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Results for “Preclinical study”

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PubMed1977

The pharmacology and subacute toxicology of dopamine.

Preclinical studies with dopamine showed a unique spectrum of biological activities which suggested that it might be of therapeutic use in the clinical syndromes of shock and low cardiac output. Most prominent among these were its effects on cardiac output, renal perfusion, and vital organ flow. The unique effect on renal function and the subsequent studies by Goldberg and his colleagues led to the recognition of a previously unknown catecholamine receptor site, the 'dopaminergic receptor'. Studies on the toxicology of dopamine in our laboratories suggested that dopamine could be safely used in the clinic.

Animals↗

PubMed1978

Cumulative dose-response curves for early evaluation of bronchodilator drugs.

SM 220, a new beta-receptor agonist, was compared with terbutaline by construction of dose response curves for FEV1, heart rate and blood pressure. The pharmacological profile of SM 220 after preclinical studies was that of a potent and highly selective bronchodilator. In this study the beta2 selectivity of SM 220 was poorer than that of terbutaline. The importance of commencing clinical evaluation of bronchodilators with a dose-response test is stressed.

Adrenergic beta-Agonists↗

PubMed1978

[Clinical results in the treatment of chronic obstructive bronchitis with ambroxol in comparison with bromhexine (author's transl)].

Preclinical studies of trans-4-[(2-amino-3,5-dibromobenzyl)-amino]-cyclohexanol hydrochloride (ambroxol, NA 872), the metabolite VIII of bromhexine, show that it is superior to the basic substance with respect to its bronchosecretolytic properties. In a double blind study 30 patients suffering from chronic obstructive bronchitis received in randomized order 36 mg bromhexine/d or 45 mg ambroxol/d, each over a period of 4 weeks. The following parameters were studied: mean bronchial flow resistance, forced expiratory volume, static lung volumes, arterial blood gases as well as clinical and laboratory results. Bromhexine was not associated with a change in lung function parameters. Ambroxol was associated with a 25% reduction of the average bronchial flow resistance. The forced expiratory volume improved over the period on the average by 14%. Patients with slight arterial hypoxemia had an increase in the partial pressure of arterial oxygen. The patients found both substances facilitated expectoration. Further studies appear necessary to confirm the improved respiratory performance under the influence of ambroxol.

Adult↗

PubMed1978

Intracellular distribution of 57Co-bleomycin.

Since the first promising results of Nouel et al. 1972, additional positive experience has been obtained with 57Co-Bleomycin (57Co-BLM) as a tumour-localizing agent. In this preclinical study, mice with transplanted osteosarcoma and lymphosarcoma were used and rats with transplanted rhabdomyosarcoma. 57CoCl2 served as a control substance. 57Co-BLM had concentrated in the tumours with a factor 2 to 10 as compared to the (normal) liver of the animals. No preferential concentration in the tumours was found when 57CoCl2 was used. The highest specific activity of 57Co-BLM (cpm/mg protein) was found in a fraction containing mitochondria and lysosomes. Evidence for a lysosomal localization of this diagnostic compound was obtained from experiments in which the mitochondrial-lysosomal fraction was treated with hypertonic media of different osmolarities. Conditions could be found in which many lysosomes burst while almost all mitochondrial were intact. From these experiments it appeared that the radioactivity in the particles obtained from animals injected wtih 57Co-BLM was released very rapidly. It is concluded that 57Co-BLM is preferentially localized in the heavy lysosomes sedimenting together with most of the mitochondria of the cell and that these structures are more fragile than the light lysosomes.

Animals↗

PubMed1978

Isoprinosine: an overview.

Isoprinosine appears to have a relatively low degree of both acute and chronic toxicity in both rodent and nonrodent species. Preclinical studies have demonstrated that isoprinosine can inhibit the growth of both DNA and RNA viruses as well as potentiate cell-mediated immune response both in vitro and in vivo. Clinical studies with rhinovirus, herpesvirus, and influenza virus infections in man demonstrated that isoprinosine treatment reduced clinical symptoms and enhanced certain cell-mediated immune responses compared to placebo-treated controls.

