Efficacy of Fenbendazole and Ivermectin against Trichuris spp. in African Green Monkeys (Chlorocebus sabaeus) in Barbados West Indies

Trichuris spp. are common helminths in NHP, and benzimidazoles and avermectins have both been used to treat these intestinal parasites. The current study compared the efficacy of fenbendazole and ivermectin against natural infection of Trichuris spp. in African green monkeys (Chlorocebus sabaeus). Anthelmintic-naive animals (n = 65) were randomly assigned to 4 groups: an untreated control group, and 3 groups treated with either fenbendazole, ivermectin, or both compounds. Fecal samples were collected before treatment and on days 7, 14, 28, and 60 after treatment, and fecal egg counts (FEC) were determined by using fecal flotation. The mean percentages of FEC reduction at day 60 were 100%, 86%, and 100% for treatment with fenbendazole, ivermectin, and both compounds, respectively. Analyzing the time series of FEC by using a Bayesian generalized linear model showed no significant difference in the proportional reduction in FEC among the 3 treatment groups, although all FEC from treated groups were significantly lower than the FEC of the control group. In contrast, the probability of shedding was highest in the ivermectin group and the lowest in the animals treated with both compounds. The probability of shedding differed significantly between the fenbendazole and ivermectin groups and between the ivermectin and combined-treatment groups. In conclusion, both fenbendazole and ivermectin are effective anthelmintics in treating Trichuris spp. infection in African green monkeys. All treatment groups showed significant reductions in FEC when compared with baseline counts and control animals; however, fenbendazole may be more effective than ivermectin when used solely or in combination with other anthelmintic treatments.

Trichuris spp. (whipworms) from the family Trichuridae are common soil-transmitted gastrointestinal nematodes with a worldwide distribution in mammals.⁷ Trichuris trichiura is the whipworm species that commonly infects humans and NHP,¹⁸ but morphologic and biometrical studies have yielded results suggesting that other Trichuris species may also be present in NHP.^6,11,53Trichuris spp. have a direct life cycle, with eggs transmitted via the fecal–oral route with infection occurring from ingestion of embryonated eggs in contaminated food, soil, and water.⁴⁸ Under optimal environmental conditions, Trichuris spp. eggs can remain viable in infected soil for years.²³ After ingestion, the released L1 larvae molt and travel to the cecum and colon, where they bury into the epithelia and develop into adults. After mating, the unembryonated eggs are released from the female and are deposited into the environment in the host feces.^7,13 Light infection is asymptomatic; however severe infection produces clinical signs such as severe enteritis, anorexia, gray mucoid diarrhea, and sometimes death.⁵The prevalence of Trichuris spp. (whipworms) in NHP usually is high,⁴⁹ and species in this genus are commonly found in Old World NHP, including African green monkeys (AGM), baboons, macaques, and sykes.^39,54 High prevalence rates ranging from 60% to 98% have been recorded in wild populations,^30,39,42 and prevalence rates ranging from 30% to 79% have been found in captive colonies of NHP in zoological parks and research facilities.^1,26,39,50 In the Caribbean, a study of captive AGM in St Kitts⁵⁴ revealed a prevalence of 91%, whereas 53% was recorded in recently captured wild AGM in Barbados.⁴⁰AGM (Chlorocebus sabaeus) are the only wild NHP species found on the island of Barbados. These animals were introduced into the island soon after it was colonized in 1627.³ Populations are also found on the islands of St Kitts-Nevis, St Maarten/Martin, and Tortola.¹⁴ AGM are used widely in biomedical research²⁵ for studies on hypertension,¹⁵ neurologic disease^20,34 and vaccine production.^36,52 In a research setting, NHP should be parasite-free²⁴ for the sake of the animal’s health (which in turn affects research outcomes) and to eliminate possible risk of transfer of zoonoses to caregivers and other research facility personnel.Different classes of drugs have been used to treat Trichuris spp. infection in NHP, including benzimidazoles like fenbendazole, mebendazole, and albendazole,^45,46,55 and avermectins.^27,51 Studies have been conducted using these drugs in macaques, vervets, baboons, and langurs.^{21,27,38,44,51} Fenbendazole and ivermectin have been used at various doses in the treatment of Trichuris infection in NHP. Fenbendazole has been administered at doses of 10 to 50 mg/kg PO daily for 3 to 5 d, with or without repeated doses.^16,38,44,45 Ivermectin has been administered at doses of 100 to 400 µg SC, IM, or PO as a single dose or at specified intervals.^21,24,38,51 Little published data exist regarding the use of these drugs specifically in AGM. The current study was conducted to compare the efficacy of fenbendazole and ivermectin—alone and in combination—against Trichuris spp. in naturally infected AGM in Barbados, West Indies, for clearance of this parasite.     

