Children on long-term ventilatory support: 10 years of progress

OBJECTIVES

To identify the number and current location of all children receiving long-term ventilation (LTV) in the UK, and to establish their underlying diagnoses and ventilatory requirements.

DESIGN

Single time-point census completed by members of the UK LTV working party using an electronic-based questionnaire

SUBJECTS

All children in the UK at home or in hospital who, when medically stable, continue to need a mechanical aid for breathing following a failure to wean beyond a 3-month period.

RESULTS

933 children under the age of 17 years in 30 regional centres were identified as receiving LTV. 88 children (9.5%) required continuous positive pressure ventilation by tracheostomy over 24 h, while 658 received ventilation while asleep only. Most children are ventilated by a non-invasive mask (n=704; 75%) or tracheostomy (n=206; 22%). Underlying conditions included neuromuscular disease (n=402; 43%), chronic respiratory (n=343; 37%) and central nervous system conditions (n=168; 18%). 129 (14%) children were aged 16 or over. 844 (91%) children were cared for at home with only 49 children listed as being in acute hospital units (n=34) or paediatric intensive care units/high dependency units (n=15).

CONCLUSIONS

The last 10 years has seen a very significant increase in the number of children requiring LTV in the UK with an increasing number cared for at home. This reflects both improving technology and increasing clinical expertise in paediatric non-invasive ventilatory support, and a continuing change in attitude towards long-term support, particularly in children with neuromuscular diseases. There are a substantial number of children who soon will require transition to adult services, yet few such services currently exist.

Effect of high versus low initial doses of L-thyroxine for congenital hypothyroidism on thyroid function and somatic growth

BACKGROUND AND AIMS

The optimal dose of thyroxine (T4) in congenital hypothyroidism (CH) during infancy is controversial. Higher doses lead to improvement in cognitive scores, but have been linked to later behavioural difficulties. We have examined the effects of initial T4 dosage on somatic growth--a putative surrogate marker of overtreatment.

METHODS

314 CH children (214 girls, 100 boys) were analysed according to initial daily dose of T4: Group 1 (25 mug, n = 152), Group 2 (30-40 mug, n = 63) and Group 3 (50 mug, n = 99). Thyroid function and weight, length and occipito-frontal head circumference (OFC) standard deviation score (SDS) were compared at 3, 6, 12, 18, 24 and 36 months of age. Linear growth SDS was compared between the three groups using a regression adjustment model at 12 and 18 months of age using birth weight and 3-month data as baselines. Thyroid function was also compared at diagnosis (T 0), and 7-21 days after the start of treatment (T1).

RESULTS

At T1 median thyroid stimulating hormone (TSH) for Groups 1, 2 and 3 was 58, 29 and 4.1 mU/l, respectively (p<0.001), Group 3 values remaining significantly lower at 3 and 6 months. Median free T4 (fT4) was within or just above the reference range in all groups at T1, but 7.4% of Group 1 had values <9 pmol/l compared with 5.1% and 0% for Groups 2 and 3, respectively. At 3 months weight, length and OFC SDS values were -0.39, -0.35, 0.09; -0.30, -0.47, 0.32; and -0.03, -0.13, 0.18 for Groups 1, 2 and 3, respectively, indicating relatively large OFC in all infants. A regression adjustment model showed no significant difference in growth rate from baseline and 12 or 18 months of age, between the three groups.

CONCLUSION

An initial T4 dose of 50 mug daily, normalises thyroid function several months earlier than lower-dose regimes, with no evidence of sustained somatic overgrowth between 3 months and 3 years.

Effect of high versus low initial doses of L-thyroxine for congenital hypothyroidism on thyroid function and somatic growth

BACKGROUND AND AIMS

The optimal dose of thyroxine (T4) in congenital hypothyroidism (CH) during infancy is controversial. Higher doses lead to improvement in cognitive scores, but have been linked to later behavioural difficulties. We have examined the effects of initial T4 dosage on somatic growth--a putative surrogate marker of overtreatment.

