Clinical Decision Support System for Guidelines-Based Treatment of Gonococcal Infections, Screening for HIV, and Prescription of Pre-Exposure Prophylaxis: Design and Implementation Study

BACKGROUND

The syndemic nature of gonococcal infections and HIV provides an opportunity to develop a synergistic intervention tool that could address the need for adequate treatment for gonorrhea, screen for HIV infections, and offer pre-exposure prophylaxis (PrEP) for persons who meet the criteria. By leveraging information available on electronic health records, a clinical decision support (CDS) system tool could fulfill this need and improve adherence to Centers for Disease Control and Prevention (CDC) treatment and screening guidelines for gonorrhea, HIV, and PrEP.

OBJECTIVE

The goal of this study was to translate portions of CDC treatment guidelines for gonorrhea and relevant portions of HIV screening and prescribing PrEP that stem from a diagnosis of gonorrhea as an electronic health record-based CDS intervention. We also assessed whether this CDS solution worked in real-world clinic.

METHODS

We developed 4 tools for this CDS intervention: a form for capturing sexual history information (SmartForm), rule-based alerts (best practice advisory), an enhanced sexually transmitted infection (STI) order set (SmartSet), and a documentation template (SmartText). A mixed methods pre-post design was used to measure the feasibility, use, and usability of the CDS solution. The study period was 12 weeks with a baseline patient sample of 12 weeks immediately prior to the intervention period for comparison. While the entire clinic had access to the CDS solution, we focused on a subset of clinicians who frequently engage in the screening and treatment of STIs within the clinical site under the name "X-Clinic." We measured the use of the CDS solution within the population of patients who had either a confirmed gonococcal infection or an STI-related chief complaint. We conducted 4 midpoint surveys and 3 key informant interviews to quantify perception and impact of the CDS solution and solicit suggestions for potential future enhancements. The findings from qualitative data were determined using a combination of explorative and comparative analysis. Statistical analysis was conducted to compare the differences between patient populations in the baseline and intervention periods.

RESULTS

Within the X-Clinic, the CDS alerted clinicians (as a best practice advisory) in one-tenth (348/3451, 10.08%) of clinical encounters. These 348 encounters represented 300 patients; SmartForms were opened for half of these patients (157/300, 52.33%) and was completed for most for them (147/300, 89.81%). STI test orders (SmartSet) were initiated by clinical providers in half of those patients (162/300, 54%). HIV screening was performed during about half of those patient encounters (191/348, 54.89%).

CONCLUSIONS

We successfully built and implemented multiple CDC treatment and screening guidelines into a single cohesive CDS solution. The CDS solution was integrated into the clinical workflow and had a high rate of use.

Multi-Institutional Phase II Trial Using Dose Escalated Five Fraction Stereotactic Partial Breast Irradiation (S-PBI) with GammaPodTM for Early-Stage Breast Cancer

PURPOSE/OBJECTIVE(S)

We report on our early experience of a multi-institutional phase II study of dose escalated five fraction stereotactic partial breast irradiation (S-PBI) for early-stage breast cancer after partial mastectomy using the GammaPodTM stereotactic radiation system.

MATERIALS/METHODS

Patient eligibility included DCIS or invasive epithelial histologies, AJCC clinical stage 0, I, or II with tumor size < 3 cm, and negative margins. Prior safety of Phase I dose escalation has been reported. Dose was 40 Gy delivered in 5 fractions to the CTV, and minimum dose 30 Gy in 5 fractions to the PTV. CTV margin was 1 cm and PTV margin 3 mm. For PTV cavities larger than 100cc, dose was reduced to 35Gy in 5 fractions to the CTV and 30 Gy in 5 fractions to the PTV. Primary endpoint of the study is to determine the 3-year patient global cosmesis score (4-point scale excellent, good, fair, or poor) and adverse cosmesis using a dose escalated approach with smaller PTV margins than conventional methods. Both patients and physicians completed baseline and subsequent cosmesis outcome questionnaires. Treatment related toxicity was graded using the NCI version 4.0 and RTOG/EORTC late radiation scale.

RESULTS

From 3/2019-10/2021, 74 patients were treated respectively. Of these, 38 were treated to 40Gy and 36 were treated to 35 Gy. Median follow up (f/u) was 24 months (mo), range (r) 3-39mo. Median age was 63 years (r 43-77). Histology included 28 DCIS, and 46 invasive carcinomas. 45/46 invasive tumors were ER+. 60/74 (81%) patients received endocrine therapy, and 7/74 patient received chemotherapy. There were 221 acute grade 1 toxicities, and 28 Grade 2 toxicities. No grade 3 or higher acute toxicities were reported (< 90 days). The most common Grade 2 toxicities were radiation dermatitis (10), breast pain (8), blister (4), skin infection (2), nipple discharge (2), and fatigue (2). In the late period, there were 54 Grade 1 late toxicities, 4 Grade 2 late toxicities, and no Grade 3 or higher late toxicities. Grade 2 toxicities included fibrosis (2), and pain (2). Two patients developed grade 1 asymptomatic nonpalpable fat necrosis both diagnosed at 12 months after radiation treatments. The most common grade 1 late toxicities were breast pain (14), hyperpigmentation (8), fibrosis (10), and fatigue (5). Physicians scored cosmesis excellent or good 70/73 (95.8%), 58/60 (96.7%), 36/36 (100%),17/17(100%) respectively at baseline, 12 months, 24 months, and 36months post SBRT, while patients scored the same periods 62/71 (83.7%), 53/59 (89.8%), 33/36 (91.6%), 17/18 (94.4%). There have been no reports of disease recurrences.

CONCLUSION

Results at 24-month median follow-up, of our dose escalated stereotactic partial breast 5 fraction regimen, has low acute and late toxicity, while maintaining high proportion of excellent/good cosmetic outcomes. Continued analysis of all cohorts is in progress.

CLINICAL TRIALS

gov identifier is NCT03581136.

Financial Toxicity and Patient Experience Outcomes on a Multi-Institutional Phase I Single Fraction Stereotactic Partial Breast Irradiation Protocol for Early-Stage Breast Cancer

PURPOSE/OBJECTIVE(S)

Given the demonstrated financial toxicity (FT) of radiation treatment on breast cancer patients shown in both conventional and our recent 5 fraction stereotactic APBI (S-PBI) study, we assessed the FT, as well as patient-reported utility, quality-of-life and patient experience measures, on patients treated in our phase I single fraction S-PBI trial.

MATERIALS/METHODS

A phase I single fraction dose escalation trial of S-PBI for early-stage breast cancer was conducted. Women with in-situ or stage I-II (AJCC 6) invasive breast cancer following breast conserving surgery were treated with S-PBI in 1 fraction to a total dose of 22.5, 26.5 or 30 Gy (Clinical trials.gov ID NCT02685332). At one month follow-up, patients were asked to complete our novel "Patient Perspective Cost and Convenience of Care Questionnaire". Patients also completed the EQ-5D-5L, including the visual analogue scale of overall health (VAS), at enrollment, 6, 12-, 24-, 36-, and 48-month follow-up.