四种黄芪注射液中黄芪甲苷含量比较

目的：考察不同厂家黄芪注射液的内在质量。方法：用高效液相色谱法测定黄芪甲苷的含量。结果：建立的方法适用于黄芪注射液中黄芪甲苷的含量测定、快速,灵敏,重 现性好。结论：不同厂家产品差异显著。     

Lymphoscintigraphy, Sentinel Lymph Node Biopsy, and Mohs Micrographic Surgery in the Treatment of Merkel Cell Carcinoma

BACKGROUND: Merkel cell carcinoma (MCC) is an aggressive cutaneous malignancy with a high incidence of occult nodal metastases. MCC is believed to be similar in natural history to thick or ulcerated melanomas in its propensity for locoregional recurrence and early lymph node metastasis. Studies have shown that nodal status is statistically correlated to survival in MCC. Radiolocalization and superselective lymph node biopsy is a recent technique that has been proven to be of great value in evaluating the status of occult lymph node disease in malignant melanoma and breast cancer patients. OBJECTIVE: In previously untreated patients, an orderly progression of metastases is observed for both cutaneous carcinomas and malignant melanomas and is anticipated for MCC. METHODS/RESULTS. We present two patients with MCC of the head and neck who underwent simultaneous Mohs micrographic surgery and sentinel lymph node biopsy with intraoperative radiolocalization. CONCLUSION: Sentinel lymph node biopsy and intraoperative lymphoscintigraphy may prove to be a useful technique in evaluating occult nodal involvement and in limiting the potentially unnecessary morbidity of more comprehensive lymph node dissections in MCC patients who do not yet have metastatic involvement.     

Detection of a common mutation in factor V gene responsible for resistance to activated protein C causing predisposition to thrombosis

Hereditary predisposition to thrombosis due to activated protein C resistance (APCR) has been attributed to a missense mutation in the factor V gene at nucleotide 1691 (G to A), causing replacement of arginine at codon 506 with glutamine. Using an RFLP-PCR assay to detect this mutation, we measured a prevalence of 3.3% in healthy Caucasians and 1.25% in healthy African-Americans. In addition, we evaluated a total of 90 consecutive specimens submitted to the coagulation laboratory at the Medical College of Virginia for the presence of this mutation. We compared our results for 78 of these specimens with the values measured by a modified partial thromboplastin assay, the COATEST. Twelve of the 90 samples could not be tested using the COATEST because the patients were undergoing anticoagulant therapy. One of the latter 12 specimens was positive by the RFLP-PCR test. Using the genetic test as the definitive assay and the cutoff value established for distinguishing between normal and abnormal results by the COATEST, the COATEST had a sensitivity of 50% and specificity of 93% for the detection of factor V mutation. Analysis of the 90 samples stratified by ethnic groups revealed a frequency of mutation of 13.3% for Caucasians and 6.88% for African-Americans, although with the present sample size, the difference was not statistically significant. Although the COATEST is technically simpler to perform than the genetic test for diagnosing the presence of the factor V mutation, its use for this purpose is limited due to low sensitivity. Thus where this disorder is clinically suspected, submission of the specimen directly for genetic testing by RFLP-PCR or equivalent assay should be considered. J. Clin. Lab. Anal. 11:328–335, 1997. © 1997 Wiley-Liss, Inc.     

