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.

Modified frailty index predicts early outcomes after colorectal surgery: an ACS-NSQIP study

AIM

Frailty is defined as a decrease in physiological reserve with increased risk of morbidity following significant physiological stressors. This study examines the predictive power of the five-item modified frailty index (5-mFI) in predicting outcomes in colorectal surgery patients.

METHODS

The American College of Surgeons National Surgical Quality Improvement Program Database was queried from 2011 to 2016 to determine the predictive power of 5-mFI in patients who had colorectal surgery.

RESULTS

Of 295 490 patients, 45.8% had a score of 0, 36.2% had a score of 1 and 18% had a score of ≥ 2. On univariate analysis, frailer patients had significantly greater incidences for overall morbidity, serious morbidity, mortality, prolonged length of hospital stay, discharge to a facility other than home, reoperation and unplanned readmission. These findings were consistent on multivariate analysis where the frailest patients had greater odds of postoperative overall morbidity (OR 1.39; 95% CI 1.35-1.43), serious morbidity (OR 1.39; 95% CI 1.33-1.45), mortality (OR 2.00; 95% CI 1.87-2.14), prolonged length of hospital stay (OR 1.24; 95% CI 1.20-1.27), discharge destination to a facility other than home (OR 2.80; 95% CI 2.70-2.90), reoperation (OR 1.17; 95% CI 1.11-1.23) and unplanned readmission (OR 1.31; 95% CI 1.26-1.36). Weighted kappa statistics showed strong agreement between the 5-mFI and 11-mFI (kappa = 0.987, P < 0.001).

CONCLUSIONS

The 5-mFI is a valid and easy to use predictor of 30-day postoperative outcomes after colorectal surgery. This tool may guide the surgeon to proactively recognize frail patients to instigate interventions to optimize them preoperatively.

Carotid interventions (CEA and CAS) in acute stroke patients: which procedure on which patient

Treatment of carotid bifurcation disease in patients presenting with acute stroke has been a controversial issue over the past four decades. Classically, patients were asked to wait four to six weeks before intervention was entertained in order for the brain to stabilize and the risks of intervention to be minimized. Unfortunately, up to 20% of patients will have a secondary event after their index event and the window of opportunity to save, potentially salvageable ischemic tissue will be missed. Early reports had demonstrated poor results with intervention. However, more recently, institutions such as ours have demonstrated excellent result in early intervention in patients who present with stable mild to moderate stroke with an NIH stroke scale less than 15 and preferably less than 10, present with stroke and ipsilateral carotid artery lesion of 50% or greater. Also more recently, we have been aggressively treating patients with larger ulcerative plaques even if the stenosis approaches 50%. In our and others experiences, patients who are treated at institutions that have comprehensive stroke centers (CSCs) where they have a multidisciplinary system that consists of vascular surgeons, neuro interventionalists, stroke neurologists, specifically trained stroke nursing staff and a neuro intensive ICU have had optimal results. Early assessment, diagnosis of stroke with recognition of cause of embolization is mandatory but patient selection is extremely important; finding those patients who will benefit the most from urgent intervention. Most studies have demonstrated the benefit of carotid endarterectomy in these patients. More recent studies have demonstrated acceptable results with carotid stenting, especially in smaller lesions, those less than 1.2 centimeters. Early intervention should be avoided in most patients who are obtunded or with an NIH stroke scale greater than 15 or who do not have any "brain at risk" to salvage. These patients may be better served by being treated medically than those small group of patients that do have some improvement may benefit from interval intervention.

Characterization of an anti-rainbow trout (Oncorhynchus mykiss) CD3ε monoclonal antibody

This study characterizes a monoclonal antibody (mAb) produced against the cytoplasmic tail region of the epsilon chain of the CD3 (CD3ε) transmembrane protein found on T lymphocytes of rainbow trout (Oncorhynchus mykiss). Flow cytometry and fluorescent microscopy conducted on trout leukocytes with the anti-trout CD3ε mAb showed a distinctive population of IgM(-) CD3e(+) lymphocytes fitting the expected profile of T-cells. Immunoprecipitation of lysates derived from trout lymphocytes revealed a 19 kDa protein and peptide analysis confirmed its specificity for CD3ɛ. In vitro proliferation assays with T-cell mitogens, ConA and PHA, resulted in a 3 fold increase in the percentage of CD3ɛ+ lymphocytes compared to LPS and control cultures. The mAb characterized in this study will be useful in further elucidation for both the role and distribution of T lymphocytes in the teleost immune system.

Focus Issue on Squamous Cell Carcinoma: Practical Concerns Regarding the 7th Edition AJCC Staging Guidelines

The 7th edition of the AJCC Cancer Staging Manual represents a dramatic shift in the way that cutaneous squamous cell carcinoma (cSCC) is staged, in that it is first attempt to incorporate evidence-based medicine into the staging guidelines for cSCC. In our opinion, the changes made to the seventh edition represent a significant improvement over previous editions and will ultimately lead to improved patient stratification, more accurate prognostic data, and a better framework to guide clinical decision making. However, there are a number of issues within the latest guidelines that require clarification or are impractical for clinical practice. The purpose of this paper is to highlight the key changes to the 6th edition staging manual as they pertain to cSCC, to point out impractical component of the 7th edition and/or aspects that require further clarification, and to make recommendations that address any current shortcomings to improve subsequent editions. Specific focus will be given to the inclusion of separate guidelines for cSCC and Merkel cell carcinoma (MCC), the incorporation of high-risk factors as modifiers of T stage, the addition of new guidelines for advanced T stage, and the changes in stratification of lymph node status. This paper is modified from a more comprehensive treatment of the staging of nonmelanoma skin cancer by Warner and Cockerell entitled "The new 7th edition American joint committee on cancer staging of cutaneous nonmelanoma skin cancer: a critical review," in the American Journal of Clinical Dermatology (paper accepted, pending publication).