Animals↗

PubMed2026

Evaluation of metabolic, reproductive, and gut microbiota alterations in a comparative study of different preclinical models of polycystic ovary syndrome.

Polycystic ovary syndrome (PCOS) is a multifaceted, complex metabolic and endocrine disease where gut flora is considered an important factor in causing PCOS. This study aimed to identify a suitable PCOS model that contributes to gut microbial dysbiosis and metabolic and hormonal disturbances. Prepubertal SD rats were administered with normal control (NC), dihydrotestosterone (DHT), DHT with fructose (F), DHT+ high fat diet (HFD) for 91 days, dehydroepiandrosterone (DHEA), DHEA with fructose, DHEA with HFD for 30 days, sodium valproate (SV), sodium valproate with fructose, and sodium valproate with HFD for 21 days. The estrous cycles were assessed over this timeframe. At the end of the experiment, superoxide dismutase and uterine and ovarian morphology were evaluated, along with hormone levels, lipid profiles, and 16S rRNA genomic sequencing. All models exhibited PCOS characteristics, including hormonal imbalances, insulin resistance (p ≤ .001), multiple follicular cysts on ultrasonography, and histological alterations. Gut microbial dysbiosis was observed across all PCOS-induced groups; however, the DHT alone group showed more pronounced alterations in microbial composition than the other experimental groups. Specifically, the DHT alone group exhibited reduced abundance of Firmicutes and increased abundance of Proteobacteria. Among the evaluated models, the DHT-only model showed more pronounced metabolic, hormonal, reproductive, and gut microbial alterations and may serve as a suitable model for PCOS research.

Animals↗

PubMed2018

Muscle miRNAome shows suppression of chronic inflammatory miRNAs with both prednisone and vamorolone.

Corticosteroids are highly prescribed and effective anti-inflammatory drugs but the burden of side effects with chronic use significantly detracts from patient quality of life, particularly in children. Developing safer steroids amenable to long-term use is an important goal for treatment of chronic inflammatory diseases such as Duchenne muscular dystrophy (DMD). We have developed vamorolone (VBP15), a first-in-class dissociative glucocorticoid receptor (GR) ligand that shows the anti-inflammatory efficacy of corticosteroids without key steroid side effects in animal models. miRNAs are increasingly recognized as key regulators of inflammatory responses. To define effects of prednisolone and vamorolone on the muscle miRNAome, we performed a preclinical discovery study in the mdx mouse model of DMD. miRNAs associated with inflammation were highly elevated in mdx muscle. Both vamorolone and prednisolone returned these toward wild-type levels (miR-142-5p, miR-142-3p, miR-146a, miR-301a, miR-324-3p, miR-455-5p, miR-455-3p, miR-497, miR-652). Effects of vamorolone were largely limited to reduction of proinflammatory miRNAs. In contrast, prednisolone activated a separate group of miRNAs associated with steroid side effects and a noncoding RNA cluster homologous to human chromosome 14q32. Effects were validated for inflammatory miRNAs in a second, independent preclinical study. For the anti-inflammatory miRNA signature, bioinformatic analyses showed all of these miRNAs are directly regulated by, or in turn activate, the inflammatory transcription factor NF-κB. Moving forward miR-146a and miR-142 are of particular interest as biomarkers or novel drug targets. These data validate NF-κB signaling as a target of dissociative GR-ligand efficacy in vivo and provide new insight into miRNA signaling in chronic inflammation.

Animals↗

PubMed2026

A novel triple-knockout allogeneic BCMA CAR T-cell therapy (CT0590) for multiple myeloma: preclinical and phase 1 study.

