6 Hfe-/- mice.

CONCLUSIONS

The up-regulation of these transcripts suggests that an inappropriate iron-deficiency signal is sensed by the duodenal enterocytes, leading to an enhanced ferric reductase activity and the increase of duodenal iron uptake and transfer to the circulation. The genes modifying the hemochromatosis phenotype probably act by modifying the expression of these 3 messengers.

A cluster of ten novel MHC class I related genes on human chromosome 6q24.2-q25.3

We have identified a novel family of human major histocompatibility complex (MHC) class I genes. This MHC class I related gene family is defined by 10 members, among which 6 encode potentially functional glycoproteins. The 180-kb cluster containing them has been generated by serial duplication and minimal diversification of an ancestral prototype. They are not located within the MHC on 6p21.3, but near the tip of its long arm at q24.2-q25.3, close to the human equivalent of the mouse H2-linked t-complex, a subchromosomal region syntenic to a segment of mouse chromosome 10 harboring the orthologous MHC class I related retinoic acid early transcript loci, Raet1a-d. Hence we have named the identified loci RAET1E-N. Human RAET1 products are all devoid of the membrane-proximal immunoglobulin-like alpha3 domain and most, but not all, are predicted to remain membrane-anchored via glycosylphosphatidylinositol linkage and are shown to display an atypical pattern of polymorphism. RAET1 transcripts are absent from hematopoietic tissues, but largely expressed in tumors. The involvement of orthologous mouse RAET1A-D/H60 in natural killer and T-cell activation through NKG2D engagement augurs a similar function for the human RAET1 proteins.

Candida catenulata fungemia in a cancer patient

We report the first case of fungemia due to Candida catenulata, a contaminant of dairy products. C. catenulata was isolated from three blood cultures of a patient with gastric cancer. The patient failed to respond to fluconazole but recovered after treatment was switched to amphotericin B. In vitro, C. catenulata was susceptible to amphotericin B and itraconazole and was also susceptible to fluconazole in dose-dependent manner. The likely portal of entry was the digestive tract, as the patient often ate cheese and had multiple gastric ulcerations.

AIDS Primary Central Nervous System Lymphoma: Molecular Analysis of the Expressed VH Genes and Possible Implications for Lymphomagenesis

AIDS-associated primary central nervous system lymphomas are late events that have an extremely poor prognosis. Despite different hypotheses, the brain localization of these B cell lymphomas remains an enigma. To better define the cell origin of the lymphomas and the possible role of the B cell receptor (BCR) in the brain localization and/or in the oncogenic transformation, we analyzed the V region genes of the Ig heavy chain expressed by lymphoma cells in five randomly selected patients. After amplifying the rearranged VHDJH DNA by PCR, cloning, and sequencing of the amplified products, we observed that: 1) of the five lymphomas analyzed, four were clearly monoclonal; 2) there was no preferential use of one peculiar VH family or one peculiar segment of gene; 3) the mutation analysis showed that an Ag-driven process occurred in at least two cases, probably before the oncogenic event; and 4) there was no intraclonal variability, suggesting that the hypermutation mechanism is no longer efficient in these lymphoma B cells. Taken together, our results suggest that distinct Ags could be recognized by the BCR of the lymphoma cells in different patients and that, if the Ags are responsible for the brain localization of these B cells bearing mutated BCR, other factors must be involved in B cell transformations in primary central nervous system lymphoma.

AIDS primary central nervous system lymphoma: molecular analysis of the expressed VH genes and possible implications for lymphomagenesis

AIDS-associated primary central nervous system lymphomas are late events that have an extremely poor prognosis. Despite different hypotheses, the brain localization of these B cell lymphomas remains an enigma. To better define the cell origin of the lymphomas and the possible role of the B cell receptor (BCR) in the brain localization and/or in the oncogenic transformation, we analyzed the V region genes of the Ig heavy chain expressed by lymphoma cells in five randomly selected patients. After amplifying the rearranged VHDJH DNA by PCR, cloning, and sequencing of the amplified products, we observed that: 1) of the five lymphomas analyzed, four were clearly monoclonal; 2) there was no preferential use of one peculiar VH family or one peculiar segment of gene; 3) the mutation analysis showed that an Ag-driven process occurred in at least two cases, probably before the oncogenic event; and 4) there was no intraclonal variability, suggesting that the hypermutation mechanism is no longer efficient in these lymphoma B cells. Taken together, our results suggest that distinct Ags could be recognized by the BCR of the lymphoma cells in different patients and that, if the Ags are responsible for the brain localization of these B cells bearing mutated BCR, other factors must be involved in B cell transformations in primary central nervous system lymphoma.