Restriction fragment length polymorphism analysis of major histocompatibility complex class II genes from inbred chicken lines

High molecular weight DNA was extracted from sperm from chickens of 14 inbred lines. The DNA was digested with each of four restriction enzymes (Pvu II, Hind III, Bgl II, and Bam HI), electrophoresed for 18 or 45 h, blotted onto nitrocellulose, and hybridized to a chicken major histocompatibility complex (MHC, B complex) class II beta-chain probe (beta 2-exon specific). Restriction fragment length polymorphisms (RFLPs) were found with each of the restriction enzymes used. Birds with the same B haplotype always showed the same RFLP pattern; however, some birds of different B haplotypes also shared the same RFLP pattern. To test for the Mendelian inheritance of the RFLP patterns, the F2 progeny of an informative cross were analysed. The RFLP patterns corresponded with the serologically determined B haplotypes of the F2 birds, thereby showing the Mendelian inheritance of the polymorphic bands.

In vitro imaging of embryonic stem cells using multiphoton luminescence of gold nanoparticles

Recent advances in nonlinear optical techniques and materials such as quantum wells, nanowires and noble-metal nanoparticles have led to advances in cellular imaging wherein various nanoparticles have been shown to improve both in vitro and in vivo visualization. In this paper, we demonstrate in vitro imaging using multi-photon photoluminescence of gold nanoparticles from two different cell types Dictyostelium discoideum and mouse embryonic stem cells. By observing nanoparticles we show that embryonic stem cells maintained their ability to proliferate for several passages while grown in the presence of gold nanoparticles. The advantages of multi-photon luminescence using gold nanoparticles have important implications for use in stem cell proliferation experiments and in vitro experiments to monitor differentiation.

The use of the orthopaedic perioperative autotransfusion (OrthoPAT) system in total joint replacement surgery

Management of blood loss in orthopaedic surgery has evolved over the years. New approaches to making blood safer for patients has involved the use of preoperative autologous donation, the use of epoetin alfa administered preoperatively, intraoperative salvage, and perioperative salvage and infusion devices. A new alternative to salvage and infusion devices is the OrthoPAT. This article is meant to introduce the device to the orthopaedic nurse who works in the OR, PACU, and orthopaedic or medical-surgical unit, and who cares for orthopaedic patients who experience significant blood loss in total joint replacement surgery.

Clinical relevance of benign endometrial cells in postmenopausal women

Our objective was to determine if the finding of benign endometrial cells on a Papanicolaou (Pap) smear of a postmenopausal woman is associated with endometrial/uterine pathology, independent of symptomatology and hormone replacement therapy (HRT) status. The medical records of 146 postmenopausal patients who had a Pap smear showing normal-appearing endometrial cells between January 9, 1997 and January 12, 2000 were reviewed. Uterine pathology for each patient was determined by reviewing the results of endometrial sampling (endometrial biopsy or dilatation and curettage), hysterectomy, or pelvic sonogram, which were performed within 24 mo of the cytologic smear. The results were then correlated with clinical symptomatology and HRT status of each patient at the time the cytologic smear was obtained. Of the 146 Pap smears coded with "endometrial cells in a postmenopausal woman," 50 were excluded due to prior hysterectomy, perimenopausal status, and absence of further follow-up. Of the remaining 96 women, 27 (28%) had benign pathologic findings including polyps, leiomyomata, and simple hyperplasia without atypia, whereas 11 (12%) had significant pathologic findings including hyperplasia with atypia, adenocarcinoma, mixed Mullerian tumor, and leiomyosarcoma. Of the 11 patients with significant pathology, only one patient did not have abnormal vaginal bleeding but instead had a 30-wk-size irregular uterus on examination, and only 2 patients received hormone replacement therapy. In conclusion, Reporting endometrial cells on Pap smears in postmenopausal women did not lead to the diagnosis of any cases of significant pathology that would have gone unsuspected clinically. Moreover, HRT status did not affect the incidence of normal endometrial cells on Pap smears in postmenopausal women, nor did it aid in distinguishing which postmenopausal women had endometrial/uterine pathology. This calls into question the usefulness of the current Bethesda guideline to report "benign endometrial cells in a postmenopausal woman."

Human uroporphyrinogen-III synthase: genomic organization, alternative promoters, and erythroid-specific expression

Uroporphyrinogen-III (URO) synthase is the heme biosynthetic enzyme defective in congenital erythropoietic porphyria. The approximately 34-kb human URO-synthase gene (UROS) was isolated, and its organization and tissue-specific expression were determined. The gene had two promoters that generated housekeeping and erythroid-specific transcripts with unique 5'-untranslated sequences (exons 1 and 2A) followed by nine common coding exons (2B to 10). Expression arrays revealed that the housekeeping transcript was present in all tissues, while the erythroid transcript was only in erythropoietic tissues. The housekeeping promoter lacked TATA and SP1 sites, consistent with the observed low level expression in most cells, whereas the erythroid promoter contained GATA1 and NF-E2 sites for erythroid specificity. Luciferase reporter assays demonstrated that the housekeeping promoter was active in both erythroid K562 and HeLa cells, while the erythroid promoter was active only in erythroid cells and its activity was increased during hemin-induced erythroid differentiation. Thus, human URO-synthase expression is regulated during erythropoiesis by an erythroid-specific alternative promoter.

