A deep neural network: mechanistic hybrid model to predict pharmacokinetics in rat.

An important aspect in the development of small molecules as drugs or agrochemicals is their systemic availability after intravenous and oral administration. The prediction of the systemic availability from the chemical structure of a potential candidate is highly desirable, as it allows to focus the drug or agrochemical development on compounds with a favorable kinetic profile. However, such predictions are challenging as the availability is the result of the complex interplay between molecular properties, biology and physiology and training data is rare. In this work we improve the hybrid model developed earlier (Schneckener in J Chem Inf Model 59:4893-4905, 2019). We reduce the median fold change error for the total oral exposure from 2.85 to 2.35 and for intravenous administration from 1.95 to 1.62. This is achieved by training on a larger data set, improving the neural network architecture as well as the parametrization of mechanistic model. Further, we extend our approach to predict additional endpoints and to handle different covariates, like sex and dosage form. In contrast to a pure machine learning model, our model is able to predict new end points on which it has not been trained. We demonstrate this feature by predicting the exposure over the first 24 h, while the model has only been trained on the total exposure.

Wetting Characteristics of Laser-Ablated Hierarchical Textures Replicated by Micro Injection Molding.

Texturing can be used to functionalize the surface of plastic parts and, in particular, to modify the interaction with fluids. Wetting functionalization can be used for microfluidics, medical devices, scaffolds, and more. In this research, hierarchical textures were generated on steel mold inserts using femtosecond laser ablation to transfer on plastic parts surface via injection molding. Different textures were designed to study the effects of various hierarchical geometries on the wetting behavior. The textures are designed to create wetting functionalization while avoiding high aspect ratio features, which are complex to replicate and difficult to manufacture at scale. Nano-scale ripples were generated over the micro-scale texture by creating laser-induced periodic surface structures. The textured molds were then replicated by micro-injection molding using polypropylene and poly(methyl methacrylate). The static wetting behavior was investigated on steel inserts and molded parts and compared to the theoretical values obtained from the Cassie-Baxter and Wenzel models. The experimental results showed correlations between texture design, injection molding replication, and wetting properties. The wetting behavior on the polypropylene parts followed the Cassie-Baxter model, while for PMMA, a composite wetting state of Cassie-Baxter and Wenzel was observed.

Care When It Counts: Establishing Trauma-Sensitive Care as a Preventative Approach for 0-3-Year-Old Children Suffering from Trauma and Chronic Stress.

Adverse childhood experiences are an important societal concern. Children aged 0-3 are particularly vulnerable to unpredictable chronic stress due to the critical period for brain development and attachment. Trauma-sensitive care is a preventative approach to reduce the burden of stressful experiences by committing to positive relationships. Professional caregivers are ideally placed to offer trauma-sensitive care; however, earlier research reveals that the tools they need to consciously apply trauma-sensitive care principles are missing. The current study organized living labs (co-creative research method) to present trauma-sensitive care as a preventative approach aimed at children aged 0-3. Two living labs were organized in Belgium and Hungary, where professional caregivers collaborated to create a protocol that offers guidelines on how to implement trauma-sensitive care. The resulting protocol included a theoretical foundation on trauma as well as a translation of these guidelines into practical recommendations. The protocol was evaluated by incorporating it into a training intervention delivered to 100 professional caregivers from childcare organizations across four European countries. The protocol received positive feedback from participants, with results indicating a self-reported increase in knowledge, attitude and practice of trauma-sensitive care principles. We conclude that this trauma-sensitive care protocol is a promising answer to the needs of professional caregivers working with children aged 0-3.

Hepatic arterial infusion of irinotecan and EmboCept® S results in high tumor concentration of SN-38 in a rat model of colorectal liver metastases.

Intraarterial chemotherapy for colorectal liver metastases (CRLM) can be applied alone or together with embolization particles. It remains unclear whether different types of embolization particles lead to higher intratumoral drug concentration. Herein, we quantified the concentrations of CPT-11 and its active metabolite SN-38 in plasma, liver and tumor tissue after hepatic arterial infusion (HAI) of irinotecan, with or without further application of embolization particles, in a rat model of CRLM. Animals underwent either systemic application of irinotecan, or HAI with or without the embolization particles Embocept® S and Tandem™. Four hours after treatment concentrations of CPT-11 and SN-38 were analyzed in plasma, tumor and liver samples by high-performance liquid chromatography. Additionally, DNA-damage and apoptosis were analyzed immunohistochemically. Tumor tissue concentrations of SN-38 were significantly increased after HAI with irinotecan and EmboCept® S compared to the other groups. The number of apoptotic cells was significantly higher after both HAI with irinotecan and EmboCept® S or Tandem™ loaded with irinotecan compared to the control group. HAI with irinotecan and EmboCept® S resulted in an increased SN-38 tumor concentration. Both HAI with irinotecan and EmboCept® S or Tandem™ loaded with irinotecan were highly effective with regard to apoptosis.

