Tobramycin and gentamycin elution analysis between two in situ polymerizable orthopedic composites

This research analyzed Tobramycin and Gentamycin elution characteristics for two antibiotic-impregnated bone composites: PMMA-based Simplex P and the novel, hybrid, bioactive, CORTOSS. Experimental results were correlated with composite hydrophilicity and antibiotic phase partitioning behaviors. The phase partitioning experiment was conducted to understand antibiotic solubility in aqueous environments. By comparing experimental results with calculated data, antibiotic release behavior was predicted. Total Tobramycin elution percentages from CORTOSS and Simplex P were 12.5 and 6.4%, respectively. Total Gentamycin elution percentages from CORTOSS and Simplex P were 6.95 and 10.17%, respectively. Phase partitioning data indicate 100% of Tobramycin remains in aqueous phases, being extremely hydrophilic. This is supported by its calculated theoretical value (log P = - 7.32). Results suggest that Tobramycin elution can be attributed to composite hydrophilicity as well as its high degree of hydrophilicity. Fifteen percent of Gentamycin distributes in hydrophobic phases (log P = - 4.22). Despite a lower Gentamycin hydrophilicity, its release was affected by its complexation with polar salts in the leaching buffer, thereby increasing its elution potential, making it appreciably water soluble. CORTOSS is more hydrophilic; therefore the migration of aqueous liquids into the polymer network of CORTOSS facilitates greater antibiotic elution compared with hydrophobic Simplex P.

Transcription factor 1 and beta-cell function in glucose-tolerant subjects

AIMS

Although beta-cell dysfunction and insulin resistance are observed in patients with Type 2 diabetes, beta-cell dysfunction plays a crucial role in the development of the disease. Mutations of transcription factor 1 (TCF1, or hepatocyte nuclear factor-1alpha) affect beta-cell function. We examined the impact of amino acid polymorphisms of this gene on beta-cell function in 60 glucose-tolerant Caucasians.

METHODS

Insulin sensitivity index (ISI) and 1st and 2nd phase insulin responses (1stIR, 2ndIR) were measured using the hyperglycaemic clamp. The genotypes were determined from genomic DNA and their impact on beta-cell function was investigated.

RESULTS

Among three polymorphisms (I27L, A98V, and S487N), significant impact on beta-cell function was found in the I27L polymorphism. Univariate analyses revealed differences for the I27L polymorphism in both 1stIR (P = 0.0052) and 2ndIR (P = 0.0432). Multivariate analysis revealed that the I27L polymorphism (P = 0.0124) with ISI accounted for 32% of the variation in 1stIR and had a marginal impact on 2ndIR (P = 0.0343), accounting for 52% of the variation with ISI and age. By dissecting out the impact of other covariate(s), the I27L polymorphism independently explained 12% of the variation in 1stIR and 6% of the variation in 2ndIR.

CONCLUSION

The I27L polymorphism of TCF1 is an independent determinant of beta-cell function by affecting both 1st and 2nd phase insulin response. This polymorphism could play a role in the pathogenesis of Type 2 diabetes. A large-scale association study (approx. 2000 subjects) will be required to demonstrate the genetic susceptibility of this polymorphism to Type 2 diabetes.

Genome-wide multipoint linkage analyses of multiplex schizophrenia pedigrees from the oceanic nation of Palau

The oceanic nation of Palau has been geographically and culturally isolated over most of its 2000 year history. As part of a study of the genetic basis of schizophrenia in Palau, we genotyped five large, multigenerational schizophrenia pedigrees using markers every 10 cM (CHLC/Weber screening set 6). The number of affected/unaffected individuals genotyped per family ranged from 11/21 to 5/5. Thus the pedigrees varied in their information for linkage, but each was capable of producing a substantial LOD score. We fitted a simple dominant and recessive model to these data using multipoint linkage analysis implemented by Simwalk2. Predictably, the most informative pedigrees produced the best linkage results. After genotyping additional markers in the region, one pedigree produced a LOD = 3.4 (5q distal) under the dominant model. Seven of nine schizophrenics in the pedigree, mostly 3rd-4th degree relatives, share a 15-cM, 7-marker haplotype. For a different pedigree, another promising signal occurred on distal 3q, LOD = 2.6, for the recessive model. For two other pedigrees, the best LODs were modest, slightly better than 2.0 on 5q and 9p, while the fifth pedigree produced no noteworthy linkage signal. Similar to the results for other populations, our results suggest there are multiple genes conferring liability to schizophrenia even in the small population of Palau (roughly 21,000 individuals) in remote Oceania.

Measurement in vivo of proliferation rates of slow turnover cells by 2H2O labeling of the deoxyribose moiety of DNA

We describe here a method for measuring DNA replication and, thus, cell proliferation in slow turnover cells that is suitable for use in humans. The technique is based on the incorporation of (2)H(2)O into the deoxyribose (dR) moiety of purine deoxyribonucleotides in dividing cells. For initial validation, rodents were administered 4% (2)H(2)O in drinking water. The proliferation rate of mammary epithelial cells in mice was 2.9% per day and increased 5-fold during pregnancy. Administration of estradiol pellets (0-200 microg) to ovariectomized rats increased mammary epithelial cell proliferation, according to a dose-response relationship up to the 100 microg dose. Similarly, proliferation of colon epithelial cells was stimulated in a dose-response manner by dietary cholic acid in rats. Bromodeoxyuridine labeling correlated with the (2)H(2)O results. Proliferation of slow turnover cells was then measured. Vascular smooth muscle cells isolated from mouse aorta divided with a half-life in the range of 270-400 days and die-away values after (2)H(2)O wash-out confirmed these slow turnover rates. The proliferation rate of an adipocyte-enriched fraction from mouse adipose tissue depots was 1-1.5% new cells per day, whereas obese ad libitum-fed obob mice exhibited markedly higher fractional and absolute proliferation rates. In humans, stable long-term (2)H(2)O enrichments in body water were achieved by daily (2)H(2)O intake, without toxicities. Labeled dR from fully turned-over blood cells (monocytes or granulocytes) exhibited a consistent amplification factor relative to body (2)H(2)O enrichment ( approximately 3.5-fold). The fraction of newly divided naive-phenotype T cells after 9 weeks of labeling with (2)H(2)O was 0.056 (CD4(+)) and 0.043 (CD8(+)) (replacement rate <0.1% per day). In summary, (2)H(2)O labeling of dR in DNA allows safe, convenient, reproducible, and inexpensive measurement of cell proliferation in humans and experimental animals and is well suited for slow turnover cells.

Bacterial water quality in the personal water bottles of elementary students

BACKGROUND

Samples of drinking water were collected directly from the personal water bottles of students at an elementary school in Calgary, Alberta.

METHODS

Total and fecal coliforms and heterotrophic bacteria were enumerated using membrane filtration and agar plate count methods respectively.

