Assessing the mechanism and therapeutic potential of modulators of the human Mediator complex-associated protein kinases

Mediator-associated kinases CDK8/19 are context-dependent drivers or suppressors of tumorigenesis. Their inhibition is predicted to have pleiotropic effects, but it is unclear whether this will impact on the clinical utility of CDK8/19 inhibitors. We discovered two series of potent chemical probes with high selectivity for CDK8/19. Despite pharmacodynamic evidence for robust on-target activity, the compounds exhibited modest, though significant, efficacy against human tumor lines and patient-derived xenografts. Altered gene expression was consistent with CDK8/19 inhibition, including profiles associated with super-enhancers, immune and inflammatory responses and stem cell function. In a mouse model expressing oncogenic beta-catenin, treatment shifted cells within hyperplastic intestinal crypts from a stem cell to a transit amplifying phenotype. In two species, neither probe was tolerated at therapeutically-relevant exposures. The complex nature of the toxicity observed with two structurally-differentiated chemical series is consistent with on-target effects posing significant challenges to the clinical development of CDK8/19 inhibitors.

Abstract P6-10-17: Rates of prophylactic surgeries among BRCA 1 or 2 mutation carriers: A single institution experience

Background

Women with identified BRCA1/2 mutation have a substantially increased risk of developing several types of cancer, mainly breast and ovarian, during their lifetime. Management options included close surveillance, chemoprevention and prophylactic surgeries. The aim of this study is to assess the rate of prophylactic surgeries among BRCA1/2 carriers counseled and screened at a single institution in the last 2 decades.

Methods

We retrospectively captured all women with a BRCA1/2 mutation that were identified in our genetic clinic between 2000 and 2015. The incidence of breast and ovarian cancer among all BRCA carriers was reported. The rates of prophylactic surgeries were calculated and analyzed in all identified carriers.

Results

Six hundred and eighty four women were identified to carry a deleterious BRCA mutation, among them 364 BRCA1 (53%) and 320 BRCA2 (47%). Three hundred and twenty seven (48%) were diagnosed with breast cancer and 80 (12%) had either ovarian or fallopian tumor. Forty percent (N=271) of the women assessed were healthy carriers. Prophylactic bilateral salpingo-oophorectomies (BSO) were performed in 342 women (50%) and prophylactic mastectomies (PM) (bilateral or unilateral) in 190 (28%). Furthermore, 154 women (23%) had both BSO and PM. Of note, 79 women (12%) were less than 35 years old and 122 were less than 40 years old (18%), the majority of those were waiting to have BSO later on. If we remove the young women from the analysis, 57 and 61% of the women would have had BSO (less than 35 and 40 years excluded respectively). If we only analyze the women who had a recent follow up in our clinic (2014-2015), 422 women would be eligible. Among those, 58 and 84 were less than 35 and 40 years old (y) respectively. For this cohort, the rates of BSO would be 61% (257/422)(whole cohort), 71% (excluding women less than 35y) and 76% (excluding women less than 40y).

Conclusion

A promising rate of BSO was reported in our cohort of BRCA carriers as compared to the literature. This rate was even higher (from 50 to over 70%) when we only analyzed patients with recent follow up in clinic and when we excluded young women waiting to have BSO. More efforts are needed to determine why the rates of PM are lower, for example limited breast reconstruction resources, in order to reduce the incidence of subsequent invasive breast cancer in this high-risk population.

Citation Format: Raphael J, Hewitt P, Graham T, Ott K, Mancuso T, Lorentz J, Emmerson M, Eisen A. Rates of prophylactic surgeries among BRCA 1 or 2 mutation carriers: A single institution experience. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P6-10-17.