Host-versus-graft reaction (HVGR) is a major challenge in allogeneic chimeric antigen receptor (CAR) T-cell therapy. To counter host natural killer (NK) cell attacks, we armored allogeneic, HLA-I-deficient, B-cell maturation antigen (BCMA)-targeting CAR T cells with an NKG2A CAR. In vitro and animal studies demonstrated that allogeneic CAR-NKG2A T cells effectively resisted host NK cell-mediated killing. BCMA and NKG2A dual-targeting allogeneic CAR T cells (CT0590) resisted killing by NK cells and showed robust antitumor activity in preclinical in vivo models. On the basis of these data, a first-in-human study enrolled 5 patients (4 with relapsed and refractory multiple myeloma [RRMM] and 1 with primary plasma cell leukemia [pPCL]). CT0590 was well tolerated and caused no dose-limiting toxicities, treatment-related death, or graft-versus-host disease. Three patients achieved confirmed responses, including 2 with stringent complete response (sCR). Notably, sCR in the patient with RRMM was still ongoing (duration of response >23 months) at the time of data cutoff, and sCR in the patient with pPCL lasted for 20 months. Both patients showed robust expansion of universal CAR T cells (maximum concentration of >280 000 copies per μg genomic DNA) and higher baseline NKG2A expression on NK cells than nonresponders. These results suggest that CAR-NKG2A technology may overcome HVGR, especially in patients with elevated NKG2A expression on NK cells. Further studies of CT0590 in RRMM and pPCL are warranted. This trial was registered at www.clinicaltrials.gov as NCT05066022.

Humans↗

PubMed1979

Pharmacological studies on new oncostatic acridine derivatives. I. Acute and subchronic action.

Preclinical pharmacological studies of two acridine derivatives, dihydrochloride N10-oxide 1-nitro-9-/3-dimethylaminopropylamino/-acridine (C-666) and dihydrochloride 1-nitro-9-[(2-dimethylamino)-1-methylethylamino]-acridine (C-829) are reported. Both compounds are characterized by biological activity, poor absorption from the gastrointestinal tract and local irritant action. Quality differences in an effect of both investigated acridine derivatives on the central nervous system were noted. C-666 proved to be deprived of the effect typical of the central component compounds while C-829 demonstrated mostly sedative activity. Clear dissociation in the effect of these both compounds was seen in in vitro experiments on isolated smooth muscle organs. C-666 acted spasmolytically on the motory action of intestine muscles while C-829 acted spastically. Both preparations had clearly hipotensic influence which can be due to the vascular effect and to their affinity with the intramyocardium transmitting system. Neither a distinctive effect on reproductivity of animals nor the teratogenic action were observed in the functional experiments.

Acridines↗

PubMed2013

Selection and evaluation of clinically relevant AAV variants in a xenograft liver model.

Recombinant adeno-associated viral (rAAV) vectors have shown early promise in clinical trials. The therapeutic transgene cassette can be packaged in different AAV capsid pseudotypes, each having a unique transduction profile. At present, rAAV capsid serotype selection for a specific clinical trial is based on effectiveness in animal models. However, preclinical animal studies are not always predictive of human outcome. Here, in an attempt to further our understanding of these discrepancies, we used a chimaeric human-murine liver model to compare directly the relative efficiency of rAAV transduction in human versus mouse hepatocytes in vivo. As predicted from preclinical and clinical studies, rAAV2 vectors functionally transduced mouse and human hepatocytes at equivalent but relatively low levels. However, rAAV8 vectors, which are very effective in many animal models, transduced human hepatocytes rather poorly-approximately 20 times less efficiently than mouse hepatocytes. In light of the limitations of the rAAV vectors currently used in clinical studies, we used the same murine chimaeric liver model to perform serial selection using a human-specific replication-competent viral library composed of DNA-shuffled AAV capsids. One chimaeric capsid composed of five different parental AAV capsids was found to transduce human primary hepatocytes at high efficiency in vitro and in vivo, and provided species-selected transduction in primary liver, cultured cells and a hepatocellular carcinoma xenograft model. This vector is an ideal clinical candidate and a reagent for gene modification of human xenotransplants in mouse models of human diseases. More importantly, our results suggest that humanized murine models may represent a more precise approach for both selecting and evaluating clinically relevant rAAV serotypes for gene therapeutic applications.

Animals↗

PubMed2026

Deep learning-assisted, pathogenesis-informed lung histopathology scoring in preclinical mouse models of SARS-CoV-2 and influenza A infection.