RESULTS

The Canadian Drinking Water Quality Guidelines (CWQG) criterion was exceeded for total coliform in 13.3% of 75 samples. Fecal coliform and total heterotrophic criteria were exceeded in 8.9% (of 68 samples) and 64.4% (of 76 samples) respectively.

FINDINGS

The use of personal water bottles for students in elementary classrooms is not recommended.

Bacterial water quality in the personal water bottles of elementary students

BACKGROUND

Samples of drinking water were collected directly from the personal water bottles of students at an elementary school in Calgary, Alberta.

METHODS

Total and fecal coliforms and heterotrophic bacteria were enumerated using membrane filtration and agar plate count methods respectively.

RESULTS

The Canadian Drinking Water Quality Guidelines (CWQG) criterion was exceeded for total coliform in 13.3% of 75 samples. Fecal coliform and total heterotrophic criteria were exceeded in 8.9% (of 68 samples) and 64.4% (of 76 samples) respectively.

FINDINGS

The use of personal water bottles for students in elementary classrooms is not recommended.

Corticosterone exerts site-specific and state-dependent effects in prefrontal cortex and amygdala on regulation of adrenocorticotropic hormone, insulin and fat depots

Chronic stress stimulates corticosterone secretion and recruits brain pathways that regulate energy balance (caloric acquisition and deposition) and facilitate hypothalamic-pituitary-adrenal responsiveness to new stressors. We implanted corticosterone or cholesterol bilaterally either near the central nucleus of the amygdala (CeA) or in the prefrontal cortex to determine whether high concentrations of the steroid act at either site, with or without chronic stress. Rats were adrenalectomized and treated systemically with low doses of corticosterone. Half were maintained at room temperature and the other half were exposed to 5 degrees C cold for 5 days before all rats were restrained. There was limited diffusion of corticosterone from brain implants. Corticosterone in prefrontal cortex, but not CeA, decreased plasma insulin and adrenocorticotropic hormone (ACTH) responses to acute restraint in both control and chronically cold stressed rats. Corticosterone implants near CeA decreased the weight of fat depots only in cold; corticosterone implants in prefrontal cortex were ineffective. We conclude that (i) corticosterone inhibits insulin and ACTH secretion by an action in prefrontal cortex but not CeA; (ii) high concentrations of corticosterone secreted during chronic stress alter metabolism through (autonomic) outputs of the CeA and prefrontal cortex in site- and variable-specific fashion; and (iii) the amygdala is a component of a stress-recruited, state-dependent pathway.

Fatty acid binding protein 2 and insulin resistance

BACKGROUND

An A54T polymorphism of the fatty acid binding protein 2 (FABP2) gene was found to be associated with insulin resistance in nondiabetic Pima Indians. Design This is a cross-sectional study to examine the role of this polymorphism in insulin resistance in 71 healthy and normotensive Caucasian subjects with normal glucose tolerance. Insulin sensitivity (%S, ISI(M), ISI(S)) and beta-cell function (%B, dI/dG, 1stPHS, 2ndPHS) were estimated based on published models. Their genotypes were determined using a polymerase chain reaction-restriction fragment length polymorphism assay. The relationship between genotypes and phenotypes was examined.

RESULTS

After genotyping, we identified 34 AA, 32 AT and five TT subjects. The TT subjects were pooled together with the AT subjects during the analysis due to their low number. No difference was noted in gender distribution, clinical features, or fasting lipid profile between the two genotypic groups (AA vs. AT/TT). The AT/TT group had lower %S and ISI(S) than the AA group (P = 0.0118 and P = 0.0170, respectively). The difference in ISI(M) was marginal (P = 0.0544). However, no difference was noted in beta-cell function between the two groups. Multivariate analysis revealed that this polymorphism was an independent but modest determinant for %S (P = 0.0149), ISI(M) (P = 0.0489) and ISI(S) (P = 0.0175). It independently contributed 6.04% (95% CI, 0.02-20.53%), 4.28% (95% CI, 0.08-17.63%) and 4.94% (95% CI, 0.01-18.75%) of the variation of %S, ISI(M) and ISI(S), respectively.

CONCLUSIONS

We demonstrated that the A54T polymorphism at the FABP2 locus is a risk factor for insulin resistance in a Caucasian population.

Mycotic aneurysm and cerebral infarction resulting from fungal sinusitis: imaging and pathologic correlation

SUMMARY

A 73-year-old man was admitted with invasive aspergillus of the sphenoid sinus. Endoscopic debridement of the sphenoid sinus was complicated by rupture of a mycotic cavernous carotid artery aneurysm with severe epistaxis. The aneurysm was closed emergently by endovascular coil placement. Subsequently, the mycotic aneurysm extended intradurally and caused fatal subarachnoid hemorrhage. The radiologic-pathologic data illustrate the mechanism of fungal mycotic aneurysm formation and growth. This case emphasizes the need for rapid diagnosis of potential fungal involvement of the central nervous system and suggests the necessity for aggressive treatment once fungal cerebrovascular involvement is identified.

A high-resolution radiation hybrid map of the human genome draft sequence

We have constructed a physical map of the human genome by using a panel of 90 whole-genome radiation hybrids (the TNG panel) in conjunction with 40,322 sequence-tagged sites (STSs) derived from random genomic sequences as well as expressed sequences. Of 36,678 STSs on the TNG radiation hybrid map, only 3604 (9.8%) were absent from the unassembled draft sequence of the human genome. Of 20,030 STSs ordered on the TNG map as well as the assembled human genome draft sequence and the Celera assembled human genome sequence, 36% of the STSs had a discrepant order between the working draft sequence and the Celera sequence. The TNG map order was identical to one of the two sequence orders in 60% of these discrepant cases.

Defining the atherogenicity of large and small lipoproteins containing apolipoprotein B100

Apo-E-deficient apo-B100-only mice (APOE:(-/-)APOB:(100/100)) and LDL receptor-deficient apo-B100-only mice (LDLR:(-/-)APOB:(100/100)) have similar total plasma cholesterol levels, but nearly all of the plasma cholesterol in the former animals is packaged in VLDL particles, whereas, in the latter, plasma cholesterol is found in smaller LDL particles. We compared the apo-B100-containing lipoprotein populations in these mice to determine their relation to susceptibility to atherosclerosis. The median size of the apo-B100-containing lipoprotein particles in APOE:(-/-)APOB:(100/100) plasma was 53.4 nm versus only 22.1 nm in LDLR:(-/-)APOB:(100/100) plasma. The plasma levels of apo-B100 were three- to fourfold higher in LDLR:(-/-)APOB:(100/100) mice than in APOE:(-/-)APOB:(100/100) mice. After 40 weeks on a chow diet, the LDLR:(-/-)APOB:(100/100) mice had more extensive atherosclerotic lesions than APOE:(-/-)APOB:(100/100) mice. The aortic DNA synthesis rate and the aortic free and esterified cholesterol contents were also higher in the LDLR:(-/-)APOB:(100/100) mice. These findings challenge the notion that all non-HDL lipoproteins are equally atherogenic and suggest that at a given cholesterol level, large numbers of small apo-B100-containing lipoproteins are more atherogenic than lower numbers of large apo-B100-containing lipoproteins.

