New colorimetric cytotoxicity assay for anticancer-drug screening

We have developed a rapid, sensitive, and inexpensive method for measuring the cellular protein content of adherent and suspension cultures in 96-well microtiter plates. The method is suitable for ordinary laboratory purposes and for very large-scale applications, such as the National Cancer Institute's disease-oriented in vitro anticancer-drug discovery screen, which requires the use of several million culture wells per year. Cultures fixed with trichloroacetic acid were stained for 30 minutes with 0.4% (wt/vol) sulforhodamine B (SRB) dissolved in 1% acetic acid. Unbound dye was removed by four washes with 1% acetic acid, and protein-bound dye was extracted with 10 mM unbuffered Tris base [tris (hydroxymethyl)aminomethane] for determination of optical density in a computer-interfaced, 96-well microtiter plate reader. The SRB assay results were linear with the number of cells and with values for cellular protein measured by both the Lowry and Bradford assays at densities ranging from sparse subconfluence to multilayered supraconfluence. The signal-to-noise ratio at 564 nm was approximately 1.5 with 1,000 cells per well. The sensitivity of the SRB assay compared favorably with sensitivities of several fluorescence assays and was superior to those of both the Lowry and Bradford assays and to those of 20 other visible dyes. The SRB assay provides a colorimetric end point that is nondestructive, indefinitely stable, and visible to the naked eye. It provides a sensitive measure of drug-induced cytotoxicity, is useful in quantitating clonogenicity, and is well suited to high-volume, automated drug screening. SRB fluoresces strongly with laser excitation at 488 nm and can be measured quantitatively at the single-cell level by static fluorescence cytometry.

Influence of condition of surgical margins on local recurrence and disease-specific survival in oral and oropharyngeal cancer

BACKGROUND

The clearance of surgical margins at the primary site is widely thought to influence the subsequent course of the disease in patients operated on for oral and oropharyngeal carcinoma. In some reports the adverse impact of close or involved margins was not negated by postoperative radiotherapy. These findings, in addition to descriptive histopathological studies, have led some authors to recommend margins of more than a macroscopic clearance of 1cm at certain subsites. We have therefore examined the relation between the condition of surgical margins and local recurrence and disease-specific survival.

METHODS

Identical treatment protocols were used to treat two independent groups of patients (Sydney, Australia, n=237; Lanarkshire, n=95) who presented with previously untreated carcinoma of the mouth or oropharynx. All patients were operated on with the primary objective of achieving a macroscopic clearance of 1cm. Postoperative radiotherapy was used according to a protocol. Data about patients were entered into comprehensive computerised databases prospectively. Known clinical and pathological prognostic indicators, in addition to the condition of surgical margins, were analysed to find out if they were predictive of local recurrence and disease-specific survival using the Cox proportional hazard model.

RESULTS

Local recurrence was predicted by the presence of perineural invasion at the primary site in both groups. Disease-specific survival was predicted by the presence and extent of regional lymph node metastases in both groups. The condition of surgical margins (clear, close, or involved) did not predict local recurrence, or disease-specific survival on multivariate analysis.

CONCLUSIONS

A macroscopic margin of 1cm seems adequate in the surgical management of oral and oropharyngeal carcinoma. For most patients who have close or involved margins the biology of the disease influences the subsequent course irrespective of the width of clearance of tumour.

The human myelin basic protein gene is included within a 179-kilobase transcription unit: expression in the immune and central nervous systems

