scholarly journals Chronic Subclinical Prion Disease Induced by Low-Dose Inoculum

2002 ◽  
Vol 76 (5) ◽  
pp. 2510-2517 ◽  
Author(s):  
Alana M. Thackray ◽  
Michael A. Klein ◽  
Adriano Aguzzi ◽  
Raymond Bujdoso
Keyword(s):  
Brain Tissue ◽  
Prion Disease ◽  
Low Dose ◽  
Clinical Signs ◽  
Rocky Mountain ◽  
Rapid Onset ◽  
Distinct Pattern ◽  
High Dose ◽  
Terminal Disease ◽  
Subclinical Disease

ABSTRACT We have compared the transmission characteristics of the two mouse-adapted scrapie isolates, ME7 and Rocky Mountain Laboratory (RML), in tga20 mice. These mice express elevated levels of PrP protein compared to wild-type mice and display a relatively short disease incubation period following intracerebral prion inoculation. Terminal prion disease in tga20 mice induced by ME7 or RML was characterized by a distinct pattern of clinical signs and different incubation times. High-dose RML inoculated intracerebrally into tga20 mice induced the most rapid onset of clinical signs, with mice succumbing to terminal disease after only 58 ± 3 days. In contrast, high-dose ME7 gave a mean time to terminal disease of 74 ± 0 days. Histological examination of brain sections from prion-inoculated tga20 mice at terminal disease showed that ME7 gave rise to a more general and extensive pattern of vacuolation than RML. Low-dose inoculum failed to induce terminal disease but did cause preclinical symptoms, including the appearance of reversible clinical signs. Some mice oscillated between showing no clinical signs and early clinical signs for many months but never progressed to terminal disease. Brain tissue from these mice with chronic subclinical prion disease, sacrificed at >200 days postinoculation, contained high levels of infectivity and showed the presence of PrPSc. Parallel analysis of brain tissue from mice with terminal disease showed similar levels of infectivity and detectable PrPSc. These results show that high levels of infectivity and the presence of the abnormal isomer of PrP can be detected in mice with subclinical disease following low-dose prion inoculation.

Intensive Initial Oral Anticoagulation and Shorter Heparin Treatment in Deep Vein Thrombosis

1984 ◽  
Vol 52 (03) ◽  
pp. 276-280 ◽  
Author(s):  
Sam Schulman ◽  
Dieter Lockner ◽  
Kurt Bergström ◽  
Margareta Blombäck
Keyword(s):  
Deep Vein Thrombosis ◽  
Oral Anticoagulation ◽  
Dose Group ◽  
Low Dose ◽  
Clinical Signs ◽  
Coagulation Factor ◽  
High Dose ◽  
Vein Thrombosis ◽  
Heparin Treatment ◽  
Deep Vein

SummaryIn order to investigate whether a more intensive initial oral anticoagulation still would be safe and effective, we performed a prospective randomized study in patients with deep vein thrombosis. They received either the conventional regimen of oral anticoagulation (“low-dose”) and heparin or a more intense oral anticoagulation (“high-dose”) with a shorter period of heparin treatment.In the first part of the study 129 patients were randomized. The “low-dose” group reached a stable therapeutic prothrombin complex (PT)-level after 4.3 and the “high-dose” group after 3.3 days. Heparin was discontinued after 6.0 and 5.0 days respectively. There was no difference in significant hemorrhage between the groups, and no clinical signs of progression of the thrombosis.In the second part of the study another 40 patients were randomized, followed with coagulation factor II, VII, IX and X and with repeated venograms. A stable therapeutic PT-level was achieved after 4.4 (“low-dose”) and 3.7 (“high-dose”) days, and heparin was discontinued after 5.4 and 4.4 days respectively. There were no clinical hemorrhages, the activity of the coagulation factors had dropped to the same level in both groups at the time when heparin was discontinued and no thromboembolic complications occurred.Our oral anticoagulation regimen with heparin treatment for an average of 4.4-5 days seems safe and reduces in-patient costs.