A cholecystokinin-mediated pathway to the paraventricular thalamus is recruited in chronically stressed rats and regulates hypothalamic-pituitary-adrenal function

Chronic stress alters hypothalamic-pituitary-adrenal (HPA) responses to acute, novel stress. After acute restraint, the posterior division of the paraventricular thalamic nucleus (pPVTh) exhibits increased numbers of Fos-expressing neurons in chronically cold-stressed rats compared with stress-naive controls. Furthermore, lesions of the PVTh augment HPA activity in response to novel restraint only in previously stressed rats, suggesting that the PVTh is inhibitory to HPA activity but that inhibition occurs only in chronically stressed rats. In this study, we further examined pPVTh functions in chronically stressed rats. We identified afferent projections to the pPVTh using injection of the retrograde tracer fluorogold. Of the sites containing fluorogold-labeled cells, neurons in the lateral parabrachial, periaqueductal gray, and dorsal raphe containing fluorogold also expressed cholecystokinin (CCK) mRNA. We then examined whether these CCKergic inputs to the pPVTh were involved in HPA responses to acute, novel restraint after chronic stress. We injected the CCK-B receptor antagonist PD 135,158 into the PVTh before restraint in control and chronically cold-stressed rats. ACTH responses to restraint stress were augmented by PD 135,158 only in chronically stressed rats but not in controls. In addition, CCK-B receptor mRNA expression in the pPVTh was not altered by chronic cold stress. We conclude that previous chronic stress specifically facilitates the release of CCK into the pPVTh in response to acute, novel stress. The CCK is probably secreted from neurons in the lateral parabrachial, the periaqueductal gray, and/or the dorsal raphe nuclei. Acting via CCK-B receptors in pPVTh, CCK then constrains facilitated ACTH responses to novel stress in chronically stressed but not naive rats. These results demonstrate clearly that chronic stress recruits a new set of pathways that modulate HPA responsiveness to a novel stress.

Fish oil modulates macrophage P44/P42 mitogen-activated protein kinase activity induced by lipopolysaccharide

BACKGROUND

Mitogen-activated protein kinase (MAPK) cascades represent a major signal system to transduce extracellular signals into cellular responses. Overactivity of MAPK has been implicated in the development of many diseases, including cancer and sepsis. This study investigated the hypothesis that fish oil altered the membrane phospholipid composition and modulated MAPK activity.

METHODS

RAW 264.7 cells, a mouse macrophage (Mphi) cell line, were grown in eicosapentaenoic acid (EPA)-rich media (114 micromol/L) for 48 hours. Mphi were washed and exposed to Escherichia coli lipopolysaccharide (LPS; 1 microg/mL) for 10 minutes. Both total and activated (phosphorylated) portions of MAPK (P44 and P42) were determined by Western blot assays. AP-1 transcription factor activity was determined by electrophoretic mobility gel shift assays (EMSA). Mphi tumor necrosis factor (TNF) mRNA expression was measured by Northern blot assays.

RESULTS

LPS stimulation induced RAW cell phosphorylation of P44/P42. In contrast, RAW cells grown in EPA-rich media had less P44/P42 activation in the presence of LPS. Total P44/P42 were not affected by EPA or LPS. Similarly, EPA also inhibited AP-1 activity. Inhibition of P44/P42 activity with PD98059 reduced both AP-1 activity and TNF mRNA expression of LPS-stimulated Mphi.

CONCLUSIONS

Our data suggest that fish oil regulates macrophage proinflammatory gene activation, at least in part, by modulating the MAPK activity.

Phototherapy with blue (415 nm) and red (660 nm) light in the treatment of acne vulgaris

In this study we have evaluated the use of blue light (peak at 415 nm) and a mixed blue and red light (peaks at 415 and 660 nm) in the treatment of acne vulgaris. One hundred and seven patients with mild to moderate acne vulgaris were randomized into four treatment groups: blue light, mixed blue and red light, cool white light and 5% benzoyl peroxide cream. Subjects in the phototherapy groups used portable light sources and irradiation was carried out daily for 15 min. Comparative assessment between the three light sources was made in an observer-blinded fashion, but this could not be achieved for the use of benzoyl peroxide. Assessments were performed every 4 weeks. After 12 weeks of active treatment a mean improvement of 76% (95% confidence interval 66-87) in inflammatory lesions was achieved by the combined blue-red light phototherapy; this was significantly superior to that achieved by blue light (at weeks 4 and 8 but not week 12), benzoyl peroxide (at weeks 8 and 12) or white light (at each assessment). The final mean improvement in comedones by using blue-red light was 58% (95% confidence interval 45-71), again better than that achieved by the other active treatments used, although the differences did not reach significant levels. We have found that phototherapy with mixed blue-red light, probably by combining antibacterial and anti-inflammatory action, is an effective means of treating acne vulgaris of mild to moderate severity, with no significant short-term adverse effects.

Tissue specificity of E- and P-selectin ligands in Th1-mediated chronic inflammation

The demonstrated role of E- and P-selectin ligands in the recruitment of Th1 cells raises the question of tissue specificity determination by pathogenic T cells. We took advantage of the fact that chronic Th1-mediated inflammation in the scid/scid CD4+CD45RBhigh T cell transfer model can occur at multiple tissue sites, resembling inflammatory bowel disease in the colon and psoriasis in the skin. We show that the majority of infiltrating effector T cells from psoriatic skin expresses high levels of functional P-selectin ligand (87 +/- 3%), detected by P-selectin-Ig (PIg), while a significantly smaller subset of T cells from colitic lesions expresses this ligand (24 +/- 2%). Similarly, E-selectin ligand is preferentially expressed on CD4+ T cells infiltrating the skin (24 +/- 2%), but only on very few CD4+ T cells infiltrating the colon (CIT; 1.3 +/- 0.8%). In contrast, CD4+ T cells infiltrating the skin express alpha4beta7 at a significantly lower level than CIT (mean fluorescence intensity, 28 vs 61, respectively), although, interestingly, alphaEbeta7 was expressed at high levels on both populations. Analysis of the disease-inducing potential of PIg+ and PIg- CD4+ CIT cells revealed that both populations not only express similar levels of the gut-homing molecule alpha4beta7 (mean fluorescence intensity, 50 vs 56, respectively), but do not differ in their capacity to express IFN-gamma. Furthermore, CIT depleted of cells expressing functional P-selectin ligand were able to induce colitis upon transfer, suggesting that induction of colitis in this model may be independent of E- and P-selectin. These results indicate that adhesion molecule expression and the homing pattern of inflammatory T cells are regulated by the local environment independently of their inflammatory capacity.

