Topologically protected superconducting ratchet effect generated by spin-ice nanomagnets

We have designed, fabricated and tested a robust superconducting ratchet device based on topologically frustrated spin ice nanomagnets. The device is made of a magnetic Co honeycomb array embedded in a superconducting Nb film. This device is based on three simple mechanisms: (i) the topology of the Co honeycomb array frustrates in-plane magnetic configurations in the array yielding a distribution of magnetic charges which can be ordered or disordered with in-plane magnetic fields, following spin ice rules; (ii) the local vertex magnetization, which consists of a magnetic half vortex with two charged magnetic Néel walls; (iii) the interaction between superconducting vortices and the asymmetric potentials provided by the Néel walls. The combination of these elements leads to a superconducting ratchet effect. Thus, superconducting vortices driven by alternating forces and moving on magnetic half vortices generate a unidirectional net vortex flow. This ratchet effect is independent of the distribution of magnetic charges in the array.

Abstract P2-02-16: Use of cell-free circulating RNA and expression of PD-L1 and HER2 in plasma to monitor and predict clinical response in metastatic breast cancer patients

Background: In addition to traditional radiology tests, cell-free circulating tumor RNA (cfRNA) extracted from plasma of cancer patients (pts) provides a means of evaluating tumor response, but based on molecular changes in the tumor. Measuring dynamic changes in gene expression and levels of total cfRNA (per ml of plasma) in metastatic patients has shown great potential for evaluating disease status and predicting outcome to anti-tumoral therapy in advance of imaging. Though checkpoint inhibitors have not been assessed widely in breast cancer, TNBC has shown mild responses to pembrozilumab and atezolizumab, with significantly better responses in pts with detectable PD-L1 expression.

Methods: Blood was drawn from pts at approximately 6-week intervals under various therapies and CT scans were performed at approximately 3-month intervals. CfRNA was extracted from the resulting plasma and reverse transcribed with random hexamers to cDNA. Levels of cfRNA were quantitated by RT-qPCR and correlated with pt response (PR/SD/PD), as determined by CT scans. Levels of gene expression in cfRNA (including PD-L1 and HER2) were monitored in pts across blood draws.

Results: A total of 28 breast cancer pts were enrolled in a 1-year clinical study. Of pts, 39% (11/28) were Caucasian and 36% (10/28) Hispanic. 19 pts completed the first two cycles of therapy: 2 pts had PR and showed no change (NC) or decrease (DEC) in levels of cfRNA, 11 pts achieved SD with 8 showing DEC or NC in cfRNA levels, and 6 pts had PD and all underwent increases (INC) in cfRNA levels (median increase: 788 ng/mL plasma) which correlated with progressive disease status. Of pts with SD/PR, 4 showed either an emergence or significant increase in PD-L1 expression across blood draws (3.7-98 ct); of PD pts, 1 showed a significant emergence of PD-L1 expression (12.5 ct) across blood draws. 3/5 of these PD-L1 expressing pts were being treated with an everolimus combination; the emergence or increase of PD-L1 in response to this therapy suggests use of checkpoint inhibitors as an option for these pts. In response to therapy, 3 of 5 pts had PD-L1 cfRNA levels above levels predictive of response to nivolumab in lung cancer pts. In the only pt with hyperexpressed HER2, the disappearance of HER2 cfRNA matched positive response (PR) to treatment with trastuzumab. PD-L1 decreased concomitantly for this pt.

Conclusion: We found a strong correlation between clinical responses and changes in plasma levels of ctRNA in breast cancer (84%). Most of these were documented several weeks before imaging was done. Levels of PD-L1 and HER2 expression in plasma can also be used to monitor pt response to specific therapies. The emergence of PD-L1 expression in response to various therapies in breast cancer may confer sensitivity to checkpoint inhibitor therapy.

Citation Format: Castrellon AB, Velez M, Raez LE, Danenberg K, Rabizadeh S, Usher J, Jaimes Y, Hunis B, Bittencourt AC, Milillo A, Blaya M, Habaue C, Danenberg PV. Use of cell-free circulating RNA and expression of PD-L1 and HER2 in plasma to monitor and predict clinical response in metastatic breast cancer patients [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P2-02-16.

