Deliberate foreign body ingestion in patients with underlying mental illness: A retrospective multicentre study

OBJECTIVE

Deliberate foreign body ingestion (DFBI) is characterised by recurrent presentations among patients with mental health conditions, intellectual disabilities and in prisoners. We aimed to profile the characteristics and evaluate the care of such patients in this study.

METHODS

Adult patients with an endoscopic record of attempted foreign body retrieval between January 2013 and September 2020 were identified at three Australian hospitals. Those with a documented mental health diagnosis were included and their standard medical records reviewed. Presentation history, demographics, comorbidities and endoscopic findings were recorded and described.

RESULTS

A total of 166 admissions were accounted for by 35 patients, 2/3 of which had borderline personality disorder (BPD). Repetitive presentations occurred in more than half of the cohort. There was an increased trend of hospital admissions throughout the years. At least half of the cohort had a documented mental health review during their admission. An average of 3.3 (2.9) foreign bodies were ingested per single episode. Endoscopic intervention was performed in 76.5% of incidents. The combined Length of stay for all patients was 680 days.

CONCLUSION

Deliberate foreign body ingestion in mental health patients is a common, recurring and challenging problem that is increasing in frequency and requires collaborative research to further guide holistic management.

Tumor associated antigen PRAME exhibits dualistic functions that are targetable in diffuse large B-cell lymphoma

PRAME is a prominent member of the cancer testis antigen family of proteins, which triggers autologous T cell–mediated immune responses. Integrative genomic analysis in diffuse large B cell lymphoma (DLBCL) uncovered recurrent and highly focal deletions of 22q11.22, including the PRAME gene, which were associated with poor outcome. PRAME-deleted tumors showed cytotoxic T cell immune escape and were associated with cold tumor microenvironments. In addition, PRAME downmodulation was strongly associated with somatic EZH2 Y641 mutations in DLBCL. In turn, PRC2-regulated genes were repressed in isogenic PRAME-KO lymphoma cell lines, and PRAME was found to directly interact with EZH2 as a negative regulator. EZH2 inhibition with EPZ-6438 abrogated these extrinsic and intrinsic effects, leading to PRAME expression and microenvironment restoration in vivo. Our data highlight multiple functions of PRAME during lymphomagenesis and provide a preclinical rationale for synergistic therapies combining epigenetic reprogramming with PRAME-targeted therapies.

Real-world outcomes of unrestricted direct-acting antiviral treatment for hepatitis C in Australia: The South Australian statewide experience

In March 2016, the Australian government offered unrestricted access to direct-acting antiviral (DAA) therapy for chronic hepatitis C virus (HCV) to the entire population. This included prescription by any medical practitioner in consultation with specialists until sufficient experience was attained. We sought to determine the outcomes and experience over the first twelve months for the entire state of South Australia. We performed a prospective, observational study following outcomes of all treatments associated with the state's four main tertiary centres. A total of 1909 subjects initiating DAA therapy were included, representing an estimated 90% of all treatments in the state. Overall, SVR12 was 80.4% in all subjects intended for treatment and 95.7% in those completing treatment and follow-up. 14.2% were lost to follow-up (LTFU) and did not complete SVR12 testing. LTFU was independently associated with community treatment via remote consultation (OR 1.50, 95% CI 1.04-2.18, P = .03), prison-based treatment (OR 2.02, 95% CI 1.08-3.79, P = .03) and younger age (OR 0.98, 95% CI 0.97-0.99, P = .05). Of the 1534 subjects completing treatment and follow-up, decreased likelihood of SVR12 was associated with genotype 2 (OR 0.23, 95% CI 0.07-0.74, P = .01) and genotype 3 (OR 0.23, 95% CI 0.12-0.43, P ≤ .01). A significant decrease in treatment initiation was observed over the twelve-month period in conjunction with a shift from hospital to community-based treatment. Our findings support the high responses observed in clinical trials; however, a significant gap exists in SVR12 in our real-world cohort due to LTFU. A declining treatment initiation rate and shift to community-based treatment highlight the need to explore additional strategies to identify, treat and follow-up remaining patients in order to achieve elimination targets.

