Fertility control as a means of controlling bovine tuberculosis in badger (Meles meles) populations in south-west England: predictions from a spatial stochastic simulation model

A spatial stochastic simulation model was used to assess the potential of fertility control, based on a yet-to-be-developed oral bait-delivered contraceptive directed at females, for the control of bovine tuberculosis in badger populations in south-west England. The contraceptive had a lifelong effect so that females rendered sterile in any particular year remained so for the rest of their lives. The efficacy of fertility control alone repeated annually for varying periods of time was compared with a single culling operation and integrated control involving an initial single cull followed by annually repeated fertility control. With fertility control alone, in no instance was the disease eradicated completely while a viable badger population (mean group size of at least one individual) was still maintained. Near eradication of the disease (less than 1% prevalence) combined with the survival of a minimum viable badger population was only achieved under a very limited set of conditions, either with high efficiency of control (95%) over a short time period (1-3 years) or a low efficiency of control (20%) over an intermediate time period (10-20 years). Under these conditions, it took more than 20 years for the disease to decline to such low levels. A single cull of 80% efficiency succeeded in near eradication of the disease (below 1% prevalence) after a period of 6-8 years, while still maintaining a viable badger population. Integrated strategies reduced disease prevalence more rapidly and to lower levels than culling alone, although the mean badger group size following the onset of control was smaller. Under certain integrated strategies, principally where a high initial cull (80%) was followed by fertility control over a short (1-3 year) time period, the disease could be completely eradicated while a viable badger population was maintained. However, even under the most favourable conditions of integrated control, it took on average more than 12 years following the onset of control for the disease to disappear completely from the badger population. These results show that whilst fertility control would not be a successful strategy for the control of bovine tuberculosis in badgers if used alone, it could be effective if used with culling as part of an integrated strategy. This type of integrated strategy is likely to be more effective in terms of disease eradication than a strategy employing culling alone. However, the high cost of developing a suitable fertility control agent, combined with the welfare and conservation implications, are significant factors which should be taken into account when considering its possible use as a means of controlling bovine tuberculosis in badger populations in the UK.

Outcome after multiple colorectal tumours

BACKGROUND

Patients with primary colorectal cancers have a higher risk of development of second tumours synchronously or metachronously. This special group of patients raise a particular interest in their characteristics and outcome.

METHODS

The records of 1009 patients with colorectal cancer were scrutinized. A group with multiple cancers was identified. Perioperative investigations, patterns of follow-up, pathological variables and outcome were noted.

RESULTS

There were 22 patients with metachronous tumours and 39 with synchronous tumours following 'curative' operations in 20 and 28 respectively. There was no difference in Dukes classification between the two groups: Polyps were associated with metachronous lesions in ten of 22 patients and synchronous lesions in 17 of 39 patients. Five-year survival was 75 per cent for patients with metachronous tumours and only 18 per cent for those with synchronous tumours.

CONCLUSION

In this study patients with metachronous tumours seemed to do very well while those with synchronous lesions did very badly. There were no identifiable demographic or clinical characteristics to account for this. There is a need to study this group of patients and identify factors like tumour biology or host resistance which prevent spread of tumour.

JSJ-1, an anti-spermidine monoclonal antibody with potential clinical applications

Polyamines have been implicated in a wide variety of functions including nucleic acid synthesis and protein synthesis. Their levels have been shown to increase in response to cell growth and differentiation. Use of polyamines as prognostic indicators of proliferative disease conditions has been hindered by the lack of suitable rapid and sensitive assays. We report the characterization of an anti-spermidine antibody, JSJ-1, with novel putrescine cross reactivity. JSJ-1 cross-reacts more strongly with putrescine (11%) than with spermine (6%). This suggests that the aminobutyl group common to both putrescine and spermidine is an important element in the antibody-antigen interaction. We have demonstrated that antibody-spermidine binding is effected by increased ionic strength. This finding is consistent with the antibody-antigen interaction being ionic. The JSJ-1 antibody has been successfully used to detect increased polyamine levels in clinical serum samples and identify those with increased polyamine levels.