INTRODUCTION: SARS-CoV-2 and influenza A virus (IAV) cause viral pneumonia, yet their lung lesions evolve with distinct spatial organization and resolution-phase architecture. In preclinical murine studies, H&E histopathology is a primary endpoint, but burden-focused semiquantitative scoring can miss pathogen- and phase-specific differences in lesion topology, compartmental involvement, inflammatory organization, and repair. We aimed to define virus- and phase-specific morphologic signatures and translate them into a practical, pathogenesis-informed scoring guide, supported by whole-slide convolutional neural network (CNN) analysis with class activation mapping (CAM). METHODS: Mice were infected under standardized conditions and evaluated during the early, peak-injury, and late phases of infection, corresponding to 2~3, 5~8, and 14 days post-infection (dpi), respectively. Lungs were assessed by H&E with semiquantitative scoring and by immunostaining to map viral antigen distribution and epithelial tropism. Whole-slide CNN models were trained for virus- and phase-specific classification, and CAM localized discriminative regions. RESULTS: Dose titration established reproducible lethal and sublethal infection conditions for both viruses. Viral antigen kinetics diverged, with SARS-CoV-2 peaking early and declining toward clearance by the resolution phase, whereas IAV peaked later and declined by the resolution phase, paralleling distinct injury-repair trajectories. CNN/CAM analysis distinguished virus- and phase-specific histologic patterns across the early, peak-injury, and resolution phases of infection and highlighted spatial signatures consistent with expert review. At the peak-injury phase, SARS-CoV-2 lungs showed broad alveolar/interstitial involvement, whereas IAV exhibited bronchocentric inflammatory organization. During the resolution phase, IAV showed prominent epithelial regeneration with remodeling-forward architecture, while SARS-CoV-2 more often retained localized residual inflammatory foci. Across both infections, tissue inflammatory composition shifted over time, with higher neutrophil representation during the peak-injury phase and a relative increase in lymphocytic representation during the resolution phase. Integrating lesion topology/distribution, edema, epithelial injury-regeneration, remodeling features, and lymphocyte predominance, we proposed a pathogen-resolved, phase-informed histopathology scoring guide with recommended evaluation windows for each model. CONCLUSION: Together, these findings define virus- and phase-specific morphologic programs that inform respiratory virus pathogenesis in mice and can be translated into practical scoring criteria for preclinical respiratory virus studies.

Animals↗

PubMed1978

Cardiac lesions induced by chemicals.

Chemically induced cardiomyopathies are frequently the consequences of a cardiac metabolic imbalance brought about by exaggerated functional affects. The infarctlike lesions induced by adrenergic beta-receptor stimulants and the vasodilating antihypertensives serve as examples of this phenomenon. Direct cardiotoxic mechanisms not related to cardiovascular functional effects are responsible for another class of toxic cardiomyopathy. An example of this is the cardiomyopathy produced by the anthracycline antineoplastic agents. The pathogenesis, morphological changes and toxicologic features of these cardiomyopathies are described with particular reference to their detection in preclinical toxicity studies.

Acute Disease↗

PubMed1979

Toxicology of clobazam.

1 Extensive toxicological investigations of clobazam are summarized. 2 LD50 values after oral administration ranged from 100 mg/kg in the dog to 6000 mg/kg in the rat. 3 Long-term repeated dose studies have shown withdrawal effects in the dog and monkey (notably convulsions leading to death), similar to those known to occur with other benzodiazepines. 4 It is concluded that the overall safety and tolerability of clobazam have been demonstrated in the preclinical animal studies.

Animals↗

PubMed2026

Topical Donepezil for Cholinergic Modulation in Chronic Wound Repair.