RESULTS

Of 29 patients enrolled and treated, questionnaire data was available for all patients. Our trial encompassed a wide range of annual household incomes, education, and employment status. Overall, 44.8% (n = 13/29) of patients reported that radiation treatment presented a financial burden. Interestingly, no demographic information, such as patient race, marital status, education, household income, or employment during treatment predicted perceived FT. Patients reporting FT trended towards younger age (median 64 vs 70.5) and having a cancer related co-pay similar to our 5 fraction S-PBI FT trial; however, due to the small size of this study, this did not reach significance (p = 0.24 and 0.10, respectively). VAS and utility scores were calculated per the EQ-5D-5L and remained unchanged from baseline through 4-year follow-up. Likewise, there was no difference in the utility or VAS between patients who reported FT and those who did not. Interestingly, while patient reported cosmesis was similar for all patients at enrollment, patients who reported FT noted significantly worse cosmesis scores (fair/poor vs good/excellent) at 6 month and 2-year follow-ups (p = 0.01 and 0.04, respectively). Finally, patients were surveyed on treatment related disruption to their daily activities and enjoyment of life. The median values were 0 (scale 0-10, with 0 being no disruption) regardless of perceived FT. Patients were also uniformly satisfied with treatment time with a median score of 10 (scale 0-10, 10 being most satisfied).

CONCLUSION

Here, we show that despite using SPBI in a single fraction, nearly half of the patients treated still reported FT of treatment. Importantly, single fraction S-PBI has no negative impact on patient VAS or utility scores, and all patients were uniformly satisfied with treatment time without significant disruption to their life.

Poly-4-hydroxybutyrate (Phasix™) mesh onlay in complex abdominal wall repair

BACKGROUND

Poly-4-hydroxybutyric acid (P4HB, Phasix™) is a biosynthetic polymer that degrades by hydrolysis that can be woven into a mesh for use in soft tissue reinforcement. Herein, we describe our initial experience performing complex abdominal wall repair (CAWR) utilizing component separation and P4HB mesh as onlay reinforcement.

METHODS

All patients undergoing CAWR between June 2014 and May 2017 were followed prospectively for postoperative outcomes. Only those patients who underwent components separation with primary repair of the fascial edges followed by onlay of P4HB mesh were included in this study.

RESULTS

105 patients (52 male, 53 female; mean age 59.2 years, range 22-84) met inclusion criteria. Mean BMI was 29.1 (range 16-48); 52% patients had prior attempted hernia repair, most with multiple medical comorbidities (71% of patients with ASA 3 or greater). 30% of cases were not clean at the time of repair (CDC class 2 or greater). Median follow-up was 36 months (range 9-63). Eighteen patients (17%) developed a hernia recurrence ranging from 2 to 36 months postoperatively. Five (5%) patients developed a localized superficial infection treated with antibiotics, three (2.8%) required re-operation for non-healing wounds, and six (6%) patients developed seroma.

CONCLUSIONS

These data demonstrate a relatively low rate of hernia recurrence, seroma, and other common complications of CAWR in a highly morbid patient population. Importantly, the rate of mesh infection was low and no patients required complete mesh removal, even when placed into a contaminated or infected surgical field.

The Need for Artificial Intelligence in Digital Therapeutics

Digital therapeutics is a newly described concept in healthcare which is proposed to change patient behavior and treat medical conditions using a variety of digital technologies. However, the term is rarely defined with criteria that make it distinct from simply digitizedversions of traditional therapeutics. Our objective is to describe a more valuable characteristic of digital therapeutics, which is distinct from traditional medicine or therapy: that is, the utilization of artificial intelligence and machine learning systems to monitor and predict individual patient symptom data in an adaptive clinical feedback loop via digital biomarkers to provide a precision medicine approach to healthcare. Artificial intelligence platforms can learn and predict effective interventions for individuals using a multitude of personal variables to provide a customized and more tailored therapy regimen. Digital therapeutics coupled with artificial intelligence and machine learning also allows more effective clinical observations and management at the population level for various health conditions and cohorts. This vital differentiation of digital therapeutics compared to other forms of therapeutics enables a more personalized form of healthcare that actively adapts to patients' individual clinical needs, goals, and lifestyles. Importantly, these characteristics are what needs to be emphasized to patients, physicians, and policy makers to advance the entire field of digital healthcare.

Apocrine adenocarcinoma in the setting of apocrine hidrocystoma of the leg

Apocrine hidrocystoma is a benign, cystic lesion often presenting in the periorbital region. Apocrine adenocarcinoma is the rare, malignant counterpart occurring mainly in the axilla and anogenital region. There is a paucity of literature on both entities and co-occurrence has been reported in only 5 cases. We present the case of a 48-year-old man with a history of total body irradiation for chronic myelocytic leukemia, diabetes mellitus, and obesity who presented with a calf mass of two years' duration. Epidermal inclusion cyst was presumed and excisional biopsy was carried out. Pathologic analysis revealed apocrine adenocarcinoma in the setting of a precursor apocrine hidrocystoma. Our patient's unique altered immunity and the direct effects of irradiation on the local microenvironment may have resulted in his rare presentation of co-occurrence of apocrine adenocarcinoma within an existing apocrine hidrocystoma. To our knowledge, our patient is the first reported patient with this presentation in the lower extremity.

Observation method identifies that a lack of canonical babbling can indicate future speech and language problems

AIM

We investigated how accurate observations of canonical babbling (CB) were and explored predictive babbling measures in children with and without medical diagnoses of conditions that can lead to speech and language problems.

METHODS

From 2012 to 2014 this Stockholm-based study recruited 38 children aged nine months to 21 months with medical diagnoses and 30 children aged 10 months without diagnoses and included 21 previously studied 12-month-old children without medical diagnoses. CB and consonant sound production were directly observed by video recording natural play with a caregiver. The percentage of CB was calculated from each recording, and a validated observation form was used. How accurately the children with and without CB were classified was investigated with sensitivity and specificity. The groups were compared using predictive babbling variables.

RESULTS

The observation method identified children with and without CB well, with a specificity of 0.89 and sensitivity of 0.93, respectively. Children with predictive babbling measures were identified in the clinical group (specificity 0.93-0.97), and a lack of these measures indicated a risk of being in the clinical group (odds ratios > 10). The sensitivity was low (0.32-0.42).

CONCLUSION

Observation effectively identified a lack of CB and supported the importance of assessing babbling measures.

Phase I Study of Epigenetic Priming with Azacitidine Prior to Standard Neoadjuvant Chemotherapy for Patients with Resectable Gastric and Esophageal Adenocarcinoma: Evidence of Tumor Hypomethylation as an Indicator of Major Histopathologic Response

Purpose: Epigenetic silencing of tumor suppressor genes (TSG) is an acquired abnormality observed in cancer and is prototypically linked to DNA methylation. We postulated that pretreatment (priming) with 5-azacitidine would increase the efficacy of chemotherapy by reactivating TSGs. This study was conducted to identify a tolerable dose of 5-azacitidine prior to EOX (epirubicin, oxaliplatin, capecitabine) neoadjuvant chemotherapy in patients with locally advanced esophageal/gastric adenocarcinoma (EGC).Experimental Design: Eligible patients had untreated, locally advanced, resectable EGC, ECOG 0-2, and adequate organ function. 5-Azacitidine (V, 75 mg/m²) was given subcutaneously for 3 (dose level, DL 1) or 5 (DL 2) days prior to each 21-day cycle of EOX (E, 50 mg/m²; O, 130 mg/m²; X, 625 mg/m² twice daily for 21 days). Standard 3+3 methodology guided V dose escalation. DNA methylation at control and biomarker regions was measured by digital droplet, bisulfite qPCR in tumor samples collected at baseline and at resection.Results: All subjects underwent complete resection of residual tumor (R0). Three of the 12 patients (25%) achieved a surgical complete response and 5 had partial responses. The overall response rate was 67%. The most common toxicities were gastrointestinal and hematologic. Hypomethylation of biomarker genes was observed at all dose levels and trended with therapeutic response.Conclusions: Neoadjuvant VEOX was well-tolerated with significant clinical and epigenetic responses, with preliminary evidence that priming with V prior to chemotherapy may augment chemotherapy efficacy. The recommended phase II trial schedule is 5-azacitidine 75 mg/m² for 5 days followed by EOX chemotherapy every 21 days. Clin Cancer Res; 23(11); 2673-80. ©2016 AACR.

