AuDrA: An automated drawing assessment platform for evaluating creativity

The visual modality is central to both reception and expression of human creativity. Creativity assessment paradigms, such as structured drawing tasks Barbot (2018), seek to characterize this key modality of creative ideation. However, visual creativity assessment paradigms often rely on cohorts of expert or naïve raters to gauge the level of creativity of the outputs. This comes at the cost of substantial human investment in both time and labor. To address these issues, recent work has leveraged the power of machine learning techniques to automatically extract creativity scores in the verbal domain (e.g., SemDis; Beaty & Johnson 2021). Yet, a comparably well-vetted solution for the assessment of visual creativity is missing. Here, we introduce AuDrA - an Automated Drawing Assessment platform to extract visual creativity scores from simple drawing productions. Using a collection of line drawings and human creativity ratings, we trained AuDrA and tested its generalizability to untrained drawing sets, raters, and tasks. Across four datasets, nearly 60 raters, and over 13,000 drawings, we found AuDrA scores to be highly correlated with human creativity ratings for new drawings on the same drawing task (r = .65 to .81; mean = .76). Importantly, correlations between AuDrA scores and human raters surpassed those between drawings' elaboration (i.e., ink on the page) and human creativity raters, suggesting that AuDrA is sensitive to features of drawings beyond simple degree of complexity. We discuss future directions, limitations, and link the trained AuDrA model and a tutorial ( https://osf.io/kqn9v/ ) to enable researchers to efficiently assess new drawings.

Divergent semantic integration (DSI): Extracting creativity from narratives with distributional semantic modeling

We developed a novel conceptualization of one component of creativity in narratives by integrating creativity theory and distributional semantics theory. We termed the new construct divergent semantic integration (DSI), defined as the extent to which a narrative connects divergent ideas. Across nine studies, 27 different narrative prompts, and over 3500 short narratives, we compared six models of DSI that varied in their computational architecture. The best-performing model employed Bidirectional Encoder Representations from Transformers (BERT), which generates context-dependent numerical representations of words (i.e., embeddings). BERT DSI scores demonstrated impressive predictive power, explaining up to 72% of the variance in human creativity ratings, even approaching human inter-rater reliability for some tasks. BERT DSI scores showed equivalently high predictive power for expert and nonexpert human ratings of creativity in narratives. Critically, DSI scores generalized across ethnicity and English language proficiency, including individuals identifying as Hispanic and L2 English speakers. The integration of creativity and distributional semantics theory has substantial potential to generate novel hypotheses about creativity and novel operationalizations of its underlying processes and components. To facilitate new discoveries across diverse disciplines, we provide a tutorial with code (osf.io/ath2s) on how to compute DSI and a web app ( osf.io/ath2s ) to freely retrieve DSI scores.

Primary thoracic intramedullary spinal cord tumor with likely metastases of glial origin to the lumbosacral vertebrae: Illustrative case

Background

Metastasis of systemic neoplasms to the spine is common; however, the metastasis of primary spinal cord tumors to other regions in the body is an infrequent occurrence. A few case reports have described the metastasis of primary spinal cord tumors, and in most cases, patients were younger than 30 years of age.

Case Description

We present an illustrative case of a 47-year-old female with metastatic lesions to the lumbosacral vertebrae years after the initial diagnosis of an intradural, intramedullary spinal cord tumor (IMSCT). Although the surgical biopsy of the IMSCT was nondiagnostic, the patient was not found to have a separate primary neoplastic source, and the specimens of the metastatic lesions from the lumbar vertebral body were of glial origin.

Conclusion

Metastasis from primary IMSCTs is extremely rare. Distant vertebral body and intracranial metastasis are even rarer yet possible. The clinical course is highly aggressive and responds poorly to current standard treatment.