Constrictive pericarditis and restrictive myocardiopathy]

The purpose of this study was to assess the clinical and echocardiographic characteristics of constrictive pericarditis (CP) and restrictive cardiomyopathy (RC) and to compare them with the results obtained with cardiac catheterization. Clinical history, electrocardiogram and X-ray were taken in all patients, and transthoracic and transesophageal echocardiography were performed. Cardiac catheterization with transmyocardial biopsy was performed on only 5 patients. Wall thickness and left ventricular dimensions were normal in all patients with CP. Wall thickness was increased in those with RC. No patients demonstrated alterations in segmental wall movement. The pericardium was thickened and abnormally bright in the 3 patients with CP. In patients with CP the percentage of atrioventricular, semilunar, pulmonary and hepatic flow changes with respiration were more than 10%. In patients with RC this flow variation was less notable. However, the percentage of systolic and diastolic flow velocity increase of hepatic veins during expiration was greater than in CP. We can conclude that M-mode, two dimensional and Doppler echocardiography is extremely useful noninvasive method to differentiate CP and RC with good correlation with cardiac catheterization.     

Quadricuspid aorta diagnosed by transesophageal echocardiography. A case report]

We report a case of a 64 year-old woman who had a quadricuspid aortic valve associated with aortic regurgitation of mild degree diagnosed by transesophageal echocardiography (TEE). The four cuspids were of the same size. This valve anomaly could not be diagnosed by transthoracic echocardiogram (TTE). The TEE is a diagnostic noninvasive procedure that gives the best information in quadricuspid aortic valve malformation.     

脑栓塞患者主动脉斑块的临床意义

目的 探讨脑栓塞患者的主动脉弓动脉粥样硬化（ＡＡＡ）严重程度及其有关的危险因素,方法 对１００例脑梗塞患者进行了ＴＣＤ,经食道超声心动图（ＴＥＥ）,颈动脉超声心动图,ＣＴ及ＭＲＩ等检查。结果 ７５例患者伴有ＡＡＡ,其中３４例为中－重度ＡＡＡ,年龄,吸烟,冠心病,糖尿病,颈内动脉阻塞性痴呆病以及栓塞源性心脏病与ＡＡＡ呈明显的正相关;１２例在病变侧发现有高度的颈内动脉狭窄,２８例伴有栓塞性的心脏疾病,     

Adult mammalian forebrain ependymal and subependymal cells demonstrate proliferative potential, but only subependymal cells have neural stem cell characteristics

The adult derivatives of the embryonic forebrain germinal zones consist of two morphologically distinct cell layers surrounding the lateral ventricles: the ependyma and the subependyma. Cell cycle analyses have revealed that at least two proliferating populations exist in this region, one that is constitutively proliferating and one that is relatively quiescent and thought to include the endogenous adult neural stem cells. Earlier studies demonstrated that specific dissection of the region surrounding the lateral ventricles was necessary for the in vitro isolation of multipotent, self-renewing neural stem cells. However, in these studies, the ependymal layer was not physically separated from the subependymal layer to identify the specific adult laminar localization of the neural stem cells around the lateral ventricles. To determine which cellular compartment in the adult forebrain contained the neural stem cells, we isolated and cultured the ependyma separately from the subependyma and tested for the presence of neural stem cells using the in vitro neurosphere assay. We demonstrate that the ependymal cells can proliferate in vitro to form sphere-like structures. However, the ependymal cells generating spheres do not have the ability to self-renew (proliferate to form secondary spheres after dissociation) nor to produce neurons, but rather only seem to generate glial fibrillary acidic protein-positive ependymal cells when plated under differentiation conditions in culture. On the other hand, a subpopulation of subependymal cells do possess the self-renewing and multipotential characteristics of neural stem cells. Therefore, the adult forebrain neural stem cell resides within the subependymal compartment.