Mortality in Chicago attributed to the July 1995 heat wave

OBJECTIVES

This study assessed mortality associated with the mid-July 1995 heat wave in Chicago.

METHODS

Analyses focused on heat-related deaths, as designated by the medical examiner, and on the number of excess deaths.

RESULTS

In July 1995, there were 514 heat-related deaths and 696 excess deaths. People 65 years of age or older were overrepresented and Hispanic people underrepresented. During the most intense heat (July 14 through 20), there were 485 heat-related deaths and 739 excess deaths.

CONCLUSIONS

The methods used here provide insight into the great impact of the Chicago heat wave on selected populations, but the lack of methodological standards makes comparisons across geographical areas problematic.

Lyn associates with the juxtamembrane region of c-Kit and is activated by stem cell factor in hematopoietic cell lines and normal progenitor cells

Stem cell factor (SCF) is a cytokine critical for normal hematopoiesis. The receptor for SCF is c-Kit, a receptor tyrosine kinase. Our laboratory is interested in delineating critical components of the SCF signal transduction pathway in hematopoietic tissue. The present study examines activation of Src family members in response to SCF. Stimulation of cell lines as well as normal progenitor cells with SCF rapidly increased tyrosine phosphorylation of the Src family member Lyn. Peak responses were noted 10-20 min after SCF treatment, and phosphorylation of Lyn returned to basal levels 60-90 min after stimulation. SCF also induced increases in Lyn kinase activity in vitro. Lyn coimmunoprecipitated with c-Kit, and studies with GST fusion proteins demonstrated that Lyn readily associated with the juxtamembrane region of c-Kit. Treatment of cells with either Lyn antisense oligonucleotides or PP1, a Src family inhibitor, resulted in dramatic inhibition of SCF-induced proliferation. These data demonstrate that SCF rapidly activates Lyn and suggest that Lyn is critical in SCF-induced proliferation in hematopoietic cells.

IL-7 administration alters the CD4:CD8 ratio, increases T cell numbers, and increases T cell function in the absence of activation

IL-7 is vital for the development of the immune system and profoundly enhances the function of mature T cells. Chronic administration of IL-7 to mice markedly increases T cell numbers, especially CD8(+) T cells, and enhances T cell functional potential. However, the mechanism by which these effects occur remains unclear. This report demonstrates that only 2 days of IL-7 treatment is needed for maximal enhancement of T cell function, as measured by proliferation, with a 6- to 12-fold increase in the proportion of CD4(+) and CD8(+) T cells in cell cycle by 18 h of ex vivo stimulation. Moreover, a 2-day administration of IL-7 in vivo increases basal proliferation by 4- and 14-fold in CD4(+) and CD8(+) T cells, respectively. These effects occur in the absence of cytokine production, increases in most activation markers, and changes in memory markers. This enhanced basal proliferation is the basis for the increase in T cell numbers in that IL-7 induces an additional 60% and 85% of resting CD4(+) and CD8(+) T cells, respectively, to enter cell cycle in mice given IL-7 for 7 days. These results demonstrate that in vivo administration of IL-7 increases T cell numbers and functional potential via a homeostatic, nonactivating process. These findings may suggest a unique clinical niche for IL-7 in that IL-7 therapy may increase T cell numbers and enhance responses to specific antigenic targets while avoiding a general, nonspecific activation of the T cell population.

