Development and Initial Characterization of Xenomitochondrial Mice

Xenomitochondrial mice harboring trans-species mitochondria on a Mus musculus domesticus (MD) nuclear background were produced. We created xenomitochondrial ES cell cybrids by fusing Mus spretus (MS), Mus caroli (MC), Mus dunni (Mdu), or Mus pahari (MP) mitochondrial donor cytoplasts and rhodamine 6-G treated CC9.3.1 or PC4 ES cells. The selected donor backgrounds reflected increasing evolutionary divergence from MD mice and the resultant mitochondrial-nuclear mismatch targeted a graded respiratory chain defect. Homoplasmic (MS, MC, Mdu, and MP) and heteroplasmic (MC) cell lines were injected into MD ova, and liveborn chimeric mice were obtained (MS/MD 18 of 87, MC/MD 6 of 46, Mdu/MD 31 of 140, and MP/MD l of 9 founder chimeras, respectively). Seven MS/MD, 1 MC/MD, and 11 Mdu/MD chimeric founder females were mated with wild-type MD males, and 18 of 19 (95%) were fertile. Of fertile females, only one chimeric MS/MD (1% coat color chimerism) and four chimeric Mdu/MD females (80-90% coat color chimerism) produced homoplasmic offspring with low efficiency (7 of 135; 5%). Four male and three female offspring were homoplasmic for the introduced mitochondrial backgrounds. Three male and one female offspring proved viable. Generation of mouse lines using additional female ES cell lineages is underway. We hypothesize that these mice, when crossbred with neurodegenerative-disease mouse models, will show accelerated age-related neuronal loss, because of their suboptimal capacity for oxidative phosphorylation and putatively increased oxidative stress.

Modified directly observed therapy for the treatment of HIV-seropositive substance users: lessons learned from a pilot study

Highly active antiretroviral therapy (HAART) can dramatically decrease human immunodeficiency virus (HIV) load in plasma, increase CD4+ cell counts, and prolong life for HIV-seropositive persons. However, the need for optimal adherence has been recognized. We implemented a pilot community-based program of directly observed therapy (DOT) with HAART among persons with substance use disorders and a history of failure of HAART. A near-peer outreach worker initially delivered and observed once-daily HAART doses on up to 7 days per week. Many participants tapered the frequency of visits. Participants were assessed by a brief questionnaire and determination of their CD4+ cell count and plasma HIV load. Twenty-five HIV-seropositive persons were enrolled and followed-up for a mean of 6.6 months (standard deviation, 3.9 months). We found that once-daily dosing of HAART by DOT is feasible in this population; in addition to observation of the majority of doses, most participants achieved virus suppression and felt favorably about the intervention. Tapering the intensity of visits with maximum flexibility was necessary to enhance the acceptability of the program to participants.

Radiation induced mucositis: co-ordinating a research agenda

AIMS

A one-day workshop was hosted by the Symptom Control Committee of the National Cancer Institute of Canada, Clinical Trials Group (NCIC-CTG), in conjunction with the October 2002 annual meeting of the Canadian Association of Radiation Oncologists in Toronto, Ontario. The primary intention of the workshop was to direct the future research agenda of the Symptom Control Committee. Large group presentations were held initially to review the contemporary research issues of four selected areas of interest: fatigue, brain metastasis, bone metastasis and radiation-induced mucositis. Panel members were then charged with the identification of specific research proposals that could be considered for further development. Research questions were to be clinically relevant and currently appropriate. Any additional information needed before the launch of any potential trial was also requested. In this paper, we will review and summarise the outcomes from the radiation-induced mucositis sessions.

MATERIALS AND METHODS

Thirty-four participants participated in the large group sessions and contributed to one of four panel discussions on selected supportive care issues relevant to radiation oncologists.

RESULTS

Three potential and non-overlapping research questions were identified; two involving mucositis management in patients receiving radical radiation for head and neck cancer, and a third for patients with advanced lung cancer undergoing combined radiation and chemotherapy and at risk for the development of symptomatic oesophagitis.

CONCLUSION

The workshop successfully identified three potential research questions. The large group and the smaller panel discussions successfully established consensus on important aspects of future study designs. The current 'standard of care', appropriate experimental treatments, primary outcomes of interest and study population parameters were each important issues that were discussed. The importance of developing meaningful biological assays was reviewed, as was the need to ensure the appropriate storage of biological samples from patients for future study.

