bluuebunny/crossref_metadata_2025 huggingface dataset:
Personal performance profiles: a useful adjunct to quality assurance in cervical cyt_logy
Authors: HOULISTON  , BOYD  , NICHOLAS  , SMITH
Published: March 2003

houliston d. c., boyd c. m., nicholas d. s. and smith j. a. (1998) Cyt_pathology,9, 162–170

Personal performance profiles: a useful adjunct to quality assurance in cervical cyt_logy

In our laboratory, which processes approximately 40 000 smears annually, the reporting patterns of each individual primary screener have been continuously monitored over a 6‐year period. The detection rates for minor abnormalities (borderline/mild dyskaryosis) and major abnormalities (moderate dyskaryosis and worse) are published quarterly in the laboratory. Individual continuous monitoring rapidly identifies screeners with low detection rates. It is a useful adjunct to existing methods of quality assurance; rescreening can be more appropriately directed to smears reported by screeners with low detection rates. It also identifies training needs and may be used to assess the value of update courses for each screener. It is a faster method of identifying poor performance than rapid review of all smears. The reporting rate of inadequate smears is also calculated and published on a quarterly basis. This promotes a degree of uniformity within the laboratory in the rate at which smears are reported as inadequate, and also reduces the inadequate rate.
Quality procedures in non‐gynaecological cytology laboratories in England and Wales
Authors: Egan M. , Gray J.
Published: March 2003

Quality procedures in non‐gynaecological cytology laboratories in England and Wales

All non‐gynaecological cytology laboratories in England and Wales (n = 212) were surveyed by telephone. The aim was to investigate what concepts of quality applied in this context and to establish what tools and techniques of quality improvement were used. The overall response was 146 (69%). The respondents mainly comprised NHS Trusts and University Departments. The study showed that there was a diverse approach to quality. All types of quality assurance and customer focus procedure questioned were undertaken but to a varied extent; three laboratories (2%) used a complete range and three (2%) used no procedure at all. Accreditation was associated with staffing adequacy and use of surveys, but not quality assurance (QA) or user focus. Laboratories with a high priority for quality performed more QA and reported a higher staffing adequacy. Critical incident analysis was dependent on workload. Computerization did not affect quality procedures and involvement in the Breast Screening Programme did not result in different quality measures. The time since last update was independent of all factors and external quality assurance (EQA) was not widely available. The study suggested that an integrated approach to quality had not been adopted in English and Welsh cytology laboratories and that there may be a need for a more strategic approach with greater availability of EQA, guidelines on quality tools, closer linkage of accreditation and quality procedures and the production of minimum and ideal standards. The ideal standard could be the complete range of procedures, and the minimum standard could comprise those processes in most frequent use, i.e. critical incident analysis, correlation methods, action on information, analysis of what is done with diagnostic information, a complaints procedure and customer surveys.
Prospective study of PAPNET: review of 25656 Pap smears negative on manual screening and rapid rescreening
Authors: Halford J. A. , Wright R. G. , Ditchmen E. J.
Published: March 2003

Prospective study of PAPNET: review of 25 656 Pap smears negative on manual screening and rapid rescreening

In this prospective study, 27014 Pap smears were selected for PAPNET review on the request of the referring practitioner or patient. Smears that were negative on routine manual screening were submitted for rapid rescreening. Smears considered normal after these two manual screens (n = 25656) were reviewed using the PAPNET testing system. Routine manual screening identified 1340 (4.96%) of the smears as abnormal, and a further 18 (0.07%) abnormalities were detected by rapid rescreening. PAPNET review identified an additional 102 (0.4%) abnormal smears, including 10 histologically confirmed high grade lesions. The use of PAPNET testing following routine manual screening and rapid rescreening in tandem, enables cytologists to detect additional diagnostically significant abnormalities and reduce the rate of false‐negative smears.
A survey of biomedical scientists and consultant pathologists involved in the cervical screening programme
Authors: Brown D. C. , Griffiths D.
Published: March 2003

A survey of biomedical scientists and consultant pathologists involved in the cervical screening programme

The past decade has seen a transformation in the National Health Service Cervical Screening Programme (NHSCSP) largely driven by responses to various screening scandals. Independent inquiries into these laboratory failures have identified a number of contributing factors. The aim of this postal survey was to determine how widespread these factors are throughout screening laboratories in England. The results indicate that issues around recruitment and retention of staff, the training of pathologists and low morale appear to be widespread. However, the results do not indicate a widespread breakdown in working relationships between consultants and biomedical scientists, although there is room for improvement in their relationships with hospital management. Finally, there seem to be mixed messages about the commitment of consultants to the screening programme.
Cytological diagnosis of bronchopneumonia at post mortem
Authors: Beer T. W. , Maidment G. , Mikel J. J. , van Wyk Q. , Pullinger N. C.
Published: March 2003

