bluuebunny/crossref_metadata_2025 huggingface dataset:
Pathogenicity and culture studies comparing the Aphanomyces involved in epizootic ulcerative syndrome (EUS) with other similar fungi
Authors: Lilley J H , Roberts R J
Published: November 2003

Pathogenicity and cultural experiments described here provide futher evidence that a distinct species of Aphanomyces is responsible for much of the characteristic pathology of epizootic ulceration syndrome (EUS). Zoospores from 58 fungal isolates were injected intramuscularly in snakehead fish, Channa striata (Bloch). These fungi comprised: Aphanomyces strains isolated from EUS‐affected fish; saprophytic Aphanomyces, Achlya and Saprolegnia spp. from infected waters; and further saprolegniaceous fungi involved in other diseases of aquatic animals. Only the Aphanomyces strains isolated from fish affected by EUS, Australian red spot disease (already considered synonymous with EUS) or mycotic granulomatosis described from Japan were able to grow invasively through the fish muscle and produce the distinctive EUS lesions. In contrast to Aphanomyces astaci Schikora, the EUS‐Aphanomyces was shown to be unable to infect noble crayfish, Astacus astacus L. The snakehead‐pathogenic strains were further distinguished from all the other fungi under comparison by their characteristic temperature‐growth profile and inability to grow on certain selective fungal media.
Nutrition advice in primary care: evaluation of practice nurse nutrition training programmes
Authors: Cadman Lisa , Wiles Rose
Published: November 2003

Primary health care teams (PHCT), including the practice nurse (PN), now have a significant role in health promotion in the UK, which includes the dissemination of advice relating to food and health. However, reports suggest there is a lack of nutritional knowledge among PHCT members and/or problems in communicating dietary advice effectively. Dorset Healthcare Trust employs two full‐time primary care dietitians (PCDs). Their remit is to provide training in the field of nutrition to members of the PHCT, primarily PNs, in order to facilitate their role in delivering effective and consistent healthy eating advice. This small research study was designed to evaluate the impact of nutrition training from a primary care dietitian on the attitudes, practice and knowledge of practice nurses. There have been few studies or reports documenting this, which highlighted the need to evaluate the practice nurse training programmes in Dorset. Five practices of varying size were included in the study. Evaluation was undertaken by means of semi‐structured interviews with one practice nurse from each practice conducted before and after training. In addition a questionnaire was used as a tool to assess perceived nutrition knowledge and confidence when giving dietary advice. True/false statements and a case history formed part of the questionnaire which was completed both pre‐ and post‐training. Three 1‐h training sessions covering the topics of obesity, diabetes mellitus and coronary heart disease were planned. They were presented by the primary care dietitian to each practice nurse together with other members of their PHCT over a 3‐month period. The primary care dietitian collected feedback on each training session in order to monitor teaching methods and presentation skills. The study suggests that dietitian‐led training sessions are well received by PNs and can have an impact on increasing or updating practice nurses» knowledge about diet, particularly where their initial knowledge was low.
Is thirst associated with disability in hospital inpatients?
Authors: Blower A. C.
Published: November 2003

Objectives: The study aimed to determine what factors prevent patients from drinking in hospital. It also investigated whether thirst is associated with disability and how patients obtain drinks.

Methods:Structured interviews with patients and staff were carried out using the Office of Population Censuses and Surveys (OPCS) disability instrument to measure patient's disability. The study took place in an oncology, orthopaedic and general medical ward in three Cardiff hospitals, with 50 patients studied on each ward (150 patients in total). The main outcome measures were thirst score, ease of reaching drinks, waiting before asking for assistance, availability of drinks and help to drink, and disability score.

Results:Fifty‐two per cent (n= 78) of the sample were more thirsty than usual since admission.

Thirty‐seven per cent (n= 56) were not able to drink as often as they needed to. For these patients the causes included: inability to reach the drink (89%) reluctance to ask for help to drink (45%), unavailability of drinks (32%) and unavailability of help to drink (29%). Of the patients who needed help to drink, 94% (n= 33) waited before asking for help, and 91% did so because they did not want to trouble busy staff. Significant associations were found between thirst and various aspects of disability (locomotion, reaching and stretching, dexterity, personal care and continence).

Conclusion: Thirst was common in the sample of inpatients interviewed. Many patients were unable to drink as often as they needed. Inability to reach drinks, reluctance to ask busy staff for help and unavailability of drinks or help to drink were the main reasons for this. Thirst was associated with disability. No causal relationship was proved, but disabled dependant patients rely on the availability of drinks within reach and help to drink. Lack of these provisions may be important factors contributing to thirst in disabled inpatients.
Pancreatic enzyme supplements and vitamins in cystic fibrosis
Authors: Leonard C. H. , Knox A. J.
Published: November 2003

The management of pancreatic insufficiency and the maintenance of satisfactory fat‐soluble vitamin status are major issues in the nutritional management of cystic fibrosis (CF). This article discusses the pancreatic enzyme replacement preparations currently used in the United Kingdom. It also provides an overview of the importance of fat‐soluble vitamins in CF, the supplements currently used, and assesses where future research might be directed. We conclude that dietitians play an important role in helping CF patients to achieve optimal growth and nutritional status, and should therefore be involved in management from diagnosis. Monitoring of pancreatic enzyme replacement therapy (PERT) and vitamin therapy is an integral part of the dietetic assessment, and should be carried out on a regular basis to ensure optimal nutritional management for each individual. Future research needs to concentrate on the efficacy and safety of high lipase enzyme preparations. Research is required to assess the absorption, metabolism and losses of fat‐soluble vitamins amongst today's CF population, and to determine requirements according to age group.
Incidence of rare systemic rheumatic and connective tissue diseases in Finland
Authors: KAIPIAINEN‐SEPPÄNEN OILI , AHO KIMMO
Published: November 2003

Objective. To obtain information on the incidence of rare systemic rheumatic and connective tissue diseases in Finland.

