Single-cell genomic variation induced by mutational processes in cancer

How cell-to-cell copy number alterations that underpin genomic instability1 in human cancers drive genomic and phenotypic variation, and consequently the evolution of cancer2, remains understudied. Here, by applying scaled single-cell whole-genome sequencing3 to wild-type, TP53-deficient and TP53-deficient;BRCA1-deficient or TP53-deficient;BRCA2-deficient mammary epithelial cells (13,818 genomes), and to primary triple-negative breast cancer (TNBC) and high-grade serous ovarian cancer (HGSC) cells (22,057 genomes), we identify three distinct 'foreground' mutational patterns that are defined by cell-to-cell structural variation. Cell- and clone-specific high-level amplifications, parallel haplotype-specific copy number alterations and copy number segment length variation (serrate structural variations) had measurable phenotypic and evolutionary consequences. In TNBC and HGSC, clone-specific high-level amplifications in known oncogenes were highly prevalent in tumours bearing fold-back inversions, relative to tumours with homologous recombination deficiency, and were associated with increased clone-to-clone phenotypic variation. Parallel haplotype-specific alterations were also commonly observed, leading to phylogenetic evolutionary diversity and clone-specific mono-allelic expression. Serrate variants were increased in tumours with fold-back inversions and were highly correlated with increased genomic diversity of cellular populations. Together, our findings show that cell-to-cell structural variation contributes to the origins of phenotypic and evolutionary diversity in TNBC and HGSC, and provide insight into the genomic and mutational states of individual cancer cells.

Accurate determination of CRISPR-mediated gene fitness in transplantable tumours

Assessing tumour gene fitness in physiologically-relevant model systems is challenging due to biological features of in vivo tumour regeneration, including extreme variations in single cell lineage progeny. Here we develop a reproducible, quantitative approach to pooled genetic perturbation in patient-derived xenografts (PDXs), by encoding single cell output from transplanted CRISPR-transduced cells in combination with a Bayesian hierarchical model. We apply this to 181 PDX transplants from 21 breast cancer patients. We show that uncertainty in fitness estimates depends critically on the number of transplant cell clones and the variability in clone sizes. We use a pathway-directed allelic series to characterize Notch signaling, and quantify TP53 / MDM2 drug-gene conditional fitness in outlier patients. We show that fitness outlier identification can be mirrored by pharmacological perturbation. Overall, we demonstrate that the gene fitness landscape in breast PDXs is dominated by inter-patient differences.

Evaluation of prognostic risk models for postoperative pulmonary complications in adult patients undergoing major abdominal surgery: a systematic review and international external validation cohort study

BACKGROUND

Stratifying risk of postoperative pulmonary complications after major abdominal surgery allows clinicians to modify risk through targeted interventions and enhanced monitoring. In this study, we aimed to identify and validate prognostic models against a new consensus definition of postoperative pulmonary complications.

METHODS

We did a systematic review and international external validation cohort study. The systematic review was done in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched MEDLINE and Embase on March 1, 2020, for articles published in English that reported on risk prediction models for postoperative pulmonary complications following abdominal surgery. External validation of existing models was done within a prospective international cohort study of adult patients (≥18 years) undergoing major abdominal surgery. Data were collected between Jan 1, 2019, and April 30, 2019, in the UK, Ireland, and Australia. Discriminative ability and prognostic accuracy summary statistics were compared between models for the 30-day postoperative pulmonary complication rate as defined by the Standardised Endpoints in Perioperative Medicine Core Outcome Measures in Perioperative and Anaesthetic Care (StEP-COMPAC). Model performance was compared using the area under the receiver operating characteristic curve (AUROCC).

FINDINGS

In total, we identified 2903 records from our literature search; of which, 2514 (86·6%) unique records were screened, 121 (4·8%) of 2514 full texts were assessed for eligibility, and 29 unique prognostic models were identified. Nine (31·0%) of 29 models had score development reported only, 19 (65·5%) had undergone internal validation, and only four (13·8%) had been externally validated. Data to validate six eligible models were collected in the international external validation cohort study. Data from 11 591 patients were available, with an overall postoperative pulmonary complication rate of 7·8% (n=903). None of the six models showed good discrimination (defined as AUROCC ≥0·70) for identifying postoperative pulmonary complications, with the Assess Respiratory Risk in Surgical Patients in Catalonia score showing the best discrimination (AUROCC 0·700 [95% CI 0·683-0·717]).

INTERPRETATION

In the pre-COVID-19 pandemic data, variability in the risk of pulmonary complications (StEP-COMPAC definition) following major abdominal surgery was poorly described by existing prognostication tools. To improve surgical safety during the COVID-19 pandemic recovery and beyond, novel risk stratification tools are required.

FUNDING

British Journal of Surgery Society.