An Exploratory Evaluation of the Utility of Transcriptional and Urinary Kidney Injury Biomarkers for the Prediction of Aristolochic Acid–Induced Renal Injury in Male Rats

The predictive value of different urinary and transcriptional biomarkers was evaluated in a proof-of-principle toxicology study in rats using aristolochic acid (AA), a known nephrotoxic agent. Male Wistar rats were orally dosed with 0.1, 1, or 10 mg/kg for 12 days. Urine was collected on days 1, 5, and 12 over 24 hours. Gene expression analysis was also conducted using quantitative real-time polymerase chain reaction and Illumina whole-genome chips. Protein biomarkers (Kim-1, Timp-1, vascular endothelial growth factor, osteopontin, clusterin, cystatin C, calbindin D-28K, β2-microglobulin, α–glutathione S-transferase, GSTY1b, RPA-1, and neutrophil gelatinase-associated lipocalin) were measured in these urine samples. Treatment with AA resulted in a slight dose- and/or time-dependent increase in urinary β2-microglobulin, lipocalin 2, and osteopontin before an increase in serum creatinine or serum urea nitrogen was observed. A strong decrease in urinary calbindin D-28K was also detected. The Compugen Ltd. prediction model scored both the 1- and 10-mg/kg AA dose groups as positive for nephrotoxicity despite the absence of renal histopathological changes. In addition, several previously described transcriptional biomarkers were identified as early predictors of renal toxicity as they were detected before morphological alterations had occurred. Altogether, these findings demonstrated the predictive values of renal biomarkers approved by the Food and Drug Administration, European Medicines Agency, and Pharmaceuticals & Medical Devices Agency in AA-induced renal injury in rats and confirmed the utility of renal transcriptional biomarkers for detecting progression of compound-induced renal injury in rats. In addition, several transcriptional biomarkers identified in this exploratory study could present early predictors of renal tubular epithelium injury in rats.

Development of a pharmaceutical hepatotoxicity biomarker panel using a discovery to targeted proteomics approach

There is a pressing and continued need for improved predictive power in preclinical pharmaceutical toxicology assessment as substantial numbers of drugs are still removed from the market, or from late-stage development, because of unanticipated issues of toxicity. In recent years a number of consortia have been formed with a view to integrating -omics molecular profiling strategies to increase the sensitivity and predictive power of preclinical toxicology evaluation. In this study we report on the LC-MS based proteomic analysis of the effects of the hepatotoxic compound EMD 335823 on liver from rats using an integrated discovery to targeted proteomics approach. This compound was one of a larger panel studied by a variety of molecular profiling techniques as part of the InnoMed PredTox Consortium. Label-free LC-MS analysis of hepatotoxicant EMD 335823 treated animals revealed only moderate correlation of individual protein expression with changes in mRNA expression observed by transcriptomic analysis of the same liver samples. Significantly however, analysis of the protein and transcript changes at the pathway level revealed they were in good agreement. This higher level analysis was also consistent with the previously suspected PPARα activity of the compound. Subsequently, a panel of potential biomarkers of liver toxicity was assembled from the label-free LC-MS proteomics discovery data, the previously acquired transcriptomics data and selected candidates identified from the literature. We developed and then deployed optimized selected reaction monitoring assays to undertake multiplexed measurement of 48 putative toxicity biomarkers in liver tissue. The development of the selected reaction monitoring assays was facilitated by the construction of a peptide MS/MS spectral library from pooled control and treated rat liver lysate using peptide fractionation by strong cation exchange and off-gel electrophoresis coupled to LC-MS/MS. After iterative optimization and quality control of the selected reaction monitoring assay panel, quantitative measurements of 48 putative biomarkers in the liver of EMD 335823 treated rats were carried out and this revealed that the panel is highly enriched for proteins modulated significantly on drug treatment/hepatotoxic insult. This proof-of-principle study provides a roadmap for future large scale pre-clinical toxicology biomarker verification studies whereby putative toxicity biomarkers assembled from multiple disparate sources can be evaluated at medium-high throughput by targeted MS.

