Heads you win, tails you lose: filtration processing for the microscopical examination of sperm heads.

The sperm head plays a key role in many fertilisation events and determining the precise location of molecules within the head region is important in mechanistically dissecting the fertilisation process. Such molecules may be present in low copy number and many sperm head profiles must be examined to localise them to particular subcellular structures with confidence. Filtration has traditionally been used for the purpose of concentrating biological material, such as free-living cells, spores, and subcellular fractions, and little attempt has been made to extend the procedure to encompass the entire processing schedule, mainly due to the incompatibility of intermediate dehydrating solvents with membrane filters. The novel and simple technique of filtration processing that we describe produced a dense mat of cells, with several sperm heads being visible in coronal orientation in a high-power field at the light microscopic level, and allowed positive immunocytochemical staining to be identified with confidence. This new technique exploits the low viscosity of LR White acrylic resin to allow the entire processing procedure to be undertaken in the filtration apparatus. In contrast, conventional techniques for preparing free-living cells, namely pre-embedding in a supportive matrix prior to processing, and centrifugation at each stage of the processing procedure, proved suboptimal, partly due to the final concentration that could be achieved, but mainly due to the random orientation of cells that these techniques afforded.

Biologically targeted probes for Zn2+: a diversity oriented modular "click-SNAr-click" approach†Electronic supplementary information (ESI) available: Full experimental details including characterisation of all novel compounds can be found in the ESI. See DOI: 10.1039/c4sc01249f.

We describe a one-pot strategy for the high yielding, operationally simple synthesis of fluorescent probes for Zn2+ that bear biological targeting groups and exemplify the utility of our method through the preparation of a small library of sensors. Investigation of the fluorescence behaviour of our library revealed that although all behaved as expected in MeCN, under biologically relevant conditions in HEPES buffer, a plasma membrane targeting sensor displayed a dramatic switch on response to excess Zn2+ as a result of aggregation phenomena. Excitingly, in cellulo studies in mouse pancreatic islets demonstrated that this readily available sensor was indeed localised to the exterior of the plasma membrane and clearly responded to the Zn2+ co-released when the pancreatic beta cells were stimulated to release insulin. Conversely, sensors that target intracellular compartments were unaffected. These results demonstrate that this sensor has the potential to allow the real time study of insulin release from living cells and exemplifies the utility of our simple synthetic approach.

Improving neonatal unit admission temperatures in preterm babies: exothermic mattresses, polythene bags or a traditional approach?

OBJECTIVE: To investigate whether exothermic sodium acetate mattresses were associated with an improvement in the thermal care of babies <30 weeks gestation between birth and admission to a neonatal unit. STUDY DESIGN: Analysis of a three case series of babies: the first with traditional thermal care of drying and wrapping in a towel, the second with wrapping in food standard polythene bags and the third with wrapping in polythene bags and nursing on an activated exothermic mattress. The main outcome measure was the temperature on admission to the neonatal unit. RESULT: There were no significant differences between the groups for gestation and birth weight. Hypothermia was less frequent in the 'bag and mattress' group compared with the 'bag only' and traditional care groups (26 vs 69 vs 84%, respectively) even though the median time to admission was longest in the 'bag and mattress' group (23 min). The proportions of babies admitted with temperatures in the target range of 36.5 to 37.5 degrees C were 46, 27 and 16%, respectively. Multiple regression analysis showed that use of the mattress raised admission temperatures by 1.04 degrees C. The median temperature of babies in the 'bag and mattress' group was higher compared with the other groups (36.9 vs 36.0 vs 35.8 degrees C), but significantly more were hyperthermic (28 vs 4 and 0.4%, respectively). CONCLUSION: Use of exothermic mattresses for babies <30 weeks gestation was associated with a significantly greater proportion of babies being admitted to the neonatal unit with a temperature in the euthermic range, but there was also an increased risk of hyperthermia.

Sucrose and non-nutritive sucking for the relief of pain in screening for retinopathy of prematurity: a randomised controlled trial.