Clonal fitness inferred from time-series modelling of single-cell cancer genomes

Progress in defining genomic fitness landscapes in cancer, especially those defined by copy number alterations (CNAs), has been impeded by lack of time-series single-cell sampling of polyclonal populations and temporal statistical models1-7. Here we generated 42,000 genomes from multi-year time-series single-cell whole-genome sequencing of breast epithelium and primary triple-negative breast cancer (TNBC) patient-derived xenografts (PDXs), revealing the nature of CNA-defined clonal fitness dynamics induced by TP53 mutation and cisplatin chemotherapy. Using a new Wright-Fisher population genetics model8,9 to infer clonal fitness, we found that TP53 mutation alters the fitness landscape, reproducibly distributing fitness over a larger number of clones associated with distinct CNAs. Furthermore, in TNBC PDX models with mutated TP53, inferred fitness coefficients from CNA-based genotypes accurately forecast experimentally enforced clonal competition dynamics. Drug treatment in three long-term serially passaged TNBC PDXs resulted in cisplatin-resistant clones emerging from low-fitness phylogenetic lineages in the untreated setting. Conversely, high-fitness clones from treatment-naive controls were eradicated, signalling an inversion of the fitness landscape. Finally, upon release of drug, selection pressure dynamics were reversed, indicating a fitness cost of treatment resistance. Together, our findings define clonal fitness linked to both CNA and therapeutic resistance in polyclonal tumours.

Clonal Decomposition and DNA Replication States Defined by Scaled Single-Cell Genome Sequencing

Accurate measurement of clonal genotypes, mutational processes, and replication states from individual tumor-cell genomes will facilitate improved understanding of tumor evolution. We have developed DLP+, a scalable single-cell whole-genome sequencing platform implemented using commodity instruments, image-based object recognition, and open source computational methods. Using DLP+, we have generated a resource of 51,926 single-cell genomes and matched cell images from diverse cell types including cell lines, xenografts, and diagnostic samples with limited material. From this resource we have defined variation in mitotic mis-segregation rates across tissue types and genotypes. Analysis of matched genomic and image measurements revealed correlations between cellular morphology and genome ploidy states. Aggregation of cells sharing copy number profiles allowed for calculation of single-nucleotide resolution clonal genotypes and inference of clonal phylogenies and avoided the limitations of bulk deconvolution. Finally, joint analysis over the above features defined clone-specific chromosomal aneuploidy in polyclonal populations.

Sports interest mediating exercise and compulsive internet use among undergraduates

With the massive growth in Internet technologies, people have become wary of excessive Internet usage, known as compulsive Internet usage or Internet addiction. This study looks into how exercise is related to compulsive Internet usage. Previous research showed varying results regarding the relationship between sports habit and Internet usage; this project clarifies the relationship by investigating mediating variables in terms of interest in different aspects of sports, such as physical education, mastering sport skills, sports participation, and watching sports. Two survey studies were conducted. The participants were 232 male and 107 female Taiwanese undergraduate students in the first survey, totaling 339 students. The second survey had 233 males, 98 female students, and 2 who did not disclose their gender, with a final total of 333. The results reveal that interest in physical education (IPE) mediates sports habit and compulsive Internet usage. As long as the student had a habit of doing sports that increased IPE, this would in turn decrease compulsive Internet use. The importance of igniting students' IPE is discussed.

Outcomes following debridement, antibiotics and implant retention in the management of periprosthetic infections of the hip: a review of cohort studies

AIMS

The aims of the study were to review and analyse the reported series of debridement, antibiotics and implant retention (DAIR) in the management of infected total hip arthroplasties (THAs) to establish the overall success and the influencing factors.

PATIENTS AND METHODS

Using a standardised recognised study protocol, meta-analysis of observational studies in epidemiology guidelines, a comprehensive review and analysis of the literature was performed. The primary outcome measure was the success of treatment. The search strategy and inclusion criteria which involved an assessment of quality yielded 39 articles for analysis, which included 1296 patients.

RESULTS

The proportion of success following DAIR in the management of an infected THA appeared to improve after 2004 with a pooled mean proportion of success of 72.2%. For all reported series, from 1977 onwards, there was improved success with early debridement (< 7 days; 75.7%) and exchange of modular components (77.5%). There was a statistically non-significant improvement if debridement was performed within four weeks of the initial procedure (73.0%).

CONCLUSION

The reported success following DAIR has improved since 2004. The only determinants of outcome which we found were the timing of debridement after the onset of symptoms of infection and the exchange of modular components. Cite this article: Bone Joint J 2017;99-B:1488-66.

Neurodevelopmental Outcomes Following Extensive Cardiopulmonary Resuscitation in the Delivery Room for Infants Born &lt;29 Weeks’ Gestational Age

BACKGROUND: Neurodevelopmental outcomes of preterm infants who receive extensive CPR (ECPR), defined as chest compression with or without epinephrine in the delivery room, remain unclear.

OBJECTIVES: To compare the neurodevelopmental outcomes of preterm infants admitted to Canadian NICUs requiring ECPR versus those who did not require ECPR in the delivery room.

