In conflict with conflict

In a qualitative, retrospective case study to identify, describe, and develop a theoretical analysis of perceived group process among female nursing educators/administrators, the term "conflict," as traditionally defined in discussions of "conflict management strategies," was rejected. The term did not readily fit with the management styles of the 27 female nurse educators and administrators. Participants rejected "conflict" as a term. The word was deliberately avoided. In fact, conflict rejection was a specific administrative process identified as part of the successful working of the group over the three-year period studied. This finding indicates a break with traditional male-oriented literature and therefore may have implications for future research into conflict management strategies, especially into successful management strategies used by women and health care professionals.

Ex vivo adenovirus-mediated gene transfer and immunomodulatory protein production in human cornea

One attractive strategy to prevent or control allograft rejection is to genetically modify the donor tissue before transplantation. In this study, we have examined the feasibility of gene transfer to human corneal endothelium, using a number of recombinant adenovirus constructs. Ex vivo infection of human corneas with adenoviral vectors containing lacZ, under transcriptional control of either cytomegalovirus (CMV) or Rous sarcoma virus (RSV) promoters, provided high-level gene expression, which was largely restricted to endothelium. Expression of the reporter gene persisted at relatively high levels for up to 7 days, followed by a decline to indetectable levels by 28 days. RT-PCR analysis of lacZ transcription showed a similar picture with a short period (3-7 days) of RNA transcription after infection. In contrast, adenoviral DNA persisted for at least 56 days. Subsequently, we examined the expression of a potential therapeutic gene, CTLA-4 Ig fusion protein. Following infection of human corneas with adenoviral vectors encoding CTLA-4 Ig protein, high levels of the fusion protein were detected in corneal culture supernatants for up to 28 days. This protein was functionally active, as determined by binding to B7.1 (CD80)-expressing transfectants. This study suggests that genetic alteration of donor cornea before transplantation is a feasible approach for preventing or controlling allograft rejection. Similar gene-based strategies might also be feasible to prevent rejection of other transplanted tissues or organs.

Effect of cryoprotectants on the survival of follicles in frozen mouse ovaries

Ovaries from 10-day-old mice were exposed to 1.5 mol l-1 dimethylsulfoxide, 1,2-propanediol, ethanediol or glycerol for 5-60 min at room temperature before freezing. Follicles in fresh and frozen ovaries were counted and scored as normal or damaged in stained serial sections. More primordial follicles survived in ovaries frozen in dimethylsulfoxide, 1,2-propanediol and ethanediol (81-94%) than in those frozen in glycerol (4-28%). Prolonged exposure to ethanediol (60 min) before cooling decreased the survival rate, while increasing the exposure to glycerol (> or = 12 min) increased the survival rate. Fewer than 49% of primary follicles survived freezing. After transfer underneath the kidney capsules of ovariectomized immunodeficient recipients, there was no difference in the establishment of grafts of fresh (92%) and frozen (90%) ovaries, the number of recipients showing vaginal cornification (fresh, 91%, frozen 96%) or the latency of cornification (11 days). Fifteen days after transplantation, similar numbers of follicles remained in grafts of fresh ovaries, in ovaries frozen in dimethylsulfoxide and 1,2-propanediol, and in ovaries frozen after exposure to ethanediol for 5-30 min. Overall, the total number of follicles remaining in grafts of ovaries frozen in dimethylsulfoxide and 1,2-propanediol represented 42-46% of follicles present in ungrafted ovaries. This was not significantly different from grafts of fresh ovaries (63%). Dimethylsulfoxide and 1,2-propanediol are the most effective cryoprotectants for 10-day-old mouse ovaries. The majority of follicles are lost during graft establishment.

Calibration of a portable tritium-in-air monitor for various radioactive gases

A commercially available portable tritium-in-air monitor was calibrated for detecting the concentration of tritium-in-air, 14C-in-air, and various radioactive noble gases. Calibrations were performed both experimentally, using assayed quantities of the calibration gases, and theoretically, by simulating the monitor's response using Monte Carlo code. The experimental and theoretical calibrations agreed within +/- 10% for all gases tested with the exception of 41Ar-in-air where the agreement was approximately 20%. The results show that, although the monitor can be used to measure a wide range of radioactive gases, if more than one gas is present the monitor can not be used to accurately determine the concentration of, and hazard posed by, these gases. It is also shown that the monitor's ability to accurately assess tritium-in-air hazards would be seriously compromised by the presence of other radioactive gases.

Immune responses to adenoviral vectors during gene transfer in the brain

We have investigated the immune response to E1-deleted adenovirus vectors encoding the lacZ gene introduced into the brains of adult mice. Injection of these nonreplicating vectors caused a marked inflammatory response in the brain as assessed by immunocytochemistry and flow cytometry of leukocytes. Infiltrating leukocytes were detectable within 2 days of injection and reached a maximum by 9 days. Thereafter, the number of infiltrating cells decreased, but a small number persisted in the brain until day 60. Between 2 and 4 days after injection, the percentage of CD8+ cells detectable increased whereas the percentage of CD4+ cells present in the infiltrating population did not significantly increase until day 6, peaking on day 15. Activated CD25+ T cells were detectable between days 6 and 15. beta-Galactosidase (beta-Gal), the product of the lacZ gene encoded by the vector, was also detected, both at the injection site in the striatum and also in the substantia nigra. Expression peaked between 4 and 6 days but a small number of beta-Gal+ cells was still seen at 60 days after injection. This study demonstrates that a quantitative analysis of the immune responses caused by a nonreplicating adenovirus vector is possible in the brain. E1-deleted adenoviral vectors trigger a strong inflammatory response in the brain, but this immune response is not sufficient to eliminate completely expression of genes encoded by the adenoviral construct.

Immune responses to adenovirus vectors in the nervous system

Non-replicating adenovirus vectors are being developed as vehicles for gene transfer into cells of the nervous system. An important requirement for successful gene transfer is the absence of deleterious cytotoxic or inflammatory side effects of the delivery system. Despite offering relatively stable reporter gene expression, currently available adenovirus vectors also elicit immune responses in the brain, both at the site of vector delivery and at synaptically linked distant sites. However, although an anti-viral T-lymphocyte response eliminates the vector and damages local tissue in many peripheral organs, the immune response to adenovirus in the brain is less effective and enables the vector to persist. Nevertheless, in this persistent state the adenovirus vector remains a potential target for a destructive immune response that can also cause local demyelination. The development of strategies to minimize this damaging immune response, through either vector modification or immunomodulation, will be crucial for the future success of genetic therapies in the brain.

