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Notes: The fetal heart rates of 340 normal singleton pregnancies at 30–33 weeks gestation were screened using a microprocessor system on-line. Eleven fetuses (3·2%) with a heart rate variation less than the 5th centile were identified, of whom 10 were studied longitudinally. At 30–33 weeks the mean minute range of pulse intervals (a measure of fetal heart rate variation) was 314 (SE 1·5) ms compared with 51·0 (SE 3·4) ms in a randomly selected control group. The study group continued to have significantly lower fetal heart rate variation than controls on each of three subsequent occasions until delivery. There were no significant differences between the two groups in fetal outcome, which was good. This demonstrates that a small proportion of normal fetuses have consistently low heart rate variation, and helps to define the lower limit of the normal distribution of fetal heart rate variation. After delivery, there were no significant differences between heart rate or its variation between the two groups. We conclude that the lower prenatal heart rate variation in the study group was a consequence of the uterine environment.

Notes: Summary. Three groups of women were delivered by caesarean section before labour: for an abnormal fetal heart rate (FHR) trace (21 cases, group 1), or for maternal deterioration in severe pre-eclampsia without gross fetal heart rate abnormalities (20 cases, group 2), or to avoid mechanical difficulties in labour at term (30 cases, group 3). The mean gestational ages of the first two groups were 32 weeks with a high proportion of infants small-for-gestational-age. In group 1, FHR variation (mean range of pulse intervals) was less than half (20·6 SE 1·2 ms) of the normal value at the same age (44·4 SE 1·5 ms). This was associated with hypoxaemia (mean umbilical artery Po2 of 6 mmHg at delivery), with evidence of compensation shown by an elevated amniotic fluid erythropoietin. The fetuses were hypoglycaemic and had greater umbilical artery blood alanine concentrations, but no large changes in adenine nucleotide or endorphin plasma concentrations. Although there was a minor degree of respiratory acidaemia at birth, there was not significant metabolic acidaemia. The results demonstrate that the reduced variation of ‘suboptimal’ and ‘decelerative’ fetal heart rate records is associated with fetal hypoxaemia and evidence of nutritional deprivation, but not with asphyxia.

Notes: Summary. A microprocessor system is described for on-line analysis of the fetal heart rate detected by conventional Doppler systems. A brief account is given of the instrumentation and program structure. The system has been tested by analysing normal and abnormal antenatal fetal heart rate records. Pulse Doppler with autocorrelation measurement of the fetal pulse interval reduced the signal loss in clinical practice by a factor of 10, to an average of 2.1% in 629 records from uncomplicated pregnancies. Yet it is still necessary to identify signal loss, because it occasionally rises t o unacceptable levels in association with fetal movements or hiccups. Medium-term measures of fetal heart rate variation (within 16–0.1 cycles/min) varied with gestational age, but were a better index of fetal well-being than longer-term measures. The application of the system t o fetal monitoring is illustrated.

Notes: Objective:  In 1986, the British Society for Clinical Cytology (BSCC) published quantitative criteria to assist diagnosis in a three-tier grading system of squamous cell dyskaryosis. In dyskaryotic cells, area nuclear to cytoplasmic (NC) ratios below 50%, between 50% and 66% and over 66% were defined as equating with mild, moderate and severe grades respectively. Following the Terminology Conference in 2002, however, the BSCC recommended on their website that the three-tier model should be replaced by a new two-tier system of low- and high-grade squamous abnormalities. The latter broadly equate with the two-grade Bethesda System (TBS) for reporting squamous intraepithelial lesions. The purpose of this study was to assess the accuracy and reproducibility of the BSCC three-tier quantitative definitions, to investigate if they were applicable to liquid-based cytology (LBC) and to see how they related to the proposed new two-tier BSCC system.Methods:  Quantitative image analysis was undertaken on illustrations from the 1986 BSCC terminology publication and on microscope slides from external quality assessment and Cytology Training Centre teaching sets.Results:  Analysis of mean NC ratios showed that mild, moderate and severe dyskaryosis exist as statistically different populations. Overlap of NC ratio ranges, however, limits their practical application in the three-tier model, although interestingly no overlap was noted between mild and severe dyskaryosis. No grade of dyskaryosis had a mean area NC ratio over 50%, indicating that the BSCC quantitative definitions are incorrect. The mean diameter NC ratios for mild, moderate and severe dyskaryosis were found to be 40%, 49% and 66% respectively. Accordingly it is possible that those reporting cervical cytology could be interpreting the BSCC NC ratios as meaning diameter rather than area. Amalgamation of the three-tier results into the proposed two-tier model shows that the resulting mean NC area and diameter ratios identify statistically different low- and high-grade populations. The reduced degree of overlap, however, of NC ratio ranges in the two-tier model implies that NC ratios could have a useful practical role in the separation of the low- and high-grade categories. The two categories were reasonably well separated by mean area and diameter NC ratios of 25% and 50% respectively. A two-tier model combining mild with moderate rather than severe dyskaryosis was found to be a statistically valid alternative but gave rise to NC ratios that would be difficult to use in practice. Except for moderate dyskaryosis, no significant differences were identified between the mean NC ratios of either conventional and LBC preparations or LBC preparations using two different commercial methodologies (SurePathTM and ThinPrep®). Differences, however, were noted in area measurements between SurePathTM and ThinPrep® and this has potential implications for classifications (such as TBS) using area comparisons as their basis. In addition, it was found that the increased NC ratio, associated with higher grades of dyskaryosis is more a consequence of progressive cytoplasmic area reduction rather than nuclear area increase. The similar NC ratios of borderline nuclear changes associated with human papilloma virus and mild dyskaryosis support the BSCC proposal that these can be combined to constitute a low-grade category. This study shows that the BSCC area NC ratio criteria of grading squamous cell dyskaryosis require amendment. In addition, this study supports the new BSCC recommendation of low- and high-grade squamous cell categories.Conclusions:  The study proposes Sheffield quantitative criteria to assist the grading of squamous cell abnormalities. Quantitative diameter NC ratio measurements, however, must always be accompanied by detailed assessment of qualitative morphological features and in particular those relating to nuclear chromatin. This is equally relevant to both two- and three-tier models.