Design. Population‐based epidemiological study.

Setting. Five out of 21 central hospital districts in Finland (population: about 1 million adults 16 years of age).

Subjects. Subjects entitled under the nationwide sickness insurance scheme to receive specially reimbursed medication for rare systemic rheumatic or connective tissue diseases in 1990.

Main outcome measure. Incidence.

Results. A total of 30 incident cases occurred. Nine patients had mixed connective tissue disease, four had systemic sclerosis, four had dermato/polymyositis and one patient had inclusion body myositis; the corresponding annual incidence rates were 8, 4, 4 and 1/million of the adult population. Only one patient had adult Still's disease. The overall annual incidence rate of systemic vasculitides was 9/million of the adult population.

Conclusion. This study provides population‐based figures on the incidence of rare systemic rheumatic and connective tissue diseases in Finland.
Continuous vectorcardiographic changes in relation to scintigraphic signs of reperfusion in patients with acute myocardial infarction receiving thrombolytic therapy
Authors: JUHLIN P. , BOSTRÖM P.‐Å. , HANSEN O. , FREITAG M. , ERHARDT L. , DIEMER H. , LILJA B.
Published: November 2003

Objectives. Changes in the electrical activity of the heart reflecting the infarct process can be recorded by continuous vector‐ECG, a method which is now clinically available for cardiac supervision. Shifts of the ST‐segment and QRS‐vector reflect ischaemia and necrosis of the myocardium. Continuous vector‐ECG changes were evaluated against myocardial scintigraphy in 18 patients with acute myocardial infarction treated with streptokinase in order to study the impact of improved myocardial perfusion.

Design. Myocardial perfusion was analysed with 99Tcm‐Sestamibi (Cardiolite, DuPont Scandinavia AB, Kista, Sweden) single photon emission computerized tomography (SPECT). Registrations were performed before and after thrombolysis in order to estimate the amount of myocardium with impaired perfusion initially (threatened myocardium) and the degree of perfusion improvement in this myocardial area. X, Y, Z vectors were registered continuously by Frank leads (Ortivus Medical, Täby, Sweden). QRS‐vector difference, and the time to plateau phase and the ST‐vector magnitude were used as a measurement of ischaemia and size of the myocardial infarction.

Results. In seven out of 11 patients treated within 3 h of onset of symptoms, an improvement in myocardial perfusion in the initially hypoperfused areas was achieved in contrast to none of the seven patients treated >3 h after onset of pain (P<0.05). In the whole patient material, there was a negative correlation between the time to plateau level for the QRS‐vector and the improvement in myocardial perfusion (r=‐0.53, P<0.05). Among patients treated within 3 h, there was a negative correlation between the plateau level for the QRS‐vector magnitude compared to the improvement in myocardial perfusion (r=‐0.61, P<0.05) and a negative correlation between the plateau level and the myocardial perfusion level after therapy (r=‐0.69, P<0.05). In these patients, there were also negative correlations between the maximal ST‐vector magnitude and the myocardial perfusion both before and after thrombolysis (r=‐0.81, P<0.05 and r=‐61, P<0.05, respectively).

Conclusion. Patients with marked improvement in myocardial perfusion indicating successful thrombolysis reach their plateau levels of the QRS‐change faster and have lower total QRS‐vector differences than patients without successful thrombolysis as reflected by myocardial scintigraphy. Patients with a high ST‐vector magnitude have low perfusion levels both before and after therapy indicating a pronounced ischaemic damage of the myocardium. Thus, VCG‐changes reflect impairment in myocardial perfusion during acute myocardial infarction.
Serum lipids and lipoproteins are correlated to skin vessel reactivity in healthy women
Authors: ALGOTSSON A.
Published: November 2003

Objectives. To investigate whether serum lipids and lipoproteins are correlated to the results of skin vessel reactivity tests.

Design. Healthy, non‐smoking individuals of various ages without atopic constitution and medication were selected for the study.

Setting. Subjects blood sampled and examined with iontophoresis and a newly developed laser Doppler perfusion imager at Huddinge University Hospital.

Subjects. Thirteen men, 20–80 years of age, and 21 women, 18–76 years of age, who fulfilled the inclusion criteria.

Main outcome measures. Normalized perfusion values (%) after iontophoresis of acetylcholine (ACh), nitroprusside and isoprenaline. Fasting concentrations of total cholesterol, high‐density lipoprotein cholesterol and triglyceride values.

Results. Skin vessel reactivity tests to ACh and isoprenaline, and to a lesser extent, nitroprusside were positively correlated to high‐density lipoprotein cholesterol (HDL‐C) levels (P=0.014, 0.005 and 0.113, respectively), and negatively correlated to both the ratio of total cholesterol/HDL‐C (P=0.029, 0.011, 0.005) and the level of triglycerides (P= 0.045, 0.011, 0.005) in young and middle‐aged women. There was also a negative correlation between isoprenaline and triglycerides (P=0.042) in elderly women. No correlations between serum lipids and lipoproteins and skin vessel reactivity were found in men.