Novel mutations in spastin gene and absence of correlation with age at onset of symptoms

Autosomal dominant hereditary spastic paraplegia is genetically heterogeneous, with at least five loci identified by linkage analysis. Recently, mutations in spastin were identified in SPG4, the most common locus for dominant hereditary spastic paraplegia that was previously mapped to chromosome 2p22. We identified five novel mutations in the spastin gene in five families with SPG4 mutations from North America and Tunisia and showed the absence of correlation between the predicted mutant spastin protein and age at onset of symptoms.

Use of anti-glycoprotein monoclonal antibodies to characterize rabies virus in formalin-fixed tissues

Seventy anti-rabies virus monoclonal antibodies (Mabs) were tested for reactivity with rabies and rabies-related viruses in formalin-fixed (FF) tissues. Forty-three of the Mabs were directed against the glycoprotein and 27 were directed against the nucleocapsid as determined by enzyme immunoassays and neutralization tests. Twenty of the anti-glycoprotein Mabs and one of the anti-nucleocapsid Mabs reacted with the rabies challenge virus strain (CVS) in FF tissue. These 21 Mabs were screened against other lyssaviruses in FF tissues: five rabies virus strains (coyote, skunk, raccoon, red bat, and silver-haired bat), and four rabies-related viruses (Australian bat lyssavirus, Duvenhage virus, Lagos bat virus, and Mokola virus). One of the anti-glycoprotein Mabs was reactive with all the virus strains screened. Another of the anti-glycoprotein Mabs reacted with all of the rabies virus strains tested, but not with any of the rabies-related virus strains tested. The remaining Mabs had reactivity patterns that could be useful for characterizing lyssaviruses in FF tissues.

Altered plasma antioxidant status in subjects with Alzheimer's disease and vascular dementia

OBJECTIVES

Oxygen-free radicals and lipid hydroperoxides may have an aetiological role in the development of lesions in the central nervous system in patients with Alzheimer's disease and in those with vascular dementia. This study aimed to make a cross-sectional comparison of blood markers of oxidative stress in two groups of patients with these disorders and a control group.

DESIGN

Cross-sectional comparative study.

SETTING

Established memory clinics in Cardiff organized by a University Department of Geriatric Medicine within an acute care NHS Trust.

METHODS

Following a dietary assessment, postprandial venous blood samples were obtained from the following: 25 subjects with probable Alzheimer's disease (AD) (mean age 74.3; 10 F, 15 M); 17 subjects with probable vascular dementia (VD) (mean age 75.5; 5 F, 12 M); and 41 controls (mean age 73.4; 24 F, 17 M) for measurement of circulating lipid peroxides (LP), total antioxidant capacity (TAC), vitamin C (VitC), vitamin E (VitE) and beta-carotene (BC).

RESULTS

Plasma levels of VitC were significantly lower in subjects with vascular dementia compared with controls (VD, 6.5 (4.8, 8.2); controls, 10.0 (8.38, 11.6); VD vs controls, p = 0.015), but no significant difference was seen between controls and patients with Alzheimer's disease (AD, mean 8.3 (6.2, 10.4)). VitE levels were significantly lower in subjects with AD compared with controls (31.1 (28.2, 34.0) vs 36.0 (32.8, 39.2), p = 0.035). BC levels were similar in subjects with AD and controls, but significantly elevated in those with VD (AD, 0.28 (0.2, 0.34); VD, 0.40, (0.27, 0.53); controls, 0.28 (0.22, 0.34); VD vs controls, p = 0.046). There were no significant differences in LP or TAC between the three groups.

CONCLUSIONS

Subjects with dementia attributed to Alzheimer's disease or to vascular disease have a degree of disturbance in antioxidant balance which may predispose to increased oxidative stress. This may be a potential therapeutic area for antioxidant supplementation.

Health problems and health actions among community-dwelling older adults: results of a health diary study

This study examined the health problems and health actions reported by a sample of older adults (N = 60) who maintained health diaries over a 4-week period. The diary sample was 78% (n = 47) White; 52% (n = 31) were women, with a mean age of 75 years (SD = 5.3). Content analysis was used to examine the types of health problems reported in the diaries, which health problems were likely to be considered an illness, and what health actions were reported. Respondents reported an average of four different types of health problems over the 4-week diary period. There were differences in symptom reports related to gender, age, or race. The most frequently reported health problems were musculoskeletal problems (n = 38), runny nose and respiratory problems (n = 24), gastrointestinal problems (n = 22), and headaches (n = 22). Only 36% of all health problems were considered to be illnesses. Subjects recorded a number of health actions in response to their health complaints, including over-the-counter (OTC) medication use (83%), prescription medication use (53%), self-care activities (72%), and professional consultation (43%). Specific strategies that subjects used to deal with various health problems, implications of the findings, and the usefulness of health diaries as a clinical tool are discussed.