A large multicenter study of recurrence after surgical resection of branch-duct intraductal papillary mucinous neoplasm of the pancreas

BACKGROUND

Surgery for pancreatic branch-duct intraductal papillary mucinous neoplasm (BD-IPMN) is indicated for therapy of symptomatic patients and to prevent development of invasive cancer. There is currently no consensus on management of BD-IPMN patients after surgical resection. The aim of this retrospective multicenter study was to determine the recurrence and long-term survival after surgical resection of BD-IPMN and to determine the predictive factors of recurrence.

METHODS

All patients who underwent surgery for BD-IPMN from 2005 to 2011 at 2 centers were identified. The diagnosis of BD-IPMN was based upon imaging and endosonographic analysis, and was confirmed by pathological analysis. The lesions were classified into 4 categories according to the WHO classification. Data on cyst characteristics, operative procedure, recurrence, and follow-up were evaluated. Recurrence was defined as the presence of BD-IPMN or mass in the remnant pancreas after surgery as seen on follow-up imaging. Recurrence suspected on imaging was confirmed via histological analysis when possible.

RESULTS

A number of 271 patients (67% female; mean age 63.4 yrs) with BD-IPMN underwent surgical resection. The mean size of the cyst was 24.2mm (range, 12-80). There were 34 (12.5%) patients with an associated mass. 82 (30.3%) patients had worrisome features in the cyst on pre-operative EUS, included mural nodules (N.=25), solid component (N.=27), debris (N.=25), and a dilated major pancreatic duct (N.=5). 144(53%) patients had a pancreaticoduodenectomy for head lesions, 125 (46%) had distal pancreatectomy for tail/body lesions, and 1 (1%) underwent a total pancreatectomy. Histology showed 86% with noninvasive IPMN (adenoma 31%, moderate dysplasia 24%, severe dysplasia or carcinoma in situ 31%) and 14% with invasive IPMN. The mean patient follow-up was 28 months (range, 10-180 months). Recurrence in the remnant pancreas occurred in 34 (12.5%) patients. Of the patients with recurrence, 3/34 had invasive carcinoma and 31/34 had noninvasive cystic lesions; all patients with invasive carcinoma recurrence were those with a previous invasive IPMN. On MVA, risk factors for cyst recurrence were severe dysplasia/intraductal carcinoma in situ and invasive IPMN even after adjusting for elevated CEA (>193 ng/mL), type of surgery, and cyst size (OR 2.8, 95% CI=1.1-7.3; P=0.028). 3 patients who had invasive IPMN and 1 who had severe dysplasia patient with recurrence died, all because of recurrent cancer, with the mean time from recurrence to death being 36 months.

CONCLUSIONS

The risk of BD-IPMN recurrence after resection depends upon the histological type, with the highest-risk groups being those with severe dysplasia/intraductal carcinoma in situ and invasive IPMN. Even after negative resection margins, the pancreatic remnant still harbors a risk of recurrence which requires long-term surveillance.

Implementation of a Novel Electronic Health Record-Embedded Physician Orders for Life-Sustaining Treatment System

In April 2015, Oregon Health & Science University (OHSU) deployed a web-based, electronic medical record-embedded application created by third party vendor Vynca Inc. to allow real-time education, and completion of Physician Orders for Life Sustaining Treatment (POLST). Forms are automatically linked to the Epic Systems™ electronic health record (EHR) patient header and submitted to a state Registry, improving efficiency, accuracy, and rapid access to and retrieval of these important medical orders. POLST Forms, implemented in Oregon in 1992, are standardized portable medical orders used to document patient treatment goals for end-of-life care. In 2009, Oregon developed the first POLST-only statewide registry with a legislative mandate requiring POLST form signers to register the form unless the patient opts out. The Registry offers 24/7 emergency access to POLST Forms for Emergency Medical Services, Emergency Departments, and Acute Care Units. Because POLST is intended for those nearing end of life, immediate access to these forms at the time of an emergency is critical. Delays in registering a POLST Form may result in unwanted treatment if the paper form is not immediately available. An electronic POLST Form completion system (ePOLST) was implemented to support direct Registry submission. Other benefits of the system include single-sign-on, transmission of HL7 data for patient demographics and other relevant information, elimination of potential errors in form completion using internalized logic, built-in real-time video and text-based education materials for both patients and health care professionals, and mobile linkage for signature capture.

Endoscopic Gallbladder Drainage for Acute Cholecystitis

Background/Aims

Surgery is the mainstay of treatment for cholecystitis. However, gallbladder stenting (GBS) has shown promise in debilitated or high-risk patients. Endoscopic transpapillary GBS and endoscopic ultrasound-guided GBS (EUS-GBS) have been proposed as safe and effective modalities for gallbladder drainage.

Methods

Data from patients with cholecystitis were prospectively collected from August 2004 to May 2013 from two United States academic university hospitals and analyzed retrospectively. The following treatment algorithm was adopted. Endoscopic retrograde cholangiopancreatography (ERCP) with sphincterotomy and cystic duct stenting was initially attempted. If deemed feasible by the endoscopist, EUS-GBS was then pursued.

Results

During the study period, 139 patients underwent endoscopic gallbladder drainage. Among these, drainage was performed in 94 and 45 cases for benign and malignant indications, respectively. Successful endoscopic gallbladder drainage was defined as decompression of the gallbladder without incidence of cholecystitis, and was achieved with ERCP and cystic duct stenting in 117 of 128 cases (91%). Successful endoscopic gallbladder drainage was also achieved with EUS-guided gallbladder drainage using transmural stent placement in 11 of 11 cases (100%). Complications occurred in 11 cases (8%).

Conclusions

Endoscopic gallbladder drainage techniques are safe and efficacious methods for gallbladder decompression in non-surgical patients with comorbidities.

Probe-based confocal laser endomicroscopy in the pancreatic duct provides direct visualization of ductal structures and aids in clinical management

BACKGROUND

Confocal endomicroscopy provides real-time evaluation of various sites and has been used to provide detailed endomicroscopic imaging of the biliary tree. We aimed to evaluate the feasibility and utility of probe-based confocal laser endomicroscopy of the pancreatic duct as compared to cytologic and histologic results in patients with indeterminate pancreatic duct strictures.

METHODS

Retrospective data on patients with indeterminate pancreatic strictures undergoing endoscopic retrograde cholangiopancreatography (ERCP) and confocal endomicroscopy were collected from two tertiary care centres. Real-time confocal endomicroscopy images were obtained during ERCP and immediate interpretation according to the Miami Classification was performed.

RESULTS

18 patients underwent confocal endomicroscopy for evaluation of pancreatic strictures from July 2011 to December 2012. Mean pancreatic duct size was 4.2mm (range 2.2-8mm). Eight cases were interpreted as benign, 4 as malignant, 4 suggestive of intraductal papillary mucinous neoplasms, and 2 appeared normal. Cytology/histopathology for 15/16 cases showed similar results to confocal endomicroscopy interpretation. Kappa coefficient of agreement between cyto/histopathology and confocal endomicroscopy was 0.8 (p=0.0001). Pancreatic confocal endomicroscopy changed management in four patients, changing the type of surgery from total pancreatectomy to whipple.