Monitoring of erlotinib in pancreatic cancer patients during long-time administration and comparison to a physiologically based pharmacokinetic model.

PURPOSE: In this study, a therapeutic drug monitoring (TDM) of erlotinib in pancreatic cancer patients was performed over 50 weeks to reveal possible alterations in erlotinib plasma concentrations. Additionally, a physiologically based pharmacokinetic (PBPK) model was created to assess such variations in silico. METHODS: Patients with advanced pancreatic cancer received a chemotherapeutic combination of 100 mg erlotinib q.d., 500-900 mg capecitabine b.d. and 5 mg/kg bevacizumab q.2wks. Samples were analyzed by HPLC and the results were compared to a PBPK model, built with the software GastroPlus™ and based on calculated and literature data. RESULTS: The erlotinib plasma concentrations did not show any accumulation, but displayed a high inter-patient variability over the whole investigated period. Trough plasma concentrations ranged from 0.04 to 1.22 µg/ml after day 1 and from 0.01 to 2.4 µg/ml in the long-term assessment. 7% of the patients showed concentrations below the necessary activity threshold of 0.5 µg/ml during the first week. The impact of some co-variates on the pharmacokinetic parameters Cmax and AUC0-24 were shown in a PBPK model, including food effects, changes in body weight, protein binding or liver function and the concomitant intake of gastric acid reducing agents (ARAs). CONCLUSION: This study presents the approach of combining TDM and PBPK modeling for erlotinib, a drug with a high interaction potential. TDM is an important method to monitor drugs with increased inter-patient variability, additionally, the PBPK model contributed valuable insights to the interaction mechanisms involved, resulting in an effective combination from a PK perspective to ensure a safe treatment.

Inotropic effect of NCX inhibition depends on the relative activity of the reverse NCX assessed by a novel inhibitor ORM-10962 on canine ventricular myocytes.

Na+/Ca2+ exchanger (NCX) is the main Ca2+ transporter in cardiac myocytes. Its inhibition could be expected to exert positive inotropic action by accumulation of cytosolic Ca2+ ([Ca2+]i). However, we have observed only a marginal positive inotropic effect upon selective inhibition of NCX, which was enhanced when forward activity was facilitated. Here we attempted to clarify the underlying mechanism of the limited inotropic action of selective NCX inhibition by a novel inhibitor ORM-10962 on canine ventricular myocytes. 1µM ORM-10962 reduced the Ca2+ content of sarcoplasmic reticulum (SR) when the reverse NCX was favoured, while SR Ca2+ content was increased by ORM-10962 under conditions favouring the forward activity, like elevation of [Ca2+]i. L-type Ca2+ current (ICa) was not affected by 1µM ORM-10962 in the absence of SR Ca2+ release, while ICa was suppressed by ORM-10962 during normal Ca2+ cycling. The apparent degree of forward NCX inhibition was dependent on the elevation of [Ca2+]i, suggesting that an increased driving force of forward NCX can also limit the accumulation of [Ca2+i]. We concluded that in healthy myocardium the possible positive inotropic potential of NCX inhibition is considerably weaker than it was expected earlier by theoretical assumptions. The underlying mechanism may involve the autoregulation of Ca2+ handling and/or the preserved inducibility of forward NCX by high [Ca2+]i. This limitation of selective NCX inhibition seen in undiseased myocardium requires further studies in failing heart, which may allow correct evaluation of the potential therapeutic value of selective NCX inhibitors in the treatment of heart failure.

Comparison of pulmonary vascular permeability index PVPI and global ejection fraction GEF derived from jugular and femoral indicator injection using the PiCCO-2 device: A prospective observational study.