Role of T cells in inflammation caused by adenovirus vectors in the brain

In many organs, E1-deleted human adenovirus vectors trigger antiviral T cell responses which limit the duration of vector-encoded gene expression. When injected into the brain, however, long-term expression is possible in spite of the ensuing inflammatory response. To examine the role of T cells in the immune response in the brain, monoclonal antibodies were used to systemically deplete CD4+ and/or CD8+ T cell subsets from mice at the time of vector injection. The early phase of the inflammatory response, characterized by high MHC I expression and recruitment of mononuclear cells, was unaffected by T cell depletion. Six days after injection, however, inflammation was markedly reduced by CD8-depletion and eliminated by CD4-depletion. Vector expression of the marker protein beta-galactosidase did not differ between depleted and undepleted mice. In contrast, when mice had been previously exposed to adenovirus vector in the periphery, beta-galactosidase expression in the brain was transient, showing that T cells can effectively target vector-transduced cells in this organ. We conclude that adenovirus vectors are able to achieve long-term expression in the brain because such a route of injection triggers an ineffective T cell response.

The clinical pharmacokinetics of famciclovir

Famciclovir is an oral prodrug of the antiherpesvirus nucleoside analogue, penciclovir. Following oral administration famciclovir undergoes extensive first pass metabolism to penciclovir and essentially no parent compound is recovered from plasma or urine. Penciclovir plasma concentrations reach a maximum less than 1 hour after famciclovir administration in fasting individuals, but are delayed if famciclovir is taken within 2 hours of a meal. The bioavailability of penciclovir, measured by urinary recovery, is approximately 60% and is not affected by food. Over the likely therapeutic dose range of famciclovir 125 mg to 750 mg, the pharmacokinetics of penciclovir are linear. The volume of distribution of penciclovir after intravenous administration is more than 1 L/kg, indicating extensive distribution into the tissue. Penciclovir is predominantly eliminated unchanged by the kidney, partly by active tubular excretion and has a terminal phase elimination half-life (t1/2 beta) of between 2 and 2.5 hours and a renal clearance (CLR) of between 25 and 30 L/h in individuals with normal renal function. In those with severe renal impairment the CLR falls markedly and the t1/2 beta increases to over 18 hours. Haemodialysis appears to be effective in clearing penciclovir from plasma. Elderly individuals tolerate famciclovir well, despite slower elimination secondary to age-related lower renal clearance. Uncomplicated herpes zoster does not affect the pharmacokinetic profile of penciclovir. In the limited studies undertaken so far, no significant drug interactions have been demonstrated.

Antivirals in the context of HIV disease

Antiviral drugs, other than those with anti-retroviral activity, are used in persons with human immunodeficiency virus (HIV) infection for two purposes: treatment or prevention of viral infections that cause disease in persons with immunodeficiency, and to suppress viruses that might act as co-factors and promote replication of HIV itself. Human herpesviruses are the major targets of therapy in both settings. The herpesviruses, particularly cytomegalovirus (CMV), herpes simplex virus (HSV) and varicella-zoster virus (VZV) act as opportunistic pathogens as cell-mediated immunity declines, and there is theorectical, in-vitro, and in-vivo evidence that one or more herpesviruses can accelerate the progression of HIV disease. Therapy and prophylaxis with antiherpes compounds such as acyclovir, ganciclovir and foscarnet are well established in HIV infection, and this article will review their present use and recent improvements in formulations and drug delivery.

Multiple dose netivudine, a potent anti-varicella zoster virus agent, in healthy elderly volunteers and patients with shingles

Netivudine is a nucleoside analogue with potent anti-varicella zoster virus activity. We now report two open studies of the pharmacokinetics and tolerability of netivudine in doses of 50, 100 and 200 mg twice daily. In one study, healthy volunteers received an initial, single dose followed, a week later, by repeat dosing for 9 1/2 days; in the other, patients with shingles were treated for 8 days and data were also recorded for rash resolution and pain duration and intensity. Netivudine was well tolerated in both studies. Plasma concentrations were similar in patients and healthy volunteers and increased in proportion to dose. Steady state concentrations were 15-25% lower than expected from single dose data, probably because of slightly decreased netivudine absorption after food. Elimination half-life was l4-20 h. Plasma concentrations of 5-propynyluracil (5-PU), the main metabolite of netivudine, did not increase in proportion to the netivudine dose and tended to be higher in patients than volunteers. 5-PU concentrations remained elevated for up to 72 h after the last netivudine dose, suggesting continued but slow release from unabsorbed netivudine in the gut lumen. New lesion formation ceased and vesicles crusted most quickly in the 200 mg group; zoster-associated pain intensity, was reduced in a dose-related manner.

Outdoor field evaluation of passive tritiated water vapor samplers at Canadian power reactor sites

Tritium is one of several radioactive nuclides routinely monitored in and around CANDU (CANada Deuterium Uranium) power reactor facilities. Over the last ten years, passive samplers have replaced active sampling devices for sampling tritiated water vapor in the workplace at many CANDU stations. The potential of passive samplers for outdoor monitoring has also been realized. This paper presents the results of a 1-y field trial carried out at all five Canadian CANDU reactor sites. The results indicate that passive samplers can be used at most sampling locations to measure tritiated water vapor in air concentrations as low as 1 Bq m-3 over a 30-d sampling period. Only in one of the five sampling locations was poor agreement observed between active and passive monitoring data. This location, however, was very windy and it is suspected that the gusty winds were the source of the discrepancies observed.