PIN1 expression contributes to hepatic carcinogenesis

The phospho-Ser/Thr-Pro specific prolyl-isomerase PIN1 is over-expressed in more than 50% of hepatocellular carcinomas (HCCs). To investigate its potential oncogenicity, we over-expressed PIN1 in a non-transformed human liver cell line MIHA. This resulted in up-regulation of beta-catenin and cyclin D1, leading to anchorage-independent growth in soft agar and tumorigenicity in nude mice. To further validate the role of PIN1 in hepatocarcinogenesis, PIN was suppressed by RNA interference (siRNA) in the HCC cell line PLC/PRF/5. siRNA-PIN1 transfection of PLC/PRF/5 cells led to repression of PIN1 expression, resulting in decreased levels of beta-catenin and cyclin D1. siRNA-PIN1 transfectants showed lower cell proliferation rates, reduced colony formation, and retarded cell cycle progression, with an increase in cells residing in G0/G1. Furthermore, soft agar colony formation was depressed, and tumorigenicity in nude mice was abrogated. These findings implicate PIN1 expression as an important step in hepatic carcinogenesis.

Clinicopathologic features and treatment outcome of mature T-cell and natural killer-cell lymphomas diagnosed according to the World Health Organization classification scheme: a single center experience of 10 years

BACKGROUND

Data on mature T-cell and natural killer (NK)-cell lymphomas diagnosed with the World Health Organization (WHO) classification scheme are scarce. They are regarded to be more common in Asian populations.

METHODS

Consecutive T-cell and NK-cell lymphomas classified according to the WHO scheme within 10 years in a Chinese population were reviewed.

RESULTS

There were 148 cases, constituting 16.6% (T-cell, n=90, 10.1%, NK-cell, n=58, 6.5%) of all non-Hodgkin lymphomas in this period. There was a male predominance (male:female = 2.5), young age at diagnosis (median age 50 years, range 8-86) and frequent extranodal presentation. Commonest T-cell lymphomas included anaplastic large cell lymphoma (ALCL, n=25, median age 35 years, nodal 60%, stage I/II 60%), peripheral T-cell lymphoma, unspecified (PTCL, n=24, median age 54 years, nodal 42%, stage I/II 42%), and angioimmunoblastic T-cell lymphoma (AILT, n=19, median age 67 years, nodal 95%, stage I/II 26%). Overall frequencies of T-cell lymphomas were comparable to Western patients. AILT, PTCL and ALCL were aggressive with a poor outcome. NK-cell lymphomas were predominantly extranodal (96%) and aggressive, with a frequency much higher than Western patients.

CONCLUSIONS

The apparent high prevalence of T-cell and NK-cell lymphomas in the Chinese was due to more frequent NK-cell but not T-cell lymphomas.

Null mutation of the Lmo4 gene or a combined null mutation of the Lmo1/Lmo3 genes causes perinatal lethality, and Lmo4 controls neural tube development in mice

The LIM-only family of proteins comprises four members; two of these (LMO1 and LMO2) are involved in human T-cell leukemia via chromosomal translocations, and LMO2 is a master regulator of hematopoiesis. We have carried out gene targeting of the other members of the LIM-only family, viz., genes Lmo1, Lmo3 and Lmo4, to investigate their role in mouse development. None of these genes has an obligatory role in lymphopoiesis. In addition, while null mutations of Lmo1 or Lmo3 have no discernible phenotype, null mutation of Lmo4 alone causes perinatal lethality due to a severe neural tube defect which occurs in the form of anencephaly or exencephaly. Since the Lmo1 and Lmo3 gene sequences are highly related and have partly overlapping expression domains, we assessed the effect of compound Lmo1/Lmo3 null mutations. Although no anatomical defects were apparent in compound null pups, these animals also die within 24 h of birth, suggesting that a compensation between the related Lmo1 and 3 proteins can occur during embryogenesis to negate the individual loss of these genes. Our results complete the gene targeting of the LIM-only family in mice and suggest that all four members of this family are important in regulators of distinct developmental pathways.