Two human Golli (for gene expressed in the oligodendrocyte lineage)-MBP (for myelin basic protein) cDNAs have been isolated from a human oligodendroglioma cell line. Analysis of these cDNAs has enabled us to determine the entire structure of the human Golli-MBP gene. The Golli-MBP gene, which encompasses the MBP transcription unit, is approximately 179 kb in length and consists of 10 exons, seven of which constitute the MBP gene. The human Golli-MBP gene contains two transcription start sites, each of which gives rise to a family of alternatively spliced transcripts. At least two Golli-MBP transcripts, containing the first three exons of the gene and one or more MBP exons, are produced from the first transcription start site. The second family of transcripts contains only MBP exons and produces the well-known MBPs. In humans, RNA blot analysis revealed that Golli-MBP transcripts were expressed in fetal thymus, spleen, and human B-cell and macrophage cell lines, as well as in fetal spinal cord. These findings clearly link the expression of exons encoding the autoimmunogen/encephalitogen MBP in the central nervous system to cells and tissues of the immune system through normal expression of the Golli-MBP gene. They also establish that this genetic locus, which includes the MBP gene, is conserved among species, providing further evidence that the MBP transcription unit is an integral part of the Golli transcription unit and suggest that this structural arrangement is important for the genetic function and/or regulation of these genes.

Molecular and phenotypic mapping of the short arm of chromosome 5: sublocalization of the critical region for the cri-du-chat syndrome

Forty-nine individuals have been identified with deletions or translocations involving the short arm of chromosome 5. While most display the classical phenotype of the cri-du-chat syndrome, several of the patients do not have the syndrome or have only a subset of the clinical features. Somatic cell hybrids containing the deleted chromosome 5 were derived from each patient. Each somatic cell hybrid was analyzed at the DNA level using 136 chromosome 5p-specific DNA fragments. It was possible to unambiguously order most of the chromosomal breakpoints present in the somatic cell hybrids based on the hybridization patterns of Southern blots. Further comparisons between the deletions present in the patients and their clinical features identified several chromosomal regions that were involved in specific clinical features. A critical chromosomal region involved the high-pitched cry mapped to 5p15.3, while the chromosomal region involved in the remaining features of the cri-du-chat syndrome mapped to a small region within 5p15.2. Deletions that did not include these two chromosomal regions presented varying clinical phenotypes from severe mental retardation and microcephaly to a clinically normal phenotype. These results demonstrate the need for careful characterization of a 5p deletion in prenatal cases before clinical predictions are made.

FGF is an essential regulator of the fifth cell division in preimplantation mouse embryos

Fibroblast growth factor (FGF) signaling is required prior to gastrulation in the mouse embryo. To test for the spatial and temporal requirements of FGF signaling, a dominant negative FGF receptor (dnFGFR) was used to make transgenic mouse embryos. In mosaic embryos, cell division ceased at the fifth cell division in all cells that expressed the mutant receptor, but cell death did not increase. After the fifth cell division, the progeny of unaltered cells and cells expressing lacZ continued to accumulate at the same rate, suggesting that the FGF requirement is cell autonomous. In mosaic embryos, lacZ, but not dnFGFR expression was detected in mitotic trophoblasts adjacent to the ICM. Conversely, dnFGFR-expressing extraembryonic ectoderm cells were detected at the abembryonic pole in postmitotic cells. In blastocysts expressing the dnFGFR in all cells, the morphology appeared normal and inner cell masses (ICMs) formed, but resultant embryos had only one-third the number of cells as control embryos. In these blastocysts, cell division had also ceased at the fifth cell division, but cavitation, a concurrent morphogenetic event, initiated and progressed normally. To test for the continuing requirement of FGF, FGFR-3 was overexpressed in all cells and resulted in an increase in cell numbers after the fifth cell cycle. In a model for postimplantation development, addition of FGF-4 to blastocyst outgrowths increased the number of extraembryonic ectoderm cells, suggesting a continuing role for FGF. Thus, FGF signaling induces the cell division of embryonic and extraembryonic cells in the preimplantation mouse embryo starting at the fifth cell division. The signal requirement for FGF is cell autonomous, but is not required to prevent cell death. This provides the first evidence for the necessity of a growth factor before implantation.

Do nodal metastases from cutaneous melanoma of the head and neck follow a clinically predictable pattern?

BACKGROUND

Potential lymphatic drainage patterns from cutaneous melanomas of the head and neck are said to be variable and frequently unpredictable. The aim of this article is to correlate the anatomic distribution of pathologically involved lymph nodes with primary melanoma sites and to compare these findings with clinically predicted patterns of metastatic spread.