Oral acyclovir therapy accelerates pain resolution in patients with herpes zoster: a meta-analysis of placebo-controlled trials

Meta-analysis of four double-blind, randomized, placebo-controlled trials of oral acyclovir (800 mg five times daily) for the treatment of herpes zoster was conducted to provide definitive assessments of the effect of acyclovir on the resolution of zoster-associated pain. The studies involved a total of 691 patients, and the analysis was performed on an intent-to-treat basis. A range of milestones of pain cessation were evaluated by means of Cox regression models with adjustment for relevant prognostic factors. The proportion of patients with postherpetic neuralgia at 3 and 6 months was also determined. Advancing age and more severe pain at presentation were associated with more prolonged pain. Acyclovir was clearly shown to accelerate pain resolution by all of the measures employed. Benefit was especially evident in patients 50 years of age or older. Fewer acyclovir recipients had postherpetic neuralgia at 3 or 6 months. Overall, the reductions of pain duration and prevalence were approximately twofold.

The comparative efficacy and safety of teicoplanin and vancomycin

Glycopeptide antibiotics, such as teicoplanin and vancomycin, are active against staphylococci (including methicillin resistant strains), streptococci, enterococci and Clostridium spp. Vancomycin and teicoplanin are both widely used in the treatment of infections caused by Gram-positive organisms. Vancomycin can, however, provoke a number of side-effects, and serum concentrations should be monitored during treatment. Teicoplanin has a longer half-life than vancomycin, it can be given as an intravenous bolus or by intramuscular injection, and nephrotoxicity and ototoxicity are relatively uncommon. Treatment with teicoplanin might, therefore, offer advantages over treatment with vancomycin-provided that similar clinical efficacy can be shown. At least 11 clinical trials comparing the efficacy and safety of teicoplanin and vancomycin have been carried out worldwide. Meta-analysis of the combined results from these studies indicates that more than three-quarters of the patients in each of the treatment groups had a clinical response to therapy. Meta-analysis of the numbers of adverse events occurring in each treatment group shows significantly fewer reports of adverse events in patients receiving teicoplanin (13.9%) than in those receiving vancomycin (21.9%). Direct comparisons are difficult because of inherent differences between studies, but available data suggest that teicoplanin is as effective as vancomycin and that its superior tolerability together with advantages such as once-daily bolus administration, intramuscular use and lack of requirement for routine serum monitoring, give it considerable potential for use in clinical practice.

Indefinite survival of neural xenografts induced with anti-CD4 monoclonal antibodies

Xenografts of neural tissue are usually rapidly rejected when transplanted into the central nervous system of adult recipient animals. This study has examined the cell mediated immune response to both concordant (between closely related species) and discordant (between distantly related species) neural xenografts in the mouse, and has investigated the role of the CD4+ and CD8+ T lymphocyte subsets in this process using monoclonal antibodies specific for the CD4 and CD8 cell surface glycoproteins. We have established that: (1) in this model system concordant neural xenograft rejection occurs within 15-30 days; however, xenograft survival can be dramatically prolonged with CD4+, but not CD8+, T lymphocyte depletion; (2) the administration of two successive courses of a high dose of anti-CD4 monoclonal antibody treatment results in indefinite concordant neural xenograft survival; (3) the mechanism by which the high dose anti-CD4 monoclonal antibody therapy appears to function involves the depletion of intrathymic CD4+ cells; (4) anti-CD4 monoclonal antibody treatment enhances discordant neural xenograft survival, to beyond 60 days in many cases. These results demonstrate that CD4+ T lymphocytes are of central importance in the immune response to both concordant and discordant neural xenoantigens. Thus the use of anti-CD4 monoclonal antibody therapy is an effective strategy to prolong significantly the survival of xenogeneic neural transplants. Furthermore this treatment caused no obvious deleterious side-effects. These findings have implications for future cross-species studies in experimental neurobiology and, possibly, in clinical neural transplantation.

Delayed primary repair of intrathoracic esophageal perforation: is it safe?

The management of intrathoracic esophageal perforation with delayed diagnosis is a subject of controversy. Because of the obvious advantages of primary repair as a simple single-stage operation, this technique was preferentially used to treat 18 of 22 consecutive patients with esophageal perforation. These patients were stratified into three groups according to the time interval between perforation and repair: group A, less than 6 hours, five patients (28%); group B, 6 to 24 hours, six patients (33%); and group C, more than 24 hours, seven patients (39%). Group A patients were older (p < 0.05) and group B had fewer iatrogenic perforations (B, 17%; A, 80%; C, 57%, p < 0.1). Additional tissue was used to buttress the repair site in all three groups (A, 3/5 patients, 60%; B, 4/6 patients, 67%; C, 6/7 patients, 86%; p = not significant). In seven patients (39%), a fundic wrap was used to reinforce the site of primary repair. The outcomes of the three groups were analyzed. Group A had the lowest proportion of postoperative leaks (A, 0/4 patients, 0%; B, 4/6 patients, 67%; C, 5/6 patients, 83%; p < 0.05) and postoperative morbidity (A, 2/5 patients, 40%; B, 6/6 patients, 100%; C, 6/7 patients, 86%; p < 0.1). However the increased incidence of leak and morbidity did not lead to an increase in mortality. One death occurred in each group, with an overall mortality of 17% (A, 1/5 patients, 20%; B, 1/6 patients, 17%; C, 1/7 patients, 14%; p = not significant). We conclude that in the era of advanced intensive care capabilities, primary repair of intrathoracic esophageal perforation can be safely accomplished in most patients regardless of the time interval between perforation and operation. Leakage at the suture site is common unless primary repair is carried out without delay. Postoperative leakage, however, is usually inconsequential and does not necessarily result in an adverse outcome.

How should we measure pain in herpes zoster?

Pain occurs during the acute phase of herpes zoster and as postherpetic neuralgia (PHN) for months or years after the acute illness has healed. The acute pain results from viral replication leading to the death of neurons together with cutaneous inflammation. However, the exact mechanism of PHN is still conjectural. Historically, PHN has been defined as any pain that follows disappearance of the rash of herpes zoster, but a number of other definitions (eg, pain present for more than 1 or 2 months after rash onset) have also been used. Since pain is purely subjective and is usually felt as a continuum, any definition is entirely arbitrary and sheds no light upon the pathophysiology of the prolonged pain. An arbitrary division of pain poses problems for the measurement of the effect of acute therapy upon the duration of PHN. Use of a definition of PHN that involves the time of rash healing also leads to considerable difficulties in the assessment of therapies that affect the duration of the rash. The median times for resolution of both acute pain and PHN are likely to be biased in favor of therapy that heals the rash more rapidly, even if the continuum of pain is not affected. For these reasons, the term "zoster-associated pain," encompassing both the acute and chronic pain associated with herpes zoster, has evolved as a more meaningful way of measuring pain both for the individual patient and also for the comparison of two potential therapies.