Evaluation of the role of lipoprotein metabolism genes in systemic cationic liposome-mediated gene transfer in vivo

Germ line gene disruption and gene insertion are often used to study the function of selected genes in vivo. We used selected knockout and transgenic mouse models to attempt to identify lipoprotein-related genes and gene products that regulate the process of intravenous cationic liposome-DNA complex (CLDC)-based gene delivery. Several observations suggested that proteins involved in lipoprotein metabolism might be important in influencing the delivery and/or expression of CLDC. First, in vitro transfection of either K562 or CHO cells by CLDCs was enhanced by the presence of a functional low-density lipoprotein receptor (LDLR). Second, pretreatment of mice with 4-aminopyrazolopyrimidine (4APP), an agent that alters lipoprotein profiles in mice, significantly decreased expression of luciferase (luc) after intravenous injection of CLDC-luc complexes in mice. Therefore, we tested mouse model systems either deficient for, or overexpressing, selected genes involved in lipoprotein metabolism, for their potential to regulate intravenous, CLDC-based gene delivery. Although homozygous knockout mutation in the apoE gene caused a significant decrease in gene expression in many tissues of apoE-deficient mice, mice with homozygous deletion of both the apoE and LDLR genes showed wild-type levels of gene transfer efficiency. Thus, a secondary event, produced by homozygous deletion of apoE, but compensated for by the concomitant deletion of LDLR, and/or effects resulting from strain-related, genetic background differences, appeared to play a significant role in mediating intravenous, CLDC-based gene delivery. Secondary alterations resulting from germ line knockouts, as well as epigenetic effects produced by strain differences, may limit the ability to assign specific, gene transfer-related functions to the deleted gene.

Two distal downstream enhancers direct expression of the human apolipoprotein E gene to astrocytes in the brain

Two distal downstream enhancers controlling astrocyte expression of the human apolipoprotein E (apoE) gene in the brain were identified by analysis of transgenic mice generated with various constructs of the apoE/C-I/C-IV/C-II gene cluster. In wild-type mice, the highest overall levels of apoE mRNA were found in astrocytes in the glomerular layer of olfactory bulbs and in Bergmann glia in the cerebellum. This pattern of expression was reproduced in transgenic mice expressing the entire human apoE gene cluster and also in transgenic mice expressing specific enhancer segments within the cluster. Expression of the human apoE transgene at these sites was specified by two enhancer domains: one enhancer is located 3.3 kb downstream of the apoE gene, and a duplication of this sequence is located 15 kb downstream of the apoE gene. Astrocyte enhancer activity was contained within 620 and 619 bp segments of these domains that show subtle differences in regional expression. In the absence of these distal enhancers, the apoE gene was not expressed in astrocytes. The relatively high levels of apoE expression at specific sites in the olfactory bulb and cerebellum suggest the presence of unique regulatory signals at these locations that may reflect common cellular properties and apoE gene functions. The localization of the two astrocytic enhancers reveals an unexpected complexity in the control of apoE production that is essential to understanding apoE function in the brain.

Expression of the apolipoprotein E gene in the skin is controlled by a unique downstream enhancer

A distal enhancer that specifies apolipoprotein E gene expression in the skin was identified and characterized by in situ hybridization in transgenic mice generated with constructs of the human apolipoprotein E/C-I/C-IV/C-II gene cluster. Transgene constructs containing the enhancer expressed high levels of apolipoprotein E mRNA in the germinative cell layer of the sebaceous gland and in epithelial cells of the hair follicle root sheath. Apolipoprotein E mRNA was also detected in basal epithelial cells of the epidermis. Expression of the human apolipoprotein E transgene at these sites was specified by a unique 1.0 kb enhancer domain located 1.7 kb downstream of the apolipoprotein E gene. No transgene expression was detected in skin epithelial cells in transgenic mice when this enhancer was deleted from the apolipoprotein E gene cluster. The enhancer was used to construct a transgene expression vector that faithfully directed a heterologous cDNA to the normal sites of apolipoprotein E gene expression in epithelial cells of the skin.

