Hypothyroxinemia and weight velocity in preterm infants

OBJECTIVES

Hypothyroxinemia of prematurity (HOP) is characterized by low free thyroxine (FT4) associated with low or normal thyroid stimulating hormone (TSH). The objective of this study is to define FT4 and TSH values in very preterm infants (<32 weeks postmenstrual age, PMA) and correlate hypothyroxinemia and levothyroxine treatment with growth velocity at 28 days and 36 weeks PMA.

METHODS

Preterm neonates <32 weeks PMA admitted to the regional neonatal intensive care unit (NICU) at the Children's Hospital of Georgia (USA) between January 2010 and July 2022 were routinely screened for hypothyroxinemia. FT4 and TSH values were obtained on 589 eligible neonates between day of life (DOL) 4 and 14. Growth velocity (g/kg/day) from DOL 14 to DOL 28 and 36-weeks PMA were calculated for each neonate and potential explanatory variables (PMA, sex, and race) were incorporated into multivariate regression models to identify associations between HOP and growth velocity.

RESULTS

In 589 preterm infants, PMA at birth was strongly associated inversely with FT4 (R=0.5845) and modestly with TSH (R=0.2740). Both FT4 and gestational age, but not TSH or levothyroxine treatment, were associated with growth velocity at 28 days of life and at 36 weeks PMA.

CONCLUSIONS

We provide a large data set for identifying FT4 and TSH measurements and identify hypothyroxinemia of prematurity as a potential mediator of slow postnatal growth in very preterm infants.

Routine Diaper Change Alters Kidney Oxygenation in Premature Infants: A Non-A Priori Analysis

BACKGROUND

Reduction in oxygen delivery to developing kidneys of premature infants may be an important source for acute kidney injury in premature infants.

PURPOSE

To describe changes in continuous kidney oxygenation (RrSO 2 ) measures before, during, and after routine diaper changes.

METHODS

Non-a priori analysis of a prospective cohort that received continuous measurement of RrSO 2 with near-infrared spectroscopy (NIRS) over the first 14 days of life demonstrating acute RrSO 2 drops surrounding diaper changes.

RESULTS

In total, 26 of 38 (68%) infants (≤1800 g) from our cohort exhibited acute drops in RrSO 2 that temporally correlated with diaper changes. Mean (SD) RrSO 2 baseline prior to each diaper change event was 71.1 (13.2), dropped to 59.3 (11.6) during diaper change, and recovered to 73.3 (13.2). There was a significant difference between means when comparing baseline to diaper change ( P < .001; 95% CI, 9.9 to 13.8) and diaper change to recovery ( P < .001; 95% CI, -16.9 to -11.2). The mean decrease in RrSO 2 during diaper change averaged 12 points (17%) below 15-minute RrSO 2 mean prior to diaper change, with quick recovery to prediaper change levels. No decreases in SpO 2 , blood pressure, or heart rate were documented during the intermittent kidney hypoxic events.

IMPLICATIONS FOR PRACTICE AND RESEARCH

Routine diaper changes in preterm infants may increase the risk for acute reductions in RrSO 2 as measured by NIRS; however, the impact on kidney health remains unknown. Larger prospective cohort studies assessing kidney function and outcomes related to this phenomenon are needed.

1230 PALLIATIVE CARE MOVEMENT DISORDERS MULTIDISCIPLINARY MEETING

Introduction

It is well recognised that patients with Parkinson’s disease (PD) have significant symptom burden in advanced stages of their disease. Integration of movement disorder and palliative care services has been limited by concerns about resource and sustainability. We present our experience of establishing a movement disorders palliative care multidisciplinary meeting.

Method

In 2019 we established a multidisciplinary virtual bimonthly meeting between movement disorders and palliative care specialists. Referrals were accepted from movement disorder specialists, community Parkinson’s practitioners and palliative care specialists. Referring clinicians all actively applied primary palliative care approaches within their existing services. Aims of the meeting were to facilitate holistic management of complex needs, support advance care planning (ACP) and consider referral to specialist palliative care services.

Result

37 patients in total were discussed over a 2-year period (although the service was limited for a time due to COVID pressures). On average 3 new patients were discussed per meeting. Reasons for referral included motor and non-motor symptoms, support with ACP, medication advice, caregiver concerns and emotional distress. Meeting outcomes included medication adjustments, expediting reviews, hospice support, carer support, and referral to other services. Since the meetings started 23 (62%) patients have died. Of these, 30% died in hospital compared with the national average of 43.4%. The average between discussion at the meeting and death was 139 days. The meeting has generated education opportunities, triggered joint assessments and a professionals’ framework for the palliative management of patients with a movement disorder.