DESIGN/METHODS: Preterm infants born at &lt;29 weeks GA between January 1, 2010 and September 30, 2011 and evaluated at CNFUN centers were retrospectively evaluated. The primary outcome was a composite of death or neurodevelopmental impairment (NDI) at 18-21 months CA defined as presence of any one or more of the following: definitive cerebral palsy or Bayley- III cognitive, language, motor scores &lt;85 on any one of the components or hearing impairment or visual impairment. Demographic factors, neurodevelopmental status including Bayley III cognitive, language and motor scores and sensory impairments were compared between the ECPR and the no ECPR group using univariate and multivariate analyses. RESULTS: Of 2488 eligible infants, 197 (7.9%) received ECPR. 83% of surviving infants had follow-up data. Demographic and outcomes data are summarized below in Table 1 and 2 respectively.

Multiple human papillomavirus infections and HIV seropositivity as risk factors for abnormal cervical cytology among female sex workers in Nairobi

We estimated type-specific prevalence of human papillomavirus (HPV) and examined risk factors for abnormal cervical cytology among 296 female sex workers from Nairobi, Kenya. Over half (54%) were infected with a high-risk (HR) HPV type, of which HPV16 and 52 were the most common types. HIV-1 prevalence was 23% and HIV-1 sero-positivity was associated with high-grade cervical lesions, particularly among women with CD4 count less than 500 cells/mm(3) (odds ratio [OR] = 6.9; 95% confidence interval [CI]: 1.7-24.9). Among women who had normal cytology at the time of entry into the study, the risk of having an abnormal Pap smear within one year was significantly elevated for women with multiple HPV types at study entry (adjusted odds ratio [aOR] = 6.0; 95% CI: 2.3-15.7) and with a subset of HR HPV types (aOR = 4.2; 95% CI: 1.6-11.2). Detection of multiple concurrent HPV infections may be a useful marker to identify women at risk of developing precancerous lesions in populations of high HPV prevalence.

MO-A-BRB-02: Facts and Fiction of Flattening Filter Free (FF-FFF) X-Rays Beams

The primary purpose of the FFF X-rays is to provide much higher dose rates available for treatments. For example, FFF X-rays from Varian TrueBEAM can deliver 1400 MU/minute for 6 MV X-rays and 2400 MU/minutes for 10 MV X-rays. Higher dose rates have definite clinical benefits in organ motion management. For example, larger dose fractions can be delivered in a single breath-hold or gated portion of a breathing cycle. In SRS or SBRT treatments, large MUs are often required and FFF X-ray beams can deliver these large MUs in much shorter "beam-on" time. With shorten treatment time, these FFF X-rays improve patient comfort and dose delivery accuracy. FFF X-ray beams may become one of the necessary equipment configurations for SBRT and/or SRS treatments, in the future. This presentation will address some unique issues dealing with the FFF X-rays: (1) FIELD SIZES flattening Filter Free (FFF) X-ray beam has been in clinical use for quite some time. However, not until recently, these FFF beams are used in limited, small field sizes, for example, in Tomotherapy and CyberKnife machines.Varian TrueBEAM allows the FFF X-ray beam to have up to 40 × 40 cm field sizes for both 6 and 10 MV X-rays (15 MV FFF X-rays are not yet released for clinical use). For large treatment fields, the dose uniformity within an irradiated treatment field will need to be "modulated" by MLC movements (IMRT) to cut down the higher beam intensity near the central portion of the FFF X-ray beam. Thus, larger MUs are required compared with a conventional (flattened) X-ray beam. Or, MLC movements (EVIRT) are now being used to "flatten" the FFF X-rays to provide dose uniformity within those large PTVs. The high dose rates from the FFF X-rays are now being off-set by the larger MUs requirements. Therefore, FFF X-rays can bring clinical advantages over conventional X-rays when used with small field sizes, such as in SBRT and/or SRS applications. (2) DOSEVIETRY MEASUREMENT EQUIMENT: Because of the more than 2 to 4 fold increases in dose rate (MU/minute), the radiation measurement equipment and techniques need to be carefully evaluated, such as ionization chamber characteristics, electrometers, scanning equipment. First comes to mind is the ion-recombination characteristics of the ionization chamber (P-ion). This will determine the accuracies of the measured percentage depth doses and penumbra of these FFF X-ray fields. And, it will also affect the absolute dose measurements (Gy/MU) using the TG-51 formulations. The measured PDDs and profiles should be corrected for the P-ion effect. However, it is not a simple task for physicists to perform the P-ion corrections for PDDs and profiles using the presently available methods associated in commercial 3-D scanning equipment and algorithm. It may become necessary for physicists to adapt and get accustom to the use of "standard beam data" provided by manufacturers in the future. In addition, because of the use of FFF X-rays are focused on SBRT and/or SRS applications, beam data acquisition, scanning techniques, and beam modeling are vitally important. There are many publications addressing the "output factors" from small fields, but none pay enough attention to the penumbra characteristics of these small X-ray beams. Because of the proximity to critical organs, the penumbra characteristics of small fields are often more clinically important than output factors. FFF X-rays play an important role in SBRT and SRS applications. Therefore, careful penumbra measurements should be addressed. Again, it may become necessary for physicists to adapt the use of "standard beam data" provided by manufacturers. (3) RADIO-BIOLOGICAL QUESTION: Though there is a lack of controlled clinical studies with FFF X-ray beams, there are several scientific articles addressing the radiobiological concerns of high dose rate deliveries, especially when it is used to deliver large doses per fraction, such as 10 Gy/faction. This type of dose per fraction is often used in SBRT or SRS treatments. Radiobiological concerns are not in the cell kill effect within the target volume. It is the normal tissue damages surrounding the target. There are concerns about the late toxicities of these high dose rate and high dose per fraction deliveries using FFF X-ray beams. (4) SKIN (ENTRANCE) DOSE DISCUSSIONS: In conventional X-ray beams, the low energy components of the X-ray beam are removed by the in-line X-ray flattening filter. But, in Flatten Filter Free X-ray beams, these low energy components are exiting the X-ray collimators. This is clearly documented by the difference in the percentage depth doses for these FFF X-ray beams. The FFF X-ray beams have a lower "effective energy" compared to conventional X-rays. Therefore, it is important to study the skin (entrance) dose from these FFF X-rays. In the literature, reported skin (entrance) doses from different linear accelerator manufacturers vary widely. Skin doses from Varian TrueBEAM have been studied and have found to be marginally higher than the conventional X-rays. However this margin increase is not clinically significant.(5) Summary / conclusions / discussions: The FFF X-rays improve the treatment delivery by their very high dose rates (1400 and 2400 MU/minute) and shortened treatment time. FFF X-ray beams are most applicable and the high dose rates are most advantageous when the treatment field sizes are small. The dosimetry of FFF-X-rays is made more complex by the P-ion determination and necessary corrections to X-ray beam percentage depth doses and profiles. There are radiobiological concerns about late toxicity of normal tissue irradiated by FFF X-rays when large dose per faction treatment applications are used. There are wide ranges of skin doses from these FFF X-rays reported in the literature.