Conclusions. The results of the study suggest that serum lipids and lipoproteins, primarily HDL‐C, influence skin vessel reactivity in healthy women. Furthermore, HDL‐C seems to influence the function of the vascular smooth muscle as well as the endothelium.
Polyarteritis nodosa: ischaemic intestinal pain successfully treated with nitroglycerin
Authors: DAHLANDER B. , ODEBERG H. , HANSEN B. U.
Published: November 2003

Inflammation of medium and small sized arteries caused by polyarteritis nodosa (PAN) sometimes causes acute and life threatening ischaemic intestinal complications. We report a case of PAN presenting with severe abdominal pain successfully treated with nitroglycerin.
Brain abscesses: the lung connection
Authors: FINKELSTEIN R. , ENGEL A. , SIMRI W. , HEMLI J. A.
Published: November 2003

Pulmonary arteriovenous fistulas are uncommon abnormalities of capillary development which cause right to left shunting and, if not treated, may lead to severe neurological complications, including meningitis and brain abscess. Pulmonary arteriovenous fistulas are commonly a result of hereditary haemorrhagic telangiectasia (Rendu–Osler–Weber disease) and both conditions may be readily diagnosed by careful history taking and physical examination. Two cases of brain abscess associated with hereditary haemorrhagic telangiectasia, which remained unrecognized for many years, are reported. These cases emphasize the importance of early diagnosis and treatment of pulmonary arteriovenous fistula in preventing central nervous system infections.
Assessment of autonomic nerve function in acute intermittent porphyria; a study based on spectral analysis of heart rate variability
Authors: BLOM H. , ANDERSSON C. , OLOFSSON B.‐O. , BJERLE P. , WIKLUND U. , LITHNER F.
Published: November 2003

Objectives. To assess the function of the autonomic nervous system in patients with acute intermittent porphyria by spectral analysis of the heart rate variability.

Design. A cross‐sectional case–control study.

Setting. Patients were examined at the Primary Health Care Centre, Arjeplog and at Umeå University Hospital, where the controls were also examined.

Subjects. Twenty‐three patients with acute intermittent porphyria verified by DNA analysis and 92 healthy controls were included.

Main outcome measures. The mid‐frequency band power after tilting was used to evaluate sympathetic function, and the high frequency band power during controlled breathing at 12 breaths min‐1 and the mid‐frequency band power during controlled deep breathing at 6 breaths min‐1 were used to evaluate parasympathetic function.

Results. There was no evidence of sympathetic dysfunction in the patients. The mid‐frequency band power during controlled deep breathing at 6 breaths min‐1 was significantly (P=0.02) lower in the patient group.

Conclusions. Our findings indicate a parasympathetic dysfunction in patients with acute intermittent porphyria. This may be causally related to sudden cardiac death and the life‐threatening arrhythmias which have been observed in this disorder.
Reproducibility of on‐line vectorcardiography measurements in patients with and without acute ischaemic heart disease
Authors: LUNDIN P. , JENSEN J. , ERIKSSON SV
Published: November 2003

Lundin P, Jensen J, Eriksson SV (Department of Medicine, Danderyd Hospital, Danderyd, Sweden, and Department of Medicine, Huddinge Hospital, Stockholm, Sweden). Reproducibility of on‐line vectorcardiography measurements in patients with and without acute ischaemic heart disease. J Intern Med 1997; 242: 117–24.

Objectives

The aim of the present study was to determine inter and intraobserver variations of measurements with on‐line vectorcardiography (VCG).

Design

The VCG registrations were evaluated by two independent observers. One observer also evaluated the VCG registrations on two separate occasions. Monitored VCG variables were: ST vector magnitude (ST‐VM), ST vector lead X (ST‐X), ST change vector magnitude (STC‐VM) and QRS vector difference (QRS‐VD).

Subjects

: On‐line VCG was performed for 24 hours in 60 patients (10 with low probability of ischaemic heart disease, 25 with unstable angina pectoris and 25 with acute myocardial infarction).

Results

A close correlation between the two observers and small coefficients of variation were found regarding the ST‐VM initial value (r= 0.99, 4.7), the ST‐X maximum depression (r= 0.99, 3.2) and the QRS‐VD end value (r= 0.98, 5.6). A less close correlation and higher coefficients of variation were found regarding the number of QRS‐VD episodes (r= 0.94, 41.5), ST‐VM episodes (r= 0.89, 37.8) and STC‐VM episodes (r= 0.87, 35.1). Correlation coefficients and coefficients of variations for VCG measurements performed on two separate occasions by one observer ranged from 0.97 to 0.99 and from 18.1 to 1.8 respectively. Three (12%) of 25 patients with acute myocardial infarction did not meet the VCG infarction criterion (QRS‐VD ≥ 15 μVs) by both observers. In addition, five (20%) of the 25 patients with unstable angina pectoris met the VCG infarction criterion by both observers.