Warning! Nearby construction can profoundly affect your experiments

This is meant to alert people to potentially major effects of construction projects on research results. Because we study the effects of stress on regulation of ACTH and corticosterone secretion and of serotonin receptors and stress on energy balance, we serve as an early warning system when things go awry. Most of our experiments include taking daily, or twice daily, measurements of rat or mouse weights and food intake as well as stress hormone levels. We are highly sensitized to environmental disruption and we've shown previously the effects of construction on stress hormones (1). However, we did not anticipate the change and disruption in energy balance that may occur in response to environmental perturbation. We provide two examples of these, below.

Starvation: early signals, sensors, and sequelae

To identify the sequences of changes in putative signals, reception of these and responses to starvation, we sampled fed and starved rats at 2- to 6-h intervals after removal of food 2 h before dark. Metabolites, hormones, hypothalamic neuropeptide expression, fat depots, and leptin expression were measured. At 2 h, insulin decreased, and FFA and corticosterone (B) increased; by 4 h, leptin and glucose levels decreased. Neuropeptide Y messenger RNA (mRNA) increased 6 h after food removal and thereafter. Adrenal and plasma B did not follow ACTH and were elevated throughout, with a nadir at the dark-light transition. Leptin correlated inversely with adrenal B. Fat stores decreased during the last 12 h. Leptin mRNA in perirenal and sc fat peaked during the dark period, resembling plasma leptin in fed rats. We conclude that 1) within the first 4 h, hormonal and metabolic signals relay starvation-induced information to the hypothalamus; 2) hypothalamic neuropeptide synthesis responds rapidly to the altered metabolic signals; 3) catabolic activity quickly predominates, reinforced by elevated B, not driven by ACTH, but possibly to a minor extent by leptin, and more by adrenal neural activity; and 4) leptin secretion decreases before leptin mRNA or fat depot weight, showing synthesis-independent regulation.

Independent and overlapping effects of corticosterone and testosterone on corticotropin-releasing hormone and arginine vasopressin mRNA expression in the paraventricular nucleus of the hypothalamus and stress-induced adrenocorticotropic hormone release

Adrenocorticotropin (ACTH) release is regulated by both glucocorticoids and androgens; however, the precise interactions are unclear. We have controlled circulating corticosterone (B) and testosterone (T) by adrenalectomy (ADX) +/- B replacement and gonadectomy (GDX) +/- T replacement, comparing these to sham-operated groups. We hoped to reveal how and where these neuroendocrine systems interact to affect resting and stress-induced ACTH secretion. ADX responses. In gonadal-intact rats, ADX increased corticotropin-releasing factor (CRH) and vasopressin (AVP) mRNA in hypothalamic parvocellular paraventricular nuclei (PVN) and ACTH in pituitary and plasma. B restored these toward normal. GDX blocked the increase in AVP but not CRH mRNA and reduced plasma, but not pituitary ACTH in ADX rats. GDX+T restored increased AVP mRNA in ADX rats, although plasma ACTH remained decreased. Stress responses. Restraint-induced ACTH responses were elevated in ADX gonadally intact rats, and B reduced these toward normal. GDX in adrenal-intact and ADX+B rats increased ACTH responses. Without B, T did not affect ACTH; together with B, T restored ACTH responses to normal. The magnitude of ACTH responses to stress was paralleled by similar effects on the number of c-fos staining neurons in the hypophysiotropic PVN. We conclude that gonadal regulation of ACTH responses to ADX is determined by T dependent effects on AVP biosynthesis, whereas CRH biosynthesis is B-dependent. Stress-induced ACTH release is not explained by B and T interactions at the PVN, but is determined by B- and T-dependent changes in drive to PVN motorneurons.

IL-12, independently of IFN-gamma, plays a crucial role in the pathogenesis of a murine psoriasis-like skin disorder

The onset of acute psoriasis and the exacerbation of chronic psoriasis are often associated with a history of bacterial infection. We demonstrate that while only few scid/scid mice develop disease when CD4+CD45Rbhigh T cells are transferred alone, coadministration of LPS plus IL-12 or staphylococcal enterotoxin B into scid/scid mice 1 day after CD4+CD45Rbhigh T cell transfer greatly enhances disease penetrance and severity. Most importantly, the skin lesions induced by this method exhibit many of the histologic hallmarks observed in human psoriasis. Skin infiltrating CD4+ T cells were predominantly memory/effector cells (CD45Rblow) and exhibited a highly polarized Th1 phenotype. To test whether the development of pathogenic T cells was dependent on their production of IFN-gamma, we transferred IFN-gamma-/- CD4+CD45Rbhigh T cells into scid/scid or into T, B and NK cell-deficient scid/beige mice. Surprisingly, the incidence of psoriasis was similar to scid/scid animals that received IFN-gamma+/+ T cells, although acanthosis of the skin was attenuated. In contrast, the development of psoriasis was abolished if anti-IL-12 mAb was administered on day 7 and 35 after T cell transfer. Skin-derived IFN-gamma-/- inflammatory cells, but not cells from anti-IL-12-treated animals, secreted substantial amounts of TNF-alpha, suggesting that the inflammatory effect of IFN-gamma-/- T cells may be partly exerted by TNF-alpha and that the therapeutic effect of anti-IL-12 may depend on its ability to down-regulate both TNF-alpha and IFN-gamma. Overall, these results suggest that IL-12, independently of IFN-gamma, is able to induce pathogenic, inflammatory T cells that are able to induce psoriasiform lesions in mice.

Quantitative MR imaging of carpal tunnel syndrome

OBJECTIVE

Previous MR imaging studies have produced evidence of changes to structures within the wrist believed to be associated with carpal tunnel syndrome. In an attempt to resolve the conflicting and inconclusive results of these studies, we report here the results of an MR imaging study at a field strength of 3.0 T, which is higher than that previously reported.

SUBJECTS AND METHODS

Patients with carpal tunnel syndrome and control groups of asymptomatic subjects were studied using MR imaging. We evaluated electrophysiologically the median nerve function of the affected wrists of all patients. A gradient-recalled echo pulse sequence was used to study 13 3-mm-thick slices within the wrist of each patient or asymptomatic subject. Spatial resolution was approximately 0.3 x 0.3 mm2. The median nerve and other structures associated with the carpal tunnel, which were clearly shown on the MR images, were analyzed to yield structural data.