LEARNING OBJECTIVES

1. Flattening Filter Free X-rays have been in clinical use for many years but mostly for small field sizes. 2. Flattening Filter Free X-rays have significantly shorter treatment time if is used for small field applications, such as: SBRT or SRS. 3. Because of the high dose rate (MU/minute), dosimetric properties of these FFF X-rays need to be carefully studied. Ion-recombination of ionization chambers is a concern. Beam data acquisition, beam modeling, and absolute dosimetry need to be done with great care, especially in small field applications. 4. Late toxicities of normal tissue may be a concern and need to be studied by organized clinical protocols.

Evaluation of the prevalence of trachoma 12 years after baseline surveys in Kidal Region, Mali

OBJECTIVE

After prevalence surveys in all eight regions, Mali started a national programme to control trachoma in 1998. In the sparsely populated desert region of Kidal, where active trachoma prevalence was 46.2% in children under 10, no interventions beyond routine eye-care services were implemented. We estimated the prevalence of trachoma in Kidal, 12 years after baseline mapping surveys, to determine whether interventions to control trachoma were warranted.

METHODS

A total of 2165 individuals from 477 households were examined for clinical trachoma signs in a cluster survey using the WHO simplified grading system. Individual and household risk factors for trachoma were assessed.

RESULTS

The prevalence of follicular trachomatous inflammation (TF) in children 1-9 years of age was 15.6% (95% CI 11.8-19.5%). Trachomatous trichiasis (TT) was observed in 4 persons for an overall prevalence in all ages of 0.16% (95% CI 0.0-0.35%). Estimated household latrine coverage in the region was 33.1% (95% CI 14.0-52.2%). Residents of 52.8% of surveyed households reported access to a water source outside geographical boundaries of their communities.

CONCLUSIONS

In the absence of control interventions, the prevalence of clinical signs of trachoma among children was substantially lower than estimates 12 years earlier. The current prevalence of active trachoma remains above the threshold adopted by WHO, yet there is little evidence of chronic blinding trachoma.

Wound Fluid Induces Cancer Cell Growth: A Mechanism for Recurrence?