Mouse Models of Human Chromosomal Translocations and Approaches to Cancer Therapy

Cancer arises because of genetic changes in somatic cells, eventually giving rise to overt malignancy. Principle among genetic changes found in tumor cells are chromosomal translocations which give rise to fusion genes or enforced oncogene expression. These mutations are tumor-specific and result in production of tumor-specific mRNAs and proteins and are attractive targets for therapy. Also, in acute leukemias, many of these molecules are transcription regulators which involve cell-type-specific complexes, offering an alternative therapy via interfering with protein-protein interaction. We are studying these various features of tumor cells to evaluate new therapeutic methods. We describe a mouse model of de novo chromosomal translocations using the Cre-loxP system in which interchromosomal recombination occurs between the Mll and Af9 genes. We are also developing other in vivo methods designed, like the Cre-loxP system, to emulate the effects of these chromosomal abnormalities in human tumors. In addition, we describe new technologies to facilitate the intracellular targeting of fusion mRNAs and proteins resulting from such chromosomal translocations. These include a masked antisense RNA method with the ability to discriminate between closely related RNA targets and the selection and use of intracellular antibodies to bind to target proteins in vivo and cause cell death. These approaches should also be adaptable to targeting point mutations or to differentially expressed tumor-associated proteins. We hope to develop therapeutic approaches for use in cancer therapy after testing their efficacy in our mouse models of human cancer.

Intracellular antibody-caspase-mediated cell killing: an approach for application in cancer therapy

Antibodies have been expressed inside cells in an attempt to ablate the function of oncogene products. To make intracellular antibodies more generally applicable and effective in cancer therapy, we have devised a method in which programmed cell death or apoptosis can be triggered by specific antibody-antigen interaction. When intracellular antibodies are linked to caspase 3, the "executioner" in the apoptosis pathway, and bind to the target antigen, the caspase 3 moieties are self-activated and thereby induce cell killing. We have used this strategy in a model system with two pairs of intracellular antibodies and antigens. In vivo coexpression of an antibody-caspase 3 fusion with its antigenic target induced apoptosis that was specific for antibody, antigen, and active caspase 3. Moreover, the antibody-caspase 3 fusion protein was not toxic to cells in the absence of antigen. Therefore, intracellular antibody-mediated apoptosis should be useful as a specific therapeutic approach for the treatment of cancers, a situation where target cell killing is required.

Duplicated downstream enhancers control expression of the human apolipoprotein E gene in macrophages and adipose tissue

Two distal enhancers that specify apolipoprotein (apo) E gene expression in isolated macrophages and adipose tissue were identified in transgenic mice that were generated with constructs of the human apoE/C-I/C-I'/C-IV/C-II gene cluster. One of these enhancers, multienhancer 1, consists of a 620-nucleotide sequence located 3.3 kilobases (kb) downstream of the apoE gene. The second enhancer, multienhancer 2, is a 619-nucleotide sequence located 15.9 kb downstream of the apoE gene and 5.9 kb downstream of the apoC-I gene. The two enhancers are 95% identical in sequence, and they are likely to have arisen as a consequence of the gene duplication event that yielded the apoC-I gene and the apoC-I' pseudogene. Both enhancer sequences appear to have equivalent activity in directing apoE gene expression in peritoneal macrophages and in adipocytes, suggesting that their activity in specific cell types may be determined by common regulatory elements.

Characterization of the Lmo4 gene encoding a LIM-only protein: genomic organization and comparative chromosomal mapping

LIM-only (LMO) proteins are transcription regulators that function by mediating protein-protein interaction and include the T cell oncogenes encoding LMO1 and LMO2. The oncogenic functions of LMO1 and LMO2 are thought to be mediated by interaction with LDB1 since they form a multimeric protein complex(es). A new member of the Lmo family, Lmo4, has also recently been identified via its interaction with Ldb1. Sequence analysis of the mouse Lmo4 gene shows that it spans about 18 kb and consists of at least six exons, including two alternatively spliced 5' exons. Unlike Lmo1, the two 5' exons of Lmo4 do not encode protein. Comparison of the Lmo4 gene structure with the other LMO family members shows the exon structure of Lmo4 differs in the position of exon junctions encoding the second LIM domain and in a novel exon-intron junction at the penultimate codon of the gene. Lmo4 is thus the least conserved known member of the LIM-only family in both nucleotide sequence and exon structure. Physical mapping of the Lmo4/LMO4 genes has shown mouse Lmo4 is located on Chromosome (Chr) 3 and human LMO4 on Chr 1p22.3. This chromosome location is of interest as it occurs in a region that is deleted in a number of human cancers, indicating a possible role of LMO4 in tumorigenesis, like its relatives LMO1 and LMO2.

