Pharmacokinetic-pharmacodynamic assessment of the ivermectin and abamectin nematodicidal interaction in cattle

In a context of nematodicidal resistance, anthelmintic combinations have emerged as a reliable pharmacological strategy to control gastrointestinal nematodes in grazing systems of livestock production. The current work evaluated the potential drug-drug interactions following the coadministration of two macrocyclic lactones (ML) ivermectin (IVM) and abamectin (ABM) to parasitized cattle using a pharmacokinetic/pharmacodynamic (PK/PD) approach. The kinetic behavior of both compounds administered either separately or coadministered was assessed and the therapeutic response of the combination was evaluated under different resistance scenarios. In the pharmacological trial, calves received a single subcutaneous (s.c.) injection of IVM (100 μg/Kg); a single s.c. injection of ABM (100 μg/Kg) or IVM + ABM (50 μg/Kg each) administered in different injection sites to reach a final ML dose of 100 μg/Kg (Farm 1). Plasma samples were taken from those animals up to 20 days post-treatment. IVM and ABM plasma concentrations were quantified by HPLC. A parasitological trial was carried out in three farms with different status of nematodes resistance to IVM. Experimental animals received IVM (200 μg/Kg), ABM (200 μg/Kg) or IVM + ABM (100 μg/Kg each) in Farm 2, and IVM + ABM (200 μg/Kg each) in Farms 3 and 4. The anthelmintic efficacy was determined by fecal egg count reduction test (FECRT). PK analysis showed similar trends for IVM kinetic behavior after coadministration with ABM. Conversely, the ABM elimination half-life was prolonged and the systemic exposure during the elimination phase was increased in the presence of IVM. Although IVM alone failed to control Cooperia spp., the combination IVM + ABM was the only treatment that achieved an efficacy higher than 95% against resistant Cooperia spp. in all farms. In fact, when Cooperia spp. was the main genus within the nematode population and Haemonchus spp. was susceptible or slightly resistant to ML (Farms 2 and 4), the total FECR for the combination IVM + ABM was higher than 90%. Instead, when the predominant nematode genus was a highly resistant Haemonchus spp. (Farm 3), the total FECR after the combined treatment was as low as the single treatments. Therefore, the rational use of these pharmacological tools should be mainly based on the knowledge of the epidemiology and the nematode susceptibility status in each cattle farm.

Successful pulp revascularization of an autotransplantated mature premolar with fragile fracture apicoectomy and plasma rich in growth factors: a 3-year follow-up

AIM

This case report demonstrates a positive outcome of the adjuvant use of fragile fracture (FF), which is a technique used to harvest dental pulp stem cells (DPSCs), and platelet-rich plasma (PRP) in a mandibular premolar (tooth 44) with a completely formed root that was transplanted into a surgically created socket and which maintained pulp vitality and function.

SUMMARY

After virtual surgical planning, a 3D tooth replica of tooth 44 was fabricated. A surgical socket was created in the position of tooth 14; then, tooth 44 was extracted and the root dentine was abraded using a turbine diamond bur 3 mm from the apex until a circular groove was prepared around the outer circumference of the root; and then, an FF was performed without damaging the pulp tissue. PRP was placed in the socket, after which the donor tooth was inserted in the recipient area. At 2 weeks post-treatment, orthodontic traction was applied. At 3-year follow-up, the tooth had adequate alignment and was asymptomatic. Response to pulp testing was positive, and the presence of pulp canal obliteration was observed as a sign of pulpal healing.

KEY LEARNING POINTS

Autotransplantation is a good alternative for replacing missing teeth, with repair of tissues and pulp revascularization. Revascularization of an autotransplanted mature tooth using the fragile fracture technique and PRP scaffold is a feasible option and might have positive effects on the long-term outcome of the procedure. Including completely formed teeth as donors in autotransplantation, maintaining vitality and their functions is an option that warrants further study.

OS5.1 Phase I clinical trial with oncolytic virus DNX-2401 for DIPGs

BACKGROUND

Despite our increased understanding of the genetic make-up and new therapies for pediatric high grade glioma (pHGG) and Diffuse Intrinsic Pontine Glioma (DIPG) the outcome remains grim. Delta-24-RGD (DNX-2401 in the clinic) has been tested for adult glioblastoma presenting a safe profile and promising efficacy. Recently our group has showed that the virus is safe and effective in preclinical models of pHGG and DIPG. Moreover, we showed that the virus is able to trigger an antitumor immune response. These outstanding preclinical results allowed us to propel a phase I clinical trial for newly diagnosed DIPGs (NCT03178032) where the patients received an intratumoral viral injection followed by standard radiotherapy.