Abstract P5-16-19: Evaluation of weekly paclitaxel plus carboplatin followed by anthracycline chemotherapy on the neoadjuvant treatment of patients with triple-negative breast cancer

Background

Triple negative breast cancer (TNBC) accounts for 15 to 20 % of the invasive breast cancers. Pathological complete response (pCR) in this subgroup of breast cancer is associated with improved long term event free survival. Results from previous studies indicate that the addition of carboplatinum (Cb) to standard neoadjuvant anthracycline-taxane chemotherapy results in an increase in pCR. One of the investigational arms of the CALGB 40603 tested paclitaxel 80 mg/m2 once a week (wP) for 12 weeks with concurrent Cb (area under curve 6) once every 3 weeks for four cycles, followed by doxorubicin plus cyclophosphamide once every 2 weeks (ddAC) for four cycles. Although effective this regimen has been difficult to reproduce in the daily practice. The purpose of this study was to evaluate the effectiveness and tolerability of wP in combination with weekly Cb (wP+wCb) area under curve 2 (AUC=2) followed by anthracycline chemotherapy.

Methodology

The electronic medical record system was used to identify female patients 18 years of age or older with clinical stage I-III (TNBC) who received neoadjuvant chemotherapy of wP+wCb (AUC=2) before or after anthracycline chemotherapy between January 1, 2014 and March 1, 2016. The primary outcome was to evaluate the tolerability of fractionating carboplatin to weekly infusions in combination with weekly paclitaxel. The secondary outcomes included the pCR (no evidence of invasive tumor in the breast and axilla), Residual Cancer Burden (RCB), the number of cycles received in each chemotherapy regimen and frequency of chemotherapy related toxicities.

Results:

For the 32 eligible patients, median age: 51 years, Stage I: 6%, Stage II: 68%, Stage: III 26%, germline BRCA mutation: 10%, KI 67 > 75% : 72%. 93% of the patients received 11-12 cycles of wP+wCb and 83% received all 4 planned cycles of anthracycline chemotherapy. 83% of patients completed all planned therapy. pCR and RCB 0/1 rates were 60% (19/32) and 75% (24/32) respectively. RCB 2: 22% (7/32), RCB 3: 3% (1/32). 93% of the patients experienced grade 3 neutropenia during wP+wCb requiring GCSF, Grade 3 anemia was seen in 15 % (5/32) and Grade 3 thrombocytopenia was seen in 18 % (6/32).

Conclusion:

The combination of neoadjuvant chemotherapy with wP+wCb before or after anthracycline chemotherapy was well tolerated among patients with TNBC as demonstrated by the fact that most participants were able to receive all planned 12 cycles of wP+ wCb and all 4 cycles of anthracycline chemotherapy. Complete pathologic response rates were comparable to historically seen. The findings support the continued use of this treatment modality in the general practice.

Citation Format: Castrellon AB, Velez M, Blaya M, Barnick S, Dumais K, LeCroy N. Evaluation of weekly paclitaxel plus carboplatin followed by anthracycline chemotherapy on the neoadjuvant treatment of patients with triple-negative breast cancer [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P5-16-19.

A comparison of three methods for detecting KRAS mutations in formalin-fixed colorectal cancer specimens

BACKGROUND

KRAS mutation testing is required to select patients with metastatic colorectal cancer (CRC) to receive anti-epidermal growth factor receptor antibodies, but the optimal KRAS mutation test method is uncertain.

METHODS

We conducted a two-site comparison of two commercial KRAS mutation kits - the cobas KRAS Mutation Test and the Qiagen therascreen KRAS Kit - and Sanger sequencing. A panel of 120 CRC specimens was tested with all three methods. The agreement between the cobas test and each of the other methods was assessed. Specimens with discordant results were subjected to quantitative massively parallel pyrosequencing (MPP). DNA blends were tested to determine detection rates at 5% mutant alleles.