Cytological diagnosis of bronchopneumonia at post mortem

We assessed the value of cytology in the rapid diagnosis of bronchopneumonia at post mortem. Cytology scrapes were taken from 249 lung lobes during 50 autopsies. Slides were stained with a modified Giemsa technique and a neutrophil polymorph score recorded on a scale of 0–3. Histology blocks from the same area were then scored for the degree of bronchopneumonia present. Bronchopneumonia was found histologically in 22 patients, but macroscopic examination had identified only eight of these. A cytological neutrophil polymorph score of 2 or more to indicate bronchopneumonia yielded a sensitivity of 52% and a specificity of 98% in terms of lobes. This gave a positive predictive value of 92% and a negative predictive value of 86% for the presence of bronchopneumonia. All eight patients with a cytology score of 3 had histological evidence of bronchopneumonia. Conversely, all patients with a definitive diagnosis of bronchopneumonia exhibited cytology scores of at least 1. Post mortem cytology scrapes reliably predict bronchopneumonia and are superior to gross examination. This is a rapid, reliable and cheap method that can be readily performed in all necropsy practices.
Personal commentaryWho should be reporting gynaecological cytopathology?
Authors: Anthony P. P.
Published: March 2003

If I were Rip van Winkle and woke up after a 30‐year‐long slumber, I could find much that is new in cervical cancer screening except for one thing. Medically qualified consultant histo/cytopathologists are still expected to look at, and report on, all abnormal smears and biomedical scientists/medical laboratory scientific officers can only play an intermediate role between screeners and consultants. This practice has been cast in stone by expert committees of both the British Society for Clinical Cytology (BSCC)1,2 and the Royal College of Pathologists (RCPath)3 in the following terms: ‘All abnormal smears, including those with borderline nuclear changes, should be reported by a cytopathologist …’1 and ‘The laboratory should be supervised by a consultant cytopathologist and he/she, or deputy, should be in attendance at the laboratory every working day … The cytopathologist should see all abnormal material and a proportion of the negative material …’2 and ‘Cervical screening specimens in which abnormal or equivocal cells are present must … be examined by a pathologist …’3> (wording unchanged in two subsequent editions).
The effect of nonscreening smears on screening smear results: a statistical analysis with its implications for the NHS cervical screening programme
Authors: Rice S. , Slater D. N. , Hewer E. M.
Published: March 2003

The effect of nonscreening smears on screening smear results: a statistical analysis with its implications for the NHS cervical screening programme

This is a statistical analysis of individual NHS Cervical Screening Programme laboratories screening smear ‘pick‐up’ rates (defined here as percentage low grade and percentage high grade of total adequate smears for ages 20–64 years derived from general practitioners and community clinics) in relation to their nonscreening smear workload proportion (here defined as percentage nonscreening smears of total laboratory workload from all sources for all ages). This was achieved by the use of three one way anova models in order to receive a complete overview of the results. The models were applied to the following: (1) Laboratories with a total workload of less than 15 000 general practitioner (GP) and community clinic smears; (2) laboratories with a total workload of greater than 15000 GP and community smears and; (3) all laboratories (i.e. a combination of 1 and 2). The ‘test’ groups within each of these models comprised three subgroups based on the percentage of laboratory workload that consisted of smears from a nonscreening source. This figure ranged from 2.8% to 82.6%. The subgroups were divided so as to contain approximately the same number of laboratories in each one (172 laboratories in total, 42 with workload < 15000 and 130 with > 15000). The results show that laboratories high and low grade pick‐up rates have a positively correlated but variable relationship with the proportion of their workload that consists of nonscreening smears. The results show significance overall at the 5% level for high grade and the 10% level for low grade (high grade at P= 0.045 and low grade at P= 0.071). Significance for laboratories viewing less than 15000 screening smears at the 1% level (high grade P= 0.006 and low grade P= 0.005). They show no significance, however, for laboratories viewing more than 15000 screening smears (high grade P= 0.457 and low grade P= 0.622). There is an intriguing possibility that a greater exposure to abnormal smears results in a greater tendency to detect them. The current data provides no evidence to support the NHS Executive's use of 15000 as a designated figure when quality monitoring and service provision becomes a specific issue. The closure or amalgamation of laboratories with workloads less than this would appear to have no scientific evidence base.
Heterogeneous selective pressures on egg‐hatching time and the maintenance of its genetic variance in a Tetraneura gall‐forming aphid
Authors: AKIMOTO SHIN‐ICHI
Published: March 2003

1. The performance of gall‐forming aphids is largely dependent on the timing of egg hatch relative to host budburst. This study examined the mode of natural selection acting on egg‐hatching time and the extent of its genetic variance in a Tetraneura aphid.

2. The budburst time of the primary host of the aphid varied greatly among individual trees. Egg hatch on a host tree was often asynchronous with host budburst.

3. Transplant experiments indicated that egg‐hatching time was subject to heterogeneous selective pressures in heterogeneous host environments.

4. Hatching time was compared between half‐sib families. Small nymphs in a half‐sib family tended to hatch later, and this resulted in large within‐family variance in hatching time.

5. Small nymphs that hatched late were likely to be selected out during the galling process. Thus, these nymphs may be produced not as bet‐hedging but due to maternal effects. When such maladapted nymphs were not included in analysis, a significant amount of additive genetic variance was detected in hatching time.

6. Heterogeneous selection, coupled with density‐dependent regulation of population on respective host trees, probably maintains additive genetic variance in this trait.
Escaping an ecological dead‐end: asexual overwintering and morph determination in the lettuce root aphid Pemphigus bursarius L.
Authors: Phillips S. W. , Bale J. S. , Tatchell G. M.
Published: March 2003

1. Pemphigus bursarius exhibits a host‐alternating life‐cycle, overwintering as eggs on the primary host plant (poplar) before migrating in summer to the secondary host plant (mainly annual Compositae). A proportion of the population does not produce return migrants (sexuparae) in the autumn but remains in the soil and overwinters as asexual apterae, even after the annual plants have died in early winter. Laboratory and field experiments investigated the biology and overwintering success of these asexual apterae.