BACKGROUND: Transpulmonary thermodilution (TPTD) is used to derive cardiac output CO, global end-diastolic volume GEDV and extravascular lung water EVLW. To facilitate interpretation of these data, several ratios have been developed, including pulmonary vascular permeability index (defined as EVLW/(0.25*GEDV)) and global ejection fraction ((4*stroke volume)/GEDV). PVPI and GEF have been associated to the aetiology of pulmonary oedema and systolic cardiac function, respectively. Several studies demonstrated that the use of femoral venous access results in a marked overestimation of GEDV. This also falsely reduces PVPI and GEF. One of these studies suggested a correction formula for femoral venous access that markedly reduced the bias for GEDV. Consequently, the last PiCCO-algorithm requires information about the CVC, and correction for femoral access has been shown. However, two recent studies demonstrated inconsistencies of the last PiCCO algorithm using incorrected GEDV for PVPI, but corrected GEDV for GEF. Nevertheless, these studies were based on mathematical analyses of data displayed in a total of 15 patients equipped with only a femoral, but not with a jugular CVC. Therefore, this study compared PVPI_fem and GEF_fem derived from femoral TPTD to values derived from jugular indicator injection in 25 patients with both jugular and femoral CVCs. METHODS: 54 datasets in 25 patients were recorded. Each dataset consisted of three triplicate TPTDs using the jugular venous access as the gold standard and the femoral access with (PVPI_fem_cor) and without (PVPI_fem_uncor) information about the femoral indicator injection to evaluate, if correction for femoral GEDV pertains to PVPI_fem and GEF_fem. RESULTS: PVPI_fem_uncor was significantly lower than PVPI_jug (1.48±0.47 vs. 1.84±0.53; p<0.001). Similarly, PVPI_fem_cor was significantly lower than PVPI_jug (1.49±0.46 vs. 1.84±0.53; p<0.001). This is explained by the finding that PVPI_fem_uncor was not different to PVPI_fem_cor (1.48±0.47 vs. 1.49±0.46; n.s.). This clearly suggests that correction for femoral CVC does not pertain to PVPI. GEF_fem_uncor was significantly lower than GEF_jug (20.6±5.1% vs. 25.0±6.1%; p<0.001). By contrast, GEF_fem_cor was not different to GEF_jug (25.6±5.8% vs. 25.0±6.1%; n.s.). Furthermore, GEF_fem_cor was significantly higher than GEF_fem_uncor (25.6±5.8% vs. 20.6±5.1%; p<0.001). This finding emphasizes that an appropriate correction for femoral CVC is applied to GEF_fem_cor. The extent of the correction (25.5/20.6; 124%) for GEF and the relation of PVPI_jug/PVPI_fem_uncor (1.84/1.48; 124%) are in the same range as the ratio of GEDVI_fem_uncor/GEDVI_fem_cor (1056ml/m2/821mL/m2; 129%). This further emphasizes that GEF, but not PVPI is corrected in case of femoral indicator injection. CONCLUSIONS: Femoral indicator injection for TPTD results in significantly lower values for PVPI and GEF. While the last PiCCO algorithm appropriately corrects GEF, the correction is not applied to PVPI. Therefore, GEF-values can be used in case of femoral CVC, but PVPI-values are substantially underestimated.

Complex partial cluster seizures in cats with orofacial involvement.

Seventeen cats were presented with acute onset of complex partial seizures with orofacial involvement (salivation, facial twitching, lip smacking, chewing, licking or swallowing), motor arrest (motionless starring) and behavioural changes. In 11 cats hippocampal necrosis (HN) was confirmed by histopathology. In a further six cats hippocampal changes were suggested by magnetic resonance imaging. The mean monitoring time of eight cats which were not euthanased in the acute phase of the disease, was 408 days (60-908): four cats are still alive. In all surviving cases, the owners reported a good quality of life. We conclude that an acute cluster of complex partial seizures with orofacial involvement are often associated with HN and that HN is not necessarily a fatal condition. Supportive and antiepileptic therapy can result in remission. The long-term outcome can be good to excellent; therefore, euthanasia should be avoided in the acute phase of the signs.

Diagnostic markers for encephalitozoonosis in pet rabbits.

Encephalitozoonosis is a common disease in pet rabbits, routinely diagnosed in vivo by serological examination or post mortem by histopathology. Recently molecular techniques have become increasingly important as diagnostic tools. The application of different diagnostic markers for in vivo and post mortem determination of E. cuniculi in naturally infected pet rabbits were compared. The examined population was divided into 33 rabbits with symptoms of encephalitozoonosis (group I) and 38 animals without symptoms (group II) which were all tested by serological analysis (Indirect Immunofluorescence Test), histological examination including special spore staining (Ziehl-Neelsen, acid-fast trichrome) and conventional and nested PCR (organs, body fluids). Additionally, in group III lens material (n=10) of animals (n=9) with phacoclastic uveitis were examined by conventional PCR. Infections with E. cuniculi could be determined post mortem in 78.8% of the rabbits of group I and in 57.9% of group II by histological examination combined with spore staining. In group I 69.7% and in group II 50.0% showed seroconversion. Conventional PCR was only sufficiently sensitive in samples of eyes with phacoclastic uveitis (n=10; 100%). Therefore nested PCR was performed in tissue samples, urine and cerebrospinal fluid (CSF) with positive results in 63.6% of group I and 42.1% of group II. Positive results in serology, pathohistology (spore detection and histological changes in the brain and/or kidneys) and nested PCR were obtained in 52.1% of the rabbits (group I and II, n=71), whereas 31.0% showed negative results in all three diagnostic techniques. 5.6% of the rabbits were positive in two methods and 11.3% in one method. In 37 rabbits (group I and II) with positive results in nested PCR, E. cuniculi DNA could be detected more frequently in the brain (91.9%) than in the kidney (54.1%). Furthermore nested PCR of urine revealed positive results in 29.7% of the rabbits (n=37) with seroconversion and/or confirmed E. cuniculi infection by spore detection. All 25 samples of CSF tested negative in nested PCR. Conventional PCR of eyes with phacoclastic uveitis was an excellent diagnostic marker in living rabbits, while nested PCR of urine or CSF was not reliable. Histological examination combined with special staining was the most sensitive method in post mortem diagnostics. Nested PCR appears to be a good post mortem method to investigate organs, especially brains, of chronically infected animals.