Stability of vancomycin in plastic syringes measured by high-performance liquid chromatography

The shelf-life of vancomycin in infusion fluids was studied using high-performance liquid chromatographic (HPLC) methods. Vancomycin was stable (loss in potency less than 10%) for 47 days and 29 days, respectively, when dissolved in water-for-injections BP at 25 degrees C and stored in plastic syringes (Becton Dickinson Plastipak (three-piece) and B. Braun Medical Injekt (two-piece)). In sodium chloride solution (0.9%; pH 5.4) it was stable for 62 and 34 days, while in dextrose solution (5%; pH 4.2) it was stable for 55 and 33 days, respectively, at the same temperature. At 4 degrees C vancomycin was stable in all three infusion fluids and both types of syringe for at least 84 days.

How should zoster trials be conducted?

In 1994, an international group of interested clinicians and biostatisticians met to discuss the design of clinical trials in herpes zoster. They agreed that trials in herpes zoster should have prospectively agreed definitions of all outcome measures and plans for data analysis. In immunocompetent individuals, in whom pain is the major outcome measure, trials should only include patients over the age of 50 years, and for those recruited within 72 h of rash onset, should be designed to demonstrate superiority of any new therapy over existing antivirals. The primary endpoint should be time to cessation of pain for at least 4 weeks and, for the purposes of statistical analysis of its duration, the pain associated with herpes zoster ought to be considered as a continuum. All other variables, including the incidence of post-herpetic neuralgia and effects upon quality of life should be considered as secondary end-points. Evaluation of treatment effects on primary endpoints should be based upon an intent-to-treat (ITT) analysis and subgroup analysis should be used only to support the findings of the ITT analysis. These elements of good study design should be borne in mind in the evaluation of current and future trails of antiviral drugs in herpes zoster.

Cytogenetical analysis and developmental potential of vitrified mouse oocytes

Mature mouse oocytes were cryopreserved by vitrification in 6 M dimethyl sulfoxide (VS). After warming they were either artificially activated with strontium (Sr2+), and the incidence of chromosome non-disjunction was assessed at first cleavage metaphase; or they were fertilized in vitro, and postimplantation survival was examined at Day 15 of gestation. Similar proportions of vitrified and freshly collected oocytes were activated with Sr2+ (75% and 82%, respectively). The majority of activated oocytes extruded the second polar body and formed a single pronucleus ( > 90%). When the exposure time to VS was increased from 90 to 110 sec without cooling, a significant proportion of activated oocytes arrested at the pronuclear stage (30%), and chromosome condensation did not occur. The frequency of aneuploidy in vitrified and control oocytes was similar, but when exposure to VS without cooling was extended, aneuploidy and second polar body retention were significantly higher than those of controls (p < 0.05). The rates of fertilization of vitrified (85%) and control oocytes (92%) did not differ. After transfer, similar proportions of vitrified and control embryos implanted (68-80%) and formed normal fetuses (38-49%). We conclude that vitrification in 6 M dimethyl sulfoxide is a simple and safe procedure for the preservation of mouse oocytes provided that the time of exposure to the cryoprotectant is carefully controlled.

Follicular development in cryopreserved marmoset ovarian tissue after transplantation

Pieces of marmoset ovary were frozen by slow cooling in 1.5 M dimethylsulphoxide. The follicles in fresh and frozen tissue were counted and examined for morphological appearance in stained serial sections. The proportion of normal follicles was similar in fresh tissue and frozen tissue examined immediately after thawing. Follicles at all stages of folliculogenesis up to the small antral stage survived freezing and thawing. Fresh and frozen tissue was transplanted underneath the kidney capsules of ovariectomized immunodeficient mice. The establishment of grafts was similar, and oestrogenic activity (cornification of the vaginal epithelium) was observed in the recipients 20 and 16 days after transplantation of fresh and frozen grafts respectively. The total number of follicles and the proportion of normal follicles were similar in fresh and frozen grafts. Grafts of frozen tissue recovered between 7 and 15 days after transfer contained follicles up to the small antral stage of development. Grafts recovered between 21 and 32 days contained follicles at all stages of folliculogenesis, including large antral follicles (1-2 mm diameter). Our results suggest that freezing and thawing do not substantially damage marmoset ovarian tissue, and the cryopreserved tissue retains its ability to support the development of large antral follicles.

Cannabinoids in humans. II. The influence of three methods of hydrolysis on the concentration of THC and two metabolites in urine

Glucuronide conjugates of cannabinoids were previously identified in humans. For gas chromatographic-mass spectrometric (GC-MS) analysis of the unconjugated compounds in human urine, it is necessary to cleave the glucuronide moiety. Base hydrolysis and two forms of enzymatic hydrolysis were compared in this study to examine any quantitative differences between the hydrolysis methods. Human volunteers (n = 8) each smoked one marijuana cigarette containing 3.58% delta 9-tetrahydrocannabinol (THC) and submitted urine samples prior to smoking, 5 min after smoking, and hourly for 8 h thereafter. Urine (1 mL) was buffered to the optimum pH for each form of enzyme tested. beta-Glucuronidase from Escherichia coli (bacteria) or Helix pomatia (mollusk) was added to the specimens, followed by overnight incubation at 37 degrees C. Following hydrolysis, the samples were extracted using hexane-ethyl acetate (7:1) and derivatized with N,O-bis(trimethylsilyl)-trifluoroacetamide plus 1% trimethylchlorosilane, which converted the cannabinoids to their trimethylsilyl derivatives. GC-MS analysis revealed striking differences between the hydrolysis methods. Concentrations of unconjugated THC and 11-hydroxy-THC (11-OH-THC) using E. coli were significantly increased over all other methods tested (p < .05). These results demonstrate the species-dependent nature of glucuronidase activity in hydrolyzing THC and 11-OH-THC glucuronides and the ineffectiveness of base hydrolysis on these hydroxylated compounds. The need for further study to find the optimum conditions necessary for the complete hydrolysis of cannabinoid conjugates is suggested.