METHODS

314 CH children (214 girls, 100 boys) were analysed according to initial daily dose of T4: Group 1 (25 mug, n = 152), Group 2 (30-40 mug, n = 63) and Group 3 (50 mug, n = 99). Thyroid function and weight, length and occipito-frontal head circumference (OFC) standard deviation score (SDS) were compared at 3, 6, 12, 18, 24 and 36 months of age. Linear growth SDS was compared between the three groups using a regression adjustment model at 12 and 18 months of age using birth weight and 3-month data as baselines. Thyroid function was also compared at diagnosis (T 0), and 7-21 days after the start of treatment (T1).

RESULTS

At T1 median thyroid stimulating hormone (TSH) for Groups 1, 2 and 3 was 58, 29 and 4.1 mU/l, respectively (p<0.001), Group 3 values remaining significantly lower at 3 and 6 months. Median free T4 (fT4) was within or just above the reference range in all groups at T1, but 7.4% of Group 1 had values <9 pmol/l compared with 5.1% and 0% for Groups 2 and 3, respectively. At 3 months weight, length and OFC SDS values were -0.39, -0.35, 0.09; -0.30, -0.47, 0.32; and -0.03, -0.13, 0.18 for Groups 1, 2 and 3, respectively, indicating relatively large OFC in all infants. A regression adjustment model showed no significant difference in growth rate from baseline and 12 or 18 months of age, between the three groups.

CONCLUSION

An initial T4 dose of 50 mug daily, normalises thyroid function several months earlier than lower-dose regimes, with no evidence of sustained somatic overgrowth between 3 months and 3 years.

Adrenal responses to low dose synthetic ACTH (Synacthen) in children receiving high dose inhaled fluticasone

BACKGROUND AND AIMS

Clinical adrenal insufficiency has been reported with doses of inhaled fluticasone proprionate (FP) > 400 microg/day, the maximum dose licensed for use in children with asthma. Following two cases of serious adrenal insufficiency (one fatal) attributed to FP, adrenal function was evaluated in children receiving FP outwith the licensed dose.

METHODS

Children recorded as prescribed FP > or = 500 microg/day were invited to attend for assessment. Adrenal function was measured using the low dose Synacthen test (500 ng/1.73 m2 intravenously) and was categorised as: biochemically normal (peak cortisol response > 500 nmol/l); impaired (peak cortisol < or = 500 nmol/l); or flat (peak cortisol < or = 500 nmol/l with increment of < 200 nmol/l and basal morning cortisol < 200 nmol/l).

RESULTS

A total of 422 children had been receiving FP alone or in combination with salmeterol; 202 were not investigated (137 FP within license; 24 FP discontinued); 220 attended and 217 (age 2.6-19.3 years) were successfully tested. Of 194 receiving FP > or = 500 microg/day, six had flat responses, 82 impaired responses, 104 were normal, and in 2 the LDST was unsuccessful. Apart from the index child, the other five with flat responses were asymptomatic; a further child with impairment (peak cortisol 296 nmol/l) had encephalopathic symptoms with borderline hypoglycaemia during an intercurrent illness. The six with flat responses and the symptomatic child were all receiving FP doses of > or = 1000 microg/day.

CONCLUSION

Overall, flat adrenal responses in association with FP occurred in 2.8% of children tested, all receiving > or = 1000 microg/day, while impaired responses were seen in 39.6%. Children on above licence FP doses should have adrenal function monitoring as well as a written plan for emergency steroid replacement.

Improvement in screening performance and diagnosis of congenital hypothyroidism in Scotland 1979-2003

AIM

To assess the Scottish newborn screening programme for congenital hypothyroidism from 1994 to 2003 (period 2) for performance and compare with an initial audit covering 1979 to 1993 (period 1).

DESIGN

Performance data-age at blood spot sampling, notification by screening laboratory, start of treatment, and the prevalence of late testing, notification or treatment-were compared, together with the incidence of congenital hypothyroidism.

RESULTS

Comparing data for period 2 with period 1, the mean annual incidence of true congenital hypothyroidism was 1:3655 live births v 1:4363. Median age for Guthrie sampling (all referrals) was 6 v 7 days (p<0.0001). Late sampling (>10 days) had fallen from 10.7% to 7%. For infants requiring repeat sampling before notification, the median (range) interval between initial and final repeat samples was 11 (1 to 52) compared with 14 (3 to 73) days. Median age at notification for true congenital hypothyroidism was 10 v 12 days (p <0.0001). Late notification (>15 days) was justifiable (mild TSH elevation) in 10 of 13 patients in period 2. Median age at start of treatment for true congenital hypothyroidism had improved to 11 days from 13.5 days. For true congenital hypothyroidism, late treatment (>16 days) occurred in 7% of patients compared with 19% (p<0.0001).