Barriers to black women's participation in cancer clinical trials

This study examines attitudes that may deter black women from participating in cancer research. Subjects were recruited from women who did not respond to the initial recruitment mailing for the Women's Health Initiative. Each subject was administered a 7- to 10-minute telephone survey. One third (29) of the 80 subjects were black. Fifty-six percent of black women and 71% of white women had positive attitudes toward cancer clinical trials. More than 80% of the women surveyed agreed that clinical research benefits society and increases medical knowledge. However, almost one third of the black women agreed that scientists cannot be trusted while only 4% of whites responded similarly. Additionally, 29% of black women agreed that researchers did not care about them compared with 14% of white women. Only 28% of black women felt that clinical research in the United States was ethical, and 37% had a preference to be treated by a black scientist compared with 2% of whites. Controlling for other covariates, black women had more negative altitudes overall to clinical trials than white women. These findings support the likelihood that barriers exist for the participation of blacks and other minorities in clinical research. These barriers may impact the involvement of black women in cancer clinical trials. Improving trust and creating a perception of a caring attitude from investigators are important to overcoming these barriers. The inclusion of more black scientists as leaders of cancer clinical trials also may help improve these participation rates.

Optimisation of the polymerase chain reaction

The polymerase chain reaction (PCR) is a method by which specific sequences of DNA can be copied many times, allowing detailed molecular studies to be performed on as little as a single cell. Numerous and diverse applications of PCR are being developed across all disciplines of diagnostic pathology and research, and no single protocol is appropriate for all situations. Optimising PCR requires a delicate balance between the amplification of specific products and avoiding the production of non-specific products. Each step, from DNA template extraction to cycling times and temperatures, needs to be considered carefully. The aim of this study is to assess which parameters influence DNA amplification efficiency and specificity. The parameters evaluated are the denaturation, annealing and extension temperatures, the number of cycles performed, and the primer, magnesium chloride, dNTP, Taq DNA polymerase and DNA template concentrations. The important parameters for efficient, specific amplification were denaturation time and temperature, stringent annealing temperatures and magnesium chloride concentration. The importance of DNA concentration was found to depend upon the source from which the DNA was extracted.

Factors affecting the pharmacokinetics of parenteral chloramphenicol in enteric fever

Chloramphenicol pharmacokinetics were studied in 29 Nepalese adults diagnosed with uncomplicated enteric fever and randomized to receive succinate ester 30 mg/kg i.v. or i.m. Serial plasma concentrations of chloramphenicol, and iothalamate (to estimate glomerular filtration rate), antipyrine (hepatocellular function) and Indocyanine Green (liver blood flow) were measured by HPLC and kinetic parameters estimated by non-compartmental analysis. In culture-positive patients (n = 16), mean residence times (MRTs) and steady-state volumes of distribution (V(d)ss) for i.v. chloramphenicol (mean +/- S.D.; 4.9 +/- 0.9 h and 1.9 +/- 0.8 L/kg; n = 7) were less than after i.m. chloramphenicol (12.3 +/- 7.3 h and 3.7 +/- 2.5 L/kg; n = 9; P < 0.05), with a higher peak plasma concentration after i.v. (16.2 +/- 9.1 versus 7.8 +/- 3.6 mg/L; P < 0.05); plasma clearance (Cl(p)) was similar in the two groups (368 +/- 172 and 310 +/- 224 mL/kg/min after i.v. and i.m. respectively). In 17 patients examined during convalescence, MRT and Vdss were less than in acute illness regardless of route chloramphenicol administration. There were similar changes in chloramphenicol kinetic parameters in culture-negative patients. Antipyrine Cl(p) and liver blood flow correlated weakly with chloramphenicol Cl(p) in culture-positive patients (P < 0.1) and were higher in convalescence; no such associations were seen for iothalamate Cl(p). These data indicate that i.v. chloramphenicol produces peak plasma concentrations which are on average twice those after i.m. injection of the same dose, due principally to a smaller V(d)ss. Cl(p) is uninfluenced by route of administration and is determined more by hepatic metabolism than renal excretion. Intramuscular treatment may result in sub-therapeutic chloramphenicol concentrations initially, but continued regular i.v. dosing is more likely to produce levels at which bone marrow toxicity occurs.

Running exercise may reduce risk for lung and liver cancer by inducing activity of antioxidant and phase II enzymes

The effects of exercise, ethanol, and exercise plus ethanol-treatments on activity of superoxide dismutase (SOD), catalase (CAT), glutathione-S-transferase (GST) and UDP-glucuronosyl transferase (UDP-GT) in lung and liver were investigated. All treatments induced SOD and CAT activity in the lung while CAT activity was enhanced only by the combined treatments in the liver. Ethanol reduced hepatic SOD activity, while with the combined treatment SOD was normal. Exercise enhanced UDP-GT activity in liver and lung while ethanol had no effect and GST activity was induced in the liver by the combined treatment. Thus exercise may reduce risk for lung and hepatic cancer and prevent an ethanol-induced increase in risk for hepatic cancer by enhancing activity of antioxidant and phase II enzymes.