2. Both temperature and photoperiod are important in morph determination. The highest number of apterae (approximately 50% of progeny) was produced in a 20 °C, LD 18 : 6 h regime. Very few apterae were produced in an alatae‐inducing environment (15 °C, LD 12 : 12 h), but the proportion increased over successive generations.

3. Apterae remaining in the soil in the autumn overwintered successfully in large numbers and were able to reinfest directly the root systems of newly planted lettuce grown in the same field in the following growing season.

4. Overwintered asexual populations also produced alates in July, which were able to colonise other lettuce plants, indicating that they were not sexuparae. Hence, P. bursarius can avoid the ecological dead‐end that would occur through local patch extinction. Clones can therefore persist indefinitely as both asexual apterae and alatae without the need to return to poplar and undergo the sexual phase of the life‐cycle.
Host‐mediated effects of feeding by winter moth on the survival of Euceraphis betulae
Authors: Staley J. T. , Hartley S. E.
Published: March 2003

Abstract 1. A potential host‐mediated interaction between the birch‐feeding aphid Euceraphis betulae Koch (Homoptera: Aphididae) and Operophtera brumata L. (Geometridae: Lepidoptera) was investigated, by measuring survival and feeding preference responses of E. betulae to leaves damaged recently by O. brumata larvae.

2. Euceraphis betulae survival was considerably lower on damaged foliage than on undamaged foliage, both in field experiments using cages and on potted saplings in laboratory tests.

3. Euceraphis betulae did not avoid damaged foliage in field experiments although they did avoid damaged foliage in laboratory preference tests using individual leaves. A link between aphid preference and performance on damaged foliage could therefore be demonstrated in the greenhouse/laboratory but not in the field. Multiple factors may influence feeding preference in the more complex field environment.

4. These results suggest that host‐mediated competition may occur between O. brumata and E. betulae, especially in outbreak years when winter moth populations are very high.
Co‐evolution between ectoparasites and their insect hosts: a simulation study of a damselfly–water mite interaction
Authors: Rolff Jens , Vogel Christine , Poethke Hans‐Joachim
Published: March 2003

1. A simulation model investigating the co‐evolution of water mites infesting their aquatic insect hosts during emergence is presented. The model is based on field and experimental studies of the ectoparasitic water mite Arrenurus cuspidator and the damselfly Coenagrion puella.

2. Three scenarios were studied: (1) Only the host was allowed to evolve timing of emergence, while the timing of the parasites' infestation opportunity was held constant. (2) Both host and parasite were allowed to evolve. (3) Only the parasite's timing was allowed to evolve, while the host was constrained completely.

3. In the first two scenarios, parasite abundances decreased in the course of evolution and reached values well below those found in the field, whereas in the third scenario, parasite abundances were maintained at a level close to that found in the field. In the second scenario (co‐evolution), the host seemed to be the leader in the evolutionary race.

4. It is concluded that water mite parasitism is capable of shaping emergence patterns in aquatic insects and, despite the same life‐cycle length for host and parasite, the parasite evolves fast enough to shape its hatching pattern to match the emergence pattern of its host.
The effect of past and current hosts on reproductive investment by the adult cowpea aphid Aphis craccivora
Authors: Traicevski Violeta , Ward Seamus A.
Published: March 2003

Abstract 1. A general index of accumulated investment that alate aphids make into reproduction with respect to environmental changes (specifically changes in host at adult moult) was investigated to determine whether and how reproduction in Aphis craccivora Koch changes once aphids migrate to a different host from the one on which they were born and reared. The aphids were monitored for 4 days to determine the immediate effects of a change in host.

2. A general index of accumulated investment defined as reproductive index was used; reproductive index is equal to the reproductive output (weight of nymphs born; actual fecundity) plus potential reproduction (weight of embryos within the ovarioles with red eye spots; future fecundity).

3. The results revealed that reproductive index is affected by adult weight. The host on which the aphids have been born and reared (source host) has no effect on reproduction other than its influence on adult weight.
Relationships between oviposition date, hatch date, and offspring size in the grasshopper Chorthippus brunneus
Authors: Cherrill Andrew
Published: March 2003

Abstract 1. The grasshopper Chorthippus brunneus has been shown to increase egg size with maternal age under constant laboratory conditions, such that late‐laid eggs are larger than early laid eggs. In this study, an increase in the size of eggs (and hatchlings from those eggs) was recorded with date of oviposition in a field cage population. This suggests that the relationship between maternal age and egg size, observed previously in the laboratory, also occurs in the field. There was, however, some evidence that the behaviour of the maternal females in field cages was modified by the onset of autumnal weather at the end of the breeding season. Only a small number of eggs was laid in the last 3 weeks of the summer but these yielded relatively small hatchlings.

2. The date on which eggs were laid was correlated positively with their date of hatch in the following year. A consequence of this relationship, and that between oviposition date and egg size, was that size at hatch increased with date of hatch through most of the spring but then declined as the last few eggs hatched. Temporal variation in size at hatch parallelled temporal variation in the maternal females' investment in egg size in the previous year.

