Prevalence of Frailty in European Emergency Departments (FEED): an international flash mob study

INTRODUCTION

Current emergency care systems are not optimized to respond to multiple and complex problems associated with frailty. Services may require reconfiguration to effectively deliver comprehensive frailty care, yet its prevalence and variation are poorly understood. This study primarily determined the prevalence of frailty among older people attending emergency care.

METHODS

This cross-sectional study used a flash mob approach to collect observational European emergency care data over a 24-h period (04 July 2023). Sites were identified through the European Task Force for Geriatric Emergency Medicine collaboration and social media. Data were collected for all individuals aged 65 + who attended emergency care, and for all adults aged 18 + at a subset of sites. Variables included demographics, Clinical Frailty Scale (CFS), vital signs, and disposition. European and national frailty prevalence was determined with proportions with each CFS level and with dichotomized CFS 5 + (mild or more severe frailty).

RESULTS

Sixty-two sites in fourteen European countries recruited five thousand seven hundred eighty-five individuals. 40% of 3479 older people had at least mild frailty, with countries ranging from 26 to 51%. They had median age 77 (IQR, 13) years and 53% were female. Across 22 sites observing all adult attenders, older people living with frailty comprised 14%.

CONCLUSION

40% of older people using European emergency care had CFS 5 + . Frailty prevalence varied widely among European care systems. These differences likely reflected entrance selection and provide windows of opportunity for system configuration and workforce planning.

Impact of supplementary air filtration on aerosols and particulate matter in a UK hospital ward: a case study

BACKGROUND

Aerosol spread of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is a major problem in hospitals, leading to an increase in supplementary high-efficiency particulate air filtration aimed at reducing nosocomial transmission. This article reports a natural experiment that occurred when an air cleaning unit (ACU) on a medicine for older people ward was switched off accidentally while being commissioned.

AIM

To assess aerosol transport within the ward and determine whether the ACU reduced airborne particulate matter (PM) levels.

METHODS

An ACU was placed in a ward comprising two six-bedded bays plus three single-bed isolation rooms which had previously experienced several outbreaks of coronavirus disease 2019. During commissioning, real-time measurements of key indoor air quality parameters (PM1-10, CO2, temperature and humidity) were collected from multiple sensors over 2 days. During this period, the ACU was switched off accidentally for approximately 7 h, allowing the impact of the intervention on PM to be assessed.

FINDINGS

The ACU reduced the PM counts considerably (e.g. PM1 65.5-78.2%) throughout the ward (P<0.001 all sizes), with positive correlation found for all PM fractions and CO2 (r=0.343-0.817; all P<0.001). PM counts rose/fell simultaneously when the ACU was off, with correlation of PM signals from multiple locations (e.g. r=0.343-0.868; all P<0.001) for particulates <1 μm).

CONCLUSION

Aerosols migrated rapidly between the various ward subcompartments, suggesting that social distancing alone cannot prevent nosocomial transmission of SARS-CoV-2 as this fails to mitigate longer-range (>2 m) transmission. The ACU reduced PM levels considerably throughout the ward space, indicating its potential as an effective intervention to reduce the risk posed by infectious airborne particles.

Suboptimal sleep and incident cardiovascular disease among African Americans in the Jackson Heart Study (JHS)

BACKGROUND

Suboptimal sleep, including insufficient/long sleep duration and poor sleep quality, is a risk factor for cardiovascular disease (CVD) common but there is little information among African Americans, a group with a disproportionate CVD burden. The current study examined the association between suboptimal sleep and incident CVD among African Americans.

METHODS

This study included 4,522 African Americans without CVD at baseline (2000-2004) of the Jackson Heart Study (JHS). Self-reported sleep duration was defined as very short (<6 h/night), short (6 h/night), recommended (7-8 h/night), and long (≥9 h/night). Participants' self-reported sleep quality was defined as "high" and "low" quality. Suboptimal sleep was defined by low quality sleep and/or insufficient/long sleep duration. Incident CVD was a composite of incident coronary heart disease and stroke. Associations between suboptimal sleep and incident CVD were examined using Cox proportional hazards models over 15 follow-up years with adjustment for predictors of CVD risk and obstructive sleep apnea.

RESULTS

Sample mean age was 54 years (SD = 13), 64% female and 66% reported suboptimal sleep. Suboptimal sleep was not associated with incident CVD after covariate adjustment [HR(95% CI) = 1.18(0.97-1.46)]. Long [HR(95%CI) = 1.32(1.02-1.70)] and very short [HR(95% CI) = 1.56(1.06-2.30)] sleep duration were associated with incident CVD relative to recommended sleep duration. Low quality sleep was not associated with incident CVD (p = 0.413).

CONCLUSIONS

Long and very short self-reported sleep duration but not self-reported sleep quality were associated with increased hazard of incident CVD.

Parasitic dinoflagellate Hematodinium perezi prevalence in larval and juvenile blue crabs Callinectes sapidus from coastal bays of Virginia

The parasitic dinoflagellate Hematodinium perezi infects the American blue crab Callinectes sapidus and other decapods along the Eastern seaboard and Gulf of Mexico coast of the USA. Large juvenile and adult blue crabs experience high mortality during seasonal outbreaks of H. perezi, but less is known about its presence in the early life history stages of this host. We determined the prevalence of H. perezi in megalopae and early benthic juvenile crabs from multiple locations along the Virginia portion of the Delmarva Peninsula. The DNA of H. perezi was not detected in any megalopae collected from several locations within the oceanic coastal bay complex in which H. perezi is found at high prevalence levels. However, prevalence levels were high in early benthic juveniles from 2 oceanic coastal embayments: South Bay and Cobb Bay. Prevalence levels were lower at locations within Chesapeake Bay, including Cherrystone Creek, Hungars Creek, and Pungoteague Creek. Sampling over different seasons and several consecutive years indicates that disease transmission occurs rapidly after megalopae settle in high-salinity bays along the Delmarva Peninsula during the late summer and fall. Infected juvenile crabs can overwinter with the parasite and, when subjected to increasing water temperatures in spring, infections progress rapidly, culminating in transmission to other crabs in late spring and early summer. In high-salinity embayments, H. perezi can reach high prevalence levels and may significantly affect recruitment of juvenile blue crabs into the adult fishery.