BACKGROUND: Screening is necessary for infants at risk of retinopathy of prematurity. Despite local anaesthetic drops, infants find eye examinations distressing, displaying behavioural and physiological changes indicating acute pain. Oral sucrose and non-nutritive sucking reduce pain responses associated with invasive procedures. OBJECTIVE: To evaluate the use of oral sucrose and/or pacifier for reducing pain responses during eye examinations. METHODS: Forty infants <32 weeks gestation or <1500 g birth weight, in two neonatal units, were randomised to one of four interventions administered two minutes before their first screening examination: 1 ml sterile water as placebo (group 1, n = 10), 1 ml 33% sucrose solution (group 2, n = 10), 1 ml sterile water with pacifier (group 3, n = 9), or 1 ml 33% sucrose solution with pacifier (group 4, n = 11). Examinations were videotaped. Two observers, blind to the intervention, assessed recordings. Pain responses were scored using the premature infant pain profile (PIPP). RESULTS: The groups were similar in gestation, birth weight, and age at examination. Mean PIPP scores were 15.3, 14.3, 12.3, and 12.1 for groups 1, 2, 3, and 4 respectively. Analysis of variance showed a significant difference in PIPP score between groups (p = 0.023). Infants randomised to pacifiers scored lower than those without pacifiers (p = 0.003). There was no difference between groups receiving sucrose and those receiving water (p = 0.321). CONCLUSIONS: Non-nutritive sucking reduced distress responses in infants undergoing screening for retinopathy of prematurity. The difference in response was large enough to be detected by a validated assessment tool. No synergistic effect of sucrose and pacifier was apparent in this group.

Isolated mild fetal ventriculomegaly.

Ventriculomegaly is an excess of fluid in the lateral ventricles within the developing cerebrum. It is usually diagnosed at a routine fetal anomaly scan at 18-22 weeks gestation. Management of the condition and counselling of parents are difficult, as the cause, absolute risk, and degree of resulting handicap cannot be determined with confidence.

Hypertension in the newborn baby.

Hypertension is rare in the newborn infant. It has a cumbersome definition and diagnosis, and screening is not justified using present definitions and technology. Thresholds for starting antihypertensive treatment in the first month of life are not clear, and the treatment is difficult, with idiosyncratic responses to drugs in neonates with varying renal and hepatic function.

Events before the diagnosis of a pneumothorax in ventilated neonates.

AIM: To examine the relation of overventilation and other clinical events to the development of pneumothoraces in ventilated neonates. METHODS: A case-control study. RESULTS: Fifty three (8.7%) of 606 ventilated neonates developed a pneumothorax. Eighteen (34%) cases and 23 (43%) controls were unintentionally overventilated (PaCO(2) < 4 kPa) at some time before the pneumothorax developed in the cases (odds ratio (OR) = 0.78, 95% confidence interval (CI) 0.48 to 1.27). In the three hours before the diagnosis of pneumothorax, more cases than controls were reintubated (21/53 v 4/53; OR = 5.25, 95% CI 1.9 to 14.3), and also in seven cases (one control) the mean airway pressure was increased, whereas in nine controls (no cases) it was reduced (chi(2) = 12.0, df = 2, p = 0.001). Seven of 18 neonates diagnosed by transillumination had undergone no clinical procedures before diagnosis compared with five of 35 diagnosed radiologically (OR = 2.7, 95% CI 1.0 to 7.4). CONCLUSIONS: Unintentional overventilation was not associated with pneumothoraces. In the hours before diagnosis, there was increased clinical intervention, including reintubation; this was less so in those diagnosed by transillumination. The study did not elucidate whether such interventions caused the pneumothorax or were secondary to a failure to diagnose it.

Ophthalmic Pseudomonas infection in infancy.

Four infants developed invasive Pseudomonas aeruginosa ophthalmic infections between 5 and 90 days of age. Three died from septicaemia, and the fourth required enucleation of one eye. Absent red reflexes or other eye signs in a septicaemic infant merit urgent ophthalmological assessment for endophthalmitis, in particular, Pseudomonas.