Background: The process of wound healing after surgical resection of breast cancer may contribute to the development of local recurrence and possibly even metastases. Local recurrence after lumpectomy or mastectomy occurs most frequently near the surgical scar, leading to the hypothesis that the wound itself may promote the growth of residual disease. Some studies even suggest that removal of the primary tumor can accelerate progression of occult metastases. Two studies have shown that wound fluid can stimulate the growth of cancer cells and that differing cancer cell lines may be stimulated by differing wound fluid. A major criticism of these studies is that the activity of the wound fluid was compared to either the patient serum, which is likely less inflammatory than the wound fluid, or to serum free media. Thus, these studies did not define whether the inflammatory component of wound fluid alone is sufficient to stimulate cancer cell growth or whether the ability was specific to breast derived wound fluid. In this pilot study wound fluid was collected from 10 patients who had undergone unilateral mastectomy with abdominal flap reconstruction or bilateral mastectomy where one breast had known cancer and the contralateral did not. In the unilateral mastectomy patients, the fluid from the involved breast was compared to the fluid from the abdominal drain. In the bilateral mastectomy patients the fluid from the breast with cancer was compared with the fluid from the prophylactically removed breast. The effect of wound fluid on the growth of breast cancer cells was analyzed for each patient.Methods: Fluid from each breast and abdominal drain were collected 24 and 48 hours after surgery and their ability to promote growth of 6 different breast cancer cell lines was tested. In addition, the ability of the 48 hour wound fluid to stimulate colony formation of HBL-100 cells (ER-) on matrigel was established. The cytokine profile of the different wound fluid was also analyzed.Results: We found that when the ER – cells were cultured on matrigel, the breast derived fluid led to growth of invasive, branching colonies, while abdominal fluid from the same patient led to small round colonies. Further, we found that wound fluid derived from the breast where a tumor was present led to the formation of more invasive colonies than the wound fluid derived from the normal breast. Thus, we speculate that in addition to the normal cytokines and matrix metalloproteases associated with inflammation, breast wound fluid may contain additional proteins from the tumor bed microenvironment. In support of this model, we found that the protein composition of wound fluid varies from one site to another in the same patient.Conclusion: The biological activity and protein composition of wound fluid from the breast and abdomen is drastically different—such that breast wound fluid promotes growth and invasion of breast cancer cells. Thus, we hypothesize that residual disease may be stimulated to grow during the window of time after surgery when the wound fluid is produced. This transient stimulation may result in local recurrence if the nature of the residual disease is a foci cancer or acceleration of metastasis if the residual disease is disseminated into the surrounding lymph nodes or blood vessels.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 3146.

Transcriptional coactivator, CIITA, is an acetyltransferase that bypasses a promoter requirement for TAF(II)250

The CIITA coactivator is essential for transcriptional activation of MHC class II genes and mediates enhanced MHC class I transcription. We now report that CIITA contains an intrinsic acetyltransferase (AT) activity that maps to a region within the N-terminal segment of CIITA, between amino acids 94 and 132. The AT activity is regulated by the C-terminal GTP-binding domain and is stimulated by GTP. CIITA-mediated transactivation depends on the AT activity. Further, we report that, although constitutive MHC class I transcription depends on TAF(II)250, CIITA activates the promoter in the absence of functional TAF(II)250.

Gamma knife radiosurgery for large volume brain tumors: an analysis of acute and chronic toxicity

Gamma Knife radiosurgery is often used to treat intracranial tumors <4 cm (approximately 13.5 cm3) in mean diameter. Larger lesions are rarely treated because of the expectation that increasing target volume will increase toxicity. We retrospectively analyzed 35 patients with primary or metastatic brain tumors of more than 13.5 cm3 treated with the Gamma Knife. Only 3 (8.5%) patients developed acute clinical toxicity. Nine (25%) patients developed post-Gamma Knife radionecrosis based on imaging studies, with only 3 of these patients (9% of the study population) having clinical progression of symptoms. Necrosis was not found to be related to prescribed dose, treatment volume or number of treated isocenters. We found no undue toxicity from the treatment of large brain tumors with the Gamma Knife.

Dose volume histogram analysis of the gamma knife radiosurgery treating twenty-five metastatic intracranial tumors

Treating multiple brain metastatic sites in Gamma Knife radiosurgery is not uncommon. Most metastases can be treated with few or even one single shot. Occasionally we have patients returning for retreatment for different intracranial metastatic sites at different times. Dose distribution for these metastases are prescribed locally without considering the previous dose contribution. We present a study which simultaneously calculates the dose distribution of 25 randomly placed shots distributed inside the intracranial region. The Dose Volume Histogram (DVH) is plotted to study the coverage of the tumor sites and normal tissues. We have calculated ten DVH studies and show that 50% of the brain volume receives less than 500 cGy for the maximum tumor dose of 40 Gy, and the dose gradient is extremely steep. This DVH analysis shows that the Gamma Knife radiosurgery is a good treatment modality to control the local tumors while maintaining normal brain function, even for the large number of brain metastasis treated at different times.