Temozolomide as a Single Agent Maintenance Therapy in Elderly Patients With Primary CNS Lymphoma

INTRODUCTION

Optimal management of elderly patients with primary central nervous system lymphoma (PCNSL) after induction therapy is unclear. Whole-brain radiotherapy and autologous stem cell transplantation carry increased toxicity in patients older than 60 years of age, which might outweigh the benefits in this group. Temozolomide (TMZ) has established antineoplastic activity in the central nervous system in other disease states, with a favorable toxicity profile.

PATIENTS AND METHODS

We report efficacy and tolerability in a series of 10 patients treated off-label with TMZ maintenance after completion of R-MPV (rituximab, methotrexate, procarbazine and vincristine) treatment for or primary diagnosed PCNSL.

RESULTS

Median progression-free survival (PFS) was 57 months, 2-year PFS was 67%, and 5-year PFS was 33%. Median overall survival (OS) was 63 months, 2-year OS was 88%, and 5-year OS was 57%. TMZ was generally well tolerated, with the most common toxicity of Grade 3 or higher being thrombocytopenia in 3 patients (30%).

CONCLUSION

These outcomes suggest that TMZ might have activity for maintenance in elderly patients with PCNSL, when more aggressive treatments are contraindicated.

Assessment of immunohistochemical testing for androgen receptor splice variant 7 as a biomarker to predict resistance to androgen receptor signaling inhibitors in metastatic prostate cancer

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Background: Androgen receptor splice variant 7 (AR-V7) has been shown to confer resistance to androgen receptor signaling inhibitors (ARS-I) such as enzalutamide (enza) and abiraterone (abi). Resistance can be observed at the time of initial treatment, or may be acquired later in the disease course. Prior research has primarily focused on AR-V7 expression in circulating tumor cells (CTCs) but the utility of more affordable immunohistochemical (IHC) testing to predict for primary resistance to ARS-I remains unknown, which is of particular relevance as ARS-I gain use as initial therapy. Methods: We identified patients in the South Texas Veterans Health Administration Tumor Registry with metastatic, castrate-resistant prostate cancer who received ARS-I since 2011. IHC for AR-V7 staining was validated on controls and performed on tissue from the most recent tissue specimen (diagnostic biopsy, prostatectomy, or biopsy of a metastatic site) on all identified patients with adequate tissue available. Results: 25 of 42 (60%) patients receiving abi had PSA response with median duration of response (DOR) of 231 days. 14 of 26 (54%) of patients receiving enza experienced PSA response with a median DOR of 165 days. IHC is currently being interpreted on stored tissue specimens to assess predictive efficacy of AR-V7 staining. The de-novo rate of AR-V7 expression and correlation with response to ARS-I in the veteran population will be reported with final results. Conclusions: IHC testing for AR-V7 may provide a cost-effective biomarker to identify patients resistant to ARS-I, thus avoiding thus avoiding time-consuming and costly treatment with ineffective therapy. Further study is warranted to assess cost-effectiveness and reduction in unnecessary toxicity by the use of IHC testing for AR-V7 in the front-line setting to predict primary resistance for patients that would otherwise qualify for ARS-I.

Delays in treatment for colorectal cancer patients in an NCI-designated cancer center serving a Hispanic majority community

e18233

Background: Timeliness of cancer treatment is an important aspect of health care quality. Colorectal cancer (CRC) care requires the coordinated multidisciplinary effort of various aspects of the health care system, which can lead to delays between initial diagnoses to definitive therapy. Little is known about the time from diagnosis to cancer-directed treatment, neither about the factors that cause delays or its effect on patient outcomes. Delays to curative surgery beyond 12 weeks are associated with increased mortality in CRC. Longer time to adjuvant chemotherapy is associated with worse survival among patients with resected CRC. The objective of our study is to identify delays in initiation of CRC treatment and its causative factors. Methods: We retrospectively reviewed the medical records of CRC patients who were either initially diagnosed or had initial surgical resection at University Hospital and had further treatment at Cancer Therapy and Research Center, between 7/1/2010 and 12/22/2014. Data were collected on patient and disease characteristics, treatment timelines and outcomes, till pre-specified data cut-off date of 8/1/16. Results: Of 256 patients treated for CRC, majority were males (59 %), Hispanic (59 % ) and uninsured (34 %). Most had non-metastatic disease (70%). 72 % were still alive at the time of data cut-off. The median time from diagnosis to treatment (TDT) was 21 days, with most of te patients getting first treatment between 0-30 days of diagnosis (60 %). Median time from first treatment to first progression or recurrence was 12 months (range 0.9- 42 mos.). Median overall survival (OS) was 17 months (0.1- 51 months). There were no statistically significant difference between the progression or recurrence free survival and OS in patients with TDT < 30 days, 30-89 days and > 90 days. Compared to non-Hispanics, Hispanic patients were more likely to have a TDT of 31-89 days (31% vs 37%, p = 0.0003) and > / = 90 days (3% vs 7%, p = 0.0001). Conclusions: Hispanic patients were more likely to have a longer time from diagnosis to treatment compared to non-Hispanic patients. The factors for such disparities in health care quality and their effect on survival needs to be explored further.

