Relationship between maternal growth, infant birthweight and nutrient partitioning in teenage pregnancies.

OBJECTIVE: Teenagers are susceptible to delivering small-for-gestational-age (SGA) infants. Previous studies suggest that maternal growth may contribute, as a result of preferential nutrient partitioning to the mother. We investigated the impact of maternal growth on birthweight in pregnant teenagers in the UK, and examined endocrine mediators of nutrient partitioning. DESIGN: A prospective observational multicentre study, About Teenage Eating, conducted between 2004 and 2007. SETTING: Four hospitals in socially-deprived areas of Manchester and London. POPULATION: A total of 500 pregnant adolescents (14-18 years of age) with a singleton pregnancy were recruited at 10-21 weeks of gestation, with follow-up studies on 368 subjects. A cohort of 80 pregnant adults (25-40 years of age) provided a control group for determining growth. METHODS: Skeletal growth, weight gain and skinfold thickness were measured from first to third trimester, together with maternal levels of micronutrients and metabolic hormones: insulin-like growth factor (IGF) system and leptin. Dietary analyses were performed. MAIN OUTCOME MEASURE: SGA birth. RESULTS: Maternal growth was not associated with SGA birth: growing mothers delivered more large-for-gestational-age infants (OR 2.51; P < 0.05). Growers had greater weight gain (P < 0.001), fat accrual (P < 0.001) and red cell folate concentrations (P < 0.01) than non-growers. Maternal IGF-I (P < 0.01) and leptin (P < 0.001) were positively associated with maternal and fetal growth, whereas IGF-I (P < 0.001) was negatively associated. Teenagers that were underweight at booking or with low weight gain were at greater risk of SGA birth. CONCLUSIONS: Maternal growth was not detrimental to fetal growth in this UK population of teenagers. Greater weight gain and higher concentrations of IGF-I in growing teenagers may provide anabolic drive for maternal and fetal growth.

Age-related changes in the fibre composition of equine peripheral nerve.

Transverse sections of the lateral palmar nerve from a group of horses free from neuromuscular disease were assessed quantitatively, with emphasis on differences in the fibre population related to age. Morphometric analysis of the population of myelinated and unmyelinated fibres was performed. Changes were identified, there being a loss of larger myelinated fibres in older horses. The relationship of myelin thickness to axon diameter and the unmyelinated fibre population did not alter with age. The lateral palmar nerve is suitable for biopsy and electrophysiological study in the horse, but age related changes must be appreciated in the interpretation of results.

Effect of age on sensory nerve conduction velocity in the horse.

This study aimed to establish a clinically reproducible method of evaluation of sensory nerve conduction in the horse and to provide reference values in a group of normal horses. Age-related changes in the sensory nerve conduction velocity were of particular interest. Sensory nerve conduction was performed in the lateral palmar nerve. The results revealed an increase in velocity over the first year of life and a subsequent decrease in velocity in older horses. The effect of age must be considered if results from horses in which peripheral nerve disease is suspected are to be interpreted correctly. The results reflect similar findings in man and other domestic species.

Quantitative and qualitative morphology of equine peripheral nerve: teased fibre studies.

Single teased fibre studies were made on samples of the lateral palmar nerve from 16 horses of mixed age and size which had no evidence of neuromuscular disease. Significant proportions of abnormal fibres indicative of axonal degeneration/regeneration and demyelination/remyelination were identified. Measurements of internodal length and fibre diameter were made. Internodal length was shown to be related to fibre diameter, changes in this relationship being mainly influenced by the incidence of abnormal fibres rather than by the age of the horse. Information about the incidence of abnormal fibres in normal horses is required if findings in biopsy material are to be interpreted correctly.

Vertebral plasma cell tumors in 8 dogs.

The case histories of 8 dogs with spinal pain and neurologic deficits associated with vertebral plasma cell tumor are reviewed. Four dogs had solitary plasmacytoma, 3 had multiple myeloma, and 1 dog had 2 vertebral lesions with no evidence of disseminated disease. Four dogs were treated: 2 with multiple myeloma received chemotherapy only and survived 17 and 26 months, respectively. Two dogs with solitary plasmacytomas of the spine had chemotherapy and radiotherapy: the 1st survived 4 months and was euthanized after developing radiation myelopathy; the 2nd survived 65 months before developing multiple myeloma. The diagnosis of solitary plasmacytoma of the spine versus multiple myeloma is discussed.

