Reduced orbitofrontal grey matter volume in myocardial infarction with non-obstructive coronary arteries (MINOCA)

Background

Myocardial infarction with non-obstructive coronary arteries (MINOCA) is seen in 6–10% of patients presenting acutely with suspected myocardial infarction. Cardiac magnetic resonance imaging (CMR) can identify an underlying cause in ∼80% of patients. These patients are more likely to have a history of mental health illness or an emotional or stressful precipitant.

Grey matter volume can be quantified in various anatomical regions of the brain and has been shown to be altered in common mental health conditions such as anxiety, stress and depression.

This is the first prospective study investigating the acute structural brain, cardiac and psychological changes using MRI in patients with myocardial infarction with non-obstructive coronary arteries (MINOCA) within 14 days of presentation compared to STEMI control patients.

Methods

Patients meeting the 2017 ESC definition of MINOCA were prospectively recruited with STEMI control patients from February to December 2019. All participants underwent brain and comprehensive cardiac MRI, bloods and baseline psychological evaluation. We used voxel-based morphometry (VBM) to quantify grey matter volume and changes were compared between groups.

Results

54 patients were included in this interim analysis (39 MINOCA, 15 STEMI controls). Demographics were largely similar but MINOCA patients were more likely to have a history of self-reported mental health disease (36% v 7%, p 0.03) and had significantly higher baseline anxiety (8.4 v 5.3, p 0.01) scores on the HADS questionnaire. We found that control patients have significantly greater grey matter volume in the orbitofrontal cortex (OFC) compared to MINOCA patients (pFWE-corr 0.002). The orbitofrontal cortex is involved in emotional processing and implicated in anxiety and depression. However, there was no association between grey matter volume in any brain region and anxiety, depression or perceived stress scale scores.

Conclusion

Patients with MINOCA are more likely to have a history of mental health disease and have higher anxiety scores at presentation than STEMI controls. They have less grey matter volume in the orbitofrontal cortex compared to STEMI controls.

Reduced Grey Matter Volume in the OFC

Funding Acknowledgement

Type of funding source: Private grant(s) and/or Sponsorship. Main funding source(s): Rosetrees Trust; James Tudor Foundation

P5430Long term outcomes of patients receiving Implantable Cardioverter Defibrillators in a contemporary implant population in the Essex region of the UK

Introduction

Implantable cardioverter-defibrillators (ICD) reduce the risk of sudden cardiac death in patients who are at risk and amongst among heart failure (HF) patients with a reduced left ventricular ejection fraction (LVEF).

Objective

The aim of this study was to determine the differences in outcomes amongst patients in a contemporary ICD implant population based on primary or secondary indications and an ischaemic or non-ischaemic aetiology. The primary outcome was death or appropriate device therapy for a ventricular arrhythmia. The secondary outcome was inappropriate shock therapy.

Purpose

The study cohort included consecutive patients who had an ICD or CRT-D implanted at a high-volume regional referral centre in Essex between 2014 and 2015. The censor point for follow up was 31/12/2018. Cumulative incidences were analysed by the method of Kaplan–Meier and compared using the log-rank test. In addition, the relationship between several clinical variables were tested in a multivariate Cox model to predict long-term mortality and this is described with hazard ratios (HR) and 95% CI.

Results

407 patients who received ICD treatment were followed up for a mean of 50±4 months. 63% had an Ischaemic cardiomyopathy and 60% had a primary prevention indication. Majority were men (81.5%), mean LVEF was (31±11) and mean age (71±11). The incidence of appropriate ICD therapy at 1-year post ICD insertion was 6.8% in all patients. This was significantly higher in patients with a secondary prevention indication compared to primary prevention (11.7% v 3.6% p=0.015) but similar in ischaemic compared to non-ischaemic patients (7.8% v 5.2% p=0.46). 1.9% patients had an inappropriate shock at 1 year and between group rate was similar. Overall 8.1% of patients did not survive beyond 1-year post implant with a mean time to death of 5.6±3.6 months. The cumulative incidence of the primary end-point at 1 year was similar in ischaemic and non-Ischaemic patients (7.8% v 8.6%; HR: 1.04, 95% CI 0.7–1.5, p=0.83) but was significantly higher at the end of study period in patients with an ischaemic aetiology (32.4% v 21%; HR: 1.59, 95% CI: 1.1–2.4, p=0.024) (Fig.1). In an adjusted Cox Hazard model, appropriate ICD therapy at 1 year (HR: 0.28, 95% CI: 0.17–0.47, p<0.001) and a secondary indication for ICD treatment (HR: 0.47, 95% CI: 0.31–0.73, p=0.001) were strongly associated with long-term mortality.