METHODS

A prospectively documented series of 169 patients with pathologically proven metastatic melanoma was reviewed by analyzing the clinical, operative, and pathologic records. Clinically, it was predicted that melanomas of the anterior scalp, forehead, and face could metastasize to the parotid and neck levels I-III; the coronal scalp, ear, and neck to the parotid and levels I-V; the posterior scalp to occipital nodes and levels II-V; and the lower neck to levels III-V. Minimum follow up was 2 years.

RESULTS

There were 141 therapeutic (97 comprehensive, 44 selective) and 28 elective lymphadenectomies (4 comprehensive dissections, 21 selective neck dissections, and 3 cases in which parotidectomy alone was performed). Overall, there were 112 parotidectomies, 44 of which were therapeutic and 68 elective. Pathologically positive nodes involved clinically predicted nodal groups in 156 of 169 cases (92.3%). The incidence of postauricular node involvement was only 1.5% (3 cases). No patient was initially seen with contralateral metastatic disease; however, 5 patients (2.9%) failed in the contralateral neck after therapeutic dissection. In 68% of patients, metastatic disease involved the nearest nodal group, and in 59% only a single node was involved.

CONCLUSIONS

Cutaneous malignant melanomas of the head and neck metastasized to clinically predicted nodal groups in 92% of patients in this series. Postauricular and contralateral metastatic node involvement was uncommon.

Antimicrobial resistance in enterococci isolated from Turkey flocks fed virginiamycin

From 125 separate cloacal cultures from three turkey flocks fed virginiamycin, 104 Enterococcus faecium and 186 Enterococcus faecalis isolates were obtained. As the turkeys aged, there was a higher percentage of quinupristin-dalfopristin-resistant E. faecium isolates, with isolates from the oldest flock being 100% resistant. There were no vancomycin-resistant enterococci. Results of pulsed-field gel electrophoresis (PFGE) indicated there were 11 PFGE types of E. faecalis and 7 PFGE types of E. faecium that were in more than one group of flock cultures.

Hepatitis C among noninjecting drug users: a report

OBJECTIVES

This report documents the prevalence of hepatitis C virus (HCV) infection among self-reported noninjecting drug users recruited from two New York City neighborhoods.

METHODS

Participants were recruited in separate studies from East Harlem and the Lower East Side of Manhattan and were administered structured questionnaires and tested for HCV.

RESULTS

HCV prevalence rates among those reporting no history of injecting drugs ranged from 5% to 29%, according to age, gender, and study location.

CONCLUSIONS

Our results suggest that more research is needed to elucidate potential noninjecting routes of HCV transmission among drug users. Moreover, policies that rely predominantly on injector status as the only drug-related risk factor for HCV screening need to be reassessed in light of these findings.

The significance of measles virus antigen and genome distribution in the CNS in SSPE for mechanisms of viral spread and demyelination

The distribution of measles virus (MV) antigen and genomic RNA in the central nervous system (CNS) in 10 cases of subacute sclerosing panencephalitis (SSPE) was determined using optimized immunocytochemistry and in situ hybridization techniques. As in previous reports neurons and oligodendrocytes were found to be the most frequently infected cells. It was confirmed that MV infection in neuronal processes was predominantly dendritic but there was also some evidence suggestive of occasional axonal involvement, a finding confirmed by electron microscopy. In addition MV genomic RNA was detected in neuronal processes, in some cases in the absence of demonstrable MV antigen. The relationship between myelin destruction and oligodendrocytic infection suggested that the demyelination may be solely the result of virus infection. A possible correlation between viral distribution and form and the clinical duration of disease was examined. Viral antigen and genome were equally abundant in the cerebral cortex in most short duration cases (<6 months). However, in two of these cases viral RNA but not antigen was detected in the spinal cord. In long duration cases (>36 months) viral RNA was abundant in all areas of the CNS examined, frequently in the absence of demonstrable antigen. These findings may suggest viral spread in a cephalo-caudal direction, probably by transneuronal spread.

