Utilizing mobile robotics for pelvic perturbations to improve balance and cognitive performance in older adults: a randomized controlled trial

Late-life balance disorders remain a severe problem with fatal consequences. Perturbation-based balance training (PBT), a form of rehabilitation that intentionally introduces small, unpredictable disruptions to an individual's gait cycle, can improve balance. The Tethered Pelvic Assist Device (TPAD) is a cable-driven robotic trainer that applies perturbations to the user's pelvis during treadmill walking. Earlier work showcased improved gait stability and the first evidence of increased cognition acutely. The mobile Tethered Pelvic Assist Device (mTPAD), a portable version of the TPAD, applies perturbations to a pelvic belt via a posterior walker during overground gait, as opposed to treadmill walking. Forty healthy older adults were randomly assigned to a control group (CG, n = 20) without mTPAD PBT or an experimental group (EG, n = 20) with mTPAD PBT for a two-day study. Day 1 consisted of baseline anthropometrics, vitals, and functional and cognitive measurements. Day 2 consisted of training with the mTPAD and post-interventional cognitive and functional measurements. Results revealed that the EG significantly outperformed the CG in several cognitive (SDMT-C and TMT-B) and functional (BBS and 4-Stage Balance: one-foot stand) measurements while showcasing increased confidence in mobility based on FES-I. To our knowledge, our study is the first randomized, large group (n = 40) clinical study exploring new mobile perturbation-based robotic gait training technology.

Utilizing Mobile Robotics for Pelvic Perturbations to Improve Balance and Cognitive Performance in Older Adults: A Randomized Controlled Trial

Late-life balance disorders remain a severe problem with fatal consequences. Perturbation-based balance training (PBT), a form of rehabilitation that intentionally introduces small, unpredictable disruptions to an individual's gait cycle, can improve balance. The Tethered Pelvic Assist Device (TPAD) is a cable-driven robotic trainer that applies perturbations to the user's pelvis during treadmill walking. Earlier work showcased improved gait stability and the first evidence of increased cognition acutely. The mobile Tethered Pelvic Assist Device (mTPAD), a portable version of the TPAD, applies perturbations to a pelvic belt via a posterior walker during overground gait, as opposed to treadmill walking. Forty healthy older adults were randomly assigned to a control group (CG, n = 20) without mTPAD PBT or an experimental group (EG, n = 20) with mTPAD PBT for a two-day study. Day 1 consisted of baseline anthropometrics, vitals, and functional and cognitive measurements. Day 2 consisted of training with the mTPAD and post-interventional cognitive and functional measurements. Results revealed that the EG significantly outperformed the CG in cognitive and functional tasks while showcasing increased confidence in mobility. Gait analysis demonstrated that the mTPAD PBT significantly improved mediolateral stability during lateral perturbations. To our knowledge, our study is the first randomized, large group (n = 40) clinical study exploring new mobile perturbation-based robotic gait training technology.

Surgical versus conservative management of tongue lacerations in the acute care setting: A systematic review of the literature

Objective

The objective of this study was to determine whether suturing or conservative management of tongue lacerations results in differences in wound healing and functional outcome. The secondary aim was to identify whether antibiotics are required in the treatment of tongue lacerations.

Methods

Studies published between December 1954 and August 2020 were extracted from MEDLINE via PubMed, Embase via OVID, CINAHL via EBSCO, Web of Science, and the Cochrane Library and evaluated for inclusion based on predetermined inclusion and exclusion criteria by two independent reviewers in accordance with PRISMA guidelines.

Results

The search yielded a total of 16,111 articles, 124 of which were evaluated by full-text review, resulting in 11 articles included in this systematic review representing 142 unique cases of tongue lacerations. At least 26 lacerations (18.3%) included penetration of the muscle layer of the tongue, and 24 (16.9%) were classified as full-thickness lacerations. Thirty-five of the 142 tongue lacerations (24.6%) were sutured. The remaining lacerations underwent some form of conservative management. The majority of studies reported excellent healing of tongue lacerations regardless of the management method, with minimal scarring and excellent return to normal functional status. No cases of infection were reported.

Conclusions

Current literature is inconsistent with regards to indications and guidelines for primary repair of tongue lacerations. The majority of tongue lacerations reported in the literature heal with excellent outcomes regardless of management method. Physician judgement along with patient and parental preference based on potential risks of the procedure should be used when deciding whether a tongue laceration requires primary repair. Tongue lacerations in otherwise healthy individuals are at very low risk of infection.

Antibiotic Prophylaxis in Alloplastic Breast Reconstruction: Regimens and Outcomes

PURPOSE

Surgical site infections (SSI) in prosthesis-based breast reconstruction can have a significant impact on patient outcome. Despite current CDC (Centers for Disease Control and Prevention) guidelines recommending 24 hours of postoperative antibiotics, various perioperative antimicrobial regimens are reported in the literature. Consensus on the optimal duration of antibiotics remains unclear. In this study, the aim is to compare the incidence of surgical site infections following different antibiotic durations in alloplastic breast reconstruction.

METHODS

In this retrospective cohort study, all consecutive patients who underwent expander/implant-based breast reconstruction between January 2009 and December 2014 at a tertiary centre were included. Data on patient demographics, risk factors, operative time, choice and timing of antibiotic used before surgery, and the duration of postoperative antibiotic use were collected. The primary outcome, SSI, is defined according to CDC criteria.

RESULTS

A total of 507 consecutive expander/implant-based cases were included. Minimum follow-up time was 1 year. The overall infection incidence was 14% (95% CI: 11%-17%), and the rate of subsequent explantation was 8%. Of the infected cases, 80% (45/56) received 1 week of postoperative antibiotic, while 20% (11/56) had a prolonged course of antibiotics (2-3 weeks; P = .003, odds ratio [OR] = 2.9; 95% CI: 1.4-5.8). Most infections were superficial (65%). Prior history of radiation treatment was identified as a risk factor for developing surgical site infection (P = .02).

CONCLUSION

Overall infection rate and risk factors for infections are in keeping with current literature. Prescribing one week of postoperative antibiotic was found to be associated with a higher incidence of SSI compared to a more prolonged antibiotic regimen.

Tipping the Scales With Zebrafish to Understand Adaptive Tumor Immunity

The future of improved immunotherapy against cancer depends on an in-depth understanding of the dynamic interactions between the immune system and tumors. Over the past two decades, the zebrafish has served as a valuable model system to provide fresh insights into both the development of the immune system and the etiologies of many different cancers. This well-established foundation of knowledge combined with the imaging and genetic capacities of the zebrafish provides a new frontier in cancer immunology research. In this review, we provide an overview of the development of the zebrafish immune system along with a side-by-side comparison of its human counterpart. We then introduce components of the adaptive immune system with a focus on their roles in the tumor microenvironment (TME) of teleosts. In addition, we summarize zebrafish models developed for the study of cancer and adaptive immunity along with other available tools and technology afforded by this experimental system. Finally, we discuss some recent research conducted using the zebrafish to investigate adaptive immune cell-tumor interactions. Without a doubt, the zebrafish will arise as one of the driving forces to help expand the knowledge of tumor immunity and facilitate the development of improved anti-cancer immunotherapy in the foreseeable future.