CONCLUSIONS

There has been an improvement in performance measures for the congenital hypothyroidism screening programme in Scotland. However, late sampling, occurring primarily in inpatients and which is never justified, remains a problem, while the interval between initial and recall sampling is a further source of delay.

Contraceptive responses of mice immunized with purified recombinant mouse zona pellucida subunit 3 (mZP3) proteins

Mouse zona pellucida subunit 3 (mZP3) was tested for efficacy as an immunocontraceptive antigen by comparing the fertility of mice immunized with recombinant mZP3 proteins. Recombinant protein was expressed using either the vaccinia virus T7 mammalian (vmZP3 protein) or baculovirus insect cell (bmZP3 protein)-expression systems. Female BALB/c or wild mice were immunized by i.p. injection using Freund's complete adjuvant and boosted three times with affinity purified recombinant proteins in Freund's incomplete adjuvant. Most mice developed antibodies that crossreacted to the respective mZP3 antigens by ELISA or western blot. In BALB/c mice immunized with vmZP3, fertility and mean litter size were reduced transiently to 25% and 10%, respectively, of those of control mice. However, immunization with bmZP3 did not affect either the fertility or mean litter sizes in BALB/c or wild mice immunized with bmZP3. The results demonstrate that reduction in fertility can be achieved in female BALB/c mice immunized using Freund's adjuvants and recombinant mZP3 protein produced in a mammalian, but not an insect, cell-expression system. Arguments are presented for the likely role of glycosylation of the mZP3 antigen in inducing contraceptive immune responses.

Expression of mouse interleukin-4 by a recombinant ectromelia virus suppresses cytolytic lymphocyte responses and overcomes genetic resistance to mousepox

Genetic resistance to clinical mousepox (ectromelia virus) varies among inbred laboratory mice and is characterized by an effective natural killer (NK) response and the early onset of a strong CD8(+) cytotoxic T-lymphocyte (CTL) response in resistant mice. We have investigated the influence of virus-expressed mouse interleukin-4 (IL-4) on the cell-mediated response during infection. It was observed that expression of IL-4 by a thymidine kinase-positive ectromelia virus suppressed cytolytic responses of NK and CTL and the expression of gamma interferon by the latter. Genetically resistant mice infected with the IL-4-expressing virus developed symptoms of acute mousepox accompanied by high mortality, similar to the disease seen when genetically sensitive mice are infected with the virulent Moscow strain. Strikingly, infection of recently immunized genetically resistant mice with the virus expressing IL-4 also resulted in significant mortality due to fulminant mousepox. These data therefore suggest that virus-encoded IL-4 not only suppresses primary antiviral cell-mediated immune responses but also can inhibit the expression of immune memory responses.

Sporadic acute hepatitis E in the united kingdom: an underdiagnosed phenomenon?

BACKGROUND

Hepatitis E (HEV) is the primary cause of enterically transmitted non-A non-B hepatitis worldwide. Case reports of HEV in individuals in the United Kingdom relate to travel to endemic areas or contact with individuals who have visited these areas.

CASE REPORTS

Four individuals presented with acute hepatitis to a hepatology clinic in a teaching hospital. Serology confirmed acute hepatitis E in all four. Investigation by the Communicable Disease Control Department established no links between the cases, no travel to an endemic area, and no contacts.

CONCLUSION

Contrary to current belief, community acquired hepatitis E virus infection occurs sporadically in the United Kingdom and should be considered as a cause of seronegative hepatitis.

Cloning and characterization of the cDNA encoding the PH20 protein in the European red fox Vulpes vulpes

The PH20 protein is thought to play a crucial role in mammalian fertilization. The fox PH20 homologue has been cloned from a testis cDNA library and the deduced protein sequence shows high levels of homology to PH20 proteins isolated from other species. Unlike other PH20 proteins the fox protein does not appear to be membrane associated through a GPI-linkage nor does it show the presence of a transmembrane domain at the C-terminus of the protein. It is in this region that the proteins appear to be least conserved. Immunolocalization studies on fox sperm show that the PH20 protein is located on the inner acrosomal membrane. Transcription of PH20 in the fox is seasonally regulated, with the mRNA expressed during those months when spermatogenesis is at its peak. The PH20 sequence described in this paper has been submitted to the Genbank database and has the accession number U41412.