Evaluation of clinical practice guidelines on outcome of infection in patients in the surgical intensive care unit

OBJECTIVE

In this study, clinical practice guidelines were developed by a multidisciplinary team for patients with infections admitted to a surgical intensive care unit (ICU).

DESIGN

A 51-day baseline audit period (Phase I) in a 20-bed (private rooms) surgical ICU was compared with a 34-day period in the same unit after implementation of the guidelines (Phase II).

PATIENTS

Phase I included 182 patients (670 patient days), and Phase II included 139 patients (427 patient days).

RESULTS

There was no significant difference between patients in the Phase I and Phase II groups regarding age (65.4/19-95 vs. 64.8/18-90 yrs), gender (56% male vs. 55% male), severity of illness (mean Acute Physiology and Chronic Health Evaluation III, 38 vs. 39.1), total infections (respiratory, 8% vs. 4%; urinary tract, 15% vs. 4%; wound, 4% vs. 3%; skin/soft tissue, 3% vs. 7%; sepsis, 5% vs. 3%; intra-abdominal, 9% vs. 17%), and no infection (64% vs. 67%). Clinical outcomes of patients with infections in the Phase I group compared with those in the Phase II group were as follows: clinical improvement or cure, 64% vs. 76%; persistent infection, 17% vs. 11%; clinical failure, 0 vs. 2%; and death, 18% vs. 7% (p = NS). When patients with infections were compared, death rates were 20% in the Phase I group and 5.6% in the Phase II group (p = .02). After implementation of the clinical pathways, antibiotic costs were reduced from $676.54 per patient to $157.88 per patient (p = .001). Length of stay in the ICU was 3.7 days in the Phase I trial and a mean of 3 days in the Phase II trial (p = NS). Specimens of Escherichia coli demonstrated a trend toward a decreased resistance to all antibiotics and Pseudomonas aeruginosa to ciprofloxacin and aminoglycosides (p = NS).

CONCLUSIONS

In this study, the use of clinical practice guidelines for patients who were admitted to the surgical ICU was shown to reduce costs, without adversely affecting patients' outcomes. This study has important implications for the use of clinical practice guidelines for the management of patients with infections who are admitted to surgical ICUs.

Extreme altitude mountaineering and Type 1 diabetes; the Diabetes Federation of Ireland Kilimanjaro Expedition

AIMS

To examine the effects of extreme altitude mountaineering on glycaemic control in Type 1 diabetes, and to establish whether diabetes predisposes to acute mountain sickness (AMS).

METHODS

Fifteen people with Type 1 diabetes and 22 nondiabetic controls were studied during the Diabetes Federation of Ireland Expedition to Kilimanjaro. Daily insulin requirements, blood glucose estimations and hypoglycaemic attacks were recorded in diaries by the people with diabetes. The performance of blood glucose meters at altitude was assessed using standard glucose solutions. Symptoms of acute mountain sickness were recorded daily by people with diabetes and by the nondiabetic controls using the Lake Louise Scoring Charts. The expedition medical team recorded the incidence of complications of altitude and of diabetes. The final height attained for each individual was recorded by the expedition medical team and verified by the expedition guides.

RESULTS

The final altitude ascended was lower in the diabetic than the nondiabetic group (5187 +/- 514 vs. 5654 +/- 307 m, P = 0.001). The mean daily insulin dose was reduced from 67.1 +/- 28.3-32.9 +/- 11.8 units (P < 0.001), but only 50% of recorded blood glucose readings were within the target range of 6-14 mmol/L. There were few hypoglycaemic attacks after the first two days of climbing. Both blood glucose meters tested showed readings as low as 60% of standard glucose concentrations at high altitude and low temperatures. The Lake Louise questionnaires showed that symptoms of AMS occurred equally in the diabetic and nondiabetic groups. There were two episodes of mild diabetic ketoacidosis; two of the diabetic group and three of the nondiabetic group developed retinal haemorrhages.