Vulvar apocrine hidradenocarcinoma arising in a hidradenoma papilliferum-A case report

Hidradenoma papilliferum (HP) is a benign adnexal neoplasm of the vulva that typically presents as a unilateral, flesh-colored papule in the labium majus in middle-aged Caucasian women. It is considered to be a close counterpart of the intraductal papilloma of the breast. Malignant transformation is rare with few reports in the literature. We present a case of vulvar mammary-type apocrine hidradenocarcinoma arising in an HP.

Risk Factors for Keratinocyte Carcinoma in Recipients of Allogeneic Hematopoietic Cell Transplants

Importance

Allogeneic hematopoietic cell transplant (alloHCT) is known to increase the risk for keratinocyte carcinoma. The extent to which host characteristics, including pigmentary phenotype and UV radiation exposure, contribute is unknown.

Objective

To identify and validate independent risk factors for keratinocyte carcinoma after alloHCT, including those associated with the transplant and the host.

Design, Setting, and Participants

This retrospective cohort study analyzed a consecutive sample of alloHCT recipients from January 1, 2000, to December 31, 2014, at the Mayo Clinic, Rochester, Minnesota (n = 872) and University Hospitals Cleveland Medical Center, Cleveland, Ohio (n = 147). Participants from the Mayo Clinic were randomly allocated (2:1) into discovery (n = 581) and validation (n = 291) cohorts. Time to first keratinocyte carcinoma and information about transplant- and host-associated risk factors were extracted. A multivariate keratinocyte carcinoma risk model was created using a stepwise Cox proportional hazards regression model with P ≤ .05 for entry that incorporated all covariates that were individually statistically significant at α = 0.05 in the discovery cohort. The risk model was first internally validated using the Mayo Clinic validation cohort and then externally validated using the independent cohort of alloHCT recipients at University Hospitals Cleveland Medical Center. Data were analyzed from March 13, 2018, to June 12, 2019.

Exposures

Allogeneic hematopoietic cell transplant.

Main Outcomes and Measures

The primary outcome was time to development of the first cutaneous keratinocyte carcinoma after alloHCT; secondary outcome, time to development of the first individual basal and/or squamous cell carcinoma after alloHCT.

Results

Of the 872 alloHCT recipients identified in the Mayo Clinic cohort (520 men [59.6%]; mean [SD] age, 48.3 [12.6] years), 95 (10.9%) developed keratinocyte carcinoma after alloHCT during 5349 person-years of follow-up. Of the 147 alloHCT recipients in the exernal validation cohort (86 men [58.5%]; mean [SD] age, 47.9 [17.5] years), 18 (12.2%) developed keratinocyte carcinoma after alloHCT in 880 person-years of follow up. Risk factors independently associated with keratinocyte carcinoma after alloHCT included age (hazard ratio [HR] per 10 years, 1.72; 95% CI, 1.21-2.42), chronic lymphocytic leukemia (HR, 2.47; 95% CI, 1.20-5.09), clinically photodamaged skin (HR, 3.47; 95% CI, 1.87-6.41), and history of cutaneous squamous cell carcinoma (HR, 2.60; 95% CI, 1.41-5.91). Harrell concordance statistics were 0.81 (95% CI, 0.72-0.90) and 0.86 (95% CI, 0.74-0.98) for internal and external validation of the keratinocyte carcinoma risk model, respectively.

Conclusions and Relevance

This study found validated independent risk factors for keratinocyte carcinoma after alloHCT that are enriched with host- compared with transplant-associated risk factors. These findings highlight the importance of assessing host-associated risk factors for keratinocyte carcinoma in patients eligible for alloHCT. Future studies should examine whether keratinocyte carcinoma risk stratification before alloHCT may inform long-term surveillance strategies.

Preemptive analgesia for postoperative pain relief in thoracolumbosacral spine operations: a double-blind, placebo-controlled randomized trial

OBJECTIVEPreemptive administration of analgesic medication is more effective than medication given after the onset of the painful stimulus. The efficacy of preoperative or preemptive pain relief after thoracolumbosacral spine surgery has not been well studied. The present study was a double-blind, placebo-controlled randomized trial of preemptive analgesia with a single-shot epidural injection in adult patients undergoing spine surgery.METHODSNinety-nine adult patients undergoing thoracolumbosacral operations via a posterior approach were randomized to receive a single shot of either epidural placebo (group 1), hydromorphone alone (group 2), or bupivacaine with hydromorphone (group 3) before surgery at the preoperative holding area. The primary outcome was the presence of opioid sparing and rescue time-defined as the time interval from when a patient was extubated to the time pain medication was first demanded during the postoperative period. Secondary outcomes include length of stay at the postanesthesia care unit (PACU), pain score at the PACU, opioid dose, and hospital length of stay.RESULTSOf the 99 patients, 32 were randomized to the epidural placebo group, 33 to the hydromorphone-alone group, and 34 to the bupivacaine with hydromorphone group. No significant difference was seen across the demographics and surgical complexities for all 3 groups. Compared to the control group, opioid sparing was significantly higher in group 2 (57.6% vs 15.6%, p = 0.0007) and group 3 (52.9% vs 15.6%, p = 0.0045) in the first demand of intravenous hydromorphone as a supplemental analgesic medication. Compared to placebo, the rescue time was significantly higher in group 2 (187 minutes vs 51.5 minutes, p = 0.0014) and group 3 (204.5 minutes vs 51. minutes, p = 0.0045). There were no significant differences in secondary outcomes.CONCLUSIONSThe authors' study demonstrated that preemptive analgesia in thoracolumbosacral surgeries can significantly reduce analgesia requirements in the immediate postoperative period as evidenced by reduced request for opioid medication in both analgesia study groups who received a preoperative analgesic epidural. Nonetheless, the lack of differences in pain score and opioid dose at the PACU brings into question the role of preemptive epidural opioids in spine surgery patients. Further work is necessary to investigate the long-term effectiveness of preemptive epidural opioids and their role in pain reduction and patient satisfaction.Clinical trial registration no.: NCT02968862 (clinicaltrials.gov).

The CRISP-Q study: Communicating the risks and benefits of colorectal cancer screening

Background and objectives

Many Australians at average risk of colorectal cancer (CRC) are undergoing unnecessary colonoscopic screening, while many at increased risk are getting inadequate screening. The aim of this study was to test different ways of communicating the risks and benefits of CRC screening, as part of the development of a CRC risk prediction (CRISP) tool.