Valaciclovir compared with acyclovir for improved therapy for herpes zoster in immunocompetent adults

Acyclovir treatment of acute herpes zoster speeds rash healing and decreases pain and ocular complications. The limited oral bioavailability of acyclovir necessitates frequent dosing. Valaciclovir, the l-valyl ester of acyclovir, is rapidly and almost completely converted to acyclovir in vivo and gives three- to fivefold increases in acyclovir bioavailability. In a randomized, double-blind, multicenter study, the safety and efficacy of oral valaciclovir given at a dosage of 1,000 mg three times daily for 7 or 14 days and oral acyclovir given at a dosage of 800 mg five times daily for 7 days were compared in immunocompetent adults aged > or = 50 years with herpes zoster. Patients were evaluated for 6 months. The intent-to-treat analysis (1,141 patients) showed that valaciclovir for 7 or 14 days significantly accelerated the resolution of herpes zoster-associated pain (P = 0.001 and P = 0.03, respectively) compared with acyclovir; median pain durations were 38 and 44 days, respectively, versus 51 days for acyclovir. Treatment with valaciclovir also significantly reduced the duration of postherpetic neuralgia and decreased the proportion of patients with pain persisting for 6 months (19.3 versus 25.7%). However, there were no differences between treatments in pain intensity or quality-of-life measures. Cutaneous manifestations resolved at similar rates in all groups. Adverse events were similar in nature and prevalence among groups, and no clinically important changes occurred in hematology or clinical chemistry parameters. Thus, in the management of immunocompetent patients > or = 50 years of age with localized herpes zoster, valaciclovir given at 1,000 mg three times daily for 7 days accelerates the resolution of pain and offers simpler dosing, while it maintains the favorable safety profile of acyclovir.

Adenovirus gene transfer causes inflammation in the brain

We report that injecting an E1-deleted, non-replicating, human adenovirus type 5 vector into the brain leads to an inflammatory response. Much of this inflammation is induced directly by the virion particles themselves rather than through the expression of new proteins from the vector. The severity of inflammation was found to depend on the strain of inbred rat used: PVG rats have less inflammation than AO rats in response to a vector injection. Twelve hours after injection of adenovirus vectors into the striatum of AO rats, leukocytes were seen marginating to the walls of nearby blood vessels. By two days there was a large increase in major histocompatibility complex class I expression and a heavy infiltration of leukocytes, mainly macrophages and T cells. Retrograde transport of adenovirus to neurons of the substantia nigra was associated with a delayed and less intense inflammation at this distant site. Although AO and PVG rats showed comparable responses in the striatum up to six days, at later times PVG rats had less intense inflammation. In spite of the inflammatory response, vector-driven expression of the marker protein beta-galactosidase and an adenovirus early protein was seen for at least two months following the injection, although expression declined with time. The observation that adenovirus gene transfer leads to an inflammatory response in the brain must be taken into account when planning and interpreting experiments with these vectors. Furthermore, we conclude that using an appropriate strain of rat can diminish some aspects of the inflammation.

Screening bone scintigraphy in the staging of locally advanced head and neck cancer

A retrospective determination of the yield from screening bone scintigraphy in detecting bone metastasis when used for disease staging of 93 asymptomatic patients with locally extensive head and neck cancer was undertaken. The bone scintigraphy findings were correlated with observations from other radioimaging studies done within 1 month of head and neck cancer diagnosis. Bone scintigraphy did not reveal a single case of bone metastasis outside the head and neck region. On the other hand, 3 cases (8%) of resectable and 2 cases (5%) of non-resectable bone metastasis located within the head and neck area were observed among the 40 patients with abnormal bone scintigraphy. Old rib fracture or degenerative disease was responsible for the increased radionuclide uptake in bony areas below the clavicle in less than half of the remaining 35 cases. We conclude that the routine use of bone scintigraphy for disease staging in asymptomatic patients with locally advanced head and neck cancer is not warranted because the positive yield is low.

Bone mineral density of the total body and forearm in premenopausal black and white women

This study was conducted to report and compare bone mineral density (BMD) of the total body and distal forearm, as measured by X-ray absorptiometry, in 65 black and 73 white premenopausal women between the ages of 20 and 40. The black women had higher current and recalled body weights, a higher percent body fat, and more pregnancies and births, were younger at menarche, and reported lower alcohol intakes than the white women studied. A smaller percent of the black women had experienced amenorrhea, and a higher percent had lived at southern latitudes. Smoking history and lifetime use of oral contraceptives were similar in the two groups. Total body BMD, adjusted for body mass index (BMI), was 5.9% higher in the black than in the white women [mean +/- standard deviation (SD): 1.230 +/- 0.076 g/cm2 compared with 1.161 +/- 0.075; difference (95% confidence interval [CI95]: 0.068 (0.042, 0.095)]. Forearm BMD, adjusted for BMI, was 9.3% higher in the black women [mean +/- SD: 0.505 +/- 0.046 compared with 0.462 +/- 0.045; difference (CI95): 0.043 (0.027, 0.059)]. Adjustment for the other medical and lifestyle differences noted before had little effect on estimated BMD differences between the two groups.

Specific patterns of defective HSV-1 gene transfer in the adult central nervous system: implications for gene targeting

Viral vectors are a means by which genes can be delivered to specific sites in the adult central nervous system. Nevertheless, the interaction between the viral vector and cells of the nervous system, which forms the basis for specific gene transfer, is not well understood. In this study a nonreplicating defective herpes simplex virus type 1 vector, expressing the marker gene lacZ, was stereotaxically injected at varying titers into the rat central nervous system. Three sites were targeted: the caudate nucleus, dentate gyrus, and cerebellar cortex, and the resulting patterns of beta-galactosidase activity were examined. Many cells of neuronal and glial morphology, and of differing neuronal subtypes, expressed beta-galactosidase at each of the injection sites. However, beta-galactosidase activity was also detected in distant secondary brain areas, the neurons of which make afferent connections with the primary sites. This strongly suggested that the retrograde transport of defective virus was the basis for the enzyme activity observed at a distance. Moreover, retrograde transport to secondary sites was found to be highly selective and restricted to certain retrograde neuroanatomical pathways in a specific and titer dependent fashion. The pathways observed were predominantly, but not exclusively, monoaminergic in origin. This finding is supported by reports of specific tropism by HSV for monoaminergic circuits in experimental encephalitis and transneuronal tracing studies. Our observations suggest that certain functional neuronal populations, which are permissive for the retrograde transfer of defective HSV-1 vectors, might be specifically targeted for gene transfer using this approach. Conversely, a knowledge of the pathways permissive for viral uptake, retrograde transfer, and subsequent gene expression will be essential in order to predict the consequences of gene transfer using viral vectors.