Delays in treatment for colorectal cancer patients in an NCI-designated cancer center serving a Hispanic majority community

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Background: Timeliness of cancer treatment is an important aspect of health care quality. Colorectal cancer (CRC) care requires the coordinated multidisciplinary effort of various aspects of the health care system, which can lead to delays between initial diagnoses to definitive therapy. Little is known about the time from diagnosis to cancer-directed treatment, neither about the factors that cause delays or its effect on patient outcomes. Delays to curative surgery beyond 12 weeks are associated with increased mortality in CRC. Longer time to adjuvant chemotherapy is associated with worse survival among patients with resected CRC. The objective of our study is to identify delays in initiation of CRC treatment and its causative factors. Methods: We retrospectively reviewed the medical records of colorectal cancer patients who were either initially diagnosed or had initial surgical resection at University Hospital and had further treatment at Cancer Therapy and Research Center, between 7/1/2010 and 12/22/2014. Data were collected on patient and disease characteristics, treatment timelines and outcomes, till pre-specified data cut-off date of 8/1/16. Results: Of 256 patients treated for CRC, 59 % were males, 59 % Hispanic, and 34 % were uninsured. Most had non-metastatic disease (70%). 72 % were still alive at the time of data cut-off. The median time from diagnosis to treatment (TDT) was 21 days, with 60 % between 0-30 days and 59 % between 31-89 days. Median time from first treatment to first progression or recurrence was 12 months (range 0.9- 42 mos.). Median overall survival (OS) was 17 months (0.1- 51 months). There were no statistically significant difference between the progression or recurrence free survival and OS in patients with TDT <30 days, 30-89 days and >90 days. Compared to non-Hispanics, Hispanic patients were more likely to have a TDT of 31-89 days (31% vs 37%, p= 0.0003) and >/= 90 days (3% vs 7%, p= 0.0001). Conclusions: Hispanic patients were more likely to have a longer time from diagnosis to treatment compared to non-Hispanic patients. The various factors for such disparities in health care quality and their effect on survival needs to be explored further.

Changes in renal function following treatment for ovarian cancer

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Background: Among women treated for Epithelial Ovarian Cancer (EOC), new or worsening renal dysfunction has been observed but not systematically studied. We conducted a retrospective cohort study to estimate the rate of decline in renal function following a diagnosis of EOC, compared with the rate of decline among the same patients prior to diagnosis. Methods: We study a historical cohort of women diagnosed with EOC between 1/1/2000 and 12/31/2011, who received health care services within a large community medical center. Data were retrieved from institutional electronic records. We develop a Generalized Estimating Equations (GEE) model to quantify changes in estimated glomerular filtration rate (eGFR) over time, with the date of EOC diagnosis as the reference point (time zero). All analyses were conducted using SAS version 9.2 (SAS Institute Inc., Carey, NC). Results: The cohort is comprised of of 323 women. At diagnosis, the mean age was 63.4 (± 13.5) years and the mean eGFR was 81.0 (± 22.7). There were 74 (22.9%) patients carrying a diagnosis of hypertension, 25 (7.7%) with diabetes, and 73 (22.6%) who were clinical obese. Prior to EOC diagnosis the decline in mean monthly eGFR was not significant (- 0.052, 95% CI -0.11-0.009, p = 0.092), after controlling for age, obesity, hypertension, and diabetes. This monthly decline increased by almost 4-fold (p = 0.0007) subsequent to EOC diagnosis. To discern the potential effect of chemotherapy on renal function, we conducted a secondary analysis on the 120 women for whom detailed chemotherapeutic data is available. For women who received standard first-line chemotherapy (paclitaxel and carboplatin) the rate of eGFR decline increased 10-fold (-0.025 vs. -0.25, p = .0066) relative to their baseline rate of decline. For those who received other regimens, the increase was 11.4 times (-0.025 vs. -0.286, p =.0011); this was not significantly higher than those receiving the standard regimen (p = 0.72). Conclusions: This ongoing study suggests that women treated for EOC suffer an accelerated rate of renal function decline, independent of major comorbid conditions, that is therefore attributable to the disease and/or its treatment.

Fungal melanin detection by the use of copper sulfide-silver

Silver-staining procedures were investigated for their effectiveness in identifying cell wall-based fungal melanins in live and fixed plastic embedded samples, particularly 1,8-dihydroxynaphthalene (DHN) based polyketide melanins. We developed a simple and reliable melanin-staining technique based on a silver accumulation method originally published for histological demonstration of heavy metal sulfides in mammalian tissues. Copper is bound to fungal melanin followed by formation of the copper sulfide at melanin sites in fungal cell walls, which then are amplified into vivid black stains using a silver enhancement step. The method demonstrates patterns of melanization in a range of fungal hyphae and is suitable for light and electron microscopy. Albino mutant fungi and normally nonmelanized fungi do not stain with the sulfide-silver technique. Mammalian melanocytes also were labeled by the technique, indicating its universality as a melanin probe.

Deletion of scbA enhances antibiotic production in Streptomyces lividans

Antibiotic production in many streptomycetes is influenced by extracellular gamma-butyrolactone signalling molecules. In this study, the gene scbA, which had been shown previously to be involved in the synthesis of the gamma-butyrolactone SCB1 in Streptomyces coelicolor A3(2), was deleted from the chromosome of Streptomyces lividans 66. Deletion of scbA eliminated the production of the antibiotic stimulatory activity previously associated with SCB1 in S. coelicolor. When the S. lividans scbA mutant was transformed with a multi-copy plasmid carrying the gene encoding the pathway-specific activator for either actinorhodin or undecylprodigiosin biosynthesis, production of the corresponding antibiotic was elevated significantly compared to the corresponding scbA(+) strain carrying the same plasmid. Consequently, deletion of scbA may be useful in combination with other strategies to construct host strains capable of improved bioactive metabolite production.