Conclusion

The inter and intraobserver variation for VCG interpretations was low, but the number of QRS‐VD, ST‐VM and STC‐VM episodes varied between the two observers. This finding suggests that additional training may improve the results. Caution is also recommended in using VCG to rule out or establish the diagnosis of acute myocardial infarction.
Impact of liver transplantation on autonomic neuropathy in familial amyloidotic polyneuropathy: an evaluation by spectral analysis of heart rate variability
Authors: SUHR O. B. , WIKLUND U. , ANDO Y. , ANDO E. , OLOFSSON B.‐O.
Published: November 2003

Suhr OB, Wiklund U, Ando Y, Ando E & Olofsson B‐O (Umeå University Hospital, Umeå, Sweden). Impact of liver transplantation on autonomic neuropathy in familial amyloidotic polyneuropathy: an evaluation by spectral analysis of heart rate variability. J Intern Med 1997; 242: 225–9.

Objectives

To evaluate the impact of liver transplantation on familial amyloidotic polyneuropathy type I (FAP) patients' autonomic neuropathy.

Design

An open study.

Setting

A tertiary referral centre.

Subjects

Twelve liver‐transplanted FAP patients evaluated before and one year or longer after liver transplantation.

Interventions

Spectral analysis of heart rate variability. The low‐frequency band after tilting (sympathetic), and the high‐frequency band in supine position (parasympathetic) were analysed, as were the pulse and blood pressure reaction to tilting. Clinical symptoms related to autonomic disturbances were recorded.

Main outcome measures

Spectral band power for sympathetic and parasympathetic activity.

Results

No statistically significant improvements in sympathetic or parasympathetic band power after liver transplantation was found (sympathetic band power: 2.7 (2.2–3.2) before, 2.9 (2.2–3.6) after; parasympathetic 2.0 (1.6–2.4) before and 2.0 (1.7–2.3) after. A significant correlation was noted between orthostatic blood pressure reaction and sympathetic activity before transplantation, but not after the operation. A trend was noted for improved orthostatic blood pressure reaction. Symptomatic improvements in bowel function and orthostatic symptoms were reported by several patients.

Conclusions.

Although improvements in autonomic symptoms are reported after liver transplantation, no significant improvement is noted in sympathetic or parasympathetic spectral band power of heart rate variability. However, the follow‐up period of 17 months may be too short. Further evaluation after an additional two and four years is needed.
The accuracy of peripheral skeletal assessment at the radius in estimating femoral bone density as measured by dual‐energy X‐ray absorptiometry: a comparative study of single‐photon absorptiometry and computed tomography
Authors: BOONEN S. , CHENG X. , NICHOLSON P. H. F. , VERBEKE G. , BROOS P. , DEQUEKER J.
Published: November 2003

Boonen S, Cheng X, Nicholson PHF, Verbeke G, Broos P, Dequeker J (Katholieke Universiteit Leuven, Leuven, Belgium). The accuracy of peripheral skeletal assessment at the radius in estimating femoral bone density as measured by dual‐energy X‐ray absorptiometry: a comparative study of single‐photon absorptiometry and computed tomography. J Intern Med 1997; 242: 323–8.

Objectives

One of the latest developments in bone densitometry is peripheral quantitative computed tomography (pQCT), a method which allows the separate determination of cortical and trabecular bone mineral density (BMD) in the peripheral skeleton. This study was designed to compare the relative abilities of single‐photon absorptiometry (SPA) and pQCT to reflect BMD of the proximal femur as measured by dual‐energy X‐ray absorptiometry (DXA), an established predictor of osteoporotic hip fracture risk.

Design

Cross‐sectional study.

Subjects

A well‐defined community‐based sample of 129 skeletally healthy women aged 70–87 years.

Measurements

Radial BMD by SPA and pQCT and femoral BMD by DXA. Univariate and multivariate regression analyses were performed relating the DXA measurements at the femoral neck and the trochanteric region with the values of SPA and pQCT.

Results

Approximately 38% of the variance in femoral neck BMD could be explained by BMD of the midradius assessed by SPA, in contrast to only 18–27% by pQCT. At the trochanter, 32% of BMD could be predicted by SPA as compared to 19–26% by pQCT. Moreover, according to multiple regression, prediction of femoral BMD by SPA was not enhanced by performing pQCT.

Conclusions

Radial pQCT has little value as a screening tool to identify elderly women with low femoral BMD. Additional research is needed to determine whether or not pQCT will enhance fracture prediction beyond that obtainable from a density measurement by SPA.
Visceral fat accumulation as an important risk factor for obstructive sleep apnoea syndrome in obese subjects
Authors: SHINOHARA E. , KIHARA S. , YAMASHITA S. , YAMANE M. , NISHIDA M. , ARAI T. , KOTANI K. , NAKAMURA T. , TAKEMURA K. , MATSUZAWA Y.
Published: November 2003

Objectives. It is well known that obstructive sleep apnoea (OSA) is frequently associated with obesity. In the current study, we investigated the correlation between abdominal visceral fat accumulation and the presence of OSA in obese subjects.

Subjects. A consecutive series of 37 patients (17 men and 20 women) with primary obesity who were admitted to the Second Department of Internal Medicine, Osaka University Hospital, were investigated. Patients with OSA were designated as those whose apnoea index (number of apnoea h−1 of sleep) was more than 5.

Main outcome measures. The distribution of body fat was determined using computed tomographic sections. The upper airway dimensions were evaluated with indices obtained by cephalometry in both inspiratory and expiratory phases.