MATERIALS AND METHODS

A phase I clinical trial with DNX-2401 for patients with newly diagnosed DIPG to assess the MTD is taking place in our hospital (N=12). Tumor biopsy is performed through the cerebellar peduncle, followed by virus injection. The virus is injected using a cannula, MEMS cannula (Alcyone Lifesciences) that prevents the reflux. Virus will be injected starting with 1010 pv. The trial is uncontrolled, unicentric with a 3 + 3 design. The objective of this trial is to determine the safety, tolerability, and toxicity of DNX-2401 in subjects with DIPG and to collect tumor samples of this type of tumor. Secondary endpoints are overall survival at 12 months (OS12), percentage of responses and induced immune response against tumor. The follow up includes close monitoring of neurological status, blood tests and brain MRI. If this trial shows evidence of safety and efficacy will propel a multicenter clinical trial.

RESULTS

All the clinical data from the trial available until September 2019 will be presented during the congress, to date 8 patients have been treated within the trial. Three patients were treated with the D1=1x1010vp and because the lack of toxicity we escalated to the D2= 5x1010vp. The procedure was well tolerated and safe. Patients were home 3–4 days after the injection. All the patients displayed a reduced tumor volume after combined treatment. We performed molecular studies in 6 out of the 8 patients. We are currently assessing the immune responses to the virus.

CONCLUSIONS

Information acquired within this clinical study would aid to understand the response of DIPGs to viral therapies and therefore to better tailor this strategy to improve the survival and the quality of life of pediatric brain tumors.

Pharmacokinetic assessment of the monepantel plus oxfendazole combined administration in dairy cows

Monepantel (MNP) is a novel anthelmintic compound launched into the veterinary pharmaceutical market. MNP is not licenced for use in dairy animals due to the prolonged elimination of its metabolite monepantel sulphone (MNPSO₂ ) into milk. The goal of this study was to evaluate the presence of potential in vivo drug-drug interactions affecting the pattern of milk excretion after the coadministration of the anthelmintics MNP and oxfendazole (OFZ) to lactating dairy cows. The concentrations of both parent drugs and their metabolites were measured in plasma and milk samples by HPLC. MNPSO₂ was the main metabolite recovered from plasma and milk after oral administration of MNP. A high distribution of MNPSO₂ into milk was observed. The milk-to-plasma ratio (M/P ratio) for this metabolite was equal to 6.75. Conversely, the M/P ratio of OFZ was 1.26. Plasma concentration profiles of MNP and MNPSO₂ were not modified in the presence of OFZ. The pattern of MNPSO₂ excretion into milk was also unchanged in animals receiving MNP plus OFZ. The percentage of the total administered dose recovered from milk was 0.09 ± 0.04% (MNP) and 2.79 ± 1.54% (MNPSO₂ ) after the administration of MNP alone and 0.06 ± 0.04% (MNP) and 2.34 ± 1.38% (MNPSO₂ ) after the combined treatment. The presence of MNP did not alter the plasma and milk disposition kinetics of OFZ. The concentrations of the metabolite fenbendazole sulphone tended to be slightly higher in the coadministered group. Although from a pharmacodynamic point of view the coadministration of MNP and OFZ may be a useful tool, the presence of OFZ did not modify the in vivo pharmacokinetic behaviour of MNP and therefore did not result in reduced milk concentrations of MNPSO₂ .

Meteorological variation effect on aerobiology--new tools on pollen forecasting

Spanish Aerobiology Network (REA) includes 22 research groups implied in the biological analysis of the air from 50 observation sites extended over the Iberian Peninsula and Baleares Islands. To offer in-advance information for pollen allergy sufferers, doctors and health authorities is one of REA priorities. One of our objectives is the study of the influence of meteorological variations on the quantity and occurrence of pollen in the atmosphere. Nevertheless, to include only weather parameters is not enough for build accurate forecasts. Field phenology data, vegetation land cover, topography data and previous aerobiological data should be included in the models. Meteorological conditions control the start, duration, intensity and end of the pollen season, but their effect depends on the different types of vegetation. The biological response of tree pollination is highly differentiated from the herbaceous one. Another important point is the adaptation of a given species phetnology to different climatic areas. We showed the different phenoclimatic variables determining tree flowering in the Mediterranean climate areas and in the Atlantic climate ones of the Iberian Peninsula, and the consequences on the development of our forecasting models. Finally we comment our more recent studies that use geostatistic algorithms as a tool for including all the cited parameters and also space variables as altitude, latitude and orientation to sun.