Figure 1

Conclusions

Our study highlights outcomes in a long-term follow up of ICD patients and in light of the debate around the DANISH trial, we have shown that at 1 year, the benefit of ICD therapy is comparable in non-ischaemic compared to ischaemic cardiomyopathies. Moreover, patients who had an ICD implanted for secondary prevention had a 3-fold mortality benefit at 1 year and had a higher rate of death. Appropriate ICD therapy and a secondary prevention indication predicted long term mortality.

Geochemical stability of acid-generating pyrrhotite tailings 4 to 5 years after addition of oxygen-consuming organic covers

Oxygen-consuming organic covers can serve as a reactive barrier to minimize sulfide oxidation in acid-generating tailings but may lead to metal mobilization in surface oxidized layers. We evaluated changes in the bio-geochemical stability of acid-generating, Cu-Ni pyrrhotite tailings 4 to 5 years after addition of a 50 cm-thick or a 1 m-thick biosolid cover planted with energy crops. The original tailings (pH 2.5) were oxidized in the first 10 to 40 cm, and goethite was the dominant sink for Cu and Ni, the main metal contaminants in these tailings. Both covers increased pH, nutrient availability, microbial activity and diversity in the oxidized tailings, and led to a reduction of water-soluble Cu, Ni, Fe and Al after 4 to 5 years of application. Changes in pH, humidity, organic C content, and redox conditions resulted in partial dissolution of jarosite and gypsum below the cover but goethite apparently remained stable. Under both covers, total Ni decreased in the oxidized layer, indicating remobilization, but Cu was retained. Significant accumulation of Cu as Cu sulfide at the oxidized/unoxidized tailings interface was detected only under the 1 m-thick cover, suggesting that the thinner cover may not sufficiently decrease the oxidizing conditions to mitigate acid mine drainage. Migration of nitrate and P down to the unoxidized tailings was observed under both covers and raises the concern of continued sulfide oxidation in unoxidized tailings. Although the implementation of thinner covers is economically more sustainable than thick covers, our results indicate that further research is required to establish their long-term suitability and performance to prevent acid mine drainage.

Integrative review on the non-invasive management of lower urinary tract symptoms in men following treatments for pelvic malignancies

AIM

To develop a non-invasive management strategy for men with lower urinary tract symptoms (LUTS) after treatment for pelvic cancer, that is suitable for use in a primary healthcare context.

METHODS

PubMed literature searches of LUTS management in this patient group were carried out, together with obtaining a consensus of management strategies from a panel of authors for the management of LUTS from across the UK.

RESULTS

Data from 41 articles were investigated and collated. Clinical experience was sought from authors where there was no clinical evidence. The findings discussed in this paper confirm that LUTS after the cancer treatment can significantly impair men's quality of life. While many men recover from LUTS spontaneously over time, a significant proportion require long-term management. Despite the prevalence of LUTS, there is a lack of consensus on best management. This article offers a comprehensive treatment algorithm to manage patients with LUTS following pelvic cancer treatment.

CONCLUSION

Based on published research literature and clinical experience, recommendations are proposed for the standardisation of management strategies employed for men with LUTS after the pelvic cancer treatment. In addition to implementing the algorithm, understanding the rationale for the type and timing of LUTS management strategies is crucial for clinicians and patients.

Preliminary characterization and biological reduction of putative biogenic iron oxides (BIOS) from the Tonga-Kermadec Arc, southwest Pacific Ocean

Sediment samples were obtained from areas of diffuse hydrothermal venting along the seabed in the Tonga sector of the Tonga-Kermadec Arc, southwest Pacific Ocean. Sediments from Volcano 1 and Volcano 19 were analyzed by X-ray diffraction (XRD) and found to be composed primarily of the iron oxyhydroxide mineral, two-line ferrihydrite. XRD also suggested the possible presence of minor amounts of more ordered iron (hydr)oxides (including six-line ferrihydrite, goethite/lepidocrocite and magnetite) in the biogenic iron oxides (BIOS) from Volcano 1; however, Mössbauer spectroscopy failed to detect any mineral phases more crystalline than two-line ferrihydrite. The minerals were precipitated on the surfaces of abundant filamentous microbial structures. Morphologically, some of these structures were similar in appearance to the known iron-oxidizing genus Mariprofundus spp., suggesting that the sediments are composed of biogenic iron oxides. At Volcano 19, an areally extensive, active vent field, the microbial cells appeared to be responsible for the formation of cohesive chimney-like structures of iron oxyhydroxide, 2-3 m in height, whereas at Volcano 1, an older vent field, no chimney-like structures were apparent. Iron reduction of the sediment material (i.e. BIOS) by Shewanella putrefaciens CN32 was measured, in vitro, as the ratio of [total Fe(II)]:[total Fe]. From this parameter, reduction rates were calculated for Volcano 1 BIOS (0.0521 day(-1)), Volcano 19 BIOS (0.0473 day(-1)), and hydrous ferric oxide, a synthetic two-line ferrihydrite (0.0224 day(-1)). Sediments from both BIOS sites were more easily reduced than synthetic ferrihydrite, which suggests that the decrease in effective surface area of the minerals within the sediments (due to the presence of the organic component) does not inhibit subsequent microbial reduction. These results indicate that natural, marine BIOS are easily reduced in the presence of dissimilatory iron-reducing bacteria, and that the use of common synthetic iron minerals to model their reduction may lead to a significant underestimation of their biological reactivity.