Results. Visceral adipose tissue (AT) area which was measured at the level of the umbilicus, and its ratio to total AT area were both significantly greater in OSA patients as compared with those in non‐OSA patients. All subjects whose visceral AT area measured more than 220 cm2 manifested OSA. These two parameters also closely correlated with an increase in apnoea index. A multiple linear regression analysis revealed that the visceral AT area significantly correlated to apnoea index when age, AT mass and lean body mass were taken into account. The fluctuations of the upper airway were significantly greater in the large visceral fat group than in the small visceral fat group.

Conclusions. These results suggest that visceral fat accumulation is an important risk indicator for OSA in obese subjects.
The treatment of oesophageal varices: a debate and a discussion
Authors: CONN H. O. , LEBREC D. , TERBLANCHE J.
Published: November 2003

At the Biennial Meeting of the International Association for the Study of the Liver, in Cape Town, South Africa, 20–24 February 1996, the treatment of oesophageal varices was selected as a subject for the discussion of controversies in portal hypertension. This review gives a summary of that discussion.

Dr Didier LeBrec gave a broad overview of the medical management of oesophageal varices by presenting a list of 52 pharmacological agents that reduce portal venous pressure and presented the advantages and disadvantages of each. He emphasized that recent randomized clinical trials (RCT) have demonstrated that propranolol delays and decreases the occurrence of haemorrhage from varices in patients who have not previously suffered such complications. He also reported that isosorbide‐mononitrate is equally effective and further enhances the effect of propranolol. He also reported that the effects of propranolol plus endoscopic sclerotherapy (EST) were more effective than EST alone in preventing haemorrhage, but not in improving survival. Finally he noted that propranolol in high dosage did not prevent the development of large varices in cirrhotic patients with small or undetectable varices.

Dr John Terblanche compared the efficacy of EST and endoscopic ligation of varices (ELV) and reported that all four RCTs found ELV to be superior. He discussed portacaval anastomosis (PCA) and concluded that only emergency PCA as reported by Orloff, is thought to be truly beneficial, and suggested that EST, plus ELV may be the treatment of choice.

Dr Harold O. Conn, who served as the moderator of this session summarized the presentations and pointed out that liver transplantation is the most effective form of therapy of all, albeit extremely complex and expensive. He discussed transjugular intrahepatic portosystemic shunts (TIPS), the newest form of therapy, and emphasized its virtues (immediate reduction of portal venous pressure) and its limitations (frequent portosystemic encephalopathy and frequent spontaneous stenoses). He presented a brief discussion of the prevention of the development of the varices themselves, currently termed ‘pre‐primary prophylaxis’, a hope for the future. He ended with ‘Predictions’ which if proven correct will give a preview of portal hypertension in the 21st century.
Determination of the size distribution of lecithin liposomes: a comparative study using freeze fracture, cryoelectron microscopy and dynamic light scattering
Authors: Egelhaaf S. U. , Wehrli E. , Müller M. , Adrian M. , Schurtenberger P.
Published: November 2003

The size distribution of liposomes is often determined using freeze fracture, cryoelectron microscopy or dynamic light scattering. However, the resulting size distributions do not directly coincide owing to the different weighting of the techniques. We present several methods which correct for these effects and allow a comparison of liposome size distributions as obtained by freeze fracture, cryoelectron microscopy or dynamic light scattering. These methods are based on theoretical models for the weighting of the size distribution of liposomes, which result from the preparation procedure for freeze fracture electron microscopy and from the measurement by dynamic light scattering. The proposed transformation methods are then experimentally tested with a sample of lecithin liposomes, whose size distribution was determined by dynamic light scattering, freeze fracture and cryoelectron microscopy. Furthermore, the weaknesses of the experimental techniques and hence of the resulting size distributions are discussed.
Imaging of RNA in situ hybridization by atomic force microscopy
Authors: KALLE W. H. J. , MACVILLE M. V. E. , VAN DE CORPUT M. P. C. , DE GROOTH B. G. , TANKE H. J. , RAAP A. K.
Published: November 2003

In this study we investigated the possibility of imaging internal cellular molecules after cytochemical detection with atomic force microscopy (AFM). To this end, rat 9G and HeLa cells were hybridized with haptenized probes for 28S ribosomal RNA, human elongation factor mRNA and cytomegalovirus immediate early antigen mRNA. The haptenized hybrids were subsequently detected with a peroxidase‐labelled antibody and visualized with 3,3′‐diaminobenzidine (DAB). The influence of various scanning conditions on cell morphology and visibility of the signal was investigated. In order to determine the influence of ethanol dehydration on cellular structure and visibility of the DAB precipitate, cells were kept in phosphate‐buffered saline (PBS) and scanned under fluid after DAB development or dehydrated and subsequently scanned dry or submerged in PBS. Direct information on the increase in height of cellular structures because of internally precipitated DAB and the height of mock‐hybridized cells was available. Results show that internal DAB precipitate can be detected by AFM, with the highest sensitivity in the case of dry cells. Although a relatively large amount of DAB had to be precipitated inside the cell before it was visible by AFM, the resolution of AFM for imaging of RNA–in situ hybridization signals was slightly better than that of conventional optical microscopy. Furthermore, it is concluded that dehydration of the cells has irreversible effects on cellular structure. Therefore, scanning under fluid of previously dehydrated samples cannot be considered as a good representation of the situation before dehydration.
Estimation of mean particle size from single sections
Authors: KARLSSON L. M. , CRUZ‐ORIVE L. M.
Published: November 2003