Effect of intramedullary polymethylmethacrylate and autogenous cancellous bone on healing of frozen segmental allografts

This study was designed to compare bone mineral density, periosteal callus production, new bone formation, bone porosity, histologic appearance, and union of mid-diaphyseal segmental allografts of the femur stabilized with an interlocking nail technique in a canine model 6 months after the procedure. An in vivo study was performed to compare the effects of augmenting interlocking nail fixation with an interlocking nail alone, intramedullary polymethylmethacrylate, intramedullary polymethylmethacrylate and autogenous cancellous bone applied to the periosteal surface of the host-allograft junction, autogenous cancellous bone applied to the endosteal surface of the allograft, autogenous cancellous bone applied to the periosteal surface of the host-allograft junction, and autogenous cancellous bone applied to the periosteal surface of the host-allograft junction and to the endosteal surface of the allograft. There were no differences among treatments for bone mineral density at any time interval. Callus area 4 weeks after the procedure was greater along the lateral and cranial surfaces for treatments with periosteal cancellous bone (p < 0.05). New bone within the allograft segment did not differ among treatments and was reduced compared with the host-allograft junctions (p < 0.05). The amount and quality of bone tissue at the host-allograft junctions were greatest with treatments of intramedullary polymethylmethacrylate and autogenous cancellous bone applied to the periosteal surface of the host-allograft junction and of autogenous cancellous bone applied to the periosteal surface of the host-allograft junction and to the endosteal surface of the allograft (p < 0.05). The rate of bone union was lower, and there was a greater gap (non-bone tissue) remaining between host and allograft bone with treatment involving just intramedullary polymethylmethacrylate than with other treatments (p < 0.05). The results suggest that augmenting interlocking nail fixation with intramedullary polymethylmethacrylate by itself offers no advantage but that a combination of intramedullary polymethylmethacrylate and cancellous bone at the periosteal surface or of cancellous bone within the medullary canal and at the periosteal surface improves the quality of healing at 6 months.

In vitro and in vivo study on the effect of autogenous cancellous bone and intramedullary polymethylmethacrylate on allograft construct strength

An in vitro study was performed to compare the effects of augmenting interlocking nails of one of two diameters (5 or 6 mm) with intramedullary polymethylmethacrylate. Subsequently, an in vivo study was performed to compare the effects of augmenting the interlocking nail with five combinations of intramedullary polymethylmethacrylate and autogenous cancellous bone applied to the periosteal surface or within the medullary canal. Dogs were killed 6 months after the procedure for biomechanical evaluation of the femora in axial compression, mediolateral and craniocaudal bending, and torsion. Results from the in vitro study at the proximal osteotomy indicated the 6-mm interlocking nail with intramedullary polymethylmethacrylate had greater stiffness than the 5-mm interlocking nail without it (p < 0.05). At the distal osteotomy, regardless of the diameter of the interlocking nail, the addition of intramedullary polymethylmethacrylate increased stiffness (p < 0.05). Results from the in vivo study indicated greater global construct stiffness with an interlocking nail alone, an interlocking nail augmented with intramedullary polymethylmethacrylate and cancellous bone at the periosteal surface, and an interlocking nail augmented with cancellous bone within the medullary canal and at the periosteal surface (p < 0.05). At the osteotomy level, the interlocking nail augmented with intramedullary polymethylmethacrylate and cancellous bone at the periosteal surface had greater stiffness than did an interlocking nail alone or an interlocking nail augmented with either intramedullary polymethylmethacrylate, cancellous bone within the medullary canal, or cancellous bone at the periosteal surface (p < 0.05) but produced the same results as an interlocking nail augmented with cancellous bone within the medullary canal and at the periosteal surface. The results suggest that augmenting interlocking nail fixation with intramedullary polymethylmethacrylate by itself offers no advantage but that a combination of intramedullary polymethylmethacrylate and cancellous bone at the periosteal surface improves structural properties at 6 months.

Ooplasmic transfer in mature human oocytes

Ooplasmic transplantation aimed at restoring normal growth in developmentally compromised oocytes and embryos was evaluated in seven couples (eight cycles) with multiple implantation failures. Two approaches were investigated to transfer ooplasm from donor eggs at metaphase II (MII) stage into patient MII eggs: (i) electrofusion of a ooplasmic donor fragment into each patient egg (three cycles), and (ii) direct injection of a small amount of ooplasm from a donor egg into each patient egg (five cycles). Some donor eggs were used multiple times. Donor eggs were divided into two groups, one being used for ooplasmic extraction and the other one for egg donation. Cleaved embryos resulting from the latter were cryopreserved, where numbers and satisfactory development permitted. A second control group consisted of embryos derived from patient eggs after intracytoplasmic sperm injection without ooplasmic transfer. This was performed when sufficient number of eggs were available (n = 5). Donor eggs (n = 40) were evaluated cytogenetically after micromanipulation in order to confirm the presence of chromosomes. One egg was anuclear and the recipient embryos were not transferred. Normal fertilization was significantly higher after injection of ooplasm (63%) in comparison with fusion (23%). Pronuclear anomalies appeared enhanced after fusion with ooplasts. Embryo morphology was not improved in the three cycles with electrofusion and patients did not become pregnant. An improvement in embryo morphology was noted in two patients after injection of ooplasm and both became pregnant, but one miscarried. A third pregnancy was established in the repeat patient, without obvious embryo improvement. One baby was born and the third pregnancy is ongoing with a normal karyotype. Two other patients with male factor infertility had poor embryos after ooplasmic injection, but the donor embryo controls were also poor. The patients did not become pregnant and had no donor embryos frozen. Ooplasmic transfer at the MII stage may be promising in patients with compromised embryos; however, evaluation of ooplasmic anomalies and optimization of techniques will require further investigation prior to widescale application.

