Professor Gerard Jonderko--life and achievements of the honorary member of the Polish Society of Internal Medicine

Between February 1995 to August 1997, 120 patients underwent elective stent implantation for isolated proximal left anterior descending coronary artery stenosis. Their age ranged from 31 to 72 years (mean: 50.8 +/- 10.2) and the majority (89%) were males. All patients had angina, documented myocardial ischemia or both and 70 percent or more luminal diameter stenosis in the proximal left anterior descending before the origin of any branch. Majority (62.5%) of the treated lesions were type A. Successful deployment of the stent at the target site was achieved in all patients without any major in-hospital complications, including myocardial infarction, emergency bypass graft surgery or death. Clinical follow-up, ranging from 6 to 31 months (mean: 18.5 +/- 8.1, median: 20), was available in 87 out of 92 (94.5%) eligible patients who had completed at least six months after the procedure. Freedom from angina, myocardial infarction, target lesion revascularization and death was observed in 90.8, 100, 95.4 and 97.7 percent of patients, respectively. By the Kaplan-Meier estimate, an event-free survival (absence of death, myocardial infarction, recurrence of angina or revascularization) was 95.4 percent at six months, 89.5 percent at 12 and 18 months and 82.7 percent at 24 to 31 months of follow-up. Only 10 (11.5%) patients developed any event and TLR was required in 4.6 percent of patients. In conclusion, elective stenting for isolated proximal left anterior descending stenosis can be achieved safely and successfully in all patients without any adverse in-hospital events. This modality of treatment also provides long-term benefits in terms of reduction in major cardiovascular events and need for subsequent revascularization.     

Scientific and artistic investigation of multi-dimensional fractals on the AT & T pixel machine

The pipelined architecture and parallel organization of the AT&T Pixel Machine image computer are described and demonstrated with applications for the visualization of multidimensional fractals, particularly linear fractals and quaternion/ stacked Julia sets. Techniques for pushing the Pixel Machine to its peak abilities are described and apply to more recent parallel image computers as well.     

Chronic fluoride exposure does not cause detrimental, extraskeletal effects in nutritionally deficient rats

On the basis of observations that endemic fluorosis occurs more often in malnourished populations, a series of studies tested the hypothesis that deficient dietary intake of calcium, protein or energy affects fluoride metabolism so that the margin of safe fluoride exposure may be reduced. The objective of the investigation was to determine whether changes in fluoride metabolism in nutritionally deficient rats resulted in manifestation of any extraskeletal toxic fluoride effects not observed in healthy animals. This investigation included two studies, one that monitored the effect of calcium deficiency on the effects of chronic fluoride exposure, and a second study that observed fluoride effects in rats that were deficient either in protein or in energy and total nutrient intake. Control and experimental rats received drinking water containing 0, 0.26 (5), 0.79 (15) or 2.63 (50) mmol fluoride/L (mg/L) for 16 or 48 wk. Control rats were fed optimal diets and experimental rats were fed diets deficient in calcium (Study 1) or protein (Study 2). An additional group of experimental rats (Study 2) was provided with a restricted amount of diet; thus these rats were deficient in energy and total nutrient intake. The intake, excretion and retention of fluoride were monitored; after the rats were killed, tissue fluoride levels and biochemical markers of tissue function were analyzed. Bone marrow cells were harvested from some of the rats, after 48 wk of treatment, for determining the frequency of sister chromatid exchange, a marker of genetic damage. Although there were significant differences among fluoride treatment groups in fluoride excretion and retention that resulted in significantly greater fluoride levels in tissues of the experimental rats, we were unable to detect any harmful, extraskeletal biochemical, physiologic or genetic effects of fluoride in the nutritionally deficient rats.     

An outbreak of Salmonella mikawasima associated with doner kebabs

During October 1992 an increase in the number of isolates of Salmonella mikawasima, a rare serotype, was noted including a cluster of nine cases in the South West Thames region. A case control study was conducted and univariate analysis showed a statistical association between illness and eating at take-away A for cases compared with household controls (P = 0.003) and with neighbourhood controls (P = 0.0245). Cases were also more likely to have eaten kebabs than were controls or average take-away A customers, implicating doner kebabs as the most likely vehicle of infection. Plasmid profile analysis of the nine cases' isolates showed them to be indistinguishable and to be characterized by a single plasmid of approximately 60 MDa. The original source of the Salmonella mikawasima contamination was not determined, but food preparation practices for kebabs at take-away A were insufficient to protect against illness if contaminated. This outbreak was only recognized because of the unusual serotype, but could be an indication of a more widespread problem with doner kebabs.     

