Measurement of the 2νββ Decay Rate and Spectral Shape of ^{100}Mo from the CUPID-Mo Experiment

Neutrinoless double beta decay (0νββ) is a yet unobserved nuclear process that would demonstrate Lepton number violation, a clear evidence of beyond standard model physics. The process two neutrino double beta decay (2νββ) is allowed by the standard model and has been measured in numerous experiments. In this Letter, we report a measurement of 2νββ decay half-life of ^{100}Mo to the ground state of ^{100}Ru of [7.07±0.02(stat)±0.11(syst)]×10^{18}  yr by the CUPID-Mo experiment. With a relative precision of ±1.6% this is the most precise measurement to date of a 2νββ decay rate in ^{100}Mo. In addition, we constrain higher-order corrections to the spectral shape, which provides complementary nuclear structure information. We report a novel measurement of the shape factor ξ_{3,1}=0.45±0.03(stat)±0.05(syst) based on a constraint on the ratio of higher-order terms from theory, which can be reliably calculated. This is compared to theoretical predictions for different nuclear models. We also extract the first value for the effective axial vector coupling constant obtained from a spectral shape study of 2νββ decay.

Radiation protection for healthcare professionals working in catheterisation laboratories during pregnancy: a statement of the European Association of Percutaneous Cardiovascular Interventions (EAPCI) in collaboration with the European Heart Rhythm Association (EHRA), the European Association of Cardiovascular Imaging (EACVI), the ESC Regulatory Affairs Committee and Women as One

The European Association of Percutaneous Cardiovascular Interventions (EAPCI), the European Heart Rhythm Association (EHRA), the European Association of Cardiovascular Imaging (EACVI), the European Society of Cardiology (ESC) Regulatory Affairs Committee and Women as One support continuous review and improvement, not only in the practice of assuring patients a high quality of care but also in providing health professionals with support documents to help them in their career and enhance gender equity. Recent surveys have revealed that radiation exposure is commonly reported as the primary barrier for women pursuing a career in interventional cardiology or cardiac electrophysiology (EP). The fear of foetal exposure to radiation during pregnancy may lead to a prolonged interruption in their career. Accordingly, this joint statement aims to provide a clear statement on radiation risk and the existing data on the experience of radiation-exposed cardiologists who continue to work in catheterisation laboratories (cath labs) throughout their pregnancies. In order to reduce the barrier preventing women from accessing these careers, increased knowledge in the community is warranted. Finally, by going beyond simple observations and review of the literature, our document suggests proposals for improving workplace safety and for encouraging equity.

Prognostic implications of left ventricular systolic dysfunction in patients with spontaneous coronary artery dissection

AIMS

Spontaneous coronary artery dissection (SCAD) is a relatively infrequent cause of acute coronary syndrome. Clinical features, angiographic findings, management, and outcomes of SCAD patients who present reduced left ventricular ejection fraction (LVEF) remain unknown.

METHODS AND RESULTS

The Spanish multicentre prospective SCAD registry (NCT03607981), included 389 consecutive patients with SCAD. In 348 of these patients, LVEF could be assessed by echocardiography during the index admission. Characteristics and outcomes of patients with preserved LVEF (LVEF ≥50%, n = 295, 85%) were compared with those with reduced LVEF (LVEF <50%, n = 53, 15%). Mean age was 54 years and 90% of patients in both groups were women. The most frequent clinical presentation in patients with reduced LVEF was ST-segment elevation myocardial infarction (STEMI) (62% vs. 36%, P < 0.001), especially anterior STEMI. Proximal coronary segment and multi-segment involvement were also significantly more frequent in these patients. No differences were found on initial revascularization between groups. Patients with reduced LVEF significantly received more often neurohormonal antagonist therapy, and less frequently aspirin. In-hospital events were more frequent in these patients (13% vs. 5%, P = 0.01), with higher rates of death, cardiogenic shock, ventricular arrhythmia, and stroke. During a median follow-up of 28 months, the occurrence of a combined adverse event did not statistically differ between the two groups (19% vs. 12%, P = 0.13). However, patients with reduced LVEF had higher mortality (9% vs. 0.7%, P < 0.001) and readmission rates for heart failure (HF) (4% vs. 0.3%, P = 0.01).

CONCLUSION

Patients with SCAD and reduced LVEF show differences in clinical characteristics and angiographic findings compared with SCAD patients with preserved LVEF. Although these patients receive specific medications at discharge, they had higher mortality and readmission rates for HF during follow-up.

