Prognostic biomarkers in the use of radium-223 in patients with metastatic castration-resistent prostate cancer

OBJECTIVES

This study aimed to establish basal biomarkers in patients with bone metastatic castration-resistant prostate cancer (mCRPC) treated with 223Ra to predict better overall survival (OS), and assess hematologic toxicity and treatment response.

MATERIALS AND METHODS

This was a retrospective multicenter study including 151 patients with mCRPC between 2013 and 2020. OS was assessed according to basal hemoglobin (Hb), prostate-specific antigen (PSA), and alkaline phosphatase (AP) values, the World Health Organization pain scale, the Eastern Cooperative Oncology Group (ECOG) performance status scale, the number of metastatic lesions on bone scintigraphy (BS), and the use of protective bone agents and the dose received. The grade of hematological toxicities was evaluated as well as treatment response based on changes in AP and pre- and post-treatment pain.

RESULTS

The median OS was 24 months (95% confidence interval 16.5-31). The OS in 70% of patients who received complete (5-6 doses) versus incomplete (1-4 doses) 223Ra treatment was 34.9 vs. 5.8 months, respectively, being longer in patients with lower PSA and AP values, Hb >13 g/dl, lesser bone metastasis on bone scan and with an ECOG 0-1. 52/151 patients (34%) died during follow-up. Pain reduced in nearly 70% of patients and 66% presented a reduction in AP values. Half of the patients presented mild and 5 % severe hematological adverse effects.

CONCLUSIONS

mCRPC patients treated with 223Ra with Hb values >13 g/mL, an ECOG 0-1, low AP values, PSA < 20 ng/mL and lesser bone metastasis on BS presented a better OS with an adequate safety profile.

Immigration-Related Trauma Associated With Metabolic Risk and Cognition in Hispanic and Latino Immigrant Populations

Recent immigrant and undocumented Hispanic/Latino adults in the United States (U.S.) are an underserved segment of the aging population. In this cross-sectional pilot study, we examined associations between self-reported stressors metabolic syndrome, emotional reactivity, and cognitive functioning in a heterogenous sample (N=80) of Hispanic/Latino adults (43.8% Central America; 43.8% South America; 7.5% Caribbean; mean years in the U.S.=18.1, SD=12.8). Participants (Meducation=10.2 years, SD=5.34; Mage=48.6 years, SD=12.3) underwent blood draw, anthropometrics and NIH-toolbox cognitive and behavioral measures. Linear regressions indicated that, elevated glucose was inversely associated with working memory (r=-.30), whereas higher HDL and controlled glucose were associated with better episodic memory (r=.27) and executive functioning (r=.32). Results further revealed associations between immigration-related trauma and elevated posttraumatic stress symptomatology. Implications for mental health and early detection of modifiable risk factors to promote healthy aging in vulnerable Hispanic/Latino immigrant populations are discussed.

Epigenetic inactivation of the autophagy-lysosomal system in appendix in Parkinson's disease

The gastrointestinal tract may be a site of origin for α-synuclein pathology in idiopathic Parkinson's disease (PD). Disruption of the autophagy-lysosome pathway (ALP) may contribute to α-synuclein aggregation. Here we examined epigenetic alterations in the ALP in the appendix by deep sequencing DNA methylation at 521 ALP genes. We identified aberrant methylation at 928 cytosines affecting 326 ALP genes in the appendix of individuals with PD and widespread hypermethylation that is also seen in the brain of individuals with PD. In mice, we find that DNA methylation changes at ALP genes induced by chronic gut inflammation are greatly exacerbated by α-synuclein pathology. DNA methylation changes at ALP genes induced by synucleinopathy are associated with the ALP abnormalities observed in the appendix of individuals with PD specifically involving lysosomal genes. Our work identifies epigenetic dysregulation of the ALP which may suggest a potential mechanism for accumulation of α-synuclein pathology in idiopathic PD.

Hemispheric asymmetry in the human brain and in Parkinson's disease is linked to divergent epigenetic patterns in neurons

BACKGROUND

Hemispheric asymmetry in neuronal processes is a fundamental feature of the human brain and drives symptom lateralization in Parkinson's disease (PD), but its molecular determinants are unknown. Here, we identify divergent epigenetic patterns involved in hemispheric asymmetry by profiling DNA methylation in isolated prefrontal cortex neurons from control and PD brain hemispheres. DNA methylation is fine-mapped at enhancers and promoters, genome-wide, by targeted bisulfite sequencing in two independent sample cohorts.