Membrane type 1 matrix metalloproteinase and gelatinase A synergistically degrade type 1 collagen in a cell model

A fibrosarcoma cell line transfected with the matrix metalloproteinase MT1 MMP showed an enhanced ability to degrade 14C-labelled collagen films. As previously shown for proMMP 2 activation, TIMP 1 was an ineffective inhibitor of the process of collagenolysis whereas TIMP 2 was efficient and completely prevented collagen degradation. In the presence of the calcium ionophore, ionomycin, proteolytic processing of MT1 MMP was restricted and collagenolysis did not occur indicating that the 63 kDa form of the enzyme is not a functional collagenase. The collagenolytic activity of MT1 MMP was shown to be enhanced by the addition of proMMP 2, but TIMP 1 inhibition remained poor relative to that of TIMP 2. The study demonstrated that synergy between two non-conventional collagenases effectively degrades insoluble pericellular collagen. Due to the membrane localisation of MT1 MMP, this could potentially occur in a highly localised manner.

Induction of Fas ligand-mediated apoptosis by interferon-alpha

Interferon-alpha (IFN-alpha) was among the first cytokines studied and the earliest to be used in clinical medicine for the treatment of viral infections and malignancies. Although the capacity of IFN-alpha to augment NK cell cytotoxicity against virus-infected target cells or tumor cells is well established, the mechanism has not been fully elucidated. Here we report that IFN-alpha stimulation of PBMC from healthy donors induces Fas (CD95) ligand (FasL) transcription and leads to increased cell surface FasL expression exclusively on the NK cell fraction. Furthermore, IFN-alpha augments the FasL-mediated cytotoxicity of normal PBMC against Fas-sensitive lymphoid tumor cells. In the context of innate immunity, induction of FasL by IFN-alpha can be viewed as an efficient mechanism to potentiate NK cell cytotoxicity in the presence of harmful targets, such as virally infected or transformed cells.

Analysis of a ptsH homologue from Streptomyces coelicolor A3(2)

A ptsH homologue of Streptomyces coelicolor A3(2) was identified in the emerging genome sequence, cloned in Escherichia coli and the S. coelicolor HPr over-produced and purified. The protein was phosphorylated in vitro in a phosphoenolpyruvate (PEP)-dependent manner by purified enzyme I (EI) from Bacillus subtilis, and much less efficiently in an ATP-dependent manner by purified HPr kinase, also from B. subtilis. There was no indication of ATP-dependent phosphorylation of the purified protein by cell extracts of either S. coelicolor or Streptomyces lividans. Deletion of the ptsH homologue from the S. coelicolor and S. lividans chromosomes had no effect on growth when fructose was supplied as sole carbon source, and in S. coelicolor it had no effect on glucose repression of agarase and galactokinase synthesis, suggesting that the HPr encoded by this gene does not play an essential role in fructose transport nor a general role in carbon catabolite repression.

Fungal melanins: a review

The relationship of polyketide melanogenesis molecular biology to that of nonmelanin-producing pathways in a wide range of fungi and other organisms is discussed. Analytical methods and fundamental properties of melanins are discussed and fungal melanin properties are compared with those of animal and bacterial melanins. The enzymatic degradation of melanins by lignin peroxidases is described.Key words: fungal melanin, polyketide melanin, DHN melanin, melanin degradation, melanin properties, melanin analysis.

The TIMP2 membrane type 1 metalloproteinase "receptor" regulates the concentration and efficient activation of progelatinase A. A kinetic study

We have used C-terminal domain mutants to further define the role of interactions of progelatinase A and membrane type 1 matrix metalloproteinase (MT1 MMP) in the binding of TIMP2 and in the cell-associated activation of progelatinase A. Soluble constructs of MT1 MMP were used to demonstrate that binding with TIMP2 occurs primarily through N-terminal domain interactions, leaving the C-terminal domain free for interactions with progelatinase A. The rate of autolytic activation of progelatinase A initiated by MT1 MMP cleavage could be potentiated by concentration of the proenzyme by binding to heparin. Residues 568-631 of the progelatinase A C-terminal domain are important in formation of the heparin binding site, since replacement of this region with the corresponding stromelysin-1 sequence abolished binding to heparin and the potentiation of activation. The same region of gelatinase A was required for binding of latent and active enzyme to TIMP2, but residues 418-474 were not important. A similar pattern was seen using cell membrane-associated MT1 MMP; residues 568-631 were required for binding and activation of progelatinase A, whereas residues 418-474 were not. Neither region was required for activation in solution. The addition of TIMP2 to HT1080 membrane preparations expressing MT1 MMP, but depleted of endogenous TIMP2, resulted in potentiation of progelatinase A activation. This effect was dependent upon TIMP2 binding to MT1 MMP rather than at an independent membrane site. Together, the data suggest that TIMP2 forms a receptor with MT1 MMP that regulates the concentration and efficient generation of functionally active gelatinase A.

Cloning and analysis of a gene from Streptomyces lividans 66 encoding a novel secreted protease exhibiting homology to subtilisin BPN'

Amino-terminal degradation has been observed for many of the secreted heterologous proteins produced by S. lividans 66. We, therefore, set out to characterize the relevant proteinases and their genes. A tripeptide chromogenic substrate was used to identify a gene that was shown to encode a secreted protein which removed tripeptides from the amino terminus of extracellular proteins (tripeptidyl aminopeptidase, Tap; Butler et al. 1995). This activity was removed by a homologous gene deletion replacement and the ability of the S. lividans strain to remove N-terminal tripeptides was greatly reduced, but still significant. When the tap-deleted strain was used as a host for the rescreening of a S. lividans 66 genomic DNA library, a number of other genes encoding proteases with aminopeptidase activities were discovered. One clone (P5-4) produced a 45-kDa secreted protein (Ssp), which showed activity against Ala-Pro-Ala-beta-naphthylamide (APA-beta NH-Nap) substrate. Further analysis of the cloned DNA showed an open-reading frame encoding a protein larger than 45 kDa. Direct Edman degradation of the secreted protein confirmed that it was encoded within the cloned DNA and probably processed from a larger precursor. Protein sequence analysis revealed a striking homology to subtilisin BPN' in three regions around the active-site residues suggesting that the protein is a serine protease. As expected, the protease activity was inhibited by phenylmethylsulphonyl fluoride. Mutant strains with most of the ssp gene deleted exhibited reduced activity against APA-beta NH-Nap substrate compared to their non-deleted parental strains.