A syringe prescription program to prevent infectious disease and improve health of injection drug users

Injection drug users (IDUs) are at increased risk for many health problems, including acquisition of human immunodeficiency virus (HIV) and hepatitis B and C. These risks are compounded by barriers in obtaining legal, sterile syringes and in accessing necessary medical care. In 1999, we established the first-ever syringe prescription program in Providence, Rhode Island, to provide legal access to sterile syringes, reduce HIV risk behaviors, and encourage entry into medical care. Physicians provided free medical care, counseling, disease testing, vaccination, community referrals, and prescriptions for sterile syringes for patients who were not ready to stop injecting. We recruited 327 actively injecting people. Enrolled participants had limited stable contact with the health care system at baseline; 45% were homeless, 59% were uninsured, and 63% did not have a primary care physician. Many reported high-risk injection behaviors such as sharing syringes (43% in the last 30 days), reusing syringes (median of eight times), and obtaining syringes from unreliable sources (80%). This program demonstrates the feasibility, acceptability, and unique features of syringe prescription for IDUs. The fact that drug use is acknowledged allows an open and frank discussion of risk behaviors and other issues often not disclosed to physicians. The syringe prescription program in Providence represents a promising and innovative approach to disease prevention and treatment for IDUs.

Would you consider prescribing syringes to injection drug users? Addiction Medicine Conference Survey

In order to assess attitudes and practices of physicians regarding prescribing syringes to injection drug users (IDUs) to prevent disease transmission, a survey was conducted at the 2000 ASAM Conference. Of 497 physicians, 104 responded, representing 30 states and 3 countries. Seventy-eight percent provided care for IDUs. Only 2% had prescribed syringes to IDUs for safer injection of illegal drugs. Nineteen percent had prescribed syringes to diabetic patients whom they believed would use the syringes for injecting illegal drugs. Overall, 61% of physicians (74% of internists, 37% of psychiatrists) (p = 0.04) would consider prescribing syringes to IDUs. Prescribing syringes to IDUs can be part of a comprehensive approach to preventing spread of HIV and other infections, decreasing complications of syringe reuse, and bringing IDUs into medical and substance abuse treatment. The majority of physicians surveyed expressed interest in prescribing syringes. Psychiatrists may be less willing to do so.

Aftercare attendance and post-treatment functioning of severely substance dependent residential treatment clients

The present study evaluated the impact of a structured aftercare programme following residential treatment for severe alcohol and/or heroin dependent clients. Over 17 months, 77 participants were recruited to the study and allocated randomly to either a structured aftercare (SA) programme or to unstructured aftercare (UA) of crisis counselling on request. Independent clinicians interviewed participants and collaterals, at 4-month (median) intervals, for 12 months following residential treatment. SA compared to UA was associated with a fourfold increase in aftercare attendance and one-third the rate of uncontrolled principal substance use at follow-up. Participants who attended either type of aftercare relapsed a median of 134 days later than those who attended no aftercare. Overall, 23% of monitored participants remained abstinent throughout, 21% maintained controlled substance use and 56% relapsed, within a median of 36 days following residential treatment. The only significant predictor of days to relapse, controlling for age, was pretreatment use of additional substances. Participants with pretreatment additional substance use relapsed a median of 192 days earlier than those who had used no other substances. The degree of agreement between participant self-reports and collateral reports was fair-to-moderate and moderate among collaterals. Intention-to-treat analyses revealed significant and clinically meaningful reductions in substance use in this sample of severely dependent residential treatment clients. The generalizability of these results is limited because of significant differences in age and presenting substance between the study sample and other clients admitted to the service during the study. This latter group of younger, male, heroin-dependent clients with polydrug use who refuse opioid pharmacotherapy, are more likely to drop out of treatment or relapse early following treatment and continue to present a challenge to treatment services.