RESULTS

We find that neurons of the human prefrontal cortex exhibit hemispheric differences in DNA methylation. Hemispheric asymmetry in neuronal DNA methylation patterns is largely mediated by differential CpH methylation, and chromatin conformation analysis finds that it targets thousands of genes. With aging, there is a loss of hemispheric asymmetry in neuronal epigenomes, such that hemispheres epigenetically converge in late life. In neurons of PD patients, hemispheric asymmetry in DNA methylation is greater than in controls and involves many PD risk genes. Epigenetic, transcriptomic, and proteomic differences between PD hemispheres correspond to the lateralization of PD symptoms, with abnormalities being most prevalent in the hemisphere matched to side of symptom predominance. Hemispheric asymmetry and symptom lateralization in PD is linked to genes affecting neurodevelopment, immune activation, and synaptic transmission. PD patients with a long disease course have greater hemispheric asymmetry in neuronal epigenomes than those with a short disease course.

CONCLUSIONS

Hemispheric differences in DNA methylation patterns are prevalent in neurons and may affect the progression and symptoms of PD.

[Biological effect of controlled fluid hyperthermia on rabbit healthy bones]

Fluid hyperthermia has been used to treat various types of cancers, but its effects on bone have not been determined. The purpose of this prospective study was to show the structural and metabolic changes of bone exposed to fluid hyperthermia and the effects of the latter on bone healing. Thirty New Zealand rabbits were used, weighting 2.8-3.2 kg; they were divided into 9 groups and 3 subgroups. An osteotomy was performed in the mid third of the right femur and this segment was exposed to hyperthermia at 15, 20 and 25 degrees centigrade for 50, 60 and 70 minutes. A bone scan was performed every 4 weeks and X-rays were taken every week up to week 13. The post-hoc Tukey test was used for the statistical analysis. Differences were found in the concentration of chemicals at temperatures above 60 degrees for 20 minutes with statistical significance; bone healing was delayed and there was evidence of metabolic activity. We conclude that exposure to temperatures above 60 degrees for 20 minutes resulted in morphologic alterations in potassium, magnesium, sulfur and phosphorus, and delayed bone healing. These results are used as parameters for the treatment of bone tumors with fluid hyperthermia.

Diversification of hepatitis C viruses in South America reveals a novel genetic lineage

Hepatitis C virus (HCV) has high genomic variability and, since its discovery, at least six different types and an increasing number of sub-types have been reported. Genotype 1 is the most prevalent genotype found in South America. Recent phylogenetic analysis of strains isolated in Uruguay revealed the presence of a different genetic lineage from major sub-types 1a and 1b. In order to study if type 1 HCV strains circulating in the South American region can be associated with this genetic lineage, sequence data obtained from the 5' non-coding region from 6 type 1 patients from Chile, were compared with sequences obtained from 12 type 1 Uruguayan and 9 type 1 Brazilian patients as well as 17 different strains of all types isolated elsewhere. The phylogenetic analysis revealed the existence of type 1 strains of this novel genetic lineage in all South American countries studied, and indicates a diversification of HCV viruses in the South American region.

[Hepatitis C virus in a group of hematological and oncohematological patients]

BACKGROUND

Little information is available in Chile about hepatitis C virus (HCV) in hematological and oncohematological patients.

AIM

To evaluate the prevalence of hepatitis C virus markers in a group of hematological and oncohematological pediatric patients seen at Valdivia Regional Hospital.

PATIENTS AND METHODS

Antibodies against virus C, determined by ELISA and viral RNA, determined using RT-polymerase chain reaction, were measured in 54 blood samples from children with hematological diseases (34 with Acute Lymphoblastic Leukaemia, 4 with Hodgkin Diseases, 4 with Haemolytic Anemia, 5 with Sarcomas, 2 with Non-Hodgkin Lymphoma, 2 with Thrombocytopenic Purpura, 1 with an Ependimoma, one with a Wilms Tumor and 1 with a Von Willebrand Disease).

RESULTS

All samples were negative for antibodies against hepatitis C virus. Viral RNA was found in four children, all with a diagnosis of acute lymphoblastic leukemia and who received chemotherapy and multiple transfusions.

CONCLUSIONS

The prevalence of Viral RNA for hepatitis C virus in oncohematological patients in our study is high and associated with the use of chemotherapy and multiple transfusions.

