Measles antibody seroprevalence rates among immunized Inuit, Innu and Caucasian subjects

Measles antibody seroprevalence was compared in Innu, Inuit, and Caucasian peoples of northern Newfoundland, Canada, who were immunized with a single dose of M-M-R-II (Merck Research Laboratories) vaccine. Healthy, volunteer schoolchildren (n = 606) were enrolled. Measles antibody was measured with a whole virus measles-specific IgG EIA. Native (Innu and Inuit) schoolchildren (n = 253) had a significantly higher seropositive rate (83%) after a single dose of measles vaccine compared to Caucasian (n = 353) children (76%; p = 0.025), and higher mean antibody levels after immunization compared to Caucasian children (1.74 EIA units, vs. 1.63; p = 0.06). Caucasian children were more likely to have been immunized after age 15 months (20.6% vs. 9.6%; p = 0.001). There was no significant difference in the mean time interval between immunization and blood sampling for natives versus Caucasian (8.0 years vs. 7.95 years; p = 0.49). After adjustment for time from immunization and age at immunization, there remained a marginally significant racial difference in seropositivity (OR = 1.65, 95% CI 0.96, 2.83, p = 0.068). The unadjusted odds ratio for seropositivity (comparing natives vs. non-natives, combining negative and equivocal results) was 1.66 (95% CI 1.06-2.59, p = 0.018). The higher measles-seropositive rate found among native compared to non-native Canadian children suggests that genetic and/or environmental factor(s) affect circulating antibody levels following immunization. The determination of these sources of variability may lead to the development of more efficacious vaccines or delivery strategies.

The middle cardiac vein--a novel pathway to reduce the defibrillation threshold

Defibrillation energy requirements of epicardial implantable cardioverter defibrillator systems are generally lower than endovascular systems currently used. The former has the disadvantage of requiring a thoracotomy and so has a greater morbidity and mortality than an endovascular procedure. The middle cardiac vein (MCV) is an epicardial structure that is accessible by a non-thoracotomy approach. This study investigated the merits of ventricular defibrillation from the middle cardiac vein. METHODS AND RESULTS. Defibrillation thresholds (DFT) were measured in 10 anesthetized pigs, weighing 34.5 +/- 44.1 kg (mean 39 kg). An Angeflex electrode (1.7 mm x 50 mm) was introduced via the left external jugular vein to the right ventricular apex. The MCV was identified with standard angiography techniques and a 4080 (Angeion Corp.) defibrillation electrode (1.6 mm x 65 mm) introduced into the vein. An active can was implanted in the left subpectoral region. The defibrillation thresholds (DFT) of the following defibrillation configurations were assessed using a modified four-reversal binary search: RV-->Can, RV + MCV-->Can and MCV-->Can. The DFT's for the three configurations were 15.5 +/- 2.8 J, 10.8 +/- 3.4 J and 13.7 +/- 2.4 J. Analysis of variance showed that the DFT with the RV + MCV combination was significantly less than the RV alone (p < 0.05)

CONCLUSIONS

Defibrillation is possible through the MCV and that incorporating an electrode in the MCV with RV-Can configuration can reduce the DFT by 30%.

A combined cytogenetic and molecular approach to diagnosis in a case of desmoplastic small round cell tumor with a complex translocation (11;22;21)

Desmoplastic small round cell tumor (DSRCT) has recently been described as a discrete tumor entity. It is distinguished from other small round cell tumors by its prominent desmoplastic quality, its preponderance in adolescent males, its almost exclusive intraabdominal location, a multi-immunophenotypic profile, and its aggressive nature. Diagnosis on histology alone is not always unequivocal. A recurrent t(11;22)(p13;q12) translocation has recently been described in this tumor, and a chimeric RNA fusion product formed from the WT1 and EWS genes is detectable by reverse transcriptase-polymerase chain reaction (RT-PCR). We describe the use of a multi-faceted approach using conventional G-banding, fluorescence in situ hybridization (FISH) and RT-PCR to assist the diagnosis of a case of DSRCT with a complex variant t(11;22;21)(p13;q12;q22.1) translocation and demonstrate the value of a combined approach to genetic investigation of solid tumors.