3. An undisturbed field population was monitored to assess whether the temporal variation in size at hatch resulted in size variation at eclosion in subsequent developmental stages. There were negative correlations between size at eclosion and date of eclosion at the third and fourth instars, suggesting that despite their smaller size at hatch, early hatchers experienced more favourable conditions for juvenile growth than late hatchers. The larger size at hatch of late hatchers may enhance their survival and compensate (albeit incompletely) for their reduced opportunity for growth. Female reproductive behaviour may represent an adaptive response to a predictable seasonal decline in offspring fitness at hatch.
Spatial and temporal variation in the parasitoid assemblage of an exophytic polyphagous caterpillar
Authors: Stireman John O. , Singer Michael S.
Published: March 2003

Abstract1. Over 3400 larvae of the polyphagous ground dwelling arctiidGrammia geneurawere sampled and reared over seven generations in order to characterise its parasitoid assemblage and examine how and why this assemblage varies over time and space at a variety of scales.

2. The total parasitoid assemblage of 14 species was dominated both in diversity and frequency by relatively polyphagous tachinid flies.

3. Both the composition of the parasitoid assemblage and frequency of parasitism varied strikingly among and within sampling sites, seasons, and years.

4. Overall rates of parasitism increased consistently over the duration of caterpillar development.

5. Within sampling sites, parasitism rates were non‐random with respect to habitat structure and caterpillar behaviour for the most abundant parasitoid species.

6. The large variability in parasitoid assemblage structure over space and time in this system may be a function of local host population abundance, habitat‐specific parasitism, and indirect interactions betweenG. geneuraand other Macrolepidoptera through shared oligophagous and polyphagous parasitoids.
Measuring the sperm competition successes of field males of the yellow dung fly
Authors: Ward Paul I. , Wedell Nina , Hosken David J. , Tregenza Tom
Published: March 2003

Abstract 1. Sperm competition is extremely common in many species but conclusions about the relative successes of males, measured as the proportion of a female's offspring fertilised by the second male to mate with it, are based largely on laboratory studies using two laboratory‐bred males or on interrupted last copulations.

2. A study was conducted in which virgin female yellow dung flies Scathophaga stercoraria mated uninterrupted with two field‐captured males.

3. The results confirmed two previous conclusions: the proportion of a female's offspring fertilised by the second male was related strongly to the copula duration of the second male, and the proportion of a female's offspring fertilised by the second male was lower in larger females, though this effect was weak.

4. The results indicate that previous experiments on laboratory populations of this species are likely to be relevant to wild situations, but researchers are urged to conduct studies that will improve the confidence with which laboratory measures of the proportion of a female's offspring fertilised by the second male can be assumed to reflect the sperm precedence of the last male to mate in natural situations.
Life history of Kladothrips ellobus and Oncothrips rodwayi: insight into the origin and loss of soldiers in gall‐inducing thrips
Authors: Kranz Brenda D. , Schwarz Michael P. , Morris David C. , Crespi Bernard J.
Published: March 2003

1. The evolution of eusociality in Australian gall‐inducing thrips cannot be understood without comparisons among closely related solitary species. The life history of two solitary, gall‐inducing thrips, Kladothrips ellobus and Oncothrips rodwayi, was investigated, and data for solitary and eusocial species from previous studies were re‐analysed. Kladothrips ellobus is in a clade that is closely related to the eusocial species. Oncothrips rodwayi is in the same clade as the eusocial species and appears to have undergone an evolutionary loss of eusociality. It is the only galling thrips on Acacia in temperate environments.

2. The brood size of K. ellobus is eight to 23 times larger than broods of foundresses in eusocial species whereas the brood size of O. rodwayi is not significantly different from those of foundresses in eusocial species.

3. In K. ellobus, the mean sex ratio was not significantly different from parity but in O. rodwayi the mean sex ratio was 0.13 male. In O. rodwayi, 77% of females were inseminated by their brothers before dispersal, which is consistent with high levels of inbreeding in eusocial species of the same clade. Sex ratios suggest random mating in K. ellobus whereas female‐biased sex ratios in O. rodwayi are consistent with inbreeding and local mate competition.

4. Comparisons among solitary and eusocial species suggest that large brood size is an ancestral trait for eusociality in thrips, and this trait persists in solitary species as an r‐selection strategy. Soldiers may have evolved in arid environments to minimise the risks of dispersal and the costs of latency to reproduction, and to maximise gall defence.

5. Temperate conditions could have facilitated the evolutionary loss of soldiers in O. rodwayi, as there should be a shorter, safer, more predictable window period between dispersal and gall induction, reducing the period of latency to reproduction following dispersal and lowering risks of dispersal.

6. The loss of soldiers in O. rodwayi is not associated with a reversion to the large brood sizes of solitary species in ancestral lineages.
Construction of a cDNA library of Bemisia tabaci for use in the ‘yeast two‐hybrid screen’ method
Authors: Ohnesorge S. , Bejarano E. R.
Published: March 2003

