Low-dose carboplatin modifies the tumor microenvironment to augment CAR T cell efficacy in human prostate cancer models

Chimeric antigen receptor (CAR) T cells have transformed the treatment landscape for hematological malignancies. However, CAR T cells are less efficient against solid tumors, largely due to poor infiltration resulting from the immunosuppressive nature of the tumor microenvironment (TME). Here, we assessed the efficacy of Lewis Y antigen (LeY)-specific CAR T cells in patient-derived xenograft (PDX) models of prostate cancer. In vitro, LeY CAR T cells directly killed organoids derived from androgen receptor (AR)-positive or AR-null PDXs. In vivo, although LeY CAR T cells alone did not reduce tumor growth, a single prior dose of carboplatin reduced tumor burden. Carboplatin had a pro-inflammatory effect on the TME that facilitated early and durable CAR T cell infiltration, including an altered cancer-associated fibroblast phenotype, enhanced extracellular matrix degradation and re-oriented M1 macrophage differentiation. In a PDX less sensitive to carboplatin, CAR T cell infiltration was dampened; however, a reduction in tumor burden was still observed with increased T cell activation. These findings indicate that carboplatin improves the efficacy of CAR T cell treatment, with the extent of the response dependent on changes induced within the TME.

Mitigating the photocurrent persistence of single ZnO nanowires for low noise photodetection applications

In this work, we investigate the optoelectronic properties of zinc oxide (ZnO) nanowires, which are good candidates for applications based on integrated optics. Single ZnO nanowire photodetectors were fabricated with ohmic contacts. By taking current transient measurements in different atmospheres (oxygen, air, vacuum and argon), and at various temperatures, we point out the importance of surface effects on the electrical behaviour. Results confirm that oxygen chemisorption is responsible for the existence of a high photoconductive gain in these devices, and for the first time a two step process in the photocurrent rise transient is reported. A maximum gain of G = 7.8 × 10⁷ is achieved. However, under certain conditions, the persistence of the photocurrent can last up to several hours and as such may prevent the device from operating at useful rates. From a knowledge of the photocurrent response mechanisms, we establish a method to restore the photodetector to its initial state, with very low dark current, by applying an appropriate gate voltage sequence. This advances the state of the art for these detectors towards commercial applications.

Clinical Case Applications of Mitek® Tissue Anchors in Veterinary Orthopaedics

The Mitek®a tissue anchor is a new device designed for reattaching avulsed tendons, ligaments and joint capsule to bone. This device has proven useful in human orthopaedics. Initially approved for use in Bankart repair (reattachment of glenohumeral ligament to anterior glenoid rim) procedures (1-3), the Mitek® anchor is now utilized in ligamentous repairs and tenodesis of the foot, ankle (4, 5) and wrist (6, 7). These devices have the advantages of biocompatibility, small size, impressive pullout strength, versatility and ease of application (8). In this study Mitek® anchors were used to repair avulsed or ruptured tarsal and phalangeal collateral ligaments, coxofemoral luxations and to provide stability to cruciate deficient stifles.

This paper describes the use of Metek® tissue anchors to repair tendinous, ligamentous, and joint capsule ruptures and avulsions.

Polarisation-controlled single photon emission at high temperatures from InGaN quantum dots

Solid-state single photon sources with polarisation control operating beyond the Peltier cooling barrier of 200 K are desirable for a variety of applications in quantum technology. Using a non-polar InGaN system, we report the successful realisation of single photon emission with a g⁽²⁾(0) of 0.21, a high polarisation degree of 0.80, a fixed polarisation axis determined by the underlying crystallography, and a GHz repetition rate with a radiative lifetime of 357 ps at 220 K in semiconductor quantum dots. The temperature insensitivity of these properties, together with the simple planar epitaxial growth method and absence of complex device geometries, demonstrates that fast single photon emission with polarisation control can be achieved in solid-state quantum dots above the Peltier temperature threshold, making this system a potential candidate for future on-chip applications in integrated systems.