DNA elements recognizing NF-Y and Sp1 regulate the human multidrug-resistance gene promoter

Regulation of the human multidrug resistance gene (hMDR1) was studied by mapping DNA elements in the proximal promoter necessary for efficient transcription. Transient transfection analysis in tumor cell lines (HCT116, HepG2, and Saos2) of promoter deletions identified several regulatory domains. These cell lines expressed hMDR1 mRNA. Removal of an element between +25 and +158 reduced promoter activity by 2-3-fold, whereas deletion of sequences from approximately -5000 to -138 base pairs gave a approximately 2-fold increase. The activity of the hMDR1 promoter (-137 to +25) was comparable in activity to the SV40 early promoter and enhancer combination. Deletion of the hMDR1 promoter between -86 and -44 reduced activity by 5-10-fold, identifying an important regulatory region. This minimal region (-88 to -37) activated transcription when inserted upstream of a synthetic promoter, suggesting that it acts independently of other regulatory sequences. Two DNA elements within 85 base pairs of the transcriptional start site were required to confer efficient gene expression. A double-point mutation in the Y box (inverted CCAAT box) between -70 and -80 reduced activity of the promoter by 5-10-fold, and a single-point mutation at -52 within a GC-rich element reduced activity by 3-fold. Thus, both the Y-box and GC elements must each remain intact for optimal promoter activity. DNA-binding analyses suggest that the transcription factor NF-Y, but not YB-1 or c/EBP, is most likely responsible for controlling the activity of the Y-box element in these tumor cell lines. DNA-binding analyses also suggest that Sp1, alone or in combination with other nuclear factors, likely controls the activity of the GC element.

Carbon dioxide laser transconjunctival lower lid blepharoplasty complications

Lower eye lid blepharoplasty is a frequent cosmetic procedure. The carbon dioxide laser transconjunctival approach is a popular alternative to conventional techniques. Eight hundred eighty-nine consecutive cases were studied retrospectively to determine the occurrence of complications. All cases were included. Complications were divided into intraoperative, immediate postoperative (days 1-7) and late postoperative (greater than 7 days). Complications encountered in this study of carbon dioxide laser conjunctival blepharoplasty were uncommon and not severe.

Characterization and cloning of a receptor for BMP-2 and BMP-4 from NIH 3T3 cells

The bone morphogenetic proteins (BMPs) are a group of transforming growth factor beta (TGF-beta)-related factors whose only receptor identified to date is the product of the daf-4 gene from Caenorhabditis elegans. Mouse embryonic NIH 3T3 fibroblasts display high-affinity 125I-BMP-4 binding sites. Binding assays are not possible with the isoform 125I-BMP-2 unless the positively charged N-terminal sequence is removed to create a modified BMP-2, 125I-DR-BMP-2. Cross-competition experiments reveal that BMP-2 and BMP-4 interact with the same binding sites. Affinity cross-linking assays show that both BMPs interact with cell surface proteins corresponding in size to the type I (57- to 62-kDa) and type II (75- to 82-kDa) receptor components for TGF-beta and activin. Using a PCR approach, we have cloned a cDNA from NIH 3T3 cells which encodes a novel member of the transmembrane serine/threonine kinase family most closely resembling the cloned type I receptors for TGF-beta and activin. Transient expression of this receptor in COS-7 cells leads to an increase in specific 125I-BMP-4 binding and the appearance of a major affinity-labeled product of approximately 64 kDa that can be labeled by either tracer. This receptor has been named BRK-1 in recognition of its ability to bind BMP-2 and BMP-4 and its receptor kinase structure. Although BRK-1 does not require cotransfection of a type II receptor in order to bind ligand in COS cells, complex formation between BRK-1 and the BMP type II receptor DAF-4 can be demonstrated when the two receptors are coexpressed, affinity labeled, and immunoprecipitated with antibodies to either receptor subunit. We conclude that BRK-1 is a putative BMP type I receptor capable of interacting with a known type II receptor for BMPs.

A simple method of producing depth ionization data for electron energy constancy check

A simple method has been developed to reproduce depth ionization data of electron beams for energy determination. The method utilizes a simple set of equipment, a combination of a specially designed wedge-shaped polystyrene phantom and a linear array of detectors, to collect the necessary data. The wedge-shaped phantom provides varying depths to various detectors in the array. The ionization readings received from the detectors were corrected for off-axis ratio and plotted against corresponding ray-line depths to produce depth ionization curves. The instrument setup was fast and simple. The relevant data, for a high-energy linear accelerator with multiple electron energies, were collected in minutes. The depths of 80% and 50% ionization determined by this method were found to differ by 2 and 3 mm, respectively, at the most, with those determined by a conventional method.

Radiation therapy as a treatment for benign lymphoepithelial parotid cysts in patients infected with human immunodeficiency virus-1

Patients who are infected with the human immunodeficiency virus (HIV) may develop benign lymphoepithelial cysts within the parotid gland that cause severe facial deformity. Standard treatment for this disorder has been superficial parotidectomy, repeated fine-needle aspirations or observation alone. These approaches are unsatisfactory because elective surgery in immunocompromised patients should be avoided, the cysts recur soon after aspiration, and observation alone for a treatable deforming facial process is unacceptable. Radiotherapy's proven effectiveness in treating other benign disorders of the parotid gland led us to evaluate its usefulness as a treatment for this disorder. Eight patients with parotid enlargement, who were seropositive for HIV, received 8-10 Gy to the parotids in 1 week. Five patients had complete response and three patients had partial response. All were very satisfied with the cosmetic result. Treatment-related toxicity was well tolerated and consisted of mild xerostomia and transient taste loss. In all cases, these side effects resolved within 1 month. Radiation therapy thus appears to be an effective and well-tolerated treatment for AIDS-related parotid enlargement.