Mixed-valence cytoplasmic iron granules are linked to anaerobic respiration

Intracellular granules containing ferric and ferrous iron formed in Shewanella putrefaciens CN32 during dissimilatory reduction of solid-phase ferric iron. It is the first in situ detection at high resolution (150 nm) of a mixed-valence metal particle residing within a prokaryotic cell. The relationship of the internal particles to Fe(III) reduction may indicate a respiratory role.

A blinded, randomized controlled trial of neo-adjuvant celecoxib in patients with early prostate cancer

4563

Background: Celecoxib inhibits tumorigenesis in many in vitro and in vivo models by anti-angiogenesis, induction of apoptosis, and inhibition of tumour cell proliferation and hypoxia. Methods: 45 cT1–2 prostate cancer patients were block randomized 2:1 to four weeks celecoxib 400mg b.d. or no drug prior to radical prostatectomy (RP). Tumour immunohistochemistry was performed for cell proliferation (Ki-67), angiogenesis (CD-31, VEGF, VEGF-R2), hypoxia (HIF-1), apoptosis (TUNEL), and COX-2. All scoring was performed blind by PS and a random 20% were validated blindly by an immunopathologist (SBF). In 19 patients (12 celecoxib-treated, 7 control), peri-operative peripheral zone biopsies were subjected to cDNA microarray analysis to identify differences in gene expression profiling (GEP) between the groups. Results: There was ‘substantial’ (kappa >0.6) or ‘almost perfect’ (kappa >0.8) inter-observer agreement in immunoscoring for all stains. Baseline scores were not significantly different between the celecoxib and control groups. In the celecoxib group, RP scores were significantly lower for Ki-67 (p = 0.036), and non-significantly lower for hypoxia (p = 0.15), KDR (p = 0.16), COX-2 (p = 0.19), microvessel density (p = 0.53), and VEGF (p = 0.83); tumour apoptosis was non-significantly higher (p = 0.26). MANOVA of the full model of stains showed that the difference between the two groups approached statistical significance (p = 0.058), and this was visualized with principal component analysis. GEP revealed that 76 genes were significantly differentially expressed between the celecoxib and control groups using uncorrected t-tests. In the celecoxib group, the tumour suppressor gene p73 and genes associated with protection against oxidative stress were significantly up-regulated; genes associated with cell adhesion were significantly down-regulated, consistent with a reduction in metastatic potential. Conclusions: Celecoxib appears to have marked anti-cancer effects on prostate tumours, most notably affecting cell cycle regulation, oxidative stress, and cell signalling. It may therefore be a promising agent in the management of prostate cancer and warrants further investigation.

No significant financial relationships to disclose.

European Collaborative Group on Prostate Brachytherapy: Preliminary Report in 1175 Patients

OBJECTIVE

To establish a multi-centre database of a large number of patients treated with brachytherapy across Europe.

METHODS

A total of 1175 patient files were registered in the database and the completeness of the data on these patients resulted in the majority being included in the analysis.

RESULTS

The database of patients treated with brachytherapy across Europe indicates that optimal patient selection for this procedure has been made, both in terms of outcome and side-effects, which will be subject of future analyses. This should enable refinement of the treatment choice and administration as well as provide useful guidance to other centres that want to establish this procedure for their patients. It will also set the ground for prospective studies.

CONCLUSIONS

The established database indicates that brachytherapy as a treatment option for prostate cancer is well established in many centres.

Validation of a flexible cystoscopy course

OBJECTIVE

To examine the instructional effectiveness of a course for nurses wishing to learn flexible cystoscopy, using a virtual reality flexible cystoscopy simulator to measure the outcome.