Use of linear and multiple antigenic peptides in the immunodiagnosis of acute hepatitis A virus infection

The reactivities of two panels of anti-HAV human sera from geographically distinct areas (Chile and Spain) to synthetic peptides from the VP1, VP2 and VP3 hepatitis A virus capsid proteins were examined by an enzyme-linked immunosorbent assay (ELISA) procedure. Two and four branched multiple antigenic peptides (MAPs) and palmitoylated peptides were compared with free synthetic sequences for the detection of IgM anti-HAV antibodies in the two panels of human sera. Our results showed that acute hepatitis A patient sera recognized preferentially homogeneous two branched MAPs and palmitic acid conjugated peptides. The palmitoyl-derived VP3(110-121) peptide and the corresponding dimeric MAP were the most sensitive and appropriate for serological studies of HAV-infected patients by ELISA, sensitivity and specificity being higher than 90% and 95%, respectively. These peptide-based tests open up new avenues in the development of peptide-based immunosorbent assays for the detection of acute HAV disease.

[Current status of immunity to hepatitis A virus in various adult groups]

BACKGROUND

As sanitary and economic conditions improve, the prevalence of antibodies to hepatitis A is now significantly lower.

AIM

To evaluate the prevalence of hepatitis A virus antibodies in healthy Chilean adults.

MATERIAL AND METHODS

Antibodies to hepatitis A virus were measured, using a commercial ELISA assay, in 215 voluntary blood donors (163 male, aged 19 to 30 years old) and 295 medical students and health personnel (156 male, aged 19 to 39 years old), residing in Valdivia, Chile.

RESULTS

Antibodies against hepatitis A virus were found in 68.2% of the total sample (351/510). Ninety percent of flood donors and 54% of health personnel and students were positive (p < 0.01). Age specific prevalence in blood donors 19 to 22, 23 to 29 and 27 to 30 years old was 81.0%, 95.2% and 95.6% respectively. Among the same age groups in medical students, the prevalence was 47.9%, 53.2% and 61.9% respectively (p < 0.01).

CONCLUSIONS

This study indicates a reduction in the prevalence of hepatitis A virus antibodies among adults in Valdivia (Chile). Differences detected between individuals are probably related to different socioeconomic levels. Medical students have an increased risk for hepatitis A infections than the general population.

Sequence elements that contribute to the degradation of yeast G alpha

BACKGROUND

Gpa1 is the alpha subunit of the yeast G-protein that regulates signal transduction during mating. The stability of Galpha/Gpa1 is influenced by the ubiquitin-dependent N-end rule pathway, suggesting that the regulation of G alpha levels may be important for effective mating response and recovery.

RESULTS

The G alpha sequences that confer sensitivity to degradation by the N-end rule pathway were identified. The insertion of this degradation signal (G1-Deg) into the ordinarily stable Gpa2 protein conferred proteolytic targeting. We examined G alpha degradation under different conditions and found that it was efficiently degraded in haploid and diploid cells, but was stable if it was synthesized prior to expression of the N-end rule pathway. Interestingly, a specific mutation in G alpha that is believed to promote the GTP-bound form (N388K) caused accelerated degradation.

CONCLUSION

A region encompassing a putative effector-binding domain (G1-Deg) is required for G alpha degradation via the N-end rule pathway. Our studies have shown that G alpha is susceptible to proteolysis soon after synthesis. These results are in agreement with the idea that G alpha is more unstable in the GTP-bound form, which is the predominant state of monomeric/free G alpha soon after synthesis. It is likely that the signal transduced by Gbetagamma can be regulated by adjusting the levels of G alpha through proteolysis.

Rad23 links DNA repair to the ubiquitin/proteasome pathway

Rad23 is an evolutionarily conserved protein that is important for nucleotide excision repair. A regulatory role has been proposed for Rad23 because rad23 mutants are sensitive to ultraviolet light but are still capable of incising damaged DNA. Here we show that Rad23 interacts with the 26S proteasome through an amino-terminal ubiquitin-like domain (UbL[R23]). The carboxy terminus of Rad23 binds to the Rad4 DNA repair protein and creates a link between the DNA repair and proteasome pathways. The ultraviolet sensitivity caused by deletion of the UbL(R23) domain may therefore arise from its inability to interact with the proteasome. The fusion proteins glutathione S-transferase (GST)-Rad23 and Rad4-haemagglutinin (HA), and the proteasome subunits Cim3 and Cim5, cofractionate through consecutive chromatography steps. The ubiquitin-like domain of human Rad23 (UbL[HRB]) also interacts with the human proteasome. These results demonstrate that ubiquitin-like domains (UbLs) represent a new class of proteasome-interacting motifs.