Encephalitozoonosis in pet rabbits (Oryctolagus cuniculus): pathohistological findings in animals with latent infection versus clinical manifestation.

Encephalitozoon cuniculi is a common infectious agent of rabbits. The aim of this study was to determine the distribution and extent of histological lesions in the brain and in the kidney of naturally infected pet rabbits with or without clinical encephalitozoonosis. In 71 animals (33 with symptoms) which died or were euthanised, histopathological examination including staining of spores (Ziehl-Neelsen, acid-fast trichrome) was performed and changes were described quantitatively. The cerebrum was the most frequently affected brain region (97.5%), whilst the cerebellum (55%) and the vestibular cores (37.5%) were less commonly concerned. Granulomas were found in 77.5% of animals with encephalitis and in 12.5% of rabbits with interstitial nephritis. Although cerebral granulomas were found irrespective of the grade of histological changes, they were significantly correlated with changes at higher grades. There was no correlation between the severity of encephalitis and neurological symptoms. Since severe lesions were also found in clinically inconspicuous animals, histological findings of inflammatory lesions are not indicative of overt encephalitozoonosis as the causative agent for neurological signs. Other diseases causing neurological symptoms, such as suppurative encephalitis, otitis media as well as malignant lymphoma were also detected in the rabbit population that was examined in the present study.

Clinical symptoms and diagnosis of encephalitozoonosis in pet rabbits.

Infections with Encephalitozoon cuniculi in rabbits are observed at increasing frequency and are known as opportunistic infections in immunocompromised humans. 191 pet rabbits with suspected encephalitozoonosis, presented at the Animal Hospital of the Veterinary University of Vienna (Austria), were included in this study. Rabbits were serologically examined for antibodies against E. cuniculi (144 positive out of 184 rabbits with suspected encephalitozoonosis compared to 14 positive out of 40 clinically healthy rabbits tested as part of a standard health check) and Toxoplasma gondii (8 positive out of 157). Of the 144 seropositive rabbits with clinical signs, 75% showed neurological symptoms, 14.6% demonstrated phacoclastic uveitis and 3.5% suffered from renal failure. 6.9% of the animals had combined symptoms. Vestibular disease dominated within the rabbits that showed neurological symptoms. Polymerase chain reaction (PCR) could not detect parasite DNA in urine or cerebrospinal fluid (CSF), but did so in 4 out of 5 samples of liquefied lens material in cases with phacoclastic uveitis due to lens capsule rupture. Additionally further diagnostic procedures, such as inspection of the external ear canal (N=69), radiography of the tympanic bullae (N=65) were performed to rule out differential diagnosis. 54.2% of the patients exhibiting neurological symptoms recovered within a few days, while 87.5% of the rabbits suffering from renal failure died or had to be euthanized.

Poxvirus infection in a great tit (Parus major).

Four great tits (Parus major) with nodular lesions suggestive of poxvirus infections were observed in a garden in Vienna, Austria. One of the birds was submitted for examination. Because of its poor condition, the bird had to be euthanatized and was subsequently necropsied. An avipoxvirus infection was confirmed by histopathology, electron microscopy, and polymerase chain reaction and sequencing. This is the second report of naturally occurring poxvirus infection in great tits and the first of its kind in central Europe.

Malignant B-cell lymphoma of the Harder's gland in a rabbit.

A 22-month-old, female rabbit was presented with a 1-day history of acute unilateral exophthalmos. Ultrasonography and computed tomography (CT) of the orbit revealed an orbital mass. Retrobulbar lymphoma was diagnosed following fine-needle aspiration biopsy (FNAB). Thoracic radiographs were normal, and ultrasonography of the abdomen showed focal hypoechoic thickening of the bowel wall and hypoechoic enlarged lymph nodes. The rabbit was euthanized and histopathology identified the retrobulbar mass as B-cell malignant lymphoma of the Harder's gland. Mesenteric lymph nodes, caecum, and both kidneys were also affected. This is the first documented case of malignant lymphoma of the Harder's gland in a rabbit.