The use of resolvases T4 endonuclease VII and T7 endonuclease I in mutation detection

Mutation and polymorphism detection is of increasing importance in the field of molecular genetics. This is reflected by the plethora of chemical, enzymatic, and physically based methods of mutation detection. The ideal method would detect mutations in large fragments of DNA and position them to single base-pair (bp) accuracy. Few methods are able to quickly screen kilobase lengths of DNA and position the mutation at the same time. The Enzyme Mismatch Cleavage (EMC) method of mutation detection is able to reliably detect nearly 100% of mutations in DNA fragments as large as 2 kb and position them to within 6 bp. This method exploits the activity of a resolvase enzyme from T4, T4 endonuclease VII, and, more recently, a second bacteriophage resolvase, T7 endonuclease I. The technique uses these enzymes to digest heteroduplex DNA formed by annealing wild-type and mutant DNA. Digestion fragments indicate the presence, and the position, of any mutations. The method is robust and reliable and much faster and cheaper than sequencing. These attributes have resulted in its increasing use in the field of mutation detection.

Whole blood impedance aggregometry for the assessment of platelet function in patients with congestive heart failure (EPCOT Trial)

OBJECTIVE

Data from small studies have shown the presence of platelet abnormalities in patients with congestive heart failure (CHF). We sought to characterize the diagnostic utility of the whole blood aggregometry (WBA) in a random outpatient CHF population.

METHODS

Blood samples were obtained for measurement of whole blood aggregation, shear-induced closure time, platelet contractile force, expression of GP IIb/IIIa, and P-selectin in 100 consecutive patients with CHF.

RESULTS

Substantial inter-individual variability of platelet characteristics exists in patients with CHF. There were no statistically significant differences when patients were divided by the incidence of vascular events, emergency revascularization needs, survival, or etiology of heart failure. Surprisingly, aspirin use did not affect instrument readings as well. Whole blood aggregometry correlates well with the closure time (r(2)=0.587), and with GP IIb/IIIa expression (r(2)=0.435). Significant but less strong correlation has been observed for the WBA with platelet P-selectin expression (r(2)=0.295), and no correlation was present for the platelet contractile force measures (r(2)=0.030).

CONCLUSIONS

Despite the fact that patients with heart failure enrolled in the EPCOT trial exhibited marginal, sometimes oppositely directed changes, in their platelet characteristics, whole blood impedance aggregometry is indeed capable to serve as a valuable diagnostic tool, and may be successfully used as an established screening device in this population. Ability of the whole blood aggregometry to predict clinical outcomes, or for the monitoring of anti-platelet agents in CHF patients, will be evaluated in the ongoing clinical trials.

Epoetin alfa therapy increases hemoglobin levels and improves quality of life in patients with cancer-related anemia who are not receiving chemotherapy and patients with anemia who are receiving chemotherapy

PURPOSE

To evaluate efficacy, safety, and quality of life (QOL) changes with epoetin alfa therapy for anemia in patients with nonmyeloid malignancies.

PATIENTS AND METHODS

Anemic cancer patients were enrolled onto this prospective, open-label study from 34 centers across Canada. The trial had two cohorts: patients who were and were not receiving chemotherapy during the 16-week study. All patients initially received epoetin alfa 150 IU/kg subcutaneously three times per week. The dose was doubled after 4 weeks for patients who did not experience sufficient response.

RESULTS

Of the 183 patients enrolled in the nonchemotherapy cohort, statistically significant and clinically relevant improvements in QOL were observed with epoetin alfa therapy using both the FACT-An questionnaire and linear analog scale assessment. Hemoglobin levels increased significantly (P <.001; mean increase 2.5 g/dL from baseline to end of study) and these increases were positively correlated with improved QOL and change in Eastern Cooperative Oncology Group (ECOG) scores. There was a significant reduction in the percentage of patients who required blood transfusions. The 218 patients in the chemotherapy cohort also experienced significant improvements in QOL, decreased transfusion use, and increased hemoglobin levels that correlated with QOL improvements and change in ECOG scores. Epoetin alfa was well-tolerated in both cohorts.

CONCLUSION

Epoetin alfa administered to patients with cancer-related anemia for up to 16 weeks resulted in significantly improved QOL, increased hemoglobin levels, and decreased transfusion use. These benefits were observed in cancer patients who were not receiving chemotherapy as well as those who were.