Stat1 associates with c-kit and is activated in response to stem cell factor

Interaction of stem cell factor (SCF), a haematopoietic growth factor, with the receptor tyrosine kinase c-kit leads to autophosphorylation of c-kit as well as tyrosine phosphorylation of various substrates. Little is known about the role of the JAK/STAT pathway in signal transduction via receptor tyrosine kinases, although this pathway has been well characterized in cytokine receptor signal transduction. We recently found that the Janus kinase Jak2 associates with c-kit and that SCF induces rapid and transient phosphorylation of Jak2. Here we present evidence that SCF activates the transcription factor Stat1. Phosphorylated c-kit co-immunoprecipitates with Stat1 within 1 min of SCF stimulation of the human cell line MO7e. Co-precipitation experiments using glutathione S-transferase fusion proteins indicate that association with c-kit is mediated by the Stat1 SH2 domain. Stat1 is rapidly tyrosine-phosphorylated in response to SCF in MO7e cells, the murine cell line FDCP-1 and normal progenitor cells. SCF-induced phosphorylation of Jak2 and Stat1 was also observed in murine 3T3 fibroblasts stably transfected with full-length human c-kit receptor. Furthermore c-kit directly phosphorylates Stat1 fusion proteins in in vitro kinase assays. Electrophoretic mobility-shift assays with nuclear extracts from SCF-stimulated cell lines and normal progenitor cells indicate that activated Stat1 binds the m67 oligonucleotide, a high-affinity SIE promoter sequence. These results demonstrate that Stat1 is activated in response to SCF, and suggest that Stat1 is a component of the SCF signal-transduction pathway.

Preparation and blood compatibility of polysiloxane/liquid-crystal composite membranes

Polysiloxane/liquid crystal composite membrane was first suggested to be used as biomaterials. In this work, the polydimethyl-methylhydrosiloxane and polydimethyl-methylethylenesilosiane, as a substrate, were blended with cholesteryl oleyl carbonate (COC) in tetrahydrofuran, and then crosslinked into membranes on glass plates by means of the platinum catalyst at 110 degrees C for 20 min. The effects of the liquid-crystal content in composite membranes on the formation of liquid-crystal phase were verified by the observation of optical polarization microscopy. The relationship between the morphology of the composite membranes and blood compatibility was identified by the dynamic blood-clotting tests, haemolysis ratio measurement, platelet adhesion and SEM observation. The results show that the blood-compatibility of composite membranes with the concentration of liquid crystal 20, 30% (wt) is more excellent than that of other composite membranes.

A new strategy to replace the natural vitreous by a novel capsular artificial vitreous body with pressure-control valve

PURPOSE

The current vitreous substitutes such as silicone oil, heavy silicone oil, and polymeric gels that are directly injected into vitreous cavity frequently cause severe intraocular complications. There is a very urgent need to find a more suitable artificial vitreous substitute for pars plana vitrectomy (PPV) surgery.

METHODS

We have devised a novel capsular artificial vitreous using tailor-made silicone rubber elastomer. The novel device was implanted into the vitreous cavity of rabbit after PPV and the eye was examined by ophthalmoscopy, fundus photography, and tonometry during an 8-week treatment period. B-scan ultrasonography, electroretinogram (ERG), and histological studies by light microscopy were also performed at the end of 8 weeks.

RESULTS

The novel artificial vitreous body consists of a thin vitreous-like capsule with a silicone tube-valve system. The capsule can be folded and implanted into vitreous cavity through 1.5 mm incision on sclera. Physiological balanced solution (PBS) was then injected into the capsule and inflated to support retina and control intraocular pressure (IOP) through the tube-valve system subsequently fixed under the conjunctiva. Experiments using rabbits showed that the novel vitreous body could effectively support the retina and apparently induced no significant pathological changes in the eye over 8 weeks.

CONCLUSION

This approach may provide a new research strategy in the vitreous replacement technology. The novel artificial vitreous body device can effectively support retina, control IOP, and has good biocompatibility. It may be a good alternative to injecting artificial vitreous although its tamponade properties and usefulness still have to be proven in complex vitreoretinal diseases.