Procedural Results and One-Year Clinical Outcomes of Treatment of Bioresorbable Vascular Scaffolds Restenosis (from the RIBS VII Prospective Study)

Currently, both drug-eluting stents (DES) and drug-eluting balloons are recommended in patients with in-stent restenosis (ISR) of metallic stents. However, the clinical results of repeated interventions in patients with restenosis of bioresorbable vascular scaffolds (BVS) remain unsettled. We sought to assess the results of interventions in patients with BVS-ISR as compared with those obtained in patients with ISR of DES and bare-metal stents (BMS). Restenosis Intrastent: Treatment of Bioresorbable Vascular Scaffolds Restenosis (RIBS VII) is a prospective multicenter study (23 Spanish sites) that included 117 consecutive patients treated for BVS-ISR. Inclusion/exclusion criteria were similar to those of previous RIBS studies. Patients in the RIBS IV (DES-ISR, n = 309) and RIBS V (BMS - ISR, n = 189) randomized trials, were used as controls. Most patients with BVS-ISR were treated with DES (76%). Patients with BVS-ISR were younger, had larger vessels, and after interventions had higher in-segment residual diameter stenosis (19 ± 13%, 15 ± 11%, 15 ± 12%, p <0.001) than those treated for DES-ISR and BMS-ISR, respectively. At 1-year clinical follow-up (obtained in 100% of patients) target lesion revascularization (6%) was similar to that seen in patients with DES-ISR and BMS-ISR (8.7% and 3.7%, p = 0.32). Freedom from death, myocardial infarction, and target vessel revascularization (primary clinical end point) was 8.5%, also similar to that found in patients with DES-ISR and BMS-ISR (14.2% and 7.4%, p = 0.09). Results were also similar when only patients treated with DES in each group were compared and remained unchanged after adjusting for potential confounders in baseline characteristics. Time to BVS-ISR did not influence angiographic or clinical results. This study demonstrates the safety and efficacy of coronary interventions for patients presenting with BVS-ISR. One-year clinical results in these patients are comparable to those seen in patients with ISR of metallic stents (ClinicalTrials.gov ID:NCT03167424).

Spontaneous Coronary Artery Dissection and Menopause

Spontaneous coronary artery dissection (SCAD) is a relatively rare but well-known cause of acute coronary syndrome in women. The role of sexual hormones has been related to the pathophysiology of SCAD. However, clinical features, angiographic findings, management and outcomes of SCAD women in relation to menopause status remain unknown. The Spanish multicenter prospective SCAD registry (NCT03607981), included 318 consecutive patients with SCAD. All coronary angiograms were analyzed in a centralized Corelab. In this substudy, 245 women were classified according to their menopause state (pre-menopausal and post-menopausal). In-hospital outcomes were analyzed: 148 patients (60.4%) were post-menopausal. These patients were older (57 [52 to 66] vs 49 [44 to 54] years, p <0.01) and had more often hypertension (49% vs 27%, p <0.01) and dyslipidemia (46% vs 25%, p <0.01). Post-menopausal women showed more often previous history of acute coronary syndrome, including previous SCAD (9% vs 3%, p = 0.046), and presented less frequently as ST-segment elevation myocardial infarction on admission, compared with premenopausal women (34% vs 49%, p = 0.014). On the other hand, premenopausal women showed more often proximal and multisegment involvement (24% vs 7%, and 32% vs 18%, respectively, both p <0.01). Post-menopausal women were more often managed conservatively (85% vs 71%, p <0.01) and presented less frequently left ventricular dysfunction (both, p <0.01). There were no differences between groups in terms of in-hospital stay or mortality, new acute myocardial infarction, unplanned coronary angiography or heart failure. In conclusion, post-menopausal women with SCAD show different clinical and angiographic characteristics compared with pre-menopausal SCAD patients. Initial treatment strategy was different between groups, though in-hospital outcomes did not significantly differ (NCT03607981).