Community outbreak of psittacosis in a rural Australian town

BACKGROUND

Health authorities in Victoria, Australia were notified of three men from a rural town with atypical pneumonia, admitted to hospital over 8 days. Initial serological testing suggested Chlamydia psittaci as the cause. We did a case-control study to find risk factors for psittacosis.

METHODS

We searched for cases of pneumonia or severe flu-like illness through family physicians and the regional hospital. We selected three controls per case from the region's electoral roll. We collected blood for serological tests and administered questionnaires to all cases and controls.

FINDINGS

We found 16 cases of psittacosis and one died. Most cases were clustered within a small geographical area, with a median age of 58 years (range 23-76), 15 (94%) of whom were male. Keeping, handling, or feeding domestic or wild birds was not associated with illness. Cases spent a median of 17.5 h per week in their garden, compared with a median of 5.2 h for controls (p=0.04) and were more likely to have mowed lawns during the 3 weeks before onset of illness than controls (odds ratio 4.81 [95% CI 1.08-33.37]).

INTERPRETATION

We showed that psittacosis outbreaks are not limited to direct contact with birds and pose new challenges for disease control. Modifications may be needed to work outdoors to decrease the risk of psittacosis.

Generic nursing outcome objectives for use in long-term care facilities

Twenty-two registered nurses employed in four long-term care facilities generated data for a study about nursing diagnoses in long-term care (N = 360). Generic outcome objectives were developed as an integral part of the project. The research team also specified exceptions to the outcomes: instances where meeting outcome objectives might not be possible. The outcome objectives and exceptions for the sample's 20 most frequently occurring nursing diagnoses are presented as working statements. The authors expect that these outcome objectives and exceptions will be revised by nurses who use them in practice, basic and continuing education, and research.

A case of human anthrax in Victoria

A human case of anthrax was identified through surveillance of knackery workers who had been exposed to infected cattle. The outbreak in cattle has affected 38 herds in the Stanhope/Tatura area of central northern Victoria. The human case, a 39 year old male, was treated in hospital and is recovering. Surveillance of other knackery workers has now been completed, and no other cases were found. Public health measures are in place to prevent further human cases.

Alterations in erythrocyte band 3 organization induced by the photosensitizer, hematoporphyrin derivative

Photosensitization of erythrocytes in the presence of hematoporphyrin derivative causes cross-linking of membrane proteins. This cross-linking is associated with partial lysis of the cells and an increased susceptibility to heat-induced membrane fragmentation. The effect of photosensitization on the organization of erythrocyte band 3 was monitored using the technique of time-resolved phosphorescence anisotropy. Band 3 rotational diffusion was somewhat restricted upon photooxidation, indicating aggregation of this major integral membrane protein.

The MicroScan WalkAway diagnostic microbiology system--an evaluation

The MicroScan WalkAway is an automated bacterial identification and susceptibility testing system that has only recently been marketed in Australasia. We evaluated the performance of the instrument using MicroScan Rapid fluorescent panels to determine the identity and antibiotic susceptibilities of 100 Gram negative and 100 Gram positive organisms representing both common clinical isolates and selected organisms of interest. MicroScan results were compared with those obtained by conventional biochemical identification, and antibiotic susceptibility testing using agar dilution following the National Committee on Clinical Laboratory Standards guidelines. MicroScan and reference identifications were in agreement for 93% of Gram negative organisms. MicroScan results were available within 2 hrs. Additional tests were required to confirm the identity of 9 isolates but on only 2 occasions would a definitive identification been delayed beyond 24 hrs. Very major or major discrepancies were seen in 2% and minor discrepancies in 8% of Gram negative susceptibility tests. Susceptibility results were available within 7 hrs but could not be obtained for 13 slow growing organisms. With Gram positive organisms MicroScan agreed with the reference identification of 87% of isolates cultured on horse and 90% of those cultured on sheep blood agar. Discrepancies that occurred in the identification of some streptococci made us question the suitability of MicroScan as the sole means of identifying these organisms. All identifications were available within 24 hrs and the requirement for additional tests was minimal. Susceptibility results closely matched those obtained by agar dilution with < 1% major and 7% and 9% minor discrepancies occurring with sheep and horse blood respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Cloning and partial characterization of the cDNA encoding the fox sperm protein FSA-Acr.1 with similarities to the SP-10 antigen