Selective employment of chemokine receptors as human immunodeficiency virus type 1 coreceptors determined by individual amino acids within the envelope V3 loop

The chemokine receptor CCR5 acts as an essential cofactor for cell entry by macrophage-tropic human immunodeficiency virus type 1 (HIV-1) strains, whereas CXCR4 acts as an essential cofactor for T-cell-line-adapted strains. We demonstrated that the specific amino acids in the V3 loop of the HIV-1 envelope protein that determine cellular tropism also regulate chemokine coreceptor preference for cell entry by the virus. Further, a strong correlation was found between HIV-1 strains classified as syncytium inducing in standard assays and those using CXCR4 as a coreceptor. These data support the hypothesis that progressive adaptation to additional coreceptors is a key molecular basis for HIV-1 phenotypic evolution in vivo.     

Presence of enamel on the incisors of the llama (Lama glama) and alpaca (Lama pacos)

Cytoplasmic aggregation is an early resistance-associated event that is observed in potato tissues either after penetration of an incompatible race of Phytophthora infestans, the potato late blight fungus, or after treatment with hyphal wall components (HWC) prepared from P. infestans. In potato cells in suspension culture, the number of cells with cytoplasmic aggregation increased upon treatment with HWC, but such an increase was suppressed by treatment with cytochalasin D prior to treatment with HWC. This result suggested that cytoplasmic aggregation in cultured potato cells might be connected with the association of actin filaments. To identify the molecular basis of cytoplasmic aggregation, we purified actin and actin-related proteins by affinity chromatography on a column of immobilized DNase I from cultured potato cells and isolated proteins of 43 kDa, 32 kDa and 22 kDa. Analysis of the amino-terminal amino acid sequences indicated that the 43 kDa, 32 kDa and 22 kDa proteins were potato actin, basic chitinase and osmotin-like protein, respectively. This conclusion was supported by the results of Western blotting analysis of the 43 kDa and 32 kDa proteins with antibodies against actin and basic chitinase. Binding analysis with actin coupled to actin-specific antibodies and biotinylated actin suggested that the 32 kDa and 22 kDa proteins had actin-binding activity. In addition, examination of biomolecular interactions using an optical biosensor confirmed the binding of chitinase to actin. These results imply the possibility that basic chitinase and osmotin-like protein might be involved in cytoplasmic aggregation, hereby participating. In the potato cell's defense against attack by pathogen.     

Assessment of cocaine use with quantitative urinalysis and estimation of new uses

Qualitative urinalysis methods of monitoring cocaine use may over-detect frequency of use, possibly decreasing the ability of clinical trials to detect effective treatments. Quantitative urinalysis and newly developed criteria for identifying new cocaine use were evaluated as alternative measures of cocaine use. Urine specimens collected in a cocaine dosing study in non-treatment-seeking subjects (n = 5) and a cocaine treatment trial (n = 37) were analyzed for the cocaine metabolite, benzoylecgonine, with qualitative and quantitative methods. Pharmacokinetic criteria ('New Use' rules) were applied to quantitative data to identify occasions of new cocaine use. Results were compared to known cocaine administrations in the laboratory study and to self-reported drug use and qualitative urinalysis for subjects in the clinical trial. New Use criteria correctly identified cocaine administrations in the cocaine dosing study in all but a small number of specimens. In the clinical trial, quantitative urinalysis and estimated New Uses provided more information about patterns and frequency of use than qualitative urinalysis in the different treatment conditions in the clinical trial. Interpretation of quantitative urinalysis with New Use rules appears to be a useful method for monitoring treatment outcome and may be more accurate than traditional qualitative urinalysis in estimating frequency of cocaine use.     