Method

General practice patients were shown five different risk presentations for hypothetical ‘average’ and ‘increased’ risk cases and were asked to choose the screening method they would undergo. Associations were explored between risk presentation type and ‘risk-appropriate screening’ choice.

Results

All risk formats were associated with improved risk-appropriate screening by participants (n = 204); however, there was a statistical trend favouring absolute risk with a government recommendation and an ‘expected frequency tree’. The icon array was most weakly associated with appropriate screening.

Discussion

This research will inform approaches to communicating risk in CRISP and may be of wider relevance to supporting informed decisions about cancer screening.

Need for additional anesthesia after single injection spinal analgesia for labor: a retrospective cohort study

BACKGROUND

There is little information about the use and efficacy of single injection spinal blocks for labor analgesia; specifically, how frequently subsequent analgesia or anesthesia is needed. This study determined how frequently an additional anesthetic intervention was needed in women who received single injection spinal analgesia.

METHODS

This retrospective study examined electronic medical records to find all single injection spinal analgesic blocks for labor analgesia over a 14-year (2003-2016) period. Patient and block characteristics and patient outcomes were recorded. The primary outcome was need for an additional anesthetic intervention following single injection spinal for labor analgesia.

RESULTS

Four-hundred-and-twenty-eight patients received single injection spinal blocks for labor and 60 (14.0%) needed an additional anesthetic either for labor analgesia (n=49) or an unexpected procedure (n=11). Two of these (0.5%) required general anesthesia. Parity of zero (nulliparous), a low cervical dilation at the time of the spinal injection, and induction of labor status, were associated with an increased risk of needing an additional anesthetic intervention.

CONCLUSIONS

This retrospective review provides evidence that single injection spinal anesthesia may be used for multiparous women with spontaneous labor and more advanced cervical dilation.

Microvascular lining options for subtotal and total nasal reconstruction: A scoping review

BACKGROUND

Restoration of nasal lining is essential in reconstruction of subtotal/total nasal defects. When local flaps are inadequate, a microvascular flap should be used. The purpose of this scoping review is to map the literature and identify the described flap options for subtotal/total nasal reconstruction. Further to that, we will summarize the stated advantages and disadvantages, evaluate functional and esthetic outcomes, and appraise the current body of literature.

METHODS

An electronic literature search was completed. Studies required adult patients with subtotal/total nasal defects and lining reconstruction with microvascular free flap. Two independent reviewers completed screening and data extraction. Flap characteristics, advantages, disadvantages, functional and esthetic outcomes were reviewed. Two independent reviewers evaluated study quality.

RESULTS

Of 305 initial articles, 22 studies were included (13 case reports, 9 case series) accounting for 65 flaps. Microvascular flaps varied by composition and anatomical location. For functional outcome, 13 studies used clinical exam by surgeon, 5 reported patient being satisfied, 3 studies used endoscopy, and 1 study used nasometry. Assessing esthetic outcome, 13 studies used clinical exam by surgeon, 5 studies reported patient being satisfied, 1 study used patient-reported outcome measures, and 16 studies included photos. Study quality (modified CARE and PROCESS checklists) was deemed poor. Quality of available evidence was level IV.

CONCLUSIONS

Microvascular free flaps for nasal reconstruction, confer an overall satisfactory functional and esthetic outcome. All studies lack a systematic and comprehensive approach to assessing and reporting these outcomes. Future research should provide objective assessment and utilize patient reported outcome measures.

Ethanol and/or radiofrequency ablation to treat venolymphatic malformations that manifest as a bulging mass in the head and neck

AIM

To evaluate the efficacy of ultrasound (US)-guided ethanol ablation (EA) and radiofrequency ablation (RFA) for treating venolymphatic malformations (VLM) of the head and neck.

MATERIALS AND METHODS

US-guided EA and/or RFA were performed on 17 patients with VLM of the head and neck. Computed tomography (CT) or magnetic resonance imaging (MRI) was used to locate the cranial nerves and salivary gland ducts that were close to targets, and these were avoided during the procedures. Treatment response was assessed using volume reduction and cosmetic grading scoring.

RESULTS

Nine VLMs were located close to the functional structures: Stensen's duct (n=3), cranial nerve branch (n=3), or both (n=3). All patients demonstrated >50% volume reduction, except one patient with a microcystic lymphatic malformation that was abutting the facial nerve. Median cosmetic grading scores improved from 4 to 1 (p<0.001).

CONCLUSION

US-guided EA and/or RFA are effective and safe treatment methods in patients with VLMs of the head and neck. Treatment selection of EA and/or RFA could be performed based on the composition of VLMs as assessed at CT and MRI.

Activated T cells secrete an alternatively spliced form of common γ-chain that inhibits cytokine signaling and exacerbates inflammation

The common γ-chain (γc) plays a central role in signaling by IL-2 and other γc-dependent cytokines. Here we report that activated T cells produce an alternatively spliced form of γc mRNA that results in protein expression and secretion of the γc extracellular domain. The soluble form of γc (sγc) is present in serum and directly binds to IL-2Rβ and IL-7Rα proteins on T cells to inhibit cytokine signaling and promote inflammation. sγc suppressed IL-7 signaling to impair naive T cell survival during homeostasis and exacerbated Th17-cell-mediated inflammation by inhibiting IL-2 signaling upon T cell activation. Reciprocally, the severity of Th17-cell-mediated inflammatory diseases was markedly diminished in mice lacking sγc. Thus, sγc expression is a naturally occurring immunomodulator that regulates γc cytokine signaling and controls T cell activation and differentiation.

Adjuvant chemotherapy for gastric cancer: a randomised phase 3 trial of mitomycin-C plus either short-term doxifluridine or long-term doxifluridine plus cisplatin after curative D2 gastrectomy (AMC0201)

BACKGROUND

This phase 3 study evaluated the efficacy of new adjuvant chemotherapy (MFP), which intensified the mitomycin-C (MMC) plus short-term doxifluridine (Mf) for gastric cancer.

PATIENTS AND METHODS

A total of 855 patients (424 in Mf, 431 in MFP) with pathological stage II-IV (M0) gastric cancer after D2 gastrectomy were randomly assigned to receive either Mf (MMC 20 mg m(-2), followed by oral doxifluridine 460-600 mg m(-2) per day for 3 months) or MFP (MMC 20 mg m(-2), followed by oral doxifluridine 460-600 mg m(-2) per day for 12 months with 6 monthly infusions of 60 mg m(-2) of cisplatin) chemotherapy.

RESULTS

With a median follow-up of 6.6 years, there was no difference between the two groups in recurrence-free survival (RFS) (5-year RFS 61.1% in Mf and 57.9% in MFP; hazard ratio 1.10 (95% CI 0.89-1.35); P=0.39) and overall survival (OS) (5-year OS 66.5% in Mf and 65.0% in MFP; hazard ratio 1.11 (95% CI 0.89-1.39); P=0.33).

