Uroscopy in the 21st century: high-field NMR spectroscopy

From the experiments described, it can be seen that there are different research approaches that can be taken and these are summarized in Table 1. Whereas much scientific research is principally hypothesis led, there remains, nevertheless, an important place for exploratory research. High resolution NMR can measure, directly and simultaneously, a wide range of endogenous metabolites in biological fluids and has the unique capability of providing structural information on the metabolites detected. It has proved to be a powerful research tool with which to study inherited metabolic diseases, renal disease, drug metabolism, and toxicity, and can be used to monitor the effects of drug therapy. For instance, by using a library of experimental toxins one can map the metabolic profile of site-specific nephron injury. With this approach in man one could eventually take an unknown disease such as Balkan nephropathy and predict the initial site of tubular injury, the mode of injury and therefore the kind of toxin capable of producing that injury. NMR spectroscopic techniques are still advancing rapidly, with ever increasing sensitivity and sophistication of NMR pulse sequences to enhance structural elucidation in complex mixtures. Given the advances in directly coupled HPLC-NMR and even HPLC-NMR-mass spectroscopy it is likely that these technologies in conjunction with pattern recognition will make major contribution to our understanding of renal processes and provide new diagnostic insights in the 21st century.      

Persistence of systemic mastocytosis after allogeneic bone marrow transplantation in spite of complete remission of the associated myelodysplastic syndrome.

A myelodysplastic syndrome (MDS), type 5 (RAEB-t), and systemic mastocytosis affecting the spleen, the splenic lymph nodes, the bone marrow and the liver were diagnosed in a 38-year-old woman. The clinical course was complicated by splenic vein thromboses and iliac artery embolism. The thrombotic episodes might be secondary to mast cell mediator release. A complete remission of the MDS was obtained by allogeneic bone marrow transplantation, but the mastocytosis persisted. Thus, the possibility that the mast cell originates from a common myeloid precursor cell may be questioned.     

SARS CTL Vaccine Candidates — HLA Supertype, Genome-Wide Scanning and Biochemical Validation

An effective SARS vaccine is likely to include components that can induce specific cytotoxic T-cell (CTL) responses. The specificities of such responses are governed by HLA-restricted presentation of SARS-derived peptide epitopes. Exact knowledge of how the immune system handles protein antigens would allow for the identification of such linear sequences directly from genomic/proteomic sequence information. The latter was recently established when a causative coronavirus (SARS CoV) was isolated and full-length sequenced. Here, we have combined advanced bioinformatics and high-throughput immunology to perform an HLA supertype, genome-wide scan for SARS-specific cytotoxic T cell epitopes. The scan includes all nine human HLA supertypes in total covering >99% of all major human populations. For each HLA supertype, we have selected the 15 top candidates for test in biochemical-binding assays. At this time (approximately 6 months after the genome was established), we have tested the majority of the HLA supertypes and identified almost 100 potential vaccine candidates. These should be further validated in SARS survivors and used for vaccine formulation. We suggest that immunobioinformatics may become a fast and valuable tool in rational vaccine design.     

No correlation between number of MRI-evident lesions in cerebrum and the soleus stretch reflex in multiple sclerosis patients

The aim of the study was to investigate if the stretch reflex of the soleus muscle was useful in quantifying upper motor neuron lesions. The soleus stretch reflex was recorded in 10 healthy subjects and 20 patients with active relapsing-remitting multiple sclerosis and correlated to the number of MRI lesions in cerebrum and clinical scores (expanded disability status scale and regional functional scoring system). The short latency stretch reflex was elicited by rotating the left ankle joint 4 degrees with a rise time in the interval of 40-640 ms. The amplitude of the stretch was larger in multiple sclerosis patients being 88.5 microV in patients and 12.8 microV in controls, P = 0.007. The sensitivity of the stretch reflex expressed as the slope of the best linear fit was increased in MS patients to 2.6 microVs/degree compared with 0.6 microVs/degree (0.1-2.2) in controls, P = 0.009. There was no correlation between amplitude of the stretch reflex and number of MRI lesions (r = -0.03). In conclusion, the soleus stretch reflex might be useful to quantify spasticity but is not useful in detecting dysfunction of upper motor neurons in MS.     

Evidence for an association between hairy cell leukemia and renal cell and colorectal carcinoma.

BACKGROUND. Hairy cell leukemia (HCL) has been associated with several disease states. In this study, a possible association is reported between HCL and renal cell carcinoma (RCC) and colorectal carcinoma (CRC). METHODS. A retrospective study of the case records of 50 patients with HCL in a study of alpha-interferon (alpha-IFN) treatment of HCL. RESULTS. Three of 50 patients with HCL studied had RCC, and 2 of these also had CRC. In addition, two other patients had CRC. The other malignant lesions developed either before or after the diagnosis of HCL. In all patients, the HCL responded to alpha-interferon (alpha-IFN), but in four patients, the second lesion was diagnosed during IFN treatment. CONCLUSIONS. These findings could indicate that IFN does not correct a possible common basic etiologic defect and shows that even early CRC and RCC do not respond to the IFN doses administered. These findings should be considered in future trials of IFN treatment of these diseases. The authors also recommend a reevaluation of the frequency of second malignant lesions in HCL; this may be important particularly with the increased survival in patients with HCL who receive alpha-IFN treatment.     

Excitatory amino acid agonists. Enzymic resolution, X-ray structure, and enantioselective activities of (R)- and (S)-bromohomoibotenic acid

The enantiomers of alpha-amino-4-bromo-3-hydroxy-5-isoxazolepropionic acid (4-bromohomoibotenic acid, Br-HIBO, 1) a selective and potent agonist at one class of the central (S)-glutamic acid receptors, were prepared with an enantiomeric excess higher than 98.8% via stereoselective enzymic hydrolysis of (RS)-alpha-(acetylamino)-4-bromo-3-methoxy-5-isoxazolepropionic acid (4) using immobilized aminoacylase. The absolute configuration of the enantiomers of Br-HIBO was established by X-ray crystallographic analysis, which confirmed the expected preference of the enzyme for the S form of the substrate 4. (S)- and (RS)-Br-HIBO were potent neuroexcitants on cat spinal neurones in vivo, while (R)-Br-HIBO was a very weak excitant. Correspondingly, the S enantiomer of Br-HIBO (IC50 = 0.34 microM) was considerably more potent than the R form (IC50 = 32 microM) as an inhibitor of [3H]-(RS)-alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid ([ 3H]AMPA) binding to rat brain synaptic membranes in vitro. In contrast, (S)- and (R)-Br-HIBO were approximately equipotent (IC50 values of 0.22 and 0.15 microM, respectively) as inhibitors of [3H]-(S)-glutamic acid binding in the presence of CaCl2. The enantiomers of Br-HIBO showed no significant affinity for those binding sites on rat brain membranes which are labeled by [3H]kainic acid or [3H]-(R)-aspartic acid.     

Lymphatic transport from normal and synovitic knees in rabbits

The resorption pattern of synovial fluid through the lymphatic system from normal and synovitic knee joints in rabbits was studied with ^99mHechnetium-rhenium-sulfur colloid injected intraarticularly and monitored for 14 hours with a gamma camera.

On the normal side the regional lymph nodes were visualized after I hour and after 14 hours still 75 percent activity remained in the knee. In the synovitic knees no lymphatic transport could be detected; and the radiotracer was unstable with rapid liberation of technetium, which was excreted in the urine. This radiolysis was not found in vitro in synovitic joint fluid.

The lymphatic transport from normal rabbit knees is low. We found a clear difference in lymphatic transport between normal and synovitic knee joints.