Intermolecular autolytic cleavage can contribute to the activation of progelatinase A by cell membranes

Membrane-type matrix metalloproteinase (MT-MMP) messenger RNA and protein expression were shown to be elevated in human fibroblasts following treatment with concanavalin A, coincident with the induction of the ability to process progelatinase A. CHO cells transfected with the cDNA for MT-MMP were able to process both wild type progelatinase A and a catalytically inactive mutant, E375A progelatinase A. Both proenzymes were converted to a 68-kDa intermediate (reducing gels) form, but only the wild type enzyme was processed further to a 66-kDa end product. In contrast, both forms of progelatinase were processed via the 68-kDa intermediate to 66 kDa by concanavalin A-stimulated fibroblasts. Further study of the processing of E375A progelatinase A by plasma membrane preparations from concanavalin A-stimulated fibroblasts showed that addition of active gelatinase A enhanced processing to the mature form. It was concluded that cell membrane-mediated activation of progelatinase A could be via a cascade involving both MT-MMP and intermolecular autolytic cleavage.

Isolation and characterization of two genes encoding proteases associated with the mycelium of Streptomyces lividans 66

A strain of Streptomyces lividans 66 deleted for a major tripeptidyl aminopeptidase (Tap) was used as a host to screen an S. lividans genomic library for clones overexpressing activity against the chromogenic substrate Ala-Pro-Ala-beta-naphthylamide. In addition to reisolation of the tap gene, clones representing another locus, slpD, were uncovered. slpD was analyzed by deletion subcloning to localize its functional sequence. Nucleotide sequence determination revealed an open reading frame encoding a 55-kDa protein exhibiting significant amino acid sequence homology to Tap, particularly around the putative active-site serine residue. No secreted protein was observed for strains harboring the slpD clone, but inspection of the predicted protein sequence revealed a putative lipoprotein signal peptide (signal peptidase II type), suggesting a mycelial location for the SlpD proteinase. In an attempt to isolate an endoprotease known to be active against some heterologous proteins, a second clone was isolated by using a longer substrate (t-butyloxycarbonyl [Boc]-APARSPA-beta-naphthylamide) containing a chemical blocking group at the amino terminus to prevent aminopeptidase cleavage. This locus, slpE, appeared to also encode a 55-kDa mycelium-associated (lipoprotein) proteinase, whose predicted protein sequences showed significant amino acid homology to Tap and SlpD, particularly around the putative active-site serine residues. Chromosomal integration and deletion analysis in both the wild-type and Tap-deficient backgrounds appeared to indicate that SlpD was essential for viability and SlpE was required for growth on minimal media.

Cloning and characterization of a gene encoding a secreted tripeptidyl aminopeptidase from Streptomyces lividans 66

The gene encoding a tripeptidyl aminopeptidase (Tap) from Streptomyces lividans was cloned by using a simple agar plate activity assay. Overexpression of the cloned gene results in the production of a secreted protein which has an apparent subunit molecular weight of 55,000 and is responsible for the major amino-terminal degradative activity in culture broths of S. lividans strains. A DNA sequence analysis revealed a potential protein-encoding region of the size expected to encode the observed protein, which contained a sequence that exhibited significant homology around a putative active site serine residue observed for lipases, esterases, and acyl transferases. Preceding the amino terminus of the secreted protein was a predicted signal peptide of 36 amino acids followed by a tripeptide, which could be autocatalytically removed from a secreted Tap precursor. The transcriptional start site for the gene was mapped by primer extension. Mutant strains of S. lividans lacking detectable Tap activity were able to grow and sporulate normally. Cross-species hybridization experiments showed that DNA homologs of the tap gene are present in most of the Streptomyces strains tested.

Non-promoting effects of lean beef in the rat colon carcinogenesis model

Recent epidemiologic studies have implicated red meat consumption as a risk factor for colon cancer in both men and women. However, it has been very difficult to separate the effects of meat as a protein source from the accompanying fat content of the diets analyzed in these studies. Experimental data from rodent feeding trials show mixed results, with no firm conclusions being possible in terms of the colon-cancer promoting effects of meat fat. The goal of the present study was to compare, in an experimental animal model, the effects of beef with casein as a protein source, within the context of a low- and high-fat diet containing either corn oil or beef tallow, on promotion of colon carcinogenesis. Tumors were induced in Sprague-Dawley rats with 1,2-dimethylhydrazine (20 mg/kg body wt for 10 weeks). Two hundred and eighty male weanling rats were randomized to eight dietary treatment groups of a 2x2x2 factorial design with fat source (corn oil vs. beef tallow), fat level (5% vs. 20%), and protein source (very lean beef vs. casein) as the factors. Diets were fed ad libitum before, during and after carcinogen treatment for a total of 27 weeks. At termination of the study, animals were examined for location, size and type of colon or extracolonic lesions. The total incidence and number of colon tumors were significantly lower in the groups fed beef rather than casein. High fat levels, regardless of source, significantly increased the number of colon adenomas. These results demonstrate that when lean beef is used as the protein source in the context of a low-fat diet, fewer intestinal tumors develop. These data do not support the belief that red meat consumption increases the risk for colon carcinogenesis, but underscores the importance of fat level in dietary context.