RESULTS

Reproducibility of the cobas test between sites was 98%. Six mutations were detected by cobas that were not detected by Sanger, and five were confirmed by MPP. The cobas test detected eight mutations which were not detected by the therascreen test, and seven were confirmed by MPP. Detection rates with 5% mutant DNA blends were 100% for the cobas and therascreen tests and 19% for Sanger.

CONCLUSION

The cobas test was reproducible between sites, and detected several mutations that were not detected by the therascreen test or Sanger. Sanger sequencing had poor sensitivity for low levels of mutation.

Pregnancies exposed to methadone, methadone and other illicit substances, and poly-drugs without methadone: a comparison of fetal neurobehaviors and infant outcomes

BACKGROUND

It is suspected that there is a continuum of impairment among prenatally drug-exposed infants, such that opioid and/or poly-drug exposure confers the highest risk for adverse neonatal outcomes than other classes of substances or single substance exposures. Suitable control groups are difficult to identify. This study compared fetal neurobehavioral development and infant outcomes in offspring of three groups of pregnant women in drug treatment. Exposure groups include: Methadone+other illicit substances (MM+Poly) and two groups currently abstinent for poly drug exposures: Methadone only (MM/A) and Non-Methadone (NM/A).

METHODS

Forty-nine women (19 MM+Poly, 18 MM/A, and 12 NM/A) underwent fetal monitoring at 36 weeks gestation at peak and trough levels of methadone (MM+Poly; MM/A) or at comparable morning and afternoon times (NM/A). Fetal heart rate (FHR), heart rate variability (FHRV) and motor activity (FM) data were collected. Infant measures included birth outcomes and Neonatal Abstinence Syndrome (NAS) assessment.

RESULTS

As compared to the NM/A group, cardiac measures were decreased in methadone-exposed fetuses at peak levels. FHR was significantly more suppressed in the MM+Poly group. FM was significantly lower in the MM/A vs. the NM/A group at both peak and trough, indicative of more persistent exposure effects. The MM+Poly group delivered 1 week earlier and required NAS pharmacological treatment twice as often as the MM/A group.

CONCLUSIONS

Results support the notion that poly-drug exposure may potentiate the effects of methadone on the fetus and infant and highlights the need for intensified treatment for methadone-maintained women who abuse other substances.

Identification of supportive care needs in a sample of Puerto Rican cancer patients with the Supportive Care Needs Survey-34 (SCNS-34)

e20697

Background: The assessment of supportive care needs is important in the management of cancer patients. The Supportive Care Needs Survey (SCNS-34) was administered to a population of Puerto Rican cancer patients to assess their perceived needs in five domains (psychological, health system and information, physical and daily living, patient care and support, and sexuality.) Methods: Patients attending the surgical, radiation and medical oncology clinics at the Puerto Rico Medical Center participated in the study. After informed consent, patients completed the Spanish- Puerto Rican translation of the SCNS-34. A second instrument to measure the quality of the SCNS-34 was administered. Demographic and clinical data was obtained from medical records. Descriptive, univariate and multivariate analysis was performed to assess correlation between reported needs and demographic and clinical data. To assess the validity and consistency of the Spanish Puerto Rican translation of the SCNS-34, the Cronbach's alpha test was used. Results: A total of 103 patients participated in the study (female n=66; male n=37). Median age was 54 years. The most common malignancies were breast cancer (29 patients), gynecologic cancers (22 patients), prostate cancer (17 patients) and gastrointestinal cancers (14 patients). The overall internal consistency of the instrument was 0.882. Patients perceived needs were highest in the domains of sexuality (67%), physical and daily living (55.3%), and psychological (38.8%). Logistic regression analysis demonstrated that younger age was an independent predictor of perceived needs in the psychologic domain (p=0.010). Also, a diagnosis of breast cancer was a significant predictor of perceived needs in the health system and information domain (p=0.020). Being a female was correlated with reporting needs in the domain of physical and daily living (p=0.009). Educated patients were more prone to perceive needs in the domains of sexuality (p=0.045). Conclusions: The Spanish- Puerto Rican translation of the Supportive Care Needs Survey (SCNS-34) showed satisfactory internal consistency and validity. The supportive care needs of Puerto Ricans cancer patients seem to be affected by age, gender, and cancer site.

No significant financial relationships to disclose.