Locus heterogeneity, anticipation and reduction of the chromosome 2p minimal candidate region in autosomal dominant familial spastic paraplegia

We examined 11 Caucasian pedigrees with autosomal dominant 'uncomplicated' familial spastic paraplegia (SPG) for linkage to the previously identified loci on chromosomes 2p, 14q and 15q. Chromosome 15q was excluded for all families. Five families showed evidence for linkage to chromosome 2p, one to chromosome 14q, and five families remained indeterminate. Homogeneity analysis of combined chromosome 2p and 14q data gave no evidence for a fourth as yet unidentified SPG locus. Recombination events reduced the chromosome 2p minimum candidate region (MCR) to a 3 cM interval between D2S352 and D2S367 and supported the previously reported 7 cM MCR for chromosome 14q. Age of onset (AO) was highly variable, indicating that subtypes of SPG are more appropriately defined on a genetic basis than by AO. Comparison of AO in parent-child pairs was suggestive of anticipation, with a median difference of 9.0 years (p<0.0001).

Estrogen receptor gene expression in human uterine leiomyomata

Estrogen and progestin are believed to be important physiological regulators of uterine leiomyoma growth. We recently showed that progesterone receptor messenger ribonucleic acid (mRNA) and protein levels are increased in human uterine leiomyomas compared with those in myometrial biopsy tissue obtained from the same patient. To further characterize the molecular mechanisms underlying abnormal growth of uterine leiomyomas, we analyzed biopsy samples of tumor and adjacent normal myometrium for estrogen receptor (ER) gene expression. Northern analysis indicated that ER mRNA levels were increased 1.4-to 12.6-fold in leiomyoma compared with myometrium in all patients examined (n = 11), whereas beta-actin mRNA was not different between the two groups. The size of the primary ER mRNA transcript was 6.2 kilobases in both leiomyoma and myometrium, indicating no gross mutation of the ER gene. An ER protein of 66 kilodaltons was detected by Western blot analysis, and quantitative immunoassay of ER revealed 9448 +/- 1955 fmol/mg DNA in leiomyoma compared to 2827 +/- 979 fmol/mg DNA in myometrial tissue. Scatchard analysis of 17 beta-estradiol binding to cell-free extracts revealed enhanced binding capacity (per mg DNA) in leiomyoma tissue (n = 6) of about 6-fold, whereas ER binding affinity was not substantially different between the leiomyoma and adjacent myometrial tissues. We propose that increased expression of progesterone receptor in leiomyoma is most likely a consequence of overexpression of functional ER that results in increased end-organ sensitivity to estradiol.

Susceptibility of white-tailed deer (Odocoileus virginianus) to infection with Ehrlichia chaffeensis, the etiologic agent of human ehrlichiosis

Although more than 320 cases of human ehrlichiosis have been diagnosed in 27 states since 1986, the reservoir host or hosts remain unknown. Since antibodies reactive to Ehrlichia chaffeensis, the etiologic agent of human ehrlichiosis, have been found in white-tailed deer (Odocoileus virginianus), we experimentally evaluated the susceptibilities of four white-tailed deer to infection with E. chaffeensis and Ehrlichia canis, a closely related species. A fifth deer served as a negative control. Isolation and nested PCR amplification results from peripheral blood indicated that E. chaffeensis circulated for at least 2 weeks. The deer developed antibodies to E. chaffeensis by day 10 after inoculation, but there was no indication of clinical disease. Immunohistochemical staining identified E. chaffeensis within macrophage-type cells in lymph nodes. The deer inoculated with E. canis did not become infected and did not seroconvert. These results indicate that white-tailed deer can support an E. chaffeensis infection with resulting rickettsemia of at least 2 weeks. The resistance to infection and the absence of seroconversion upon exposure to E. canis indicate that antibody responses previously detected among wild deer are not E. canis cross-reactions. The role of deer as competent reservoirs in the life cycle of E. chaffeensis remains to be explored with suspected tick vectors.

Differential phosphorylation of two size forms of the N-type calcium channel alpha 1 subunit which have different COOH termini

Two size forms of the class B N-type calcium channel alpha 1 subunit were recently identified with CNB1, an antipeptide antibody directed against an intracellular loop of this channel (Westenbroek, R.E., Hell, J.W., Warner, C., Dubel, S.J., Snutch, T.P., and Catterall, W.A. (1992) Neuron 9, 1099-1115). To investigate the biochemical differences between these two size forms, the antibodies CNB3 and CNB4 were raised against peptides with sequences corresponding to the COOH-terminal end of the full-length form. Immunoblot experiments demonstrated that both antibodies specifically recognize the longer form of 250 kDa, indicating that the COOH-terminal regions of the two size forms of the class B N-type channel alpha 1 subunit are different. Phosphorylation experiments with immunopurified calcium channels and different second messenger-activated protein kinases revealed that both the 220- and 250-kDa forms of the class B N-type calcium channel alpha 1 subunit are substrates for cAMP-dependent protein kinase, cGMP-dependent protein kinase, and protein kinase C. These three kinases incorporated approximately 1 mol of phosphate/mol of binding sites for omega-conotoxin (omega-CgTx) GVIA, a ligand specific for the N-type calcium channel, and may regulate the activity of both forms in vivo. In contrast, calcium- and calmodulin-dependent protein kinase II (CaM kinase II) phosphorylated only the long form of the class B N-type calcium channel alpha 1 subunit, with a stoichiometry of 0.5 mol of phosphate/mol of total omega-CgTx GVIA binding sites. Specific phosphorylation of the long form of the class B alpha 1 subunit by CaM kinase II may differentially regulate the function of N-type calcium channels containing different size forms of their alpha 1 subunits in vivo.