New Limit for Neutrinoless Double-Beta Decay of ^{100}Mo from the CUPID-Mo Experiment

The CUPID-Mo experiment at the Laboratoire Souterrain de Modane (France) is a demonstrator for CUPID, the next-generation ton-scale bolometric 0νββ experiment. It consists of a 4.2 kg array of 20 enriched Li_{2}^{100}MoO_{4} scintillating bolometers to search for the lepton-number-violating process of 0νββ decay in ^{100}Mo. With more than one year of operation (^{100}Mo exposure of 1.17  kg×yr for physics data), no event in the region of interest and, hence, no evidence for 0νββ is observed. We report a new limit on the half-life of 0νββ decay in ^{100}Mo of T_{1/2}>1.5×10^{24}  yr at 90% C.I. The limit corresponds to an effective Majorana neutrino mass ⟨m_{ββ}⟩<(0.31-0.54)  eV, dependent on the nuclear matrix element in the light Majorana neutrino exchange interpretation.

Spontaneous coronary artery dissection in Spain: clinical and angiographic characteristics, management, and in-hospital events

INTRODUCTION AND OBJECTIVES

Spontaneous coronary artery dissection (SCAD) is an uncommon cause of acute coronary syndrome. The characteristics and in-hospital clinical course of patients with SCAD in Spain remain unknown.

METHODS

We present data from consecutive patients included in the national prospective SCAD registry. Angiographic analysis was performed in a centralized core laboratory.

RESULTS

Between June 2015 and April 2019, we included 318 patients with SCAD (358 lesions) from 31 centers. Median age was 53 years, and 88% were women. The most frequent presentation was non-ST-segment elevation acute myocardial infarction (53%). The most frequently involved artery was the left anterior descending coronary artery (44%), predominantly affecting the distal segments (39%) and secondary branches (54%). Most lesions (62%) appeared on angiography as intramural hematoma, without double lumen. Conservative management was selected as the initial approach in most patients (78%). During the index admission, 6% of patients had a major adverse event and 4 patients (1.3%) died. Independent predictors of adverse events were initial management with percutaneous coronary intervention (OR, 5.97; P=.004) and angiographic presentation as intramural hematoma (OR, 4.96; P=.028).

CONCLUSIONS

In Spain, SCAD affects mainly middle-aged women. In most patients, the initial management strategy was conservative with excellent in-hospital survival. Initial management with percutaneous coronary intervention and angiographic presentation as intramural hematoma were related to the presence of in-hospital adverse events. Registered at ClnicalTrials.gov (Identifier: NCT03607981).

Development of 100 Mo -containing scintillating bolometers for a high-sensitivity neutrinoless double-beta decay search

This paper reports on the development of a technology involving 100 Mo -enriched scintillating bolometers, compatible with the goals of CUPID, a proposed next-generation bolometric experiment to search for neutrinoless double-beta decay. Large mass ( ∼ 1 kg ), high optical quality, radiopure 100 Mo -containing zinc and lithium molybdate crystals have been produced and used to develop high performance single detector modules based on 0.2-0.4 kg scintillating bolometers. In particular, the energy resolution of the lithium molybdate detectors near the Q-value of the double-beta transition of 100 Mo (3034 keV) is 4-6 keV FWHM. The rejection of the α -induced dominant background above 2.6 MeV is better than 8 σ . Less than 10 μ Bq/kg activity of 232 Th ( 228 Th ) and 226 Ra in the crystals is ensured by boule recrystallization. The potential of 100 Mo -enriched scintillating bolometers to perform high sensitivity double-beta decay searches has been demonstrated with only 10 kg × d exposure: the two neutrino double-beta decay half-life of 100 Mo has been measured with the up-to-date highest accuracy as T 1 / 2 = [6.90 ± 0.15(stat.) ± 0.37(syst.)] × 10 18 years . Both crystallization and detector technologies favor lithium molybdate, which has been selected for the ongoing construction of the CUPID-0/Mo demonstrator, containing several kg of 100 Mo .

Symmetry Reduction in the Quantum Kagome Antiferromagnet Herbertsmithite

Employing complementary torque magnetometry and electron spin resonance on single crystals of herbertsmithite, the closest realization to date of a quantum kagome antiferromagnet featuring a spin-liquid ground state, we provide novel insight into different contributions to its magnetism. At low temperatures, two distinct types of defects with different magnetic couplings to the kagome spins are found. Surprisingly, their magnetic response contradicts the threefold symmetry of the ideal kagome lattice, suggesting the presence of a global structural distortion that may be related to the establishment of the spin-liquid ground state.