Domestic violence: a nursing imperative

This manuscript describes female partner abuse and reviews its significance to health care providers. Attention is given to the essential nursing roles of screening for abuse, intervening with women at risk for abuse, and completing a needed examination when abuse has occurred. Ideas for an expanded nursing role are provided.

The aminopeptidase N-encoding pepN gene of Streptomyces lividans 66

The gene (pepN) encoding an aminopeptidase N (PepN) has been cloned from Streptomyces lividans. This was done using either leucine-beta-naphthylamide or arginine-beta-naphthylamide in a liquid overlayer on colonies growing on agar medium to screen for overproduction of the ability to hydrolyse the substrates. The nucleotide sequence of pepN was determined and shown to encode a 95-kDa protein, which displayed significant homology to PepN proteins from other organisms. Analysis of the overproduced proteinase confirmed that this protein was located intracellularly as a monomeric active species. PepN is a metallo-exopeptidase cleaving next to Leu, Arg and Lys in peptide-bond-containing substrates.

Sequences of the oxytetracycline polyketide synthase-encoding otc genes from Streptomyces rimosus

The complete nucleotide sequences of the Streptomyces rimosus oxytetracycline (oxyTc) polyketide synthase (PKS)-encoding genes (otcY) has been determined, revealing three open reading frames. The deduced amino-acid sequences correspond to the presumed heterodimeric beta-ketoacyl synthase and acyl carrier protein found in other type-II (multicomponent) PKS systems that specify construction of acetate-derived polyketide antibiotics.

Intracellular aminopeptidases in Streptomyces lividans 66

We have investigated the aminopeptidase activities present in Streptomyces lividans strains. The majority of these activities proved to be intracellular with multiple active species. Two aminopeptidase P genes were identified to be responsible for the ability to hydrolyze amino terminal peptide bonds adjacent to proline residues. Two other broad spectrum aminopeptidases were found to display homology at both the DNA and protein levels. One showed significant homology to PepN proteins, particularly around the putative zinc-binding residues which are important for catalysis. The second broad spectrum activity was not analyzed in detail but showed a different spectrum of substrate specificity to that of PepN.

Cloning and characterisation of an aminopeptidase P-encoding gene from Streptomyces lividans

An aminopeptidase P (PepP)-encoding gene has been cloned from Streptomyces lividans 66 by screening for overexpression of activity using the chromogenic substrate Gly-Pro-beta-naphthylamide as a liquid overlayer on colonies growing on agar medium. The pepP gene was localised by deletion mapping, and the nucleotide sequence was determined. The deduced amino acid sequence was found to display significant similarity to Escherichia coli PepP. The partially purified S. lividans enzyme had a 50-kDa subunit and was present as a homodimer. Direct Edman degradation of the purified protein confirmed that pepP encoded the observed intracellular PepP.

Cloning of genetic loci involved in endoprotease activity in Streptomyces lividans 66: a novel neutral protease gene with an adjacent divergent putative regulatory gene

A skimmed-milk clearing assay was used to identify, in a multicopy Streptomyces lividans 66 genomic library, DNA fragments that lead to increased expression of protease activity in S. lividans 66. Three independent loci were identified. The majority class (slpA, which represented 68 of 71 clones) produced large zones of clearing. Two other classes (designated slpB and slpC) showed smaller zones than slpA. Subcloning and deletion analysis of the slpA locus delineated the relevant DNA to within a 2.5 kilobase pair fragment. DNA sequence analysis revealed a structural gene associated with the appearance of an extracellular protein in the culture medium. The derived amino acid sequence indicated the presence of a zinc-binding motif, which was previously noted to be characteristic of metalloprotease enzymes. However, the relatively small size of the protein (apparent molecular weight 20,000-24,000) suggests that it represents a novel class of neutral proteases distinct from the thermolysin-type enzymes. An adjacent divergent open reading frame was identified and shown to cause a significant increase in protease activity when present together with the protease structural gene on a multicopy plasmid in S. lividans 66. The derived amino acid sequence of this open reading frame showed homology with previously characterized regulatory proteins of the LysR family of transcriptional regulator proteins.

Characterization of an oxytetracycline-resistance gene, otrA, of Streptomyces rimosus

The sequence of a 2657 bp DNA fragment containing the coding and regulatory regions of the oxytetracycline (OTC)-resistance gene, otrA, from the OTC producer Streptomyces rimosus was determined. The predicted amino acid sequence of OtrA had extensive identity with tetracycline-resistance genes from other bacteria which mediate resistance via non-covalent ribosomal modification. The N-terminal domain had extremely high identity with the GTP-binding sites of elongation factors, such as EF-G and EF-Tu, suggesting that binding and hydrolysis of GTP is important to the function of the protein. Significant identity with EF-G was present throughout the polypeptide. Transcriptional activity upstream of the otrA coding region was investigated. An Escherichia coli-type promoter, otrAp1, was identified. Transcriptional readthrough of otrA from the upstream gene (otcZ) was also detected in S. rimosus cultures. A divergent promoter activity was identified with subclones of the OtrA fragment in promoter probe vectors analysed in Streptomyces lividans. However, this activity was not identified in a subclone containing more than half of the otrA coding sequence in S. lividans or at all in S. rimosus, indicating that OtrA negatively regulates the expression of the divergent transcript. The data are consistent with regulation of antibiotic production by OtrA to prevent 'suicide'.

Beyond abuse: Parse's theory in practice

A nursing practice with abused women and their families based on Parse's theory of Man-Living-Health is described with emphasis on implementation of the practice processes flowing from the theory and common outcomes of the processes. A case study is presented to illustrate how the practice processes aided one couple in transforming from an abusive relationship to a new and valued way of coexisting. Information on the nursing practice and the case study are used to help demonstrate the utility of the theory of Man-Living-Health in enhancing the quality of life.