Use of SELDI MS to discover and identify potential biomarkers of toxicity in InnoMed PredTox: a multi-site, multi-compound study

A serious bottleneck in the drug development pipeline is the inability of current pre-clinical toxicology evaluation methods to predict early on, and with good accuracy, that a drug candidate will have to be removed from development due to toxicology/safety issues. The InnoMed PredTox consortium attempted to address this issue by assessing the value of using molecular profiling techniques (proteomics, transcriptomics, and metabonomics), in combination with conventional toxicology measurements, on decision making earlier in pre-clinical safety evaluation. In this study, we report on the SELDI-TOF-MS proteomics component of the InnoMed PredTox project. In this large scale, multi-site, multi-compound study, tissue and plasma samples from 14-day in vivo rat experiments conducted for 16 hepato- and nephro-toxicants with known toxicology endpoints (including 14 proprietary compounds and 2 reference compounds) were analyzed by SELDI-TOF-MS. We have identified seven plasma proteins and four liver proteins which were shown to be modulated by treatment, and correlated with histopathological evaluations and can be considered potential biomarker candidates for the given toxicology endpoints. In addition, we report on the intra- and inter-site variations observed based on measurements from a reference sample, and steps that can be taken to minimize this variation.

Assessment of candidate biomarkers of drug-induced hepatobiliary injury in preclinical toxicity studies

This study was designed to assess the value of a set of potential markers for improved detection of liver injury in preclinical toxicity studies. Male Wistar rats were treated with drug candidates (BAY16, EMD335823, BI-3) that previously failed during development, in part due to hepatotoxicity, at two dose levels for 1, 3 and 14 days. Concentrations of lipocalin-2/NGAL and clusterin, which are frequently overexpressed and released from damaged tissues, and thiostatin, recently identified within PredTox as being elevated in urine in response to liver injury, were determined in rat urine and serum by ELISA. This was supplemented by confirmatory qRT-PCR and immunohistochemical analyses in the target organ. Serum paraoxonase-1 activity (PON1), which has been suggested as a marker of hepatotoxicity, was determined using a fluorometric assay. Clusterin and PON1 were not consistently altered in response to liver injury. In contrast, thiostatin and NGAL were increased in serum and urine of treated animals in a time- and dose-dependent manner. These changes correlated well with mRNA expression in the target organ and generally reflected the onset and degree of drug-induced liver injury. Receiver-operating characteristics (ROC) analyses supported serum thiostatin, but not NGAL, as a better indicator of drug-induced hepatobiliary injury than conventional clinical chemistry parameters, i.e. ALP, ALT and AST. Although thiostatin, an acute phase protein expressed in a range of tissues, may not be specific for liver injury, our results indicate that thiostatin may serve as a sensitive, minimally-invasive diagnostic marker of inflammation and tissue damage in preclinical safety assessment.

Phase I and II enzyme characterization of two sources of HepG2 cell lines

1: The metabolism by HepG2 cell from two sources (M1, M2) of 12 substrates is reported: ethoxyresorufin, ethoxycoumarin, testosterone, tolbutamide, chlorzoxazone, dextromethorphan, phenacetin, midazolam, acetaminophen, hydroxycoumarin, p-nitrophenol and 1-chloro-2,4-dinitrobenzene (CDNB), and a pharmaceutical compound, EMD68843. 2: Activities varied markedly. Some were present in M1 (CYP1A, CYP2C9, CYP2E1) but absent in M2. M1 had a more complete set of Phase I enzymes than M2. CYP1A2, CYP2C9, CYP2D6, CYP2E1 and CYP3A activities were present at levels similar to human hepatocytes. Phase II metabolism differed between M1 and M2. M1 conjugated hydroxycoumarin and p-nitrophenol to glucuronides only, whereas M2 produced sulfates. Glutathione conjugation of CDNB metabolism was 10-fold higher in M1 than in M2, but was still much lower than in human hepatocytes. CYP2E, CYP2C, CYP2B6 and CYP3A (but not CYP1A, glucuronyl S-transferase or S-transferase) were inducible in M1. Metabolites of EMD68843, produced by induced (but not uninduced) M1 were the same as those produced in human hepatocytes. 3: In conclusion, HepG2 cells have both Phase I and II enzymes, which activities and at what levels depend on the source and culture conditions. Therefore, HepG2 cells routinely used in in vitro assays should be characterized for their drug-metabolizing capabilities before any results can be fully interpreted.