Extended-release Buprenorphine, an FDAindexed Analgesic, Attenuates Mechanical Hypersensitivity in Rats (Rattus norvegicus)

2021 ◽  
Author(s):  
Eden D Alamaw ◽  
Benjamin D Franco ◽  
Katechan Jampachaisri ◽  
Monika K Huss ◽  
Cholawat Pacharinsak
Keyword(s):  
Extended Release ◽  
Low Dose ◽  
Clinical Signs ◽  
High Dose ◽  
Male Adult ◽  
Pain Model ◽  
Mechanical Hypersensitivity ◽  
Treatment Groups ◽  
Incisional Pain ◽  
Thermal Hypersensitivity

A new extended-release buprenorphine (XR), an FDA-indexed analgesic, has recently become available to the laboratoryanimal community. However, the effectiveness and dosing of XR has not been extensively evaluated for rats. We investigatedXR’s effectiveness in attenuating postoperative hypersensitivity in a rat incisional pain model. We hypothesized that highdose of XR would attenuate mechanical and thermal hypersensitivity more effectively than the low dose of XR in this model. We performed 2 experiments. In experiment 1, male adult Sprague–Dawley rats (n = 31) were randomly assigned to 1 of the 4 treatment groups: 1) saline (saline, 0.9% NaCl, 5 mL/kg, SC, once); 2) sustained-release buprenorphine (Bup-SR; 1.2 mg/kg, SC, once), 3) low-dose extended-release buprenorphine (XR-Lo; 0.65 mg/kg, SC, once), and 4) high-dose extended-releasebuprenorphine (XR-Hi; 1.3 mg/kg, SC, once). After drug administration, a 1 cm skin incision was made on the plantar hind paw under anesthesia. Mechanical and thermal hypersensitivity were evaluated 1 d before surgery (D-1), 4 h after surgery (D0), and for 3 d after surgery (D1, D2, and D3). In experiment 2, plasma buprenorphine concentration (n = 39) was measured at D0, D1, D2, and D3. Clinical observations were recorded daily, and a gross necropsy was performed on D3. Mechanical and thermal hypersensitivity were measured for 3 d (D0-D3) in the saline group. Bup-SR, XR-Lo, and XR-Hi effectively attenuated mechanical hypersensitivity for D0-D3. Plasma buprenorphine concentrations remained above 1 ng/mL on D0 and D1 in all treatment groups. No abnormal clinical signs were noted, but injection site reactions were evident in the Bup-SR (71%), XR-Lo (75%), and XR-Hi (87%) groups. This study indicates that XR-Hi did not attenuate hypersensitivity more effectivelythan did XR-Lo in this model. XR 0.65 mg/kg is recommended to attenuate postoperative mechanical hypersensitivity for upto 72 h in rats in an incisional pain model.

P061 Kawasaki disease: a case series from a tertiary Hospital in Kenya

Rheumatology ◽  
2021 ◽  
Vol 60 (Supplement_5) ◽  
Author(s):  
C Njeru ◽  
A Migowa
Keyword(s):  
Kawasaki Disease ◽  
Incidence Rate ◽  
Low Dose ◽  
Clinical Signs ◽  
Case Series ◽  
Cervical Lymphadenopathy ◽  
Patient Characteristics ◽  
Tertiary Hospital ◽  
High Dose ◽  
True Incidence