Identification and differential subcellular localization of the neuronal class C and class D L-type calcium channel alpha 1 subunits

To identify and localize the protein products of genes encoding distinct L-type calcium channels in central neurons, anti-peptide antibodies specific for the class C and class D alpha 1 subunits were produced. Anti-CNC1 directed against class C immunoprecipitated 75% of the L-type channels solubilized from rat cerebral cortex and hippocampus. Anti-CND1 directed against class D immunoprecipitated only 20% of the L-type calcium channels. Immunoblotting revealed two size forms of the class C L-type alpha 1 subunit, LC1 and LC2, and two size forms of the class D L-type alpha 1 subunit, LD1 and LD2. The larger isoforms had apparent molecular masses of approximately 200-210 kD while the smaller isoforms were 180-190 kD, as estimated from electrophoresis in gels polymerized from 5% acrylamide. Immunocytochemical studies using CNC1 and CND1 antibodies revealed that the alpha 1 subunits of both L-type calcium channel subtypes are localized mainly in neuronal cell bodies and proximal dendrites. Relatively dense labeling was observed at the base of major dendrites in many neurons. Staining in more distal dendritic regions was faint or undetectable with CND1, while a more significant level of staining of distal dendrites was observed with CNC1, particularly in the dentate gyrus and the CA2 and CA3 areas of the hippocampus. Class C calcium channels were concentrated in clusters, while class D calcium channels were generally distributed in the cell surface membrane of cell bodies and proximal dendrites. Our results demonstrate multiple size forms and differential localization of two subtypes of L-type calcium channels in the cell bodies and proximal dendrites of central neurons. The differential localization and multiple size forms may allow these two channel subtypes to participate in distinct aspects of electrical signal integration and intracellular calcium signaling in neuronal cell bodies. The preferential localization of these calcium channels in cell bodies and proximal dendrites implies their involvement in regulation of calcium-dependent functions occurring in those cellular compartments such as protein phosphorylation, enzyme activity, and gene expression.

Using patient reports to measure health care system performance

We developed a self-administered patient questionnaire that asks for data concerning the time to receive services (access to care), communication between providers (coordination of care), and follow up after tests and treatment (continuity of care). From these data, we construct rates of performance about the clinical management systems that support provision of these services. Rates of system performance are calculated for indicators using patients' responses to survey questions. These indicators add the number of patients reporting a problem of those patients who have encountered a particular clinical management system. Information derived from 3000 patient questionnaires is matched with data abstracted from health care medical records. The sensitivity and specificity of patient reports are being evaluated for all indicators classified as gold standards for medical records. Indicators considered gold standard items for patient reports are matched for agreement with any information contained in the medical record. Also, patient characteristics associated with accurate reporting is to be assessed using multivariate logistic regression models.

Differential phosphorylation of two size forms of the neuronal class C L-type calcium channel alpha 1 subunit

L-type calcium channels mediate long-lasting calcium currents which are modulated by protein phosphorylation. Using site-directed anti-peptide antibodies, we show that the alpha 1 subunit of the neuronal class C L-type calcium channel from rat brain exists in two size forms. The longer form, LC2, with an apparent molecular mass of 210-235 kDa was phosphorylated in vitro by cAMP-dependent protein kinase (cA-PK), but the shorter form, LC1, with an apparent molecular mass of 190-195 kDa was not a substrate for cA-PK. In contrast, LC1 and LC2 are both substrates for protein kinase C (PKC), calcium- and calmodulin-dependent protein kinase II, and cGMP-dependent protein kinase (cG-PK). The site-directed anti-peptide antibody CNC2 was produced against the COOH-terminal end of the class C L-type alpha 1 subunit as predicted by molecular cloning and sequencing of cDNA. CNC2 recognized LC2 but not LC1 by immunoblotting and immunoprecipitated only LC2 phosphorylated by either cA-PK or PKC. These results indicate that LC1 is truncated at its COOH-terminal end with respect to LC2 and that cA-PK preferentially phosphorylates sites in the COOH-terminal region of the alpha 1 subunit that are present in LC2 but not LC1. The selectivity of cA-PK for phosphorylation of the COOH-terminal region of LC2 suggests that the channel activities of the two alpha 1 subunit size forms may be differentially regulated by neurotransmitters and hormones which act through cAMP-dependent mechanisms, while both alpha 1 subunit isoforms may be modulated by PKC, cG-PK, and calcium- and calmodulin-dependent protein kinase II.

Progesterone receptor messenger ribonucleic acid and protein are overexpressed in human uterine leiomyomas

OBJECTIVE

Our purpose was to identify molecular mechanisms underlying abnormal growth of uterine leiomyomas.

STUDY DESIGN

Biopsy samples of tumor and adjacent "normal" myometrium from nine patients were analyzed for progesterone receptor gene expression and for proliferation-associated antigen Ki-67.