RESULTS

Analysis revealed that the cross-sectional area of the nerve within and proximal to the carpal tunnel was approximately 50% larger in patients with carpal tunnel syndrome than in asymptomatic subjects. We found no significant difference in the area of the nerve within the carpal tunnel compartment compared with the area of the nerve proximal to the carpal tunnel either in patients or in asymptomatic subjects. Also, flattening of the nerve on entering the carpal tunnel was not significantly different in patients than in asymptomatic subjects. In patients an increase in the palmar bowing of the flexor retinaculum was found only at the level of the hamate compared with that found in asymptomatic subjects. The cross-sectional area of the carpal tunnel was of a similar size in patients and in asymptomatic subjects. Comparison of electrodiagnostic results indicated no correlations between the MR parameters and electrophysiologic dysfunction of the median nerve for patients.

CONCLUSION

The only statistically significant differences found between patients with carpal tunnel syndrome and asymptomatic subjects were that the median nerve was approximately 50% larger within and proximal to the carpal tunnel in patients with carpal tunnel syndrome and palmar bowing of the flexor retinaculum occurred in patients only at the level of the hamate.

Zinc modulates antagonist interactions with D2-like dopamine receptors through distinct molecular mechanisms

Recently, zinc has been shown to modulate antagonist drug interactions with the D1 dopamine receptor (Schetz and Sibley, 1997) and the dopamine transporter (Norregaard et al., 1998). We now demonstrate that zinc also reversibly and dose-dependently modulates the specific binding of the butyrophenone antagonist [3H]methylspiperone to all D2-like dopamine receptors: D2L, D3, and D4. The molecular mechanisms of zinc regulation of these D2-like receptor subtypes are distinct because zinc inhibition of [3H]methylspiperone binding to the D4 receptor is noncompetitive by both equilibrium and kinetic measures (lower Bmax and essentially no change in koff), whereas the corresponding inhibition of zinc at D2L and D3 receptors is primarily characterized by competitive allosterism (increases in KD and koff). Interestingly, thermodynamic measurements reveal that the macroscopic properties of zinc binding are entropy-driven for all receptor subtypes, despite their having distinct molecular mechanisms. Zinc also reduces the binding affinity of the D2L receptor for [3H]raclopride, a structurally different antagonist of the substituted benzamide class. Sodium ions negatively modulate zinc inhibition of both sodium-insensitive [3H]methylspiperone binding and sodium-sensitive [3H]raclopride binding. In addition to its demonstrated effects on antagonist binding in membrane preparations, zinc also retards the functional effects of antagonist at the D2L receptor in intact cells. These findings suggest that synaptic zinc may be a factor influencing the effectiveness of therapies that rely on dopamine receptor antagonists.

A comparison of a new polypropylene suture with Prolene

The purpose of this paper is to examine the performance of the newly available monofilament polypropylene suture (Surgipro) manufactured by U.S. Surgical and compare it with commercial Prolene sutures for determining the merit of this new suture. Two different sizes of Surgipro sutures were used. They were 4/0 and 0 sizes and were tested in terms of their fundamental properties: level of crystallinity, melting temperature, fiber morphology, and mechanical properties including knot strength and knot security. The effect of three different sterilization methods on the mechanical and fundamental properties of the new polypropylene (PP) sutures was also examined. In general, the new Surgipro sutures performed as good as Prolene sutures in terms of mechanical properties; but there were some differences in fundamental properties between these two types of PP sutures, particularly in finer size PP sutures. The major differences were in interior fiber morphology, level of crystallinity, and melting temperature. Surgipro suture fibers showed homogeneous interior morphology, while Prolene fibers exhibited two distinctive fiber morphologies. These two types of PP suture fibers also responded differently to the three sterilization methods tested. Surgipro sutures are less affected by different sterilization methods than the same size Prolene control. Except for the Co 60 gamma sterilization, Surgipro suture fibers did not exhibit statistically significant differences in tensile breaking strength between sterilized and control. Ethylene oxide and autoclave sterilized Prolene suture fibers, however, showed statistically (p less than 0.05) consistently lower tensile breaking strength than their unsterilized controls.(ABSTRACT TRUNCATED AT 250 WORDS)

Velcro in the nuclear envelope: LBR and LAPs

The nuclear envelope is crucial for the functional organization of the nucleus. Lamin B receptor (LBR) and several lamina-associated proteins (LAPs), residing in the inner membrane, provide attachment sites for chromatin and the nuclear lamina. LAPs and LAP-related proteins are members of a growing family of proteins, whose genes are expressed in a tissue and development specific manner, opening the opportunity for a complex regulation of membrane-chromatin and membrane-lamina interactions. Post-translational modifications of LBR and LAPs are likely to modulate their binding to lamins and chromatin, interactions that need to be dynamic to accommodate nuclear growth in interphase and nuclear envelope disassembly in mitosis. Accumulation of proteins in the inner nuclear membrane is believed to depend on their retention mediated by the interaction with nuclear components such as chromatin and lamins.

Oxazolone colitis: A murine model of T helper cell type 2 colitis treatable with antibodies to interleukin 4

In this study we describe oxazolone colitis, a new form of experimental colitis. This model is induced in SJL/J mice by the rectal instillation of the haptenating agent, oxazolone, and is characterized by a rapidly developing colitis confined to the distal half of the colon; it consists of a mixed neutrophil/lymphocyte infiltration limited to the superficial layer of the mucosa which is associated with ulceration. Oxazolone colitis is a T helper cell type 2 (Th2)-mediated process since stimulated T cells from lesional tissue produce markedly increased amounts of interleukin (IL)-4 and IL-5; in addition, anti-IL-4 administration leads to a striking amelioration of disease, whereas anti-IL-12 administration either has no effect or exacerbates disease. Finally, this proinflammatory Th2 cytokine response is counterbalanced by a massive transforming growth factor-beta (TGF-beta) response which limits both the extent and duration of disease: lesional (distal) T cells manifest a 20-30-fold increase in TGF-beta production, whereas nonlesional (proximal) T cells manifest an even greater 40-50-fold increase. In addition, anti-TGF-beta administration leads to more severe inflammation which now involves the entire colon. The histologic features and distribution of oxazolone colitis have characteristics that resemble ulcerative colitis (UC) and thus sharply distinguish this model from most other models, which usually resemble Crohn's disease. This feature of oxazolone colitis as well as its cytokine profile have important implications to the pathogenesis and treatment of UC.

Electromagnetic field-induced stimulation of Bruton's tyrosine kinase

Here we present evidence that exposure of DT40 lymphoma B-cells to low energy electromagnetic fields (EMF) results in activation of phospholipase C-gamma 2 (PLC-gamma2), leading to increased inositol phospholipid turnover. PLC-gamma2 activation in EMF-stimulated cells is mediated by stimulation of the Bruton's tyrosine kinase (BTK), a member of the Src-related TEC family of protein tyrosine kinases, which acts downstream of LYN kinase and upstream of PLC-gamma2. B-cells rendered BTK-deficient by targeted disruption of the btk gene did not show enhanced PLC-gamma2 activation in response to EMF exposure. Introduction of the wild-type (but not a kinase domain mutant) human btk gene into BTK-deficient B-cells restored their EMF responsiveness. Thus, BTK exerts a pivotal and mandatory function in initiation of EMF-induced signaling cascades in B-cells.