Influence of limb temperature on sensory nerve conduction velocity in horses.

Sensory nerve conduction velocity was measured in the lateral palmar nerve of 8 horses. The limb temperature was manipulated by external means and monitored. Alterations in the nerve conduction velocity related to limb temperature variation were identified at both increased and decreased temperatures. These were quantified and a mean value of 2.15 +/- 0.2 m/s/degree Celsius was determined. The effect of altered limb temperature should be considered in nerve conduction velocity determinations.

Maturational changes in F waves in growing chickens.

The F waves evoked by supramaximal stimulation of distal tibial nerve were evaluated in chickens aged 2 to 15 weeks. Latency of these potentials increased from mean +/- SD 11.4 +/- 0.12 ms at week 2 to mean 12.88 +/- 0.65 ms at week 15. The F-wave latency increased linearly with age. When this latency was corrected for a standard distance to compensate for the increasing limb length with age, latency decreased with maturity.

Age-related effects on motor nerve conduction velocity in chickens.

Compound motor-nerve action potentials evoked by supramaximal stimulation of the proximal and distal aspects of the tibial nerve were evaluated in chickens 1 to 15 weeks old. Motor-nerve conduction velocity increased from a mean of 22.6 m/s at week 1 to a mean of 52.7 m/s at week 15. The increase in conduction velocity was greatest for the first few weeks, and reached a plateau at 10 weeks. Subcutaneous limb temperature, limb length, and proximal latency measurements also increased with age; however, distal latency measurements were not significantly influenced by age. A quadratic equation was calculated to predict mean motor-nerve conduction velocity for maturing chickens.

Effects of age on temperature-related variation in motor nerve conduction velocity in healthy chickens.

Muscle potentials evoked by stimulation of the sciatic nerve were evaluated in 4- and 15-week-old chickens. Each bird was anesthetized and slowly cooled externally from a normal body temperature of 40 C to 28 C, and motor nerve conduction velocities were measured at various intervals during cooling. Motor nerve conduction velocity decreased linearly with decreasing limb temperature in both groups. The rate of change in motor nerve conduction velocity per degree in 2 groups (2.13 m/s/C vs 1.84 m/s/C) fell just short of a statistically significant difference (P = 0.0508), indicating that an age-related effect on temperature-associated variation in motor nerve conduction velocity may be present.

Methods of clinical electrophysiologic study in pigs.

Methods of estimating motor nerve conduction, sensory nerve conduction, and f-wave latency in pigs were determined. The sciatic-tibial nerves were used for motor nerve conduction and f-wave response and the superficial peroneal nerve was used for sensory nerve conduction.

Episodic weakness associated with exertional lactic acidosis and myopathy in Old English sheepdog littermates.

Two Old English Sheepdog littermates were evaluated for weakness that developed during periods of minimally intense exercise. Lactic acidosis accompanied by increased muscle enzyme activity, an increased lactate/pyruvate ratio, and increased venous PO2 supported the possibility of defective mitochondrial oxygen use. Electromyographic abnormalities included increased insertional activity and complex repetitive discharges. Muscle alterations included scattered myofiber necrosis, abundant endomysial connective tissue, excessive glycogen accumulation, and greater than normal numbers and vacuolation of mitochondria. A distinctive pattern of subsarcolemmal mitochondrial aggregates, referred to as "ragged red fibers" in human mitochondrial myopathies, was observed in muscle biopsy samples from 1 dog. Several features of the disease in these dogs, including onset of weakness during early life, simultaneous disease in littermates, subtle nonprogressive weakness of at least 3 years' duration, and partial reversibility of lactic acidosis following rest were suggestive of an inborn error of metabolism, consistent with mitochondrial myopathy.

Lumbosacral disease.

Careful clinical and neurologic evaluations are the foundation on which a diagnosis of lumbosacral disease is based. Appropriate use of ancillary diagnostic aids will confirm the diagnosis and allow appropriate treatment to be instituted.

Neospora caninum infection in three dogs.

Infection with Neospora caninum in three young dogs is described. The predominant clinical signs were lower motor neuron deficits of the pelvic limbs, bladder and rectum. In two cases there was liver infection and dysfunction. The younger dogs had an acute onset rapidly progressive syndrome. The older dog had a similar but more chronic course. The diagnosis was confirmed by an immunofluorescence antibody test. The parasite is sensitive to clindamycin and trimethoprim/sulphonamide preparations, however the prognosis for return to function is poor especially if muscle contracture has occurred.