123I-vasoactive intestinal peptide (VIP) receptor scanning: update of imaging results in patients with adenocarcinomas and endocrine tumors of the gastrointestinal tract

Recent data suggest that functional receptors (R) for vasoactive intestinal peptide (VIP) are expressed on various tumor cells. The high-level expression of VIPR on tumor cells provided the basis for the successful use of 123I-labeled VIP for the in vivo localization of intestinal adenocarcinomas and endocrine tumors. We here report an update of our imaging results using 123I-VIP (150-200 MBg/1 microgram/patient) in 169 patients. In patients with pancreatic adenocarcinomas without liver metastases, the primary/recurrent tumor was visualized in 16 of 18 patients (89%) and liver metastases were imaged in 15 of 16 patients. In 11 of 12 patients with colorectal adenocarcinomas, the primary/recurrent tumor (92%) was imaged by 123I-VIP. Also, in 21 of 25 patients, liver metastases (84%); in 3 of 6 patients, lung metastases (50%); and in 4 of 5 patients, lymph-node metastases (80%) were imaged by 123I-VIP. In 10 of 10 patients with gastric adenocarcinomas, the primary/recurrent tumor; in 3 of 4 patients, liver metastases; and in 2 of 2 patients, lymph-node metastases were visualized by 123I-VIP. 123I-VIP localized primary intestinal carcinoid tumors in 15 of 17 patients (88%) and 8 of 10 primary insulinomas (80%). We conclude that the 123I-VIPR scintigraphy localizes intestinal adenocarcinomas and endocrine tumors as well as metastatic tumor sites.

Development of an avian model for restenosis

Recurrence of atherosclerotic plaque growth after interventional therapy, restenosis, is a significant clinical problem occurring in 20%-50% of cases. We have developed a new avian model for the investigation of restenosis after arterial injury in cholesterol fed White Leghorn roosters. Atherosclerotic plaque growth 1-30 weeks after angioplasty balloon mediated endothelial injury in the abdominal aorta was studied in 37 roosters. Roosters were maintained on either normal poultry diet or high cholesterol diet. Twelve cholesterol fed roosters were also fed a hormone supplemented diet in order to modify plaque morphology. The procedural success rate was high. Angiographic stenoses (mean 36% with maximum of 74%) were detectable in cholesterol fed roosters after balloon angioplasty with associated histological evidence of plaque growth (P < 0.017). Cholesterol feeding enhanced fatty plaque growth; hormone manipulation increased calcific and ulcerated plaque but with high associated morbidity. Three interventional devices were subsequently examined in 32 roosters (16 laser angioplasty, 7 atherectomy, and 9 stent implant). Plaque development was again assessed by contrast angiography and histological analysis. We conclude that balloon mediated arterial injury in cholesterol fed roosters produces early proliferative and late, complex atherosclerotic lesions providing an inexpensive model for plaque development after intimal injury.

Elevated levels of serum carbohydrate deficient transferrin are not specific for alcohol abuse in patients with liver disease

BACKGROUND

Serum carbohydrate deficient transferrin is a marker of chronic alcohol consumption; it increases above normal in healthy individuals after a daily alcohol intake of more than 60 g/d for more than 2 weeks. The influence of liver disease itself on carbohydrate deficient transferrin levels has not been sufficiently established.

METHODS

We investigated serum levels of carbohydrate deficient transferrin in 196 consecutive patients admitted to our Gastroenterology and Hepatology Unit and correlated this parameter with the patients' statements about alcohol intake during the previous 2 weeks and with other markers of chronic alcohol consumption.

RESULTS

In our patient population, carbohydrate deficient transferrin had the best overall performance with respect to sensitivity (88%), specificity (82%), and negative predictive value (98%), as compared to other markers, although specificity was much lower than previously reported in patients without liver disease. In the group of patients with liver disease, sensitivity and specificity were 90% and 73%, respectively, and in patients without liver disease, 80% and 88%. The negative predictive value was excellent (96% for patients with liver disease and 99% for patients without liver disease).

CONCLUSIONS

Thus, in a patient with a negative interview for chronic alcohol abuse and normal carbohydrate deficient transferrin level, alcohol is unlikely to be the cause of liver disease, and further investigations to establish the etiology of liver disease are warranted. An increased carbohydrate deficient transferrin level, however, cannot be regarded as reliable evidence for chronic alcohol abuse in patients with liver disease.