Selection of antibodies for intracellular function using a two-hybrid in vivo system

Expression of antibodies inside cells has been used successfully to ablate protein function. This finding suggests that the technology should have an impact on disease treatment and in functional genomics where proteins of unknown function are predicted from genomic sequences. A major hindrance is the paucity of antibodies that function in eukaryotic cells, presumably because the antibodies fold incorrectly in the cytoplasm. To overcome this problem, we have developed an in vivo assay for functional intracellular antibodies using a two-hybrid approach. In this assay, antibody, as single-chain Fv (scFv) linked to a transcriptional transactivation domain, can interact with a target antigen, linked to a LexA-DNA binding domain, and thereby activate a reporter gene. We find that several characterized antibodies can bind their target antigen in eukaryotic cells in this two-hybrid format, and we have been able to isolate intracellular binders from among sets of scFv that can bind antigen in vitro. Furthermore, we show a model selection in which a single scFv was isolated from a mixture of half a million clones, indicating that this is a robust procedure that should facilitate capture of antibody specificities from complex mixtures. The approach can provide the basis for de novo selection of intracellular scFv from libraries, such as those made from spleen RNA after immunization with antigen, for intracellular analysis of protein function based only on genomic or cDNA sequences.

Synthesis and cytotoxic action of 3,5-isoxazolidinediones and 2-isoxazolin-5-ones in murine and human tumors

The 3,5-isoxazolidinediones and 2-isoxazolin-5-ones demonstrated potent cytotoxicity against the growth of human Tmolt3 T cell leukemia, murine P388 and L1210 leukemias, as well as human HeLa-S3 uterine carcinoma and glioma tumor cell growth. The specificity of the 3,5-isoxazolidinedione and 2-isoxazoline-5-one derivatives as cytotoxic agents varied with the histological type of tumor cell. Selected compounds were active against solid HeLa uterine. KB nasopharynx, skin A431, SW-480 adenocarcinoma, osteosarcoma and glioma growth. Selected compounds demonstrated in vivo antineoplastic activity against Ehrlich ascites carcinoma growth. In L-1210 leukemia cells, the agents blocked DNA and protein synthesis at 25, 50 and 100 microM over 60 min. The agents were effective in reducing rate limiting enzymes in the de novo purine and pyrimidine pathways. In addition they suppressed dihydrofolate reductase and ribonucleoside reductase activities with moderate inhibition of DNA and RNA polymerase activities. DNA itself was not a target of the agents.

In vitro assessment of oral delivery for hexapeptide endothelin antagonists

Endothelin (ET-1) is a 21-amino acid, vasoconstrictive peptide originally isolated from endothelial cells. It is one member of a class of potent, purportedly paracrine substances that act at receptors in multiple target organs. Antagonists to the receptor subtypes, ETA and ETB, have been designed around the hydrophobic carboxy-terminus of ET-1. The resulting hexapeptides possess low nanomolar receptor affinity, but face formidable challenges to oral delivery, given their peptidic nature. Hence, it was important to discriminate between analogs, as well as to optimize structural features combining binding potency with stability in intestinal fluids and permeability across biological membranes. PD 142893 (Ac-DDip16-Leu-Asp-Ile-Trp21) and PD 145065 (Ac-DBhg16-Leu-Asp-Ile-Ile-Trp21), as well as the N-methyl-isoleucine20 analogs were studies, where DDip = 3,3diphenylalanine and DBhg = 10,11-dihydro-5H-dibenzo[a,d]cycloheptene glycine. Analyses were conducted with specific HPLC methods. Permeabilities across CACO-2 cell monolayers ranged from 2.0x10(-4) to 6.3x10(-4)cm/min. The results suggested that these compounds can be absorbed in vivo, based on comparison of permeabilities with those obtained with reference compounds. Much greater differences were observed between the analogs when stability half-lives were compared after incubation in rat intestinal perfusate. The parent peptides, PD 142893 and PD 145065, were unstable, with half-lives less than 20 min. N-Methylation of Ile20 resulted in large increases in stability half-lives to greater 500 min. Enzyme inhibition studies demonstrated the involvement of carboxypeptidase A in production of the primary metabolite, the des-Trp derivative. Identification of the primary metabolite of the parent peptide was made by differential UV scanning at 214/280 nm and mass spectral analyses.