Conclusions

We present the experience of an MDT embedded within an early integrated palliative care service for movement disorders. The MDT has strengthened partnership working and findings suggest that alongside active primary palliative care, specialist palliative care for PD can be sustainable and resource efficient in a UK setting.

The role of technical assistance in expanding access to Xpert(®) MTB/RIF: experience in sub-Saharan Africa

To improve tuberculosis (TB) diagnosis, many national TB programmes have committed to deploying Xpert(®) MTB/RIF. Implementation of this relatively new technology has suffered from a lack of comprehensive technical assistance, however, including the formulation of policies and plans to address operational issues. While providing technical assistance, we observed numerous operational challenges in the implementation and scale-up of Xpert in five sub-Saharan African countries: low coverage, poor laboratory infrastructure, limited access, poor linkages to treatment, inadequate data on outcomes, problems with specimen transport, diagnostic algorithms that are not aligned with updated World Health Organization recommendations on target patient groups and financing challenges. We recommend better country preparedness and training, laboratory information and quality systems, supply management and referral mechanisms.

Excess BMP Signaling in Heterotopic Cartilage Forming in Prg4-null TMJ Discs

Heterotopic cartilage develops in certain pathologic conditions, including those affecting the human temporomandibular joint (TMJ), but the underlying molecular mechanisms remain obscure. This is in part due to the fact that a reliable animal model of such TMJ diseases is not available. Here, we show that aberrant chondrocyte differentiation and ectopic cartilage formation occur spontaneously in proteoglycan 4 (Prg4) mutant TMJ discs without further invasive procedure. By 2 mo of age, mutant disc cells displayed chondrocyte transdifferentiation, accompanied by strong expression of cartilage master gene Sox9 and matrix genes aggrecan and type II collagen. By 6 mo, heterotopic cartilage had formed in the discs and expressed cartilage hypertrophic markers Runx2 and ColX. The ectopic tissue grew in size over time and exhibited regional mineralization by 12 mo. Bone morphogenetic protein (BMP) signaling was activated with the ectopic chondrogenic cells and chondrocytes, as indicated by phosphorylated Smad 1/5/8 nuclear staining and by elevated expression of Bmp2, Bmpr1b, Bmpr2, and BMP signaling target genes. Likewise, we found that upon treatment with recombinant human BMP 2 in high-density micromass culture, mutant disc cells differentiated into chondrocytes and synthesized cartilage matrix more robustly than control cells. Importantly, a specific kinase inhibitor of BMP receptors drastically attenuated chondrogenesis in recombinant human BMP 2-treated mutant disc cultures. Unexpectedly, we found that Prg4 was expressed at joint-associated sites, including disc/muscle insertion and muscle/bone interface, and all these structures were abnormal in Prg4 mutants. Our data indicate that Prg4 is needed for TMJ disc integrity and function and that its absence leads to ectopic chondrogenesis and cartilage formation in conjunction with abnormal BMP signaling. Our findings imply that the BMP signaling pathway could be a potential therapeutic target for prevention or inhibition of ectopic cartilage formation in TMJ disease.

Comparison of audio vs. written feedback on clinical assignments of nursing students

AIM

This pilot study explored using audio recordings as method of feedback for weekly clinical assignments of nursing students.

BACKGROUND

Feedback that provides students with insight into their performance is an essential component of nursing education. Audio methods have been used to communicate feedback on written assignments in other disciplines, but this method has not been reported in the nursing literature.

METHOD

A survey and VARK questionnaire were completed by eight nursing students. Each student had randomly received written and audio feedback during an eight-week period.

RESULTS

There were no differences between written and audio methods. Students perceived audio as the most personal, easy to understand, and positive method. Only one student expressed a preference for written feedback.There was no difference in instructor time.

CONCLUSION

Audio feedback is an innovative method of feedback for clinical assignments of 'Net Generation' nursing students.