CONCLUSIONS

People with Type 1 diabetes can participate in extreme altitude mountaineering. However, there are significant risks associated with this activity, including hypoglycaemia, ketoacidosis and retinal haemorrhage, with the additional difficulties in assessing glycaemic control due to meter inaccuracy at high altitude. People with Type 1 diabetes must be carefully counselled before attempting extreme altitude mountaineering.

Complications of meningococcal disease in college students

A retrospective study was conducted to provide a description of the risk, complications, fatality, and sequelae associated with invasive meningococcal disease in college students admitted in the Allegheny county (Pennsylvania) hospital system from January 1990 to May 1999.

Experiences of care by Australians with a diagnosis of borderline personality disorder

Borderline personality disorder (BPD) is a complex and challenging mental health condition for the person and service providers who support them. This paper reports on the results of a survey of 153 people with a diagnosis of BPD about their experiences of attempting to receive support in managing this mental health condition. It provides their perceptions of a range of experiences not reported in the existing literature, including general practitioner roles, urban and rural differences, public and private hospital differences, and comparison of usefulness of support across multiple support types. People with a diagnosis of BPD continue to experience significant discrimination when attempting to get their needs met within both public and private health services. Further education for nurses and other health professionals is indicated to address pervasive negative attitudes towards people with a diagnosis of BPD. There is limited understanding of the experience of seeking and receiving treatment and care by people with a diagnosis of borderline personality disorder (BPD), their perceptions of barriers to care and the quality of services they receive. This study aimed to explore these experiences from the perspective of Australians with this diagnosis. An invitation to participate in an online survey was distributed across multiple consumer and carer organizations and mental health services, by the Private Mental Health Consumer Carer Network (Australia) in 2011. Responses from 153 people with a diagnosis of BPD showed that they experience significant challenges and discrimination when attempting to get their needs met within both public and private health services, including general practice. Seeking help from hospital emergency departments during crises was particularly challenging. Metropolitan and rural differences, and gender differences, were also apparent. Community supports were perceived as inadequate to meet their needs. This study provides data on a range of experiences not reported in existing literature, including general practitioner roles, urban and rural differences, public and private hospital differences, and comparison of usefulness of support across multiple support types. Its findings can help inform better training for health professionals and better care for this population.

Negative alcohol expectancy predicts post-treatment abstinence survivorship: the whether, when and why of relapse to a first drink

Using survival analysis, the association was explored between positive and negative alcohol expectancies measured on admission to a non-residential alcohol dependence treatment unit and post-treatment relapse to a first drink (first slip). A reliable association between negative alcohol expectancy (but not positive) and relapse was found. The active negative alcohol expectancies were distal rather than proximal: proximal expectancies surround consumption ('same day' expectancies) and distal expectancies relate to the 'next-day' following consumption or those longer term expectancies coming from 'continued drinking'. Only the 'next day' component of distal expectancies formed a reliable association with relapse. The use to which negative alcohol expectancy as measured by the Negative Alcohol Expectancy Questionnaire might be put is discussed in terms of (i) a bottom-up representation of motivation for recovery to help treatment match and (ii) a provisor of detailed, client-specific information for structuring motivational interventions.

High-efficiency plasmid gene transfer into dystrophic muscle

The efficiency of plasmid gene transfer in skeletal muscle is significantly enhanced by pretreatment with hyaluronidase and the application of an electrical field to the muscle following the injection of plasmid DNA, a process referred to as electrotransfer. However, the presence of increased levels of connective tissue in muscular dystrophies, such as Duchenne muscular dystrophy (DMD), may affect the efficiency of this process. Here we demonstrate that the efficiency of electrotransfer is not affected by increased levels of connective tissue in the mdx mouse model of DMD and that any damage induced by the electrotransfer process is not exacerbated in the dystrophic phenotype. However, increasing the concentration of hyaluronidase does not improve transfection efficiencies further. Unlike direct injection of plasmid DNA, the efficiency of electrotransfer is not dependent upon the sex and age of mice used. The combined treatment of hyaluronidase and electrotransfer results in highly efficient gene transfer in dystrophic muscle with limited muscle damage.