We have isolated and characterized a cDNA, cFSA-Acr.1, encoding a testis-specific fox sperm antigen. The antigen is located on the inner acrosomal compartment, and is expressed during spermatogenesis on the developing acrosome of round and elongating spermatids. Database searches with the deduced amino acid sequence of cFSA-Acr.1 revealed that the clone has high homology to both human and baboon sperm protein SP-10, and the mouse sperm protein, MSA-63. The region of highest homology is within the carboxyl terminus. In the middle of the open reading frame, the fox sequence shows unique sequences absent from both the human, baboon SP-10, and mouse MSA-63 sequences. In addition to cFSA-Acr.1, two other clones were also isolated from the same fox testis cDNA library, and sequence analysis shows that they may represent alternatively spliced mRNAs coding for other FSA-Acr proteins.

Exploratory research as andragogic continuing education

The continuing education aspect of an exploratory research project was evaluated in terms of Knowles's learning assumptions and teaching design factors. Although most of the project's assumptions were congruent with Knowles's andragogic assumptions, the design factors were found to be more pedagogic. Using more andragogic design factors in the future would strengthen this continuing education approach.

Cloning and characterization of a fox sperm protein FSA-1

A monoclonal antibody was raised to a fox sperm protein (FSA-1) which was found to be localized to the inner acrosomal compartment of sperm fixed in methanol. Western blots of testicular germ cell membrane extracts probed with this antibody identified a major protein band with a molecular weight of 36,000. Immunofluorescent studies on fox testis sections showed that the antigen is expressed on round and elongating spermatids on a crescent-shaped structure, which probably represents the developing acrosome. An antibody specific for FSA-1 was used to screen a fox testis cDNA library for its cognate gene. An 875-bp cDNA clone was isolated and sequenced revealing an open reading frame. Searches of the GenBank and EMBL databases with the nucleic acid sequence revealed significant homology (86%) of FSA-1 with 406 bases of an unidentified RNA transcript from human fetal brain (EST02625). Northern blot analysis of fox testis RNA samples identified an RNA transcript of approximately 0.9 kb during the months when spermatogenesis is active. Zoo Northern blots (at high stringency) reveal an RNA transcript of a similar size present in testis RNA from dogs and mice. Zoo Southern analysis (high stringency) reveal genomic sequences present in dogs, mice, cattle and sheep. At present, the function of the FSA-1 gene product remains unknown, but it may play a role as a structural protein component of the acrosome.

Attitudes towards practice nurses--survey of a sample of general practitioners in England and Wales

Practice nursing has expanded rapidly since the 1990 contract for general practitioners. In 1990, a national survey was undertaken of the attitudes of a random sample of general practitioners towards practice nurses. Responses to the postal questionnaire were received from 41.9% of the 4800 general practitioners sampled. Of the responding general practitioners, 90.0% were satisfied with the role of the practice nurse within their practice. To fulfil the requirements of the 1990 contract for general practitioners 50.7% had created a new nursing post, and 83.1% had expanded the role of nurses already employed; 89.7% wished to see further expansion of the practice nurse's role. However, lack of space was the factor most frequently reported as limiting the expansion of the practice nurse's role, mentioned by 76.0% of general practitioners. Only 43.7% of general practitioners recognized lack of opportunities for practice nurse training as a hindrance to role expansion. The key to managing the expansion of the role of the practice nurse lies in the provision of resources and in training. A pressing need exists for a national training scheme based in general practice.

Association of exogenous DNA with cattle and insect spermatozoa in vitro

Spermatozoa isolated from domestic cattle (Bos taurus), the Australian sheep blowfly (Lucilia cuprina), and the honeybee (Apis mellifera) are capable of binding exogenous radiolabeled linear DNA. Both motile and nonmotile bovine sperm exhibit four distinct patterns of DNA association. Following treatment with DNase I, the relative proportion of one of these patterns increases specifically in living sperm, suggesting that a small proportion of DNA that associates with bovine sperm may be sequestered within the sperm head.