Abstract Background Kawasaki disease (kDa) is a childhood vasculitides that affects small and medium-sized arteries. It is self-limiting but when left untreated can cause coronary artery aneurysms in about 25% of children1. The diagnosis is clinical and is made with the criteria of fever for at least five days, and at least four out of five other clinical signs: bilateral non-exudative conjunctivitis, oral mucous membrane changes, peripheral extremity changes, polymorphous rash, and cervical lymphadenopathy. Incomplete kDa is diagnosed with fever for at least five days and at least 2–3 of the principal signs, with suggestive lab investigations and lack of an alternative diagnosis1. kDa is named after Dr Tomisaku Kawasaki who first described it in 1967 in Japan2. The highest incidence of kDa continues to be reported among Asian children, with an incidence rate of 264.8 per 100 000 population aged 0–4 years as per Japan’s latest nationwide survey3. In Africa, the true incidence is unknown but several case reports have been published. A 2016 paper by Gorrab et al.4 found that the annualized incidence rate of kDa in the Maghreb children living in Quebec (18.49/year/100 000 children under 5 years of age) was 4–12 times higher than reported in their countries of origin- Tunisia, Morocco, and Algeria (0.95, 4.52, and 3.15, respectively) suggesting a likelihood of under-diagnosis. This case series sought to highlight the characteristics, presentation, and management of patients diagnosed with kDa in a tertiary hospital in Kenya. Methods This was a retrospective cross-sectional study carried out by reviewing the charts of all the patients with a discharge diagnosis of kDa from January 2013 to December 2017 at the Aga Khan University Hospital, Nairobi. Their demographics, presentation, diagnostic work-up, and management are reported. Analysis was done by descriptive statistics using the Microsoft Excel 2016 Application. Results A total of 15 cases were identified and the patient characteristics and presentation are as tabulated below: In addition to elevated inflammatory markers (C reactive protein and/or Erythrocyte Sedimentation Rate), a significant number of the patients also had sterile pyuria (9/9), hypoalbuminemia (8/10), thrombocytosis (8/15), and anaemia (11/15). Nine out of eleven had negative blood cultures. Fourteen out of the fifteen patients had echocardiograms done during admission. Only one patient was found to have abnormal findings of bilaterally dilated coronaries arteries. Five patients had at least one documented repeat echocardiogram. Fourteen patients received Intravenous Immunoglobulin (IVIG), with 13 of them responding to treatment. No adverse effects were reported after treatment. One patient did not improve and needed a second dose of IVIG and intravenous methylprednisone (30 mg/kg). Fourteen patients received aspirin but dosing varied from high (80–90 mg/kg/day) to moderate (30–50 mg/kg/day) to low dose (3 mg/kg/day). One patient on high-dose aspirin was noted to have developed symptoms consistent with aspirin-induced bronchospasm and was changed to low dose. Conclusion This case series highlights the presence of kDa in the Kenyan pediatric population with patient characteristics similar to what is reported globally. Diagnosis was made after a mean of about 7 days, possibly due to low awareness of the disease among healthcare professionals. Management with IVIG in most cases was successful but more guidance is needed around the use of steroids and the dosing of aspirin.

Pathology of Angiostrongylus cantonensis infection in two model avian hosts

Parasitology ◽  
2020 ◽  
pp. 1-4
Author(s):  
Barbora Fecková ◽  
Priyanka Djoehana ◽  
Barbora Putnová ◽  
Michaela Valašťanová ◽  
Michaela Petríková ◽  
...  
Keyword(s):  
Low Dose ◽  
Natural Infection ◽  
Clinical Signs ◽  
French Polynesia ◽  
Angiostrongylus Cantonensis ◽  
High Dose ◽  
Wide Range ◽  
The Central Nervous System ◽  
Gross Lesions ◽  
Natural Pest Control

Abstract Angiostrongylus cantonensis causes severe neurological disorders in a wide range of warm-blooded animals, including several avian species. A laboratory isolate of A. cantonensis originating from French Polynesia, genotyped as clade 2, was used to assess the effect of experimental infection in chicken and Japanese quail. Low dose groups of birds were infected orally by 100 L3 larvae, high dose groups by 1500 L3 larvae and the birds in the third group were fed three infected snails, mimicking a natural infection. Clinical signs during the first week after infection, haematology, biochemistry, gross lesions and histology findings were used to assess the pathology of the infection. Some of the infected birds showed peripheral eosinophilia, while mild neurological signs were seen in others. No larvae were observed in serial sections of the central nervous system of infected birds 1 week after infection and no major gross lesions were observed during necropsy; histopathology did not reveal lesions directly attributable to A. cantonensis infection. Our results suggest that galliform birds are not highly susceptible to A. cantonensis infection and open a question of the importance of Galliformes in endemic areas as natural pest control, lowering the number of hosts carrying the infective larvae.