Inhibition of autoproteolytic activation of interstitial procollagenase by recombinant metalloproteinase inhibitor MI/TIMP-2

The purification and cloning of a novel metalloproteinase inhibitor (MI or TIMP-2) related to tissue inhibitor of metalloproteinases (TIMP) has been recently described by our laboratory (DeClerck, Y.A., Yean, T. D., Ratzkin, B.J., Lu, H.S., and Langley, K.E. (1989) J. Biol. Chem. 264, 17445-17453; Boone, T.C., Johnson, M.J., DeClerck, Y.A., and Langley, K.E. (1990) Proc. Natl. Acad. Sci. U. S. A. 87, 2800-2804). We have transfected Chinese hamster ovary cells with a vector containing human MI/TIMP-2 cDNA and purified recombinant-derived MI/TIMP-2 (rMI/rTIMP-2) from the conditioned medium of such cells. We have investigated the inhibitory activity of rMI/rTIMP-2 toward rabbit fibroblast interstitial collagenase. The inhibition of activated collagenase by rMI/rTIMP-2 is stoichiometric and consistent with the formation of a 1:1 molar ratio complex. In addition to blocking the activated enzyme, rMI/rTIMP-2 inhibits the conversion of 52-kDa procollagenase to the 42-kDa active enzyme initiated by organomercurials. When plasmin is used as activator, rMI/rTIMP-2 does not inhibit the plasmin-mediated conversion of the 52-kDa proenzyme to the 46-kDa inactive intermediate but blocks further conversion of the 46-kDa intermediate to the 42-kDa active enzyme. The data indicate that rMI/rTIMP-2 blocks the autoproteolytic activation of procollagenase. Also, rMI/rTIMP-2 forms complexes with the 52-kDa procollagenase, the 46-kDa intermediate, and with the 42-kDa activated enzyme which are stable to sodium dodecyl sulfate (SDS), such that the complexes can be visualized by SDS-polyacrylamide gel electrophoresis. It appears that the formation of a SDS-stable complex with procollagenase requires an initial conformational change of the procollagenase brought about by organomercurials or by plasmin cleavage. The data suggest that MI/TIMP-2 may be able to control the extracellular action of certain metalloproteinases not only at the level of the activated enzyme but also at the level of proenzyme activation.

Technique of venous catheterization for sequential blood sampling from the pig

A surgical technique for catheter implantation for sequential blood sampling in the pig is described. This methodology minimizes stress to the animal and chances of catheter dislodgement, both of which are detrimental to accurate long-term metabolic assessment of the animal model. The technique involves implantation of a vinyl catheter via the external jugular vein into the vena cava. To ensure catheter retention, the method uses a silicone plug fitted to the catheter and located cranial to its entry to the vein, double ligation at the venous insertion, subsequent passage of the catheter to exit 10 cm cranial to the scapula on the dorsal midline, and a denim vest fitted to the thorax. With this technique seven out of nine catheters have functioned more than 50 days, two functioned for approximately 100 days, and one for over 150 days.

Analysis of workload and staffing requirements for a critical-care satellite pharmacy

A study to determine the workload and the staffing requirements of a proposed critical-care satellite pharmacy is reported. Data for all patients admitted to the adult surgical intensive-care units (SICUs) of an acute-care teaching hospital were recorded for 30 days. Both clinical and distributive data were collected, such as the number and times of patient admissions to the SICUs, the times medication orders were written and their nature, the number and types of drugs administered per patient per day, the number of medication profile reviews per day, and the number and types of interventions. Productivity standards were determined for specific clinical and distributive tasks and used to project the staffing requirements of the new satellite pharmacy. It was determined that proposed changes in distributive services, including expansion of the i.v. admixture program and implementation of a syringe-pump infusion system, would increase the pharmacist and technician staffing requirements by 1.91 and 6.77 hours per day, respectively. Expansion of clinical services, such as pharmacokinetic monitoring, would increase the pharmacist staffing requirements by 8.68 hours per day. It was estimated that the SICU satellite pharmacy could save the hospital more than $200,000 per year. Hospital administration approved a request to increase staffing by 3 full-time-equivalent (FTE) pharmacists and 1.6 FTE technicians. Workload analyses and projections of staffing requirements must incorporate measurements for clinical as well as distributive services.

Primary structure and functional expression of rat and human stem cell factor DNAs

Partial cDNA and genomic clones of rat stem cell factor (SCF) have been isolated. Using probes based on the rat sequence, partial and full-length cDNA and genomic clones of human SCF have been isolated. Based on the primary structure of the 164 amino acid protein purified from BRL-3A cells, truncated forms of the rat and human proteins have been expressed in E. coli and mammalian cells and have been shown to possess biological activity. SCF is able to augment the proliferation of both myeloid and lymphoid hematopoietic progenitors in bone marrow cultures. SCF exhibits potent synergistic activities in conjunction with colony-stimulating factors, resulting in increased colony numbers and colony size.