AlphaIIb's cytoplasmic domain is not required for ligand-induced clustering of integrin alphaIIbbeta3

The platelet integrin alphaIIbbeta3 exhibits bidirectional signaling, in that intracellular messengers enable adhesive macromolecules to bind to its ectodomain, while ligation promotes the association of cytoskeletal proteins with its cytoplasmic domains. In order to understand the linkage between these distant regions, we investigated the effects of receptor occupancy on the solution structure of both full-length recombinant alphaIIbbeta3 and alphaIIbDelta991beta3, an integrin truncation mutant which lacks one cytoplasmic domain. Lysates of (35)S-labeled human A549 cells expressing either full-length alphaIIbbeta3 or alphaIIbDelta991beta3 were examined by sucrose density gradient sedimentation followed by immunoprecipitation to determine the distributions of integrin protomers and oligomers. Recombinant alphaIIbbeta3 exhibited a weight-average sedimentation coefficient, S(w)=11.3+/-1.4 S with 73% sedimenting as protomers/dimers (9.1+/-1.0 S) and 27% as oligomers (15.4+/-0.4 S). Truncation mutant alphaIIbDelta991beta3 exhibited a similar pattern with 65% sedimenting as protomers/dimers. Upon ligation with eptifibatide, both full-length alphaIIbbeta3 and alphaIIbDelta991beta3 sedimented mainly at >14 S, indicating 2-3-fold increased oligomerization. Thus we have demonstrated that alphaIIb's cytoplasmic region is not required for integrin clustering, a key event in outside-in signaling.

Enhancing adherence to HAART: a pilot program of modified directly observed therapy

Based on the model of directly observed therapy (DOT) for tuberculosis, we implemented an uncontrolled pilot program of modified DOT to increase adherence to HAART. Participants met every weekday with an outreach worker who observed them taking the morning dose of HAART. Thirty-seven patients with a history of poor adherence were enrolled and followed for a mean duration of 10 months. The program was feasible and well accepted by the participants. Self-reported adherence to nonobserved doses improved, and those who remained in the program for a year (n = 18) demonstrated a mean 1.53-log decrease from baseline in plasma HIV RNA level.

Syringe prescription to prevent HIV infection in Rhode Island: a case study

Injection drug users (IDUs) are a population at high risk for many diseases, including AIDS, and are clearly in need of medical and substance abuse treatment. Access to sterile syringes is critical for lowering the risk of transmission of HIV and other blood-borne pathogens among IDUs. Previously tried strategies include needle exchange programs and changing laws to allow the legal purchase and possession of syringes. An alternative strategy is to have physicians prescribe syringes to IDUs. To the best of our knowledge, this has previously been tried by only a few physicians in rare situations and never on a programmatic basis. This report describes the genesis of physician's syringe prescription in Rhode Island and some of the lessons learned to date. Because of the illicit nature of drug use, a tremendous amount of mistrust and fear on the part of IDUs often leads to poor interaction with the medical establishment. Prescription of syringes by a physician can serve as a tool for reaching out to a high-risk and often out-of-treatment population of drug users. It is a way for the health care community to tap into drug-using networks and bring those populations into a medical care system.

Prescribing syringes to prevent HIV: a survey of infectious disease and addiction medicine physicians in Rhode Island

This article describes the assessment of physicians' attitudes and practices regarding prescribing syringes to injection drug users (IDUs). A brief, anonymous, self-administered questionnaire was sent to all Infectious Disease and Addiction Medicine specialists in Rhode Island. Of 49 eligible physicians, 39 responded (response rate 80%). Most (95%) indicated that there is a legitimate medical reason for IDUs to obtain sterile syringes. Many (71%) agreed that they would prescribe syringes to prevent disease in IDUs if it were clearly legal to do so. We can conclude that physician syringe prescription to IDUs may be an acceptable supplement to existing HIV prevention strategies.

Differences in length of stay for Hospital in the Home patients: comparing simple clinical coding with medical record review

AIM

To determine whether the apparently longer length of stay (LOS) reported for patients with cellulitis managed in Hospital in the Home (HITH) compared with those managed as inpatients was correct.

METHODS

Data, including LOS, from the Victorian In-patient Minimum Database (VIMD) of all patients with cellulitis managed between July 1998 and June 1999 at a large metropolitan teaching hospital were analysed and compared with a retrospective medical record review of the same patients.