Abstract P6-11-02: Hospitalizations and costs during Implementation of a lay navigation program for older patients with breast cancer in the deep south

Background: Patient-centered strategies are needed to enhance the value of cancer care particularly at the end of life. Lay navigators (LN) can be trained to provide an extra layer of support for cancer patients from diagnosis through survivorship or end of life. We hypothesized that integrating LNs into the care team would reduce healthcare utilization and cost for patients with cancer, including those with breast cancer.

Methods: A prospective, observational study of Medicare claims data was conducted of beneficiaries ≥ 65 years old diagnosed with cancer after 2008 who received care within the UAB Health System Cancer Community Network (12 cancer centers of varying size located in AL, MS, TN, GA, and FL). The first breast cancer (BC) patient was enrolled in navigation in April 2013, and ∼18% of BC patients were navigated by the end of 2014. For this analysis, we report on the subset of patients with BC. The outcomes of interest were calculated per quarter from 2012-2014: (1) the proportion of patients with at least 1 hospitalization, (2) the proportion of the 492 deceased BC patients with a hospitalization in the last 30 and 14 days of life and (3) the Total costs for Medicare, excluding prescription drug costs. We used general linear models to evaluate changes in both health care utilization and cost over time, adjusting for age, sex, cancer stage, phase of care, and navigation group. Differential effects for navigated and non-navigated groups were tested with a group*time interaction. Healthcare utilization estimates are presented as Incidence Rate Ratios (IRR), and costs for Medicare as parameter estimates (β) in terms of dollar amounts.

Results: 4835 BC patients received care from 2012-2014: 622 received navigation services. 14.2 % of navigated BC patients were stage III/IV, compared to 9.33% of non-navigated patients. The proportion of hospitalizations trended downward from 7.9% in quarter 1 (Q1) 2012 to 5.7% in Q4 of 2014 (IRR 0.965, p =0.14), with similar decreases for navigated and non-navigated patients (IRR= 1.00, p > 0.05). Hospitalization in the last 30 days and last 14 days of life were 49.7% and 29.3%, respectively, with no between groups difference. Costs per beneficiary per quarter decreased overall from $4,161 in Q1 2012 to $3,010 in Q4 2014 (p <0.0001). In adjusted analysis, the navigated patients had an average $577 greater decline per quarter than the non-navigated patients (βNavigated=-$636; βnon-Navigated=-$59; p<0.0001).

Conclusions: Medicare costs declined during implementation of a lay navigation program, with greater reductions for navigated patients than non-navigated BC patients. Overall hospitalizations also declined, yet rates remain high for breast cancer patients at the end of life. Integration of LNs should be considered by health systems aiming to transition to value-based healthcare delivery.

The project described was supported by Grant Number 1C1CMS331023 from the Department of Health and Human Services, Centers for Medicare & Medicaid Services. The contents of this abstract are solely the responsibility of the authors and do not necessarily represent the official views of the U.S. Department of Health and Human Services or any of its agencies.

Citation Format: Rocque GB, Kvale EA, Jackson BE, Kenzik K, Lisovicz N, Demark-Wahnefried W, Meneses KM, Taylor RA, Acemgil A, Chambless C, Li Y, Martin M, Fouad M, Pisu M, Partridge EE. Hospitalizations and costs during Implementation of a lay navigation program for older patients with breast cancer in the deep south. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P6-11-02.

Towards witnessing quantum effects in complex molecules

Whether many-body objects like organic molecules can exhibit full quantum behaviour, including entanglement, is an open fundamental question. We present a generic theoretical protocol for entangling two organic molecules, such as dibenzoterrylene in anthracene. The availability of organic dye molecules with two-level energy structures characterised by sharp and intense emission lines are characteristics that position them favourably as candidates for quantum information processing technologies involving single-photons. Quantum entanglement can in principle be generated between several organic molecules by carefully interfering their photoluminescence spectra. Major milestones have been achieved in the last 10 years showcasing entanglement in diverse systems including ions, cold atoms, superconductors, photons, quantum dots and NV-centres in diamond, but not yet in molecules.