Ion chromatographic analysis of tetracyclines using polymeric column and acidic eluent

High-performance ion chromatography (HPIC) is first successfully used to analyze tetracycline antibiotics (TCs) in this work. The TCs are well separated on a solvent compatible polymeric cation-exchange column within 12 min. Isocratic elution with acetonitrile-hydrochloride is very advantageous for routine analysis. HPIC may be seen as a specific variant of the more common high-performance liquid chromatography (HPLC) for water-soluble and polar pharmaceuticals with low hydrophobicity. The detection limits (signal-to-noise ratio=3:1) of oxytetracycline (OTC), tetracycline (TC), chlortetracycline (CTC), doxycycline (DC) are 10, 10, 20 and 20 microg l(-1), respectively. Samples are prepared by vortex mixing with an ethylenediaminetetraacetic acid disodium salt (Na2EDTA)-McIlvaine buffer (pH 4.0) solution and the mixture filtrates through a molecular weight cut-off filter. The method has been successfully applied to monitor the OTC removal rate through every reactor in the process of OTC manufacturing wastewater treatment by bio-chemical technology. It is also applicable to determine the TCs residues in milk and milk powder with satisfying results.

Stem cell factor, the JAK-STAT pathway and signal transduction

Recent work has demonstrated the importance of Janus family kinases (JAKs) and signal transducers and activators of transcription (STATs) in the stimulus-response coupling of receptors lacking intrinsic tyrosine kinase activity. In particular, the JAK-STAT pathway appears critical in signal transduction by interferon as well as numerous hematopoietic growth factors interacting with members of the hemapoietin receptor superfamily. Although ligands that interact with receptor tyrosine kinases (RTK), such as epidermal growth factor (EGF), platelet-derived growth factor (PDGF) and colony stimulating factor-1 (CSF-1), have been shown to induce increases in phosphorylation of both JAKs and STATs, little is known about activation of this pathway by stem cell factor (SCF). This review will summarize what is known about the JAK/STAT pathway in relation to SCF signal transduction.

On-line pretreatment and determination of Pb, Cu and Cd at the microgram l-1 level in drinking water by chelation ion chromatography

A novel, highly sensitive method for the simultaneous separation and determination of lead, copper, cadmium and other transition metals in drinking water was achieved by on-line sample pretreatment of chelation ion chromatography. Manganese, which coeluted with cadmium, was oxidized to permanganate by ammonium persulfate before injection. Permanganate, with bulk quantity of alkali, alkaline earth metals, iron and aluminum, was eliminated by pyrophosphoric acid-ammonium acetate buffer solution (pH 5.5), while retaining heavy and transition metals on a selective chelating resin (MetPac CC-1 column). Then, they were disabsorbed and transferred to a sulfonated cation exchanger (TMC-1 column). Finally, the concentrated trace metals were separated on a bifunctional ion-exchange column (CS5A) by a concentration gradient of oxalic acid and sodium nitrate eluents, coupled with post-column spectrophotometric detection with 2-[(5-bromo-2-pyridyl)azo]-5-diethylaminophenol (5-Br-PADAP) at 560 nm. The separation and color-development conditions were optimized. The detection limits for the method (signal-to-noise ratio = 3:1) were at or below the microgram l-1 level. The results of drinking water analyses were satisfactory.

Photoprotection in the green tidal alga Ulva prolifera: role of LHCSR and PsbS proteins in response to high light stress

Ulva prolifera, an intertidal macroalga, has to adapt to wide variations in light intensity, making this species particularly rewarding for studying the evolution of photoprotective mechanisms. Intense light induced increased non-photochemical quenching (NPQ) and stimulated de-epoxidation of xanthophyll cycle components, while DTT-treated samples had lower NPQ capacity, indicating that the xanthophyll cycle must participate in photoprotection. In this work, we found that the PsbS-related NPQ was maintained in U. prolifera. According to analysed gene expression, both LhcSR and psbS were up-regulated in high light, suggesting that these two genes are light-induced. LHCSR and PsbS proteins were present at different light intensities and accumulated under high light conditions, and PsbS concentrations were higher than LHCSR, showing that the NPQ mechanism of U. prolifera is more dependent on PsbS protein concentration. Moreover, the level of both LHCSR and PsbS proteins was high even in the darkness, and neither the transcript level nor protein content of LhcSR and psbS genes varied significantly following short-term exposure to intense light. These findings suggest that this alga can modulate NPQ levels through regulation of the xanthophyll cycle and concentrations of PsbS and/or LHCSR.