Magnetic Resonance-Guided Stereotaxy for Infusions to the Pig Brain

The overall goal of this procedure is to perform stereotaxy in the pig brain with real-time magnetic resonance (MR) visualization guidance to provide precise infusions. The subject was positioned prone in the MR bore for optimal access to the top of the skull with the torso raised, the neck flexed, and the head inclined downward. Two anchor pins anchored on the bilateral zygoma held the head steady using the head holder. A magnetic resonance imaging (MRI) flex-coil was placed rostrally across the head holder so that the skull was accessible for the intervention procedure. A planning grid placed on the scalp was used to determine the appropriate entry point of the cannula. The stereotactic frame was secured and aligned iteratively through software projection until the projected radial error was less than 0.5 mm. A hand drill was used to create a burr hole for insertion of the cannula. A gadolinium-enhanced co-infusion was used to visualize the infusion of a cell suspension. Repeated T1-weighted MRI scans were registered in real time during the agent delivery process to visualize the volume of gadolinium distribution. MRI-guided stereotaxy allows for precise and controlled infusion into the pig brain, with concurrent monitoring of cannula insertion accuracy and determination of the agent volume of distribution.

Leptomeningeal metastasis from neuroendocrine carcinoma of the cervix: illustrative case

BACKGROUND

Leptomeningeal carcinomatosis is a rare feature of metastasis that is characterized by thickening and increased contrast enhancement throughout the meninges of the central nervous system (CNS). Leptomeningeal disease (LMD) can occur as spread from primary CNS tumors or as a manifestation of metastasis to the CNS from primary tumor sites outside the CNS. Leptomeningeal disease is, however, rare in cervical cancer, in which metastasis occurs typically from local invasion.

OBSERVATIONS

The authors discuss the case of CNS metastasis with LMD from the rare neuroendocrine carcinoma of the cervix (NECC). Cervical cancer infrequently metastasizes to the CNS, but NECC is an aggressive variant with greater metastatic potential. Many of these patients will have previously received pelvic radiation, limiting their candidacy for craniospinal radiation for LMD treatment due to field overlap. This illustrative case documents the first known case of NECC CNS metastasis accompanied by LMD treated with intrathecal chemotherapy.

LESSONS

Reported is the first known case of NECC with CNS metastasis accompanied by LMD. The authors highlight the potentially critical role of intrathecal chemotherapy, in addition to radiotherapy, in treating leptomeningeal metastasis from cervical cancer.

Do basic auscultation skills need to be resuscitated? A new strategy for improving competency among nursing students

BACKGROUND

Auscultation of heart and lung sounds is a foundational competency for Registered Nurses (RNs). Precise and timely assessments are important for the early detection and recognition of the deteriorating patient. Studies have shown that improved teaching methods that incorporate emerging technologies and address different learning styles are needed to improve competency in auscultation.

METHOD

Undergraduate nursing students (n = 127) were randomized into treatment and control groups. The control group received the usual preparation in auscultation learning strategies. The treatment group received the usual training plus three auscultation learning sessions that were each 2 h in length (cardiac, pulmonary and mixed sounds).

RESULTS

The virtual auscultation teaching strategy had a significant impact on undergraduate nursing student's competency in recognizing heart murmurs. The treatment group also had increased scores compared to the control group increased scores in distinguishing normal versus abnormal heart and lung sounds, identification of crackles and diminished breath sounds.

CONCLUSION

Virtual auscultation as a teaching strategy was shown to have a positive impact on undergraduate student nurse competence in accurately identifying heart and lung sounds.

Neurosurgical management of perineural metastases: A case series and review of the literature

Background:

Perineural invasion (PNI) and spread are one of the grimmest prognostic factors associated with primary skin and head-and-neck cancers, yet remain an often confused, and underreported, phenomenon. Adding complexity to reaching a diagnosis and treating perineural spread (PNS) is the finding that patients may have no known primary tumor, history of skin cancer, and/or incidental PNI in the primary tumor. These delays in diagnosis and treatment are further compounded by an already slow disease process and often require multidisciplinary care with combinations of stereotactic radiosurgery, surgical resection, and novel treatments such as checkpoint inhibitors.