Temperature dependence of the radiative recombination time in ZnO nanorods under an external magnetic field of 6 T

The Temperature dependence of the exciton radiative decay time in ZnO nanorods has been investigated, which is associated with the density of states for the intra-relaxation of thermally excited excitons. The photoluminescence decay time was calibrated by using the photoluminescence intensity in order to obtain the radiative decay time. In the absence of an external magnetic field, we have confirmed that the radiative decay time increased with temperature in a similar manner to that seen in bulk material (∼ T1.5). Under an external magnetic field of 6 T parallel to the c-axis, we found that the power coefficient of the radiative decay time with temperature decreased (∼ T1.3) when compared to that in the absence of a magnetic field. This result can be attributed to an enhancement of the effective mass perpendicular to the magnetic field and a redshift of the center-of-mass exciton as a consequence of perturbation effects in the weak-field regime.

Confocal microphotoluminescence mapping of coupled and detuned states in photonic molecules

We study the coupling of cavities defined by the local modulation of the waveguide width using confocal photoluminescence microscopy. We are able to spatially map the profile of the antisymmetric (antibonding) and symmetric (bonding) modes of a pair of strongly coupled cavities (photonic molecule) and follow the coupled cavity system from the strong coupling to the weak coupling regime in the presence of structural disorder. The effect of disorder on this photonic molecule is also investigated numerically with a finite-difference time-domain method and a semi-analytical approach, which enables us to quantify the light localization observed in either cavity as a function of detuning.

Posterior reversible encephalopathy syndrome induced by pazopanib for renal cell carcinoma

WHAT IS KNOWN AND OBJECTIVE

Posterior reversible encephalopathy syndrome (PRES) can be the result of acute hypertension, eclampsia, renal failure and the use of immunosuppressive or cytotoxic agents. We report a case of PRES as a result of the use of pazopanib, a vascular endothelial growth factor inhibitor used for renal cell carcinoma (RCC).

CASE SUMMARY

A 76-year-old man treated with RCC develops PRES shortly after the initiation of pazopanib.

WHAT IS NEW AND CONCLUSION

There are no known reports of the association between PRES and pazopanib. We postulate that pazopanib can disrupt the normal endothelial function of the brain leading to the development of PRES.

Breaking through a roadblock in prostate cancer research: an update on human model systems

Prostate cancer is a prevalent disease that affects the aging male population. Whilst there have been significant advances of our biological understanding of the disease, clinical translation of promising agents continues to lag behind. In part, this is due to a paucity of relevant experimental and pre-clinical models required to further develop effective prevention and therapeutic strategies. Genetically modified cell lines fail to entirely represent the genetic and molecular diversity of primary human specimens, particularly from localised disease. Furthermore, primary prostate cancer tissues are extremely difficult to grow in the laboratory and virtually all human models, whether they grow as xenografts in immune-deficient animals or as cell cultures, are genetically modified by the investigator or derived from patients with advanced metastatic disease. In this review, we discuss the latest advances and improvements to current methods of xenografting human primary prostate cancer, and their potential application to translational research.

Acutely ruptured intracranial saccular aneurysms treated with stent assisted coiling: complications and outcomes in 42 consecutive patients

BACKGROUND

Antiplatelet agents are required to prevent thromboembolic complications from recently deployed intracranial stents, yet they carry a risk of bleeding complications that may be serious in patients with recent subarachnoid hemorrhage.

METHOD

Consecutive patients at a single institution who had ruptured intracranial saccular aneurysms treated with stent assisted coiling were retrospectively reviewed. Our primary outcomes were ischemic stroke related to the stent and bleeding complications possibly related to antithrombotic therapy. Secondary outcomes included 3 month follow-up National Institute of Health Stroke Scale (NIHSS) scores and modified Rankin Scale (mRS) scores.

RESULTS

44 aneurysms in 42 patients were treated. Seven patients experienced ischemic strokes during their hospitalization. Five ischemic strokes were secondary to vasospasm; one was definitely related to thrombus formation within the stent and one was possibly related to the stent. Two patients had asymptomatic intracranial hemorrhages and one patient had a symptomatic intracranial hemorrhage. Patients with Hunt and Hess grades I-II (n=25) experienced no stent associated ischemic strokes or symptomatic intracranial hemorrhages. The two stent associated ischemic strokes and one symptomatic intracranial hemorrhage occurred in patients with Hunt and Hess grades III-V (n=17) and patients with external ventricular drains (EVDs) (n=17). Only one patient had disability at the 3 month follow-up that was possibly related to the stent (mRS score of 3 and NIHSS score of 2).