A double-blind randomized study of the treatment of endometriosis with nafarelin or nafarelin plus norethisterone

The objective of this study was to compare the efficacy of nafarelin 200 micrograms (Group A), nafarelin 400 micrograms (Group B) and the combination of nafarelin 200 micrograms and norethisterone 1.2 mg (Group C) daily, in treating symptoms of endometriosis, American Fertility Society score and adverse events during 6 months of treatment. A prospective, randomized, double-blind parallel group study was performed in two centers and 49 women with endometriosis diagnosed laparoscopically were included. The patients were seen monthly for physical examination and records were taken for bleeding pattern, symptom score and adverse events. A control laparoscopy was performed at the end of 6 months of treatment. All patients were followed 6 months after treatment. At 3 and 6 months the pelvic examination total score had decreased significantly in all three groups. The total endometriosis score was significantly reduced in Groups B and C. After 2 months the total symptom score showed a significant decrease in Groups B and C. The frequency of hot flushes during the first month of treatment was lowest in Group C, but during the rest of treatment there were no differences between the groups. Best bleeding control was obtained in Group C. We conclude that nafarelin 200 micrograms daily has as good an effect on endometriosis symptoms as nafarelin 400 micrograms daily, and the addition of norethisterone 1.2 mg results in fewer hot flushes and better bleeding control.

pPV: a novel IRES-containing vector to facilitate plasmid immunization and antibody response characterization

BACKGROUND

The ability to derive immunological reagents for basic and applied research in a timely fashion is a basic requirement of many research projects and is becoming increasingly important as the number of novel gene products of potential interest continues to evolve rapidly. DNA immunization provides a means of facilitating the production of antibody reagents by circumventing the need to derive either purified protein or define peptides before initiating an in vivo immunization protocol.

OBJECTIVES

The DNA construct pPV, for plasmid vaccination, has been designed to facilitate the generation and characterization of antibody reagents against either random or defined molecular targets.

STUDY DESIGN

pPV incorporates mammalian regulatory and structural features that promote expression of a bifunctional messenger RNA (mRNA) from a single promoter within mammalian cells both in vitro and in vivo. The bifunctional mRNA encodes a control epitope (human IL5), and the 'test' epitope expressed as a tagged recombinant polypeptide in either a random 'shot-gun' mode or a predetermined fashion. In addition, to aid subsequent characterization of antibody responses elicited in vivo, a T7 promoter is included to enable in vitro expression of tagged recombinant polypeptides.

RESULTS

The utility and functionality of pPV for the in vitro expression of recombinant protein and the in vivo elicitation of antibody responses is illustrated using a defined 'test' epitope, human proIL1 beta.

CONCLUSION

It is anticipated pPV will find particular utility in the future rapid generation and characterization of antibody reagents against the plethora of novel genes emerging from ongoing genomics activity in a directed or genome wide fashion.

Recurrent Streptococcus pneumoniae sepsis in children with sickle cell disease

Streptococcus pneumoniae sepsis is the most common invasive infection among patients with sickle cell disease. The risk of a recurrent episode of sepsis and subsequent death in those patients who have had a previous septic event is much higher. Patients with sickle disease who have had pneumococcal sepsis should continue penicillin prophylaxis indefinitely and should not be candidates for out-patient management of febrile episodes.

Pulmonary surfactant protein SP-B interacts similarly with dipalmitoylphosphatidylglycerol and dipalmitoylphosphatidylcholine in phosphatidylcholine/phosphatidylglycerol mixtures