Intranasal Scopolamine for Motion Sickness

2019 ◽  
Vol 90 (11) ◽  
pp. 917-924
Author(s):  
Aleksandra S. Stankovic ◽  
Donna L. Alvarenga ◽  
Vernie R. Coleman Daniels ◽  
Rita G. Simmons ◽  
Jay C. Buckey ◽  
...  
Keyword(s):  
Motion Sickness ◽  
Intranasal Administration ◽  
Low Dose ◽  
Small Sample Size ◽  
Vertical Axis ◽  
Rapid Onset ◽  
Small Sample ◽  
High Dose ◽  
Double Blind ◽  
Axis Rotation

INTRODUCTION: Rapid onset, noninjection methods are required to provide “as needed” therapy for motion sickness. Intranasal scopolamine (IN SCOP) is attractive because it can be fast acting and work when gastric motility is slowed. Intranasal administration can provide a time to maximal concentration (Tmax) of drugs (e.g., naloxone and midazolam) of 30 min or less. We evaluated the efficacy, pharmacodynamics, and pharmacokinetics of IN SCOP in a placebo-controlled, randomized, double-blind, dose-ranging study, and compared pharmacokinetic outcomes against other published results.METHODS: There were 18 healthy adult volunteers (10 M, 8F) who received placebo, low dose (0.2 mg), and high dose (0.4 mg) IN SCOP intranasally using a pump device and a gel formulation. Participants rode in an off-vertical axis rotation (OVAR) chair 1.25 h after dose administration and completed neurocognitive tests to evaluate secondary drug impacts. Pharmacokinetics (PK) and pharmacodynamics (PD) were assessed in eight subjects. PK data were compared to results from previously published studies.RESULTS: Low and high dose IN SCOP increased chair time significantly compared to placebo. No significant sleepiness or cognitive impairment was seen, likely due to the small sample size. Tmax was long for both dosages (High dose 75.0 ± 49.4 min, Low dose 61.9 ± 37.1 min), compared to other intranasally administered drugs and some previous studies with IN SCOP. Average Tmax was not superior to previously published values for dose-matched (0.4–0.5 mg), orally-delivered SCOP.DISCUSSION: IN SCOP has potential as a rapid administration route for relieving MS symptoms, but more work is needed to identify optimal intranasal formulation and dispensing methods.KEYWORDS: Motion sickness, pharmacokinetics, scopolamine, intranasal administration.Stankovic AS, Alvarenga DL, Daniels VRC, Simmons RG, Buckey JC, Putcha L. Intranasal scopolamine for motion sickness. Aerosp Med Hum Perform. 2019; 90(11):917–924.

scholarly journals Subclinical Prion Disease Induced by Oral Inoculation

2003 ◽  
Vol 77 (14) ◽  
pp. 7991-7998 ◽  
Author(s):  
Alana M. Thackray ◽  
Michael A. Klein ◽  
Raymond Bujdoso
Keyword(s):  
Nervous System ◽  
Protein Expression ◽  
Prion Disease ◽  
Clinical Signs ◽  
Oral Route ◽  
Wild Type ◽  
Subclinical Disease ◽  
Oral Inoculation ◽  
The Central Nervous System ◽  
Peripheral Infection

ABSTRACT Natural transmission of prion disease is believed to occur by peripheral infection such as oral inoculation. Following this route of inoculation, both the peripheral nervous system and the lymphoreticular system may be involved in the subsequent neuroinvasion of the central nervous system by prions, which may not necessarily result in clinical signs of terminal disease. Subclinical prion disease, characterized by the presence of infectivity and PrPSc in the absence of overt clinical signs, may occur. It is not known which host factors contribute to whether infection with prions culminates in a terminal or subclinical disease state. We have investigated whether the level of host PrPc protein expression is a factor in the development of subclinical prion disease. When RML prion inoculum was inoculated by either the i.c. or intraperitoneal route, wild-type and tga20 mice both succumbed to terminal prion disease. In contrast, orally inoculated tga20 mice succumbed to terminal prion disease, whereas wild-type mice showed no clinical signs. However, wild-type mice sacrificed 375 or 525 days after oral inoculation harbored significant levels of brain PrPSc and infectivity. These data show that same-species transmission of prions by the oral route in animals that express normal levels of PrPc can result in subclinical prion disease. This indicates that the level of host PrPc protein expression is a contributing factor to the regulation of development of terminal prion disease. Events that increase PrPc expression may predispose a prion-infected animal to the more deleterious effects of prion pathology.