Meta-analysis of randomized controlled trials as a method of estimating rare complications of non-steroidal anti-inflammatory drug therapy

The design of randomized controlled trials to assess the efficacy of pharmacological measures for the prevention of the gastrointestinal side-effects of anti-inflammatory drugs requires an accurate estimate of excess risk under controlled conditions. Photocopies of 952 randomized controlled trial publications were obtained after scanning titles and abstracts of a MEDLINE computer search, 427 were excluded for obvious reasons, and 525 were again photocopied after obliterating source and results. Selection criteria were: the presence of a non-anti-inflammatory drug control group; at least 4 days of therapy; at least 3 days without anti-inflammatory drugs before randomization; no complicating background drugs; mention of side-effects; and a clear differentiation of gastrointestinal complications. Observer error, with two independent readings, for inclusion suitability in the study was 19% for Methods and 9% for Results. For the 44 aspirin trials, the mean therapy duration was 357 days; the unweighted rate difference between therapy and control groups ( +/- 1 S.E.M.) for ulcer was 0.006 +/- 0.003, for gross haemorrhage 0.006 +/- 0.002 and for unspecified gastric symptoms 0.03 +/- 0.01. In 123 non-aspirin non-steroidal anti-inflammatory drug (NA-NSAID) trials, the mean duration was 67 days; the unweighted rate difference for ulcer was 0.0005 +/- 0.0003, for gross haemorrhage 0.007 +/- 0.004 and for unspecified gastric symptoms 0.02 +/- 0.005. Risk differences were also pooled using the DerSimonian and Laird method, which weights studies inversely according to variance. Using this method, only the unspecified gastric symptoms for non-aspirin non-steroidal anti-inflammatory drugs (NA-NSAIDs) and the haemorrhage for aspirin were found to be statistically significant. Longer studies have higher risk differences. Randomized control trials to determine prophylactic efficacy against haemorrhage (that is, to demonstrate a reduction of ulcer rate in the therapy group to the rate of controls) would require 190 patients in each group for NA-NSAIDs in studies of 2-6 months; 950 subjects would be needed to detect a 50% reduction. Randomized control trials to determine a reduction in ulcer rate to that of controls in patients on aspirin for more than 6 months would require 700 subjects in each group; 3346 subjects would be needed to detect a 50% reduction. Such studies are feasible.

vCJD and blood transfusion in the United Kingdom

A study was set up in the UK in 1997 to examine whether there is any evidence that variant Creutzfeldt-Jakob disease (vCJD) is transmitted by blood transfusion. To date, the study has identified three probable cases of vCJD transmission by blood transfusion, including two clinical cases and one pre- (or sub-) clinical case.

Evaluation of innovations in nursing practice: report and discussion

AIM

To assess whether a pilot study conducted in the UK achieved its objective to reduce admissions to hospital and bed days in patients identified as suitable recipients of case management by community matrons.

BACKGROUND

The Department of Health has advocated the use of nurse-led case management to improve the coordination of care and prevent inappropriate hospital admissions.

METHOD

66 patients and another 66 controls were identified for the 'Evercare' caseload according to criteria set by United Healthcare. Admissions data for the six months after entry into the study were collected from the hospital information system.

FINDINGS

admission rates in both the control and intervention group decreased over time and there was no significant difference in rates between the two groups at six months. There was no demonstrable effect on length of stay either. Users were satisfied with the service and nurses cited several clinical stories implying benefits for individual patients.

Transfusion-transmitted malaria: current donor selection guidelines are not sufficient

A case of transfusion-transmitted malaria was identified in a 50-year-old male patient with sickle cell disease. The donor was Ghanaian, but had migrated to the UK some years previously and had not left the UK for 8 years. The donor met all of the extant donor selection guidelines [1] and a donation was consequently collected. However, on subsequent investigation of the case, the donor was found to be parasitaemic and have high titre malarial antibodies. As a result of this case, changes to the United Kingdom donor selection guidelines have been proposed. These changes will prevent any such further transmissions.