Cryopreservation of immature mouse oocytes

Mouse oocytes enclosed in cumulus cells were isolated from antral follicles at the germinal vesicle (GV) stage. They were stored in straws at -196 degrees C by a conventional mouse embryo freezing method using dimethylsulphoxide (1.5 M) as the cryoprotectant. Overall survival assessed after removal of the cumulus cells was 93% (299/320). A significantly greater proportion of fresh oocytes remained arrested at the GV stage during culture (11 versus 1%), but the rate of maturation to metaphase II was not significantly different between frozen and fresh oocytes (83 versus 74%). The rate of fertilization in vitro was similar for frozen and fresh oocytes matured in vitro (70 versus 81%) but significantly less than with mature ovulated oocytes (96%). Fertilization of frozen and fresh oocytes arrested after germinal vesicle breakdown was similar (77 versus 95%). No evidence of parthenogenetic activation was found in the different groups after overnight incubation of metaphase II oocytes. Implantation was similar for embryos derived from fresh and frozen GV-stage oocytes matured in vitro and mature ovulated oocytes, but the loss of embryos after implantation was significantly higher in the in-vitro matured groups (frozen, 40% and fresh, 46% versus 24%). The overall survival of oocytes frozen at the GV stage was 27%. This compares favourably with the estimated overall survival of mature oocytes cryopreserved by a similar procedure. We conclude that the increased post-implantation loss is due to suboptimal conditions for maturation in vitro rather than freezing injury.

Inflammatory effects of gene transfer into the CNS with defective HSV-1 vectors

The use of viral vectors which infect and express genes in post-mitotic neurons is a potential strategy for the treatment of disorders affecting the central nervous system (CNS). However, the inflammatory consequences of such strategies have yet to be systematically examined. Preparations of non-replicating defective herpes simplex virus type 1 (HSV-1) amplicon vectors containing the lacZ gene were obtained by standard methods and stereotaxically injected into the adult rat dentate gyrus (DG). The consequent gene expression and inflammatory effects following microinjection were investigated. beta-Galactosidase activity was detected in neurons of the DG from 24 h to at least 12 days after vector injection. A strong inflammatory response developed within 2 days, characterized by diffuse up-regulation of major histocompatibility complex (MHC) class I antigens and the activation of microglia. After 4 days the recruitment of MHC class II+ cells, activated T lymphocytes and macrophages was detected. These features persisted for at least 31 days. Of importance was the finding of beta-galactosidase activity in a bilateral group of neurons in the supramammillary nuclei (SMN) of the posterior hypothalamus, known to send afferent projections to the DG. The onset of inflammation at this secondary site was delayed, but its cellular characteristics resembled those found at the primary site of injection. Thus, the use of preparations of defective HSV-1 vectors for gene transfer in the CNS has immunological implications both at primary and secondary sites within the CNS.(ABSTRACT TRUNCATED AT 250 WORDS)

High in vitro and in vivo survival of day 3 mouse embryos vitrified or frozen in a non-toxic solution of glycerol and albumin

A vitrification solution consisting of 6.5 mol glycerol l-1 and 6% (w/v) BSA in a modified Dulbecco's PBS (designated solution VS3a) was examined for the cryopreservation of 8-12-cell mouse embryos. Solution VS3a vitrified when cooled to -196 degrees C at rates of 10-2500 degrees C min-1 and vitrified suspensions did not crystallize when warmed at 200 or 2000 degrees C min-1. However, slow cooling at 5 degrees C min-1 or slow warming at 20 degrees C min-1 resulted in visible crystallization of solution VS3a. Embryos were equilibrated in solution VS3a in three steps at room temperature and placed into a 0.25 ml plastic straw in a way that permitted in-straw dilution with 1 mol sucrose l-1. Embryos equilibrated in solution VS3a and diluted immediately exhibited high rates of development in vitro to blastocysts (> 90%) if the total time of exposure to 100% solution VS3a did not exceed 5 min. Embryos exhibited high rates of development in vitro (75-97%) when equilibrated in 100% solution VS3a for 1 min and then cryopreserved using all combinations of three rates of cooling (5200 or 2500 degrees C min-1) and three rates of warming (20,000 or 2000 degrees C min-1). Although embryo suspensions visibly crystallized during slow cooling at 5 degrees C min-1, the rate of cooling was not a significant source of variance (P > 0.26). However, the rate of warming was found to have a small but significant effect on embryo survival (P < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of motion sickness and antimotion sickness drugs on gastric function

This study examined the effects of motion sickness and antimotion sickness drugs on gastric emptying (GE). Drugs were tested in normal and motion sick subjects. To induce motion sickness, subjects performed head movements while seated in a rotating chair. Gastric emptying of liquid (300 mL) was determined by nuclear medicine techniques, whereas gastric electrical activity, the electrogastrogram (EGG), was monitored from surface (cutaneous) electrodes positioned over the abdominal area. Gastric emptying was severely inhibited at the peak of motion sickness symptoms, but returned to normal 15 minutes later when symptoms abated. In normal (non-motion sick) subjects intramuscular (IM) scopolamine (0.1 mg) and IM promethazine (25 mg) inhibited GE, whereas erythromycin ethylsuccinate (EES) suspension (200 mg) given orally increased GE. When administered to motion sick subjects, IM scopolamine and IM promethazine added slightly, but not significantly, to the inhibition of GE already present. Oral EES did not significantly alter GE in motion sick subjects. Although EGG frequency remained within normal limits (approximately 2.5-3.5 cpm) after liquid ingestion in both normal and motion sick subjects, EGG amplitude was differentially affected in the two groups. Electrogastrogram amplitude increased twofold to fourfold after liquid ingestion in normal, but not in motion sick subjects. The results suggest that (1) maximal inhibition of GE is coincident with peak motion sickness symptoms, (2) both IM scopolamine and IM promethazine inhibit GE in normal subjects, but do not add significantly to the inhibition of GE already established during motion sickness, (3) orally administered erythromycin enhances GE in normal, but not in motion sickness subjects, and (4) the normal stimulatory effect of liquid ingestion on gastric motility does not occur in motion sick subjects.(ABSTRACT TRUNCATED AT 250 WORDS)