Methods:

Six patients with metastatic cancer to the cranial nerves who underwent Gamma Knife radiosurgery (GKRS) treatment were chosen for retrospective analysis. This information included age, gender, any past surgeries (both stereotactic and regular surgery), dose of radiation and volume of the tumor treated in the GKRS, date of PNS, comorbidities, the patient follow-up, and pre- and post-GKRS imaging. The goal of the follow-up with radiographing imaging was to assess the efficacy of GKSS.

Results:

The clinical course of six patients with PNS is presented. Patients followed variable courses with mixed outcomes: two patients remain living, one was lost to follow-up, and three expired with a median survival of 12 months from date of diagnosis. Patients at our institution are ideally followed for life.

Conclusion:

Given the morbidity and mortality of PNS of cancer, time is limited, and further understanding is required to improve outcomes. Here, we provide a case series of patients with PNS treated with stereotactic radiosurgery, discuss their clinical courses, and review the known literature.

CAR T Cell Therapy for Pediatric Brain Tumors

Chimeric Antigen Receptor (CAR) T cell therapy has recently begun to be used for solid tumors such as glioblastoma multiforme. Many children with pediatric malignant brain tumors develop extensive long-term morbidity of intensive multimodal curative treatment. Others with certain diagnoses and relapsed disease continue to have limited therapies and a dismal prognosis. Novel treatments such as CAR T cells could potentially improve outcomes and ameliorate the toxicity of current treatment. In this review, we discuss the potential of using CAR therapy for pediatric brain tumors. The emerging insights on the molecular subtypes and tumor microenvironment of these tumors provide avenues to devise strategies for CAR T cell therapy. Unique characteristics of these brain tumors, such as location and associated morbid treatment induced neuro-inflammation, are novel challenges not commonly encountered in adult brain tumors. Despite these considerations, CAR T cell therapy has the potential to be integrated into treatment schema for aggressive pediatric malignant brain tumors in the future.

A Glioblastoma Genomics Primer for Clinicians

New discoveries in Glioblastoma (GBM) biology have been made using genomics data. Genomic markers are routinely integrated into clinical neurosurgical practice. In this manuscript, we review the fundamentals of genomics such as the differences between first, second, and third generation sequencing technology. We also review the impact of single cell genomics in understanding the complex heterogenous GBM microenvironment. Finally, we will discuss advances in epigenetics that have lent insights into treatment resistance. The integration of genomics into neuro-oncology clinical practice is routine and will continue to expand with the expansion of precision of medicine. We provide a primer for clinicians.

Continuous Developmental and Early Life Trichloroethylene Exposure Promoted DNA Methylation Alterations in Polycomb Protein Binding Sites in Effector/Memory CD4+ T Cells

Trichloroethylene (TCE) is an industrial solvent and drinking water pollutant associated with CD4⁺ T cell-mediated autoimmunity. In our mouse model, discontinuation of TCE exposure during adulthood after developmental exposure did not prevent immunotoxicity. To determine whether persistent effects were linked to epigenetic changes we conducted whole genome reduced representation bisulfite sequencing (RRBS) to evaluate methylation of CpG sites in autosomal chromosomes in activated effector/memory CD4⁺ T cells. Female MRL+/+ mice were exposed to vehicle control or TCE in the drinking water from gestation until ~37 weeks of age [postnatal day (PND) 259]. In a subset of mice, TCE exposure was discontinued at ~22 weeks of age (PND 154). At PND 259, RRBS assessment revealed more global methylation changes in the continuous exposure group vs. the discontinuous exposure group. A majority of the differentially methylated CpG regions (DMRs) across promoters, islands, and regulatory elements were hypermethylated (~90%). However, continuous developmental TCE exposure altered the methylation of 274 CpG sites in promoters and CpG islands. In contrast, only 4 CpG island regions were differentially methylated (hypermethylated) in the discontinuous group. Interestingly, 2 of these 4 sites were also hypermethylated in the continuous exposure group, and both of these island regions are associated with lysine 27 on histone H3 (H3K27) involved in polycomb complex-dependent transcriptional repression via H3K27 tri-methylation. CpG sites were overlapped with the Open Regulatory Annotation database. Unlike the discontinuous group, continuous TCE treatment resulted in 129 DMRs including 12 unique transcription factors and regulatory elements; 80% of which were enriched for one or more polycomb group (PcG) protein binding regions (i.e., SUZ12, EZH2, JARID2, and MTF2). Pathway analysis of the DMRs indicated that TCE primarily altered the methylation of genes associated with regulation of cellular metabolism and cell signaling. The results demonstrated that continuous developmental exposure to TCE differentially methylated binding sites of PcG proteins in effector/memory CD4⁺ cells. There were minimal yet potentially biologically significant effects that occurred when exposure was discontinued. These results point toward a novel mechanism by which chronic developmental TCE exposure may alter terminally differentiated CD4⁺ T cell function in adulthood.