Sequence analysis and androgen regulation of MHG07 (Male harderian gland) mRNA in male hamster harderian gland

The hamster Harderian gland (HG), a compound tubuloalveolar gland located in the orbital cavity, displays sex dimorphism. The present study focuses on the sequence analysis of a cDNA clone named MHG07 and on the regulation of its expression by steroid hormones. MHG07 mRNA (5.0 kb) is expressed in male HG only. The MHG07 cDNA (1.74 kb) shows an ORF of 94 amino acids and has no significant homologies with other polypeptides/genes. Castration leads to the disappearance of MHG07 mRNA after 4 days, whereas treatment with testosterone impairs the effect of castration. No MHG07 mRNA has been found in either rat or murine HGs. Androgen (A) administration to female hamsters induces the appearance of MHG07 mRNA. In primary culture of male hamster HG, androgens increase the MHG07 expression and this effect is blocked by both flutamide and cycloheximide. Dose-response experiments show that, at low A concentration (10(-12) M), the MHG07 was higher than that of the control (2-fold). This effect reaches its zenith at 10(-8) M (10-fold). This picture is paralleled by androgen receptor mRNA expression. It is argued that the expression of MHG07 is under androgenic control.

Targeted disruption of the biglycan gene leads to an osteoporosis-like phenotype in mice

The resilience and strength of bone is due to the orderly mineralization of a specialized extracellular matrix (ECM) composed of type I collagen (90%) and a host of non-collagenous proteins that are, in general, also found in other tissues. Biglycan (encoded by the gene Bgn) is an ECM proteoglycan that is enriched in bone and other non-skeletal connective tissues. In vitro studies indicate that Bgn may function in connective tissue metabolism by binding to collagen fibrils and TGF-beta (refs 5,6), and may promote neuronal survival. To study the role of Bgn in vivo, we generated Bgn-deficient mice. Although apparently normal at birth, these mice display a phenotype characterized by a reduced growth rate and decreased bone mass due to the absence of Bgn. To our knowledge, this is the first report in which deficiency of a non-collagenous ECM protein leads to a skeletal phenotype that is marked by low bone mass that becomes more obvious with age. These mice may serve as an animal model to study the role of ECM proteins in osteoporosis.

Histopathologic prognostic score in colorectal adenocarcinomas

OBJECTIVE

To analyze the prognostic value of a set of pathological variables after curative resection for large bowel adenocarcinoma and to test a prognostic score derived from factors with independent effect.

PATIENTS AND METHODS

The study is based on data from 292 consecutive unselected patients (B-C Astler-Coller stages). Histopathological features were evaluated prospectively on the resected primary tumors. Relationship between these factors and risk of recurrence was assessed by a Cox's proportional regression analysis.

RESULTS

Four variables retained independent prognostic significance: extent of bowel wall invasion, peritumoral lymphocytic infiltration, number of positive nodes and vascular invasion. A prognostic score based on the regression coefficients attained by such variables was developed. This system revealed four prognostic groups. Group I included 14% of patients, with 94% 5-year disease-free survival. These figures were: 35% and 60% in group II; 43% and 46% in group III; and 7% and 24.4% in group IV. Histopathologic score applied to bearers of Astler-Coller B2 tumors permitted the identification of two populations, one characterized by a low risk of relapse and another with high risk (p = 0.002).

CONCLUSION

A prognostic score based in the evaluation of four histopathologic parameters concerning the tumor phenotype enables the identification of groups of patients at risk of relapse after curative resection for colorectal adenocarcinoma.

Clinical, virological, and histologic evolution of hepatitis C virus infection in liver transplant recipients

We designed a prospective study to assess the time course and evolution of hepatitis C virus (HCV) infection in 152 patients who underwent a liver transplantation (LT) in our institution. Forty-four recipients (29%) were infected by HCV after transplantation: 40 who developed recurrent infection after LT and four who acquired infection during or after LT. No differences were found in survival actuarial rates at 1, 2, and 4 years after transplantation for patients infected by HCV vs. noninfected ones. Graft hepatitis occurred in 66% of HCV-infected recipients: 18 developed chronic active hepatitis (10 of them with intense fibrosis) and 2 developed cirrhosis during the follow-up. Infection by the HCV-1b genotype was found in 79% of the infected recipients and in 100% of those in whom histologic evolution was worst. Fourteen grafts were lost in 44 HCV-infected recipients, in comparison with 12 in 108 HCV-negative patients (P = .007), mostly because of chronic rejection. HCV infection did not affect life expectancy in the midterm follow-up for LT patients. However, it was often associated with the occurrence of early and severe graft hepatitis and with a higher incidence of graft loss due to chronic rejection.