Paclitaxel for anthracycline-resistant AIDS-related Kaposi's sarcoma: clinical and angiogenic correlations

BACKGROUND

Murine data indicate that angiogenesis is central to the aetiopathogenesis of Kaposi's sarcoma (KS). Therefore, we measured angiogenic cytokines and growth factors in patients with AIDS-related KS during treatment with both antiretrovirals and second-line paclitaxel chemotherapy. Cytokines measured included tumour necrosis factor-alpha (TNF-alpha), basic fibroblast growth factor (bFGF), vascular endothelial growth factor (VEGF) and the interleukins IL-2, -6 and -12.

PATIENTS AND METHODS

Enzyme-linked immunosorbent assays (ELISAs) were carried out to measure plasma cytokine levels in 17 patients with AIDS-related KS who had progressed within 6 months of receiving liposomal anthracyclines and were treated with paclitaxel 100 mg/m(2) every 2 weeks. Measurements were carried out before progression, at commencement and at the completion of paclitaxel.

RESULTS

The objective response rate to paclitaxel was 71% (95% confidence interval 60% to 81%). In 17 patients with AIDS-related KS, we observed eight partial responses and four complete responses. Patients with AIDS Clinical Trial Group stage T1 disease had higher plasma VEGF (P = 0.05) and lower plasma TNF-alpha levels (P = 0.05) than patients with earlier stage T0 KS. There were no correlations between plasma cytokines (bFGF, VEGF, TNF-alpha, and IL-2,-6 and -12) and the CD4 and CD8 cell counts or HIV-1 RNA viral load. Response to paclitaxel was associated with a fall in plasma IL-6 levels (P = 0.04) but no change in other cytokines. There were no significant changes in CD4, CD8, CD16/56, CD19 cell counts and HIV-1 viral loads during chemotherapy.

CONCLUSIONS

Angiogenic cytokines may correlate with KS disease extent but not with cellular immune function or HIV viraemia. Response to paclitaxel therapy correlates with a fall in plasma IL-6 levels and recent data indicate this may be a surrogate marker of KS-associated herpesvirus viral load. Overall, clinical response in KS correlates poorly with known angiogenic cytokines.

The contribution of transfusion to HCV infection in England

The English HCV lookback programme has identified some individuals with transfusion-transmitted HCV infection. The path from the collection of donations from HCV-infected donors to the identification of infected recipients was constructed. The probability of different outcomes at each branch was derived from data collected during this programme. This path of probabilities was then used to produce a complete estimate of the number of recipients infected by blood transfusions (dead and alive at the end of 1995) by re-entry of blood components that fell out of the lookback at various steps prior to recipient testing, and entry of components from HCV-infected donations that were never identified for lookback. Less than 14,000 recipients were estimated to have been infected with HCV during the decade prior to the start of donation testing. Over 60% of these were expected to have died by the end of 1995. Transfusion has infected a large group of individuals. However, this group constitutes a very small, and declining, proportion of all HCV infections in the population.

Effects of handling and storage of blood on the stability of hepatitis C virus RNA: implications for NAT testing in transfusion practice

BACKGROUND AND OBJECTIVES

To determine the stability of hepatitis C virus (HCV) RNA during transport and storage of blood samples from donors, prior to screening for HCV by nucleic acid amplification technology.

MATERIALS AND METHODS

Various blood and plasma sample types were stored for up to 120 h at different temperatures and the HCV RNA level was measured using an in house quantitative reverse transcription-polymerase chain reaction.

RESULTS

No decline in HCV RNA level was observed after 72 h of storage of whole blood at 4 degrees C in EDTA tubes (Greiner) and Plasma Preparation Tubes (PPT; Becton Dickinson), while insignificant declines of 0.2 log10 and 0. 25 log10 occurred at 25 degrees C after 72 h in the EDTA tubes and PPT tubes, respectively. When whole blood was stored with mixed anticoagulants CPDA-1 and EDTA for up to 120 h, no decline in HCV RNA level was observed at 4 degrees C and 25 degrees C, while a significant decline of 0.37 log10 occurred at 37 degrees C after 120 h. The temperature during transportation was investigated with a 12-hour period at 25 degrees C and 37 degrees C before storage at 4 degrees C for 108 h. Neither temperature resulted in any loss of HCV RNA in comparison with 120 h of storage at 4 degrees C.