Habituation and motion sickness

The vestibular, cerebellar, and reticular systems are central in importance, in motion sickness and habituation, to the effects of motion. Nuclear medicine single photon emission computed tomography (SPECT) studies of cerebral blood flow and power spectral electroencephalographic recordings during motion sickness were used to determine alterations in the central nervous system. The rotating chair with and without visual stimulation was used to study the rate of habituation and the effect of antimotion sickness medications on this rate. An increase of theta waves over the frontal cortex indicated a decreased activation of the higher centers during motion sickness. Motion sickness also produces an increase of blood flow in the central cerebellum that has connections to the reticular system. This increase in cerebellar activity is relayed to the reticular system whereby neural recruitment builds up to trigger the vomiting center, producing motion sickness. Habituation may be a conditioned compensatory activation of the reticular neurons that prevents this disruption of normal activation. The rate of habituation when motion sickness was prevented by scopolamine was slowed, indicating that, if the central nervous system is not challenged by disruption of normal activation, it does not produce the compensatory reactions that result in habituation.

Current experience with antiviral therapy for acute herpes zoster

Inhibition of varicella-zoster virus replication during acute herpes zoster would, theoretically, accelerate cutaneous healing and reduce the pain, both acute and chronic, associated with shingles. Early antiviral drugs were of limited efficacy, excessively toxic, or needed to be given parenterally, and were unsuitable for use in immunocompetent individuals. Acyclovir was a significant advance and remains the antiviral drug of choice for herpes zoster. There is ample evidence for its efficacy in acute illness, but its ability to influence post-herpetic neuralgia is controversial. This review also discusses the role of adjunctive therapy with steroids in acute shingles.

A randomized trial of acyclovir for 7 days or 21 days with and without prednisolone for treatment of acute herpes zoster

BACKGROUND

Acyclovir given for 7 to 10 days is of proved benefit in acute herpes zoster, but studies of its effectiveness in preventing postherpetic neuralgia have had conflicting results. The role of corticosteroids in the treatment of herpes zoster is also controversial.

METHODS

We conducted a double-blind, controlled trial in patients with acute herpes zoster to determine whether either 21 days of acyclovir therapy or the addition of prednisolone offered any improvement over 7 days of acyclovir therapy. Patients with a rash of less than 72 hours' duration were assigned to receive acyclovir (800 mg orally, five times daily) for 7 days with either prednisolone or placebo, or acyclovir for 21 days with either prednisolone or placebo. Prednisolone therapy was initiated at a dose of 40 mg per day and tapered over a three-week period. Patients were assessed frequently through day 28 and then monthly through month 6 to assess postherpetic neuralgia.

RESULTS

Of 400 patients recruited, 349 completed the study. No significant differences were detected between the four groups in the progression of the rash (P > 0.1). With steroid therapy, a significantly higher proportion of the rash area had healed on days 7 and 14 (P = 0.02). Pain reduction was greater during the acute phase of disease in patients treated with steroids or 21 days of acyclovir (P < 0.01 and P = 0.02, respectively, on day 7; P < 0.01 for steroid therapy on day 14). However, on follow-up there were no significant differences between any of the groups in the time to a first or a complete cessation of pain. The steroid recipients reported more adverse events.

CONCLUSIONS

In acute herpes zoster, treatment with acyclovir for 21 days or the addition of prednisolone to acyclovir therapy confers only slight benefits over standard 7-day treatment with acyclovir. Neither additional treatment reduces the frequency of postherpetic neuralgia.

Morphological assessment of grafted rat and mouse cortical neurons: a light and electron microscopic study

The morphology of cortical neurons grafted into (or near) the rat striatum was studied by means of intracellular Lucifer yellow injections in fixed slices. Rat donor syngeneic cortical tissue (from postnatal day 1 old rats; AO strain) as well as mouse donor xenogeneic cortical tissue (prenatal day 19; C3H/HE strain) were grafted as solid pieces into 8-12 week-old rats (AO strain). Recipients of mouse xenografts were immunosuppressed with a monoclonal antibody against the interleukin-2 receptor. After perfusion and sectioning of the graft-containing areas, individual slices were incubated in the DNA stain 4.6-diamidino-2-phenylindole (DAPI) to visualize the cell nuclei. Grafts could be easily identified by a surrounding rim of astrocytes which outline the border between grafted and host tissue. Grafted cortical neurons were intracellularly filled with Lucifer yellow, DAB-photoconverted, and further processed for light and electron microscopy. In general, no cortical lamination could be observed in the grafted rat and mouse cortical tissue, but neurons were loosely packed throughout the graft. Two major cell types could be identified in all grafts investigated so far. The majority resembled those described as spiny neurons (85%), which could be further classified into pyramid-like, spiny stellate-like or fusiform spiny neurons, with somata ranging between 15 and 25 microns in diameter. The remaining 15% resembled non-spiny neurons with either a multipolar basket-like or fusiform morphology. Dendrites of spiny and non-spiny neurons, which could extend to distances up to 400 microns, were never seen to cross the astrocytic border, but some main axon and axonal collaterals of spiny neurons were found to leave the graft. On the basis of light microscopic observations no difference was found between mouse and rat grafted cortical neurons. The results of this study show that grafted cortical neurons retain some of the characteristic features of neurons in the intact adult cerebral cortex, although there appears to be a greater preponderance of spiny neurons in grafted tissue. This may reflect an immaturity of the grafted tissue or a response to the striatal environment.