Role of hydration in contrast-induced nephropathy in patients who underwent primary percutaneous coronary intervention

To investigate the role of hydration to prevent contrast-induced nephropathy (CIN) in patients with ST-segment elevation myocardial infarction (STEMI) who underwent primary percutaneous coronary intervention (PPCI), we prospectively included 408 consecutive patients who were randomly assigned to receive either hydration with isotonic saline (1 ml/kg/h since the beginning of the procedure and for 24 hours after it: NS+ group) or not (NS- group). All patients received an iso-osmolar nonionic contrast medium. The primary end point was the development of CIN: ≥25% or ≥0.5 mg/dl increase in serum creatinine within 3 days after the procedure. CIN was observed in 14% of patients: 21% in the NS- group and 11% in the NS+ group (p=0.016). CIN was significantly associated with death (15.2% vs 2.8%; p<0.0001) and need for dialysis (13.4% vs 0%; p<0.0001). In multivariate analysis, the only predictors of CIN were hydration (OR=0.29 [0.14 to 0.66]; p=0.003) and the hemoglobin before the procedure (OR=0.69 [0.59 to 0.88]; p<0.0001). In conclusion, intravenous saline hydration during PPCI reduced the risk of CIN to 48%. Patients with CIN had increased mortality and need for dialysis. Given the higher incidence of CIN in emergent procedures, and its morbidity and mortality, preventive hydration should be mandatory in them unless contraindicated.

Guiding-catheter thrombectomy combined with distal protection during primary percutaneous coronary intervention of a saphenous vein graft

Primary percutaneous intervention of saphenous vein grafts is associated with a high risk of distal embolization and no reflow. We report a case of acute myocardial infarction with a large intragraft thrombus, successfully treated with a technique combining thrombectomy with a 6 Fr guiding catheter and distal protection with the FilterWire EZ.

A complicated spontaneous left main coronary artery dissection. Is the initial conservative management safe in asymptomatic patients?

Spontaneous coronary artery dissection (SCAD) is a rare cause of acute coronary syndrome. Knowledge of this condition is scarce and, at present, no consensus exists with regards to the aetiology, prognosis, and treatment. Among patients with SCAD, cases involving the left main (LM) and the left anterior descending (LAD) and circumflex (Cx) arteries bifurcation are even more exceptional. Furthermore, the treatment of asymptomatic patients with involvement of these major vessels poses a major challenge for the cardiologists and cardiac surgeons. We report a case of complicated spontaneous left main coronary artery dissection in which we question what is the best initial treatment in these asymptomatic patients: conservative or early aggressive.

Nitric oxide induces HIF-1α stabilization and expression of intestinal trefoil factor in the damaged rat jejunum and modulates ulcer healing

BACKGROUND

The induction of intestinal trefoil factor (ITF) has been reported to depend on hypoxia-inducible factor-1 (HIF-1). Nitric oxide modulates HIF-1 activity. The present study aims to analyze the role of nitric oxide in jejunum damage induced by indomethacin and its ability to modulate epithelial function through the expression of ITF.

METHODS

Rats received indomethacin (7.5 mg/kg, s.c., twice), and a time course analysis of damage was performed (24-96 h after the first administration). In these animals, the role of nitric oxide was analyzed by using 1400W, a selective iNOS activity inhibitor (5 mg/kg, i.p./day), on: (1) intestinal damage, (2) ulcer healing, (3) the presence of nitrated proteins in the jejunum and (4) the protein expression of inducible nitric oxide synthase (iNOS), HIF-1α and ITF.

RESULTS

Indomethacin induced damage in the jejunum that was apparent at 24 h and peaked at 48-72 h. An increase in iNOS, HIF-1α, ITF and nitrated proteins was observed in the injured jejunum. Immunoprecipitation of HIF-1α allowed determination of the nitration/nitrosylation of this protein by using nitrotyrosine and nitrocysteine antibodies. Blockade of iNOS activity did not significantly modify damage or iNOS expression, but did significantly impede ITF induction, HIF-1α stabilization and HIF-1α detection with antibodies against nitrated proteins. In parallel to these results, pre-treatment with 1400W delayed the healing of the ulcer provoked by indomethacin.

CONCLUSIONS

These results suggest that iNOS-derived NO is involved in HIF-1α stabilization, probably through S-nitrosylation, and ITF expression in goblet cells of the damaged jejunum of indomethacin-treated rats and mediates ulcer healing.