Chronic wounds result from combined defects in vascular perfusion, inflammatory resolution, and epithelial repair. The skin's non-neuronal cholinergic system (NNCS), formed by keratinocytes, endothelial cells, fibroblasts, and immune cells that synthesise and respond to acetylcholine (ACh), helps coordinate these processes through muscarinic and nicotinic receptors. Inhibition of acetylcholinesterase (AChE) increases local ACh concentrations and may engage two key pathways supported by preclinical data: M3 muscarinic receptor (M3 mAChR)-endothelial nitric oxide synthase (eNOS)-nitric oxide (NO)-mediated vasodilation, and α7 nicotinic acetylcholine receptor (α7-nAChR)-mediated suppression of pro-inflammatory cytokines. Donepezil is a reversible, selective AChE inhibitor with physicochemical properties compatible with dermal administration. Low-dose or microneedle dermal delivery has produced dermal exposure with limited systemic uptake in animal and ex vivo skin studies. In preclinical diabetic wound models, nicotinic receptor activation accelerated healing, reduced inflammatory signalling, and improved control of bacterial burden. We hypothesise that topical donepezil formulated for localised dermal delivery could restore cholinergic signalling within the wound microenvironment by increasing local ACh concentrations. This approach may complement metabolic therapies that support arginine-NO coupling and redox balance. Controlled pilot studies should assess local cutaneous pharmacodynamics, perfusion responses, and wound-closure outcomes.

Donepezil↗

PubMed2026

Optimized AAV5-RPGR ORF15 Gene Therapy Rescues Photoreceptor Structure and Function in X-Linked Retinitis Pigmentosa Mouse Model.

PURPOSE: To develop and evaluate an rAAV5-based gene therapy vector expressing an optimized human RPGR ORF15 transgene (rAAV5-RPGR) for the treatment of X-linked retinitis pigmentosa caused by RPGR mutations, addressing the challenges of cloning the unstable wild-type ORF15 sequence. DESIGN: This was a prospective experimental study. SUBJECTS: This was an animal study. METHODS: An optimized RPGR ORF15 sequence was designed to eliminate problematic secondary structures and cryptic splice sites. In vitro expression was validated in HEK 293T and photoreceptor-like 661 W cells. A complete Rpgr knockout mouse model (Rpgr-knockout [KO]) was generated and characterized phenotypically. Therapeutic efficacy was assessed in Rpgr-KO mice via subretinal injection of rAAV5-RPGR at low (1 × 10⁹ vg/eye), medium (3 × 10⁹ vg/eye), or high (1 × 10¹⁰ vg/eye) doses. Structural and functional outcomes were evaluated at 12- and 14-month postinjection. Short-term safety was assessed in rabbits 1 month after subretinal injection. MAIN OUTCOME MEASURES: Level of RPGR protein expression and Protein isoform profile (elimination of truncated isoforms), Cellular localization of transgene expression and Dose-dependence of expression, outer nuclear layer thickness, and electroretinography parameters. RESULTS: (1) The optimized vector increased RPGR protein expression 3.3-fold in vitro compared to wild-type and eliminated truncated isoforms. (2) Subretinal delivery of rAAV5-RPGR in mice demonstrated dose-dependent transgene expression localized correctly to photoreceptor inner segments. (3) In Rpgr-KO mice, high-dose treatment significantly preserved outer nuclear layer thickness at the injection site (42% greater than controls at 14 months, P < .01) and central retina (P < .05), reduced aberrant rhodopsin mislocalization (P < .01), and partially restored retinal function. ERG showed significantly improved scotopic a-wave (≥100 vs <90 µV in controls at 10 cd·s/m²) and photopic b-wave amplitudes (49-66 vs 31-46 µV at 30 cd·s/m²) in treated mice. (4) No vector-related toxicity was observed in rabbits. CONCLUSIONS: rAAV5-RPGR mediated efficiently, targeted expression of optimized RPGR-ORF15, significantly preserved photoreceptor structure and function in a severe X-linked retinitis pigmentosa mouse model, and demonstrated a favorable safety profile. This study provides preclinical proof-of-concept for RPGR-targeted gene replacement therapy.

Animals↗

PubMed1978

Antimalarial activities of WR-194,965, an alpha-amino-o-cresol derivative.