CONCLUSION

Intensification of Mf adjuvant chemotherapy by prolonging the duration of oral fluoropyrimidine and adding cisplatin was safe but not effective to improve the survivals in curatively resected gastric cancer patients.

An in vivo IL-7 requirement for peripheral Foxp3+ regulatory T cell homeostasis

All T cells are dependent on IL-7 for their development and for homeostasis. Foxp3(+) regulatory T cells (Tregs) are unique among T cells in that they are dependent on IL-2. Whether such IL-2 dependency is distinct from or in addition to an IL-7 requirement has been a confounding issue, particularly because of the absence of an adequate experimental system to address this question. In this study, we present a novel in vivo mouse model where IL-2 expression is intact but IL-7 expression was geographically limited to the thymus. Consequently, IL-7 is not available in peripheral tissues. Such mice were generated by introducing a thymocyte-specific IL-7 transgene onto an IL-7 null background. In these mice, T cell development in the thymus, including Foxp3(+) Treg numbers, was completely restored, which correlates with the thymus-specific expression of transgenic IL-7. In peripheral cells, however, IL-7 expression was terminated, which resulted in a general paucity of T cells and a dramatic reduction of Foxp3(+) Treg numbers. Loss of Tregs was further accompanied by a significant reduction in Foxp3(+) expression levels. These data suggest that peripheral IL-7 is not only necessary for Treg survival but also for upregulating Foxp3 expression. Collectively, we assessed the effect of a selective peripheral IL-7 deficiency in the presence of a fully functional thymus, and we document a critical requirement for in vivo IL-7 in T cell maintenance and specifically in Foxp3(+) cell homeostasis.

A non-doped organic light emitting diode with pure red emission using a new host emitter

A red fluorescent material (2E,2'E)-3,3'-[4,4"-bis(dimethylamino)-1,1': 4',1 "-terphenyl-2',5'-diyl]bis[2-(2-thienyl)acrylonitrile] (ABCV-Th) was synthesized for use in organic light emitting diodes (OLEDs) as the host emissive material. It has been reported some green and blue host emissive materials used in OLEDs revealed high device performance but, owing to concentration quenching, comparable red light emitting materials are still rare in OLEDs application. Non-doped organic light emitting diodes, with the structure of ITO/NPB/ABCV-Th (30 nm and 50 nm)/BCP/Alq3/Liq/Al were fabricated using ABCV-Th as the host emitter. The peak wavelength and full width at half maximum (FWHM) of electroluminescence (EL) were 629.5 nm and 68.5 nm, respectively. The maximum brightness and turn on voltage of the device were measured to be 1330 cd/m2 at 14.6 V and 3.4 V, respectively. The device exhibited authentic red emission (Commission Internationale De L'Eclairage (CIE(xy)) = 0.65, 0.34) which is almost close to the standard red (CIE(xy) = 0.67, 0.33) demanded by the national television system committee (NTSC).

Implantable diagnostic device for cancer monitoring

Biopsies provide required information to diagnose cancer but, because of their invasiveness, they are difficult to use for managing cancer therapy. The ability to repeatedly sample the local environment for tumor biomarker, chemotherapeutic agent, and tumor metabolite concentrations could improve early detection of metastasis and personalized therapy. Here we describe an implantable diagnostic device that senses the local in vivo environment. This device, which could be left behind during biopsy, uses a semi-permeable membrane to contain nanoparticle magnetic relaxation switches. A cell line secreting a model cancer biomarker produced ectopic tumors in mice. The transverse relaxation time (T(2)) of devices in tumor-bearing mice was 20+/-10% lower than devices in control mice after 1 day by magnetic resonance imaging (p<0.01). Short term applications for this device are numerous, including verification of successful tumor resection. This may represent the first continuous monitoring device for soluble cancer biomarkers in vivo.

Isolated acute cellular rejection of the liver after simultaneous liver and kidney transplantation: a case report

Simultaneous liver and kidney transplantation (SLKT) is now considered the treatment of choice for patients with concurrent end-stage liver and kidney diseases. Even though the early postoperative mortality rate following SLKT is reported to be high compared to that of liver transplantation alone, the liver graft from the same donor has been argued to induce better kidney graft acceptance as evidenced by a low rate of acute renal rejection episodes. There have been many reports of a low incidence of acute renal rejection following SLKT; however, only a few cases were proven by simultaneous biopsies. The authors experienced a case of biopsy-proven isolated acute cellular rejection of the liver graft following SLKT.

Multi-reservoir device for detecting a soluble cancer biomarker

By combining the sensing capabilities of nanoscale magnetic relaxation switches (MRS) within multi-reservoir structures, a potentially powerful implantable multiplexed sensor has been developed. MRS are magnetic nanoparticles that decrease the transverse relaxation time (T(2)) of water in the presence of an analyte. The switches encased in polydimethylsiloxane (PDMS) devices with polycarbonate membranes (10 nm pores) have demonstrated in vitro sensing of the beta subunit of human chorionic gonadotrophin (hCG-beta), which is elevated in testicular and ovarian cancer. Devices showed transverse relaxation time (T(2)) shortening by magnetic resonance imaging (MRI) when incubated in analyte solutions of 0.5 to 5 microg hCG-beta mL(-1). The decrease in T(2) was between 9% and 27% (compared to control devices) after approximately 28 h. This prototype device is an important first step in developing an implantable sensor for detecting soluble cancer biomarkers in vivo.

Magnetic relaxation switch detection of human chorionic gonadotrophin

Functionalized nanoparticle contrast agents, also known as magnetic relaxation switches (MRS), were prepared to detect protein A and the beta subunit of human chorionic gonadotrophin (hCG-beta). Antibodies were attached to cross-linked iron oxide (CLIO) nanoparticles using standard peptide chemistry. Protein A was used as a simple model analyte, as it is naturally multivalent and can bind multiple CLIO-IgG simultaneously. The addition of PA to CLIO-IgG resulted in transverse relaxation time (T2) shortening compared to a blank control as seen by NMR relaxometry measurements. Analyte-induced aggregation was confirmed by light scattering particle size analysis. A two-particle system was designed to measure hCG-beta, as it is not multivalent and requires conjugation of a matched pair of monoclonal antibodies to CLIO (referred to as C95 and C97). Measurement of hCG-beta is important, as elevated serum levels are associated with malignancies including testicular and ovarian cancers. The addition of hCG-beta to C95 and C97 resulted in T2 shortening with a linear dynamic concentration range of 0.1 to 1 molecules of analyte per nanoparticle. Similar data were obtained for the hCG dimer. Observations with higher stoichiometric ratios of analyte to nanoparticle and increased nanoparticle valency were also made. This method can potentially be adapted to detect other biomarkers in solution.