Comparison of iodixanol and ioversol for the prevention of contrast-induced nephropathy in diabetic patients after coronary angiography or angioplasty

INTRODUCTION AND OBJECTIVES

This study was designed to compare differences in the incidence of contrast-induced nephropathy (CIN) and changes in serum creatinine (SCr) level following iso-osmolar iodixanol or low-osmolar ioversol administration in diabetic patients undergoing coronary angiography, with or without percutaneous coronary intervention (PCI). A number of studies have indicated that iodixanol reduces the risk of CIN in patients with renal impairment, with or without diabetes. Diabetic patients may have some degree of renal dysfunction despite having a normal SCr level.

METHODS

The study included 250 consecutive diabetic patients undergoing coronary angiography with or without PCI. Those enrolled during the first 7 months of the study received ioversol and those enrolled during the following 11 months received iodixanol. The primary study endpoint was the incidence of CIN. Secondary objectives were to identify independent predictors of CIN and to determine the mean increase in SCr 72 hours after contrast injection.

RESULTS

The overall incidence of CIN was 5.6%. The incidence of CIN was significantly lower with iodixanol than with ioversol (2.5% vs. 8.3%, respectively; odds ratio [OR]=0.255; 95% confidence interval [CI], 0.068-0.952; P=.047). A low estimated glomerular filtration rate (60.8+/-29 mL/min per 1.73 m2 in those with CIN vs. 75.3+/-25 mL/min per 1.73 m2 in those without; OR=0.975; 95% CI, 0.952-0.997; P=.03) and ioversol use were independent predictors of CIN.

CONCLUSIONS

In diabetic patients undergoing diagnostic coronary angiography with or without PCI, the iso-osmolar contrast medium iodixanol was associated with a lower incidence of CIN than low-osmolar ioversol.

[Intracardiac echocardiography and percutaneous closure of atrial septal defects in adults]

INTRODUCTION AND OBJECTIVES

Today, the transcatheter treatment of atrial septal defects using an occluding device is a safe and effective therapeutic approach. Recently, intracardiac echocardiography has been developed as an alternative to transesophageal echocardiography for guiding these procedures. We describe our experience with intracardiac echocardiography during the percutaneous closure of atrial septal defects in adult patients.

METHODS

This retrospective study involved 52 patients with atrial septal defects (77% with an ostium secundum defect and 23% with patent foramen ovale) who underwent transcatheter closure using an Amplatzer device under intracardiac echocardiographic guidance and without the need for general anesthesia or orotracheal intubation. Clinical follow-up was carried out at 24 hours, and 6 and 12 months, and with transthoracic echocardiograhy at 24 hours and 6 months.

RESULTS

The procedure was successful in 51 (98%) of the 52 patients. No serious complication was recorded. Three patients suffered paroxysmal atrial fibrillation in the following weeks, which resolved with medical treatment. At 6 months, echocardiographic examination confirmed that there was no residual shunting across the atrial septum in any patient.

CONCLUSIONS

Intracardiac echocardiography provided accurate anatomical information about the atrial septum and other intracardiac structures. The technique's use during the transcatheter closure of atrial septal defects using an occluding device was straightforward. In addition, the procedure was less uncomfortable for patients than transesophageal echocardiography because there was no need for general anesthesia or orotracheal intubation.

Outbreak of infection with extended-spectrum beta-lactamase-producing Klebsiella pneumoniae in a Mexican hospital

Thirty-one strains of Klebsiella pneumoniae (including 10 duplicates) from 21 septicemic pediatric patients (age, <2 months) were studied during a 4-month period (June to October 1996) in which the fatality rate was 62% (13 of 21). These isolates identified by the API 20E system yielded the same biotype. Pulsed-field gel electrophoresis experiments revealed the same clone in 31 strains. The isolates were multidrug-resistant but were still susceptible to ciprofloxacin, imipenem, and cefoxitin. A 135-kb plasmid was harbored in all of the isolates. No transconjugants were obtained that were resistant to ampicillin, cefotaxime, tetracycline, or gentamicin. Isoelectric focusing for beta-lactamases was performed on all strains, and three bands with pIs of 5.4, 7.6, and 8.2 were obtained. Of these, the pI 8.2 beta-lactamase had an extended-spectrum beta-lactamase phenotype. PCR amplification of both TEM- and SHV-type genes was obtained. The sequence analysis of the SHV PCR product indicated a mutation corresponding to the SHV-5 beta-lactamase.