Dantrolene inhibition of sarcoplasmic reticulum Ca2+ release by direct and specific action at skeletal muscle ryanodine receptors

The skeletal muscle relaxant dantrolene inhibits the release of Ca2+ from the sarcoplasmic reticulum during excitation-contraction coupling and suppresses the uncontrolled Ca2+ release that underlies the skeletal muscle pharmacogenetic disorder malignant hyperthermia; however, the molecular mechanism by which dantrolene selectively affects skeletal muscle Ca2+ regulation remains to be defined. Here we provide evidence of a high-affinity, monophasic inhibition by dantrolene of ryanodine receptor Ca2+ channel function in isolated sarcoplasmic reticulum vesicles prepared from malignant hyperthermia-susceptible and normal pig skeletal muscle. In media simulating resting myoplasm, dantrolene increased the half-time for 45Ca2+ release from both malignant hyperthermia and normal vesicles approximately 3.5-fold and inhibited sarcoplasmic reticulum vesicle [3H]ryanodine binding (Ki approximately 150 nM for both malignant hyperthermia and normal). Inhibition of vesicle [3H]ryanodine binding by dantrolene was associated with a decrease in the extent of activation by both calmodulin and Ca2+. Dantrolene also inhibited [3H]ryanodine binding to purified skeletal muscle ryanodine receptor protein reconstituted into liposomes. In contrast, cardiac sarcoplasmic reticulum vesicle 45Ca2+ release and [3H]ryanodine binding were unaffected by dantrolene. Together, these results demonstrate selective effects of dantrolene on skeletal muscle ryanodine receptors that are consistent with the actions of dantrolene in vivo and suggest a mechanism of action in which dantrolene may act directly at the skeletal muscle ryanodine receptor complex to limit its activation by calmodulin and Ca2+. The potential implications of these results for understanding how dantrolene and malignant hyperthermia mutations may affect the voltage-dependent activation of Ca2+ release in intact skeletal muscle are discussed.     

Molecular cloning of CYP1A from the estuarine fish Fundulus heteroclitus and phylogenetic analysis of CYP1 genes: update with new sequences

Since we published a phylogenetic analysis of the CYP1A subfamily in 1995, several additional full-length sequences have been reported, including three members of an entirely new subfamily, CYP1B. Two avian sequences were recently published, so that CYP1A sequence data are now available from three of the five major vertebrate lineages. The two new branches that have been added to the CYP1 family tree significantly add to our understanding of P450 evolution. The inclusion of the CYP1Bs to the phylogenetic analysis allows us to root inferred trees. Addition of the avian CYP1As indicates that the CYP1A1/CYP1A2 duplication present in the mammalian lineage may have occurred after the divergence of birds and mammals. The number of fish species from which full-length coding regions of CYP1A genes have been sequenced has increased from four (trout, plaice, toadfish, and scup) to nine. These include CYP1A sequences from tomcod, butterflyfish, sea bream, sea bass, and the full-length sequence of CYP1A from the killifish Fundulus heteroclitus that is reported here. Phylogenetic analyses incorporating the new fish CYP1A sequences support our original conclusion that the fish CYP1As are monophyletic and indicate that the genes are evolving at very different rates in different species.     

Incremental iron overload during reperfusion progressively augments oxidative injury

OBJECTIVE: To determine if a relationship exists between the extent of iron-catalyzed injury and the degree of tissue iron overload during reperfusion. METHODS: To selectively increase tissue iron only during early reperfusion, isolated, buffer perfused rabbit hearts were exposed to 20 microM Fe(2+)-100 microM ADP during the last 3 minutes of ischemia and the initial 4 minutes of reperfusion. Control groups were exposed to ADP and iron-ADP regimens that did not increase intracellular iron. All the hearts received 30 minutes of normothermic global ischemia and 30 minutes of reperfusion. Heart function was monitored continuously throughout each experiment. Tissue iron and biochemical markers were analyzed at the end of experiments. RESULTS: Hemodynamic recovery was decreased and tissue lipid peroxide levels were increased in the 20 microM Fe(2+)-100 microM ADP group compared to controls. The recoveries of developed pressure and positive/negative dP/dT at 30 minutes of reperfusion were negatively correlated with tissue iron levels, while cytosol and membrane lipid peroxide levels correlated positively with the iron levels during reperfusion. CONCLUSION: The extent of oxidative injury during reperfusion was directly related to the tissue iron burden present during reperfusion. Increased lipid peroxidation was the principal chemical marker of iron-catalyzed injury.