Improved COBAS TaqMan hepatitis C virus test (Version 2.0) for use with the High Pure system: enhanced genotype inclusivity and performance characteristics in a multisite study

We have evaluated the COBAS TaqMan hepatitis C virus (HCV) test (version 2.0) for use with the High Pure system (HCVHPS V2), a new, revised real-time reverse transcription-PCR assay developed to improve the genotype quantitation of version 1.0 (HCVHPS V1). Revisions were made in the wash buffer and in the reverse transcription temperature. The genotype inclusivity of HCVHPS V2 was evaluated at three different sites, using HCVHPS V2, HCVHPS V1, and the COBAS AMPLICOR HCV MONITOR test (version 2.0) (CAHCM). The fully automated COBAS Ampliprep/COBAS TaqMan HCV test was also used in one of the participating laboratories. The mean differences in HCV RNA values between HCVHPS V2 and CAHCM and between HCVHPS V2 and HCVHPS V1 ranged from -0.21 to 0.13 log and from 0.24 to 1.27 log, respectively, with >0.5-log differences for genotypes 2, 3, 4, and 5. With a NIBSC panel of HCV genotypes 1 through 6, the measured HCVHPS V2 values were within 0.25 log of the nominal values for all 6 genotypes. When serial dilutions of genotype-specific clinical HCV specimens were tested, the assay showed a limit of detection between 10 and 20 IU/ml and a linear range of 25 IU/ml to 3.91 x 10(8) IU/ml. Clinical and analytical specificities of 100% were demonstrated with 100 HCV-seronegative specimens as well as with 12 non-HCV members of Flaviviridae and 22 additional microorganisms. These data indicate that HCVHPS V2 is a robust and accurate test for the quantitation of all six HCV genotypes and useful in monitoring viral load in all clinical HCV specimens.

Assessment of the Efficacy of Nonablative Long-Pulsed 1064-nm Nd:YAG Laser Treatment of Wrinkles Compared at 2, 4, and 6 Months

Rhytides represent an aesthetic problem for a large percentage of the population. Many methods, both noninvasive and invasive, have been used for the treatment of wrinkles. Recently, the long-pulsed 1064-nm Nd:YAG laser has been shown to enhance dermal collagen synthesis without damaging the epidermis. The purpose of this preliminary study is to evaluate the use of the long-pulsed Nd:YAG laser in the nonablative treatment of periocular and perioral wrinkles. Ten patients with facial wrinkles were treated with the long-pulsed 1064-nm Nd:YAG laser, at a spot size of 5 mm in diameter, energy density of 13 J/cm2, exposure time per pulse of 300 microseconds, and a repetition rate of 7 Hz. All patients had a total of three treatments, once every 2 weeks. Subjective (patient satisfaction index [SI]) and objective (both physician- and computer program-based clinical index [CI]) assessments were performed before the first and third treatment sessions, and at 2, 4, and 6 months after the last treatment. At 6 months after the final treatment session, the patients' subjective SI was maintained at 40%, and had peaked at 50% 2 months after the final session. Physician assessment showed a CI of 40% at the 6-month assessment point and the computer program showed a 50% CI. The greatest level of effect with long-pulsed Nd:YAG laser nonablative skin rejuvenation for facial wrinkles was seen 2 months after the final treatment. Effects were still visible at the 6-month period, but showed a tendency to decrease. Maintenance treatments are required to achieve good patient satisfaction.

Non-ablative facial skin photorejuvenation with an intense pulsed light system and adjunctive epidermal care

Laser skin resurfacing is popular, but the appearance of the face during healing is unpleasant. Non-ablative photorejuvenation with intense pulsed light (IPL) has been reported as being successful but with varied results. In this study we sought the possibility of enhancing the clinical effects with adjunctive epidermal care. Twenty-five women aged from 32 to 68, skin types I-IV, with a variety of wrinkle types and other conditions associated with photoaged skin, were treated with IPL according to our parameters over six sessions coupled with an adjunctive pretreatment micropeel and applications of nutritive and antipigmenting creams. Macroscopic and histological assessments were performed. At weeks 4 and 8 fair to good satisfaction was noted in 17 and 19 patients, and poor satisfaction in 8 and 6 patients, respectively. The histology showed good dermal collagen remodelling in all cases, with a reduction in elastosis. The results of IPL photorejuvenation can be enhanced, as our trials showed. The good patient satisfaction obtained was clearly demonstrated in the histologies and evaluations throughout the study.