SUBJECTS AND METHODS

Fourteen urology nurse practitioners with no previous experience of cystoscopy were taught the basic techniques of flexible cystoscopy. They then had supervised group instruction during which they practised flexible cystoscopy on an inanimate latex model, and were taught how to handle the cystoscope, followed by unsupervised practice, including use of the virtual reality (VR) simulator (URO Mentor, Simbionix, Israel). They then undertook a cystoscopy task on the simulator; within the bladder there were 10 flags (numbered 1-10) at key positions. By visualizing and photographing each of the flags the subject would have visualized the entire bladder mucosa. The number of flags seen was thus used as a measure of how much of the bladder mucosa was examined. The VR simulator also measured the total procedure time. After a day of training the subjects were reassessed and the changes in performance evaluated. Subjects were also asked their opinion of the use of VR for flexible cystoscopy.

RESULTS

The median (range) time to complete the procedure before the course was 3.33 (2-5.5) min and the number of flags seen 7 (6-9). After the course, the median time decreased to 2.85 (1.5-4.42) min and the number of flags seen increased to 8 (6-9). The change in time was significant (P = 0.03) but the difference in the number of flags was not (P = 0.12). All 14 subjects enjoyed the use of VR for learning flexible cystoscopy; they all reported that they were more confident in handling a flexible cystoscope and in undertaking flexible cystoscopy.

CONCLUSION

The virtual reality simulator was an effecctive tool for teaching flexible cystoscopy.

Sorption of Fe (hydr)oxides to the surface of Shewanella putrefaciens: cell-bound fine-grained minerals are not always formed de novo

Shewanella putrefaciens, a gram-negative, facultative anaerobe, is active in the cycling of iron through its interaction with Fe (hydr)oxides in natural environments. Fine-grained Fe precipitates that are attached to the outer membranes of many gram-negative bacteria have most often been attributed to precipitation and growth of the mineral at the cell surface. Our study of the sorption of nonbiogenic Fe (hydr)oxides revealed, however, that large quantities of nanometer-scale ferrihydrite (hydrous ferric oxide), goethite (alpha-FeOOH), and hematite (alpha-Fe(2)O(3)) adhered to the cell surface. Attempts to separate suspensions of cells and minerals with an 80% glycerin cushion proved that the sorbed minerals were tightly attached to the bacteria. The interaction between minerals and cells resulted in the formation of mineral-cell aggregates, which increased biomass density and provided better sedimentation of mineral Fe compared to suspensions of minerals alone. Transmission electron microscopy observations of cells prepared by whole-mount, conventional embedding, and freeze-substitution methods confirmed the close association between cells and minerals and suggested that in some instances, the mineral crystals had even penetrated the outer membrane and peptidoglycan layers. Given the abundance of these mineral types in natural environments, the data suggest that not all naturally occurring cell surface-associated minerals are necessarily formed de novo on the cell wall.

A molecular approach to galactosemia

Classical galactosemia (G/G) is caused by the lack of galactose-1-phosphate uridyltransferase (GALT) activity. A more common clinical variant, Duarte/Classical (D/G) produces partial enzymatic impairment. Although neonatal death due to G/G galactosemia has been largely eliminated by population-based screening and intervention, long-term outcome in some is associated with impaired growth, ovarian failure, dyspraxic speech and neurologic deficits. At least 32 variants in the nucleotide sequence of the GALT gene have been identified and 9 have transferred impaired GALT activity to transformed cells in transfection experiments. We here define the prevalence and biochemical phenotype of two mutations. An A to G transition in exon 6 of the GALT gene converts a predicted glutamine at codon 188 to an arginine (Q188R), and introduces a new HpaII cut site into the gene which enables population screening by polymerase chain reaction. An A to G transition in exon 10 in the GALT gene produces a codon change converting an asparagine to aspartic acid at codon 314 (N314D) and adds an AVA II cut site. We screened a large population for the Q188R and N314D sequence changes to investigate the prevalence of Q188R in G/G galactosemia, the effect of homozygosity for Q188R on outcome, and the prevalence and biochemical phenotype of the N314D sequence change. We found that the Q188R mutation has a prevalence of 62% in a predominately Caucasian population of 107 patients with G/G galactosemia. Homozygosity for Q188R was associated with a poor clinical outcome in a subgroup of these patients. The N314D mutation is associated with the Duarte biochemical phenotype with extraordinary concordance.