The usual size descriptors for three‐dimensional (3D) particles are volume (V), surface area (S) and, to a lesser extent, mean height (H), the mean being over isotropic directions in space. With these parameters we can construct 12 weighted means for the particle population, namely {EY(X), X=HSVY=NHSV}, where EY(X) represents the population mean of the parameter X weighted by the parameter Y. The ordinary means are the number‐weighted ones, namely {EN(X), X=HSV}, whose estimation is only possible using a 3D probe (notably the disector) to sample the particles. In this paper we describe a general strategy to estimate EY(X) and consider in detail the estimation of ES(V) and EV(S); unbiased estimators have been proposed for both weighted means from single or independent sections, but to our knowledge the corresponding sampling and estimation procedures have not yet been illustrated with real data. We do this here for the tungsten particles in a cemented carbide.
Statistical analysis of the distribution of gold particles over antigen sites after immunogold labelling
Authors: GLASBEY C. A. , ROBERTS I. M.
Published: November 2003

The locations of immunogold‐labelled particles on ultrathin sections of pellets of purified tobacco rattle virus were analysed statistically. The distributions were found to be inconsistent with a Poisson process. Instead, a physically based model, a modified Poisson process, is proposed and shown to fit the data well. The antigen sites to which antibodies are attached are assumed to follow a Poisson process and one gold particle sits on top of each site. However, if two sites are closer than a threshold then the physical size of the gold particles with attached antibodies pushes the particles apart, and if sites are nearer than a higher threshold there is a chance that surface tension will pull the gold particles together.
Visualization of the cytoskeleton within the secondary vascular system of hardwood species
Authors: Chaffey N. J. , Barnett J. R. , Barlow P. W.
Published: November 2003

A single fixation technique has been devised to demonstrate localization of α‐tubulin (for microtubules) and F‐actin (for microfilaments) within the secondary vascular system of hardwood trees by indirect immunofluorescence microscopy using butyl‐methylmethacrylate‐embedded material. Application of this technique to problems of cytomorphogenesis during secondary growth and its versatility are demonstrated with the hardwood species Aesculus hippocastanum L., Salix viminalis L., S. burjatica Nazarov × S. viminalis L., Hedera helix L., Acer platanoides L., Platanus sp., Quercus ilex L. and Liriodendron tulipifera L., and in the softwood Pinus pinea L. The methods employed have considerable scope for advancing knowledge of the role of the cytoskeleton in differentiation within the secondary vascular system of woody species.
Reproducibility and accuracy of interactive segmentation procedures for image analysis in cytology
Authors: Einstein A. J. , Gil J. , Wallenstein S. , Bodian C. A. , Sanchez M. , Burstein D. E. , Wu H.‐S. , Liu Z.
Published: November 2003

The segmentation of nuclear images is a crucial step in the development of procedures using image analysis for the cytological diagnosis of cancer. The purpose of this study is to evaluate the reproducibility and accuracy of several interactive segmentation methods which can be used in this context. Four methods were studied: a thresholding‐based method enabling selection of intensity histogram contrast and brightness, manual tracing with a stylus, and arc‐ and ellipse‐fitting routines. Features of nuclear size and shape were derived from nuclei segmented on repeated occasions by several individuals. Variance component models provided a statistical framework for evaluating the intraobserver and interobserver variability of these measurements in terms of their intraclass correlation coefficients. Of the methods tested, the arc‐fitting segmentation method gave the most reproducible results, and thresholding the least. Reproducibility was generally very high both between individuals and for repeated segmentations by a single individual. Accuracies of area measurements for the various methods, as determined with respect to point counting, paralleled the reproducibilities of the methods. Sample size requirements were observed to be more dependent on the biological variability of the tissue sampled than on the particular segmentation method or on the number of individuals performing segmentation.
Spider major ampullate silk (drag line): smart composite processing based on imperfect crystals
Authors: THIEL B. L. , VINEY C.
Published: November 2003

A spider can spin major ampullate silk (drag line) at rates that differ by more than an order of magnitude, and yet obtain consistently reliable tensile properties. Silk samples collected at different rates and stained by infiltration with tin were studied by transmission electron microscopy. The stained microstructures indicate the presence of nonperiodic lattice crystals, the average size of which depends on the silking rate. A simple statistical point model demonstrates that the ordered regions in major ampullate silk can originate from statistical matches between adjacent chains. The minimum size of the ordered regions is dictated by the fixed monomer sequence in the chains and not by processing kinetics. Inductively coupled plasma—mass spectroscopy shows that the concentration of multivalent protein‐binding cations in the unstained fibre is significantly reduced at the higher rates of silking, compared with their concentration at the lowest rates. Qualitatively, this result is consistent with the ions being used to maintain the shear sensitivity of silk secretion over the range of processing rates studied.
Anterior Pituitary Release of Prolactin is Inhibited by Exposure to Short Photoperiod
Authors: Badura Lori L. , Goldman Bruce D.
Published: November 2003