CONCLUSION

Whole blood anticoagulated with EDTA or CPDA-1/EDTA may be stored at up to 25 degrees C (room temperature) for up to 5 days without any significant loss in plasma HCV RNA level.

Large-scale HCV RNA screening in first-time blood donors: the first step towards genomic screening of blood donations. HCV RNA Screening Study Group

BACKGROUND AND OBJECTIVES

Individual genomic screening for viruses in blood donations is becoming increasingly pressing as an alternative to pool testing to improve the safety of the blood supply.

MATERIALS AND METHODS

To determine the feasibility and, possibly, efficacy of genomic screening for hepatitis C virus (HCV) in the blood service setting, a representative population of first-time blood donors was screened individually with a semi-automated genomic amplification assay for HCV RNA. First-time blood donors in two blood centres in the United Kingdom were screened in parallel for anti-HCV and HCV RNA by RT-PCR.

RESULTS

8, 417 serum samples were screened. A 99.95% specificity was observed and one anti-HCV-positive, HCV-RNA-positive donation was found. No seronegative HCV-RNA-positive donations were detected.

CONCLUSIONS

These results are consistent with the low prevalence of HCV infection in blood donors from the London area and demonstrate the high level of performance of the individual genomic screening method used in this study. When fully automated, such a method would be a highly suitable candidate for routine, automated genomic screening of HCV and, subsequently, of other pathogenic blood-borne viruses.

Prospective investigation of transfusion transmitted infection in recipients of over 20 000 units of blood. TTI Study Group

OBJECTIVES

To follow up recipients of 20 000 units of blood to identify any transmissions of infections through blood transfusion.

DESIGN

Follow up study of recipients of transfusion.

SETTING

22 hospitals in north London.

PARTICIPANT

Adult patients who had recently been transfused.

MAIN OUTCOME MEASURES

Patients had further blood samples taken at 9 months that were tested for markers of hepatitis B and C and HIV and human T cell leukaemia/lymphoma virus type I or II (HTLV) infections. Recent infections were distinguished from pre-existing infections by comparison with blood samples taken before transfusion.

RESULTS

9220 patients were recruited, and 5579 recipients of 21 923 units of blood were followed up. No transfusion transmitted infections were identified. The incidence of transfusion transmitted infections was 0 in 21 043 units (95% confidence interval for risk 0 to 1 in 5706 recipients) for hepatitis B; 0 in 21 800 units (0 to 1 in 5911 recipients) for hepatitis C; 0 in 21 923 units (0 to 1 in 5944 recipients) for HIV; and 0 in 21 902 units (0 to 1 in 5939 recipients) for human T cell leukaemia/lymphoma virus. Three patients acquired hepatitis B during or after hospital admission but not through transfusion; 176 (3%) had pre-existing hepatitis B infection. Sixteen (0.29%) patients had hepatitis C, and five (0.09%) had human T cell leukaemia/lymphoma virus.

CONCLUSIONS

The current risk of transfusion transmitted infections in the United Kingdom is very small, though hospital acquired infections may arise from sources other than transfusion. A considerable proportion of patients have pre-existing infections.

Hepatitis C lookback programme: a single hospital experience

As part of the national Hepatitis C (HCV) Lookback Programme, HCV-infected donors donating blood after September 1991 were identified and the fate of their previous donations received at a single hospital were traced; 123 of 160 implicated blood components were traceable and transfused. Only 19 recipients were alive and traceable and were tested for HCV. Nine of the 14 recipients (64%) of HCV-positive donations and 2 of 5 recipients (40%) of HCV-indeterminate donations had evidence of HCV infection. Neither the number of donor exposures nor the type of component was predictive of recipient HCV status. Three recipients have chronic active hepatitis. The Hepatitis C Lookback Programme successfully identifies some but not all cases of transfusion-transmitted HCV. Transfusion records, particularly in the medical case notes, should be substantially improved. Many of the traced recipients are young, so that identification of HCV is of great importance.