Role of thyroid hormone in the expression of apolipoprotein A-IV and C-III genes in rat liver

The genes coding for apolipoproteins A-I, C-III, and A-IV are closely linked to one another in the rat genome. Thyroid hormone stimulates apoA-I expression in rat liver by an unusual mechanism that enhances the maturation of mRNA. This hormone also increases apoA-IV mRNA abundance by a mechanism not yet studied, and its role in the expression of apoC-III has not been defined but may be of relevance to the metabolism of triglyceride-rich lipoproteins. We therefore measured the transcriptional activity of the apoA-IV and apoC-III genes and the abundance of their nuclear RNA and total cellular mRNA in livers of control rats and rats made hyper- and hypothyroid. After a single receptor-saturating dose of triiodothyronine (3 mg/100 g body weight), apoA-IV gene transcription increased at 20 min and reached a maximum of 260% of control at 6 h. Increases of transcription were reflected in increases of nuclear and total apoA-IV mRNA levels. ApoC-III gene transcription was temporarily increased to 160% at 2 h without changes in the abundance of its nuclear or total mRNA over 24 h. Lower hormone doses (20-500 micrograms/100 g body weight) stimulated apoA-IV mRNA transcription as well, but tended to reduce transcription from the apoC-III gene. Upon chronic administration of thyroid hormone, apoA-IV transcription decreased to 55% and nuclear apoA-IV RNA levels to 87% of control. However, total cellular apoA-IV mRNA levels increased to 279% of control, implying stabilization of mRNA in the cytoplasm. ApoC-III transcription decreased to 28% of control, but abundance of nuclear and total cellular apoC-III mRNA was reduced to a lesser extent. In hypothyroid rats, apoA-IV gene expression was decreased fourfold at the transcriptional level. In contrast, apoC-III gene transcription increased to 178% of control, but the abundance of nuclear and total cellular apoC-III mRNA did not differ from control rats. Thus, thyroid hormone affects the abundance of apoA-IV mRNA by changing its synthesis and its rate of degradation and enhances the efficiency of apoC-III mRNA maturation, thereby blunting the net effect of altered mRNA synthesis on mRNA abundance.

Effect of sucrose diet on expression of apolipoprotein genes A-I, C-III and A-IV in rat liver

A sucrose-rich diet stimulates hepatic lipogenesis and induces net production of very low density lipoproteins in the liver. To study changes of hepatic apolipoprotein gene expression in response to such a diet, we measured the mRNA abundance of apolipoproteins A-I, C-III and A-IV in livers of rats fed a sucrose-rich diet or a control diet for 3 weeks. In livers of sucrose-fed rats, the abundance of cellular and nuclear apo A-IV mRNA increased to 185% +/- 21% and 142% +/- 22% of control values (P less than 0.01), respectively. In sucrose-fed rats, the transcriptional activity of the apo A-IV gene, measured in a cell-free transcription system using isolated liver nuclei, increased to 144% +/- 23% of control (P less than 0.05). In contrast, this diet neither affected the abundance of cellular and nuclear apo A-I and apo C-III mRNA nor the transcriptional activity of these genes in liver. These results are consistent with specialization of the regulatory elements of the genes coding for apolipoproteins A-I, C-III and A-IV. Alternatively, enhanced transcription of the apo A-IV gene may preclude increased synthesis of apo A-I and/or apo C-III mRNA due to the close linkage of the three genes in the rat genome.

Specific postendocytic proteolysis of apolipoprotein B in oocytes does not abolish receptor recognition

Upon receptor-mediated transfer of plasma very low density lipoprotein (VLDL) particles into growing chicken oocytes, their major apolipoprotein (apo) component, apoB, is proteolytically cleaved. apoB fragmentation appears to be catalyzed by cathepsin D or a similar pepstatin A-sensitive protease and results in the presence of a characteristic set of polypeptides on yolk VLDL particles. The nicks introduced into the apoB backbone during postendocytic processing occur in yolk platelets and appear to prepare internalized VLDL for storage in yolk. Since yolk VLDL binds to chicken receptors specific for apoB-containing lipoproteins in identical fashion to plasma VLDL, the possibility exists that the developing embryo utilizes yolk VLDL as a nutrient by way of receptor-mediated endocytosis.