CONCLUSION

These data suggest that higher grade hemorrhage patients, especially those with EVDs, are at greater risk for ischemic stroke and/or bleeding complications than lower grade patients. However, the complications had a small impact on mid-term disability outcomes in this cohort.

Abnormal photoluminescence properties of GaN nanorods grown on Si(111) by molecular-beam epitaxy

We have studied the photoluminescence properties of GaN nanorods grown on Si(111) substrates by radio-frequency plasma-assisted molecular-beam epitaxy. The hexagonal shaped nanorods with lateral average diameters from 30 to 150 nm are obtained by controlling the Ga flux with a fixed amount of nitrogen. As the diameters decrease, the main emission lines assigned as donor bound excitons are blueshifted, causing a spectral overlap of this emission line with that of the free exciton at 10 K due to the quantum size effect in the GaN nanorods. The temperature-dependent photoluminescence spectra show an abnormal behaviour with an 'S-like' shape for higher diameter nanorods. The activation energy of the free exciton for GaN nanorods with different diameters was also evaluated.

Prostatic tumor stroma: a key player in cancer progression

Although it is evident that prostatic epithelial stem cells are responsible for maintaining normal and malignant tissues, it is well recognized that epithelial cells do not exist independently, but act in concert with the stromal microenvironment. Prostatic stroma is pivotal for normal development and homeostasis. The genetic and morphological changes that occur in prostatic epithelial cells, as they progress from a normal to malignant phenotype, have been well described. However, it is evident that the surrounding microenvironment also plays a major role in cancer cell growth, survival, invasion and metastatic progression. Prostatic tumor stroma provides a niche environment for cancer stem cells and therefore contributes to self-renewal and differentiation. In order to target the tumor microenvironment and develop new therapeutics for prostate cancer, we must understand the role of the tumor stroma, specifically the events mediating the interactions between the cancer stem cell and its immediate microenvironment during cancer initiation and progression. This article presents the rationale and discusses the challenges to targeting prostatic tumor stroma in cancer therapies that will potentially treat prostate cancer.

Towards registered single quantum dot photonic devices

We have registered the position and wavelength of a single InGaAs quantum dot using an innovative cryogenic laser lithography technique. This approach provides accurate marking of the location of self-organized dots and is particularly important for realizing any solid-state cavity quantum electrodynamics scheme where the overlap of the spectral and spatial characteristics of an emitter and a cavity is essential. We demonstrate progress in two key areas towards efficient single quantum dot photonic device implementation. Firstly, we show the registration and reacquisition of a single quantum dot with 50 and 150 nm accuracy, respectively. Secondly, we present data on the successful fabrication of a photonic crystal L3 cavity following the registration process.

Predictors of a true complete response in colorectal liver metastases that disappear radiographically following chemotherapy