Effects of iron deficiency on the secretion of interleukin-10 by mitogen-activated and non-activated murine spleen cells

Interleukin (IL)-10 plays crucial regulatory roles in immune responses by inhibiting the secretion of several cytokines (IL-2, IL-12, interferon-gamma (IFN-gamma)) and lymphocyte proliferation. Iron deficiency, a public health problem for children, alters these immune responses. To determine whether these changes are related to altered IL-10 secretion, we measured IL-10 in 24 and 48 h supernatant of spleen cell cultures from iron deficient (ID), control (C), pairfed (PF), and ID mice fed the control diet (iron repletion) for 3 (R3) and 14 (R14) days (d, n = 12/group). Mean levels of hemoglobin, hematocrit, and liver iron stores varied as follows: C approximately equal PF approximately equal R14 > R3 > ID (P < 0.01). Mean baseline IL-10 levels of ID mice tended to be higher than those of other groups (P > 0.05, ANOVA). Mean IL-10 levels secreted by concanavalin A (Con A) and antibody raised against cluster of differentiation molecule 3 (anti-CD3)-treated cells (+/-background) were lower in ID than in C (48 h) and iron replete mice (P < 0.05). Underfeeding also reduced IL-10 secretion by anti-CD3-treated cells (48 h, P < 0.05). Lymphocyte proliferative responses to anti-CD3 +/- anti-CD28 antibodies were lower in ID than in C and PF mice, and they were corrected by iron repletion (P < 0.05). IL-10 levels negatively correlated with indicators of iron status (r <or= -0.285) and lymphocyte proliferation (r <or= -0.379 [r <or= -0.743 for ID mice]), but positively correlated with IFN-gamma levels (r <or= 0.47; P < 0.05). Data suggest that iron deficiency has a generalized deleterious effect on cells that secrete both cytokines. Reduced IL-10 secretion by activated cells does not overcome the inhibition of lymphocyte proliferation due to other factors of T cell activation that are regulated by iron.

Clinical and histologic effects of facial skin rejuvenation with pulsed- and continuous-wave flash-scanned CO(2) lasers

LEARNING OBJECTIVES

The reader is presumed to have some understanding of the use of lasers in skin resurfacing. After studying the article, the participant should be able to: Physicians may earn 1 hour of Category 1 CME credit by successfully completing the examination based on material covered in this article. The examination begins on page 409.

BACKGROUND

The selection of the ideal laser for facial resurfacing is debatable.

OBJECTIVE

The purpose of the study was to determine whether any clinical and histologic differences existed in short- and long-term results after treatment with the Coherent UltraPulse 5000G laser (a pulsed laser; PL) and the Sharplan Silk Touch laser (a continuous-wave laser [CWL] with a flash scanner).

METHODS

Eight patients underwent facial resurfacing treatment on different areas. In each case, one side was treated with the PL and the other with the CWL. The condition of the patients and the treated tissue were monitored periodically after treatment. Histologic assessment of punch biopsies was performed 3 months and 1 year after treatment with hematoxylin-eosin, Masson trichromic, and Verhoeff's stains.

RESULTS

The areas treated with the PL achieved earlier epithelialization with a good appearance. Longer-lasting erythema was observed on the side treated with the CWL. On a histologic level, although the PL-treated tissue epithelialized more quickly, at 3 months and 1 year the collagen was better compacted and better aligned in the CWL-treated tissue, and the macroscopic appearance of the CWL-treated areas was more enhanced.

CONCLUSIONS

The more active vascularization seen in the CWL-treated tissue, associated with the longer-lasting erythema and possibly greater collateral thermal injury, is possibly the reason for the better collagenization and remodeling of collagen and elastin fibers as compared with the results with the PL-treated tissue. This may explain the longer effect associated with CWL treatment. The clinician would do well to bear in mind the histologic findings as well as the macroscopic clinical results when assessing the long-term effects of laser skin resurfacing. (Aesthetic Surg J 2001;21:399-411.).