Stimulation of Src family protein-tyrosine kinases as a proximal and mandatory step for SYK kinase-dependent phospholipase Cgamma2 activation in lymphoma B cells exposed to low energy electromagnetic fields

Here, we present evidence that exposure of DT40 lymphoma B cells to low energy electromagnetic field (EMF) results in a tyrosine kinase-dependent activation of phospholipase Cgamma2 (PLC-gamma2) leading to increased inositol phospholipid turnover. B cells rendered PLC-gamma2-deficient by targeted disruption of the PLC-gamma2 gene as well as PLC-gamma2-deficient cells reconstituted with Src homology domain 2 (SH2) domain mutant PLC-gamma2 did not show any increase in inositol-1,4,5-trisphosphate levels after EMF exposure, providing direct evidence that PLC-gamma2 is responsible for EMF-induced stimulation of inositol phospholipid turnover, and its SH2 domains are essential for this function. B cells rendered SYK-deficient by targeted disruption of the syk gene did not show PLC-gamma2 activation in response to EMF exposure. The C-terminal SH2 domain of SYK kinase is essential for its ability to activate PLC-gamma2. SYK-deficient cells reconstituted with a C-terminal SH2 domain mutant syk gene failed to elicit increased inositol phospholipid turnover after EMF exposure, whereas SYK-deficient cells reconstituted with an N-terminal SH2 domain mutant syk gene showed a normal EMF response. LYN kinase is essential for the initiation of this biochemical signaling cascade. Lymphoma B cells rendered LYN-deficient through targeted disruption of the lyn gene did not elicit enhanced inositol phospholipid turnover after EMF exposure. Introduction of the wild-type (but not a kinase domain mutant) mouse fyn gene into LYN-deficient B cells restored their EMF responsiveness. B cells reconstituted with a SH2 domain mutant fyn gene showed a normal EMF response, whereas no increase in inositol phospholipid turnover in response to EMF was noticed in LYN-deficient cells reconstituted with a SH3 domain mutant fyn gene. Taken together, these results indicate that EMF-induced PLC-gamma2 activation is mediated by LYN-regulated stimulation of SYK, which acts downstream of LYN kinase and upstream of PLC-gamma2.

Malaria surveillance in New York City: 1991-1996

BACKGROUND

The transmission of malaria has increased in recent years in many countries where it was once eradicated or under control, and malaria remains a major cause of morbidity and mortality throughout the developing world. Imported cases of malaria have been increasing in New York City and throughout the United States during the past decade. The New York City Department of Health has modified its malaria surveillance program in order to improve the assessment of diagnosis and treatment of malaria in New York City residents and to provide appropriate advice to health professionals who treat these patients.

OBJECTIVES

To describe the epidemiologic and clinical characteristics of laboratory-confirmed cases of malaria diagnosed in New York City residents from January 1, 1991, through December 31, 1996.

METHODS

The retrospective study of case reports was carried out by the Malaria Surveillance Program of the Bureau of Communicable Diseases, New York City Department of Health, New York City, NY. It included the laboratory diagnosis of malaria and the species involved, and included also descriptive epidemiologic information of patients with malaria (age, sex, race/ethnicity, date and place of onset of illness, travel history, immigration status, previous history of malaria, history of blood transfusion, drugs used for treatment or prophylaxis), as well as a record of clinical complications of the infection (thrombocytopenia, hemolysis, anemia, cerebral malaria, renal failure, respiratory distress syndrome, fatal outcome).

RESULTS

Malaria was diagnosed in 988 residents of New York City during the 5-year period from January 1, 1991, through December 31, 1995. The largest number of cases, 254 (26%), occurred in 1996, with the majority of these cases (76%) observed between the months of May and October. Sixty-four percent (627) of these cases were males. The age range of cases was from newborn (first day of life) to 83 years (median, 31 years). Of the 962 cases of whom the racial/ethnic identity was known, 580 (59%) were black/non-Hispanic and 255 (26%) were Asian/Pacific Islander. Travel outside of the United States was reported by 958 patients, the majority to Africa (569/958, 59%). Only 139 patients (14%) claimed the use of malaria prophylaxis during travel. Plasmodium falciparum was identified in 505 (51%) and P. vivax in 356 (36%) of the cases. Clinical complications included hemolysis with severe anemia, thrombocytopenia, cerebral malaria, renal failure, and respiratory distress syndrome. All four fatal cases involved infections with P. falciparum, either alone or in combination with another plasmodia species.

CONCLUSIONS

Imported cases of malaria occur frequently in New York City and may be associated with serious complications. Health care providers should consider this diagnosis in patients who have recently travelled or arrived from abroad, presenting with headache, fever, and other constitutional symptoms. There are many missed opportunities for the use of malaria prophylaxis, and physicians should familiarize themselves with current recommendations for malaria prophylaxis for travel to areas of the world where people are at risk for the transmission of malaria.

Interaction between the adhesion receptor, CD44, and the oncogene product, p185HER2, promotes human ovarian tumor cell activation

In this study we have examined the interaction between CD44s (the standard form) and the p185(HER2) proto-oncogene in the ovarian carcinoma cell line. Surface biotinylation followed by wheat germ agglutinin column chromatography and anti-CD44-mediated immunoprecipitation indicate that both CD44s and p185(HER2) are expressed on the cell surface and most importantly, that these two molecules are physically linked to each other via interchain disulfide bonds. We have also determined that hyaluronic acid stimulates CD44s-associated p185(HER2) tyrosine kinase activity, leading to an increase in the ovarian carcinoma cell growth. After transfection of the ovarian carcinoma cell line with the adenovirus 5 E1A gene, which is known to repress p185(HER2) expression, we observed that both surface CD44s expression and CD44s-mediated cell adhesion to hyaluronic acid are significantly reduced in the transfectant cells compared with the control cells. These data suggest that down-regulation of p185(HER2) blocks CD44s expression and subsequent adhesion function. Our findings also indicate that the CD44s-p185(HER2) interaction is both functionally coupled and biosynthetically regulated. We believe that direct "cross-talk" between these two surface molecules (i.e. CD44s and the p185(HER2)) may be one of the most important signaling events in human ovarian carcinoma development.