Treatment of acquired myasthenia gravis associated with thymoma in two dogs.

Two cases of myasthenia gravis associated with thymoma are reported. Both were female German shepherd dogs and the thymoma was surgically resected. Aspiration pneumonia secondary to persistent megaoesophagus was a complication in both cases. The myasthenia gravis did not resolve, but there was a more satisfactory control of clinical signs with anticholinesterase treatment. Corticosteroid therapy was used in one case, but the resulting polydipsia increased the incidence of regurgitation, resulting in recurrent episodes of aspiration pneumonia.

Comparison of two surgical techniques for the management of cervical spondylomyelopathy in dobermanns.

A study was undertaken to compare the efficacy of two surgical techniques for the treatment of caudal cervical spondylomyelopathy (CCSM): ventral decompression (slot) and vertebral distraction and stabilisation with a screw and washer (screw/washer). Twenty-eight dobermanns managed surgically for disc-associated CCSM during a four-year period were studied retrospectively. The maximum postoperative period was 40 months. Cases were excluded if a minimum follow-up of 24 months after surgery could not be made. A 'slot' took a longer time to perform and had a higher rate of immediate postoperative deterioration. Duration of hospital stay was similar for both procedures. At six months after surgery the two techniques were comparable; 12/14 (screw/washer) and 13/14 (slot) patients were deemed to have a satisfactory outcome. Recurrence of cervical spinal cord disease was higher in the screw/washer dogs. At one year after surgery the recurrence rate was zero (slot) and 5/14 (screw/washer), respectively. At two years after surgery 4/14 of the slot dogs had deteriorated compared to 7/14 of the screw/washer dogs. Where investigated, the cause of deterioration was either a domino disc lesion or vertebral endplate collapse and dorsal displacement of the screw and washer.

Factors influencing doctors' ability to calculate drug doses correctly.

Doctors and medical students are more likely to make errors in drug dose calculations when the strengths of drug solutions are expressed as ratios or percentages. We have already described how a doctor's specialty influences their drug dose calculation skills, having surveyed almost 3000 doctors in an online survey. Better teaching of drug administration skills or reinforcement of existing skills would appear to be needed. We sought to identify doctors that might benefit particularly from such teaching by other means than specialty alone, by subjecting existing data to further analysis. Almost 3000 doctors subscribing to a UK-based internet content provider had participated in an online questionnaire concerning drug-dose calculation. Each doctor's score in the multiple choice questionnaire was cross referenced with demographic data obtained from the hosts of the original survey whilst maintaining anonymity. Newly and recently qualified doctors, and doctors working in the community, struggled most with the calculations (p < 0.0001). There were also highly significant differences in the performances of doctors from different medical schools (p < 0.0001). As a new training programme for junior doctors is being introduced in the UK; we recommend that drug administration skills are given a prominent place in the curriculum, and again call for the standardisation of ampoule labelling to mass concentration.

Medication errors in anaesthesia and critical care.

There is an increasing recognition that medication errors are causing a substantial global public health problem, as many result in harm to patients and increased costs to health providers. However, study of medication error is hampered by difficulty with definitions, research methods and study populations. Few doctors are as involved in the process of prescribing, selecting, preparing and giving drugs as anaesthetists, whether their practice is based in the operating theatre, critical care or pain management. Anaesthesia is now safe and routine, yet anaesthetists are not immune from making medication errors and the consequences of their mistakes may be more serious than those of doctors in other specialties. Steps are being taken to determine the extent of the problem of medication error in anaesthesia. New technology, theories of human error and lessons learnt from the nuclear, petrochemical and aviation industries are being used to tackle the problem.

A view of the phenomenon of caring in nursing practice.

Care is regularly used as a suffix to nursing, in such well-known phrases as 'total nursing care' and 'holistic nursing care'. While most care is provided by lay persons, there is little nursing research which focuses on the meaning of care, particularly in relation to the United Kingdom. This small-scale study investigates the meaning of care from the experience of six practising staff nurses in a British hospital and leads to a view of this phenomenon. Phenomenology was the chosen methodology, which facilitated the emergence of an essential structure of caring which incorporated four major categories described as 'being supportive', 'communicating', 'pressure' and 'caring ability'. It is suggested that, through gaining perspectives to enhance our understanding of the meaning of care, it will ultimately develop our understanding of nursing itself.