Classifying perinatal death: experience from a regional survey.

OBJECTIVE: To examine problems encountered in classifying perinatal death using the systems proposed by Hey et al. (1986) and Cole et al. (1986). SUBJECTS: 451 deaths from a regional perinatal mortality survey of which 293 had a post mortem examination. METHODS: Documents from each death were reviewed by four assessors, one from each discipline, selected randomly from a pool of obstetricians, paediatricians, general practitioners and midwives. Each assessor classified the cause of death blind to the others. The degree of agreement between assessors was calculated for the full and shortened obstetric and fetal-neonatal classifications using the kappa statistic for inter-rater agreement. RESULTS: The kappa statistic, which is a measure of the proportion of agreement above chance, gave a value of 0.55 for the full obstetric classification and 0.58 for the full fetal and neonatal classification when all four assessors made an assignment. An assignment was omitted in 6.2%, but the kappa value of zero for these omissions suggested that this was a nonsystematic result due to random protocol violations. The grouped (shortened) classifications generated a higher kappa value of 0.62 for the nine point obstetric system and 0.67 for the six point fetal and neonatal (New Wigglesworth) system. Post mortem had little effect on agreement. The best agreement levels observed were for congenital anomaly. CONCLUSION: This survey highlighted the complexity of the 22 and 24 point classifications, the uneven distribution of deaths within their categories, and the variable levels of agreement between professionals classifying deaths, thus questioning the validity of individual maternity units of health districts generating local data in this degree of detail for comparative purposes in regional and national statistics. Grouping the original categories led to greater agreement particularly for the New Wigglesworth classification. The role of post mortems in clarifying the cause of fetal and neonatal death needs further investigation.

Staphylococcus aureus still colonizes the untreated neonatal umbilicus.

Two different neonatal umbilical cord treatment regimens were studied prospectively. Although a greater proportion of cords had separated by the seventh day in those babies not treated with topical antiseptics (47% vs. 26%), there was a significant excess (53% vs. 30%) of umbilical colonization by Staphylococcus aureus compared to those neonates whose cords were treated with alcohol wipes and hexachlorophane powder. The main purpose of treating cords is to prevent significant S. aureus colonization, and therefore current proposals to stop antiseptic treatment of umbilical cords should be disregarded.

Babies born before arrival at hospital.

OBJECTIVE: To establish the prevalence of babies born before arrival at two local hospitals. To identify women at risk of giving birth before arrival, and the morbidity and mortality associated with such births. DESIGN: A case control study. Each baby born before arrival and its mother were compared with the next born in the hospital (random control), and one matched for gestation and birthweight, together with their mothers. SETTING: Two maternity units serving East Birmingham and Solihull. SUBJECTS: All babies (and their mothers) born before arrival at these hospitals from January 1983 to December 1987. MAIN OUTCOME MEASURES: Perinatal mortality rates, patterns of perinatal morbidity, demographic, social and obstetric features of the mothers. RESULTS: 137 (0.44%) of 31,140 consecutive births were before arrival at hospital (BBA group). The perinatal mortality rate in the BBA group was 58.4/1000 (8 deaths) compared with 10.1/1000 for all inborn babies (relative risk 5.8, 95% confidence interval 2.9-11.4). In the BBA group the mean birthweight of 3008 g was 212 g (95% CI 50-374 g) less than that in the random control group; the mean gestation of 266 days was 10 days less (95% CI 5.9-14.1 days) than in the random control group. Hypothermia was the commonest morbidity. Women delivered before arrival tended to be either multigravid inner city Asians living a long way from the hospital or unmarried unbooked younger white Europeans. CONCLUSIONS: The high perinatal mortality was related to immaturity and low birthweight, rather than to birth before arrival itself. Although groups of mothers at risk of delivery before arrival can be identified more information is needed to establish whether additional antenatal care would be beneficial for these women and their babies.