Resorbable polymer microchips releasing BCNU inhibit tumor growth in the rat 9L flank model

Sustained local delivery of single agents and controlled delivery of multiple chemotherapeutic agents are sought for the treatment of brain cancer. A resorbable, multi-reservoir polymer microchip drug delivery system has been tested against a tumor model. The microchip reservoirs were loaded with 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU). BCNU was more stable at 37 degrees C within the microchip compared to a uniformly impregnated polymeric wafer (70% intact drug vs. 38%, at 48 h). The half-life of the intact free drug in the microchip was 11 days, which is a marked enhancement compared to its half-life in normal saline and 10% ethanol (7 and 10 min, respectively) [P. Tepe, S.J. Hassenbusch, R. Benoit, J.H. Anderson, BCNU stability as a function of ethanol concentration and temperature, J. Neurooncol. 10 (1991) 121-127; P. Kari, W.R. McConnell, J.M. Finkel, D.L. Hill, Distribution of Bratton-Marshall-positive material in mice following intravenous injections of nitrosoureas, Cancer Chemother. Pharmacol. 4 (1980) 243-248]. A syngeneic Fischer 344 9L gliosarcoma rat model was used to study the tumoricidal efficacy of BCNU delivery from the microchip or homogeneous polymer wafer. A dose-dependent decrease in tumor size was found for 0.17, 0.67, and 1.24 mg BCNU-microchips. Tumors treated with 1.24 mg BCNU-microchips showed significant tumor reduction (p=0.001) compared to empty control microchips at two weeks. The treatment showed similar efficacy to a polymer wafer with the same dosage. The microchip reservoir array may enable delivery of multiple drugs with independent release kinetics and formulations.

Dual enteric and respiratory tropisms of winter dysentery bovine coronavirus in calves

Although winter dysentery (WD), which is caused by the bovine coronavirus (BCoV) is characterized by the sudden onset of diarrhea in many adult cattle in a herd, the pathogenesis of the WD-BCoV is not completely understood. In this study, colostrum-deprived calves were experimentally infected with a Korean WD-BCoV strain and examined for viremia, enteric and nasal virus shedding as well as for viral antigen expression and virus-associated lesions in the small and large intestines and the upper and lower respiratory tract from 1 to 8 days after an oral infection. The WD-BCoV-inoculated calves showed gradual villous atrophy in the small intestine and a gradual increase in the crypt depth of the large intestine. The WD-BCoV-infected animals showed epithelial damage in nasal turbinates, trachea and lungs, and interstitial pneumonia. The WD-BCoV antigen was detected in the epithelium of the small and large intestines, nasal turbinates, trachea and lungs. WD-BCoV RNA was detected in the serum from post-inoculation day 3. These results show that the WD-BCoV has dual tropism and induces pathological changes in both the digestive and respiratory tracts of calves. To our knowledge, this is the first detailed report of dual enteric and respiratory tropisms of WD-BCoV in calves. Comprehensive studies of the dual tissue pathogenesis of the BCoV might contribute to an increased understanding of similar pneumoenteric CoV infections in humans.

Chromogenic in situ hybridization analysis of HER-2/neu status in cytological samples of breast carcinoma

The current use of humanized monoclonal antibody trastuzumab for the treatment of patients with metastatic breast cancer has made evaluation of HER-2/neu status an important clinical issue. Chromogenic in situ hybridization (CISH), in which the DNA probe is detected with an immunohistochemistry (IHC)-like peroxidase reaction, has been recently developed for the assessment of HER-2/neu status in formalin-fixed breast cancer specimens. We have applied the technique of dual-colour CISH using HER-2/neu and chromosome 17 centromere probes in 27 cytological smears, and these cytological samples were obtained from scrapings of fresh breast tumours. We also investigated HER-2/neu amplification and protein overexpression in the corresponding surgical tissues by CISH and IHC using the monoclonal antibody CB11. Of the 27 cytological cases, HER-2/neu gene amplification was observed in nine cases that were positive cases (2+ and 3+) for IHC. Among the 13 IHC positive cases (2+ and 3+), four of them showed no gene amplification. Identical results for the CISH technique were obtained in the matched surgical samples. The scrape samples from fresh breast tumour offer a monolayer cell population that is especially suitable for CISH. This study has shown that the cytological smear might be a good alternative for the CISH test.

Rewarding and locomotor-activating effects of direct dopamine receptor agonists are augmented by chronic food restriction in rats

RATIONALE

Previous studies indicate that chronic food restriction augments the rewarding and motor-activating effects of diverse drugs of abuse. The drugs that have so far proved susceptible to the augmenting effect of food restriction all increase synaptic concentrations of dopamine (DA). It is not known whether behavioral effects of selective, direct DA receptor agonists are also subject to the augmenting effect of food restriction.

OBJECTIVES

The first objective of this study was to investigate whether the rewarding and locomotor-activating effects of the D1 agonist, A77636, and the D2 agonist, quinpirole are augmented by chronic food restriction. The second purpose was to investigate whether the augmented rewarding and locomotor-activating effects of d-amphetamine in food-restricted rats are reversed by the D1 antagonist, SCH23390.

METHODS

Rewarding effects of drugs were measured in terms of their ability to lower the threshold for lateral hypothalamic self-stimulation (LHSS) using a rate-frequency method. Locomotor-activating effects were measured in terms of the number of midline crossings exhibited by rats in a shuttle apparatus.

RESULTS

A77636 (1.0 and 2.5 mg/kg, i.p.) produced a greater threshold-lowering effect in food-restricted than ad libitum fed rats but produced variable effects on locomotor activity with no difference between groups. Quinpirole (0.2 and 0.5 mg/kg, i.p.) produced a marginally greater threshold-lowering effect in food-restricted rats and a dramatic locomotor response that was exclusive to food-restricted rats. The D1 antagonist, SCH23390, at a dose of 0.01 mg/kg (i.p.), had no effect on the lowering of LHSS threshold by amphetamine (0.5 mg/kg, i.p.) in ad libitum fed rats but blocked the augmentation otherwise observed in food-restricted rats. SCH23390, at a dose of 0.025 mg/kg, had no effect on locomotor activity induced by amphetamine (0.5 mg/kg) in ad libitum fed rats but blocked the augmentation otherwise observed in food-restricted rats.

CONCLUSIONS

These results indicate that the augmentation of reward by food restriction extends to drugs that bypass the DA terminal and act postsynaptically. When taken together with prior immunohistochemical and behavioral findings, these results suggest that food restriction may increase the "enabling" effect of the D1 receptor on DA-mediated behaviors.

Chronic food restriction in rats augments the central rewarding effect of cocaine and the delta1 opioid agonist, DPDPE, but not the delta2 agonist, deltorphin-II

RATIONALE

Chronic food restriction augments the self-administration and locomotor stimulating effects of opiates, psychostimulants and NMDA antagonists. The extent to which these effects can be attributed to changes in drug pharmacokinetics and bioavailability versus sensitivity of the neuronal circuits that mediate the affected behavioral functions, has not been established. Recent studies point to central adaptive changes insofar as rewarding, locomotor and c-fos-inducing effects of amphetamine and MK-801, injected directly into the lateral ventricle, are greater in food-restricted than ad libitum fed rats. The increased expression of c-fos in nucleus accumbens (NAC) shell, in particular, suggests that food restriction may augment drug reward by modulating dopamine (DA) synaptic function in this area.