CONCLUSIONS

Confocal endomicroscopy is effective in assisting with diagnosis of indeterminate pancreatic duct strictures as well as mapping of abnormal pancreatic ducts prior to surgery.

Gastric variceal bleeding due to pancreatitis-induced splenic vein thrombosis

Obscure gastrointestinal bleeding is a common clinical scenario. In the upper gastrointestinal tract, gastric varices can be frequently overlooked on endoscopy, particularly if not suspected or volume depleted. We report a case of suspected gastrointestinal bleeding in a patient with a childhood history of pancreatitis, who also experienced severe epigastric pain while in hospital. After transfer to an academic medical centre, the presence of gastric varices was identified and presumed to be due to splenic vein thrombosis. Pancreatitis is the most common cause of splenic vein thrombosis and accords with the patient's history, even though it occurred many years previously. This case highlights the importance of recognising pancreatitis-induced splenic vein thrombosis as a possible aetiology for upper gastrointestinal bleeding.

Recombinant Ebolavirus antigens from insect cells are potent immunogens inducing cellular and humoral immunity in rodents and non-human primates and provide protection against virus challenge (P4325)

Soluble recombinant Filovirus surface glycoproteins (GP) and matrix proteins (VP24 and VP40) were generated in the Drosophila S2 cell expression system and purified by immunoaffinity chromatography. The immunogenicity of individual recombinant Zaire ebolavirus (ZEBOV) subunits and admixtures with or without adjuvants was evaluated in mice, guinea pigs and macaques. Strong antigen-specific IgG responses were observed, includng Ebola virus neutralization responses. In mice and macaques subunit proteins were shown to elicit cell mediated immunity, as significant B- and T-cell stimulation was observed in immune lymphocytes after antigen re-stimulation. Analysis of secreted cytokines in batch-cultured, antigen-stimulated splenocytes or PBMC’s demonstrated Th1 and Th2 type responses. Vaccine candidates were tested in mice and guinea pigs for direct protection against challenge with species-adapted ZEBOV. All vaccine formulations containing ZEBOV GP were protective in mice and serum transfer from such animals into naïve mice demonstrated that humoral immunity alone can be fully protective. Furthermore, the transfer of immune splenocytes into naïve mice showed that recombinant GP and VP24 subunits elicit functional T cell responses that lead to protection against live virus challenge. In guinea pigs, lead vaccine formulations consistently produced high antibody responses and demonstrated 100% protective efficacy in the ZEBOV challenge model.

H-2 antigen expression: Loss in vitro, restoration in vivo, and correlation with cell-mediated cytotoxicity in a mouse lymphoma cell line

The susceptibility to cell-mediated cytolysis of cells of the recently developed C57BL/Ka(H-2 ( b )) lymphoma cell line, BL/VL(3), was investigated in allogeneic assays with thymus-dependent lymphocytes (T cells). Compared to EL4, the widely used C57BL/6(H-2 ( b )) lymphoma cell line, BL/VL(3) cells were found to be insensitive to T-cell-mediated lysis as detected by the use of(51)Crrelease methods. When used as immunogens in alloreactive combinations with BALB/c(H-2 ( d )) splenocytes as responder cells, BL/VL(3) cells failed to elicit sensitization. Serological tests showed that this cell line had profoundly reduced levels of H-2(b) antigens on its surface. When BL/VL(3) cells were reinjected into C57BL/Ka and BALB/c mice, full recovery of H-2(b) antigen expression at the cell surface was observed in both syngeneic and allogeneic hosts after only 11 days of in vivo growth. Concomitantly, they acquired the ability to induce cytotoxic responses in allogeneic T cells and became susceptible to their lytic activity. The expression of H-2 antigens on the surface of BL/VL(3) cells is a reversibly modulated function that depends on in vivo growth conditions and is lost in vitro in the absence of immunoselective pressure.

Vaccination of endangered Hawaiian geese (Nene, Branta sandvicensis) against West Nile Virus using a protein-based vaccine (WN-80E) (113.7)

While West Nile Virus (WNV) has not yet been reported in Hawaii, eventual introduction appears unavoidable. Nene are endemic, endangered Hawaiian geese, and are susceptible to WNV. The goal of this study is to demonstrate that a vaccine developed against WNV for humans (WN-80E) is also highly immunogenic in Nene, and does not produce adverse biological effects. Six captive, non-breeding Nene were immunized with two 10 µg doses (four weeks apart) of the WN-80E recombinant protein adjuvanted with Montanide ISA720. Two Nene were similarly injected with mock preparation as controls. Blood samples were collected prior to the first dose, at two weeks and six months after the second dose. Detailed observations were noted for 48 hours post injection, followed by daily observations of health status to monitor for adverse biological effects. WNV-specific antibody titers were determined by an endpoint ELISA. An unpaired t-test demonstrated significantly higher geometric mean titers for immunized vs. control groups at two weeks post dose two (4129 and 100, respectively, p = 0.0096) and at 6 months post dose two (246 and 63, respectively, p = 0.0023). No swelling was reported at any time during the study at the site of injection. No serious adverse biological effects were observed directly due to the immunization. The vaccine containing the WN-80E and Montanide ISA720 adjuvant appears to be safe and effective in Nene, and should be considered for widespread use in Hawaii.

Bisphosphonates induce senescence in normal human oral keratinocytes

Bisphosphonate-related osteonecrosis of the jaw (BRONJ) commonly occurs in individuals receiving bisphosphonates (BPs) with clinical manifestations of the exposed necrotic bone. Although defective wound healing of soft tissue is frequently, if not always, observed in BRONJ, the effects of BPs on oral soft tissue or cells remain unknown. To investigate the effects of BPs on cells of oral mucosal tissue, we studied the effect of pamidronate (PAM), one of the BPs most commonly administered to cancer patients, on the phenotypes of normal human oral keratinocytes (NHOK) and fibroblasts (NHOF). When exposed to PAM at 10 µM, NHOK, not NHOF, underwent senescence: NHOK overexpressed senescence-associated β-galactosidase (SA-β-Gal), p16INK4A, IL-6, and IL-8. When exposed to a higher level (50 µM) of PAM, NHOK maintained senescent phenotypes, but NHOF underwent apoptosis. PAM-induced senescence in NHOK is mediated, in part, via geranylgeranylation of the mevalonate pathway. Our in vitro 3D oral mucosal tissue construction studies further demonstrated that PAM induced senescence and impaired re-epithelialization of oral mucosa. Analysis of these data indicates that premature senescence of oral mucosal cells and subsequent defective soft-tissue wound healing might be partly responsible for the development of BRONJ in individuals receiving PAM or other BPs.

The Electrophysiological Organization of the Embryonic Chick Heart

Both intracellular and surface electrodes were employed to record electrical activity from embryonic chick hearts between the ages of 3 and 20 days. Cells from the sinus venosus, sinoatrial (SA) valves, atrium, atrioventricular (AV) ring, and ventricle were localized and characterized on the basis of shape, amplitude, rise time, and duration of transmembrane potentials. The differences in transmembrane potentials from these various regions provided the basis for a hypothesis concerned with the distribution of pacemaker potentiality and one related to the origin of the His-Purkinje system. Action potentials recorded along the entire embryonic AV ring were comparable to those of the adult rabbit AV nodal cells in both configuration and sequence of activation and were thus categorized into three functional regions (AN, N, NH). Histological sections of 7 and 14 day hearts demonstrated muscular continuity between the right atrium and ventricle across the muscular AV valve.