Studies on the in vitro phototoxicity of the antidiabetes drug glipizide

The phototoxic antidiabetes drug glipizide (1) is photolabile under aerobic conditions and UV-B light. Irradiation of a phosphate-buffered solution of 1 under oxygen atmosphere produces 4 photoproducts as well as singlet oxygen, which was detected by trapping it with 2,5-dimethylfuran and by the histidine test. The photochemistry of 1 involves cleavage of the sulfonamine and the sulfonamine-R bonds. Red blood cell lysis, photosensitized by glipizide and the products of its aerobic photolysis were demonstrated. The photohemolysis rate was lower for 1 than for its photoproducts. Inhibition of this process on addition of 1, 4-diazabicyclo[2.2.2]octane (DABCO), reduced glutathione (GSH), Vitamin C, sodium azide, superoxide dismutase, and a-tocopherol confirmed the possibility of singlet oxygen, superoxide ion and free radicals participation. Furthermore, in a lipid-photoperoxidation test with linoleic acid the in vitro phototoxicity of glipizide was also verified. A low decreasing cell viability of lymphocytes and neutrophils was observed.

Helicobacter pylori: characteristics, pathogenicity, detection methods and mode of transmission implicating foods and water

Helicobacter pylori is an organism involved in the pathogenesis of human active chronic gastritis, peptic and duodenal ulcer diseases and gastric cancer. This review article covers this emerging human pathogen in terms of its phenotypic and genotypic characteristics, methods for culturing, its role in gastric pathogenicity, evidence involving its mode of transmission, difficulty in its isolation and detection methodology. In terms of transmission, both foodborne and waterborne pathways have been speculated as the mode of transmission for H. pylori as the patterns of the infection are consistent with those from fecal-oral and oral-oral transmission. Therefore, it is important to also evaluate methods for the detection of H. pylori from specifically food products and water. The detection of this pathogen has proved difficult since changes in cell morphology, metabolism and growth patterns occur when H. pylori is exposed to different environmental stimuli. The development of a viable but non-culturable coccoid (VNC) form is observed. These VNC forms do not undergo cellular division and cannot be cultured by traditional methods, increasing the difficulty in their detection. Since both viability and virulence in the VNC form of H. pylori are retained, the examination of food products and water for these forms is critical. Current methods include filtration, immuno-separation (IMS), polymerase chain reaction (PCR), probe hybridization, immuno-staining, autoradiography and ATP bioluminescence.

[The interaction between corn and Burkholderia (Pseudomonas) cepacia]

Burkholderia (Pseudomonas) cepacia is a plant growth promoting rhizobacteria that could improve maize productivity. In this work we studied some properties of B. cepacia strain 0057 in relation to interaction with maize. Spermosphere effect, chemostatic response, indolic compounds and siderophores production were evaluated. We observed inhibitory effect on bacterial growth by maize seeds and their soluble extracts. Root exudates had positive chemiostatic effect. We founded indolic compounds production (20.1 micrograms/ml) and siderophore presence. We think that this microorganisms could improve maize production.

Cisplatin-induced apoptosis of HeLa cells. Effect of RNA and protein synthesis inhibitors, Ca2+ chelators and zinc

HeLa cells exposed to cisplatin undergo cell death, presenting morphological and biochemical characteristics typical of apoptosis. In this study we demonstrate that this process is independent of RNA and protein synthesis, since it was not inhibited by actinomycin D or cycloheximide. These substances induced apoptosis by themselves, suggesting an unidentified short-lived inhibitor. The presence of Ca2+ chelators (EDTA and EGTA) did not have effect in this process, excluding the participation of extracellular Ca2+ access. Finally, zinc ions inhibited the low molecular weight DNA degradation and the apoptotic bodies production, but not cell death. These results provide an insight into the mechanism of action of one of the most used antineoplastic drug.

Outline of the Human Retrovirus Registry: profile of a Puerto Rican HIV infected population

OBJECTIVE

To present the general socio-demographic profile, some risk related parameters and elements of the clinical spectrum of disease at presentation, of those HIV/AIDS patients enrolled in the Human Retrovirus Registry.

METHODS

This is a prospective longitudinal cohort study, which has been identifying since May 1992, adults or adolescents 18 years or older with AIDS or HIV infection at the time they present to our health care facilities: University Hospital Ramon Ruiz Arnau and the Bayamon Immunology Clinic. The present analysis include patients enrolled between May 1992 and December 1996 (n = 1520). The measurement instrument is a modular questionnaire which actually includes 237 variables including socio-demographic data, risk variables, lifestyle and affective parameters, clinical and immunological variables and therapeutic data.