OBJECTIVES

The first purpose of this study was to investigate whether the rewarding effects of cocaine and the delta1 opioid agonist DPDPE, both of which increase DA synaptic transmission, are augmented by food restriction. The second purpose was to determine whether the delta2 opioid agonist, deltorphin-II, which has been reported to exert DA-independent rewarding effects, is subject to the potentiating effect of food restriction.

METHODS

Rewarding effects of drugs were measured in terms of their ability to lower the threshold for lateral hypothalamic self-stimulation (LHSS) using a rate-frequency method.

RESULTS

In separate experiments, cocaine (50, 100 and 150 microg, ICV) and DPDPE (10 and 25 microg, ICV) produced greater threshold-lowering effects in food-restricted than ad libitum fed rats. Deltorphin-II (5.0, 10 and 25 microg, ICV) had no effect on reward thresholds, regardless of feeding regimen.

CONCLUSIONS

While the reported DA-independence of deltorphin-II rewarding effects seemed to offer a means of testing the hypothesis that DA transmission is the critical modulated variable in food-restricted subjects, rewarding effects of this compound could not be demonstrated in the LHSS paradigm. The present results do, however, confirm and extend prior findings indicating that the enhanced self-administration of abused drugs by food-restricted subjects is due to enhanced sensitivity of a final common pathway for drug reward.

Annexin I is a stress protein induced by heat, oxidative stress and a sulfhydryl-reactive agent

Annexin I (also called lipocortin 1) is a 37-kDa member of the annexin family of proteins. It has been proposed to be involved in the regulation of cell growth and differentiation, apoptosis, and inflammation. Previously, we have reported that annexin I displays a chaperone-like function (Kim, G.Y., Lee, H.B., Lee, S.O., Rhee, H.J. & Na, D.S. (1997) Biochem. Mol. Biol. Int. 43, 521-528). To determine the possibility that annexin I is a stress protein, we examined whether expression of annexin I and annexin I mRNA increases in response to stresses in A549 and HeLa cells. Treatments of cells with heat, hydrogen peroxide or sodium arsenite resulted in (a) an increase in annexin I and annexin I mRNA and (b) translocation of annexin I from the cytoplasm to the nucleus and perinuclear region. The annexin I gene promoter region, cloned upstream of a reporter gene, was inducible in response to heat, hydrogen peroxide, and sodium arsenite. These results indicate that annexin I serves as a stress protein and annexins may constitute a new class of stress proteins.

Altered cell cycle control at the G(2)/M phases in aryl hydrocarbon receptor-null embryo fibroblast

The aryl hydrocarbon receptor (AHR) is known to mediate the toxic and carcinogenic effects of polycyclic aromatic hydrocarbons and dioxins. High-affinity AHR ligands, such as 2,3,7, 8-tetrachlorodibenzeno-p-dioxin, have been shown to modify cell proliferation and differentiation. However, the mechanisms by which AHR affects cell proliferation and differentiation are not fully understood. To investigate the role of AHR in cell proliferation, mouse embryonic fibroblasts (MEFs) derived from AHR-null mice were obtained and characterized. Compared with wild-type MEFs, AHR-null cells exhibited a lower proliferation rate with an accumulation of 4N DNA content and increased apoptosis. The expression levels of Cdc2 and Plk, two kinases important for G(2)/M phase of cell cycle, were down-regulated in AHR-null MEFs. In contrast, transforming growth factor-beta (TGF-beta), a proliferation inhibitor in several cell lines, was present at high levels in conditioned medium from AHR-null MEFs. Concomitant with G(2)/M cell accumulation, treatment of wild-type MEFs with TGF-beta3 also resulted in down-regulation of both Cdc2 and Plk. Thus, overproduction of TGF-beta in AHR-deficient cells appears to be the primary factor that causes low proliferation rates and increased apoptosis. Taken together, these results suggest that AHR influences TGF-beta production, leading to an alteration in cell cycle control.

Solubilization of biphenyl dimethyl dicarboxylate by cosolvency

Biphenyl dimethyl dicarboxylate (BDD) is a synthetic analogue of schizandrin C, one of the components isolated from Fructus schizandrae, and has been widely prescribed for improvement of liver functions and symptoms of patients with liver disease. However, its oral preparations have been known to have limited bioavailability due to its extremely low solubility in water, and its solubility problem also limits preparation of its parenteral dosage forms. In this research, we searched for solvent systems to solubilize BDD to overcome these problems. The ternary solvent systems of N,N'-dimethylacetamide (DMA)/alcohol/water and Cremophor EL/DMA/alcohol were studied intensively for this purpose. BDD was solubilized effectively in these cosolvents, and the results showed that the cosolvent systems were effective for solubilizing BDD up to the concentration that might be employed for preparation of parenteral dosage forms. Formulation of a BDD concentrate for intravenous infusion was proposed employing the cosolvent system of Cremophor EL/DMA/alcohol.

Reduced expression of tissue inhibitor of metalloproteinase in nodal metastasis of stomach cancer

The matrix metalloproteinases (MMPs) have been associated with tumor cell invasion and metastasis of human cancers by mediating the degradation of extracellular matrix components. Therefore, these enzymes and their inhibitor (TIMP-2) constitute promising targets in the development of anticancer therapies. In order to investigate the correlation between expressions of TIMP-2, MMPs and clinical outcome, immunohistochemical staining of MMP-2, MMP-9, and TIMP-2 were performed on paraffin-embedded tissue sections of 15 early gastric cancers (EGC) and 15 advanced gastric carcinomas (AGC) without nodal metastasis and 15 AGC with nodal metastasis (AGCn+). MMP-2 and MMP-9 were expressed in neoplastic cell plasma membrane in 83.3% and 88% of cases of AGC, respectively with inter-tumoral variability of staining intensity. MMP-2 and MMP-9 staining were not correlated with presence of nodal metastasis or degree of invasion depth at the time of diagnosis (p>0.05). The immunoreactivity of TIMP-2 was detected in the peri-tumoral stroma. Residual benign stomach tissue showed no or weak immunoreactivity for TIMP-2 staining. Among AGC, neoplasms with diffuse and strong TIMP-2 staining have less frequent metastasis (28.6%) than cases with focal and weak (68.8%) (p<0.05). Early gastric cancer revealed diffuse and strong TIMP-2 expressions. We conclude that clinical outcome such as depth of invasion or metastasis is more closely related to the expression of TIMP-2 than the corresponding MMPs.