RESULTS

In the VIMD data, there were 266 episodes of cellulitis during the study period. However, the medical record review found that six episodes were not separate, but rather a continuation of treatment for the same episode of cellulitis, and that 18 were not episodes of cellulitis, but were pilonidal sinus infections. In the VIMD data set, the mean LOS for patients treated in HITH was generally longer than that for inpatients (7.2 days vs 5.1 days, respectively, P = 0.002). However, in the retrospective medical record review, the LOS for patients treated in HITH was similar to inpatients (7.3 days versus 7.0 days, respectively, P = 0.68).

CONCLUSIONS

In contrast to the VIMD data, the medical record review demonstrated that, overall, patients with cellulitis had a similar LOS irrespective of whether they were managed at home or in hospital. This study confirms that caution is required in interpreting the VIMD data, highlights the importance of carefully monitoring the introduction of new treatment modalities and indicates areas for further research.

Treating cancer patients. Practical monitoring and management of therapy-related complications

OBJECTIVE

To review investigation and management of some common long-term complications associated with cancer chemotherapy and radiation therapy.

QUALITY OF EVIDENCE

Databases searched using MeSH key words "cancer chemotherapy," "cancer chemotherapy complications," "radiation therapy," and "radiation therapy complications" included Ovid and CANCERLIT. Overall the literature in this area is not strong; treatment guidelines and consensus conferences generally are lacking. Recommendations in this paper are mainly based on the results of individual studies and case reports, as few randomized controlled trials have been performed. Where appropriate, recommendations incorporate results of published treatment guidelines and consensus conferences.

MAIN MESSAGE

For most solid tumours, patients should be most frequently monitored during the first 3 years after completing initial treatment for cure. Follow-up monitoring usually incorporates physical examination as well as radiologic and laboratory investigations. Patients should not be lost to follow up once treatment is completed, but monitored regularly, especially while they are at highest risk for disease recurrence. Long-term complications associated with cancer therapy include postsplenectomy sepsis syndrome; central and peripheral nervous system toxicities; ocular complications; thyroid, pituitary, testicular, or ovarian dysfunction; pulmonary toxicity; vascular or lymphatic, gastrointestinal, or osseous complications; genitourinary problems; and possible secondary malignancy.

CONCLUSION

Primary care physicians are key to facilitating appropriate follow up of treated cancer patients. To do this, they must be aware of practical aspects of monitoring and management of therapy-related complications.

Skin blood flow changes in response to intradermal injection of bupivacaine and levobupivacaine, assessed by laser Doppler imaging

BACKGROUND AND OBJECTIVES

The vascular effects of local anesthetics are important determinants of their therapeutic activity. Drugs that vasoconstrict have the potential clinical advantages of limited systemic uptake and prolonged duration of effect. The aim of this study was to assess quantitatively the cutaneous vasoactivity of racemic bupivacaine and one of its enantiomers, levobupivacaine.

METHODS

Four concentrations of each drug (0.1 mL each of 0.125%, 0.25%, 0.5%, and 0.75%), as well as normal saline, were injected intradermally into randomly assigned sites on the forearms of 10 volunteers. We measured skin blood perfusion using laser Doppler imaging before injection and at 2.5, 10, 20, 40, 60, and 90 minutes thereafter.

RESULTS

Both drugs produced a rapid, dose-dependent increase in skin perfusion (P <.001). Saline also caused an increase in perfusion, although less sustained. By 40 minutes, most responses had returned to baseline levels. However, after this time, perfusion continued to decrease, below baseline, for both bupivacaine and levobupivacaine. The exception to this was 0.75% bupivacaine, the response to which was significantly higher than the same concentration of levobupivacaine over this later period (P <.05).

CONCLUSIONS

Bupivacaine and levobupivacaine both have a biphasic effect on skin microvessels. The vasoconstriction observed after 40 minutes may occur when the quantity of drug remaining at the administration site has decreased to a lower level. The continued vasodilatation caused by bupivacaine is more difficult to interpret. The results suggest that these local anesthetics cause vasodilatation at high doses and vasoconstriction at lower, subclinical doses. This hypothesis and the clinical relevance of these effects warrant further investigation.