Preliminary single center clinical experience of the use of a new implantable cardioverter defibrillator

We report a single center's preliminary clinical experience of the Sentinel (Angeion, Minneapolis, MN) implantable cardioverter defibrillator (ICD), which employs novel technologies that offer the potential for significant reduction in ICD size. Thirty-three patients have received Sentinel ICDs with a mean follow-up of 450 (range 150-1023) days. Device shock therapy has been used to defibrillate/cardiovert 43 spontaneous episodes of malignant ventricular arrhythmia and 510 episodes of hemodynamically well tolerated ventricular arrhythmia have been pace-terminated (pace-termination failed in 6 episodes with subsequent delivery of appropriate shock therapy). There has been no arrhythmic death in this patient population. There have been 9 inappropriate shocks in 6 patients (in 2 patients for atrial fibrillation which had satisfied the algorithm detection criteria for high zone ventricular arrhythmia, in 3 for sinus tachycardia [rate greater than 180 beats per min] and in 1 due to device capacitor malfunction). Device replacement has been required for component malfunction in 3 patients. There have been no other major complications. Follow-up time to date is short and longterm device efficacy and performance remain unproven. However, our early clinical experience suggests that the innovations used to manufacture the Sentinel ICD have facilitated reduction in ICD size without compromising therapeutic efficacy.

Uroplakin gene expression by normal and neoplastic human urothelium

cDNA sequences for human uroplakins UPIa, UPIb, UPII, and UPIII were cloned and used to investigate uroplakin transcription by normal and neoplastic urothelial cells. Normal urothelium expressed mRNA for all four uroplakins, although UPIII could be detected only by ribonuclease protection assay. By in situ hybridization, UPIa and UPII were confined to superficial cells and UPIb was also expressed by intermediate cells. Cultured normal human urothelial cells showed a proliferative basal/intermediate cell phenotype and constitutive expression of UPIb only. Uroplakin expression by transitional cell carcinoma cell lines was related to their differentiated phenotype in vitro. RT4 cells expressed all uroplakins, VM-CUB-3 expressed three uroplakins, RT112 and HT1376 cells expressed only UPIb in high abundance, and COLO232, KK47, and EJ cells had no detectable expression. These results correlated with patterns of uroplakin expression in tumors. UPIa and UPII were detected superficially only in well differentiated transitional cell carcinoma papillae. UPIb was positive in seven of nine and overexpressed in five of nine noninvasive transitional cell carcinomas and was also present in four of eight invasive transitional cell carcinomas. Lymph node metastases retained the same pattern of UPIb expression as the primary tumor. Unlike the three differentiation-regulated uroplakins, UPIb may have an alternative role in urothelial cell/tissue processes.

Annual cycle in LH and testosterone release in response to GnRH challenge in male woodchucks (Marmota monax)

Testosterone and LH concentrations were determined in serum samples obtained before and 15 min after injections of GnRH (1 microgram kg-1) administered at 4-7 week intervals over 20 months to groups of male woodchucks (n = 6-7) born and maintained in Northern Hemisphere (boreal) versus Southern Hemisphere (austral) simulated natural photoperiods, beginning at 18-24 months of age. Nadir and peak unstimulated testosterone (0.1 +/- 0.01 and 7.0 +/- 0.1 ng ml-1, respectively) and LH (0.8 +/- 0.2 and 8.1 +/- 1.1 ng ml-1, respectively) concentrations did not differ in boreal versus austral males. In the five boreal and five austral males that were confirmed to be photoentrained, basal (pre-GnRH) concentrations of LH and testosterone were lowest in summer, increased simultaneously in late autumn or early winter, and declined in the spring. GnRH stimulated some LH release throughout the year except for a 1-4 month period in the summer. The initial annual increase in the LH response to GnRH occurred in early autumn, and in 17 of 20 cycles it occurred 1-2 months before the initial increase in basal LH was detected. In the three free-running males not entrained to the photoperiod, the endocrine patterns were similar but were advanced by several months. The results demonstrate that in woodchucks there is a late autumn increase in LH secretion associated with the onset of testicular recrudescence, and an early autumn increase in pituitary response to GnRH before a detectable increase in serum testosterone.