RESULTS

Northern analysis indicated that progesterone receptor messenger ribonucleic acid levels were increased twofold to 15-fold in leiomyoma compared with adjacent myometrial biopsy tissue from all patients (n = 9), whereas beta-actin messenger ribonucleic acid was at similar levels in these samples. Quantitative immunoassay, immunohistochemistry studies, and Western blot analyses revealed increased amounts of progesterone receptor protein in the tumor tissue. Both the progesterone receptor A and B forms were expressed in the leiomyoma and adjacent myometrium. Corresponding to increased progesterone receptor gene expression, the proliferation-associated antigen Ki-67 was also significantly elevated in the leiomyoma tissue.

CONCLUSION

These data provide the first evidence that progesterone receptor messenger ribonucleic acid is overexpressed in uterine leiomyomas, suggesting that amplified progesterone-mediated signaling is instrumental in the abnormal growth of these tumors.

Analysis of complement C4 loci in Caucasoids and Japanese with idiopathic membranous nephropathy

Deletion of the HLA class III complement gene, C4A, has been linked with susceptibility to a number of autoimmune diseases. In this study, we show a strong positive association between C4A gene deletion and development of idiopathic membranous nephropathy (IMN) in European Caucasoids [patients, 17/27 (63%); healthy controls, 13/65 (20%); RR 6.8; P = 0.003]. To clarify whether C4A deletion is an independent risk factor for IMN or is increased secondarily to the Caucasoid HLA A1, B8, DR3 extended haplotype, we examined the frequency of C4A deletion in Japanese patients, in whom the disease is associated with another HLA haplotype (DR2-DQw1). Analysis of 31 Japanese patients and 46 healthy controls showed that C4A deletion was present in only one patient (3%) and one control (2%). In addition, examination of the C4B locus in Japanese patients showed that there was no significant increase in the estimated frequency of C4B deletion in patients against controls (31 vs. 27%) and no difference in the frequency of the C4B long gene (73 vs. 87%) or C4B short gene (77 vs. 78%). We conclude that although C4A deletion confers significant risk of IMN in Caucasoids, there is no significant association between C4 polymorphism, as detected here, and risk of IMN in Japanese. This suggests that either C4A deletion is irrelevant to the pathogenesis of IMN or that more than one genetic mechanism is involved.

Molecular mapping of the HLA class II region in HLA-DR3 associated idiopathic membranous nephropathy

Susceptibility to IMN is associated, in European Caucasoids, with the extended HLA haplotype in A1, B8, and DR3. It is unclear from previous investigations of HLA class II genes whether the association with A1, B8, DR3 is due to an HLA-DR or -DQ locus, or both, or to another locus linked to HLA class II. To examine genetic polymorphism over a more extensive area of DNA than previously, we carried out long range mapping of the HLA class II region of A1, B8, DR3 patients and healthy controls to discover if new markers of disease could be identified at this level of organization. Large fragments of genomic DNA were cut using enzymes with infrequent restriction sites, and were separated by pulsed field gel electrophoresis (PFGE) and analyzed using a series of probes which cover the HLA class II region. In several different DR3 haplotypes examined, the overall content of DNA and organization of the class II region were similar. However, both patient and control B8, DR3 haplotypes contained an extra Pvul site in the DRB region, compared to the disease-neutral B18, DR3 haplotype. Further, the DP region of the patient B8, DR3 haplotypes contained an additional partial BssHII cutting site which was not identified in the control B8, DR3 haplotypes. This structural heterogeneity in the vicinity of DP could have implications for genetic susceptibility to IMN and for linkage disequilibrium.

Biochemical properties and subcellular distribution of an N-type calcium channel alpha 1 subunit

A site-directed anti-peptide antibody, CNB-1, that recognizes the alpha 1 subunit of rat brain class B calcium channels (rbB) immunoprecipitated 43% of the N-type calcium channels labeled by [125I]omega-conotoxin. CNB-1 recognized proteins of 240 and 210 kd, suggesting the presence of two size forms of this alpha 1 subunit. Calcium channels recognized by CNB-1 were localized predominantly in dendrites; both dendritic shafts and punctate synaptic structures upon the dendrites were labeled. The large terminals of the mossy fibers of the dentate gyrus granule neurons were heavily labeled, suggesting that the punctate labeling pattern represents calcium channels in nerve terminals. The pattern of immunostaining was cell specific. The cell bodies of some pyramidal cells in layers II, III, and V of the dorsal cortex, Purkinje cells, and scattered cell bodies elsewhere in the brain were also labeled at a low level. The results define complementary distributions of N- and L-type calcium channels in dendrites, nerve terminals, and cell bodies of most central neurons and support distinct functional roles in calcium-dependent electrical activity, intracellular calcium regulation, and neurotransmitter release for these two channel types.

Localization of receptor sites for insect-selective toxins on sodium channels by site-directed antibodies

Site-directed antibodies corresponding to conserved putative extracellular segments of sodium channels, coupled with binding studies of radiolabeled insect-selective scorpion neurotoxins, were employed to clarify the relationship between the toxins' receptor sites and the insect sodium channel. (1) The depressant insect toxin LqhIT2 was shown to possess two noninteracting binding sites in locust neuronal membranes: a high-affinity (KD1 = 0.9 +/- 0.6 nM) and low-capacity (Bmax1 = 0.1 +/- 0.07 pmol/mg) binding site as well as a low-affinity (KD2 = 185 +/- 13 nM) and high-capacity (Bmax2 = 10.0 +/- 0.6 pmol/mg) binding site. (2) The high-affinity site serves as a target for binding competition by the excitatory insect toxin AaIT. (3) The binding of LqhIT2 was significantly inhibited in a dose-dependent manner by each of four site-directed antibodies. The binding inhibition resulted from reduction in the number of binding sites. (4) The antibody-mediated inhibition of [125I]AaIT binding differs from that of LqhIT2: three out of the four antibodies which inhibited LqhIT2 binding only partially affected AaIT binding. Two antibodies, one corresponding to extracellular and one to intracellular segments of the channel, did not affect the binding of either toxin. These data suggest that the receptors to the depressant and excitatory insect toxins (a) comprise an integral part of the insect sodium channel, (b) are formed by segments of external loops in domains I, III, and IV of the sodium channel, and (c) are localized in close proximity but are not identical in spite of the competitive interaction between these toxins.