Anti-inflammatory activity of 2,3-dihydrophthalazine-1,4-diones in CF1 mice

2,3-Dihydrophthalazine-1,4-diones were observed to be potent anti-inflammatory agents as well as capable of protecting against endotoxin shock in mice at 8 mg/kg i.p. These agents blocked both locally- and centrally-induced pain at 8 mg/kg i.p. In part they appear to mediate their effects due to their ability to suppress the release of cytokines such as TNF alpha and IL-1 from macrophages, as well as the binding of these cytokines to high-affinity receptors on target cells involved in the inflammation process. Lysosomal hydrolytic enzymes as well as 5'-lipoxygenase activities were reduced by the agents.

The anti-inflammatory activity of N-substituted indazolones in mice

N-Substituted indazolones were shown to be potent anti-inflammatory and analgesic agents in mice at 8 mg/kg. In addition, the agents were able to protect against death caused by endotoxins similar to those found in chronic infections. In part, the ability of these agents to suppress the inflammatory process is due to their blockage of cytokine release, e.g.TNF alpha and IL-1, as well as their inhibition of high affinity binding to receptors on target cells of inflammation. Suppressing these receptors can be linked to the inhibition by the agents of lysosomal hydrolytic enzymes, prostaglandin cyclooxygenase and 5'-lipoxygenase activities. Free radical generation involved in inflammation was also stabilized in the presence of most of these agents.

Anti-inflammatory and analgesic activities of 3-imino-1-oxoisoindolines in CF1 mice

A series of 3-imino-1-oxoisoindolines were shown to be potent anti-inflammatory and analgesic agents at 8 mg/kg, intraperitoneally in mice. The compounds were also able to protect against lipopolysaccharide induced endotoxic shock and death better than the current clinical agents. These agents appear to function by blocking the release of TNF alpha and IL-1 from macrophages as well as competition with their respective high affinity receptors on target tissue, eg. fibroblasts, and macrophages. In addition lysosomal hydrolytic enzymes were inhibited as well as leukotriene synthesis in macrophages by the agents.

Transitional cell carcinoma of the renal pelvis metastatic to the metacarpal. A case report correlating cytologic and histologic findings

This report describes the cytologic, radiologic and histologic findings in a 76-year-old male who presented with a pathologic fracture of the first metacarpal bone as the result of metastatic transitional cell carcinoma. The primary neoplasm was sited in the right renal pelvis. Metastases were also detected in the liver and confirmed cytologically. Problems encountered with the cytologic diagnosis are explained by correlation with the histologic findings. The case also illustrates the importance of clinicopathologic correlation when interpreting fine needle aspiration biopsies.

Interaction of berberine with human platelet alpha 2 adrenoceptors

Berberine, an alkaloid, has been found to have a myriad of pharmacological effects including hypotensive, antisecretory, sedative, and antimicrobial effects, some of which are similar to those of clonidine, an alpha 2 adrenoceptor partial agonist. The interaction of berberine with human platelet alpha 2 adrenoceptor was investigated in this study. Berberine was found to inhibit competitively the specific binding of [3H]-yohimbine. The displacement curve was parallel to those of clonidine, epinephrine, norepinephrine, with the rank order of potency (IC50) being clonidine (0.4 microM) greater than epinephrine (7.5 microM) greater than norepinephrine (14.5 microM) = berberine (16.6 microM). Increasing concentrations of berberine from 0.1 microM to 10 microM inhibited [3H]-yohimbine binding, shifting the saturation binding curve to the right without decreasing the maximum binding capacity. In platelet cyclic AMP accumulation experiments, berberine at concentrations of 0.1 microM to 0.1 mM inhibited the cAMP accumulation induced by 10 microM prostaglandin E1 in a dose dependent manner, acting as an alpha 2 adrenoceptor agonist. In the presence of L-epinephrine, berberine blocked the inhibitory effect of L-epinephrine behaving as an alpha 2 adrenoceptor antagonist. These properties are similar to those of clonidine on human platelets, suggesting that berberine is a partial agonist of platelet alpha 2 adrenoceptors. These findings may provide potential mechanisms for the hypotensive, antisecretory, and sedative effects of berberine.