SMARC-B1 deficient sinonasal carcinoma metastasis to the brain with next generation sequencing data: a case report of perineural invasion progressing to leptomeningeal invasion

BACKGROUND

SMARCB1-deficient sinonasal carcinoma (SDSC) is an aggressive subtype of head and neck cancers that has a poor prognosis despite multimodal therapy. We present a unique case with next generation sequencing data of a patient who had SDSC with perineural invasion to the trigeminal nerve that progressed to a brain metastasis and eventually leptomeningeal spread.

CASE PRESENTATION

A 42 year old female presented with facial pain and had resection of a tumor along the V2 division of the trigeminal nerve on the right. She underwent adjuvant stereotactic radiation. She developed further neurological symptoms and imaging demonstrated the tumor had infiltrated into the cavernous sinus as well as intradurally. She had surgical resection for removal of her brain metastasis and decompression of the cavernous sinus. Following her second surgery, she had adjuvant radiation and chemotherapy. Several months later she had quadriparesis and imaging was consistent with leptomeningeal spread. She underwent palliative radiation and ultimately transitioned quickly to comfort care and expired. Overall survival from time of diagnosis was 13 months. Next generation sequencing was carried out on her primary tumor and brain metastasis. The brain metastatic tissue had an increased tumor mutational burden in comparison to the primary.

CONCLUSIONS

This is the first report of SDSC with perineural invasion progressing to leptomeningeal carcinomatosis. Continued next generation sequencing of the primary and metastatic tissue by clinicians is encouraged toprovide further insights into metastatic progression of rare solid tumors.

Developmental exposure to environmental toxicant trichloroethylene alters DNA methylation in polycomb protein binding regions in effector/memory CD4 + T cells from autoimmune-prone mice

Trichloroethylene (TCE) is an industrial solvent and drinking water pollutant associated with autoimmunity in human populations. Previous studies in autoimmune-prone MRL+/+ mice revealed autoimmune pathology and CD4 + T cell autoreactivity were more robust when exposure occurred during development rather than adulthood. To determine whether these effects were linked to epigenetic changes, mice were exposed to vehicle control or TCE in the drinking water beginning at gestation until 37 weeks of age. In some mice, TCE was removed from drinking water at 22 weeks of age. Whole genome reduced representation bisulfite sequencing (RRBS) was used to compare methylation of CpG sites in autosomal chromosomes in effector/memory CD4+ T cells. Few significant changes occurred in mice when TCE was removed from drinking water. In contrast, continuous developmental TCE exposure revealed differential methylation of 252 CpG sites relative to controls. When CpG sites were overlapped with the Open Regulatory Annotation database (ORegAnno), continuous TCE treatment resulted in 130 differentially methylated regions (DMRs) that included 12 unique transcription factors. Interestingly, 80% of DMRs occurred in areas known to bind Polycomb group (PcG) proteins that form the polycomb-repressive complex 2 (PRC2) in mammalian cells, namely, SUZ12, EZH2, JARID2, and MTF2. Pathway analysis of the DMRs indicated that TCE primarily altered the methylation of genes asociated with regulation of cellular metabolism and cell signaling pathways. In summary, TCE differentially methylated binding sites of PcG proteins in effector/memory CD4+ cells, and point toward a novel mechanism by which TCE could modulate CD4 + T cell function and promote autoimmunity.