Effects of coat protein mutations and reduced movement protein expression on infection spread by cowpea chlorotic mottle virus and its hybrid derivatives

Previously we have reported that the essential 3a movement gene of icosahedral cowpea chlorotic mottle virus (CCMV) can be functionally replaced by the 30-kDa movement gene of rod-shaped sunn-hemp mosaic virus (SHMV). Because plant RNA viruses differ in requiring or not requiring coat protein for systemic infection, we have now investigated whether systemic spread by this CCMV/SHMV hybrid is dependent on its CCMV coat protein as well as its SHMV movement protein. We find that either deletion or frameshift mutations in the coat protein gene block systemic spread. Thus, like wild-type CCMV, systemic infection by the hybrid is dependent on both movement protein and coat protein. These results further support the conclusion that the required functions of the coat and movement proteins in CCMV spread do not depend on sequence-specific interaction between these proteins. Additional features of the hybrid also motivated testing the effects of modulating movement protein expression. Creating an extra, out-of-frame translational start codon (AUG) shortly upstream of the 3a movement protein gene in CCMV downregulated its expression 18-fold. Nevertheless, for CCMV derivatives bearing either the CCMV 3a gene or the SHMV 30-kDa gene, the extra AUG resulted in only a minor delay in the onset of viral spread and little or no effect on the subsequent rate of cell-to-cell spread. Thus, under normal circumstances, the rate of CCMV cell-to-cell spread in cowpea plants appears to be limited primarily by factors other than movement protein synthesis.

An STS-based radiation hybrid map of the human genome

We have constructed a physical map of the human genome by using a panel of 83 whole genome radiation hybrids (the Stanford G3 panel) in conjunction with 10,478 sequence-tagged sites (STSs) derived from random genomic DNA sequences, previously mapped genetic markers, and expressed sequences. Of these STSs, 5049 are framework markers that fall into 1766 high-confidence bins. An additional 945 STSs are indistinguishable in their map location from one or more of the framework markers. These 5994 mapped STSs have an average spacing of 500 kb. An additional 4484 STSs are positioned with respect to the framework markers. Comparison of the orders of markers on this map with orders derived from independent meiotic and YAC STS-content maps indicates that the error rate in defining high-confidence bins is < 5%. Analysis of 322 random cDNAs indicates that the map covers the vast majority of the human genome. This STS-based radiation hybrid map of the human genome brings us one step closer to the goal of a physical map containing 30,000 unique ordered landmarks with an average marker spacing of 100 kb.

Stable expression of CD1a molecule in human epithelial cell lines shows temperature-dependent expression and affects cell morphology and growth

The human CD1a molecule is a transmembrane protein which shares structural similarities with HLA class I molecules. It has restricted tissue distribution in normal individuals, and is a useful diagnostic marker for certain disease states such as Langerhans cell histiocytosis. In order to investigate the function of this molecule, a cDNA fragment encoding the CD1a molecule was cloned into several EUKARYOTIC expression vectors which were then used to establish human epithelial cell lines stably expressing the membrane-bound CD1a molecule. Human keratinocytes (HaCaT) and epithelial cells (HeLa) stably expressing CD1a were established by retroviral-mediated gene transfer and DNA transfection, respectively. Expression and localization of the CD1A molecule were then confirmed by Northern blot analysis and immunofluorescence methods. CD1a expression appears to have profound effects on cellular growth and morphology. Both stably CD1a-expressing HeLa and HaCaT cells showed increased doubling times, and up to 20% of CD1a-expressing cells showed altered cell morphology. Clonogenicity experiments demonstrated a reduction in colony size and plating efficiency was augmented in CD1a-positive cells when compared with vector-transfected/infected controls. Our findings suggest that CD1A expression may act as a negative growth regulator in these cells in vitro. Furthermore, lower temperatures greatly enhanced the expression of CD1a at both the protein and mRNA levels in a time-dependent fashion. Since the physiological skin temperatures lie well below the core temperature, this observation may have important implications in the study of Langerhans cells in vitro.

The comparative efficacy of benzoyl peroxide 5%/erythromycin 3% gel and erythromycin 4%/zinc 1.2% solution in the treatment of acne vulgaris

This randomized 10-week study compared the efficacy of benzoyl peroxide 5%/erythromycin 3% gel with erythromycin 4%/zinc 1.2% solution in 72 acne vulgaris patients. Physician global evaluations were significantly more improved (P < or = 0.05) in the benzoyl peroxide 5%/erythromycin 3% gel treatment group compared to erythromycin 4%/zinc 1.2% solution at week 2 and at each subsequent biweekly clinical visit. Inflammatory lesions (papules/pustules) were significantly more reduced (P < or = 0.005) in the benzoyl peroxide 5%/erythromycin 3% gel treatment group than the erythromycin 4%/zinc 1.2% solution at weeks 4 and 10. Comedones were significantly more reduced (P < or = 0.001) in the benzoyl peroxide 5%/erythromycin 3% gel treatment group than in the erythromycin 4%/zinc 1.2% solution group at weeks 8 and 10. Patient efficacy evaluations significantly (P < or = 0.001) favoured benzoyl peroxide 5%/erythromycin 3% gel to erythromycin 4%/zinc 1.2% solution.

G alpha(i-2) mediates renal LLC-PK1 growth by a Raf-independent activation of p42/p44 MAP kinase

The protooncogene G alpha(i-2) plays a pivotal role in signaling pathways that control renal cell growth and differentiation. Mitogen-activated protein kinases (MAPKs) are potential downstream effectors for G alpha(i-2) in these pathways. In predifferentiated LLC-PK1 renal cells, the temporal maximal expression of G alpha(i-2) coincided with maximal activation of MAPK(p42/p44). By contrast, pertussis toxin treatment of these cells inhibited cell growth and reduced MAPK(p42/p44) activity by 30%. These findings reflected upstream activation of MAPK kinase (MEK1), as transient transfection of cells with a plasmid encoding a constitutively active form of MEK1 increased MAPK(p42/p44) activity and cell growth, whereas treatment with PD-098059, an inhibitor of MEK1 activity, reduced MAPK(p42/p44) activity and cell growth. Expression of a guanosinetriphosphatase (GTPase)-deficient G alpha(i-2) in these cells increased MAPK(p42/p44) activity and correspondingly reduced cell doubling time from 24 to 10 h without altering the activity of Raf-1 or c-Jun/stress-activated protein kinases (SAPKs). By contrast, expression of a GTPase-deficient G alpha(i-3) in these cells reduced both their cell doubling time by 30% and MAPK(p42/p44) activity by 60%. As the known MEKK isoforms (MEKK1, -2, and -3) can also activate SAPKs, these findings suggest the GTP-charged G alpha(i-2) subunit transduces growth signals in renal cells via activation of MAPK(p42/p44) and that such activation may be linked to pathways containing novel MEKK isoforms that preferentially activate MEKs.