The Spread of Excitation in the Embryonic Chick Heart

The spread of excitation in embryonic chick hearts, ranging in age from 7 to 20 days, was studied with both intracellular and extracellular electrodes. Evidence that the delay in ventricular excitation could be attributed to the cells of the entire atrioventricular (AV) ring was obtained, in part, from sagittal sections of the heart. In the intact preparation, uniform propagation occurred throughout the atrial roof at an apparent conduction velocity of 0.4 to 0.5 meter/sec. Delay of impulse propagation was localized in a very narrow band of tissue which extended across the AV ring. The apparent conduction velocity of this tissue was between 0.003 and 0.005 meter/sec. Both normal and retrograde propagation revealed the spread of conduction across the AV ring to be decremental in nature. This finding was supported by high frequency stimulation experiments which gave rise to AV block localized in the cells of the AV ring. Cardiac rhythmicity and AV transmission were responsive to acetylcholine and norepinephrine in much the same manner as in the adult mammalian heart. The present findings are in support of the hypothesis that the embryonic AV ring is the functional counterpart of the adult AV node.

Cutaneous renocolic fistula associated with diverticulitis

We report a case of a cutaneous renocolic fistula in a patient with staghorn calculus and diverticulitis. The most common origins of renocolic fistula are primary renal diseases including xanthogranulomatous pyelonephritis, trauma, malignancy or tuberculosis. While diverticulitis has rarely been associated with renocolic fistula, previous instances of fistulae have been noted in patients with simultaneous kidney disease. Inflammation resulting from kidney disease may place patients with colonic diverticulitis at higher risk for developing renocolic or cutaneous renocolic fistulas.

Ethylene production from methionine

1. A new reaction is described in which ethylene is formed from the Cu(+)-catalysed breakdown of methionine in phosphate buffer at 30 degrees in air. Some of the other products of the reaction are methionine sulphone, methionine sulphoxide, homocysteic acid, homocystine, acrolein, dimethyl disulphide, methanethiol, ethyl methyl sulphide, methane and ethane. These are considered to be produced in different reaction pathways. 2. Hydrogen peroxide is an intermediate in this reaction and can support ethylene production in the model system in anaerobic atmospheres. Cuprous copper is the active form that catalyses the formation of ethylene from an oxidized intermediate. The initial reaction is probably a Strecker degradation, but the aldehyde product is further degraded to ethylene and other products. 3. Methional (CH(3).S.CH(2).CH(2).CHO) is the most effective producer of ethylene in the model system and appears to be an intermediate in the reaction. 4. The evidence, from both tracer studies and from other precursors of ethylene in the reaction, indicates that ethylene is derived from the -CH(2).CH(2)- group of methionine.

Characterization of a single molecular QCA cell by Q-control enhanced amplitude modulation atomic force microscopy

Major technical challenges for reduction of device sizes for computation and memory are the interconnection and power dissipation problems. Molecular quantum-dot cellular automata (QCA) have been proposed as solutions to this problem. Silicon phthalocyanine (SiPc) is a possible candidate for a molecular QCA element. Therefore, it is important to develop an in situ observation technique to visualize individual SiPc molecules. We report here the first image of a single SiPc dimer in air by using quality factor control (Q-control) enhanced amplitude modulation atomic force microscopy (AFM) and an investigation of the interaction forces between the tip and SiPc dimer. The AFM was operated at 0% relative humidity in an ultrapure nitrogen environment either with or without Q-control. Theoretical simulations using the point-mass description of the AFM, demonstrated that Q-enhancement reduced the force exerted from the tip to the sample surface. Our results, consistent with theory, demonstrated that the image force was reduced and a greater height and a larger size were measured. The advantages of this method can be extended to the AFM observation of other "soft" structures, and these results can be useful for a wider community.

Adhesion enhancement of steel fibers to acrylic bone cement through a silane coupling agent

The use of a silane coupling agent (methacryloxypropyl-trichlorosilane) to improve the mechanical properties of steel fiber-reinforced acrylic bone cements was assessed. Changes to the tensile and fracture properties of bone cements reinforced with silane-coated or uncoated 316L stainless steel fibers of different aspect ratios were studied. Contact-angle measurements indicated that the coupling agent coats the metal surface through room temperature treatments in a short time (within 2 h). Push-out tests indicated that the interfacial shear strength of silane-coated 316L stainless steel rods is 141% higher than the uncoated rods. The elastic moduli, ultimate stresses, and fracture toughness of the silane-coated, steel fiber-reinforced bone cements are significantly higher than the bone cements reinforced with uncoated steel fibers. There were no differences in the tensile mechanical properties of the silane-coated or uncoated, steel fiber-reinforced cements after aging in a physiological saline solution, indicating that the bonding effectiveness is decreased by the intrusion of water at the metal-polymer interface. Because of possible biocompatibility issues with leaching of the silane coupling agent and no long-term mechanical benefit in simulated aging experiments, the use of these agents is not recommended for in vivo use.

Interpersonal influence and disordered eating behaviors in adolescent girls: the role of peer modeling, social reinforcement, and body-related teasing

This study investigated the association between interpersonal relationships, eating behaviors, and body esteem in a sample of adolescent girls. Participants included 876 girls who completed questionnaires regarding body esteem, eating behavior, peer pressure, and interpersonal relationships. Peer pressure was a strong predictor of eating behavior and body esteem after controlling for interpersonal variables. High externalized self-perceptions, self-reported teasing, and attributions about the importance of weight and shape for popularity and dating were important predictors of both body esteem and eating behavior. Also, girls who were nominated as popular by peers were more likely to engage in disordered eating and have lower body esteem. Results highlight the need for eating disorder prevention at the level of the peer group. Programs should focus on decreasing pressure to be thin, acceptance by peers for attributes other than appearance, and combating weight- and shape-related teasing within the school system.

Scanning tunneling microscopy and spectroscopy investigations of QCA molecules

Quantum-dot cellular automata (QCA), a computation paradigm based on the Coulomb interactions between neighboring cells. The key idea is to represent binary information, not by the state of a current switch (transistor), but rather by the configuration of charge in a bistable cell. In its molecular realization, the QCA cell can be a single molecule. QCA is ideally suited for molecular implementation since it exploits the molecule's ability to contain charge, and does not rely on any current flow between the molecules. We have examined using an UHV-STM some of the QCA molecules like silicon phthalocyanines and Fe-Ru complexes on Au (111) and Si (111) surfaces, which are suitable candidates for the molecular QCA approach.

Synthesis and properties of [Ru(2)(acac)(4)(bptz)](n+) (n=0,1) and crystal structure of [Ru(2)(acac)(4)(bptz)]

The neutral complex [Ru(2)(acac)(4)(bptz)] (I) has been prepared by the reaction of Ru(acac)(2)(CH(3)CN)(2) with bptz (bptz = 3,6-bis(2-pyridyl)-1,2,4,5-tetrazine) in acetone. The diruthenium(II,II) complex (I) is green and exhibits an intense metal-ligand charge-transfer band at 700 nm. Complex I is diamagnetic and has been characterized by NMR, optical spectroscopy, IR, and single-crystal X-ray diffraction. Crystal structure data for I are as follows: triclinic, P1, a = 11.709(2) A, b = 13.487(3) A, c = 15.151(3) A, alpha = 65.701(14) degrees, beta = 70.610(14) degrees, gamma = 75.50(2) degrees, V = 2038.8(6) A(3), Z = 2, R = 0.0610, for 4397 reflections with F(o) > 4sigmaF(o). Complex I shows reversible Ru(2)(II,II)-Ru(2)(II,III) and Ru(2)(II,III)-Ru(2)(III,III) couples at 0.17 and 0.97 V, respectively; the 800 mV separation indicates considerable stabilization of the mixed-valence species (K(com) > 10(13)). The diruthenium(II,III) complex, [Ru(2)(acac)(4)(bptz)](PF(6)) (II) is prepared quantitatively by one-electron oxidation of I with cerium(IV) ammonium nitrate in methanol followed by precipitation with NH(4)PF(6). Complex II is blue and shows an intense MLCT band at 575 nm and a weak band at 1220 nm in CHCl(3), which is assigned as the intervalence CT band. The mixed valence complex is paramagnetic, and an isotropic EPR signal at g = 2.17 is observed at 77 and 4 K. The solvent independence and narrowness of the 1200 nm band show that complex II is a Robin and Day class III mixed-valence complex.