Computerized ambulatory-care pharmacy information system for direct order entry by prescribers

A computer system that links prescribers in a diabetes center to an ambulatory-care satellite pharmacy is described. In 1988 an ambulatory-care center serving the diabetic patients of a 437-bed university teaching hospital moved to a new location. To maintain efficient communication of prescription information from the diabetes center to a designated ambulatory-care satellite pharmacy, a program that enables diabetes center prescribers to enter their orders directly into the satellite pharmacy computer system was implemented. The pharmacy department's prescription-entry screen was reprogrammed so that it could be more easily used by prescribers, and a "default" list of the most frequently prescribed drugs was generated to simplify direct order entry. Prescription information entered at the diabetes center is transmitted to the satellite pharmacy; the filled prescriptions are usually ready by the time patients arrive. The average number of prescriptions entered into the computer per week remained steady during the first 14 weeks that the system was in use but increased substantially after diabetes center personnel were given a summary of use data and other information pertaining to the new system. However, because of the availability of only one terminal for order entry and the inherent ease and speed of writing prescriptions on paper, use of the system has not met expectations despite the benefits it offers. Prescribers in a diabetes center did not frequently enter prescription information into a computer system linked to the hospital's ambulatory-care pharmacy because the traditional method of writing prescriptions remained available and convenient.

Identity of the immunoglobulin heavy-chain-binding protein with the 78,000-dalton glucose-regulated protein and the role of posttranslational modifications in its binding function

The 78,000-dalton glucose-regulated protein (GRP78) and the immunoglobulin heavy-chain-binding protein (BiP) were shown to be the same protein by NH2-terminal sequence comparison. Immunoprecipitation of GRP78-BiP induced by glucose starvation and a temperature-sensitive mutation in a hamster fibroblast cell line demonstrated the association of GRP78-BiP with other cellular proteins. In both fibroblasts and lymphoid cells, GRP78-BiP was found to label with 32Pi and [3H]adenosine. Phosphoamino acid analysis demonstrated that GRP78-BiP is phosphorylated on serine and threonine residues. Conditions which induce increased production of GRP78-BiP resulted in decreased incorporation of 32Pi and [3H]adenosine into GRP78-BiP. Furthermore, we report here that the phosphorylated form of BiP resides in the endoplasmic reticulum and that BiP which is associated with heavy chains is not phosphorylated or labeled with [3H]adenosine, whereas free BiP is. This suggests that posttranslational modifications may be important in regulating the synthesis and binding of BiP.

Human gene encoding the 78,000-dalton glucose-regulated protein and its pseudogene: structure, conservation, and regulation

The isolation and characterization of a human functional GRP78 gene and a processed pseudogene are described. We present the complete primary structure of the human GRP78 gene, which spans over 5 kb and consists of eight exons. Sequence comparisons reveal that the GRP78 gene shares unusual homology among the human, rat, and hamster in the protein-coding and 3' untranslated regions. In addition, short domains highly conserved with HSP70 isolated from human, Drosophila, Xenopus, yeast, and E. coli DNA are identified within the hydrophobic regions of GRP78. The intronless pseudogene resembles that of a processed gene. It is flanked by a short direct repeat and is embedded within an AT-rich genomic region. The highly active promoter from the functional human GRP78 gene contains a TATA box, five CCAAT sequences, and two potential binding sites for the transcriptional factor Sp1. It consists of a distal domain that enhances basal level expression and a proximal domain essential for responses to calcium ionophore and for a temperature-sensitive mutation which induce the GRP78 gene. Both domains are highly conserved between the rat and the human GRP78 promoters.

Interleukin 2 responses of lpr and normal L3T4-/Lyt-2- T cells induced by TPA plus A23187

The major population of cells that accumulate abnormally in MRL/Mp-lpr/lpr lymphoid tissue is Thy-1+, L3T4-, and Lyt-2-. To clarify the functional potential of these cells, we examined their proliferation, interleukin 2 (IL 2) receptor expression, and IL 2 secretion by using as stimulants the combination of 12-O-tetradecanoylphorbol-2-acetate and A23187 (a calcium ionophore). Although the lpr T cells were capable of responding to these stimulants, the nature of the response and of the concentrations of ligand required differed sharply from the responses of normal adult T cells, and of adult L3T4-Lyt-2- thymocytes. There was a strong similarity but not identity when responses of 16 day fetal thymocytes were compared with those of lpr L3T4-Lyt-2- cells. The unusual functional properties of the lpr cells, such as high A23187 dose requirement for maximal proliferation, low percentage of IL 2 receptor-expressing cells, and low levels of IL 2 secretion, suggested that these cells are arrested at a stage of development similar to that of 16-day fetal thymocytes and before adult L3T4-/Lyt-2- thymocytes.