Chronic anemia due to parvovirus B19 infection in a bone marrow transplant patient after platelet transfusion

BACKGROUND

Many reports document the transmission of human parvovirus B19 (B19) infection by clotting factor concentrates manufactured from large plasma pools. Transmission via other blood components originating from a single donor or a small number of donors, however, seems to occur only rarely. The study reported here identifies a B19 infection that was transmitted via a platelet donation.

CASE REPORT

A multiply transfused allogeneic bone marrow transplant patient developed chronic anemia due to persistent B19 infection. The anemia responded to therapy with intravenous immunoglobulin. It was postulated that a transfusion was the source of the B19 infection. Archived sera from 90 implicated blood donors were tested for B19 IgM and DNA by the use of dot-blot hybridization and a nested polymerase chain reaction with primers from the B19 nonstructural gene. B19 DNA from patient and donor sera were sequenced. One of the 90 blood donors (Donor A) was B19 IgM positive and had a high level of B19 DNA. The patient was viremic 3 days after transfusion of platelets from this donor, and the sequence of B19 DNA from the patient exactly matched that of B19 DNA from the donor. A second blood donor (Donor B) had a low level of B19 DNA but was IgM negative. The patient showed no evidence of B19 infection after the transfusion of red cells from Donor B, and the sequence of this donor's B19 DNA was different from that in the patient.

CONCLUSION

Blood Donor A with asymptomatic acute B19 infection was the source of B19 infection in the bone marrow transplant patient. Donor B with a low level of B19 DNA was not the source of infection.

Laparoscopic colectomy

BACKGROUND

Laparoscopic colectomy has developed with the explosion of technology that has followed laparoscopic cholecystectomy. Accumulation of skills in general laparoscopic surgery has made complex surgery, such as colectomy, feasible.

METHODS

Three hundred fifty-nine laparoscopic cases were prospectively studied. Data has been kept on benign and malignant cases, operative results, hospital stay, and morbidity. Special care has been taken to follow malignant cases, looking for recurrence of disease.

RESULTS

There were 359 cases (206 females, 153 male) average age 58.8 years (18-94), and 149 patients had malignancy. All types of resections were performed, including 151 anterior resections, 66 right hemicolectomies (RHC), 36 total colectomies, and 22 rectopexies. Operating times fell with experience-the last 20 cases of anterior resection took 150 min (110-240) and of RHC took 130 min (65-210). Twenty-six (7%) cases were converted to open surgery. Hospital stays for anterior resection lasted 5-7 days (2-33); in the last 20 cases the average stay was 4 days. Morbidity included seven leaks (2.7%), four strictures (1.2%), 12 wound infections (3.3%), and nine ileus (2.5%). There were six deaths within 30 days-sepsis, myocardial infarction, aspiration pneumonia, and disseminated liver metastases. One hundred forty-nine cancer cases have had ten recurrences: one pelvic recurrence, six liver metastases, two para-aortic nodal, and one case of disseminated disease. Average time of recurrence was 33 months (15-46 months).

CONCLUSIONS

Laparoscopy in the hands of experienced laparoscopic surgeons is a safe, efficient procedure. All types of procedures are possible. Early results in 149 malignancies are encouraging and recurrence rates are low. Prospective studies, now that skills are developed to a level comparable to that of open surgery, are now being performed to further assess laparoscopy's possible role in treating cancer.