Tightness of dental contact points in spaced and non-spaced permanent dentitions

One of the characteristics of normal occlusion is tight dental contact points (CPs). However, the magnitude and distribution of the tightness of a dental contact point (TDCP) in non-spaced versus spaced dentitions are unknown, as well as the mechanism controlling this arrangement. Two hypotheses were examined: the compression theory, i.e. the teeth touch each other in a compressive state; and the resistance theory, i.e. size and number of roots determine TDCP values. For the study, 60 subjects (27 men, 33 women), mean age 25 +/- 4.3 years, with a complete permanent dentition and no missing teeth were divided into spaced (n = 22) and non-spaced dentitions (n = 38). For each CP, four repeated measurements of peak strain were performed with a one-month interval. No significant differences were found between repeated measurements. All CPs demonstrated a continuous decreased TDCP in the postero-anterior direction. Consequently, in non-spaced dentitions TDCPs between molars were 100 per cent higher than incisors. The five anterior CPs of each jaw demonstrated similar TDCP values. Maxillary TDCPs versus mandibular antagonists were not significant. Mandibular TDCPs were significantly higher in men than in women (14 per cent). Anterior TDCPs were less in spaced than in non-spaced dentitions (55 per cent). Posterior TDCPs were also lower in spaced dentitions, however, to a lesser extent (25 per cent). With the exception of TDCPnon-spaced > TDCPspaced, which is partially explained by the compression theory, most of the findings support the resistance theory regulating TDCP characteristics of the permanent dentition.

Different physiological mechanisms control isovolumetric regulation and regulatory volume decrease in chick embryo cardiomyocytes

Cultured chick embryo cardiac myocytes submitted to a 180 mOsm/kg hyposmotic solution swell present a regulatory volume decrease (RVD). This RVD is mediated by a Ca(2+)influx followed by a 40% loss of total taurine content accompanied by the loss of lesser amounts of other osmolytes. Kidney cells respond to a gradual change in osmolality by maintaining their volume at the initial level. This is termed isovolumetric regulation (IVR), which may activate regulatory processes other than those observed with sudden changes in osmolality. When cardiac myocytes were exposed to a gradual change in osmolality, they show a partial IVR which is not dependent upon extracellular Ca(2+). Potassium channel blockers, quinidine and Ba(2+), and the chloride channel blocker, diphenylamine-2-carboxylate (DPC), compromise IVR in our model. Tritiated taurine loss and total intracellular K(+)contents were analyzed in cultured cardiomyocytes submitted to a gradual change in osmolality. The cultured cells lost approximately 10% of their taurine and 35% of their total K(+). These findings suggest that different compensatory mechanisms are activated when cells are exposed to stepwise and gradual changes in osmolality. Inorganic osmolytes (through conductive pathways) are preferentially mobilized during the physiological and/or patho-physiological IVR situation, perhaps reflecting energetic conservation in response to a less traumatic event for the cardiac myocytes.

Rescuing the N-cadherin knockout by cardiac-specific expression of N- or E-cadherin

Cell-cell adhesion mediated by some members of the cadherin family is essential for embryonic survival. The N-cadherin-null embryo dies during mid-gestation, with multiple developmental defects. We show that N-cadherin-null embryos expressing cadherins using muscle-specific promoters, alpha- or beta-myosin heavy chain, are partially rescued. Somewhat surprisingly, either N-cadherin or E-cadherin was effective in rescuing the embryos. The rescued embryos exhibited an increased number of somites, branchial arches and the presence of forelimb buds; however, in contrast, brain development was severely impaired. In rescued animals, the aberrant yolk sac morphology seen in N-cadherin-null embryos was corrected, demonstrating that this phenotype was secondary to the cardiac defect. Dye injection studies and analysis of chimeric animals that have both wild-type and N-cadherin-null cells support the conclusion that obstruction of the cardiac outflow tract represents a major defect that is likely to be the primary cause of pericardial swelling seen in null embryos. Although rescued embryos were more developed than null embryos, they were smaller than wild-type embryos, even though the integrity of the cardiovascular system appeared normal. The smaller size of rescued embryos may be due, at least in part, to increased apoptosis observed in tissues not rescued by transgene expression, indicating that N-cadherin-mediated cell adhesion provides an essential survival signal for embryonic cells. Our data provide in vivo evidence that cadherin adhesion is essential for cell survival and for normal heart development. Our data also show that E-cadherin can functionally substitute for N-cadherin during cardiogenesis, suggesting a critical role for cadherin-mediated cell-cell adhesion, but not cadherin family member-specific signaling, at the looping stage of heart development.

Na+/K+-ATPase inhibition during cardiac myocyte swelling: involvement of intracellular pH and Ca2+

Previous studies in chick embryo cardiac myocytes have shown that the inhibition of Na+/K+-ATPase with ouabain induces cell shrinkage in an isosmotic environment (290 mOsm). The same inhibition produces an enhanced RVD (regulatory volume decrease) in hyposmotic conditions (100 mOsm). It is also known that submitting chick embryo cardiomyocytes to a hyperosmotic solution induces shrinkage and a concurrent intracellular alkalization. The objective of this study was to evaluate the involvement of intracellular pH (pHi), intracellular Ca2+ ([Ca2+]i) and Na+/K+-ATPase inhibition during hyposmotic swelling. Changes in intracellular pH and Ca2+ were monitored using BCECF and fura-2, respectively. The addition of ouabain (100 microM) under both isosmotic and hyposmotic stimuli resulted in a large increase in [Ca2+]i (200%). A decrease in pHi (from 7.3 +/- 0.09 to 6.4 +/- 0.08, n = 6; p < 0.05) was only observed when ouabain was applied during hyposmotic swelling. This acidification was prevented by the removal of extracellular Ca2+. Inhibition of Na+/H+ exchange with amiloride (1 mM) had no effect on the ouabain-induced acidification. Preventing the mitochondrial accumulation of Ca2+ using CCCP (10 microM) resulted in a blockade of the progressive acidification normally induced by ouabain. The inhibition of mitochondrial membrane K+/H+ exchange with DCCD (1 mM) also completely prevented the acidification. Our results suggest that intracellular acidification upon cell swelling is mediated by an initial Ca2+ influx via Na+/Ca2+ exchange, which under hyposmotic conditions activates the K+ and Ca2+ mitochondrial exchange systems (K+/H+ and Ca2+/H+).