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Background: During chemotherapy for colorectal liver metastases (LM), some lesions disappear by CT scan. This may represent a true complete response (CR) with eradication of tumor or a reduced sensitivity of imaging due to chemotherapy induced hepatic steatosis. This study aimed to determine the significance of radiologic disappearance of LM treated with chemotherapy and factors predictive of a true CR. Methods: Between 2000 and 2003, 435 patients evaluated by a hepatobiliary surgeon were treated with neoadjuvant chemotherapy for LM. Inclusion criteria were fewer than 12 LM initially, disappearance of one or more LM by CT scan and a clinical follow-up of at least 1 year after disappearance. A pathologic CR (pCR) was defined as the absence of a LM in the resected specimen, a durable clinical CR (cCR) was defined as a LM that did not reappear during follow-up imaging. A LM was defined as found if it was detected by other imaging (MRI), at resection, or if it recurred during follow-up. LM that were found were compared to pCR and durable cCR to determine factors predictive of a true CR. Results: During chemotherapy, 39 (9%) patients had a total of 117 LM disappear by follow-up CT scan. The outcome is shown in the Table . Treatment with hepatic arterial infusion (HAI) chemotherapy (n=22) was associated with a significantly higher rate of pCR or durable cCR (42% vs. 14%, p<0.001). LM were also significantly more likely to represent a pCR or durable cCR when the surrounding liver did not demonstrate steatosis (p<0.001), when the patient’s BMI was <30 kg/m2 (p=0.002), and when a preoperative MRI was performed (p=0.01). Conclusions: Among disappearing LM, a pCR occurs in 37% and a durable cCR in 26%, yielding a true CR rate of 63%. The disappearing LM in patients treated with HAI chemotherapy were more likely to a represent true CR when compared to systemic chemotherapy alone. Hepatic steatosis and obesity impaired the ability to detect lesions by CT scan and MRI improved the preoperative detection rate of disappearing LM.

[Table: see text]

No significant financial relationships to disclose.

Safety and feasibility of intra-arterial nicardipine for the treatment of subarachnoid hemorrhage-associated vasospasm: initial clinical experience with high-dose infusions

BACKGROUND AND PURPOSE

Delayed cerebral ischemia from vasospasm is a major complication after aneurysmal subarachnoid hemorrhage (SAH), but complications and/or low efficacy are associated with current therapy. We report our initial experience with intra-arterial use of a calcium channel blocker, nicardipine.

MATERIALS AND METHODS

A retrospective review of a consecutive series of patients with clinical and angiographic vasospasm treated with intra-arterial nicardipine was performed. Standard criteria for definition of significant, intractable vasospasm after aneurysmal SAH were used. After catheter angiographic confirmation of vasospasm, arteries showing severe narrowing were targeted for superselective catheterization. Nicardipine was infused at a high dose rate (0.415-0.81 mg/min). Contrast injections were performed at 2-5-mg intervals to assess effective response (a 60% increase in arterial diameter of the most severely decreased in caliber vessel compared with the very first angiographic run).

RESULTS

Eleven consecutive patients underwent a total of 20 procedures; most had SAH with high Hunt and Hess grades (III or IV). All had depressed level of consciousness; others had paresis (7/20, 35%), aphasia (1/20, 5%), and facial nerve palsy (1/20, 5%). Between 10 and 40 mg of nicardipine was used. A 60% increase in diameter of the main affected artery compared with the initial diameter measured in the initial angiographic run was achieved in all procedures. Clinical improvement (resolved focal symptoms or increased Glasgow Coma Score) occurred in 10 of 11 patients (91%). One patient died from complications of the initial hemorrhage. No complications occurred after 16 of 20 procedures (80%); minor complications without sequelae occurred after the remaining procedures. Follow-up of at least 2 months in 10 survivors revealed minor or no deficits in most patients with a Glasgow Outcome Score of 1 or 2 in 9 of 10 patients (90%).

CONCLUSION

In this small series, high-dose intra-arterial nicardipine infusion to treat SAH-associated vasospasm seems to be safe and effective.

17beta-estradiol induces apoptosis in the developing rodent prostate independently of ERalpha or ERbeta

Estrogens induce both proliferative and antiproliferative responses in the prostate gland. To date, antiproliferative effects of estrogens are generally considered to be due to systemic antiandrogenic actions. However, estrogen action mediated through estrogen receptor (ER) beta was recently suggested as another mechanism of induction of apoptosis in the prostate. This study aimed to explore the hypothesis that the antiproliferative effects of estrogen are directly mediated through ERbeta using a prostate organ culture system. We previously reported effects of 17beta-estradiol (E2) using rat ventral prostate (VP) tissues, and adapted the system for culturing mouse tissues. In both rat and mouse models, estrogen-induced apoptosis was detected that was spatially and regionally localized to the epithelium of the distal tips. Using organ cultures of alphaER knockout (alphaERKO) and betaERKO prostates, we failed to demonstrate that apoptosis induced by E2 was mediated through either receptor subtype. Activation of ER-selective ligands (ERalpha, propyl pyrazole triol, ERbeta, diaryl-proprionitrile, and 5alpha-androstane-3beta,17beta-diol) in organ culture experiments failed to induce apoptosis, as did the membrane impermeable conjugate E2:BSA, discounting the possibility of nongenomic effects. Consequently, E2 regulation of androgen receptor (AR) expression was examined and, in the presence of nanomolar testosterone levels, E2 caused a specific reduction in AR protein expression in wild-type, alphaERKO, and betaERKO mice, particularly in the distal region where apoptosis was detected. This down-regulation of AR protein provides a possible mechanism for the proapoptotic action of E2 that is independent of ERs or nongenomic effects.