The potential regulatory sites responsible for the decrease of circulating prolactin (PRL) levels shown by many photoperiodic mammals following prolonged exposure to short days was investigated in Siberian hamsters that had been maintained under a stimulatory, long‐day photoperiod, and in hamsters that had been shifted to a nonstimulatory, short‐day photoperiod for 8–10 weeks. The ability of anterior pituitary fragments (AP) from each of these groups to release prolactin was evaluated in pituitary tissue cultured alone and also in pituitary tissue co‐cultured with hypothalamic fragments (HF), using a perifusion tissue culture system. The perfusate from these cultures was collected every 1/2 h for 8 h, and was assayed for basal levels of prolactin using radioimmunoassay. For AP tissue cultured alone, there was a robust reduction in prolactin release by the fragments harvested from short‐day housed animals. In AP tissue harvested from long‐day exposed animals, co‐culture with either long‐ or short‐day HF did not induce significant changes in basal PRL release. Similarly, co‐culture with short‐day HF did not significantly alter PRL release in short‐day APs. However, there was a significant increase in release when short‐day APs were co‐cultured with long‐day HF. These results suggest a direct effect of photoperiod on PRL synthesis and/or release at the level of the pituitary. However, the altered responsiveness of short‐day pituitaries could be the result of previous, chronic inhibitory hypothalamic input during short‐day exposure. A follow‐up study was conducted to investigate the ability of vasoactive intestinal peptide (VIP) to stimulate PRL release from long‐ and short‐day APs. Results indicated that the ability of VIP to stimulate PRL release is both photoperiod and dose dependent.
The Milk‐Ejection Reflex in the Peri‐Partum Rat: Effects of Oestradiol and Progesterone on Basal Milk‐Ejection Frequency and the Facilitatory Response to Central Oxytocin
Authors: Jiang Q. , Wakerley J. B.
Published: November 2003

Experiments were undertaken to examine the effects of ovarian steroids on the functional characteristics of the milk‐ejection reflex during late pregnancy. Basal milk‐ejection frequency and response to i.c.v. oxytocin (OT) were compared in different experimental groups, using intramammary pressure recordings obtained in suckling tests under urethane anaesthesia. Ovariectomy (OVX) on day 20 of pregnancy significantly (P<0.05) increased milk‐ejection frequency on day 22, compared with sham‐OVXed animals. I.c.v. injection of 2.2 ng OT during suckling had no consistent effect on milk ejection in either of these groups. Pretreatment with oestradiol (5 μg per day, s.c.) or progesterone (5 mg per day, s.c.) both resulted in a fall in milk‐ejection frequency compared to oil‐treated OVXed controls. However, whereas oestradiol‐treated OVXed rats showed a facilitatory response to i.c.v. OT, with a significant (P<0.05) increase in milk‐ejection frequency in the 20 min period after injection, progesterone‐treated OVXed rats showed only a delayed decrease in milk‐ejection frequency (significant at P<0.05 between 20–40 min after injection). Oil‐treated OVXed rats showed no significant response to i.c.v. OT at any stage. Electrophysiological recordings from supraoptic OT neurones confirmed that bursting activity was increased by i.c.v. injection of OT in oestradiol‐treated, but not progesterone‐treated rats. Further experiments with hysterectomized ovariectomized rats indicated that the difference in response to i.c.v. OT in oestradiol‐ vs progesterone‐treated rats was not related to changes in the timing of birth induced by steroid treatments. These findings demonstrate the ability of ovarian steroids to alter the characteristics of the milk‐ejection reflex in the peri‐partum rat. In particular, the rise in oestradiol and fall in progestesterone near term, may contribute to programming of the facilitary response to central OT in preparation for lactation.
Differential Distribution of Thyroid Hormone Receptor Isoform in Rat Dorsal Root Ganglia and Sciatic Nerve in vivo and in vitro
Authors: Glauser L. , Barakat Walter I.
Published: November 2003

Using autoradiographic techniques carried out under precise conditions we previously demonstrated that both sensory neurons and peripheral glial cells in dorsal root ganglia (DRG) or sciatic nerve, possess specific []> 125I]‐labeled T3 binding sites. Thyroid hormone receptors (TR) include several isoforms (TRα1, TRα2, TRβ1, TRβ2...) The present study demonstrates that while sensory neurons and peripheral glial cells both possess functional TR, they express a differential expression of TR isoforms.
Unchanged Amounts of Vasopressin mRNA in the Supraoptic and Paraventricular Nucleus during Aging and in Alzheimer’s Disease
Authors: Lucassen P. J. , Van Heerikhuize J. J. , Guldenaar S. E. F. , Pool C. W. , Hofman M. A. , Swaab D. F.
Published: November 2003