Successful high dose therapy for relapsed mediastinal large B cell lymphoma following surgical repair of anterior chest wall defect

We describe a man with relapsed large B cell mediastinal lymphoma and associated infected large anterior chest wall defect who required high dose salvage therapy for his underlying disease. An initial mediastinotomy wound, associated with recurrent sepsis, had developed into an abscess, then fistula and eventually a large anterior chest wall defect. Safe use of salvage chemotherapy required reconstructive surgery consisting of a pedicled muscle flap. The subsequent high dose chemotherapy was carried out without complications and 15 months later the patient is alive and well.

Urine and plasma galactitol in patients with galactose-1-phosphate uridyltransferase deficiency galactosemia

Urinary excretion of galactitol was determined in 95 normals (N/N), 67 galactosemic (G/G), and 39 compound heterozygotes for the Duarte and galactosemia genotype (D/G). Galactitol excretion is age-dependent in both normal individuals and patients with classic galactosemia on lactose-restricted diets. In galactosemic patients who are homozygous for the Q188R mutation, urinary galactitol levels were fivefold to 10-fold higher than those of normal subjects of comparable age. All but a few patients with classic galactosemia with the Q188R mutation and another mutant G allele had urinary excretion comparable to the Q188R homozygous patients. African-American galactosemic patients with the S135L mutation of the galactose-1-phosphate uridyltransferase (GALT) gene also excreted abnormal quantities of galactitol. Most subjects with a Duarte allele and a G allele excrete normal amounts of the sugar alcohol. There is a correlation between galactitol excretion and red blood cell (RBC) galactose-1-phosphate (gal-1-P). Plasma galactitol was also elevated in galactosemic patients (3.4 to 23.2 micromol/L; undetectable in normal individuals). In contrast to the decrease in urinary galactitol with age, plasma levels remain in a narrow concentration range with no significant difference with age. Urine and plasma galactitol distinguish galactosemic patients from normals. In addition, urinary galactitol excretion may be an important parameter for the assessment of steady-state galactose metabolism in galactosemia.

Metal binding by Pseudomonas aeruginosa PAO1 is influenced by growth of the cells as a biofilm

The metal-binding properties of Pseudomonas aeruginosa PAO1 biofilms were investigated using four metals (Cu, Fe, Au, and La). All but one of the metals (i.e., Cu) were bound by the biofilms in amounts that were significantly greater than those bound by planktonically grown cells of the same strain. Lanthanum precipitation appeared to be limited to the base of the biofilms and was not promoted by a shift in lipopolysaccharide production by the cells.Key words: metal binding, biofilms, Gram-negative bacteria, bioremediation.

Metal binding by Pseudomonas aeruginosa PAO1 is influenced by growth of the cells as a biofilm

The metal-binding properties of Pseudomonas aeruginosa PAO1 biofilms were investigated using four metals (Cu, Fe, Au, and La). All but one of the metals (i.e., Cu) were bound by the biofilms in amounts that were significantly greater than those bound by planktonically grown cells of the same strain. Lanthanum precipitation appeared to be limited to the base of the biofilms and was not promoted by a shift in lipopolysaccharide production by the cells.

Effect of O-side-chain-lipopolysaccharide chemistry on metal binding

Pseudomonas aeruginosa PAO1 produces two chemically distinct types of lipopolysaccharides (LPSs), termed A-band LPS and B-band LPS. The A-band O-side chain is electroneutral at physiological pH, while the B-band O-side chain contains numerous negatively charged sites due to the presence of uronic acid residues in the repeat unit structure. Strain PAO1 (A+ B+) and three isogenic LPS mutants (A+ B-, A- B+, and A- B-) were studied to determine the contribution of the O-side-chain portion of LPS to metal binding by the surfaces of gram-negative cells. Transmission electron microscopy with energy-dispersive X-ray spectroscopy was used to locate and analyze sites of metal deposition, while atomic absorption spectrophotometry and inductively coupled plasma-mass spectrometry were used to perform bulk quantitation of bound metal. The results indicated that cells of all of the strains caused the precipitation of gold as intracellular, elemental crystals with a d-spacing of 2.43 A. This type of precipitation has not been reported previously for gram-negative cells and suggests that in the organisms studied gold binding is not a surface-mediated event. All four strains bound similar amounts of copper (0.213 to 0.222 micromol/mg [dry weight] of cells) at the cell surface, suggesting that the major surface metal-binding sites reside in portions of the LPS which are common to all strains (perhaps the phosphoryl groups in the core-lipid A region). However, significant differences were observed in the abilities of strains dps89 (A- B+) and AK1401 (A+ B-) to bind iron and lanthanum, respectively. Strain dps89 caused the precipitation of iron (1.623 micromol/mg [dry weight] of cells) as an amorphous mineral phase (possibly iron hydroxide) on the cell surface, while strain AK1401 nucleated precipitation of lanthanum (0.229 micromol/mg [dry weight] of cells) as apiculate, surface-associated crystals. Neither iron nor lanthanum precipitates were observed on the cells of other strains, which suggests that the combination of A-band LPS and B-band LPS produced by a cell may result in a cell surface which promotes the formation of metal-rich precipitates. We therefore propose that the negatively charged sites located in the O-side chains are not directly responsible for the binding of metallic ions; however, the B-band LPS molecule as a whole may contribute to overall cell surface properties which favor the precipitation of distinct metal-rich mineral phases.