JAK2 is constitutively associated with c-Kit and is phosphorylated in response to stem cell factor

Stem cell factor (SCF) interacts with the receptor tyrosine kinase c-Kit and has potent effects on hematopoiesis. We have examined the role of JAK2 in the SCF signal transduction pathway. JAK2 and c-Kit were constitutively associated, and treatment with SCF resulted in rapid and transient tyrosine phosphorylation of JAK2. Incubation of cells with JAK2 antisense oligonucleotides resulted in significant decreases in SCF-induced proliferation. These data suggest that JAK2 plays a role in SCF-induced proliferation.

Retention behavior of transition metals on a bifunctional ion-exchange column with oxalic acid as eluent

The common eluents used with a bifunctional ion-exchange column (IonPac CS5A) for separating transition metals are pyridine-2,6-dicarboxylic acid and oxalic acid (Ox). When Ox is used, cadmium and manganese co-elute. Although much research has been done to overcome the Cd2+-Mn2+ co-elution problem, the role of lithium hydroxide in separating the transition metals has received little attention. In this study, it is found that when the Ox concentration is higher than 35 mM, Cu2+ elutes after Pb2+ and Ox plays a predominant role in the retention behavior of the seven metals. When Ox concentration is lower than 35 mM especially when its concentration (25 mM) is half of the usually used standard concentration (50 mM), Cu2+ elutes before Pb2+, and at the same time, Mn2+ and Cd2+ can also be baseline separated. Lithium hydroxide plays a predominant role in the separation of the metals separated by cation exchange. So, lithium hydroxide is used to adjust the pH of the eluent. The use of an isocratic elution (25 mM Ox/LiOH/2 mM Na2SO4, pH 3.88) allows the separation of seven metals (Cu2+, Pb2+, Co2+, Mn2+, Cd2+, Zn2+ and Ni2+) in a single run. The effects of inorganic modifiers such as NaNO3, Na2SO4 and Na4P3O7 on retention behavior of the metals are also investigated.

Use of ion chromatography for the determination of heavy and transition metals in biochemical samples

A novel, highly sensitive method for simultaneous separation and determination of Cu2+, Ni2+, Zn2+, Cd2+, Co2+, Mn2+ and Pb2+ in biochemical samples was developed and evaluated by ion chromatography. All of these metals were well separated on a bifunctional ion-exchange column by a concentration gradient of oxalic acid and sodium chloride eluents, coupled with spectrophotometric detection after post-column derivatization with 2-[(5-bromo-2-pyridyl)azo]-5-diethylaminophenol at 560 nm. The method detection limits (signal-to-noise 3:1) were at microg l(-1) levels. The calibration graphs were linear (r2>0.999) over two-orders of magnitude. This technique was optimized and validated by analyzing five standard biochemical references.

Effects of albumin on ionized calcium in vitro

Human serum albumin is used to treat hypoproteinemia in neonates or used as a volume expander. We tested the hypothesis that the addition of human serum albumin to neonatal serum decreases the serum ionized calcium (iCa) concentration. Concentrated human serum albumin was added to 12 placental and cord serum samples to reach seven incremental concentrations from 0 to 20.0 g/L. Serum iCa concentration decreased significantly with the addition of serum albumin. From multiple regression analysis, the effect of albumin addition on serum iCa concentration had more marked effects at high baseline albumin or low baseline Ca concentrations. From this in vitro study, we speculate that fast infusion of albumin in human neonates has the potential for acutely lowering serum iCa concentration.

Comparison of clindamycin phosphate vaginal cream with triple sulfonamide vaginal cream in the treatment of bacterial vaginosis

BACKGROUND

Triple sulfonamide vaginal cream has been used to treat bacterial vaginosis for many years. There are few studies in which triple sulfonamide cream has been compared with newer regimens.

GOAL

To compare the efficacy and safety of clindamycin phosphate vaginal cream with that of triple sulfonamide vaginal cream in the treatment of bacterial vaginosis.