The molecular mechanisms involved in the circulative, non‐propagative transmission pathway of TYLCV through its vector the whitefly Bemisia tabaci have hardly been studied. Points requiring investigation include the specific adhesion of virus coat protein to insect structures, the proteins involved in membrane passage in the insect and the possibility of replication of the virus in the vector. To isolate the insect proteins which are involved in transmission by interaction with viral proteins, we propose to use the ‘yeast two‐hybrid screen’ genetic method. For this method, it is indispensable to have a ‘cDNA library’ of the organism concerned, cloned in plasmids, and our first step has been to develop this. A new method was developed for isolating whitefly mRNA. From this mRNA, cDNA was synthesized, ligated in the plasmid pGADT7 (Clontech) and transformed in bacteria to amplify the plasmid DNA. The number of independent clones and average insert size of the plasmids were determined.
Improved identification of Pseudomonas savastanoi pv. phaseolicola at the molecular level
Authors: Borowicz B. P. , Maćkowiak A. , Pospieszny H.
Published: March 2003

Polymerase chain reaction (PCR) technology was used to identify Pseudomonas savastanoi pv. phaseolicola at the DNA level. Oligonucleotide primers were designed on the basis of the DNA sequence of the phaseolotoxin gene cluster of P. s. phaseolicola. Identification of the pathogen was significantly improved and appearance of unspecific bands was greatly diminished by experimentally selecting the most suitable annealing temperature (Tm) value. We obtained a single, strong DNA band of 1.4 kb length, specific for the identification of P. s. phaseolicola, using a PCR programme based on a Tm value of 80 °C.
Augmentation of the number of nucleolar organizer regions in human megakaryocyte cell lines after induction of polyploidization by a microtubule inhibitor
Authors: Baatout  , Chatelain  , Staquet  , Symann  , Chatelain
Published: March 2003

Background

Megakaryocyte polyploidization is an advantageous and regulated mechanism that leads to an increase in platelet production. In megakaryocytic cell lines, polyploidization can be obtained by using colchicine, an inhibitor of the tubulin spindle. The nucleolar organizer regions (AgNORs) are parts of nucleolar DNA transcribed into ribosomal RNA and are detected by the silver‐staining technique. Their number is proportional to protein synthesis.

Results

To estimate protein synthesis in polyploid megakaryocytes, AgNORs are measured in three cell lines with megakaryocyte properties (DAMI, HEL and K562) after a 4‐day culture in the presence or absence of colchicine. The mean number of AgNORs per cell was 16 ± 4 (mean ± SEM), 24 ± 3 and 14 ± 3 for DAMI, HEL and K‐562 cell lines respectively. The addition of colchicine (10 ng mL−1) significantly increased the number of AgNORs per cell (DAMI 556%, HEL 338% and K‐562 300% of controls, P < 0.05 using the t‐test). Moreover, the number of nucleoles per cell after the addition of colchicine was augmented significantly (DAMI 246%; HEL 237% and K‐562 148% of controls, P < 0.05 using the t‐test). The total protein content estimated by Bradford's method increased significantly to 226%, 215% and 304% of controls in DAMI, HEL and K562 respectively (P < 0.05 using the t‐test). After treatment with colchicine, the endomitotic index (EI) [mean of (log2 DNA content expressed in N) — 1] measured by flow cytometry (and reflecting ploidy) increased to 234%, 255% and 301%, respectively, in DAMI, HEL and K‐562 cell lines (P < 0.05 using the t‐test). Concomitantly, the number of AgNORs per unit of DNA increased in the DAMI and HEL cell lines (P < 0.05 using the t‐test) from 48 ± 8 and 39 ± 5, respectively, to 79 ± 11 and 61 ± 10. In contrast, the number of nucleoles and the total protein content per endomitotic index were not affected by colchicine (P  > 0.05 using the t‐test), but the number of nucleoles per endomitotic index of DAMI cells was affected.

Conclusion

The increase in the number of the NORs induced by an agent known to stimulate polyploidization of megakaryocytic cell lines suggests that polyploidization occurs by a proportional increase in protein synthesis per DNA unit.
Glutathione and HIV infection: reduced reduced, or increased oxidized?
Authors: Staal
Published: March 2003

Glutathione is the main intracellular defence against oxidative stress and regulates the cellular redox potential. HIV infection is accompanied by severe metabolic and immune dysfunctions. Several laboratories have demonstrated that the intracellular redox balance is disturbed in CD4+ T cells from HIV‐seropositive subjects, which may potentiate HIV replication and partly explain the immunological abnormalities associated with HIV disease. The importance of glutathione for immune function, regulation of gene expression, as well as therapeutic interventions with redox‐active drugs are discussed in this commentary.
Forearm composition contributes to differences in reactive hyperaemia between healthy men and women
Authors: Wascher  , Bammer  , Stollberger  , Bahadori  , Wallner  , Toplak
Published: March 2003

Background

Post‐ischaemic reactive hyperaemia in the forearm has been suggested as a marker of resistance vessel function. The contribution of forearm composition to the kinetics of reactive hyperaemia is largely unknown. The body composition of men and women differs in that women have a higher body fat content and less lean body mass.

Methods

In the present study, we investigated whether the kinetics of reactive hyperaemia in the forearm in 14 healthy subjects (seven men and seven women) show gender‐specific differences and whether forearm composition contributes to such differences.

Results

Peak reactive hyperaemic flow as well as 1‐min‐flow debt repayment (measured by venous occlusion plethysmography) were significantly higher in male than in female study participants. This difference was explained to > 60% by gender‐specific differences in forearm relative muscle mass (as determined by magnetic resonance imaging). The half‐life of the reactive hyperaemic response, on the other hand, was not different between men and women and did not show an association with forearm muscle.

