Human imaging of phosphorus in cortical and trabecular bone in vivo.

Phosphorus was imaged in vivo in human cortical and trabecular bone and the T(1) and T(2) (*) were measured. An ultrashort TE (UTE) pulse sequence (TE = 70 microm) was used with half pulse excitation and radial mapping of k-space from the center out. T(2) (*) was measured using multiple echo times and T(1) was measured both by saturation recovery and by a method using different RF pulse amplitudes. Seven normal subjects (32-85 years) were examined. Phosphorus was imaged, with a true in-plane resolution of 2.9 x 2.9 mm and a signal-to-noise ratio (SNR) of 19:1, in both cortical and trabecular bone. The mean T(2) (*) value was 207 +/- 12 micros, and the mean T(1) value was 8.6 +/- 3.0 sec. Images and measurements were obtained in realistic times on a clinical MR system. This may provide a new approach to characterizing disease of bone.     

Histidine-rich protein genes and their transcripts in Plasmodium falciparum and P. lophurae

The presence of histidine-rich protein (HRP) related genes and gene products in Plasmodium falciparum was demonstrated using a synthetic pentahistidine-encoding oligonucleotide and a cloned HRP cDNA probe prepared from the avian parasite P. lophurae. In Northern blotting experiments, two knobby clones of P. falciparum were found to contain a 3500 nucleotide RNA species that hybridized with the oligonucleotide and HRP cDNA probes. As this component had the expected size for an mRNA encoding an 80-90 kDa protein and was absent from two knobless clones of P. falciparum, we concluded that it represented a 'knob protein' mRNA. Using the restriction enzyme EcoRI, three identical cross-hydribizing HRP gene fragments were found in the DNA of both knobby and knobless clones of P. falciparum. These fragments differed in size from those present in P. lophurae. These results suggest that the absence of knob protein mRNA in knobless clones is not due to loss of the corresponding gene(s).     

Cholinergic responses in cloned human TE671/RD tumour cells

The cholinergic responses of the human tumour cell line TE671/RD were examined using digital Ca²⁺ imaging fluorescence microscopy and patch-clamp measurements. In response to stimulation of the muscarinic acetylcholine (ACh) receptor (mAChR), the intracellular concentration of Ca²⁺ ([Ca²⁺]_i) rose about two-fold, in parallel with inositol 1,4,5-trisphosphate accumulation, measured by chromatographic techniques. By contrast, there was no increment of [Ca²⁺]_i upon stimulation of the nicotinic ACh receptor (nAChR), nor after caffeine application. Electrophysiological experiments showed that TE671/RD cells lack functional voltage-activated Ca²⁺ channels. The stimulation of the nAChR induced transient whole-cell currents (I _ACh). Little or no current was detected in isotonic extracellular Ca²⁺, with Cs⁺ in the patch pipette. Cell pretreatment with muscarine reduced I _ACh by about 20%, without consistent modifications of current kinetics. Muscarine applied to the extra-patch membrane under the cell-attached configuration had no obvious effect on ACh-evoked unitary events. In conclusion, in human TE671/ RD cells, muscarinic stimulation increases [Ca²⁺]_i, while nicotinic stimulation does not. In addition, the nAChR exhibits peculiar ion permeability properties and is not functionally regulated by the breakdown of phosphoinositides.     

Reactivity of a monoclonal antibody produced to the histidine-rich protein of Plasmodium lophurae with Plasmodium falciparum

Monoclonal antibodies were produced against the histidine-rich protein of Plasmodium lophurae and tested for reactivity with Plasmodium falciparum antigens. One anti-histidine-rich protein monoclonal antibody showed immunological cross-reactivity with polypeptides of P. falciparum synthesized in vivo and in vitro.     

The effects of feeding an Asian or Western diet on sperm numbers, sperm quality and serum hormone levels in cynomolgus monkeys (Macaca fascicularis) injected with testosterone enanthate (TE) plus depot medroxyprogesterone acetate (DMPA)

The aim of this study was to elucidate the effects of an Asian diet compared to a Western diet on sperm numbers and quality, and serum hormones in cynomolgus monkeys (Macaca fascicularis) injected with testosterone enanthate (TE) plus depot medroxyprogesterone acetate (DMPA). Thirty male monkeys were divided into three groups of ten animals each. The first group (control) was fed with standard diet 'monkey chow' (9% fat, 13% protein, 78% carbohydrate); the second group was fed an 'asian' diet (15% fat, 15% protein, 70% carbohydrate); the third group was fed a 'Western' diet (35% fat, 25% protein, 40% carbohydrate). These diets were administered from the beginning (adaptation) until the experiment was terminated. Three months after the adaptation period, all groups were injected with 20 mg TE (once per week) and 25 mg DMPA (once every 6 weeks) for 18 weeks, while TE injections were continued for another 6 weeks. There were no differences in sperm numbers and quality, or in hormone levels between the first and second groups. In both of these groups azoospermia was achieved in 100% of animals, while in the third group only 70% achieved azoospermia. In all 3 groups, spermatozoa were once again detectable by week 33. However, by the end of the study at week 39, sperm numbers in the first and second groups reached only severe oligozoospermia (two animals remained azoospermic in the first group) while in the third group, numbers had returned to normozoospermia. The quality of spermatozoa during and after the treatment in the third group was better than in the first and second groups. Hormone concentrations decreased more rapidly in both the first and second groups, compared to the third group, while the recovery period was slower in the first and second groups, compared to the third group. It is concluded that different formula diets result in differential decreases in sperm numbers and quality, and in hormone concentrations in M. fascicularis injected with TE in combination with DMPA. Animals fed with either monkey chow or an Asian diet exhibited more severe and prolonged decreases in these parameters than did animals fed with a Western diet.     

A comparative study of short‐ and long‐TE 1H MRS at 3 T for in vivo detection of 2‐hydroxyglutarate in brain tumors

2‐Hydroxyglutarate (2HG) is produced in gliomas with mutations of isocitrate dehydrogenase (IDH) 1 and 2. The ¹H resonances of the J‐coupled spins of 2HG are extensively overlapped with signals from other metabolites. Here, we report a comparative study at 3 T of the utility of the point‐resolved spectroscopy sequence with a standard short TE (35 ms) and a long TE (97 ms), which had been theoretically designed for the detection of the 2HG 2.25‐ppm resonance. The performance of the methods is evaluated using data from phantoms, seven healthy volunteers and 22 subjects with IDH‐mutated gliomas. The results indicate that TE = 97 ms provides higher detectability of 2HG than TE = 35 ms, and that this improved capability is gained when data are analyzed with basis spectra that include the effects of the volume localizing radiofrequency and gradient pulses. Copyright © 2013 John Wiley & Sons, Ltd.     

MRI evaluation of fatty liver in day to day practice: Quantitative and qualitative methods

Intracellular fat accumulation is a common feature of liver disease. Steatosis is the histological hallmark of non-alcoholic fatty liver disease (NAFLD) but also may occur with alcohol abuse, viral hepatitis, HIV and genetic lipodystrophies, and chemotherapy. This condition is common in the Western population and is typically associated with obesity and the metabolic syndrome. Early diagnosis and early treatment of NAFLD are important to prevent the development of end-stage liver disease and cancer. In addition, liver fat is a risk factor for postoperative complications after liver resection and transplantation. MRI has become a primary modality to assess hepatic steatosis, both qualitatively and quantitatively. In this article we discuss various MRI methods for evaluation of hepatic steatosis.