Assessing students' clinical performance

In this article the authors review the history of clinical assessment and describe the development and implementation of an evidence-based assessment strategy for clinical practice prepared for the Diploma in Nursing curriculum at Keele University.

Gauge Capability Analysis: classical versus ANOVA

In order to use Statistical Process Control (SPC) efficiently and effectively in today's modern industrial environment, it is essential to analyze and determine the extent of gauge variability. The variation that occurs on a control chart is essentially a combination of product and gauge variation. Studies of measurement or gauge variation are absolutely a waste of resources unless they can lead to a substantial reduction in process variability or to an improvement in process and product quality. The goal of gauge capability analysis is an understanding and quantification of the various sources of variability present in the measurement process. The purpose of this paper is to illustrate the fundamental difference between Classical Gauge Capability Analysis (CGCA) and the use of a more powerful approach based on the Analysis of Variance (ANOVA). The author recommends that the latter approach is more useful and powerful in the presence of an interaction between the parts and the operators involved in the measurement process. An example is illustrated in the paper to demonstrate the two approaches.

Pulmonary tuberculosis in Harare, Zimbabwe: analysis by spoligotyping

BACKGROUND

Over the last 10 years there has been a fourfold increase in cases of tuberculosis in Harare, Zimbabwe. The use of molecular epidemiology to understand tuberculosis transmission in this epidemic has been hampered by the availability of suitable culture facilities. A study was therefore undertaken to explore the potential of spoligotyping, a polymerase chain reaction based technique that does not require tuberculosis culture.

METHODS

Adults attending a chest clinic with clinical or radiological pulmonary tuberculosis and one smear positive sputum were enrolled over one month. Demographic, socioeconomic, and clinical data were gathered using a standardised questionnaire. Molecular fingerprinting of genomic DNA recovered from sputum was performed by spoligotyping.

RESULTS

Sixty one subjects (median age 28 years (range 18-73); 61% men) were recruited and 57 provided adequate sputum samples. Recent rural-urban migration or immigration was not common; 40% of subjects lived in crowded living conditions. DNA suitable for spoligotyping was recovered from 28 patients and 20 different genotypes of Mycobacterium tuberculosis were identified. Fifteen patients were infected with an M tuberculosis strain shared by one or more individuals. Patients infected with a shared spoligotype were not closely linked geographically within Harare, but were more likely to live in overcrowded conditions (69% versus 23%; odds ratio 6.85 (95% CI 1.2 to 47), p = 0.026). Analysis of the patients' original rural family homes revealed two geographically related spoligotype clusters.

CONCLUSIONS

Spoligotyping may yield valuable molecular typing information in populations where tuberculosis culture is not available. This novel technique requires further development and evaluation in larger epidemiological studies.

In vitro and in vivo antifungal activity of amphotericin B lipid complex: are phospholipases important?

Amphotericin B lipid complex for injection (ABLC) is a suspension of amphotericin B complexed with the lipids L-alpha-dimyristoylphosphatidylcholine (DMPC) and L-alpha-dimyristoylphosphatidylglycerol. ABLC is less toxic than amphotericin B deoxycholate (AmB-d), while it maintains the antifungal activity of AmB-d. Active amphotericin B can be released from ABLC by exogenously added (snake venom, bacteria, or Candida-derived) phospholipases or by phospholipases derived from activated mammalian vascular tissue (rat arteries). Such extracellular phospholipases are capable of hydrolyzing the major lipid in ABLC. Mutants of C. albicans that were resistant to ABLC but not AmB-d in vitro were deficient in extracellular phospholipase activity, as measured on egg yolk agar or as measured by their ability to hydrolyze DMPC in ABLC. ABLC was nevertheless effective in the treatment of experimental murine infections produced by these mutants. Isolates of Aspergillus species, apparently resistant to ABLC in vitro (but susceptible to AmB-d), were also susceptible to ABLC in vivo. We suggest that routine in vitro susceptibility tests with ABLC itself as the test material may not accurately predict the in vivo activity of ABLC and that the enhanced therapeutic index of ABLC relative to that of AmB-d in vivo may be due, in part, to the selective release of active amphotericin B from the complex at sites of fungal infection through the action of fungal or host cell-derived phospholipases.