Silodosin inhibits prostate cancer cell growth via ELK1 inactivation and enhances the cytotoxic activity of gemcitabine

BACKGROUND

Biological significance of ELK1, a transcriptional factor whose phosphorylation is necessary for c-fos proto-oncogene activation, in prostate cancer remains far from fully understood. In this study, we aim to investigate the role of ELK1 in tumor growth as well as the efficacy of a selective α1A-adrenergic blocker, silodosin, in ELK1 activity in prostate cancer cells.

METHODS

We first immunohistochemically determined the levels of phospho-ELK1 (p-ELK1) expression in radical prostatectomy specimens. We then assessed the effects of ELK1 knockdown via short hairpin RNA and silodosin on cell proliferation, migration, and invasion in prostate cancer lines.

RESULTS

The levels of p-ELK1 expression were significantly higher in carcinoma than in benign (P < 0.001) or high-grade prostatic intraepithelial neoplasia (HGPIN) (P = 0.002) as well as in HGPIN than in benign (P < 0.001). Kaplan-Meier and log-rank tests revealed that moderate-strong positivity of p-ELK1 in carcinomas tended to correlate with biochemical recurrence after radical prostatectomy (P = 0.098). In PC3 and DU145 expressing ELK1 (mRNA/protein) but no androgen receptor (AR), ELK1 silencing resulted in considerable decreases in the expression of c-fos as well as in cell migration/invasion and matrix metalloproteinase-2 expression, but not in cell viability. Silodosin treatment reduced the expression/activity of ELK1 in these cells as well as the viability of AR-positive LNCaP and C4-2 cells and the migration of both AR-positive and AR-negative cells, but not the viability of AR-negative or ELK1-negative cells. Interestingly, silodosin significantly increased sensitivity to gemcitabine, but not to cisplatin or docetaxel, even in AR-negative cells.

CONCLUSIONS

ELK1 is likely to be activated in prostate cancer cells and promote tumor progression. Furthermore, silodosin that inactivates ELK1 in prostate cancer cells not only inhibits their growth but also enhances the cytotoxic activity of gemcitabine. Thus, ELK1 inhibition has the potential of being a therapeutic approach for prostate cancer.

Silodosin inhibits the growth of bladder cancer cells and enhances the cytotoxic activity of cisplatin via ELK1 inactivation

Silodosin, a selective α1A-adrenergic blocker prescribed for the symptomatic treatment of benign prostatic hyperplasia, was previously shown to decrease the expression of ELK1, a c-fos proto-oncogene regulator and a well-described downstream target of the PKC/Raf-1/ERK pathway, in human prostate smooth muscle cells. PKC/Raf-1/ERK activation has also been implicated in drug resistance. In the current study, we assessed the effects of silodosin on ELK1 expression/activity in bladder cancer cells as well as on their proliferation in the presence or absence of chemotherapeutic drugs, including cisplatin and gemcitabine. In bladder cancer cell lines, silodosin reduced the expression of ELK1 (mRNA/protein) and its downstream target, c-fos gene, as well as the transcriptional activity of ELK1. While silodosin alone (up to 10 μM) insignificantly affected the growth of bladder cancer cells cultured in androgen depleted conditions or those expressing ELK1-short hairpin RNA, it considerably inhibited the viability of androgen receptor (AR)-positive/ELK1-positive cells in the presence of androgens. Silodosin also inhibited the migration of ELK1-positive cells with or without a functional AR, but not that of ELK1 knockdown cells. Interestingly, silodosin treatment or ELK1 silencing resulted in increases in drug sensitivity to cisplatin, but not to gemcitabine, even in AR-negative cells or AR-positive cells cultured in an androgen-depleted condition. In addition, silodosin decreased the expression of NF-κB, a key regulator of chemoresistance, and its transcriptional activity. Moreover, immunohistochemistry in bladder cancer specimens from patients who received neoadjuvant chemotherapy revealed that phospho-ELK1 positivity strongly correlated with chemoresistance. Silodosin was thus found to not only inhibit cell viability and migration but also enhance the cytotoxic activity of cisplatin in bladder cancer lines via inactivating ELK1. Our results suggest that combined treatment with silodosin is useful for overcoming chemoresistance in patients with ELK1-positive urothelial carcinoma receiving cisplatin.