Antimitochondrial antibody-negative chronic nonsuppurative destructive cholangitis. Atypical primary biliary cirrhosis or autoimmune cholangitis?

We investigated whether autoimmune cholangitis (AC) has specific features that constitute an entity other than primary biliary cirrhosis (PBC). We compared clinical, laboratory, and liver biopsy features; response to treatment; and the follow-up of two groups of patients. The first group comprised seven patients with AC criteria-PBC with negative antimitochondrial antibodies (AMAs) and positive antinuclear antibodies (ANAs)-termed the PBC AMA-negative group; the second was made up of another seven PBC patients with positive AMA, labeled the PBC AMA-positive group. We found that the PBC AMA-negative group had, besides negative AMAs and positive ANAs, a significantly higher incidence of asthenia, a higher and earlier incidence of liver failure, and higher ANA titers and serum immunoglobulin G levels than the PBC AMA-positive group. There were no significant differences in the other laboratory tests, although the PBC AMA-negative group showed higher serum bilirubin and aminotransferase and lower serum alkaline phosphatase and immunoglobulin M levels. Liver histological data were similar in both groups. Patients in the PBC AMA-negative group, with more markedly abnormal liver tests, responded to immunosuppressive therapy. We concluded that patients with criteria for PBC but with negative AMAs and positive ANAs have a few specific features that fall between PBC and autoimmune chronic hepatitis. This finding suggests that these patients have a different disease, for which autoimmune cholangitis seems to be an appropriate name.

Effects of human chorionic gonadotropin and progesterone administration on porphyrin biosynthesis and histology of the Harderian glands in male and female Syrian hamsters

We investigated the influence of hCG and progesterone on the control of porphyrin biosynthesis and histology in the Syrian hamster Harderian glands. Castration of male hamsters caused a marked elevation in porphyrin biosynthesis as revealed by the concentrations of porphyrins and the mRNA levels of the porphyrin pathway rate-limiting enzyme, 5-aminolevulinate synthase (ALV-S). Injection of hCG into castrated male hamsters also resulted in a significant increase in both porphyrin concentrations and levels of ALV-S mRNA compared with those in saline-injected castrated hamsters. Type II cells, which are filled with large lipid vacuoles and are characteristic of male phenotype, disappeared after castration, but administration of hCG partially prevented this change. On the other hand, neither administration of hCG nor progesterone implants could increase the very high porphyrin concentrations and ALV-S mRNA levels characteristic of female Syrian hamsters. As in the case of castrated male hamsters, injections of 20 IU hCG to female Syrian hamsters increased the relative number of Type II cells per square millimeter, whereas progesterone administration did not modify the relative number of Type II cells. These results indicate that hCG can modify Harderian gland morphology in both male and female hamsters and can exert a positive control in the expression of ALV-S gene in castrated male hamsters.

Expression of the osteonectin gene potentially controlled by multiple cis- and trans-acting factors in cultured bone cells

The cis-acting regulatory elements of the osteonectin gene have been studied using a chloramphenicol acetyltransferase (CAT) promoter assay in osteonectin-expressing and nonexpressing cultured cells. When various stretches of the promoter were transiently transfected into fetal bovine bone cells, a positive element was detected in the DNA located between bases -504 and 11 (1 being the start of transcription) and a negative element between bases -900 and -504. The positive element of the promoter also conferred preferential expression of the gene, showing more activity in cells with higher levels of osteonectin mRNA expression. A 1.2 kb fragment of intron 1 displayed a negative effect on CAT expression when inserted 5' to the promoter. An additional regulatory element was found in DNA encoding exon 1, which significantly influenced expression of the gene in fetal bovine bone cells. Gel shift analysis using positive genomic elements located 5' to the start of transcription indicated that one of the nuclear proteins that interacts with the osteonectin promoter may be related to the transcription factor AP2.

5-aminolevulinate synthase mRNA levels in the Harderian gland of Syrian hamsters: correlation with porphyrin concentrations and regulation by androgens and melatonin

The levels of 5-aminolevulinate synthase mRNA were investigated in the Harderian glands of male and female Syrian hamsters by using a cDNA clone from rat liver. Female hamsters showed higher levels of mRNA than those in males, while the administration of testosterone to female hamsters led to a reduction in mRNA levels. Castration of male hamsters caused a marked elevation of mRNA levels, whereas both the exposure to constant darkness or melatonin injections to castrated males partially prevented the effects of castration. Porphyrin concentration of Harderian glands showed a strong correlation with the mRNA levels of 5-aminolevulinate synthase in all the animals studied. These results lead to the conclusion that in this system, porphyrin metabolism is controlled through hormonal regulation of 5-aminolevulinate synthase gene expression.