Conclusion

Our results demonstrate that forearm composition must be considered if peak reactive hyperaemia or flow debt repayment is used as a target, and that dynamic measurements of the reactive hyperaemic process are more suitable to describe the function of resistance arteries than single‐point observations.
Gastric emptying of the liquid, solid and oil phase of a meal in normal volunteers and patients with Billroth II gastrojejunostomy
Authors: Maes  , Hiele  , Geypens  , Ghoos  , Rutgeerts
Published: March 2003

Background

The relationship between gastric emptying of different phases of a meal in humans has only been partly studied in normal subjects and in patients with previous gastric surgery.

Methods

In the present study, gastric emptying of the liquid, solid and oil phase and the relationship between the phases was evaluated in 10 normal control subjects and in seven patients with Billroth II gastrojejunostomy using breath test technology.

Results

Gastric emptying in normal subjects showed a clear separation between the emptying of the liquid, solid and oil phase. In healthy volunteers, the liquid phase emptied in the same manner in the presence of a solid phase as in the presence of an oil phase. In contrast, the oil phase emptied more slowly with liquids than with solids. The emptying rate of the oil phase was not only inversely related to the amount administered but was also dependent on its chemical composition. Gastric emptying in patients with Billroth II gastroenterostomy was characterized by a complete loss of discrimination between the different phases of the meal, with an extremely fast emptying of the oil phase compared with normal control subjects.

Conclusion

In normal subjects, the liquid, solid and oil phase of a meal are emptied differently. In patients with Billroth II gastrojejunostomy, dumping of the oil phase is the most pronounced difference from the normal physiology of gastric emptying. This could be one of the reasons why Billroth II gastrectomy may be associated with fat malabsorption.
Relationship between insulin's haemodynamic effects and insulin‐mediated glucose uptake
Authors: Ter Maaten  , Voorburg  , De Vries  , Ter Wee  , Donker  , Gans
Published: March 2003

Background

Insulin resistance and hyperinsulinaemia are associated with hypertension. The relationship between insulin's metabolic and haemodynamic actions has not been fully elucidated however.

Methods

We investigated, using the euglycaemic clamp technique, the relationship between insulin‐mediated glucose uptake and insulin‐induced changes in leg blood flow and cardiac index in 13 healthy subjects. As insulin's effects on blood flow are time dependent, studies were performed during a 4‐h insulin (50 mU kg−1 h−1) infusion period.

Results

Mean arterial pressure during insulin infusion increased (82.9 ± 6.7 to 89.8 ± 7.7 mmHg; P < 0.001), whereas heart rate was unaltered. Leg blood flow gradually increased from 1.09 ± 0.57 to 1.47 ± 0.67 mL min−1 dL−1 during the second hour, and to 1.65 ± 0.68 mL min−1 dL−1 during the fourth hour of the clamp (P = 0.01). Stroke volume index increased from 56.5 ± 13.3 to 63.7 ± 16.3 mL m−2 (P = 0.004) and cardiac index from 3.42 ± 1.02 to 3.73 ± 1.05 L min−1 m−2 (P = 0.04). The insulin‐mediated glucose disposal and the increases in leg blood flow were not correlated during the second hour (r = 0.21, P = 0.51) but showed a strong correlation during the fourth hour of the clamp (r = 0.88, P < 0.001). Insulin‐mediated glucose disposal was not correlated with the increases in cardiac index.

Conclusion

Thus, insulin‐mediated muscle blood flow may be an important contributor to glucose uptake during sustained exogenous hyperinsulinaemia aiming at physiological insulin levels.
Effects of endotracheal intubation on airway neuropeptide content, arterial oxygenation and lung volumes in anaesthetized rats
Authors: Högman  , Reber  , Hua  , Dueck  , Yaksh
Published: March 2003

Background

General anaesthesia affects lung volume and pulmonary gas exchange. What role is played by mechanical stimulation by the endotracheal tube?

Methods

We investigated the effects of intubation on arterial oxygenation and lung volume in rats.

Results

Endotracheal intubation caused an increase in PA–a
O2 and volume of trapped gas in the lung. This was accompanied by a reduction in neuropeptides and calcitonin gene‐related peptide (CGRP) in trachea, bronchi and lung, and in vasoactive intestinal peptide (VIP) in the trachea. The increase in PA–a
O2 and volume of trapped gas due to intubation was not altered in the animals given capsaicin, in which neuropeptide levels were reduced.

Conclusions

These data suggest that the decrease in CGRP and VIP content in the airway tissues may be one of the consequences, but not the cause, of impaired gas exchange by endotracheal intubation. The increase in volume of trapped gas in the lung is apparently not mediated by activation of capsaicin‐sensitive sensory nerves.
Influence of plasma phytanic acid levels in Refsum's disease on the behaviour of the erythrocyte membrane sodium–lithium countertransporter
Authors: Wierzbicki  , Hardman  , Lumb  , Sankaralingam  , Morrish  , Patel  , Sidey  , Gibberd
Published: March 2003

Background

Abnormal behaviour of the erythrocyte membrane sodium–lithium countertransporter (SLC) is associated with plasma triglyceride concentrations. Refsum's disease is characterized by progressive neurological dysfunction and accumulation of phytanic acid, an isoprenoid fatty acid, in fat‐containing tissues.

Methods

This study explored the effects of plasma phytanic acid on SLC kinetics in nine Caucasian patients with Refsum's disease and in age‐ and sex‐matched Caucasian control subjects.