Porcine pulmonary surfactant-associated protein SP-B was incorporated into bilayers of chain-perdeuterated dipalmitoylphosphatidylglycerol (DPPG-d62) and into bilayers containing 70 mol % dipalmitoylphosphatidylcholine (DPPC) and 30 mol % DPPG-d62 or 70 mol % chain-perdeuterated DPPC (DPPC-d62) and 30 mol % DPPG. The effect of SP-B on the phase behavior, lipid chain order, and dynamics in these bilayers was examined using deuterium nuclear magnetic resonance (2H-NMR). In both DPPG-d62 and the mixed lipid system, SP-B is found to have little effect on chain order in the liquid crystalline phase. With 11% (w/w) SP-B present, both bilayer systems display a continuous change from liquid crystal to gel with no evidence of two-phase coexistence near the transition. Despite its limited effect on chain order in these bilayers, SP-B is found to strongly perturb chain deuteron transverse relaxation in the liquid crystal and gel phases of DPPG-d62 and the DPPC/DPPG (7:3) mixtures. The observation that SP-B associates with the bilayer in a way which substantially alters the slow motions responsible for transverse relaxation without significantly affecting chain order in either the liquid crystal or gel phases may place some constraints on possible models for that association.

Evaluation of indapamide 1.25 mg once daily in elderly patients with mild to moderate hypertension

The objective of this study was to evaluate the safety and efficacy of indapamide 1.25 mg once daily as monotherapy in elderly patients (65 years and older) with mild to moderate essential hypertension. Two hundred and seventy-nine (279) elderly patients were enrolled in a washout period, during which patients received single-blind placebo for 4 weeks. Patients demonstrating supine diastolic pressures between 95 mm Hg and 114 mm Hg at the end of the 4-week placebo washout period were entered into the 8-week double-blind treatment period. Two hundred and four (204) patients qualified for the study and were randomized to the double-blind treatment; 103 patients received indapamide 1.25 mg and 101 patients received placebo for 8 weeks. Overall, 177 patients (92 indapamide and 85 placebo) completed the study. The primary efficacy criterion was the mean change in supine diastolic blood pressure (DBP) from double-blind baseline to the end of 8 weeks of therapy. By week 8 of the double-blind treatment period, indapamide 1.25 mg produced a statistically significant (P = 0.0037) decrease in supine DBP of 8.2 mm Hg compared to a decrease of 5.3 mm Hg produced in the placebo group. Additionally, indapamide 1.25 mg was statistically (P = 0.0028) more effective than placebo in reducing supine systolic BP (SBP) (-10.1 vs -4.2 mm Hg). The incidence of drug-related adverse events during the double-blind treatment period was similar between the two treatment groups. A low dose of indapamide, 1.25 mg, given once daily for 8 weeks was effective as monotherapy with respect to BP reduction in an elderly population with mild to moderate hypertension. Indapamide 1.25 mg was safe and generally well tolerated in this elderly patient population.

Outcomes of long-term ventilator patients: a descriptive study

BACKGROUND

Long-term ICU patients who require prolonged mechanical ventilation are a growing segment of the in-hospital population. Despite recognition that this population is costly to care for no systematic research has been done on the characteristics, outcomes, and disposition of these patients after they leave the hospital.

OBJECTIVE

To describe clinical and sociodemographic characteristics and outcomes of ICU patients who require long-term (5 days or more) mechanical ventilation while in the hospital.

METHODS

A prospective, longitudinal descriptive design was used to study 57 ICU patients who required 5 days or more of continuous mechanical ventilation while in the hospital. Clinical and sociodemographic data were collected at the time of enrollment. Patients were followed up for up to 6 months after discharge from the hospital to ascertain disposition and morality.

RESULTS

On average, patients had a hospital stay of almost 6 weeks and required mechanical ventilation for approximately 4 weeks; 43.9% of the patients died in the hospital. None of the patients discharged from the hospital were able to return home initially without assistance. By 6 months after discharge, more than 50% of the original sample and died, 9% resided in an institution, and 33% were living at home.

CONCLUSIONS

A large percentage of ICU patients who require 5 days or more of mechanical ventilation die in the hospital, and many of those who live spend considerable time in an extended-care facility before they are discharged to their homes. These likely outcomes of patients who require long-term ventilation should be discussed with patients and their families to assist them in making informed decisions.