Pilot appraisals of the activities of WR-194,965 and WR-204,165, two closely related o-cresol derivatives (both Mannich bases), in owl monkeys infected with the multidrug-resistant Vietnam Smith strain of Plasmodium falciparum showed that these compounds had similar levels of efficacy. Total course doses effecting 90% cures (CD(90)s) were 27 and 37 mg/kg of body weight for the respective compounds, values almost identical to the CD(90) of mefloquine (a highly promising 4-quinolinemethanol) against infections with the same strain, and the CD(90)s of chloroquine against infections with 4-aminoquinoline-susceptible strains. Expanded studies of the activities of WR-194,965 against infections with the Smith strain of P. falciparum and Vietnam Palo Alto strain of P. vivax, designed to guide projected evaluations in human volunteers, showed: (i) that the activity of this compound was a function of total dose administered, with single doses as effective as the same amount delivered in three or seven successive daily fractions; (ii) that all regimens effected rapid clearance of parasitemia; and (iii) that based on CD(90)s, this agent was twice as active against infections with the Palo Alto strain of P. vivax as against the Smith strain of P. falciparum. These findings, together with results of preclinical pharmacological studies pursued elsewhere, provided support for studies in human volunteers now underway.

Animals↗

PubMed1979

[Study with serial sectioning of 312 preclinical cancers of the uterine cervix. Indications for selective treatment (author's transl)].

The authors have studied by step serial sectioning 312 cervix the most obtained by cold knife conization. They have studied too, the frequency of inadequate resection (i.e. non in sano conization) and clinically occult invasion according to the age of patients. Conization is adequate for the treatment of 70 per cent of women less than 30 years of age. But after 50 it is sufficient in only 22 per cent of the patients. Conization must be performed in most cases of grade III to V cervical smear (according to Papanicolaou's classification). The cervical cone must be studied by serial sectioning (every 500 microns). According to the result of this study the treatment must be selected : conization for in situ carcinoma resected in sano, simple hysterectomy for in situ carcinoma not resected in situ and Wertheim type operation for invasive carcinoma.

Adult↗

PubMed2026

Harnessing Id1 as a biomarker in a plasmid reporter system for cervical cancer.

Stagnancy of ten-year cervical cancer (CC) incidence in the U.S., despite screening advancements, suggests the need for new CC screening technologies. This study in preclinical CC models evaluated a diagnostic plasmid that induces expression of a reporter (secreted embryonic alkaline phosphatase, SEAP) through the control of cancer-specific promoter sequence (inhibitor of differentiation 1, Id1). The plasmid (pId1-SEAP) was used to transfect CC cells in vitro and characterize SEAP production based on Id1 expression. Western Blot and immunohistochemistry were used to establish Id1 expression in cell models and human tissues. Timed transfections in various conditions were used to correlate Id1 and SEAP expression. CC cell lines expressed increased normalized baseline Id1 (HeLa 3.0 ± 0.13, SiHa 2.9 ± 0.27, both P < 0.0001) compared to non-cancer 3T3 fibroblasts (1.0 ± 0.0). Normal cervical tissues had a mean Id1 staining value of 3E4 ± 3E4, while early- and late-stage CC tissues had increased mean Id1 staining (3E5 ± 1E5 P < 0.0001 and 2E5 ± 1E5 P = 0.0002, respectively). HeLa and SiHa lines produced increased normalized SEAP (0.63 ± 0.25 and 0.50 ± 0.10, P < 0.05) compared to 3T3 cells, both with pId1-SEAP (0.16 ± 0.058). As few as 12,500 pId1-SEAP transfected HeLa cells resulted in increased SEAP (3E4 ± 3E3 P = 0.004) compared to background (1E4 ± 4E2). SiHa xenograft ex vivo tumor transfected with 25 µg/µL pId1-SEAP produced significantly greater SEAP (21.7 ± 8.6, P = 0.0003) relative to muscle transfected in the same conditions (0.94 ± 0.24). pId1-SEAP can transfect CC cells to produce SEAP proportionally to endogenous Id1 expression, demonstrating its potential for additional studies in CC models.

Female↗