Stiffness of simulated radial neck fractures fixed with 4 different devices

We performed a structural investigation of several fixation devices for radial head and neck fixation. Fourteen pairs of fresh-frozen human elbows were used to simulate unstable radial neck fractures fixed with each of the following plates: 2.0-mm T-plate, 2.0-mm blade plate, 2.7-mm T-plate, and 2.7-mm T-plate modified with a fixed-angle blade. The plate constructs were axially loaded in compression with a materials testing machine, and stiffness was calculated from a load-deformation curve. Through use of paired comparisons, the average stiffness of the modified 2.7-mm plate was found to be significantly greater than that of either 2.0-mm plate, whereas a trend was observed for increased stiffness of the modified 2.7-mm T-plate in comparison with the standard 2.7-mm T-plate. The results indicate that two important variables affecting construct stiffness are plate thickness and incorporation of a fixed-angle blade. Given these findings, the addition of a fixed blade to the 2.7-mm plate may improve the stability of fixation of comminuted radial neck fractures.

An analysis of the suitability of home health visits for telemedicine

To determine what percentage of traditional home health nursing visits could be done by telemedicine, we carried out a retrospective review of nursing charts (clinical records). Data of two types were recorded. The objective data, which were abstracted from the records, included demographic information, patient assessments, teaching activities and interventions. The subjective data were the opinions of four observers as to whether the visit could have been done using currently available telemedicine technology. Records were sampled randomly for patients who had received home nursing care from three home health agencies in rural and urban areas during the winter and summer of 1996. A 54-item coding instrument was applied to 906 different charted home nursing visits. For 412 (46%) of these, the on-site nursing could reasonably have been replaced by telenursing. Significant factors determining the possible use of telenursing included primary diagnosis, number of interventions and patient age. Among the 10 most common primary diagnoses, the most amenable to telenursing care were chronic airway obstruction and joint disorders; the least amenable were coagulation disorders and anaemia. Telenursing visits could substitute for a substantial fraction of on-site home nursing visits. This has important implications in terms of reducing the cost of home nursing care.

Transcending the technology of telemedicine: an analysis of telemedicine in North Carolina

This study investigated the telemedicine program at East Carolina University School of Medicine. In-depth interviews, organizational texts, and archival records provided data for a case study that sought to understand what telemedicine is to organizational members and how they came to create this contextual reality. The goal of this study was to apply interpretive paradigmatic assumptions in the privileging of telemedicine as the very context of the organization. The findings explain how organizational members make sense of this new way of providing health care. Organizational members' talk revealed that telemedicine is multifaceted: It is access, an economic tool, education, technology, and a grant activity. With the single exception of technology, these themes emerged equally, regardless of whether the telemedicine provider was located at the urban hub site or the rural spoke site. Interestingly, members at both locations talked about critical events in relation to receipt of grant or financial support for new projects. Implications for future research are advanced.

Closed cervical spine trauma associated with bilateral vertebral artery injuries

Bilateral vertebral artery injuries in closed cervical spine injuries are uncommon, but early recognition and treatment are important to prevent neurological deterioration. A case of bilateral vertebral injuries in a 35-year-old motor vehicle accident victim is presented, and the current literature is reviewed.