Sonographic diagnosis of adrenal hemorrhage in patients with fulminant meningococcal septicemia

We report two patients with fulminant meningococcal septicemia, in whom massive bilateral adrenal hemorrhages were diagnosed by ultrasound. Low plasma cortisol levels were found in one patient who eventually died. The other patient survived and has remained asymptomatic for the last three years. His adrenal function is normal. We suggest that routine ultrasound examination should be performed in patients with meningococcal sepsis and shock in order to clarify the prevalence of a renal hemorrhage. Determination of plasma cortisol levels in patients with adrenal hemorrhage, would allow identification of those with adrenal insufficiency who may benefit from steroid replacement.

Osteonectin promoter. DNA sequence analysis and S1 endonuclease site potentially associated with transcriptional control in bone cells

To understand the basis of osteonectin (SPARC) transcriptional regulation, we have isolated a bovine genomic clone (lambda Og15) encoding exon 1 and 15 kilobase pairs (kb) of flanking DNA. Direct RNA sequencing of the 5' end of the osteonectin message showed it contained a sequence identical to that of a 2.4-kb EcoRI-BamHI fragment located midway in the clone lambda Og15. The results indicate exon 1 is located 10 kb away from exon 2 in the bovine genome. The DNA sequence unit CCTG is repeated five times in exon 1 which is composed exclusively of untranslated sequence. Sequence analysis of the 5'-flanking DNA revealed the presence of many regulatory motifs including a "GC" box with four overlapping SP1 consensus sequences. Immediately downstream from the GC box is a 72-base pair purine-rich stretch composed primarily of direct repeats of the sequence motifs GGGGA and GGA (GAGA box). Digestion of the flanking DNA in vitro with S1 endonuclease showed a site for the enzyme at position -55 which is just 3' to the GAGA box. Chimeric chloramphenicol acetyltransferase constructs were prepared containing the S1-sensitive site and showed substantial transcriptional activity in UMR-106 and fetal and adult human bone cells which are known to be high producers of the protein. The results indicate a potential regulatory activity of the S1 site in osteonectin gene activation.

Treatment of small cell lung cancer with a combination of VP16-213 and cyclophosphamide with cisplatin or radiotherapy

Fifty five patients with small cell lung cancer with treated with VP16-213 combination chemotherapy regimen in two consecutive series. The first series included 24 patients; 10 with limited and 14 with extensive disease were treated with VP16-213, 120 mg/m2 p.o. daily for 5 consecutive days, Cyclophosphamide 600 mg/m2 i.v. and Cisplatin 80 mg/m2 i.v. with hydratation and manitol induced diuresis. The cycle was repeated every 3 weeks. The second series included 31 similar patients, 16 limited, and 15 extensive disease, treated with VP16-213 at the same dose and Cyclophosphamide at 1,200 mg/m2 i.v. also repeated every 3 weeks; after three cycles the patients were treated with radiotherapy to the primary tumor and regional lymph nodes with 4,000 rads in a split course of three weeks interval, followed by the same combination chemotherapy. Response rate was 75% for the first series with 6 of 24 (25%) of complete responses in four limited and two extensive disease and a median survival time of 24 weeks. In the second series of patients there were 26 of 31 (83.8%) responses with 10 of 31 (32%) complete responses in nine limited and one extensive disease and a median survival time of 33 weeks for responders. Duration of response for complete responders was 36.8 weeks for the first series and 51 weeks for the second. Toxicity was mild and includes nausea and vomiting, myelosupression, alopecia in both series, with one toxic death in the second series. Both regimens are active with a low complete response rate, which was increased in the second series by the addition of radiotherapy, which did not increase overall survival.

Preoperative estimation of risk in cardiac surgery

In order to determine the usefulness of the preoperative subjective estimation of risk and compare it with preoperative estimation of risk based upon objective data, two groups of patients subjected to open heart surgery at the Catholic University of Chile Hospital were studied prospectively. Group I comprised 227 consecutive patients operated on in 1975 and group II comprised 181 consecutive patients operated on in 1979. There were several important differences in management and techniques between the two groups, which resulted in different factors perioperative mortality. Mortality in group I was related to extreme age subsets (p less than 0.01) and to duration an anoxic arrest (p less than 0.001); mortality in group II correlated only to preoperative functional class (NYHA) (p less than 0.02). Despite these differences, subjective risk estimation as preoperatively recorded by the anesthesiologist was accurate in both groups (r = 0.969, p less than 0.05 in group I and r = 0.998, p less than 0.01 in group II). It was concluded that in the absence of a universally valid objective risk index, subjective risk estimation provides a clinical index as useful as reliance upon presently available objective data.