Early prostate development and its association with late-life prostate disease

The development of the prostate is an emerging priority area for prostate biologists. Early changes in prostate development permanently alter prostate morphology and function and an understanding of the permanent nature of early events that may influence the onset of late-life disease is vital. Two of the inherent problems involve associating exposure in early life with outcome in late life or maturity and accounting for the influence of genetic, environmental, dietary or metabolic factors during the intervening period. Any one of these factors, alone or in combination, might lead to an explanation of the discrepancies found in the literature regarding the influence of early changes to the prostate in later life. Therefore, it is important to establish a causal link between the hormonal changes that occur during the fetal/neonatal period and that imprint the gland and the onset of late-life pathology. In order to achieve this goal, several technical challenges need to be overcome to permit the objective assessment of prostate branching morphogenesis. Stereological techniques now allow the quantification of several parameters of branching morphogenesis and the identification of specific early changes that are permanent and irreversible with a late-life outcome. This methodology provides the means to determine the action of a range of genes or hormone/growth factors that have been implicated in prostate development and disease.

Nanoscale solid-state quantum computing

Most experts agree that it is too early to say how quantum computers will eventually be built, and several nanoscale solid-state schemes are being implemented in a range of materials. Nanofabricated quantum dots can be made in designer configurations, with established technology for controlling interactions and for reading out results. Epitaxial quantum dots can be grown in vertical arrays in semiconductors, and ultrafast optical techniques are available for controlling and measuring their excitations. Single-walled carbon nanotubes can be used for molecular self-assembly of endohedral fullerenes, which can embody quantum information in the electron spin. The challenges of individual addressing in such tiny structures could rapidly become intractable with increasing numbers of qubits, but these schemes are amenable to global addressing methods for computation.

A case of anaemia in a neonatal warthog (Phacochoerus aethiopicus) and evaluation of serum-soluble iron in warthogs

A 38-day-old male warthog (Phacochoerus aethiopicus) with marked anaemia (haematocrit = 14 %) presented to the Denver Zoological Gardens hospital with ataxia, tachypnoea, suspected stunted growth and cardiomegaly. The piglet demonstrated some features consistent with both iron deficiency anaemia and autoimmune haemolytic anaemia. Serum-soluble iron was below the level of detection (< 8.96 micromol/l). Iron deficiency anaemia is a well recognised entity in domestic swine reared on concrete and denied access to soil. Fifteen captive warthogs were subsequently evaluated for serum soluble iron content (mean = 21.62 +/- 4.36 micromol/l as well as 5 neonatal warthog piglets that required hand-rearing. Only 1 of 5 neonatal warthog piglets had measurable serum soluble iron (9.50 micromol/l). These data suggest that warthogs are similar to domestic swine and are born with low iron stores. Some form of iron supplementation should be considered for captive neonatal warthog piglets, especially if they are reared on concrete.

KANADI regulates organ polarity in Arabidopsis

Leaves and floral organs are polarized along their adaxial-abaxial (dorsal-ventral) axis. In Arabidopsis, this difference is particularly obvious in the first two rosette leaves, which possess trichomes (leaf hairs) on their adaxial surface but not their abaxial surface. Mutant alleles of KANADI (KAN) were identified in a screen for mutants that produce abaxial trichomes on these first two leaves. kan mutations were originally identified as enhancers of the mutant floral phenotype of crabs claw (crc), a gene that specifies abaxial identity in carpels. Here we show that KAN is required for abaxial identity in both leaves and carpels, and encodes a nuclear-localized protein in the GARP family of putative transcription factors. The expression pattern of KAN messenger RNA and the effect of ectopically expressing KAN under the regulation of the cauliflower mosaic virus (CAMV) 35S promoter indicate that KAN may also specify peripheral identity in the developing embryo.

