Mike to John Philip Trinkaus, March 1, 2000

Letter from Mike to Trinkaus, mentioning the Embryology course at Woods Hole 1957.Printed copy of email correspondence1-pageCorrespondenc

EVALUATION OF THE PRESENCE OF THE HEAVY METAL NICKEL IN SAMPLES OF TOBACCO SNUFF (NICOTIANA TABACUM) IN NIGERIA

Objective: Tobacco snuffs a finely ground dark brown coloured powder obtained from dried pulverized leaves of tobacco plant Nicotianatabaccum is commonly used among Nigerians. Since the nickel content and its health implications are not known to have been studied, this study evaluates the presence of this heavy metal in some samples of tobacco snuff obtained from four geopolitical zones of Nigeria.Methods: The study was conducted using thirty samples of tobacco snuff obtained from different parts of Nigeria. The samples were tested for the presence of the heavy metal Nickel by Atomic Absorption Spectrometry.Results: All the samples contain the heavy metal nickel. Nickel concentration in the studied samples ranged from 0.0003–0.0011 μmol/g, with the highest concentration found in the sample number 3 and 22 only.Conclusion: Tobacco snuff samples sourced from various geopolitical zones of Nigeria are highly contaminated with the heavy metal Nickel.Keywords: Evaluation, Nickel, Tobacco snuff, Nigeria

Mike to John Philip Trinkaus, February 25, 2000

Letter from Mike to Trinkaus, telling him how much he enjoyed Trinkaus's course on comparative vertebrate zoology at Yale, 46 years ago.Printed copy of email correspondence1-pageCorrespondenc

IN VITRO EVALUATION OF THE NON-CYTOTOXIC THYMUS CAPITATUS EXTRACTS INHIBIT BOVINE HERPESVIRUS-1 EXPANSION

Objective: Bovine herpes virus type 1 (BHV-1) is an important cofactor in the bovine respiratory disease complex with high health and financial impact because there aren't any available drugs that proved to be fully effective against it. In this study, the cytotoxicity and antiviral activities of the Thymus capitatus extracts were evaluated for the development of new, non toxic and specific anti-herpesvirus agents.Methods: The aqueous extracts (AE), ethanolic extracts (EE) and essential oil (EO) of the aerial parts of Thymus capitatus were analyzed to determine their chemical compositions by gas chromatography, and high performance liquid chromatography combined with mass spectrometry. Their cytotoxicity, and antiviral activities against Bovine Herpesvirus type 1 (BHV-1) were evaluated by quantifying the reduction of the viral cytopathic effect using Madin-Darby Bovine Kidney cell line with the colorimetric assay. T. capitatus extracts were added at different stages of the viral infection to investigate and better quantify their potential inhibitory effects.Results: Polyphenols and flavonoids were the major compounds found in T. capitatus EO, EE and AE. The cytotoxic concentrations at 50 % were 48.70, 189 and 289 µg ml-1 for EO, EE and AE respectively. The inhibitor concentrations at 50 % for the EO, EE and AE, were 3.36, 47.80 and 164 μg ml-1, respectively. The selectivity index anti-BHV-1 values were 14.49, 3.95 and 1.81 for EO, EE and AE respectively. Thus the EO extracts were the most efficient antiviral compounds. T. capitatus extracts affect mainly the adsorption of BHV-1 virus to host cells. Conclusion: T. capitatus extracts inhibit the viral replication by interfering with the early stages of viral adsorption and replication. Thus, T. capitatus is a potential candidate for anti-herpes virus treatment.Keywords: Thymus capitatus, Cytotoxicity, Antiviral, Madin-Darby Bovine Kidney cell, Bovine herpesvirus type1