Hepatitis C virus infection-related morbidity and mortality among patients with human immunodeficiency virus infection

Hepatitis C virus (HCV) has emerged as a major pathogen among patients with human immunodeficiency virus (HIV). Morbidity and mortality were compared among 263 patients with HIV alone, 166 patients with HIV and HCV, and 60 patients with HCV alone (mean duration of follow-up, 2 years and 10 months). No differences in HIV loads and CD4 cells counts were observed between the HIV and HIV/HCV groups. Alanine aminotransferase levels were higher (52 U/L versus 35 U/L; P<.05) and albumin levels were lower (3.5 g/dL versus 3.8 g/dL; P <.02) among coinfected patients than they were among patients with HIV alone. Liver decompensation developed in 10% of patients with HIV/HCV coinfection. In contrast, no liver-related deaths or decompensation occurred in patients without coinfection (P<.05). Of the patients with HIV alone, 7% died, compared with 11% of the coinfected patients (P<.02); 47% of the deaths in the latter group were due to liver-related causes. In summary, HCV infection causes increased morbidity and mortality in patients with HIV infection.

Influence of chronic alcohol abuse on hepatitis C virus replication

BACKGROUND

Patients with alcoholic liver disease have a high prevalence of hepatitis C virus (HCV) infection. Several workers have shown that HCV-infected alcoholics have more severe biochemical and histological evidence of liver disease than anti-HCV-negative patients. One possible mechanism for the increased liver damage is that alcohol may have a stimulatory effect on HCV replication. The present study was carried out to examine this issue in detail.

METHODS

Sixty-eight HCV-infected patients, comprising of 50 chronic alcoholics, consuming 80 g or more of alcohol daily for at least 5 years, and 18 completely abstinent subjects were included in the study. Quantitative HCV-RNA was performed by the branched chain DNA (bDNA) technique.

RESULTS

There was no significant difference in the mean serum HCV titers in chronic alcoholics compared to nonalcoholic subjects. Linear regression analysis showed no correlation between the daily ethanol consumption and HCV titers. Seven of the chronic alcoholics, 4 of whom were continuing to drink and 3 who had become abstinent, were retested after 6 months. There was no definite trend in the viral titers, either in abstinent individuals or in those who continued to drink.

CONCLUSIONS

These findings suggest that chronic alcohol abuse does not influence the HCV load in the serum. Therefore, the observation that alcoholics with HCV infection have more severe liver damage requires some other explanation than increased HCV viral titers.

Treatment of superior vena cava syndrome with recombinant tissue plasminogen activator in a sickle cell patient undergoing bone marrow transplantation

Superior vena cava (SVC) syndrome is a well-recognized clinical entity seen with mediastinal malignancies and intraluminal venous thrombosis. The role of recombinant tissue plasminogen activator (rt-PA) in the resolution of SVC syndrome caused by thrombosis in the bone marrow transplant settings has not been described. The authors report a case of SVC syndrome with good clinical response in a 16-year-old female with sickle cell disease undergoing an allogeneic bone marrow transplant (BMT) from her HLA identical sibling. Shortly after her transplant, she was found to have significant facial edema and swelling above the neck. Concomitantly, her renal function deteriorated with progressive elevation of serum urea nitrogen and creatinine levels, requiring the use of continuous veno-venous hemofiltration. An upper extremity venogram showed complete SVC obstruction (type III) with apparent inferior reflux into the azygos system. rt-PA was started at a dose of (0.5 mg/kg/day) for 2 days. There was a dramatic resolution of her symptoms, including significant improvement in renal function with increase in urine output. A repeat venogram showed free flow from the distal tip of the central line consistent with a patent superior vena cava. There was no evidence of any bleeding manifestations with rt-PA. This report highlights the usefulness of rt-PA as a treatment modality for SVC syndrome in the BMT settings.