Exploratory project for development of nursing outcome criteria in long term care

This exploratory project in developing outcome criteria for long term care was conducted with the view that the individual professional nursing practitioner has a unique, valuable contribution to make to the overall nursing quality assurance effort. Twenty-seven nurses volunteered to design and conduct individual systematic nursing diagnosis/intervention/outcome measurement projects. They were employees of five long term care facilities in New York state. Their contribution to this project was an embodiment of their professional judgement and practice with 107 selected clients under their care. They were prepared for participation through instruction repeated in all five facilities. The North American Nursing Diagnosis Association's Taxonomy of Nursing Diagnoses was used in the instruction, by the practitioners in their practice and data collection, and in the data analysis. Data analysis also included use of Campbell's nursing intervention category scheme. This work demonstrated that professional nurses are able to specify appropriate outcome criteria and to measure these outcomes of their planned nursing interventions. Eighty-seven percent of the expected outcomes were achieved as anticipated or in the anticipated direction. Results provided many leads for future study of nursing diagnosis/intervention/outcome measurement among residents of long term care institutions.

19F N.M.R. SPECTRA OF HEPTAVALENT FLUORIDES AND OXIDE PENTAFLUORIDES

The 19F n.m.r. spectra of IF7, ReF7, IOF5, ReOF5, and OsOF5 have been recorded. IF7gives rise to a broad symmetric doublet with a splitting of 4 100 ± 300 c.p.s. interpreted as partially collapsed and unresolved 19F—127I coupling. ReF7 gives a single line of width 60 c.p.s. at low field. These spectra give no information about the molecular structure other than that there is a fast intramolecular process causing magnetic equivalence. IOF5 and ReOF5 both exhibit a quintet/doublet spectrum indicative of locked C4v symmetry. The multiplet splittings in IOF5 are not resolved in pure IOF5 or in IOF5/IF7 mixtures, but can be seen for IOF5 in solution in IF5. The doublet lies to higher field than the quintet in IOF5, but the reverse occurs in ReOF5. In the paramagnetic molecule OsOF5 only the resonance of the unique axial fluorine is observed, indicative of localization of the non-bonding d-electron in the equitorial plane of the molecule.

THE METAL-CATALYZED AUTOXIDATION OF TETRALIN: II. THE COBALT-CATALYZED AUTOXIDATION OF UNDILUTED TETRALIN AND OF TETRALIN IN CHLOROBENZENE

The catalysis of the autoxidation of tetralin by the cobalt salts of 10 organic acids has been examined at 50 °C over a concentration range from 2 × 10−6to 1.0 mole/l, of cobalt. The measured rate of oxidation reaches a limiting value at cobalt concentrations above 2 × 10−2mole/l., which is about half the expected limiting rate. The cobalt salt catalysts are deactivated during the oxidation, probably in the initiation reaction with hydroperoxide, each cobalt atom being capable of decomposing about 100 molecules of hydroperoxide. Upon correcting the measured limiting rate for cobalt deactivation and for the amount of tetralin consumed at the point where the rate reaches a maximum value an extrapolated limiting rate about equal to the expected value is obtained. Although no steady concentration of hydroperoxide occurs during the oxidation the results suggest that the limiting rate of oxidation is basically due to the same phenomena that produce a limiting rate for the cobalt-catalyzed autoxidation of tetralin in acetic acid (Y. Kamiya et al. Can. J. Chem. 41, 2020 (1963)).

THE METAL-CATALYZED AUTOXIDATION OF TETRALIN: I. INTRODUCTION. THE COBALT-CATALYZED AUTOXIDATION IN ACETIC ACID

The catalytic effect of transition metal salts on the rate of autoxidation of organic substances reaches a constant value at some critical catalyst concentration. Three possible explanations of this phenomena are critically examined. The cobalt acetate catalyzed autoxidation of tetralin in acetic acid has been reinvestigated and the limiting rate of oxidation at high cobalt concentrations has been shown to be due to the production of a steady-state concentration of hydroperoxide. The present results are in fair agreement with the experimental work of Woodward and Mesrobian (J. Am. Chem. Soc. 75, 6189 (1953)) and are in excellent agreement with theoretical predictions.