Subchronic Oral Toxicity Study of Mixed Tocopheryl Phosphates in Rats

2007 ◽  
Vol 26 (5) ◽  
pp. 475-490 ◽  
Author(s):  
R. Gianello ◽  
W. C. Hall ◽  
E. Kennepohl ◽  
R. Libinaki ◽  
E. Ogru
Keyword(s):  
Small Intestine ◽  
Lymph Node ◽  
Low Dose ◽  
Clinical Chemistry ◽  
Clinical Signs ◽  
Female Rats ◽  
High Dose ◽  
Test Substance ◽  
Foreign Material ◽  
Dose Dependent

Rats were fed diets containing 0%, 1 %, 3%, or 5% mixed tocopheryl phosphates for 90 days. No abnormal clinical signs related to treatment appeared. Some statistically significant changes in hematology and clinical chemistry parameters appeared, but the majority were not dose dependent, occurred in only one sex or group, and/or remained within the historical control range for this strain of rat. A statistically significant apparent reduction in blood protein was observed in animals treated with the tocopheryl phosphates, but further investigation showed that the test substance interfered with the protein assay. Repeat analysis using a method unaffected by plasma test substance levels showed no difference in plasma proteins among all groups. Gross necropsy revealed no abnormalities; reduced relative heart and epididymal weights were observed, but were not dose dependent and were considered incidental. Histopathological changes occurred only in the mesenteric lymph node and small intestine. Foreign material in a crystal-like form appeared in macrophages in both organs, and increased in a dose-related fashion. In the lymph node, sinus histiocytosis increased with dose, but the severity was similar between the control and low-dose groups. Foreign-body granulomatous inflammation, associated with Maltese cross birefringence of the crystals was seen in the mid- and high-dose animals, but not the low-dose group. Similarly, the small intestine showed increasing amounts of foreign material and inflammation in the mid- and high-dose but not in the 1 % diet. The 1 % diet (equivalent to 587 and 643 mg mixed tocopheryl phosphates/kg body weight/day for male and female rats, respectively) was considered the no observed adverse effect level.

scholarly journals Efficacy of the Investigational Antifungal VT-1161 in Treating Naturally Occurring Coccidioidomycosis in Dogs

2017 ◽  
Vol 61 (5) ◽  
Author(s):  
Lisa F. Shubitz ◽  
Michael E. Roy ◽  
Hien T. Trinh ◽  
William J. Hoekstra ◽  
Robert J. Schotzinger ◽  
...  
Keyword(s):  
Low Dose ◽  
Plasma Concentrations ◽  
Clinical Signs ◽  
Weighted Average ◽  
Response To Treatment ◽  
Preclinical Model ◽  
High Dose ◽  
Open Label ◽  
Naturally Occurring ◽  
Reduced Toxicity

ABSTRACT Coccidioidomycosis can be a chronic, systemic fungal infection requiring long-term to lifetime medication. Thus, there is a need for improved antifungal agents with greater efficacy and reduced toxicity. VT-1161 has a low affinity for mammalian cytochromes and potently inhibits fungal CYP51 with proven efficacy in murine models of central nervous system (CNS) and respiratory coccidioidomycosis. Dogs experience coccidioidomycosis similar to humans and are a useful preclinical model for naturally occurring disease. Twenty-four client-owned dogs diagnosed with respiratory coccidioidomycosis based on radiography, serology, clinical signs, and clinicopathologic abnormalities were treated with a loading dose of VT-1161 for 14 days, followed by 46 days of a lower maintenance dose. Twelve dogs received a high dose (29 mg/kg loading, 6 mg/kg maintenance) and 12 received a low dose (10 mg/kg loading, 1.6 mg/kg maintenance). Response to treatment was assessed by calculating the reduction in disease scores at exit compared to disease scores at enrollment. Overall, 20 of 24 (83%) dogs had ≥50% reduction in enrollment disease scores at exit (P < 0.001), with no difference between the high- and low-dose groups (P = 0.66). Time-weighted average plasma concentrations for the high- and low-dose groups were 39 ± 5 μg/ml and 19 ± 2 μg/ml, respectively. In this open-label study, VT-1161 was efficacious for the treatment of respiratory coccidioidomycosis in naturally infected dogs. Combined with previously reported murine data, this finding supports the further development of VT-1161 for the treatment of coccidioidomycosis in humans.