Outcomes of long-term ventilator patients: a descriptive study

BACKGROUND: Long-term ICU patients who require prolonged mechanical ventilation are a growing segment of the in-hospital population. Despite recognition that this population is costly to care for no systematic research has been done on the characteristics, outcomes, and disposition of these patients after they leave the hospital. OBJECTIVE: To describe clinical and sociodemographic characteristics and outcomes of ICU patients who require long-term (5 days or more) mechanical ventilation while in the hospital. METHODS: A prospective, longitudinal descriptive design was used to study 57 ICU patients who required 5 days or more of continuous mechanical ventilation while in the hospital. Clinical and sociodemographic data were collected at the time of enrollment. Patients were followed up for up to 6 months after discharge from the hospital to ascertain disposition and morality. RESULTS: On average, patients had a hospital stay of almost 6 weeks and required mechanical ventilation for approximately 4 weeks; 43.9% of the patients died in the hospital. None of the patients discharged from the hospital were able to return home initially without assistance. By 6 months after discharge, more than 50% of the original sample and died, 9% resided in an institution, and 33% were living at home. CONCLUSIONS: A large percentage of ICU patients who require 5 days or more of mechanical ventilation die in the hospital, and many of those who live spend considerable time in an extended-care facility before they are discharged to their homes. These likely outcomes of patients who require long-term ventilation should be discussed with patients and their families to assist them in making informed decisions.

Merger motorway. Giving staff the tools to reengineer

Mergers and health care agencies' response to mergers dominate current conversations in this evolving managed care environment. Hospitals are rapidly learning to adjust to declining occupancy rates and deceased utilization of resources. A business model to guide mergers was adapted to assist staff with the people, structural, cultural and political issues of organizational change. Creating successful new work environments, moving from a "We-they" mentality to unity and decreasing use of resources are outcomes described in this article.

Effects of farm management practices on cattle grazing behaviour and the potential for transmission of bovine tuberculosis from badgers to cattle

Despite the large body of circumstantial evidence to suggest a link, the means by which bovine tuberculosis is passed from badgers to cattle remains unclear; pasture contamination with the urine, faeces and/or sputum of infectious badgers is believed to be the main route of transmission. Therefore the behaviour of grazing cattle was studied to determine whether they avoided investigating and/or grazing pasture contaminated with badger excreta, and whether different farm management practices enhanced the potential for disease transmission. Active latrines were avoided by most cattle until the sward length in the rest of the field was reduced, after which there was an increasing likelihood that active badger latrines would be grazed. Most of the cattle grazed active badger latrines, but cattle of low rank within the herd grazed latrines more heavily. Farm management practices that reduced the availability of long swards shortened the period of investigative behaviour and greatly enhanced the risk that cattle would graze active badger latrines. Cattle were more likely to graze pasture away from latrines that was contaminated either with badger urine or single faeces. Because bacilli remain viable in the soil for up to 2 years, there is the potential for bacilli to accumulate at active badger latrines, and these could pose a significant risk to cattle, even when the latrine is no longer being used by badgers. Cattle readily grazed the lush sward at disused latrines, during which they could ingest contaminated soil; the amount of soil ingested increases as sward length decreases.

Effects of human tumor cell lines on local new bone formation in vivo

Although some tumors cause osteolytic lesions, there are some that stimulate new bone formation. This is an important phenomenon because the responsible mechanisms probably represent an aberration of normal physiological bone formation, and identifying the factors involved in the process may lead to new therapies for various bone diseases. To clarify our understanding of the potential mechanism responsible, we compared and quantitated the extent of new bone formation stimulated by human tumors (HeLa, Hep-2, AV-3, FL, WISH and KB), some of which have osteogenic activity in vivo [2]. Tumor cells were injected over the calvaria of nude mice to examine formation of new bone. The tumor cells produced three histologically distinct patterns of new bone growth: (1) WISH and KB stimulated appositional bone growth adjacent to periosteal bone surfaces; (2) HeLa and Hep2 induced new bone growth over calvarial surface even when distant from the tumor mass; (3) FL stimulated bone formation adjacent to periosteum as well as ectopic bone formation in sites distant from bone. All tumors except AV3 induced mean new bone thickness >100 microm, and Hep-2 cells produced bone 330 microm thick. PCR and Northern blot analysis of mRNA isolated from cultured tumor cells revealed that all cell lines expressed mRNA for TGFbeta, (fibroblast growth factor) FGF-1, FGF-2, and IGF-I, and most cell lines produced mRNA for PDGF. Only FL expressed large amounts of mRNA for BMP2. In serum-free conditioned media from Hep2 and HeLa cells purified by heparin affinity chromatography, we have identified FGF-I, FGF-2, and PDGF by immunodetection with specific antibodies. Our results show that new bone growth caused by these tumors is likely due to the production of bone growth factors by the tumor cells, and that the overall effects on bone may be due to several factors working in concert.