Iron overload in Chinese patients with hemoglobin H disease

We examined the iron status of 23 adult patients with hemoglobin H (Hb H) disease. None of them had received multiple blood transfusions or prolonged iron therapy. Studies included serum iron and ferritin concentrations, transferrin saturation, a desferrioxamine test, computed tomography (CT) scan of the liver, and liver biopsy. Iron overload was found in 17 patients (73.9%), especially in males and in patients with splenomegaly (92.9% and 100%, respectively). Four patients with excessive alcohol consumption had clinical manifestations of severe iron overload. Idiopathic hemochromatosis associated HLA antigens, i.e., HLA-A3, -B7, or -B14, were not found in any of the 15 patients tested. These findings indicate that iron overload is common in adult patients with Hb H disease; such patients should abstain from alcohol and be considered for treatment with an iron chelating agent before irreversible organ damage occurs.

Cardioprotective actions of nisoldipine in postreperfusion myocardial ischemia

Nisoldipine, a dihydropyridine with calcium channel-blocking activity, was studied in myocardial ischemia and reperfusion in cats. At an infusion rate of 3 micrograms/kg/hr, nisoldipine did not significantly alter the product of mean arterial blood pressure and heart rate, the pressure-rate index. When infusion of nisoldipine was started 30 minutes after occlusion and continued for 5 1/2 hours, nisoldipine exerted a marked antiischemic effect. This effect was manifested as a significant reduction in necrotic myocardial tissue expressed either as a percentage of area at risk (p less than 0.01) or as a percentage of total left ventricle (p less than 0.01). The washout of creatine kinase into the circulation was also reduced in nisoldipine-treated cats. When nisoldipine infusion started at 60 minutes after ischemia, the effects were still significant (p less than 0.05) but less striking, and when nisoldipine infusion was delayed until 90 minutes after ischemia, no significant cardioprotection was observed. Nisoldipine also blunted the washout of creatine kinase into the peripheral circulation on reperfusion. Thus nisoldipine exerts a cardioprotective effect in cats during myocardial ischemia independent of reducing myocardial oxygen demand. The effect is optimal when nisoldipine is given during the first 30 minutes of ischemia and declines thereafter, reaching insignificant effects at 90 minutes.

The effects of tetramethylpyrazine on the human platelet alpha 2 adrenergic receptor adenylate cyclase system

The binding properties of tetramethylpyrazine (TMPZ), a commonly used cardiovascular drug in China, to alpha 2 adrenergic receptors in human platelets were investigated. Increasing concentrations of TMPZ inhibited [3H]-yohimbine binding in intact platelets. The displacement curve was parallel to those of clonidine and yohimbine, with a Ki of 7.7 X 10(-5) M and an IC50 of 1.2 X 10(-4) M. In platelet membranes, increasing concentrations of TMPZ shifted the saturation binding curves of [3H]-yohimbine to the right and caused the dissociation constant (KD) to increase gradually. Higher concentrations of [3H]-yohimbine overcame the inhibition of TMPZ. Furthermore, in platelet cyclic AMP generation experiments, higher concentrations of TMPZ (10(-4)M-10(-6)M) inhibited the cyclic AMP increases induced by 10(-5) M PGE1. However, in the presence of an alpha 2 adrenergic receptor agonist (L-epinephrine), TMPZ blocked the inhibitory effect of L-epinephrine on cyclic AMP increases induced by PGE1. These properties suggested that TMPZ is an alpha 2 adrenergic receptor partial agonist. These effects may provide potential mechanisms for the cardiovascular actions of TMPZ.