Cytoskeletal involvement during hypo-osmotic swelling and volume regulation in cultured chick cardiac myocytes

The membrane skeleton in spherical cardiac myocytes subjected to hypo-osmotic challenge was examined by laser scanning confocal microscopy. A distinct cortical layer intimately localized under the plasmalemma was revealed for spectrin and actin (including filamentous actin and alpha-sarcomeric actin). Desmin filaments were abundant and in close contact with the plasmalemma. During swelling and subsequent regulatory volume decrease (RVD) the structural integrity of these cytoskeletal elements remained intact, and the close association between actin and plasmalemma persisted as confirmed by double immunolabeling. Subplasmalemmal beta-tubulin labeling was sparse. Hypo-osmotic conditions disrupted the microtubules and depolymerized tubulin. Neither pretreatment with taxol nor with colchicine, resulted in any effect on cell volume regulation. The present results show that actin, desmin, and spectrin contribute to a subplasmalemmal cytoskeletal network in spherical cardiac myocytes, and that this membrane skeleton remains structurally intact during swelling and RVD. It is suggested that the integrity of this membrane skeleton is important for stabilization of the plasmalemma and the membrane-integrated proteins during hypo-osmotic challenge, and that it may participate in the regulation of the cell volume.

Postnatal lethality of P-cadherin/desmoglein 3 double knockout mice: demonstration of a cooperative effect of these cell adhesion molecules in tissue homeostasis of stratified squamous epithelia

To investigate the cooperativity of different cell adhesion molecules in maintaining the structural integrity of the epidermis, we have generated mice deficient for both a classical cadherin, P-cadherin, and a desmosomal cadherin, desmoglein 3. In epithelial cells, P-cadherin is localized to the adherens junction, whereas desmoglein 3 is found in desmosomes. Previous studies have shown that these two junctional complexes are important for keratinocyte cell-cell adhesion. Both P-cadherin and desmoglein 3 expression are restricted to the basal and most immediate suprabasal cells of the epidermis, whereas both proteins are found throughout the oral mucosal epithelium. Although P-cadherin mutant mice have no apparent defect in epithelial cell adhesion, the desmoglein 3 mutant phenotype resembles that of patients with the autoimmune disease pemphigus vulgaris, in that the mice develop spontaneous mucous membrane blisters and trauma-induced skin blisters. The oral lesions in DSG3-/- mice reduce their food intake, resulting in a runted phenotype; however, most animals recover and live past weaning age. In contrast, animals mutant for both P-cadherin and desmoglein 3 die before weaning. The majority of the double mutant animals die around 1 wk after birth, apparently due to malnutrition. These studies suggest that loss of P-cadherin leads to a more severe desmoglein 3 mutant phenotype in the double knockout mice. This is the first in vivo evidence of possible synergism between a classical and desmosomal cadherin.

Permeabilization by streptolysin-o reveals a role for calcium-dependent protein kinase c isoforms alpha and beta in the response of cultured cardiomyocytes to hyposmotic challenge

Immunocytochemical techniques indicate that the uninhibited activity of protein kinase C alpha and protein kinase C beta are necessary for a normal regulatory volume decrease (RVD) response of cultured chick embryo cardiomyocytes subjected to a hyposmotic environment. Antibodies against protein kinase C isoforms alpha, beta, gamma and epsilon were introduced into the cultured myocytes using a developed streptolysin-O (SLO) permeabilization technique that allows the targeted cells to accumulate large biomolecules without perturbing their normal physiological state. The loaded cells were then tested for their ability to RVD when submitted to hypo-osmotic stimulus. Results show that exposing the cultured cells to SLO in the presence of antibodies against protein kinase C alpha and beta, prior to volume challenge, significantly slows the RVD rate. Additional experiments that combined anti-alpha and anti-beta antibodies in the same exposure media did not result in a significantly different rate than the anti-alpha or anti-beta rates alone. The evidence gained in this study is in agreement with previous work in the cultured chick embryo cardiomyocyte that report the involvement of a calcium dependent protein kinase C in the signal transduction pathway of the RVD.

Comparisons of different stages of chick embryonic development by the physiological regulatory response to hyposmotic challenge

Cardiac myocytes isolated and cultured from 11 day chick embryos present a Ca(2+)-dependent regulatory volume decrease (RVD) when exposed to hyposmotic stimulus. The RVD of myocytes from different embryonic stages were analyzed to evaluate their physiological performance through development. Among the several embryonic stages analyzed (6, 11, 16 and 19 days) only 19 day cardiac myocytes present a greater RVD when compared with 11 day (considered as control), the other ages showed no difference in the regulatory response. As it is known that RVD is Ca(2+) dependent, we decided to investigate the transient free Ca(2+) response during the hyposmotic swelling of the 11 and 19 day stages. The 11 day cardiac myocyte showed a transient 40% increase in intracellular free Ca(2+) when submitted to hyposmotic solutions, and the free Ca(2+) returned to baseline levels while the cells remained in hyposmotic buffer. However, the intracellular free Ca(2+) transient in the 19 day cells during hyposmotic challenge increases 100% and instead of returning to baseline levels, declines to 55% above control, well after the 11 day transient has returned to baseline. Also, quantitative fluorescence microscopy revealed that 19 day cardiac myocytes have more sarcoplasmic reticulum (SR) Ca(2+) ATPase sites per cell as compared to the 11 day cells. Our findings suggest that 19 day cells have more developed intracellular Ca(2+) stores (SR). By evoking the mechanism of Ca(2+) induced Ca(2+) release, the cells have more free Ca(2+) available for signaling the RVD during hyposmotic swelling.

Membrane skeleton in cultured chick cardiac myocytes revealed by high resolution immunocytochemistry

Distribution of cytoskeletal proteins with emphasis on the membrane-cytoskeleton interface was examined in cultured cardiac myocytes. Using specific antibodies recognizing alpha-sarcomeric actin, desmin, beta-tubulin, spectrin/alpha-fodrin and ankyrin, respectively, the cellular localization of these cytoskeletal proteins was detected by laser scanning confocal microscopy. In addition, the fine filamentous structure of these proteins was identified by combining silver-enhanced immunogold labelling with electron microscopy. The latter technique employed the sequence of quick-freezing, deep-etching and rotary shadowing of the specimens. Conventional transmission electron microscopy of the spherical cardiac myocytes revealed a filamentous submembranous layer, approximately 100 nm thick. Specific immunolabelling of alpha-sarcomeric actin and spectrin/alpha-fodrin as well as ankyrin was seen beneath the plasmalemma. A three-dimensional meshwork of spectrin/alpha-fodrin was shown. Numerous desmin filaments that exhibited a tortuous course throughout the cells were also observed running in parallel with the surface in the submembranous area, whereas beta-tubulin was infrequently detected in these areas. In conclusion, the present study shows that spherical cardiac myocytes contain a distinct and complex three-dimensional membrane skeleton. Major constituents of this distinct submembranous layer were spectrin/alpha-fodrin fibres as well as actin and desmin filaments.

Estrogen replacement therapy and cognitive decline in memory-impaired post-menopausal women

BACKGROUND

Estrogen replacement therapy (ERT) may delay dementia-related cognitive decline in post-menopausal women, but few studies have longitudinally examined this relationship and none has controlled for baseline functioning or concurrent medication.

METHODS

We report the results of a 1-year retrospective longitudinal study examining cognitive functioning in female estrogen and nonestrogen users (n = 3128) who presented to the state of California memory disorder clinics in a naturalistic multisite study of senile dementia, Alzheimer's type (SDAT), and other cognitive impairments.

RESULTS

At baseline, estrogen users had significantly lower rates of SDAT diagnoses (possible and probable) than nonestrogen users, and significantly higher rates of the lesser diagnoses of "cognitive impairment" and "no dementia." ERT was significantly associated with higher cognitive functioning at baseline and at 1 year follow-up (n = 358). Nonestrogen users deteriorated significantly from baseline to follow-up; estrogen users did not. Results were similar in groups matched on baseline Blessed-Roth Dementia Rating Scale (BRDRS) ratings (n = 32) and in a variety of subpopulations.