Notes: Objective:  This study assesses the accuracy of published quantitative and qualitative criteria in the Bethesda System (TBS) for squamous intra-epithelial lesions.Methods:  Quantitative image analysis was undertaken on illustrations from TBS publications and also from slides in Cytology Training Centre teaching sets. Comparisons were also made with the British Society for Clinical Cytology (BSCC) terminology in cervical cytology, using the illustrations in their terminology publication and amalgamating the results into their proposed new two-tier model.Results:  TBS quantitatively defines low-grade squamous intra-epithelial lesions (LSIL) in both conventional and liquid-based cytology (LBC) preparations as showing nuclear enlargement more than ×3 the area of a normal intermediate squamous cell nucleus. This study found that the increase in mean nuclear area was limited to only ×2 in conventional preparations. In LBC (SurePathTM) preparations, there was only a statistically non-significant ×1.2 increase. This study identified a progressive and statistically significant reduction in mean cytoplasmic area from normal intermediate cells to LSIL and then to high-grade squamous intra-epithelial lesions (HSIL) in both conventional and LBC preparations. Furthermore, the most consistent quantitative finding in both conventional and LBC preparations was a statistically significant increase in the mean area and diameter ratios from normal intermediate cells to LSIL and then to HSIL. In all instances this varied from ×2 to just below ×3. This is in agreement with TBS, which states that the cytoplasmic area in HSIL is decreased leading to a marked increase in nuclear to cytoplasmic (NC) ratio. With the exception of an increase in mean nuclear area in conventional preparations from normal intermediate cells to LSIL, the predominant cause for this increase in NC ratios was a reduction in mean cytoplasmic area. The numerical increase in NC ratio for LSIL identified in this study was greater than implied by the ‘slightly increased’ statement in TBS. TBS comments that some HSIL cells can have the same degree of nuclear enlargement as in LSIL and that other HSIL cells may have much smaller nuclei than in LSIL. Both of these qualitative comments were supported in this study. The mean diameter NC ratios of 33% and 50% could provide useful diagnostic assistance in the distinction of normal intermediate cells and LSIL and between LSIL and HSIL, respectively. Because of overlapping individual ranges, however, additional diagnostic features such as nuclear morphology must be used in the distinction of normal intermediate cells, LSIL and HSIL. No statistical difference was identified in the mean diameter NC ratios between ASC-US and LSIL in TBS publications. In addition, the proposed new BSCC low and high grades of squamous abnormality were not statistically different from ASC-US/LSIL and HSIL, respectively. This provides support that the proposed BSCC two-tier system of squamous abnormalities is comparable to TBS. This study shows that LBC has variable but major and significant effects on nuclear and cytoplasmic morphology and that quantitative definitions in conventional preparations cannot be automatically extrapolated to LBC methodology.Conclusions:  The study shows that some TBS quantitative and qualitative criteria require amendment and that an alternative quantitative approach, such as diameter NC ratio has a more valid scientific evidence base. Furthermore, use of NC ratios avoids the problems associated with the variable changes in nuclear and cytoplasmic areas, occurring between conventional and different commercial LBC preparations. By contrast, classifications based on area comparisons must be tailored to the specific conventional or commercial LBC preparation.

Notes: Summary Wheat straw treated with 0.5 or 1.0 ml/g urea-sulfuric acid (1:1 acid in water v/v) and incubated in Protneuf or Woodburn silt loam soils in the laboratory decomposed faster than nontreated straw the first 4–6 weeks but at 12 weeks the nontreated straw had decomposed 25%–45% more. In a field experiment, urea-sulfuric acid treated straw, removed at 40-day intervals over 160 days, decomposed faster than nontreated straw. The differences were attributed to salt buildup in the laboratory samples, where electrical conductivities up to 17.6 dS/m were observed. In the field, leaching removed the excess salts. Nitrification produced up to 1875 mg NO 3 − N/kg Portneuf silt loam soil in the laboratory, indicating that nitrifying bacteria were not suppressed by the salt. Total plate counts with no straw were 1.8 × 106 microorganisms/g and with urea-sulfuric acid treated straw were 15.7 × 106/g soil after 14 days incubation. The respective actinomycete counts were 0.3 × 106 and 6.7 × 106/g for the no straw and straw-treated soils, respectively. The urea-sulfuric acid treatments suppressed straw decomposition in the laboratory and accelerated straw decomposition in the field.