Cloning and heterologous expression in Streptomyces lividans of Streptomyces rimosus genes involved in oxytetracycline biosynthesis

The anhydrotetracycline (ATC) oxygenase enzyme which carries out the conversion of ATC to dehydrotetracycline was purified and the N-terminal amino acid sequence was determined. The sequence displays a significant similarity to that of the p-hydroxybenzoate hydroxylase from Pseudomonas fluorescens. This is consistent with the activity of the oxygenase, i.e., addition of a hydroxyl moiety to an aromatic ring structure. Oligonucleotide probes were designed and used to clone the corresponding fragment of chromosomal DNA from Streptomyces rimosus. This DNA fragment was used to screen a cosmid library, allowing the isolation of flanking DNA sequences. Surprisingly, the gene was located within the previously cloned cluster of genes involved in the synthesis of the biosynthetic intermediate ATC and not as had been expected (P. M. Rhodes, N. Winskill, E. J. Friend, and M. Warren, J. Gen. Microbiol. 124:329-338, 1981) at a separate locus on the other side of the chromosome. Subcloning of an appropriate DNA fragment from one of the cosmid clones onto pIJ916 produced Streptomyces lividans transformants which synthesized oxytetracycline.

Molecular cloning of resistance genes and architecture of a linked gene cluster involved in biosynthesis of oxytetracycline by Streptomyces rimosus

The isolation of mutants of Streptomyces rimosus which were blocked in oxytetracycline (OTC) production was described previously. The genes for the early steps of antibiotic biosynthesis mapped together. Genomic DNA fragments of S. rimosus which conferred resistance to OTC and complemented all of these non-producing mutants have been cloned. The cloned DNA is physically linked within approximately 30 kb of the genome of S. rimosus. The gene cluster is flanked at each end by a resistance gene each of which, independently, can confer resistance to the antibiotic. In OTC-sensitive strains of S. rimosus, the entire gene cluster including both resistance genes has been deleted. Complementation of blocked mutants by cloned DNA fragments in multi-copy vectors was often masked by a secondary effect of switching off antibiotic production in strains otherwise competent to produce OTC. This adverse effect on OTC production was not observed with recombinants using low copy-number vectors.

Family transformation: Parse's theory in practice

This article illustrates how the principles and practice dimensions of the theory of man-living-health were used to change the health situation of a family facing the loss of the family patriarch who had experienced major neurosurgery. Theoretical structures from the theory of man- living-health are elucidated through describing nursing care with the family. The article demonstrates the value of theory-based nursing prac tice by describing how care based on the theory of man-living-health transformed a family situation as the family members struggled to live their value priorities.

The use of N,N,N',N'-tetramethylphenylenediamine to detect peroxidase activity on polyacrylamide electrophoresis gels

N,N,N',N'-Tetramethylphenylenediamine (TMPD) acts as an effective indicator of peroxidase activity on polyacrylamide electrophoresis gels. The test is easy to perform, rapid, sensitive, and reliable. The procedure produces vivid bright blue bands (Wursters blue) on a clear background. TMPD and Wursters blue did not interfere with a number of other electrophoresis stains subsequently applied. These included total protein staining with Coomassie blue, and a number of pigment producing electrophoresis stains used to investigate melanogenesis-related enzymes in the black yeast Phaeococcomyces sp.

Homology between Streptomyces genes coding for synthesis of different polyketides used to clone antibiotic biosynthetic genes

Many important antibiotics such as tetracyclines, erythromycin, adriamycin, monensin, rifamycin and avermectins are polyketides. In their biosynthesis, multifunctional synthases catalyse iterated condensation of thio-esters derived from acetate, propionate or butyrate to yield aliphatic chains of varying length and carrying different alkyl substituents. Subsequent modifications, including aromatic or macrolide ring closure or specific methylations or glycosylations, generate further chemical diversity. It has been suggested that, if different polyketide synthases had a common evolutionary origin, cloned DNA coding for one synthase might be used as a hybridization probe for the isolation of others. We show here that this is indeed possible. Study of a range of such synthase genes and their products should help to elucidate what determines the choice and order of condensation of different residues in polyketide assembly, and might yield, by in vitro recombination or mutagenesis, synthase genes capable of producing novel antibiotics. Moreover, because genes for entire antibiotic pathways are usually clustered in Streptomyces, cloned polyketide synthase genes are valuable in giving access to groups of linked biosynthetic genes.

Properties of in vitro recombinant derivatives of pJV1, a multi-copy plasmid from Streptomyces phaeochromogenes

The 10.8 kb plasmid pJV1, isolated from Streptomyces phaeochromogenes, has a high copy number (about 150) and a broad host range among Streptomyces spp. Several pJV1 derivatives carrying the thiostrepton resistance gene (tsr) of S. azureus were made. One derivative, pWOR191, was shown to promote its own transfer and to mobilize chromosomal markers in S. lividans. Another derivative, pWOR109, was non-transmissible. Deletion in vitro of a segment of pWOR109 gave pWOR120 (5.6 kb), which has single BamHI and Bg/II sites shown to be capable of accepting 'foreign' DNA such as a previously cloned S. antibioticus DNA fragment encoding tyrosinase, giving vectors (pWOR125, pWOR126) with properties resembling the well-established multicopy vector pIJ702. Shuttle vectors capable of functioning in both S. lividans and Escherichia coli were also constructed. The region of pJV1 essential for replication and maintenance was localized to a 2.5 kb segment. Stable maintenance of pWOR109 and pWOR120 was observed in the presence of derivatives of pIJ101, the progenitor of pIJ702.