Characterization of the two size forms of the alpha 1 subunit of skeletal muscle L-type calcium channels

The molecular properties of two size forms of the alpha 1 subunit of purified skeletal muscle calcium channels were analyzed. The minor, full-length, form, alpha 1(212), was found to have an apparent molecular mass of 214 kDa by Ferguson plot analysis, while the major, truncated, form, now designated alpha 1(190), had an apparent molecular mass of 193 kDa. Antibody mapping of the C-terminal region of alpha 1(190) with 10 anti-peptide antibodies placed the C terminus between residues 1685 and 1699. Three consensus sites for cAMP-dependent protein phosphorylation are present in the C-terminal region of alpha 1(212) but not in alpha 1(190), and they may be important for the regulation of the ion conductance activity of the calcium channel.

Subunits of purified calcium channels. Alpha 2 and delta are encoded by the same gene

Polyacrylamide gel electrophoresis of purified rabbit skeletal muscle L-type calcium channel before and after reduction of disulfide bonds confirmed that 27- and 24-kDa forms of the delta subunit are disulfide-linked to the 143-kDa alpha 2 subunit. The amino acid sequences of three peptides obtained by tryptic digestion of the delta subunits corresponded to amino acid sequences predicted from the 3' region of the mRNA encoding alpha 2. One of these peptides had the same sequence as the N terminus of the 24- and 27-kDa forms of the delta subunit and corresponded to residues 935-946 of the predicted alpha 2 primary sequence. Anti-peptide antibodies directed to regions on the N-terminal side of this site recognized the 143-kDa alpha 2 subunit in immunoblots of purified calcium channels under reducing conditions, whereas an antipeptide antibody directed toward a sequence on the C-terminal side of this site recognized 24- and 27-kDa forms of the delta subunit. A similar result was obtained after immunoblotting using purified transverse tubules or crude microsomal membrane preparations indicating that alpha 2 and delta occur as distinct disulfide-linked polypeptides in skeletal muscle membranes. Thus, the delta subunits are encoded by the same gene as the alpha 2 subunit and are integral components of the skeletal muscle calcium channel.

Influence of single and multiple doses of oral ranitidine on the gastric transit of an indigestible capsule in humans

The effect of single and multiple doses of ranitidine on the gastric residence time of an indigestible pH-sensitive radiotelemetric device, the Heidelberg capsule, was evaluated in 12 healthy men (mean age, 29 +/- 8 years) in a placebo-controlled, randomized, crossover study. Each subject received 150 mg ranitidine or placebo orally 2 hours before administration of the Heidelberg capsule. A 500 kcal standardized breakfast was served 1/2 hour before the capsule was administered. Gastric pH was monitored at 15-minute intervals, until pyloric passage (pH increase greater than or equal to 3 U) of the Heidelberg capsule was observed. Blood samples (n = 12) were collected 0 to 8 hours after administration of drug or placebo. The subjects continued to receive ranitidine or placebo b.i.d. for 7 days and returned on day 8 for a similar evaluation. After a 1-week washout period, the subjects received the alternative treatment. The mean (+/- SD) gastric residence time of the Heidelberg capsule was significantly decreased after both single and multiple doses of ranitidine compared to placebo (3.1 +/- 0.9 versus 3.8 +/- 1.1 hours, p less than 0.02; and 2.9 +/- 0.74 versus 3.9 +/- 0.9 hours, p less than 0.005, n = 9). Gastric residence time was not determined in three subjects who showed unusually slow gastrointestinal motility after both placebo and ranitidine. Mean AUC(0-8 hr) and AUC(0-infinity) were significantly increased, whereas Cmax, tmax, and t1/2 remained unchanged after 7 days of ranitidine b.i.d. treatment. No ranitidine double-peak profile or linear pharmacokinetic-pharmacodynamic relationship was identified.(ABSTRACT TRUNCATED AT 250 WORDS)

Skin preparation in the surgical patient

A historical review of skin antisepsis is given. Current practices, rationales for skin antisepsis as a segment of total wound care, and bacteriological factors are discussed. The results of a telephone survey of current practices of 16 medical centers around the country are presented. Discussion and conclusions relative to survey results and skin care agents are given. Characteristics of an ideal skin preparation yet to be obtained and some common myths relating to this subject are discussed.

Can acute cholecystitis produce obstructive jaundice in the absence of choledocholithiasis?

A case is presented of acute cholecystitis that produced extensive ascending, intrahepatic acute cholangitis (sufficient to produce obstructive jaundice of significant degree) without evidence of choledocholithiasis or ductal dilatation.Questions are raised concerning the present accepted clinical classification of both cholangitis and obstructive jaundice.