Alcohol-related homicides committed by women

In this paper we use data derived from interviews with female homicide offenders either incarcerated or on parole in New York to examine those cases (N=35) that the respondents believed were related to their use of alcohol at the time of the homicide. We found four basic types of these homicides based on victim-offender relationships and the circumstances of the incidents. Women who committed each type of alcohol-related homicide reported a variety of motives for committing these acts. We also found that there were similarities and differences between the types, not only in terms of the kinds of motives reported but also in terms of the extent to which planning was involved. Likewise, there were similarities and differences between the different types of homicides regarding the type and amount of alcohol and other drugs used by respondents on the day of the incident, and regarding respondents' perceptions of the alcohol-relatedness of the events. The implications of our findings are discussed.

Androgen inhibition of vitellogenin gene expression in tilapia (Oreochromis niloticus)

Treatment of mature female tilapia (Oreochromis niloticus) with high levels of androgen (17 alpha-methyltestosterone, 17 alpha MT) results in a pronounced decline in plasma vitellogenin levels as determined by gel electrophoresis. Total RNA extracted from livers of treated fish and vehicle-injected controls was analyzed by Northern and slot blot hybridization using an oligonucleotide complementary to a sequence in the 3' end of tilapia vitellogenin mRNA. The probe revealed an mRNA of 6.5 kb in liver from the control mature female fish which was decreased by 85% by androgen treatment. As expected, estradiol (E2) treatment induced the 6.5-kb mRNA in mature male tilapia. The antiestrogen, tamoxifen, strongly decreased vitellogenin mRNA levels in mature females. Radioimmunoassay of serum from control and 17 alpha MT-treated female tilapia showed a marked reduction in serum E2 levels, from 11.4 +/- 2.6 ng/ml in controls to 2.2 +/- 0.13 ng/ml in treated fish. Tamoxifen, however, resulted in increased serum E2 levels, probably by blocking E2 negative feedback. The serum E2-lowering effect of 17 alpha MT suggests an inhibitory site of action on gonadotropin production at the hypothalamic-pituitary axis, possibly through an androgen receptor or through an estrogen receptor after local aromatization of 17 alpha MT.

Drugs and homicide by women

In this paper we use data derived from interviews with 215 female homicide offenders incarcerated or on parole in New York to examine their drug use prior to and at the time of the homicide, their victims' drug use, and their perceptions as to the drug-relatedness of the homicides. We found that about 7 out of 10 respondents had been regular users of some drug at some point in their lives prior to their incarceration, while over half had been addicted to a substance. Over one-third of the respondents who were present at the scene were "high" on a drug at the time, while about half of the victims of these homicides used drugs before the homicide. Almost two-thirds of the homicides committed by respondents who were present at the scene were perceived to be drug-related. Alcohol, crack, and powdered cocaine were the drugs most likely to be related to these homicides. The implications of our findings are discussed.

Galactosemia: a strategy to identify new biochemical phenotypes and molecular genotypes

We describe a stratagem for identifying new mutations in the galactose-1-phosphate uridyl transferase (GALT) gene. GALT enzyme activity and isoforms were defined in erythrocytes from probands and their first-degree relatives. If the biochemical phenotypes segregated in an autosomal recessive pattern, we screened for common mutations by using multiplex PCR and restriction endonuclease digestions. If common mutant alleles were not present, the 11 exons of the GALT gene were amplified by PCR, and variations from the normal nucleotide sequences were identified by SSCP. The suspected region(s) was then analyzed by direct DNA sequencing. We identified 86 mutant GALT alleles that reduced erythrocyte GALT activity. Seventy-five of these GALT genomes had abnormal SSCP patterns, of which 41 were sequenced, yielding 12 new and 21 previously reported, rare mutations. Among the novel group of 12 new mutations, an unusual biochemical phenotype was found in a family whose newborn proband has classical galactosemia. He had inherited two mutations in cis (N314D-E203K) from his father, whose GALT activity was near normal, and an additional GALT mutation in the splice-acceptor site of intron C (IVSC) from his mother. The substitution of a positively charged E203K mutation created a unique isoform-banding pattern. An asymptomatic sister's GALT genes carries three mutations (E203K-N314D/N314D) with eight distinct isoform bands. Surprisingly, her erythrocytes have normal GALT activity. We conclude that the synergism of pedigree, biochemical, SSCP, and direct GALT gene analyses is an efficient protocol for identifying new mutations and speculate that E203K and N314D codon changes produce intraallelic complementation when in cis.