The paraventricular (PVN) and supraoptic nucleus (SON) demonstrate a striking stability with respect to cell numbers during aging and Alzheimer’s disease (AD). Vasopressin (AVP) neurons even become activated during aging as judged from several parameters for neuronal activity, such as increased AVP plasma levels, enlarged nucleolar as well as cell size and an increased size of the Golgi apparatus in AVP‐neurons. The activation possibly occurs as compensation for an age‐related loss of AVP‐receptors in the kidney. As a specific marker for AVP synthesis, we used quantitative in situ hybridization and estimated total amounts of AVP‐mRNA in the entire SON and PVN of 14 control subjects and 14 AD patients that were matched for age, fixation time, postmortem delay and storage time of the tissue in paraffin. Following quantification, no differences were observed in total amounts of AVP‐mRNA in the SON or PVN between young and old controls or between young and old AD patients, nor between the entire group of controls and AD patients. A significant negative correlation was found between the volume of the AVP‐mRNA signal in the AD SON and age while the total amount of mRNA remained the same. This suggests a redistribution of cells or cell compartments in aging. A significant positive relation in both SON and PVN of AD patients was found between storage time of the paraffin‐embedded tissue and the total amount of AVP‐mRNA. A significant positive relation was present in the PVN, but not SON between pH of the cerebrospinal fluid, which is a marker for agonal state and the total amount of AVP mRNA. The present unchanged AVP‐mRNA levels in SON and PVN confirm earlier observations on the stability of cell numbers in these nuclei in aging and AD. Although on the basis of other parameters, AVP‐mRNA upregulation was expected, gradual, chronic stimulation over prolonged periods of time may, possibly, induce alternative mechanisms of regulation such as changes in translatability or in mRNA stability.
Effect of pulsed electromagnetic fields on maturation of regenerate bone in a rabbit limb lengthening model
Authors: Taylor Kenneth F. , Inoue Nozumu , Rafiee Bahman , Tis John E. , McHale Kathleen A. , Chao Edmund Y.S.
Published: November 2003

To study the effect of applying pulsed electromagnetic fields (PEMF) during the consolidation phase of limb lengthening, a mid‐tibial osteotomy was performed in 18 adult New Zealand White rabbits and an external fixator was applied anteromedially. Animals were randomly assigned to treatment and control groups. After a 7‐day latency period, the tibiae were distracted 0.5 mm every 12 h for 10 days. The treatment group received a 20‐day course of PEMF for 60 min daily, coinciding with initiation of the consolidation phase. The control group received sham PEMF. Radiographs were performed weekly after distraction. Animals were euthanized 3 weeks after the end of distraction. Radiographic analysis revealed no significant difference in regenerate callus area between treatment and control tibiae immediately after distraction, at 1 week, 2 weeks, or 3 weeks after distraction ( p = 0.71, 0.22, 0.44, and 0.50, respectively). There was also no significant difference in percent callus mineralization ( p = 0.96, 0.69, 0.99, and 0.99, respectively). There was no significant difference between groups with respect to structural stiffness ( p = 0.80) or maximal torque to failure ( p = 0.62). However, there was a significant positive difference in mineral apposition rate between groups during the interval 1–2 weeks post‐distraction ( p < 0.05). This difference was no longer evident by the interval 2–3 weeks post‐distraction. While PEMF applied during the consolidation phase of limb lengthening did not appear to have a positive effect on bone regenerate, it increased osteoblastic activity in the cortical bone adjacent to the distraction site. Since the same PEMF signal was reported to be beneficial in the rabbit distraction osteogenesis when applied during distraction phase and consolidation phase, application of PEMF in the early phase may be more effective. Further work is necessary to determine optimal timing of the PEMF stimulation during distraction osteogenesis. © 2005 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res
Slow sleep oscillation, rhythmic K‐complexes, and their paroxysmal developments
Authors: Steriade M. , Amzica F.
Published: November 2003

This paper presents the relations between the slow (< 1 Hz) oscillation (characterizing the activity of corticothalamic networks during quiescent sleep in cats and humans), sleep K‐complexes, and some paroxysmal developments of sleep patterns. At the cellular level, the slow oscillation is built up by rhythmic membrane depolarizations and hyperpolarizations of cortical neurons. The EEG expression of this activity is marked by periodic K‐complexes which reflect neuronal excitation. The slow oscillation triggers, groups and synchronizes other sleep rhythms, such as thalamically generated spindles as well as thalamically and cortically generated delta oscillations. We discuss the distinctness of the slow (< 1 Hz) and delta (1–4 Hz) oscillations. We also show that the slow cortical oscillation underlies the onset of spike‐wave seizures during sleep by transforming the periodic K‐complexes into recurrent paroxysmal spike‐wave complexes.
Effectiveness of problems used in problem‐based learning
Authors: Mpofu D J S , Das M , Murdoch J C , Lanphear J H
Published: November 2003

Where problem‐based learning (PBL) is the main method used in medical curricula, the literature suggests that it is crucial that the problems used are effective in facilitating students to identify relevant learning issues. These learning issues guide the students' studying. The present investigation explores the extent to which students identify relevant issues following exposure to prepared paper problems. In the preparatory year, in an Introduction to Medicine module, four groups of students were exposed to six themes (Health Care System, Environment and Health, Alternative and Islamic Medicine, Chronic Illness, Infectious Diseases, and Prevention and Health Promotion). Each group had two facilitators per theme. Having discussed the prepared problems, the students identified learning issues which were collected for the purpose of the study. Two content experts, using a Likert scale, analysed learning issues for their concordance to staff objectives per theme. Kappa coefficients were computed for the six PBL themes in order to assess inter‐rater agreement. Learning issues identified as having no relationship to theme objectives were further analysed for their relevance to theme objectives. No objective was totally omitted by any student group. There was a 100% concordance of objectives to learning issues demonstrated over four themes. The relationship of learning issues to theme objectives ranged from 55–85% in the theme on health care system, and 73–94% in the theme on environment and health. Irrelevant learning issues were identified in the first two PBL themes addressed. Kappa coefficients over the six PBL themes varied from 0·49 to 0·82.