Percutaneous absorption of nicotinic acid, phenol, benzoic acid and triclopyr butoxyethyl ester through rat and human skin in vitro: further validation of an in vitro model by comparison with in vivo data

The in vitro percutaneous absorption of three model compounds, nicotinic acid, phenol and benzoic acid, and the herbicide triclopyr butoxyethyl ester (triclopyr BEE) has been investigated in flow-through diffusion cells using skin from male Fischer 344 rats and humans. After the application of the four chemicals to the epidermal surface of unoccluded full-thickness rat skin, the absorption of each compound across the skin and into the receptor fluid at 72 hr reached 3.7 +/- 0.3, 5.7 +/- 0.6, 26.7 +/- 3.7 and 48.3 +/- 1.2% (mean +/- SD, n = 2-7) of the applied dose for triclopyr BEE, nicotinic acid, phenol and benzoic acid, respectively. After the application of the four chemicals to the epidermal surface of unoccluded full-thickness human skin, the absorption of each compound across the skin and into the receptor fluid at 72 hr was significantly (P < 0.05) less than through rat skin, reaching 0.7 +/- 0.1, 0.7 +/- 0.2, 18.8 +/- 1.3 and 37.8 +/- 6.9% (mean +/- SD, n = 2-7) of the applied dose for triclopyr BEE, nicotinic acid, phenol and benzoic acid, respectively. Occlusion of the skin surface with teflon caps often significantly (P < 0.05) enhanced the percutaneous absorption of the model compounds, although this effect was not uniform, varying with the compound under study and the skin (rat or human) used. When rat skin was occluded with teflon caps, the extent of absorption at 72 hr reached 8.6 +/- 0.8, 36.2 +/- 1.7 and 51.8 +/- 3.3% (mean +/- SD, n = 3-4) for nicotinic acid, phenol and benzoic acid, respectively. Corresponding values for human skin occluded with teflon caps were 3.3 +/- 1.6, 47.1 +/- 0.5 and 65.5 +/- 7.1% (mean +/- SD, n = 3-4). The experiments on the absorption of each model compound through rat and human skin were repeated and there was generally good agreement between the results from the two sets of experiments. The in vitro data reported compare favourably with data obtained by other workers using both in vitro and in vivo methodologies. The in vitro: in vivo correlation supports the use of the flow-through diffusion cell system as a model for the prediction of percutaneous absorption in vivo in the rat and in humans.

Genetic characterization of Legionella pneumophila serogroup 1 associated with respiratory disease in Australia

Techniques were developed for genetic characterization of Legionella pneumophila serogroup 1 by using restriction fragment length polymorphism analysis. Allozyme analysis provided an index of the discrimination achieved by restriction fragment length polymorphism. Isolates from human cases of legionellosis were examined by both methods, and their profiles were compared with reference strains of L. pneumophila serogroup 1 obtained from the American Type Culture Collection. Eighteen distinct clones were evident among the isolates examined. Both methods could be used to trace the source of an outbreak of legionellosis caused by L. pneumophila serogroup 1.

Efficacy and safety of quinidine therapy for maintenance of sinus rhythm after cardioversion. A meta-analysis of randomized control trials

Because individual studies evaluating the role of quinidine in the maintenance of sinus rhythm after cardioversion from chronic atrial fibrillation have involved relatively few patients, a meta-analysis of randomized control trials was performed. Six trials published between 1970 and 1984 were selected by two blinded reviewers based on study design and statistical analysis. Data from these six trials involving 808 patients were pooled after testing for homogeneity of treatment effects across trials. Life table estimates of the percent of patients still in sinus rhythm at 3, 6, and 12 months after cardioversion were constructed for quinidine and control groups. The proportion of patients remaining in sinus rhythm in the quinidine group was 69%, 58%, and 50% at 3, 6, and 12 months postcardioversion respectively. The proportion of patients remaining in sinus rhythm in the control group was 45%, 33%, and 25% at the same time intervals. The pooled rate difference, or difference in proportion of patients in sinus rhythm between quinidine and control groups, was 24%, 23%, and 24% at 3, 6, and 12 months of follow-up (p less than 0.001 at all time intervals). The unadjusted total mortality rate in the quinidine-treated patients was 2.9% and in the control group was 0.8%. The odds of dying in the quinidine-treated group were approximately three times that of the control group ("typical" odds ratio = 2.98, p less than 0.05). Thus, quinidine treatment is more effective than no antiarrhythmic therapy in suppressing recurrences of atrial fibrillation but appears to be associated with increased total mortality.