Inhibin binding sites in bovine pituitary membranes

Membranes derived from bovine pituitary glands free of the neural lobe were used to investigate the presence of binding sites for inhibin, a glycoprotein produced by the ovarian granulosa cells capable of selectively suppressing FSH secretion from the pituitary gland. Optimal concentration of membranes (400 micrograms prot) and 125I-bovine inhibin (2 nM) were incubated in a medium containing 50 mM Tris-HCl pH 7.4, 0.01 M MgCl2 and BSA 0.01% in a final assay volume of 200 microliters at 37 degrees C for different time intervals. Non-specific binding was estimated using unlabelled inhibin in excess. The time course of specific 125I-bovine inhibin (2 nM) binding to bovine pituitary membranes is slow with 50% binding at approximately 20 min of incubation and reaching equilibrium at 90 min of incubation. The kinetic analysis shows an apparent pseudo first order association rate constant (Kob) equivalent to 4 x 10(-2) min-1. Following equilibrium with the tracer, a large excess of unlabelled inhibin (1.27 microM) was able to displace 84% of the specific binding within 120 min of incubation and 50% of the binding at approximately 40 min. The analysis under displacing conditions showed an apparent dissociation rate constant (K2) equals to 1.5 x 10(-2) min-1 and an apparent association rate constant (K1) equals to 1.3 x 10(9) M min-1. Thus, the estimation of the apparent kinetic equilibrium dissociation constant (Kd = K2/K2) of the binding of inhibin to bovine pituitary membranes was 1.2 nM. These results show for the first time the existence of bovine inhibin specific binding sites in bovine pituitary, and also that such a binding can take place in the absence of either gonadal and/or hypothalamic influences. They also contribute to the better understanding of the role of non-steroidal hormones such as inhibin, in the regulation of gonadotrophin secretion.

[Use of a specific DNA probe to confirm sickle cell anemia in a caucasian woman]

A specific DNA probe containing part of the structural B-globulin gene was used to confirm the diagnosis of sickle cell anemia in a caucasian woman. The patient's genomic DNA was digested with the restriction endonuclease Dde I, fractioned by agarose electrophoresis and Southern blotting. Molecular hybridization was performed with the DNA probe prepared by chemical labelling with photobiotin. The beta 8/beta 8 genotype rendered only 1 fragment of length 376 bp. Upon digestion with Dde I, the DNA of an individual with the normal genotype containing the enzyme recognition sequence at the site of sickle cell mutation, resulted in 2 fragments of 201 and 175 bp. The pedigree of the patient's caucasian family was studied by Hb electrophoresis. Four out of 7 brothers carried the sickle cell trait.

[Adrenal hyperplasia of late onset: optimization of therapy by measuring the circadian variation of serum 17-OH-progesterone]

A 19 yr-old female patient with the diagnosis of late onset adrenal hyperplasia was treated since age 15 with different glucocorticoid preparations and dosage schedules plus spironolactone. In spite of a very good response in terms of amelioration of their hirsutism she experienced cushingoid manifestations associated with adrenal suppression. To overcome these side effects the patient was placed on hydrocortisone 20 mg at 8 AM plus spironalactone 50 mg q.i.d. Cushingoid features vanished and response to cosyntropin (ACTH 250 ug i.m.) was reestablished. To better ascertain the effects of this treatment we studied the circadian variation in serum 17-OH progesterone after hydrocortisone was administered at 8 AM and compared it with circadian variations under basal conditions or after late-evening (11 PM) administration of hydrocortisone, 20 mg. The early morning administration of hydrocortisone was unable to prevent the nocturnal elevation of 17-OH-progesterone in spite of normal levels from 9.30 AM to 3 AM. This nocturnal peak was associated with a slightly blunted nocturnal elevation of serum cortisol. In contrast, the late evening administration of hydrocortisone was able to suppress 17-OH-progesterone to within normal levels during all day. Serum cortisol during late evening therapy was not different from that observed during early morning administration (12.2 +/- 13.1 vs 9.9 +/- 11.3 micrograms/dl, p = 0.53), yet the corresponding 17-OH-progesterone levels were much lower (0.8 +/- 0.6 vs 5.9 +/- 6.9 ng/ml). We conclude that individualization of therapy is essential in patients with late-onset adrenal hyperplasia.(ABSTRACT TRUNCATED AT 250 WORDS)