Validation of a new UNIX-based quantitative coronary angiographic system for the measurement of coronary artery lesions

We describe a method of validation of computerized quantitative coronary arteriography and report the results of a new UNIX-based quantitative coronary arteriography software program developed for rapid on-line (digital) and off-line (digital or cinefilm) analysis. The UNIX operating system is widely available in computer systems using very fast processors and has excellent graphics capabilities. The system is potentially compatible with any cardiac digital x-ray system for on-line analysis and has been designed to incorporate an integrated database, have on-line and immediate recall capabilities, and provide digital access to all data. The accuracy (mean signed differences of the observed minus the true dimensions) and precision (pooled standard deviations of the measurements) of the program were determined x-ray vessel phantoms. Intra- and interobserver variabilities were assessed from in vivo studies during routine clinical coronary arteriography. Precision from the x-ray phantom studies (6-In. field of view) for digital images was 0.066 mm and for digitized cine images was 0.060 mm. Accuracy was 0.076 mm (overestimation) for digital images compared to 0.008 mm for digitized cine images. Diagnostic coronary catheters were also used for calibration; accuracy.varied according to size of catheter and whether or not they were filled with iodinated contrast. Intra- and interobserver variabilities were excellent and indicated that coronary lesion measurements were relatively user-independent. Thus, this easy to use and very fast UNIX based program appears to be robust with optimal accuracy and precision for clinical and research applications.

(+)-Pinoresinol/(+)-lariciresinol reductase from Forsythia intermedia. Protein purification, cDNA cloning, heterologous expression and comparison to isoflavone reductase

Lignans are a widely distributed class of natural products, whose functions and distribution suggest that they are one of the earliest forms of defense to have evolved in vascular plants; some, such as podophyllotoxin and enterodiol, have important roles in cancer chemotherapy and prevention, respectively. Entry into lignan enzymology has been gained by the approximately 3000-fold purification of two isoforms of (+)-pinoresinol/(+)-lariciresinol reductase, a pivotal branchpoint enzyme in lignan biosynthesis. Both have comparable ( approximately 34.9 kDa) molecular mass and kinetic (Vmax/Km) properties and catalyze sequential, NADPH-dependent, stereospecific, hydride transfers where the incoming hydride takes up the pro-R position. The gene encoding (+)-pinoresinol/(+)-lariciresinol reductase has been cloned and the recombinant protein heterologously expressed as a functional beta-galactosidase fusion protein. Its amino acid sequence reveals a strong homology to isoflavone reductase, a key branchpoint enzyme in isoflavonoid metabolism and primarily found in the Fabaceae (angiosperms). This is of great evolutionary significance since both lignans and isoflavonoids have comparable plant defense properties, as well as similar roles as phytoestrogens. Given that lignans are widespread from primitive plants onwards, whereas the isoflavone reductase-derived isoflavonoids are mainly restricted to the Fabaceae, it is tempting to speculate that this branch of the isoflavonoid pathway arose via evolutionary divergence from that giving the lignans.

A gene map of the human genome

The human genome is thought to harbor 50,000 to 100,000 genes, of which about half have been sampled to date in the form of expressed sequence tags. An international consortium was organized to develop and map gene-based sequence tagged site markers on a set of two radiation hybrid panels and a yeast artificial chromosome library. More than 16,000 human genes have been mapped relative to a framework map that contains about 1000 polymorphic genetic markers. The gene map unifies the existing genetic and physical maps with the nucleotide and protein sequence databases in a fashion that should speed the discovery of genes underlying inherited human disease. The integrated resource is available through a site on the World Wide Web at http://www.ncbi.nlm.nih.gov/SCIENCE96/.

Heteroduplex analysis in hemophilia B: detection of two novel factor IX gene mutations

Heteroduplex analysis of polymerase chain reaction (PCR)-amplified factor IX (FIX) sequences in eight hemophilia B pedigrees localized the causative hemophilia mutation to a single exon in each case. Subsequent PCR-based direct DNA sequence analysis identified two novel FIX mutations and six recurrent mutations. Three of the eight pedigrees represent sporadic hemophilia B, and direct mutation analysis facilitated hemophilia carrier diagnosis in each case.

A proliferation analysis of arterial neointimal hyperplasia: lessons for antiproliferative restenosis therapies

Medial smooth muscle cell proliferation is frequently implicated as the major cause of coronary restenosis. Although antiproliferative agents have shown efficacy in animal studies, they are ineffective in human trials. To better understand these discrepancies, we performed a mathematical kinetic analysis of cellular proliferation in the neointimal hyperplasia of rats, pigs, and patients. A model was derived using a differential expression for proliferation, proportional to the number of cells present. Additional terms were included for inhibition of proliferation proportional to neointimal mass and time. The resulting equation was solved in closed form for the number of cells and proliferation rate. These equations were validated in the rat carotid artery injury model from published data. The model was then applied to the porcine coronary injury model, and then to clinical data obtained from angiographic human studies. Peak cellular proliferative activity in patients occurs at 16 days and continues at lower levels for much longer periods of time. Less than 10 generations of cells are sufficient to develop clinically significant restenosis. Conversely, proliferation rates in the two animal models (rats and pigs) are maximal at roughly 2 and 6 days, respectively, also continuing at low levels for extended time periods. Cell proliferation in restenosis is a highly controlled process, with comparatively few cell generations causing enough neointima for arterial obstruction to occur. Substantial cell kinetic differences occur across species. The rat exhibits high proliferation rates and rapid doubling times compared to patients and pigs, and is thus a highly 'proliferative' model. Such differences may be responsible for discrepant animal model and clinical trial results. These data may help determine the timing and strategy of therapy against clinical restenosis.

Coding changes in the 3a cell-to-cell movement gene can extend the host range of brome mosaic virus systemic infection

The M1 and M2 strains of brome mosaic virus (BMV) both systemically infect the monocot host barley, but only the M2 strain systemically infects the dicot cowpea line TVu-612. We have shown previously that this difference in host range maps primarily to RNA3. To further characterize the role of RNA3 in host specificity, a series of RNA3 hybrids were tested, in inoculations with M1 RNA1 and RNA2, for ability to systemically infect TVu-612 cowpea. Although all hybrids were amplified well in cowpea protoplasts and all supported systemic infection in barley plants, only those with the 3a cell-to-cell movement gene of BMV-M2 supported systemic infection of cowpea. The sequences of the M1 and M2 3a proteins differ at four positions. Introducing these four coding differences individually or in various combinations into M1 RNA3 revealed that all four influenced BMV adaptation to cowpea and that these four differences were sufficient to account for the difference in ability between M1 and M2 RNA3s to support systemic infection of this legume. These coding changes were also associated with faster spread of infection in inoculated cowpea leaves, suggesting that they influence the ability to systemically infect TVu-612 cowpea through effects on the rate of cell-to-cell spread.