Chaperone-like function of lipocortin 1

Lipocortin 1 (LC1) is a 37 kDa member of the annexin family of proteins. It has been proposed to act as a mediator of some of the actions of glucocorticoids in anti-inflammatory and immune suppressive functions. LC1 has been shown to play a role in cell proliferation, apoptosis, and differentiation. However, the exact biological functions of LC1 still remain obscure. Here it is shown that LC1 displays a chaperone-like function. Stoichiometric amounts of LC1 suppressed thermally induced inactivation and aggregation of the test enzymes citrate synthase and glutamate dehydrogenase. LC1 was also effective in refolding guanine hydrochloride-denatured glutamate dehydrogenase, as judged by circular dichroism spectroscopy.

Purification and characterization of novel heparin-binding growth factors in uterine secretory fluids. Identification as heparin-regulated Mr 10,000 forms of connective tissue growth factor

Uterine growth factors are potential effector molecules in embryo growth signaling pathways. Pig uterine luminal flushings contained a heparin-binding growth factor (HBGF) that required 0.8 M NaCl for elution from heparin columns and was termed HBGF-0.8. This factor, which was heat- and acid-labile and of Mr 10,000 as assessed by gel filtration, stimulated DNA synthesis in fibroblasts and smooth muscle cells but not endothelial cells. Two forms of HBGF-0.8, termed HBGF-0.8-P1 and HBGF-0.8-P2, exhibited differential heparin-binding properties. SDS-polyacrylamide gel electrophoresis showed that each form of HBGF-0.8 migrated with an apparent Mr of 10, 000 under reducing conditions. Amino acid sequencing revealed the N-terminal sequence EENIKKGKKXIRTPKI for HBGF-0.8-P1 and ENIKKGKKXIRT for HBGF-0.8-P2. These sequences corresponded, respectively, to residues 247-262 and 248-259 of the 349-residue predicted primary translation product of porcine connective tissue growth factor (pCTGF). 10-kDa CTGF-mediated fibroblast DNA synthesis was modulated by exogenous heparin, and CTGF-immunoreactive proteins of 10, 16, and 20 kDa were present in unfractionated uterine luminal flushings. These data reveal the identity of a novel growth factor in uterine fluids as a highly truncated form of CTGF and show that the N-terminal two-thirds of the CTGF primary translation product is not required for mitogenic activity or heparin binding.

Inhibition of neointimal proliferation of rat carotid artery by sulodexide

Sulodexide, a glycosaminoglycan-containing compound, is known to have an antiproliferative effect on vascular smooth-muscle cells, in vitro, as well as antithrombotic and fibrinolytic effects. But there are few reports about the effect of neointimal proliferation in vivo. In this study, we examined whether Sulodexide was effective in the inhibition of neointimal proliferation after vascular injury. Ten-week-old Sprague-Dawley rats were subjected to vascular injury by endothelial denudation of the common carotid artery by using a balloon catheter. They were then allocated randomly into a control group (saline 2 ml for 3 days, and then 1 ml for 18 days, IM) and a treated group (Sulodexide 10 mg/kg/day for 3 days, and then 4 mg/kg/day for 18 days, IM). Three weeks after vascular injury, we analyzed the neointimal proliferation using morphometry. The neointimal proliferation was significantly reduced in the treated group compared to the control group (Ratio of neointimal area to medial area; 118.39 +/- 6.80% in the treated group, 177.25 +/- 17.25% in the control group). This result showed that Sulodexide might be effective in reducing the rate of restenosis after balloon angioplasty.

High molecular mass forms of epidermal growth factor in pig uterine secretions

Accumulating evidence suggests that uterine luminal fluids contain a variety of polypeptide growth factors and cytokines that, it is speculated, have roles in the development, growth and differentiation of the uterus and, during pregnancy, in the growth and survival of the embryo. Although epidermal growth factor (EGF) has previously been identified by radioimmunoassay and immunohistochemistry in the pig uterus, there have been no detailed studies of the secreted EGF protein. EGF was therefore purified from uterine flushings and uterine fluids of nonpregnant pigs of mixed breed using a variety of ion-exchange chromatography steps. Uterine flushings and fluids contained an anionic factor(s) that at 4 degrees C competed with 125I-labelled mouse EGF for binding to EGF receptors on an endometrial carcinoma cell line and stimulated DNA synthesis in Balb/c mouse 3T3 fibroblasts. As analysed by gel filtration, uterine fluids contained a 3-6 kDa factor that stimulated 3T3 cell DNA synthesis and was a competitor of cellular 125I-labelled EGF binding. Gel filtration further revealed that uterine flushings and fluids contained, respectively, 45 kDa and 40-70 kDa moieties that were mitogenic and that bound to the EGF receptor. SDS-PAGE and western blotting using an antiserum specific for pig EGF revealed immunoreactive forms of EGF of approximately 25 kDa in partially purified uterine flushings. It is concluded that uterine secretory EGF occurs, at least in part, as high molecular mass proteins. The ability of these high molecular mass EGFs to bind to and activate the EGF receptor suggests that they may be authentic ligands for the EGF receptor in utero.

Pig uterine luminal fluid contains the developmentally regulated neurotrophic factor, pleiotrophin

The pig conceptus produces a non-invasive placenta which is probably dependent on uterine secretory products during both the pre- and post-attachment periods. Since some of these factors are also produced during the oestrous cycle, uterine luminal flushings (ULF) from adult nonpregnant pigs were analysed to identify potentially important maternally-secreted growth factors or cytokines. ULF contained several proteins that were detected on Western blots by an antibody raised against the N-terminal 14 amino acids of rat pleiotrophin (PTN). One of the proteins co-migrated on SDS-PAGE gels and co-eluted from heparin-affinity columns with 18 kDa recombinant human PTN, suggesting its identity as the intact native porcine PTN (pPTN) molecule. Additional immunoreactive forms of pPTN were identified that were of lower molecular mass (14-16 kDa), had lower heparin-affinities, were more hydrophobic, and were apparently C-terminally truncated. Native pPTN was isolated from ULF using cation-exchange chromatography, heparin-affinity fast protein liquid chromatography and C4 reverse-phase high performance liquid chromatography. Structural analysis of the purified protein resulted in definitive identification of 15 out of 17 N-terminal amino acids; these were 100% conserved with the corresponding residues of human, bovine and rat PTN. These results demonstrate various biochemical properties of pPTN and suggest that, in addition to the apparent involvement of PTN in differentiation during early neonatal life, it may be delivered in uterine secretory fluids to, as yet, undefined target cells in the reproductive tract of the adult female.