Mutational analysis of metallo-beta-lactamase CcrA from Bacteroides fragilis

In an effort to evaluate the roles of Lys184, Asn193, and Asp103 in the binding and catalysis of metallo-beta-lactamase CcrA from Bacteroides fragilis, site-directed mutants of CcrA were generated and characterized using metal analyses, CD spectroscopy, and kinetic studies. Three Lys184 mutants were generated where the lysine was replaced with alanine, leucine, and glutamate, and the analysis of these mutants indicates that Lys184 is not greatly involved in binding of cephalosporins to CcrA; however, this residue does have a significant role in binding of penicillin G. Three Asn193 mutants were generated where the asparagine was replaced with alanine, leucine, and aspartate, and these mutants exhibited <4-fold decrease in k(cat), suggesting that Asn193 does not play a large role in catalysis. However, stopped-flow visible kinetic studies showed that the Asn193 mutants exhibit a slower substrate decay rate and no change in the product formation rate as compared with wild-type CcrA. These results support the proposed role of Asn193 in interacting with and activating substrate during catalysis. Two Asp103 mutants were generated where the aspartate was replaced with serine and cysteine. The D103C and D103S mutants bind the same amount of Zn(II) as wild-type CcrA and exhibited a 10(2)-fold and 10(5)-fold decrease in activity, respectively. Results from solvent isotope, proton inventory, and rapid-scanning visible studies suggest that Asp103 plays a role in generating the enzyme intermediate but does not donate a proton to the enzyme intermediate during the rate-limiting step of the catalytic mechanism.

Symptomatic pulmonary hyalinizing granuloma

An otherwise healthy 37-year-old man came to the emergency room with left-sided dull chest pain of 4 weeks' duration. Physical examination, laboratory studies, and electrocardiogram were all unremarkable. A chest x-ray film revealed calcified pulmonary nodules. Computed tomography of the chest confirmed bilateral parenchymal cavitary lesions. Via limited thoracotomy, a tan nodule measuring 2.5 to 3.0 cm in diameter was excised from the left upper lobe. Histopathologic examination revealed a well circumscribed lesion and extensive lamellar hyalinization. A few foci of finely granular calcification were present within the hyalinizing areas. After surgery and short-term use of nonnarcotic analgesics, the chest pain resolved. Although pulmonary hyalinizing granuloma (PHG) is known to produce cavitating lesions, calcification at multiple sites is also consistent with this diagnosis. Clinicians should remember to include PHG in the differential diagnosis of multiple pulmonary nodules.

Knee position error detection in closed and open kinetic chain tasks during concurrent cognitive distraction

It is important to establish whether presumed differences among varieties of motor responses are manifested in related differences in performance. In order to determine possible functional distinctions between closed and open kinetic chain tasks, participants' performance in the presence or absence of cognitive distraction on an error-detection task was assessed. Individual testing of participants consisted of knee extension and flexion movements to experimenter-defined positions, approximating the 25th, 50th, and 75th percentile of the participants' range of motion on the apparatus. Performance under conditions of distraction was significantly worse than in the absence of distraction. Performance using longer movements was significantly more accurate. No substantial differences were found between closed and open kinetic chain movements. Limitations of this research for the distinction between open and closed chain tasks are addressed, and clinical implications of the effects of distraction are presented.

A Comparison of Surgical Training with Live Anesthetized Dogs and Cadavers

Cadavers were compared with live anesthetized dogs for their effectiveness as models for surgical training of veterinary medical students. One group of students was trained using cadavers, and a peer group was trained using live anesthetized dogs. Both groups then performed an intestinal anastomosis using a live subject. The time to completion of the procedure was recorded. The anastomoses and celiotomy closures were evaluated. Each anastomosis was isolated and pressure tested. Reviewers blindly scored each surgical team's performance based on actual inspection of the surgical site and on viewing videotapes of the procedure. The participants' attitudes toward the use of live animals in teaching and research were documented before and after training. No statistically significant differences could be detected between the two groups. The results suggest that some substitution of cadavers for live dogs in surgical training might be feasible.