STUDY DESIGN

In this double-blind, randomized multicenter study, nonpregnant women 16 years of age or older with symptomatic bacterial vaginosis were assigned to receive either 2% clindamycin phosphate vaginal cream or triple sulfonamide vaginal cream for 7 days. Follow-up visits were conducted 5 to 10 days and 25 to 39 days after completion of treatment.

RESULTS

Clinical cure or improvement at 25 to 39 days was noted in 55 (69.6%) of 79 assessable participants who received clindamycin vaginal cream and in 33 (41.8%) of 79 women who received triple sulfonamide vaginal cream (P < 0.0001). Most of the difference between the treatment groups was noted in women with a history of bacterial vaginosis. Among women without a history of bacterial vaginosis, clindamycin and triple sulfonamide creams had similar efficacy. Evaluation of Gram-stained vaginal smears correlated with clinical outcome. Most patients in both treatment groups reported an improvement in symptoms. No significant difference was observed between the treatment groups in the incidence of adverse events.

CONCLUSION

Clindamycin 2% vaginal cream is more effective than triple sulfonamide vaginal cream in the treatment of bacterial vaginosis.

Combining S100B and Cytokines as Neuro-Inflammatory Biomarkers for Diagnosing Generalized Anxiety Disorder: A Proof-of-Concept Study Based on Machine Learning

INTRODUCTION

S100 calcium-binding protein B (S100B) is a neurotrophic factor that regulates neuronal growth and plasticity by activating astrocytes and microglia through the production of cytokines involved in Generalized Anxiety Disorder (GAD). However, few studies have combined S100B and cytokines to explore their role as neuro-inflammatory biomarkers in GAD.

METHODS

Serum S100B and cytokines (IL-1β, IL-2, IL-4, and IL-10) of 108 untreated GAD cases and 123 healthy controls (HC) were determined by enzyme-linked immunosorbent assay (ELISA), while Hamilton Anxiety Rating Scale (HAMA) scores and Hamilton Depression Rating Scale (HAMD) scores were measured to evaluate anxiety and depression severity. This was used to help physicians identify persons having GAD. Machine learning techniques were applied for feature ordering of cytokines and S100B and the classification of persons with GAD and HC.

RESULTS

The serum S100B, IL-1β, and IL-2 levels of GAD cases were significantly lower than HC (P < 0.001), and the IL-4 level in persons with GAD was significantly higher than HC (P < 0.001). At the same time, IL-10 had no significant difference between the two groups (P = 0.215). The feature ranking distinguishing GAD from HC using machine learning ranked the features in the following order: IL-2, IL-1β, IL-4, S100B, and IL-10. The accuracy of S100B combined with IL-1β, IL-2, IL-4, and IL-10 in distinguishing persons with GAD from HC was 94.47 ± 2.06% using an integrated back propagation neural network based on a bagging algorithm (BPNN-Bagging).

CONCLUSION

The serum S-100B, IL-1β, and IL-2 levels in persons with GAD were down-regulated while IL-4 was up-regulated. The combination of S100B and cytokines had a good diagnosis value in determining GAD with an accuracy of 94.47%. Machine learning was a very effective method to study neuro-inflammatory biomarkers interacting with each other and mediated by plenty of factors.

Effects of methadone use during pregnancy on human placental opioid receptors

Human placenta was used to investigate the effects of chronic methadone use during pregnancy on villus tissue opioid receptors. Patients included in this investigation received 35-60 mg methadone per day. Methadone-exposed placenta villus tissue had no detectable opioid receptor binding sites measured by tritiated opioid agonists. In vitro release of acetylcholine and hCG from trophoblast tissue of methadone-exposed placentas was not modulated by opioids. Absence of opioid receptor binding sites and their two mediated responses in trophoblast tissue of placentas obtained from patients with documented chronic methadone use during pregnancy indicate that the receptors were down regulated or desensitized.

Development and validation of a nomogram based on lymphocyte subsets to distinguish bipolar depression from major depressive disorder

OBJECTIVE

Bipolar depression (BD) and major depressive disorder (MDD) are both common affective disorders. The common depression episodes make it difficult to distinguish between them, even for experienced clinicians. Failure to properly diagnose them in a timely manner leads to inappropriate treatment strategies. Therefore, it is important to distinguish between BD and MDD. The aim of this study was to develop and validate a nomogram model that distinguishes BD from MDD based on the characteristics of lymphocyte subsets.