Impact of emergency medicine residents on ancillary test utilization

The effect of the addition of emergency medicine residency on the use of ancillary testing in a teaching hospital's emergency department (ED) staffed previously by emergency medicine board-certified physicians was studied. Prospectively, the utilization of three common ancillary tests (electrolyte levels, X-ray, or electrocardiogram) for four common chief complaints of patients eventually discharged from the ED was evaluated. A 12-month period before and a 15-month period after introduction of an emergency medicine residency program were compared. The mean number of ancillary tests utilized by the ED attending physicians working with residents was compared with the mean number of tests generated by the same physicians (all emergency medicine board-certified) for the same complaints in the year before the residents' arrival. There was no significant difference in test use before and after introduction of the residency (P = .66). Faculty use of tests was also unaffected by the concurrent presence of residents (P = .068). These results show that the use of testing for a sample of common ED complaints was not affected by the introduction of emergency medicine residents to a previously emergency medicine board-certified staff in one community teaching hospital.

Local anesthetics

BACKGROUND

Dermatology is dependent upon the effects of local anesthetics for diagnostic and therapeutic interventions. A working knowledge of the drugs' actions and interactions is necessary for anyone aspiring to optimize the benefits derived from the use of local anesthetic agents.

OBJECTIVE

This article reviews nerve physiology, pharmacology, classification of local anesthetics, adverse reactions (toxic, drug, allergic), local anesthetic use in pregnancy, alternatives to the "-caine" anesthetics, methods for reducing the pain of infiltration, and new agents under development.

CONCLUSION

Local anesthetics are safe and effective. With the understanding of the actions and interactions of this class of drugs, maximum patient safety and satisfaction can be achieved.

Partial Purification of Mucor pusillus Intracellular Proteases

The intracellular protease extracted from the freeze-dried mycelia obtained after the growth of Mucor pusillus at 30°C in corn steep liquor medium was chromatographed on DEAE-A50. Some characteristics of the protease fractions obtained after ion-exchange chromatography were determined and compared with those of the extracellular proteases reported previously. The mycelia were found to contain two acid proteases and an alkaline protease. The ratio of milk clotting to protease activity of one acid protease was greater than that of the other. The electrophoretic pattern of the alkaline protease fraction suggested that it was not a single species, but a mixture of proteolytic enzymes.

Extracellular Proteases of Mucor pusillus

Mucor pusillus was grown in different media for a period of 92 h, and the media were investigated for both milk-clotting and protease activities. It was observed that the ratio of extracellular milk-clotting activity to protease activity was the highest for 3% corn steep liquor containing 1% glucose as the source of carbon. Variation of both milk-clotting and protease activities was studied during the growth of the organism in the medium stated above. Separation of protease was carried out by ion-exchange chromatography at pH 8.0. Fractions collected were assayed for both activities simultaneously. The findings suggested that, instead of only one major acid protease, as reported by previous workers, two major acid proteases were produced. One of them had significant rennin-like activity, and the other lacked it. The former could be assumed to be the enzyme reported and studied by previous workers. The existence of two proteases was further confirmed by the appearance of two protease activity bands on polyacrylamide gels after electrophoresis. An attempt was made to separate the rennin-like enzyme from nonspecific protease activity by ammonium sulfate fractionation followed by ion-exchange chromatography at pH 6.0. The results indicated that the nonspecific protease activity due to the enzyme that lacked rennin action was substantially removed by the ammonium sulfate fractionation.

Study of bound phospholipase activities of fungal mycelia using an organic solvent system

It has been possible to demonstrate and characterize high phospholipase activities in mycelia of Rhizopus arrhizus and Mucor javanicus by use of a system in which substrates were dissolved in diisopropyl ether. Such activities were associated with bound enzymes and would have been difficult to detect using aqueous assay systems. In both cases, phosphatidylcholine hydrolysis was by phospholipase A1 (EC 3.1.1.32) activity followed by the action of lysophospholipase (EC 3.1.1.5). Phospholipase D (EC 3.1.4.4) activity was also detected. The methods used appear to be of general applicability for the detection and study of insoluble phospholipases.