Sulfotransferase Ndst1 is needed for mandibular and TMJ development

Heparan sulfate proteoglycans (HS-PGs) regulate several developmental processes, but their possible roles in mandibular and TMJ formation are largely unclear. To uncover such roles, we generated mice lacking Golgi-associated N-sulfotransferase 1 (Ndst1) that catalyzes sulfation of HS-PG glycosaminoglycan chains. Ndst1-null mouse embryos exhibited different degrees of phenotypic penetrance. Severely affected mutants lacked the temporomandibular joint and condyle, but had a mandibular remnant that displayed abnormal tooth germs, substandard angiogenesis, and enhanced apoptosis. In mildly affected mutants, the condylar growth plate was dysfunctional and exhibited thicker superficial and polymorphic cell zones, a much wider distribution of Indian hedgehog signaling activity, and ectopic ossification along its lateral border. Interestingly, mildly affected mutants also exhibited facial asymmetry resembling that seen in individuals with hemifacial microsomia. Our findings indicate that Ndst1-dependent HS sulfation is critical for mandibular and TMJ development and allows HS-PGs to exert their roles via regulation of Ihh signaling topography and action.

Indian hedgehog roles in post-natal TMJ development and organization

Indian hedgehog (Ihh) is essential for embryonic mandibular condylar growth and disc primordium formation. To determine whether it regulates those processes during post-natal life, we ablated Ihh in cartilage of neonatal mice and assessed the consequences on temporomandibular joint (TMJ) growth and organization over age. Ihh deficiency caused condylar disorganization and growth retardation and reduced polymorphic cell layer proliferation. Expression of Sox9, Runx2, and Osterix was low, as was that of collagen II, collagen I, and aggrecan, thus altering the fibrocartilaginous nature of the condyle. Though a disc formed, it exhibited morphological defects, partial fusion with the glenoid bone surface, reduced synovial cavity space, and, unexpectedly, higher lubricin expression. Analysis of the data shows, for the first time, that continuous Ihh action is required for completion of post-natal TMJ growth and organization. Lubricin overexpression in mutants may represent a compensatory response to sustain TMJ movement and function.

Yet another degree for the nursing profession

As a current Doctorate of Nursing Practice (DNP) student at the Medical College of Georgia (pilot program) and a neonatal nurse practitioner, I was disturbed by the editorial in the July/August 2005 edition of Neonatal Network® entitled “Yet Another Degree for the Nursing Profession,” and would like to express a different point of view.

Evaluation and costs of different haemoglobin methods for use in district hospitals in Malawi

AIMS

To evaluate the characteristics of manual haemoglobin methods in use in Malawi and provide evidence for the Ministry of Health in Malawi to enable them to choose a suitable method for district hospitals.

METHODS

Criteria on accuracy, clinical usefulness, user friendliness, speed, training time, and economic costs were determined by local health professionals and used to compare six different manual haemoglobin methods. These were introduced sequentially into use in a district hospital in Malawi alongside the reference method.

RESULTS

HemoCue was the optimal method based on most of the outcome measures but was also the most expensive (0.75 US dollars/test). DHT meter and Jenway colorimeter were the second choice because they were cheaper (0.20-0.35 US dollars/test), but they were not as accurate or user friendly as HemoCue.

CONCLUSIONS

The process for choosing appropriate laboratory methods is complex and very little guidance is available for health managers in poorer countries. This paper describes the development and testing of a practical model for gathering evidence about test efficiency that could be adapted for use in other resource poor settings.

Serological and molecular screening for viruses in blood donors from Ntcheu, Malawi: high prevalence of HIV-1 subtype C and of markers of hepatitis B and C viruses

The prevalence of antibodies to human immunodeficiency virus type 1 (HIV-1), hepatitis C virus (HCV), human T lymphotropic virus I (HTLV-I), and hepatitis B (HBV) surface antigen (HBsAg) was determined in blood donors from Ntcheu, Malawi. Each donation was also screened for HIV-1 RNA and HCV RNA. Among 159 blood donations, the prevalence of HIV-1 infection was 10.7%, 8.1% for HBV carriage, 6.8% for anti-HCV, and 2.5% for anti-HTLV-I. HIV-1/HTLV-I and HIV-1/HCV dual infections were observed in 1.2% of the donations. Consequently, 13% of blood donors from Ntcheu should be deferred for retroviral infections and 15% for hepatitis viral infections. Sequence analyses of the HIV-1 strains revealed a relatively homogeneous circulation of subtype C viruses in Malawi. These findings confirm the high endemicity of blood-borne viruses in Malawi and the need for a sensitive viral screening of blood donations to improve blood safety.