Results

A dose‐dependent association was seen between countertransporter maximal velocity and phytanic acid content of low‐density lipoprotein (LDL)‐cholesterol (r = −0.61, r = −0.65 respectively; P = 0.05, P = 0.04) and high‐density lipoprotein (HDL)‐cholesterol (r = − 0.81, − 0.82 respectively; P = 0.005, P = 0.003). No significant association was seen with the sodium affinity of the transporter (r = − 0.44, P = 0.20, for LDL; and − 0.43, P = 0.21, for high‐density lipoprotein).

Conclusion

These findings suggest that phytanic acid may alter the behaviour of the sodium–lithium countertransporter.
Expression of tenascin is related to angiogenesis in pre‐eclampsia
Authors: Ribatti  , Loverro  , Vacca  , Greco  , Roncali  , Selvaggi
Published: March 2003

Methods

Ten samples of decidua basalis from pre‐eclamptic women and 10 from healthy primigravid women subjected to caesarean section (control tissues) were investigated immunohistochemically for changes in angiogenesis and expression of tenascin, an extracellular matrix protein thought to modulate angiogenesis. In addition, pre‐eclamptic and control samples were grafted onto the chick embryo chorioallantoic membrane (CAM) to study their possible angiogenic activity in vivo.

Results

Although the microvessel area was low in control samples, it increased significantly in the pre‐eclamptic decidua. In parallel, the area covered by tenascin staining underwent a significant expansion that was highly correlated with the microvessel area. Angiogenic activity was assessed both macroscopically and microscopically on histological sections 4 days after grafting. In contrast to control samples, pre‐eclamptic decidua induced an intense capillary growth, and numerous capillaries converging towards the implant and forming a spoke‐wheel pattern were evident. Histological examination using a planimetric point‐count method showed that microvessel counts in the CAM area under and around the pre‐eclamptic implants were significantly higher than those of control samples. Again, the extracellular matrix of nearby microvessels was strongly immunoreactive with tenascin.

Conclusion

It is suggested that, unlike normal decidua, pre‐eclamptic decidua displays an intense, autonomous angiogenic activity, probably mediated by tenascin in addition to its own angiogenic factors.
Sodium selenite and N‐acetylcysteine in antiretroviral‐naive HIV‐1‐infected patients: a randomized, controlled pilot study
Authors: Look  , Rockstroh  , Rao  , Barton  , Lemoch  , Kaiser  , Kupfer  , Sudhop  , Spengler  , Sauerbruch
Published: March 2003

Background

The aim of this work was to study the effects of combined oral administration of N‐acetylcysteine (NAC) and sodium selenite (Se) on plasma glutathione (GSH), lymphocyte subpopulations and viral load in asymptomatic human immunodeficiency virus (HIV)‐infected patients.

Methods

We used a prospective, randomized and controlled therapy trial with partial cross‐over. Twenty‐four antiretroviral‐naive HIV‐infected outpatients at Centers for Disease Control (CDC) '93 stages I and II were randomized to receive the antioxidant combination NAC 600 mg t.i.d. and Se 500 μg per day for either 24 weeks (group A, n = 13) or from the end of week 12 (group B, n = 11) until the end of week 24. Thus, group B served as untreated control during the first 12 weeks.

Results

There was (a) a trend towards an increase in the percentage of CD4+ lymphocytes after 6 weeks (P = 0.08); (b) an increase in the CD4/CD8 ratio after 6 and 12 weeks (P = 0.02 and P = 0.04 respectively); and (c) a decrease in the absolute CD8/CD38 count and percentage of lymphocytes after 6 weeks (P = 0.002 and P = 0.033 respectively) and 12 weeks (P = 0.033, P = 0.1 respectively) in group A compared with the control period of group B. The effects observed in group A were, however, not paralleled to the same extent by group B after crossing‐over to treatment after 12 weeks. In addition, erythrocyte glutathione peroxidase (GSH‐Px) activity and GSH, glutathionedisulphide (GSSG) concentrations and the reduced/total GSH ratio were not affected by the treatment. Serum selenium levels increased significantly (P < 0.001) upon treatment. Viral load was not altered.

Conclusions

The changes in lymphocyte subsets after NAC/Se treatment were not comparable to those after standard antiretroviral drug therapy. This, however, does not preclude per se possible benefits of antioxidant supplementation in HIV disease.
Hepatocellular defence against acidosis is preserved after cold storage
Authors: Helbling  , Renner
Published: March 2003

Background

Primary non‐function of liver allografts is related to preservation time, during which hypoxia leads to intracellular accumulation of acid. Preservation‐induced failure of hepatocellular pH regulation may play a role in the pathogenesis of primary graft non‐function.

Methods

Using cultured/suspended rat hepatocytes and fluorimetric determination of intracellular pH, we determined whether preservation in University of Wisconsin solution (4°C) impairs hepatocellular defence mechanisms against acidosis.

Results

In non‐preserved, 24‐h‐preserved and 48‐h‐preserved hepatocytes acidified to pH 6.7–6.8, initial Na+/H+ antiport‐mediated H+ fluxes averaged 12 ± 5, 9 ± 5 and 12 ± 5 nmol μL−1 min−1 and initial Na+/HCO3− symport‐mediated HCO3− fluxes 7 ± 2, 7 ± 3 and 6 ± 2 nmol μL−1 min respectively (P = NS). Preservation did not affect the inverse relationship between Na+/H+ antiport activity and intracellular pH. Thus, hepatocellular defence against intracellular acidosis is maintained during up to 48 h in University of Wisconsin solution.