Association between increased levels of TNF-alpha, decreased levels of prealbumin and retinol-binding protein, and disease outcome

We determined whether there is an association between tumor necrosis factor-alpha (TNF-alpha), undernutrition [prealbumin (PA) <160 mg/L, retinol binding protein (RBP) <30 mg/L], disease stage, outcome (death or survival), and race in children with leukemia. TNF-alpha, PA, and RBP were measured in 52 patients (0.8 to 17 years old): 18 African Americans, 34 whites; 27 newly diagnosed (ND), and 25 in clinical remission (CR). Mean levels of TNF-alpha were higher in patients than in 46 healthy children (p < 0.05), but were not different between ND and CR groups. Mean acute phase proteins (APP) were different among groups: ND > CR > controls (p < 0.05). Mean levels of PA and RBP were lower in patients than in controls (p < 0.051, and tended to be higher in CR than in ND patients. African-American patients had lower concentrations of TNF-alpha, PA, and RBP but higher APP than white patients (p < 0.05). CR patients and African-American patients who died tended to have higher levels of TNF-alpha and APP, but lower PA and RBP than those who survived. A higher percentage of ND African Americans (45%) than of ND whites (13%) died. Results suggest that undernutrition and inflammation in CR patients and African Americans were associated with poor survival, and that ND African Americans have a poorer outcome than whites independently of TNF-alpha levels.

Software for the competitive edge

In choosing computer software and hardware that will help their agencies run smoothly, providers face a sometimes overwhelming task. One agency shares its success in achieving a competitive edge using "off-the-shelf" software rather than spending money on more expensive, customized solutions.

Characterization of gentamicin-resistant respiratory-deficient (res-) variant strains of Staphylococcus aureus

Exposure of sensitive cells of Staphylococcus aureus to concentrations of gentamicin higher than the minimal inhibitory concentration, results in the recovery of low level resistant strains with a greatly altered phenotype (variants). Because the phenotypic alteration in these strains is so great the expected diagnostic characterization of these variants as S. aureus is obscured. Starting with a genetically-marked parent strain, a comprehensive cytological, physiological, morphological, genetic and biochemical analysis of the variants isolated from it was carried out. The genetic lineage of the variants to the parent was also established by DNA/DNA hybridization. Variants result from mutations in the hemin biosynthesis locus, the effect of which is to disrupt the synthesis of components of the electron transport system, lipid synthesis and selected nucleotide synthesis. Thus the strains are defective in aerobic and anaerobic respiration, (res-), in active transport of aminoglycosides (which confers low level resistance), export of characteristic exo-enzymes, and in cell wall composition and structure.

Rotational diffusion of acetylcholine receptors on cultured rat myotubes

The rotational mobility of acetylcholine receptors (AChR) in the plasma membrane of living rat myotubes in culture is measured in this study by polarized fluorescence recovery after photobleaching (PFRAP). These AChR are known to exist in two distinct classes, evident by labeling with rhodamine alpha-bungarotoxin; clustered AChR that are aggregated in a pattern of highly concentrated speckles and streaks, with each cluster occupying an area of approximately 1,000 microns 2; and nonclustered AChR that appear as diffuse labeling. PFRAP results reported here show that: (a) most clustered AChR (approximately 86%) are rotationally immobile within a time scale of at least several seconds; and (b) most nonclustered AChR (approximately 76%) are rotationally mobile with characteristic times ranging from less than 50 ms to 0.1 s. External cross-linking with the tetravalent lectin concanavalin A immobilizes many nonclustered AChR. PFRAP experiments in the presence of carbachol or cytochalasin D show that the restraints to rotational motion in clusters are remarkably immune to treatments that disperse clusters or disrupt cytoplasmic actin. The experiments also demonstrate the feasibility of using PFRAP to measure rotational diffusion on selected microscopic areas of living nondeoxygenated cells labeled with standard fluorescence probes over a very wide range of time scales, and they also indicate what technical improvements would make PFRAP even more practicable.

Abdominal pain, colomegaly, and jaundice from heart failure related to mitral stenosis

Abdominal manifestations of cardiac disease may result in misleading and erroneous diagnoses. We present a case of congestive heart failure secondary to rheumatic valvular disease resulting in the appearance of an acute surgical abdomen.