RESULTS

The mean baseline age of the 1520 patients was 35.7 years of age. Most participants were male (77.7%) and Hispanic (98.8%). Forty-five percent (45.1%) of the population were single and only 21.9% were married; nevertheless, fifty-one percent (51.7%) indicated to have children. 70% reported to be unemployed. Injecting Drug Usage appears as the first exposure mode (54.3%), followed by heterosexual contact cases (25.71%) and by men having sex with men (12.9%). The study of other risk practices revealed a large proportion of patients smoking tobacco (65.6%) and using alcohol (49.5%). Based on the 1993 CDC definition, forty-seven percent (47%) of the subjects had a clinical or immunological criterion to be considered as an AIDS case at first presentation. Among all AIDS cases, 440 patients presented with clinical AIDS (61.7%%) and 274 persons were classified as AIDS due to low CD4 counts alone (38.3%%). The most common AIDS defining conditions were: Pneumocystis carinii pneumonia (n = 201, 28.1%), Candidiasis Esophageal (n = 123, 17.2%), Toxoplasmosis (n = 95, 13.3%), Wasting syndrome (n = 68, 9.5%), and Tuberculosis (n = 68, 10.3%).

CONCLUSIONS

The socio-demographic and risk profile of AIDS patients in the present study is representative of the Puerto Rican AIDS population with regards to gender, age distribution, and risk scenario groups. This study revealed that a wide spectrum of social and behavioral vulnerabilities are impacting this population. A large proportion of patients is arriving to the health care facilities at a late stage of disease. Further studies including data from follow-up interviews will help to assess changes in the expression and evolution of the disease.

Cytogenetic analysis of a human familial 15p+ marker chromosome

An extreme variant of a human 15p+ marker chromosome is described in a human family. The short arm of this variant is greatly enriched in ribosomal RNA genes, and there are up to three secondary constrictions potentially active for rRNA transcription. These sites are hypomethylated, whereas the rest of rDNA is highly methylated, as shown by the isoschizomer pair HpaII-MspI. This chromosome variant is similar to others previously described for chromosomes 14 and 22, but some differences have been found after C-banding and after treatments with AluI and Sau3AI.

Cryptic variants of acrocentric human chromosomes as analysed by restriction endonucleases

Ten phenotypically normal human individuals have been analysed by in situ treatments with restriction endonucleases in order to obtain a better characterization of some cryptic variants of acrocentric chromosomes. Treatments with AluI, NdeII and Sau3AI confirm the existence of two cryptic amplified regions on the short arms of both one chromosome 15 and one chromosome 22, in one female. These amplifications seem to be of different origin involving the nucleolar organizer region of chromosome 15 and the satellite of chromosome 22.

Longitudinal differentiation of the human Yq heterochromatin as revealed by the restriction enzyme TaqI

The restriction endonuclease TaqI cleaves DNA at TCGA sites which are very common in human satellite DNAs. However, this enzyme was not used successfully up to now to digest constitutive heterochromatin of human chromosomes, where those highly repetitive DNAs are preferentially located. In this work, we show that TaqI is able to cut and extract DNA from the major heterochromatic regions on chromosomes 1, 9, 15, and 16 which appear as unstained gaps. Yq heterochromatin displays moderate digestion along its entire length but a middle region can be distinguished which is usually more affected. Complete digestion of Yq heterochromatin can be achieved when this block has been previously undercondensed by treating cell cultures with the cytidine analog, 5-azacytidine. Thus, it may be deduced that some factors related to chromatin organization might be involved in the action of TaqI. These results come to reinforce previous data about heterogeneity of Yq heterochromatin, and allow us to subdivide it into three different regions according to their differential response to TaqI digestion.

Visualization of R-bands in human metaphase chromosomes by the restriction endonuclease MseI

Human metaphase chromosomes were treated with the restriction endonuclease MseI, which cuts DNA at TTAA sequences. This enzyme preferentially cuts and extracts DNA from G-bands and thus is the first restriction endonuclease allowing direct R-band visualization. Specific patterns ranging from R+C-like to C-like banding can be induced, depending on the concentration of the enzyme. At intermediate concentrations, only a subset of R-bands are produced, corresponding to GC-rich bands that are especially resistant to heat denaturation (so-called T-bands). These results suggest that compositional differences between chromosomal regions determine the different rates of cleavage by MseI, not only between R- and G-bands but also among different R-bands.