Expression of Rattus norvegicus mtDNA in Mus musculus cells results in multiple respiratory chain defects

The production of in vitro and in vivo models of mitochondrial DNA (mtDNA) defects is currently limited by a lack of characterized mouse cell mtDNA mutants that may be expected to model human mitochondrial diseases. Here we describe the creation of transmitochondrial mouse (Mus musculus) cells repopulated with mtDNA from different murid species (xenomitochondrial cybrids). The closely related Mus spretus mtDNA is readily maintained when introduced into M. musculus mtDNA-less (rho(0)) cells, and the resulting cybrids have normal oxidative phosphorylation (OXPHOS). When the more distantly related Rattus norvegicus mtDNA is transferred to the mouse nuclear background the mtDNA is replicated, transcribed, and translated efficiently. However, function of several OXPHOS complexes that depend on the coordinated assembly of nuclear and mtDNA-encoded proteins is impaired. Complex I activity in the Rattus xenocybrid was 46% of the control mean; complex III was 37%, and complex IV was 78%. These defects combined to restrict maximal respiration to 12-31% of the control and M. spretus xenocybrids, as measured polarographically using isolated cybrid mitochondria. These defects are distinct to those previously reported for human/primate xenocybrids. It should be possible to produce other mouse xenocybrid constructs with less severe OXPHOS phenotypes, to model human mtDNA diseases.

High street prices of syringes correlate with strict syringe possession laws

The current epidemic of injection drug use in the United States and abroad has precipitated an increase in transmission of infectious diseases, including human immunodeficiency virus (HIV), hepatitis B, hepatitis C, and human T-lymphotrophic virus II (HTLV-II) in injection drug users (IDUs) who share syringes and other injection equipment. Sharing is often due to a lack of available sterile syringes, which is, in part, a result of laws and regulations controlling the purchase and possession of syringes. These laws, in turn, raise the price of questionably sterile black market syringes, inadvertently encouraging the reuse and sharing of syringes. To date, very little information has been gathered on the street price of syringes in different communities. We surveyed 42 needle exchange programs (NEPs) in the United States in July and August 1998 to determine the street prices of syringes. The relationship among local laws regulating syringe possession, the enforcement of those laws, and street syringe prices was examined. There was a strong correlation between the presence of syringe possession laws and higher street syringe price ($2.87 vs. $1.14, p< .01). In areas with syringe possession laws, cost was significantly higher when laws were perceived to be enforced strictly ($3.66 vs. $2.08, p<.01). Street prices for syringes are an easily quantifiable indirect measure of availability of sterile syringes and may reflect syringe sharing and reuse.

The carers of hospital in the home patients focus on clinical processes, procedures and the prediction of deterioration

The aim of this study was to explore the psychological processes and information needs in a group of 78 Hospital-in-the-Home (HITH) carers, randomly selected from two university teaching hospital HITH programs in Melbourne. Semi-structured interviews were conducted and explored with a computerised lexical thematic content analysis program. The results revealed that psychological themes of carers were mainly related to HITH clinical processes, procedures and the prediction of complications or deterioration of the patient. Carers indicated that they needed further information on the patients' clinical conditions, emergency procedures and how to detect deterioration. The implication for HITH nurses is that information provided to HITH carers should at least include these topics. The information needs of HITH carers appear to be different to those of the carers of individuals with chronic illness, consequently, nurses need to develop very specific patient and carer information materials for the HITH setting.

Chemotherapy standards for hospital in the home: how useful?

The process of developing practice standards is complex and resource intensive. The aim is to produce standards that meet the practicalities of clinical practice, are meaningful and achievable and that enhance the quality of patient care. This article details the process of developing chemotherapy standards for Hospital in the Home (HITH) and describes the results of a pilot project and the implications for nursing practice in this relatively new area of care delivery. Five Melbourne metropolitan Hospital in the Home (HITH) programs participated in the pilot process and evaluated the standards against their own programs. There was a wide variation in the skill sets nurses required depending on the structure of the HITH program. There were differences between programs in the nature of the interventions provided at home, documentation of treatments and points of contact for patients out of hours. Areas of concern identified by staff in the participating programs included the level of detail the standards required for assessment of the patients' home as an appropriate site to administer chemotherapy and the qualifications required by staff managing HITH chemotherapy patients.