CONCLUSIONS

These findings are consistent with estrogen acting as a protective factor against cognitive deterioration in post-menopausal women with SDAT and other cognitive impairments, and may suggest an increased effect in earlier stages of cognitive impairment.

Field stimulation of isolated chick heart cells: comparison of experimental and theoretical activation thresholds

INTRODUCTION

This study examines the accuracy of using membrane models to predict activation thresholds for chick heart cells during field stimulation.

METHODS AND RESULTS

Activation thresholds were measured experimentally in ten embryonic chick heart cells at 37 degrees C for stimulus durations 0.2 to 40 msec. Activation was assessed by observing the mechanical twitch of the cell. The heart cells ranged in diameter from 15.0 to 26.7 microm. Since the electric field required for activation depends on diameter, the thresholds were expressed as the maximum field-induced transmembrane potential, Vth = 1.5 a Eth, where a is the cell radius and Eth is the strength of the electric field at threshold. A cell model was created using a singular perturbation method and membrane models describing the ionic currents of a heart cell. The study used membrane models of Ebihara and Johnson (1980), Luo and Rudy (1991), Shrier and Clay (1994), and their combinations. The results show that for stimuli longer than 1 msec, theoretical activation thresholds were within one standard deviation of experimental thresholds. For shorter stimuli, the models failed to predict thresholds because of a premature deactivation of the sodium current. The modification of the m gates dynamics, so that they closed with a time constant of 1.4 msec, allowed to predict thresholds for all durations. The root mean square error between experimental and theoretical thresholds was 6.14%.

CONCLUSIONS

The existing membrane models can predict thresholds for field stimulation only for stimuli longer than 1 msec. For shorter stimuli, the models need a more accurate representation of the sodium tail current.

Developmental patterns in security of attachment to mother and father in late childhood and early adolescence: associations with peer relations

This study examined developmental differences in two dimensions of attachment security (parental availability and child dependency on parents) in late childhood (N = 274) and early adolescence (N = 267) and their association with peer relations. Children's perceptions of mother's availability and boys' perceptions of father's availability did not differ as a function of age. Dependency on parents, however, decreased with age. Findings highlight the importance of distinguishing between parental availability and reliance on parental help when measuring attachment developmentally. Children's reports of positive friendship qualities and lack of conflict in their best friendships were related to attachment to both mother and father, whereas the presence of a reciprocated friendship and popularity were not. Father availability was a particularly important predictor of lower conflict with best friends. Findings indicate that the quality of parent-child attachment generalizes primarily to the quality of children's close peer relations.

The dentition of Abraham's people. Why Abraham left Mesopotamia

Ancient Mesopotamia (southern Iraq) in 2000 B.C. was the home of the biblical figure Abraham and his people. An analysis of skeletal material from cemeteries in the ancient cities of Ur (birthplace of Abraham) and Kish shows a homogeneous, short-lived population that suffered severe dental attrition (95 percent of inhabitants), periodontal disease (42 percent) and caries (two percent). Many oral congenital and neoplastic lesions were noted Skeletal (dental) evidence indicates the population suffered from extensive disease and nutritional deficiency. Of special note was a possible case of endodontic treatment. The people of Abraham had modern dentition but relatively poor dental health. It is probable that Abraham, if in truth he existed, left Mesopotamia because of the threat of famine, as evidenced by biblical record, geologic strata and dental analysis.

Antigen-specific antibody responses in lupus patients following immunization

OBJECTIVE

To determine the safety and efficacy of 3 clinically relevant vaccines in patients with systemic lupus erythematosus (SLE).

METHODS

We studied 73 consecutive SLE patients immunized with pneumococcal, tetanus toxoid (TT), and Haemophilus influenzae type B (HIB) vaccines. Patients were evaluated preimmunization and 12 weeks postimmunization for disease activity and immunization side effects.

RESULTS

Eighty-four percent of the SLE patients developed a 4-fold titer increase in response to at least 1 vaccine, with 51% developing a 2-fold titer increase with all 3 vaccines. The majority of SLE patients developed protective levels of antibody to TT (90%) and HIB (88%). Although protective antibody levels could not be determined for pneumococcus, almost half of the patients (47%) developed a 4-fold antibody response. There was a trend toward a lower antibody response in patients with active disease treated with immunosuppressive therapy. Overall lupus disease activity was unaffected by immunization.

CONCLUSION

Immunization is safe in SLE patients, with the overwhelming majority developing protective antibody levels. Therefore, SLE patients should receive immunizations according to the recommendations of the Centers for Disease Control and Prevention and the Immunization Practices Advisory Committee.

Rapid palatal expansion. Part 3: strains developed during active and retention phases

Patterns of strain accumulation/dissipation during the active and retention phases of rapid palatal expansion treatment were studied in a preliminary animal model (5 cats) followed by clinical study (14 patients). Two uni-axial strain gauges were bonded to the arms of a hyrax screw. The strain gauges were wired intraorally to a common male connector and protected against salivary assault. For strain registration, the connector was hooked to a switch and balance instrument and a digital strain indicator. The screw was activated (4 x 1/4 turn) every 3 to 4 days and strain and interarch distances were measured during rapid palatal expansion active and retention phases. Interarch distances were also measured during the relapse phase. Both studies share the same results. Strains and expansion increased progressively during active and retention phases of rapid palatal expansion. No difference between anterior and posterior strain was found. An immediate dental strain response that occurred during screw activations (intrasession strain) was related to tooth compression in the PDL. During the 3 to 4 day pause, a delayed skeletal strain response (intersession strain) developed that was inverted or continuous to the preceding intrasession strain. Complete dissipation of residual strains was limited to the first 1 to 3 active phase sessions. Strain accretion resulted essentially from intersession strain build-up. Strain level was preserved during the retention phase, apparently due to relapse strains. Relapse strains could not be measured but are inferred from the predominant interarch rebound measured during the relapse phase. Clinically, an extension of the intersession intervals and the retention phase are recommended.

Rapid palatal expansion. Part 2: Dentoskeletal changes in cats with patent versus synostosed midpalatal suture

Intercanine expansion (C-C) following rapid palatal expansion is made up of sutural displacement (Sd-Sd), tooth tip (Tt-Tt), tooth displacement (Td-Td), and alveolar process tipping and bending (At+b-At+b). The involvement of these four components was studied on 10 rapid palatal expansion treated and two control cats during an active phase (25 days), a retention phase (60 days), and a relapse phase (60 days). The midpalatal suture was analyzed for linear measurements, radiopaque versus radiolucent zones and optical density from occlusal radiographs. Nine treated cats exhibited sutural split and one treated cat showed no split as a result of synostosis of the suture. The contribution of the four constituents [(Sd-Sd):(Tt-Tt):(Td-Td):(At+b-At+b)] to the C-C expansion changed from active to relapse phase from [45%:15%:25%:15%] to [50%:25%:25%:0%] in the animals with sutural split and from [0%:40%:60%:0%] to [0%:0%:100%:0%] in the cat without sutural split, implying the major role of sutural displacement in patent suture, and tooth displacement in synostosed suture. The latter indicates the potential buccal corticalis fenestration, dehiscence or perforation in synostosed suture undergoing RPE. In patent suture (animals with sutural split), optical density increased during rapid palatal expansion (soft tissue build-up) and decreased during retention (remineralization) and relapse phases (medial convergence of the palatal processes). In the animal without sutural split, a continuous decrease in the optical density (predetermined ossification) was found. The progressive six-fold surge in coefficient of variation of C-C expansion during the relapse phase indicates limitation in predicting rapid palatal expansion stability. Clinically, the use of serial occlusal radiographs during rapid palatal expansion is recommended to evaluate patency and extent of retention period.