Conclusion

Altered pHi homeostasis is unlikely to play a role in the pathogenesis of primary non‐function of liver allografts.
Tamm–Horsfall protein isolated from urine of pregnant and non‐pregnant women has similar oligosaccharides
Authors: Olczak  , Kubicz  , Kokot  , Duława
Published: March 2003

Background

Differences in the immunosuppressive activity of Tamm–Horsfall protein and uromodulin claimed by many investigators are controversial. They have been ascribed to variations in the carbohydrate moiety.

Methods

We isolated urinary glycoproteins from 18 non‐pregnant (THP) and 12 pregnant (UM) women using the same method (adsorption on diatomaceous earth) and performed comparative studies including monocarbohydrate analysis and tests of reactivity with lectins, cytokines and serum proteins.

Results

No significant differences in monocarbohydrate content or in the reactivity with specific lectins were found between the native urinary glycoproteins or between their proteolytic products. Also, in Sda+ and Sda− donors monitored throughout pregnancy and after delivery, no time‐dependent differences in the sugar moiety were observed. We found that THP/UM from Sda+ donors reacted more strongly with PHA‐L than THP/UM from Sda− donors, providing further evidence for carbohydrate variations between Sda+ and Sda− determinants. No differences between THP and UM in terms of their reactivity with recombitant human interleukin (rhIL) 1α, recombinant human tumour necrosis factor (rhTNF) α and some serum proteins were found, indicating similar biological activity.

Conclusion

The results of our carbohydrate analysis together with previous data on amino acid analysis indicate that Tamm–Horsfall protein and uromodulin are identical or very similar glycoproteins.
Time course of immunological markers in patients with the systemic inflammatory response syndrome: evaluation of sCD14, sVCAM‐1, sELAM‐1, MIP‐1α and TGF‐β2
Authors: Stoiser  , Knapp  , Thalhammer  , Locker  , Kofler  , Hollenstein  , Staudinger  , Wilfing  , Frass  , Burgmann
Published: March 2003

Background

The systemic inflammatory response syndrome (SIRS) is viewed as a system‐wide inflammatory response. Up until now, no parameter has been available for predicting the development of septic shock. In the present study, we evaluated the usefulness of serum levels of CD14, vascular cell adhesion molecule‐1 (VCAM‐1), endothelial leucocyte adhesion molecule‐1 (ELAM‐1), macrophage inflammatory protein (MIP) 1α and transforming growth factor β2 (TGF‐β2) as early markers of outcome in patients with SIRS.

Methods

A group of 28 SIRS patients (13 survivors/15 non‐survivors) was compared with a healthy control group and with patients with local inflammation. Blood samples were analysed on days 0, 4 and 7. Proinflammatory parameters such as sCD14, sVCAM‐1, sELAM‐1, MIP‐1α and anti‐inflammatory parameters such as TGF‐β2 were determined using enzyme‐linked immunosorbent assay (ELISA).

Results

At the beginning, all evaluated proinflammatory immunological parameters with the exception of sVCAM‐1 were significantly increased in patients with SIRS compared with the healthy control group. However, no significant difference could be observed for all immunological parameters comparing survivors and non‐survivors, with the exception of interleukin (IL) 6 at day 7.

Conclusion

All evaluated proinflammatory parameters were increased in patients with SIRS during the course of the disease. However, the parameters have no correlation with outcome and prognosis of SIRS patients.
Haemodynamic effects of 8‐day octreotide and prazosin administration in portal hypertensive rats
Authors: Lin  , Wu  , Huang  , Hou  , Lee  , Hong
Published: March 2003

Background

Octreotide and prazosin are both effective portal hypotensive drugs in the control or prevention of variceal bleeding. The present study was undertaken to investigate the haemodynamic effects of octreotide and prazosin, alone or in combination, in portal hypertensive rats.

Methods

Portal hypertension was induced by partial portal vein ligation. Portal hypertensive rats were allocated into one of the four groups — vehicle group (saline, 0.5 mL 12 h−1), octreotide group (30 μg kg−1 12 h−1), prazosin group (0.4 mg kg−1 12 h−1), and octreotide (30 μg kg−1 12 h−1) plus prazosin (0.4 mg kg−1 12 h−1) group — with eight rats in each group. Prazosin or saline was administered by gavage, whereas octreotide was administered by subcutaneous injection. The drug was given on the day of ligation and continued for 8 consecutive days. Systemic as well as splanchnic haemodynamic parameters were measured thereafter.

Results

Portal vein‐ligated rats exhibited typical hyperdynamic state compared with sham‐operated rats. The portal venous pressure, portal tributary blood flow and cardiac index were significantly reduced by treatment of octreotide, prazosin or octreotide plus prazosin in portal hypertensive rats. Hyperdynamic parameters of systemic, renal and portal territory vascular resistances, and renal as well as hepatic arterial blood flow were ameliorated by treatment of octreotide or octreotide plus prazosin in portal hypertensive rats. Overall, octreotide treatment exerted more beneficial haemodynamic effects than prazosin treatment. The combination of octreotide and prazosin exerted better haemodynamic effects in cardiac index but worse effects in systemic as well as portal territory vascular resistance than octreotide treatment alone.