MATERIALS AND METHODS

A prospective cross-sectional study was performed. Blood samples were obtained from participants who met the inclusion criteria. The least absolute shrinkage and selection operator (LASSO) regression model was used for factor selection. A differential diagnosis nomogram for BD and MDD was developed using multivariable logistic regression and the area under the curve (AUC) with 95% confidence interval (CI) was calculated, as well as the internal validation using a bootstrap algorithm with 1,000 repetitions. Calibration curve and decision curve analysis (DCA) were used to evaluate the calibration and clinical utility of the nomogram, respectively.

RESULTS

A total of 166 participants who were diagnosed with BD (83 cases) or MDD (83 cases), as well as 101 healthy controls (HCs) between June 2018 and January 2022 were enrolled in this study. CD19⁺ B cells, CD3⁺ T cells, CD3^-CD16/56⁺ NK cells, and total lymphocyte counts were strong predictors of the diagnosis of BD and MDD and were included in the differential diagnosis nomogram. The AUC of the nomogram and internal validation were 0.922 (95%; CI, 0.879-0.965), and 0.911 (95% CI, 0.838-0.844), respectively. The calibration curve used to discriminate BD from MDD showed optimal agreement between the nomogram and the actual diagnosis. The results of DCA showed that the net clinical benefit was significant.

CONCLUSION

This is an easy-to-use, repeatable, and economical nomogram for differential diagnosis that can help clinicians in the individual diagnosis of BD and MDD patients, reduce the risk of misdiagnosis, facilitate the formulation of appropriate treatment strategies and intervention plans.

Selection rules for the orbital angular momentum of optically produced THz radiation

In this work, we theoretically study the transduction of orbital angular momentum (OAM) l for infrared pump lasers into the THz domain. In the case of optical rectification, the transduction of OAM occurs only through a spin-orbit interaction, with the selection rule on the OAM l=0 valid for any kind of polarization of the pump, which means that there is no transfer of OAM along the propagation axis. In difference frequency generation, the selection rule for the difference Δl between the OAM of the pump fields with linear or circular polarization is l=Δl, whereas l ranges from Δl-2 to Δl+2 in cases of both radial and azimuthal polarization. Moreover, for THz generation in the latter case, the high diffraction obtained with tightly focused pumps yields l tending to Δl±2, while l tends to zero in the opposite case of large pump beams.

The power spectrum and functional connectivity characteristics of resting-state EEG in patients with generalized anxiety disorder

Recent studies have suggested a relationship between abnormal neurophysiological functions and generalized anxiety disorder (GAD). However, studies on its electrophysiological characteristics, such as its power spectrum and functional connectivity are relatively few and scattered than those on other mental disorders (e.g., depression, ADHD, etc.). The present study aims to reveal the multidimensional electrophysiological characteristics of GAD via comparative analysis of electroencephalogram (EEG) data between GAD patients and healthy controls. Specifically, resting-state EEG, with a duration of 10 min, was recorded from 98 GAD patients and 92 healthy control participants. The electrophysiological characteristics, including the power spectrum, alpha asymmetry, and functional connectivity, were extracted and compared between the two groups. The results revealed significantly increased beta-band activity; decreased ipsilateral fronto-temporal and parieto-temporal functional connectivities in the lower frequency bands (theta-beta band); as well as decreased frontal‒parietal and frontal‒occipital connectivities in the higher frequency bands (beta‒gamma band) in GAD patients. Additionally, alpha asymmetry analysis revealed a significantly greater rightward temporal alpha asymmetry in GAD patients. These findings suggest the existence of significant EEG characteristics in patients with GAD, supporting previous conclusions regarding abnormal neurophysiological functions in psychiatric disorders and potentially leading to the identification of biomarkers for clinical diagnosis.