Dietary peptides improve wound healing following surgery

To determine if peptide-based enteral diets improve wound healing when compared to amino acid-based diets, a prospective randomized study was conducted using 38 male Sprague-Dawley rats. Following placement of a standardized abdominal wound, 20 animals were randomized to an isonitrogenous peptide-based (PEP) versus amino acid-based diet (AA) for 10 d. In addition, 18 animals were randomized to an amino acid-based diet supplemented with the peptide carnosine (CARN) or its constituent amino acids (Control). Diets were administered through small bowel feeding tubes. Wound bursting pressure was significantly higher in the PEP animals compared to the AA animals (179+/-9 versus 138+/-12 mmHg; P=0.02). In addition, wound bursting pressure was significantly greater in the CARN animals compared to the Control animals (143+/-10 versus 116+/-8 mmHg; P=0.005). Peptide-based enteral diets improve wound healing when compared to nonpeptide generating amino acid-based diets. We also conclude that the dietary peptide carnosine represents a dietary peptide that improves wound healing when administered as part of a complete enteral formula. This effect on wound healing may be clinically relevant because carnosine is not found in most enteral formulas.

Intensive cardiovascular risk factor intervention in a rural practice: a glimmer of hope?

BACKGROUND

Large trials of primary care-based health promotion to modify coronary heart disease risks have shown only modest benefits. Could more intensive intervention, with doctors sharing with practice nurses in health promotion, produce better health outcomes in the context of the small family practice? How cost-effective might these interventions be?

AIM

To assess the cost-effectiveness of an intensive programme of coronary heart disease (CHD) risk factor modification in a rural general practice in which doctors had a major input.

METHOD

A longitudinal study of changes in risk factors in a group of adult patients identified as having one or more major CHD risk factor and monitored for one to seven years. Patients were recruited from and followed up in health promotion clinics, routine practice nurse appointments, or routine doctors' surgeries. All received the practice's routine interventions to modify risk, and changes in risk factors were recorded. Time spent by members of the primary health care team on CHD health promotion was recorded over a two-year period.

RESULTS

From a practice list of 2040, 760 patients with one or more CHD risk factors were identified and followed up over a mean of 3.61 years (range six months to seven years). Significant improvements in each of the risk factors occurred, except in body mass index (BMI). Mean Dundee risk scores fell from 7.4 to 5.7 (by 23.3%). The annual cost to the practice (including doctor/nurse/secretarial time plus sundry practice expenses and laboratory costs, but excluding drug costs) was 6000 pounds. Cost per coronary death prevented was calculated as approximately 10,000 pounds.

CONCLUSION

The results show an effect on risk factors broadly similar but slightly greater in magnitude than that achieved in the OXCHECK and British Family Heart Studies of nurse-delivered risk factor intervention in primary care. The results suggest that more intensive effort in lifestyle modification and health promotion, with more active involvement of doctors, could produce significant additional benefit. The cost-effectiveness of this approach compares favourably with many other accepted measures in coronary heart disease prevention.

Inv(10)(p11.2q21.2), a variant chromosome

We present 33 families in which a pericentric inversion of chromosome 10 is segregating. In addition, we summarise the data on 32 families in which an apparently identical inv(10) has been reported in the literature. Ascertainment was through prenatal diagnosis or with a normal phenotype in 21/33 families. In the other 12 families, probands were ascertained through a wide variety of referral reasons but in all but one case (a stillbirth), studies of the family showed that the reason for referral was unrelated to the chromosome abnormality. There has been, to our knowledge, no recorded instance of a recombinant chromosome 10 arising from this inversion and no excess of infertility or spontaneous abortion among carriers of either sex. We propose that inv(10)(p11.2q21.2) can be regarded as a variant analogous to the pericentric inversion of chromosome 2(p11q13). We conclude that prenatal chromosome analysis is not justified for inv(10) carriers. In addition, family investigation of carrier status is not warranted in view of the unnecessary concern this may cause parents and other family members.