Ulnar club-hand and constriction-ring syndrome

An infant presented with ulnar club hand and constriction ring syndrome involving all four limbs. The former abnormality was diagnosed by ultrasound at 23 weeks gestation. This association has not been previously described.

A common mutation associated with the Duarte galactosemia allele

The human cDNA and gene for galactose-1-phosphate uridyl transferase (GALT) have been cloned and sequenced. A prevalent mutation (Q188R) is known to cause classic galactosemia (G/G). G/G galactosemia has an incidence of 1/38,886 in 1,396,766 Georgia live-born infants, but a more common variant of galactosemia, Duarte, has an unknown incidence. The proposed Duarte biochemical phenotypes of GALT are as follows: D/N, D/D, and D/G, which have approximately 75%, 50%, and 25% of normal GALT activity respectively. In addition, the D allele has isoforms of its enzyme that have more acidic pI than normal. Here we systematically determine (a) the prevalence of an A-to-G transition at base pair 2744 of exon 10 in the GALT gene, transition that produces a codon change converting asparagine to aspartic acid at position 314 (N314D), and (b) the association of this mutation with the Duarte biochemical phenotype. The 2744G nucleotide change adds an AvaII (SinI) cut site, which was identified in PCR-amplified DNA. In 111 biochemically unphenotyped controls with no history of galactosemia, 13 N314D alleles were identified (prevalence 5.9%). In a prospective study, 40 D alleles were biochemically phenotyped, and 40 N314D alleles were found. By contrast, in 36 individuals known not to have the Duarte biochemical phenotype, no N314D alleles were found. We conclude that the N314D mutation is a common allele that probably causes the Duarte GALT biochemical phenotype and occurs in a predominantly Caucasian, nongalactosemic population, with a prevalence of 5.9%.

The effect of lowering faecal pH on the rate of proliferation of the normal colonic mucosa

Epidemiological and animal studies suggest that faecal pH may be a risk factor for colorectal cancer with low faecal pH associated with a lower incidence of the disease. The aim of this study was to determine whether faecal pH (or dietary fibre) affects the short-term risk factors for colon cancer. Sixty-nine normal volunteers were randomized into three equal groups (A-C). They provided food records, faecal specimens and submitted to rectal biopsy for thymidine labelling studies before and after a 2-week intervention. Group A received a placebo of fruit juice. Group B, approximately 3.0 g d-1 sodium sulphate in juice. Group C, 30 g d-1 supplementary dietary fibre as wheat bran in bread. Age, sex, weight, height and intake of macronutrients and minerals were similar in the groups prior to intervention. Faecal pH was similar for the three groups before and was reduced in Group B after intervention (P = 0.001) with a relative reduction of 0.5 pH units. The labelling index for the three groups was similar prior to intervention; after, it was lowest in Group B with a relative reduction of 0.5% points, although this difference was not statistically significant. The results thus do not support the hypothesis that an acidification of faecal pH leads to a reduction in risk markers for colon cancer.

Increased glucose transport by human fibroblasts with a heritable defect in insulin binding

Insulin and IGF-I binding and their regulation of hexose transport were evaluated in skin fibroblasts cultured from a family (Atl) whose proband had leprechaunism, hypoglycemia, and severe insulin resistance. High affinity insulin binding to proband Atl cells was absent, and partially, but equally, impaired in fibroblasts from his related parents. IGF-I binding to his cultured fibroblasts was within the normal range. Cells from proband Atl had insulin receptor mRNAs similar to control fibroblasts. 3-O-Methyl-D-glucose (OMG) transport by proband Atl was threefold higher than in control fibroblasts (37.7 v 7.6-11 nmol/mL/s) and was insulin-insensitive. Proband Atl fibroblasts had a threefold increase in the Vmax for OMG entry and a concomitant increase in the number of D-glucose-inhibitable cytochalasin B binding sites on their plasma membrane. Similar levels of glucose transporter mRNA were observed in control and proband Atl fibroblasts. These results suggest that fibroblasts from patient Atl have a genetically transmitted mutation in the alpha subunit of their insulin receptor. In the homozygous affected proband, this mutation impairs insulin binding and causes elevated, insulin-insensitive glucose transport. The dysfunction resulting from this mutation is similar to that introduced in Chinese hamster ovary cells by transfection with a truncated alpha subunit.