Use of clinical judgement to guide administration of blood transfusions in Malawi

The aim of this study was to investigate whether clinicians in Malawi could use clinical judgement alone to administer blood transfusions in accordance with guidelines. Clinicians at a district hospital did not use the Lovibond Comparator haemoglobin results provided by their laboratory as they felt them to be unreliable, preferring instead to rely on their clinical judgement alone to guide transfusion practice. Their transfusion practice and the Lovibond haemoglobin results were monitored against the World Health Organization recommended haemiglobincyanide method for haemoglobin measurement without the clinicians having access to this result. The Lovibond Comparator method was shown to have a sensitivity of only 21% to detect trigger haemoglobin values for transfusion published in local guidelines. Without access to a useful haemoglobin result, clinicians gave 67% of transfusions in accordance with the haemoglobin trigger values in the guidelines. This study shows that clinical features alone can provide a reasonable guide about the need for transfusion, and that poor quality laboratory tests limit the effectiveness of transfusion guidelines.

The human genome project: a historical perspective

Efforts in genomics over the last decade have created a stream of opportunities for drug discovery. High-throughput DNA sequencing has forced a re-definition of the paradigm for identification and validation of targets for drug development. One purpose of this review is to delineate the different approaches to sequence data generation and to establish their various uses for the definition of gene function. There still remain crucial dilemmas for the pharmaceutical industry. The multitude of potential targets can each absorb enormous validation costs and the vast majority are likely to prove academically interesting but useless for drug development. An additional dimension arises from the importance of sequence variation between different individuals. These differences can determine response to therapy and must inform both the drug development process and healthcare delivery. This presents great challenges and opportunities for drug companies, their customers and society as a whole. I will review the technological aspects in some detail and give my view of the legal and social aspects. The field of bioinformatics is at the core of functional and pharmacogenomics and advances will depend on the continuing evolution of tools to interpret data. For the most part this evolution is reviewed in the context of specific application areas rather than as a discrete field, in recognition of its all-pervasive effects.

Screening tuberculosis suspects using two sputum smears

SETTING

Ntcheu district hospital, Malawi.

OBJECTIVE

To assess a screening strategy for tuberculosis (TB) suspects using two sputum smears.

DESIGN

A strategy of screening all TB suspects with two sputum smears for 6 months (1 July-31 December 1998) was compared with the period 1 January to 30 June 1998 during which the strategy of screening TB suspects with three sputum smears was in use. All chest radiographs of patients with negative sputum smears were assessed, and in those with pulmonary cavities and extensive disease a third sputum smear was examined. Data were collected from the laboratory sputum register and the TB register. The two 6-month periods were compared.

RESULTS

In the laboratory register, using a two-sputum strategy, 186 (16%) of 1152 TB suspects were smear-positive, a result that was no different than when the three-sputum strategy was used, where 173 (16%) of 1106 TB suspects were smear-positive. The clinical pattern of TB using the different screening strategies was similar, with 58% of registered patients smear-positive with the two-sputum strategy and 54% smear-positive with the three-sputum strategy. In the first 6 months 3177 sputum smears were examined compared to 2266 smears in the second 6 months, a 29% reduction in the number of smears examined. The cost of consumables using the strategy of three sputum smears was USD $731 compared with USD $521 using the strategy of two sputum smears. C O N C L U S I O N S: Screening TB suspects using two sputum smears is as effective as screening using three sputum smears, and is associated with less laboratory work and savings in costs.

Roles of the "dispensable" portions of RAG-1 and RAG-2 in V(D)J recombination

V(D)J recombination is initiated by introduction of site-specific double-stranded DNA breaks by the RAG-1 and RAG-2 proteins. The broken DNA ends are then joined by the cellular double-strand break repair machinery. Previous work has shown that truncated (core) versions of the RAG proteins can catalyze V(D)J recombination, although less efficiently than their full-length counterparts. It is not known whether truncating RAG-1 and/or RAG-2 affects the cleavage step or the joining step of recombination. Here we examine the effects of truncated RAG proteins on recombination intermediates and products. We found that while truncated RAG proteins generate lower levels of recombination products than their full-length counterparts, they consistently generate 10-fold higher levels of one class of recombination intermediates, termed signal ends. Our results suggest that this increase in signal ends does not result from increased cleavage, since levels of the corresponding intermediates, coding ends, are not elevated. Thus, removal of the "dispensable" regions of the RAG proteins impairs proper processing of recombination intermediates. Furthermore, we found that removal of portions of the dispensable regions of RAG-1 and RAG-2 affects the efficiency of product formation without altering the levels of recombination intermediates. Thus, these evolutionarily conserved sequences play multiple, important roles in V(D)J recombination.