Long-term entrainment of circannual reproductive and metabolic cycles by Northern and Southern Hemisphere photoperiods in woodchucks (Marmota monax)

Woodchucks were exposed to simulated Northern Hemisphere (boreal) or Southern Hemisphere (austral) natural photoperiods in groups of 17 males and 17-18 females at 20-23 degrees C for 69 mo and examined monthly. Photoentrainment of endogenous cycles was evaluated based on dates of peak body weight, peak testis volume, increased serum testosterone in males, and increased serum progesterone in females. Boreal photoperiods entrained and synchronized annual cycles in 15 of 17 males and in all 17 females; 2 males never entrained and free-ran at 9- to 11-mo intervals. Austral photoperiods phase-advanced cycles by approximately 6 mo after 2.5 yr in 34 of 35 animals. Four entrained males became refractory after 4 yr, free-running at 6- to 10-mo intervals. Photoentrained boreal animals became phase-advanced by 1 mo during the first 2 yr, and then had 12-mo cycles for 4 yr. In Year 5, on average, boreal cycles included initial testosterone elevations in mid-January (vs. mid-July in australs), parturition in early March (vs. early September in australs), and peak body weight in mid-July (vs. late January in australs). The results confirm that endogenous circannual cycles of woodchucks can be entrained and synchronized for 6 yr by daily changes in photoperiod similar to those of midnorthern latitudes, and can be re-entrained and phase-advanced 6 mo by photoperiods of midsouthern latitudes.

The host environment determines strain-specific differences in the timing of skeletal muscle regeneration: cross-transplantation studies between SJL/J and BALB/c mice

The difference in the timing of the regeneration process of skeletal muscle between SJL/J and BALB/c mice was investigated using grafts of whole skeletal muscle (both autografts and allografts). Histological, autoradiographic and immunohistochemical techniques were used in the investigation. Infiltration of leucocytes into autografts, numbers of desmin-positive myogenic cells and myotube formation were all more advanced in the SJL/J compared with BALB/c mice. Furthermore, autoradiographic evidence showed that myoblasts in the SJL/J autografts were synthesising DNA 12 h earlier than myoblasts in BALB/c autografts. In allografts, where SJL/J host mice received BALB/c grafts, and vice versa, leucocyte infiltration and myotube formation occurred earlier in the BALB/c muscles grafted into SJL/J hosts, than in the reverse situation with BALB/c hosts. The results show that, at least for whole muscle grafts, it is the host environment which determines the speed and outcome of the regenerative process.

Enhancement of the in vivo circulation lifetime of L-alpha-distearoylphosphatidylcholine liposomes: importance of liposomal aggregation versus complement opsonization

Incorporation of N-(omega-carboxy)acylamido-phosphatidylethanolamines (-PEs) into large unilamellar vesicles (LUVs) of L-alpha-distearoylphosphatidylcholine (DSPC) was found to dramatically increase the in vivo liposomal circulation lifetime in rats, reaching a maximal effect at 10 mol.% of the total phospholipid. Neither pure DSPC liposomes nor those with the longest circulating derivative, N-glutaryl-dipalmitoylphosphatidylethanolamine (-DPPE), were found to significantly bind complement from serum. Therefore, the relatively short circulation time of pure DSPC liposomes did not appear to be related to greater complement opsonization leading to uptake by the reticuloendothelial system. However, N-(omega-carboxy)acylamido-PEs were particularly efficient inhibitors of a limited aggregation detected for pure DSPC liposomes. The aggregation tendency of DSPC liposomes incorporating various structural analogs of N-glutaryl-DPPE correlated inversely with the circulation lifetimes. Therefore, it is concluded that such PE derivatives enhance the circulation time by preventing liposomal aggregation and avoiding a poorly understood mechanism of clearance that is dependent on size but is independent of complement opsonization. At high concentrations of N-glutaryl-DPPE (above 10 mol.%), the liposomes exhibited strong complement opsonization and were cleared from circulation rapidly, as were other highly negatively charged liposomes. These data demonstrate that both the lack of opsonization and the lack of a tendency to aggregate are required for long circulation. Liposomal disaggregation via N-(omega-carboxy)acylamido-PEs yields a new class of large unilamellar DSPC liposomes with circulation lifetimes that are comparable to those of sterically stabilized liposomes.