Smokeless Tobacco: an Addicting Drug

1997 ◽  
Vol 11 (3) ◽  
pp. 330-335 ◽  
Author(s):  
J.E. Henningfield ◽  
R.V. Fant ◽  
S.L. Tomar
Keyword(s):  
Smokeless Tobacco ◽  
Low Dose ◽  
Drugs Of Abuse ◽  
Clinical Signs ◽  
High Dose ◽  
Delivery Device ◽  
Surgeon General ◽  
Nicotine Tolerance ◽  
Repeated Use ◽  
Addictive Drug

In 1986, the Surgeon General concluded that smokeless tobacco is an addictive drug sharing many qualities with other drugs of abuse such as morphine and cocaine. Smokeless tobacco can be used to deliver psycho-active and dependence-producing levels of nicotine. Tolerance develops with repeated use, causing the user to increase nicotine dosing through increased use and/or switching to products with higher nicotine yields. Clinical signs of nicotine withdrawal develop upon cessation of use. Recent data show that smokeless tobacco products vary widely in their nicotine dosing capabilities. Low-dose products tend to be those commonly marketed toward, and used by, young people without previous smokeless tobacco experience. Many of these people develop dependence and switch to high-dose products. The present article discusses each of these qualities of smokeless tobacco in greater detail. The article also discusses qualities of smokeless tobacco that make it an effective nicotine delivery device that leads to addiction.

scholarly journals Effects of Resveratrol on the Mechanisms of Antioxidants and Estrogen in Alzheimer’s Disease

2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Danli Kong ◽  
Yan Yan ◽  
Xiao-Yi He ◽  
Huihuang Yang ◽  
BiYu Liang ◽  
...  
Keyword(s):  
Protein Expression ◽  
Western Blot ◽  
Brain Tissue ◽  
Low Dose ◽  
Mrna Level ◽  
High Dose ◽  
Model Group ◽  
Protein Levels ◽  
Mda Content ◽  
The Brain

Objective. To observe the effects of resveratrol (Res) on the antioxidative function and estrogen level in an Alzheimer’s disease (AD) mouse model. Methods. First, we examined the effects of Res on an AD mice model. SAMP8 mice were selected as the model, and normal-aging SAMR1 mice were used as the control group. The model mice were randomly divided into three groups: a model group, high-dose Res group (40mg/kg, intraperitoneal (ip)), and low-dose Res group (20mg/kg, ip). After receiving medication for 15 days, the mice were subjected to the water maze test to assess their spatial discrimination. The spectrophotometric method was used to detect the activity of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and catalase (CAT) as well as the malondialdehyde (MDA) content. Quantitative PCR (q-PCR) was used to detect SOD, GSH-Px, CAT, and heme oxygenase-1 (HO-1) mRNA level changes. Western blot analysis detected HO-1 and Nrf2 protein expression. Second, we researched the effect of Res on the estrogen level in the SAMP8 model mice. The model mice were randomly divided into four groups: a model group, estrogen replacement group (0.28 mg/kg, intramuscular (im), estradiol benzoate), high-dose Res group (5 mg/kg, im), and low-dose Res group (2.5 mg/kg, im). The mice were injected, once every three days, for 5 weeks. Q-PCR was used to detect brain tissue mRNA expression changes. Western blot analysis detected ERα, ERβ, and ChAT protein expression. An enzyme-linked immunosorbent assay (ELISA) kit was used to detect the expression of E2 and amyloid β protein (Aβ) in brain tissue. Results. Compared with the control treatment, Res could improve the spatial abilities of the mice to a certain extent and also increase the expression of SOD, GSH-Px, CAT, and HO-1 at the mRNA level (P<0.05). In addition, enhanced SOD, GSH-Px, and CAT activities and HO-1 protein levels and decreased MDA content (P<0.05) were detected in the brain tissue of the Res-treated mice. The cytoplasmic Nrf2 content in the Res-treated mice was also decreased while the nuclear Nrf2 content and the nuclear translation rate of Nrf2 were increased (P<0.05). Res could decrease the expression of ERβ in the brain tissue at the mRNA and protein levels and the expression of Aβ in the brain tissue at the protein level. Res could also increase the mRNA and protein expression of ERα and ChAT and the protein expression of estradiol in the brain tissue. Conclusion. Res can increase the antioxidant capacity of AD models through the Nrf2/HO-1 signaling pathway. In addition, Res can enhance estrogen levels in an AD model. These findings provide a new idea for the treatment of AD.

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