Purification of heparin-binding epidermal growth factor-like growth factor from pig uterine luminal flushings, and its production by endometrial tissues

Pig uterine luminal flushings contain at least four heparin-binding growth factors (HBGF) that stimulate fibroblast [3H]thymidine incorporation. One of these factors, which appeared to be a relatively minor HBGF, was eluted from heparin affinity columns by 1.0 M NaCl and was found to compete with 125I-epidermal growth factor (EGF) for binding to an endometrial carcinoma cell line. This EGF receptor (EGF-R)-binding property was abolished by an antiserum to heparin-binding EGF-like growth factor (HB-EGF) that specifically blocks binding of HB-EGF to the EGF-R. Reverse-phase HPLC resulted in the purification of two EGF-R-binding activities correlated with 13,500 and 17,000 M(r) proteins that reacted with an antiserum raised against residues 9-26 of human HB-EGF. Uterine extracts also contained an EGF-R-binding factor that was eluted from heparin by 1.0 M NaCl and was antagonized by HB-EGF antiserum. Endometrial mRNA subjected to reverse transcriptase-polymerase chain reaction (RT-PCR) and nested PCR through the use of HB-EGF-specific primers yielded fragments of the predicted size. Cloning of the nested PCR product revealed a 380-bp porcine HB-EGF cDNA sequence that was 78-85% homologous to primate or rodent HB-EGF. HB-EGF was immunohistochemically localized primarily to the luminal epithelium in both pregnant and nonpregnant animals.

Differential effects of transforming growth factor-beta 1 and bone morphogenetic proteins in cultured rat osteogenic sarcoma and mink lung epithelial cells

The effects of porcine bone morphogenetic protein (BMP) on DNA and collagen synthesis in cultured rat osteogenic sarcoma cells and mink lung epithelial cells were studied and compared with the effects induced by transforming growth factor-beta 1 (TGF-beta 1). In both cells, DNA synthesis was slightly but significantly increased by BMP whereas it was notably decreased by TGF-beta 1. The inhibitory action of TGF-beta 1 overrode the activation of DNA synthesis by BMP when the cells were incubated together with TGF-beta 1 and BMP. In osteogenic sarcoma cells, collagen synthesis was enhanced by both BMP and TGF-beta 1, but the stimulatory action of BMP was weaker than that of TGF-beta 1. In epithelial cells, TGF-beta 1 increased collagen synthesis but BMP induced no significant changes. No synergistic effects of TGF-beta 1 and BMP on collagen synthesis were observed in both cells. The present study demonstrates the possibility of direct actions of BMP and TGF-beta 1 on cultured rat osteogenic sarcoma cells and mink lung epithelial cells in vitro.

Kinetics and mechanism of an NADPH-dependent succinic semialdehyde reductase from bovine brain

An NADPH-dependent succinic semialdehyde reductase has been purified from bovine brain by several chromatographic procedures. The preparation appeared homogeneous on SDS/PAGE. The enzyme is a monomeric protein with a molecular mass of 28 kDa. A number of properties of the bovine brain enzyme, such as substrate specificity, specific activity, molecular mass, optimum pH, amino acid composition, and kinetic parameters, have been determined and compared with those reported for preparations from other sources. The results indicate that the enzyme isolated from bovine brain in the present study is different from those reported for preparations from other sources. The inhibition kinetic patterns obtained when the products of the reaction or substrate analogs are used as inhibitor of the reaction catalyzed by the enzyme are consistent with an ordered sequential mechanism involving the formation of an intermediate ternary complex and in which NADPH is the first substrate to bind the enzyme.

Interaction of heparin-binding EGF-like growth factor (HB-EGF) with the epidermal growth factor receptor: modulation by heparin, heparinase, or synthetic heparin-binding HB-EGF fragments

The binding of heparin-binding EGF-like growth factor (HB-EGF) to the epidermal growth factor (EGF) receptor of human endometrial carcinoma cells was compared to that of EGF using an 125I-EGF radioreceptor assay. The inhibitory effect of HB-EGF on 125I-EGF binding was reversed either in the presence of heparin (but not by chondroitin sulfate) or by pre-treating the cells with heparinase. These treatments did not affect the binding of EGF to its receptor. To map potential regions in the HB-EGF molecule that mediate its heparin-dependent interaction with the EGF receptor, HB-EGF peptides were synthesized that were non-homologous to EGF. Accordingly residues 20-25 and 36-41, but not residues 8-19, of HB-EGF were found to be (i) heparin-binding and (ii) modulators of HB-EGF (but not of EGF) binding to the EGF receptor.

Aluminum interrupts the formation of alkaline-ribonuclease-inhibitor complex from bovine brain

The effect of aluminum on alkaline ribonuclease (RNase) and RNase inhibitor, purified from bovine brain, was investigated. Incubation of alkaline RNase with aluminum interrupted binding of RNase inhibitor to alkaline RNase. A stoichiometry of 1:1 for the binding of aluminum to brain alkaline RNase was estimated, whereas no aluminum was found to be bound to the RNase inhibitor. Aluminum-bound alkaline RNase, however, retained a full alkaline RNase activity. None of the enzyme-bound aluminum was dissociated by dialysis against 50 mM Hepes, pH 7.0, at 4 degrees C for 24 h. Citrate, EDTA, NaF and apotransferrin protected the alkaline RNase against aluminum binding. Aluminum did not bind to the incubated alkaline RNase-inhibitor complex, suggesting that aluminum might compete with RNase inhibitor for the binding site. However, the data from chemical modification and spectroscopic studies indicate that it is also highly possible that aluminum binding to the enzyme induces conformational changes at or near the inhibitor-binding site, which subsequently interrupt binding of RNase inhibitor to alkaline RNase. These results suggest that accumulation of aluminum in brain might affect the regulation of RNA metabolism.

Activation of acid ribonuclease from bovine brain by aluminum

An acid ribonuclease (optimum pH 6.0) has been purified from bovine brain in a five-step procedure. The preparation appeared homogeneous on SDS-polyacrylamide gel electrophoresis. The molecular size of the acid ribonuclease is 70 kDa and it is a dimeric protein with a subunit molecular size of 35 kDa. The acid RNase was activated by aluminum at low concentration. Preincubation of the acid RNase with 10 microM increased the specific activity of the enzyme 2.3-fold at acid pH, while the effect of aluminum was much weaker at alkaline pH under otherwise the same conditions. A stoichiometry of 1: 1 for the binding aluminum to brain acid RNase was estimated. None of the enzyme-bound aluminum was dissociated by dialysis against 50 mM HEPES, pH 7.0 at 4 degrees C for 24 h. Citrate, EDTA, NaF, and apotransferrin abolished the effects of aluminum on the enzyme. Ribonucleic acid also protected the enzyme against the activation caused by aluminum. These results suggest that accumulation of aluminum in brain may change the regulation of ribonucleic acid metabolism.

HLA and Graves' disease in Koreans

The HLA-A, B, C and DR antigen distribution in 128 Korean patients with Graves' disease was compared with that in 220 controls. The frequency of HLA-B13, DR5 and DRw8 (relative risk 3.8, 4.4, and 2.3, respectively) was significantly increased in patients with Graves' disease. There was no significant correlation between the presence of these HLA antigens and the clinical features.