Effect of calcium supplementation on mucosal cell proliferation in high risk patients for colon cancer

Recent findings suggest that supplemental calcium could lower the abnormally high proliferation rate found in the colonic mucosa of subjects at high risk for colon cancer. In this double blind controlled study, this effect in volunteers previously operated upon for a colorectal adenocarcinoma was tested. Thirty subjects were randomised to receive either elemental calcium 1200 mg/day or a placebo. Mucosal proliferation was measured with tritiated thymidine labelling before and after the 30 day intervention period. Diets, faecal pH and the concentration of calcium and bile acids in the aqueous phase of feaces were also measured. Labelling index did not differ significantly in the two groups before intervention (placebo 4.0(2.4) v calcium 4.9(2.9), but the difference approached significance afterwards (4.4(2.4) v 6.5(3.4), p = 0.06). Individual changes occurring with intervention were tabulated and comparison of the means for the groups was not significant (delta = 0.3 vs delta = 1.8, p = 0.11). Calcium concentration, faecal pH and deoxycholic acid concentration increased in the calcium group (p = 0.02, 0.005 and 0.004 respectively). Calcium does not show any effect in decreasing colonic mucosal proliferation in this high risk group for colon cancer; it may increase faecal pH and the production of deoxycholic acid in the colon.

Molecular genetics of severe insulin resistance

Leprechaunism and type A diabetes represent inborn errors of insulin resistance whose phenotypes suggested causation by mutations in the insulin receptor gene. Cells cultured from patients with leprechaunism specifically lacked high-affinity insulin binding. Partial but different degrees of impairment were observed in cells cultured from first-degree relatives. Different mutations in the insulin receptor's alpha subunit were proposed in different families (Ark-1, Atl, Minn, Mount Sinai) based on phenotype, cellular insulin binding, and insulin receptor structure. Molecular cloning and sequencing of mutant insulin receptor cDNA from family Ark-1 confirmed that the proband inherited a maternal missense and a paternal nonsense mutation in the alpha subunit and was a compound heterozygote. The insulin receptor was immunologically present on the plasma membrane of fibroblasts cultured from patients Ark-1 and Atl but was markedly reduced in cells from patients Minn and Mount Sinai. In cells from patient Minn, but not from patient Mount Sinai, the decreased number of insulin receptors was associated with reduced insulin receptor mRNA. In two families with the less severe form of insulin resistance, type A diabetes, mutations altered post-translational processing of the insulin receptor molecule. At a cellular level, these mutations of the alpha subunit of the insulin receptor shared defective binding and impaired stimulation of sugar transport by insulin. In family Atl, however, glucose uptake was constitutively increased. Thus, genetic variation in the insulin receptor gene causes a spectrum of inherited insulin-resistant syndromes and altered cellular signaling.

Antibody-mediated suppression of grafted lymphoma. III. Evaluation of the role of thymic function, non-thymus-derived lymphocytes, macrophages, platelets, and polymorphonuclear leukocytes in syngeneic and allogeneic hosts

Syngeneic or allogeneic mice pretreated with sublethal whole-body irradiation were rendered incapable of suppressing the growth of grafted tumor cells sensitized with alloantibody. The growth of sensitized tumor cells was suppressed when they were mixed with donor effector cells from mice syngeneic or allogeneic to the recipients and then were inoculated in irradiated recipients. Three donor-host combinations were used to study the suppression of the murine lymphoma 6C3HED indigenous to C3H mice. These were C3H donor cells in C3H recipients, C57BL/6 donor cells in C3H recipients, or C57BL/6 donor cells in C57BL/6 recipients. In all three combinations, macrophages obtained from an inflammatory exudate, exudate lymphocytes not bearing theta antigen, and platelets were, in descending order of effectiveness, consistently active in restoring antibody-mediated suppression of tumor growth in irradiated hosts. Prior irradiation of the transferred lymphocytes somewhat diminished their effectiveness. Freeze-thawed or heat-killed macrophages (but not freeze-thawed platelets or lymphocytes) were effective in restoration. Peripheral blood mononuclear leukocytes and splenic lymphoid cells were not active in the recipients syngeneic to the donor cells but were acitve in recipients allogeneic to the donor cells. Polymorphonuclear leukocytes isolated from peripheral blood or an inflammatory exudate were not active. Intact thymic function seems unimportant since antibody-mediated suppression took place as effectively in thymectomized mice as in normal controls.