Tritium sampling and measurement

Current methods for sampling and measuring tritium are described. Although the basic techniques have not changed significantly over the last 10 y, there have been several notable improvements in tritium measurement instrumentation. The design and quality of commercial ion-chamber-based and gas-flow-proportional-counter-based tritium monitors for tritium-in-air have improved, an indirect result of fusion-related research in the 1980s. For tritium-in-water analysis, commercial low-level liquid scintillation spectrometers capable of detecting tritium-in-water concentrations as low as 0.65 Bq L-1 for counting times of 500 min are available. The most sensitive method for tritium-in-water analysis is still 3He mass spectrometry. Concentrations as low as 0.35 mBq L-1 can be detected with current equipment. Passive tritium-oxide-in-air samplers are now being used for workplace monitoring and even in some environmental sampling applications. The reliability, convenience, and low cost of passive tritium-oxide-in-air samplers make them attractive options for many monitoring applications. Airflow proportional counters currently under development look promising for measuring tritium-in-air in the presence of high gamma and/or noble gas backgrounds. However, these detectors are currently limited by their poor performance in humidities over 30%.

Toxic megacolon: the knee-elbow position relieves bowel distension

Toxic megacolon complicating inflammatory or infective colitis carries a high morbidity and mortality and surgical intervention is necessary in up to 80% of cases. Perforation complicates toxic megacolon in about 35% of cases. After perforation, the death rate nears 50%. Gaseous distension of the bowel causes considerable discomfort to the patient and increases transmural pressure. The latter is thought to cause a reduction in blood flow and may predispose to perforation. The use of instruments for colonic aspiration is discouraged, because of the high risk of perforation. The successful use of the knee-elbow position to relieve bowel distension in two patients with toxic megacolon is described.

Evaluation of electret ion chamber for tritium measurement

Commercial E-PERM radon-in-air monitors modified to detect tritium in air have been evaluated. Each monitor consists of a small ion chamber with access holes around the sides to allow the air to diffuse into the chamber, and an electret at the bottom to establish an electrostatic potential. Radioactive gas inside the volume generates ions, which are collected by the electret. The reduction of charge (and subsequent reduction in surface potential) on the electret is a measure of the integrated exposure. Two types of detectors, a 50 cm3 model and a 200 cm3 model, were tested for tritium-in-air concentrations from 1 to 60 MBq m-3, and gamma-absorbed dose rates from background levels to 50 microGy h-1. The HTO-in-air response of the modified E-PERM monitors was 3.3 +/- 0.3 V MBq-1 m3 h-1 for the 200 cm3 and 0.8 +/- 0.2 V MBq-1 m3 h-1 for the 50 cm3 monitor. For external gamma radiation (226Ra), the 200 cm3 chamber gave a response of 7.6 +/- 1.8 V microGy-1 and the 20 cm3 chamber 1.8 +/- 0.5 V microGy-1. The detection limit was about 3.6 and 15.2 MBq m-3 h for the 200 and 50 cm3 chambers, respectively. The accuracy and limit of detection of the electret detectors are limited by the accuracy in measuring the surface potential on the electret.

Herpesvirus infections in childhood: 2

Infections due to herpesviruses have received increasing attention over the past decade, culminating in the isolation in 1986 of human herpesvirus-6. This is the second of two articles in which we examine the clinical spectrum of acquired herpesvirus infections in children and review developments in our understanding of the molecular biology, pathogenesis, treatment and prevention of these infections.

Herpesvirus infections in childhood: 1

Infections due to herpesviruses have received increasing attention over the past decade, culminating in the isolation in 1986 of human herpesvirus 6. We examine the clinical spectrum of acquired herpesvirus infections in children and review developments in our understanding of their molecular biology, pathogenesis, treatment and prevention.

High rates of survival and fertilization of mouse and hamster oocytes after vitrification in dimethylsulphoxide

A high proportion (> 70%) of mouse and hamster oocytes exposed for 3-5 min to 1.5 M dimethylsulfoxide (DMSO) and washed briefly in 3.9 M DMSO before vitrification in 6.0 M DMSO appeared morphologically normal on recovery. Significantly fewer (< 46%) mouse oocytes appeared normal when the time of exposure to 1.5 M DMSO was reduced to 1 min or less. The rate of fertilization in vitro of vitrified oocytes was reduced compared to the rate for untreated controls (mouse: 79% vs. 94%; hamster: 73% vs. 87%). After removal of the zona pellucida, fertilization was similar in vitrified and control hamster oocytes inseminated with hamster (> 90%) or human (21% vs. 23%) sperm. Sperm nuclear decondensation and pronuclear formation appeared to be delayed in the cytoplasm of vitrified hamster oocytes. Seventy-nine percent of 2-cell-stage mouse embryos derived from vitrified oocytes implanted after transfer to pseudopregnant recipients, but only 40% developed to normal fetuses compared to 61% of controls. The reason for this high rate of postimplantation loss is unknown.

Toward a definition of a successful dieter

The purpose of the research was to examine the characteristics of successful weight losers and to compare the findings with a control group of unsuccessful weight losers. The project was designed around a definition of successful dieters, based on the Metropolitan Life Insurance weight tables. The definition, in fact, was not particularly useful. This article describes the difficulties associated with using the original definition as the inclusion criteria for sample selection, the reanalysis of data using the Body Mass Index (BMI), and finally, the creation of a new definition developed from the construction of weight history based on changes in the BMI as an adult. This article presents the final outcome of what a definition of a successful dieter should consist in future research.

Cytokines and peripheral tolerance to alloantigen

The induction of peripheral tolerance to alloantigen is accompanied in many cases by a decrease in the production of cytokines such as IL-2 and IFN gamma, yet a sustained production of cytokines such as IL-10 and IL-4. Whether or not this altered pattern of cytokine production in tolerant animals is causally related to the induction and/or maintenance of the tolerant state has yet to be fully determined, although experiments blocking selectively the action of IL-2 with CD25 antibodies suggest that manipulation of cytokine production may at least be a route to tolerance. Alternative methods for directly influencing the cytokine balance are sought and recent experiments on the CD28/CTLA-4-B7 interaction suggest a possible approach.

Strategic market analysis: an effective tool for collaboration

If collaboration, not unrestrained competition, is part of the answer to containing health care costs, providers must choose their partners carefully. Competition won't disappear. It's here to stay. But many in our industry have come to the conclusion that increased collaboration is necessary to preserve community health care resources and prevent wasteful duplication of services and technology. Managed competition--a combination of government regulation and free markets--means simply that collaboration and competition will coexist in a new health care environment evolving toward integrated delivery systems of varying kinds.