Nonhemorrhagic cerebral infarction in young adults

We evaluated 144 patients (81 males and 63 females) aged 15 to 45 years who had nonhemorrhagic cerebral infarction. Atherosclerotic cerebral infarction was diagnosed in 38 patients. Potential cardiac causes of cerebral embolism were found in 33 patients. Only three events could be attributed to mitral valve prolapse. Hematologically related disorders were diagnosed in 21 patients, while 38 patients had nonatherosclerotic vasculopathies. Young patients with cerebral infarction are a heterogeneous group. A potential cause can be found in most patients. We found more than 40 possible etiologies among our patients. Mitral valve prolapse apparently is not a common cause of cerebral infarction among young adults. Cerebral infarction should not be ascribed to oral contraceptives or migraine until other possible causes have been eliminated.

Echocardiographic evaluation of young adults with nonhemorrhagic cerebral infarction

We reviewed echocardiographic findings in patients aged 15 to 45 years with acute nonhemorrhagic cerebral infarction (NHCI). Among 132 patients with NHCI, 96 (72.7%) had M-mode and two-dimensional echocardiography, including contrast echocardiography with intravenous saline injection when clinically indicated. Echocardiograms were abnormal in 33 patients. Of these, 7 had other conditions that could cause NHCI. Echocardiography corroborated the clinical diagnosis of a cardiogenic source for cerebral infarction in 17 others. The other 9 had no other clues for cardiovascular disease. Potential etiologies of NHCI diagnosed by echocardiography in these 9 cases included: paradoxical embolism, 5 patients; right atrial myxoma, 1; rheumatic mitral valve vegetation, 1; myxomatous mitral valve (marantic endocarditis at postmortem), 1; and left atrial enlargement associated with decreased left ventricular function, 1. Routine echocardiography frequently conveys useful information in patients under age 45 with NHCI. In young patients with cerebral embolism of unknown etiology if routine M-mode and two dimensional echocardiographic studies are normal, contrast echocardiographic studies should be performed to rule out intracardiac shunts and the possibility of paradoxical cerebral embolism.

A dose-escalation study of large doses of naloxone for treatment of patients with acute cerebral ischemia

A dose-escalation study was performed in 27 patients to determine the highest safe and potentially optimal dose of naloxone for treatment of acute cerebral ischemia. All patients received a bolus of naloxone followed by a continuous 24 hour infusion at an hourly rate 50% of the bolus. Loading doses ranged from 2.5 to 200 mg/m2. Total patient doses ranged from 52.3 to 4978 mg. No major dose-related side effects occurred. This study was not designed to determine naloxone's efficacy in stroke, but transient or sustained improvement was observed in 13 patients. Three patients' neurological condition worsened within three hours after the naloxone was discontinued. Our experience suggests that further therapeutic trials of naloxone are worthwhile.

Intramuscular acupuncture-like electrical stimulation inhibits stretch reflexes in contralateral finger extensor muscles

Electro-acupuncture is one of many physical measures used to relieve musculoskeletal pain and to improve the associated restricted range of motion. Experiments were designed to determine whether or not acupuncture-like stimulation inhibits stretch reflexes in an arm extensor muscle in human volunteers. Surface electromyographic recordings were made on the right extensor digitorum communis muscle and averaging techniques were used to study the reflex responses to brief deflection of the finger with a solenoid-driven probe. The ratio M1:M2 of two components of the reflex was reduced during continuous acupuncture-like stimulation of the contralateral first dorsal interosseus and extensor digitorum communis muscles near their motor points (acupuncture points LI 4 and LI 11). Concomitant changes in skin temperature were observed on the forehead and in the arm in which acupuncture-like stimulation was used. In control experiments, when the acupuncture needles were inserted subcutaneously and stimulated with the same current parameters at distinctly uncomfortable intensities, no change in the reflexes occurred. These findings show that acupuncture-like stimulation exerts physiologic effects on the central nervous system, mediated presumably by muscle afferent fibers. The effects may be relevant to relief of muscle spasm and musculoskeletal pain, and restoration of mobility.

Aphasia following pluridirectional tomography with metrizamide. The effect of patient position

Eight of 67 patients became transiently aphasic after myelography or cisternography with metrizamide. All eight patients had been placed in the left lateral decubitus position for pluridirectional tomography. Immediate EEGs revealed focal left-sided abnormalities in two patients. In one other patient, a computed tomographic scan showed contrast mainly over the left hemisphere. All of the symptoms resolved within 48 hours. In 34 patients who were placed on the right side, no language disturbance was noted. Aphasia after pluridirectional tomography with metrizamide may be due to local irritation of the perisylvian language centers of the dominant hemisphere. The phenomenon is distinct from syndromes of generalized confusion. The complication may be avoided by placing patients in a right lateral decubitus position for pluridirectional tomography.

Irradiation injury to large arteries

Four cases of irradiation injury to large arteries are presented and the literature is reviewed. Three patterns of injury have emerged. 1. Intimal damage resulting in mural thrombosis presenting within 5 years of irradiation. 2. Fibrotic occlusion presenting within 10 years of injury. 3. A predisposition to the development of atheroma together with periarterial fibrosis associated with a latent interval of 20 or more years. The treatment of choice is a bypass procedure of the arterial lesion.

A follow-up study of 48 patients with Reiter's syndrome

A follow-up study of 48 patients with Reiter's syndrome was carried out in an attempt to clarify the clinical course of the disease. The mean age at the onset of Reiter's syndrome was 27.1 years (range 15 to 52 years) and when seen at follow-up 32.5 years (range 19 to 58 years). The average time from the onset of the first attack of peripheral arthritis to the time of follow-up was six and a half years (range 0.5 to 27 years). Only three patients had diarrhea prior to the onset of Reiter's syndrome. At follow-up 22 per cent of the patients were asymptomatic, 24 per cent had recurrent minor symptoms, 24 per cent had recurrent moderate symptoms, and 30 per cent had recurrent major symptoms. However, even in the last group, all patients were in functional classes 1 or 2 between the flares of disease. No patients in the series were in functional class 3 or 4, and 30 per cent were in class 1.