District sputum smear microscopy services in Malawi

SETTING

Government hospitals and health centres in 23 districts in Malawi.

OBJECTIVE

To determine 1) the number and smear-positivity rate of sputum samples submitted at health centres and hospitals, and 2) the time for sputum samples to get from health centres to smear examination.

DESIGN

Prospective data collection on sputum specimens coming from health centres to hospital laboratories, and over the equivalent time period, retrospective data collection from laboratory sputum registers.

RESULTS

Information was collected over a period of 5.6 months during 1997. Of 21 527 patients submitting sputum samples, 16995 (79%) were from within the hospital and 4532 (21%) were from health centres. Of 15 833 new TB suspects, 12 804 (81%) submitted sputum within the hospital and 3029 (19%) were from health centres. The overall smear-positivity rate was 11.9%: the proportion of new suspects who were smear-positive was significantly higher in health centres (14.1%) compared with hospital-based patients (11.4%, P < 0.05); 27% of all sputum specimens from health centres took 8 days or longer to get to smear examination. Sputum smears were positive from 1-30 days between submission and laboratory examination.

CONCLUSION

Fewer sputum samples are submitted at health centres compared with hospitals, and there may be long delays between sputum submission and smear examination. The precise reasons are unclear, but health centre staff need training about the importance of timely case finding procedures.

A high-resolution microsatellite map of the mouse genome

The European Collaborative Interspecific Backcross (EUCIB) resource was constructed for the purposes of high-resolution genetic mapping of the mouse genome (). The large Mus spretus/C57BL/6 backcross of 982 progeny has a genetic resolution of 0.3 cM at the 95% confidence level ( approximately 500 kb in the mouse genome). We have used the EUCIB mapping resource to develop a genome-wide high-resolution genetic map incorporating 3368 microsatellites. The microsatellites are distributed among 2302 genetically separated bins with 1.46 markers per bin on average. Average bin separation is 0.61 cM. This high-resolution genetic map will aid the construction of a robust physical map of the mouse genome.

High-throughput microsatellite analysis using fluorescent dUTPs for high-resolution genetic mapping of the mouse genome

The use of fluorescent end-labeled primers has proved successful for rapid, semiautomated genotyping of microsatellite loci. However, custom synthesis is expensive and costs can be prohibitive when a wide range of markers is to be analyzed for only a few genotypings. This particularly applies to high-resolution genetic mapping in the mouse either in the construction of global maps or in the production of local high-resolution genetic maps for positional cloning. We demonstrate here the use of fluorescent dUTPs for cost-effective, high-throughput microsatellite genotyping in the mouse. This alternative to the use of fluorescent end-labeled primers for semiautomated genotyping is potentially applicable to the construction of linkage maps in other species.

Role of the karyopherin pathway in human immunodeficiency virus type 1 nuclear import

The interaction of the human immunodeficiency virus type 1 (HIV-1) nucleoprotein complex with the cell nuclear import machinery is necessary for viral replication in macrophages and for the establishment of infection in quiescent T lymphocytes. The karyophilic properties of two viral proteins, matrix (MA) and Vpr, are keys to this process. Here, we show that an early step of HIV-1 nuclear import is the recognition of the MA nuclear localization signal (NLS) by Rch1, a member of the karyopherin-alpha family. Furthermore, we demonstrate that an N-terminally truncated form of Rch1 which binds MA but fails to localize to the nucleus efficiently blocks MA- but not Vpr-mediated HIV-1 nuclear import. Correspondingly, NLS peptide inhibits the nuclear migration of MA but not that of Vpr and prevents the infection of terminally differentiated macrophages by vpr-defective virus but not wild-type virus. These results are consistent with a model in which Rch1 or another member of the karyopherin-alpha family, through the recognition of the MA NLS, participates in docking the HIV-1 nucleoprotein complex at the nuclear pore. In addition, our data suggest that Vpr governs HIV-1 nuclear import through a distinct pathway.

A Portable, Discrete-Sampling Submersible Plankton Pump and Its Use in Sampling Starfish Eggs

The apparatus was designed to enable divers to obtain discrete replicate samples from known volumes of water. Relatively large volumes of water can be filtered without the need to maintain contact with or return to the surface. These attributes confer a high degree of flexibility in subsurface sampling situations. Although we used the equipment to sample the eggs of invertebrates, it could equally easily be used to sample other small, patchily distributed plankton.