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Issue 1, Volume 9, January
2012
Title
of the Paper:
Determination of Amoxicillin in Human Plasma by LC-MS/MS and its Application
to a Bioequivalence Study
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Authors:
Satish G. Pingale, Madhukar A. Badgujar, Kiran V. Mangaonkar, Nikos E.
Mastorakis
Abstract: An analytical method based on solid phase extraction has been
developed and validated for analysis of amoxicillin in human plasma using
gemifloxacin as an internal standard. A COSMOSIL 5C18-PAQ column provided
chromatographic separation of analytes followed by detection with mass
spectrometry. The method involves simple isocratic chromatographic conditions
and mass spectrometric detection in the positive ionization mode using an
API-3000 system. The proposed method has been validated with linear range of
100–15000 ng/mL for amoxicillin. The intra-run and inter-run precision values
are within 3.53% and 5.63% respectively for amoxicillin at the LOQ level.
Total elution time was as low as 2 min. This validated method was used
successfully for analysis of plasma samples from a bioequivalence study.
Keywords: Amoxicillin, Antibiotic, Automated solid phase extraction,
Tandem mass spectrometry, Human plasma, Bioequivalence study
Title
of the Paper:
A Plausible Route to a Prebiotic Synthesis of L-Histidine
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Authors:
N. Aylward
Abstract: Possible reactions in a mildly reducing prebiotic atmosphere of
ammonia and hydrogen cyanide produce cyanamide, its isomer carbodiimide, and
formamidine. Alkynes such as diacetylene may form very weak van der Waals
complexes with metal derivatives of porphin that acts as a potent
photochemical catalyst. The reactants carbodiimide and the diacetylene adduct
with magnesium porphin may react spontaneously to form an iminazole structure.
Subsequent reaction with ammonia leads to an aziridine derivative. Prototropic
shifts lead to an opening of the ring and finally an imine bound to the
catalyst. Carbon monoxide gas may also bind to porphin with either the metal
ion or in the form of an aziridine-2one complex. If this has been determined
by the magnetic field of the exciting ultraviolet radiation to have a
particular orientation and is present as a high energy compound, photochemical
excitation may easily lead to the migration of the carbon monoxide from the
surface of the porphin ring to the imine group of the iminazole adduct.
Subsequent hydrolysis gives the L-histidine which forms the zwitterion.
The reactions have been shown to be feasible from the overall enthalpy changes
in the ZKE approximation at the HF and MP2 /6-31G* level, and with acceptable
activation energies.
Keywords: L-histidine, diacetylene, carbodiimide, formamidine,
cyanamide
Title
of the Paper:
Patient Variables Determining Treatment Protocol and Related Economical Impact
in Occupational Rotator Cuff Tears
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Authors:
Amaryllis Audenaert, Els De Mey, Genserik Reniers
Abstract: Rotator cuff tears occur in almost three percent of all industrial
accidents in Belgium. There are two treatment options for this type of injury:
the non-surgical or ‘conservative’ option and the considerably more expensive
surgical option. As the total cost associated with the treatment of rotator
cuff tears has, over the past ten years, risen considerably in Belgium, we
tried to identify variables that are related to an increased risk for need of
such surgical treatment.
The objective of this study is to evaluate the use of different treatment
options and their economic impact following rotator cuff tearing resulting
from an occupational accident in the Belgian context.
Patient age and rupture size were interrelated and both significantly
associated with need for surgical treatment and prolonged temporarily and even
permanent disability with increasing social and medical costs. Occupation
type, although itself a risk factor for the development of rotator cuff tears,
was not significantly associated with increased need for surgical treatment.
Keywords: Rotator cuff rupture, economic evaluation, conservative
treatment, surgical treatment, cost modelling of medical treatments
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