The transition from maternal to embryonic control in the 2-cell mouse embryo

The development of the early 2-cell mouse embryo to the late 2-cell stage is marked by the appearance between 23 and 26 h post-insemination of a complex of polypeptides of mol. wt. approximately 67 K. Addition of alpha-amanitin between 18 and 21 h post-insemination prevents or reduces the subsequent appearance of these polypeptides. Addition of alpha-amanitin after 21 h does not obviously affect the appearance of the approximately 67 K polypeptides. A major change in synthetic profile occurs between 29 and 32 h post-insemination involving many polypeptides. Addition of alpha-amanitin to 2-cell embryos prior to 29 h post-insemination prevents the appearance of the new polypeptides observed during this major change but does not prevent the disappearance of the old polypeptides. In contrast, addition of alpha-amanitin after this time does not affect the appearance of the new polypeptides. This result, together with other evidence presented, suggests that during the 2-cell stage the embryonic genome shows transcriptional activity in two phases at 18-21 and 26-29 h post-insemination, that these transcripts are utilized soon after their synthesis, and that most maternal transcripts used before the second phase of embryonic transcription become ineffective soon afterwards.

Mesothelioma: current perspectives

Thirty patients with the diagnosis of mesothelioma were admitted to the Swedish Hospital Medical Center, Seattle, from 1975 to 1979. Of these, 26 had pleural and 4 had peritoneal mesothelioma. In 20 of the patients with pleural mesothelioma, the diagnosis had been made by open thoractomy and in only one by needle biopsy of the pleura. The average survival of the patients with pleural tumors from time of diagnosis was 15 months, and two are alive at three and eight months, respectively, one of whom had an apparent solitary benign mesothelioma. The average survival of those with peritoneal mesothelioma was ten months, although one has survived six years. There were 17 patients with a known history of exposure to asbestos, 14 while working in shipyards. Because of the relatively high incidence of this previously rare tumor in the Puget Sound, Washington, area, and the generally dismal results of therapy, better methods of diagnosis including thoracoscopy and a more systematic approach to treatment are recommended.

Linkage and gene localization of hereditary spherocytosis (HS)

Fifteen kindreds with dominant hereditary spherocytosis (HS) were studied. Expansion of the data from a family with an 8/12 translocation provided further evidence that at least one locus for HS is located near the breakpoint of the translocation. Linkage analysis of all families showed a lack of linkage with all marker loci studied except for Gm (IgG). Linkage between Gm and HS was shown to be significant with a maximum lod score of 3.42 at a recombination fraction of 22%. No heterogeneity of the recombination fraction was observed either between sexes or between families. These results are compatible with the hypothesis that HS is not a heterogeneous disorder.

Estrogens in food: the almond mystery

Studies were made of 36 different nuts, grains, fruits and vegetables commonly used as human foods; each of these was fed to a group of ovariectomized rats for 10 days as a sole diet. The estrogenic activities of the foods were estimated by comparing the uterine weights, uterine fluid volumes and the vaginal cornification indices of each group of rats with those of groups fed other foods. Almonds, cashew nuts, peanuts, oats, corn, wheat and apples all showed estrogenic activity. The original sample of almonds showed the greatest estrogenic activity (p less than 0.01) which was confirmed by repetition of the experiment (p less than 0.01), but subsequent studies of other samples of almonds showed no estrogenic activity. Possible reasons for the disparity of the results with different lots of almonds are discussed.

Aggregation, migration and population mechanics

A concept is developed for the regulation of populations by density-dependent movement, rather than by overt competition alone. Fitness is seen as maximising the reproductive advantage of a balance between migratory and congregatory behaviours. Population density is shown to be spatially, as well as temporally dynamic and a mechanism is proposed that accounts for observed spatial behaviour.