Height-based formulas for predicting intravascular length of tunnelled neck central venous catheter in paediatric population

INTRODUCTION

Central venous catheter (CVC) placement is commonly performed in children. We aim to develop simple formulas to predict CVC intravascular length to minimise radiation exposure associated with the procedure.

METHODS

124 paediatric patients who received tunnelled neck CVCs and subsequent CT thorax at Hong Kong Children's Hospital from January 2020 to July 2022 were reviewed retrospectively. Formula development cohorts were subdivided by insertion sites-9 right external jugular vein (REJV), 41 right internal jugular vein (RIJV), 14 left external jugular vein (LEJV), 10 left internal jugular vein (LIJV). Using measurements from CT by two radiologists, formulas predicting the CVC intravascular length based on height and insertion sites were developed using a linear regression model. These formulas were tested with validation cohorts (10 randomly selected cases in REJV and RIJV groups respectively). Validation cohorts were not available for LEJV and LIJV groups due to small sample sizes.

RESULT

The goodness-of-fit (R^2) of all formulas are above 0.8. In the validation cohorts, the REJV formula was predictive of intravascular CVC length within 1 cm in 70% of CVC with mean absolute difference of 0.63 cm (SD 0.48 cm), and the RIJV formula was predictive of intravascular CVC length within 1 cm in 80% of CVC with mean absolute difference of 0.67 cm (SD 0.53 cm).

CONCLUSION

Intravascular CVC length can be estimated using simple formulas based on height and insertion sites. Further prospective validation of the LEJV and LIJV formulas is needed.

Comparison of central corneal thickness measurements using three different imaging devices

PURPOSE

The purpose of this study was to compare central corneal thickness (CCT) values and evaluate the agreement obtained with three different devices in healthy eyes.

METHODS

A total of 120 eyes of 60 healthy individuals (36 men and 24 women) were enrolled in this retrospective study. CCT measurements were performed using an optical biometer (AL-Scan), spectral-domain optical coherence tomography (SD-OCT) (Topcon 3D) and ultrasonic pachymetry (UP) (Accupach VI), and the results were compared. Bland-Altman analysis was used to quantify the agreement between methods.

MAIN RESULTS

The mean patient age was 28±5.73years (18-40years). The mean CCT values obtained by AL-Scan, UP, and SD-OCT were 532.4μm±29.7, 549μm±30.4, and 547μm±30.6, respectively. The mean differences in CCT were 15.30±9.52μm between AL-Scan and OCT (P<0.01), 17.15±8.42μm between AL-Scan and UP (P<0.01), and 1.85± 8.78μm between UP and OCT (P=0.067). All three methods of CCT measurement were closely correlated with each other.

CONCLUSION

The present study results suggest that, despite good agreement between the three devices, AL-Scan significantly underestimated CCT compared to UP and OCT. Therefore, clinicians should be aware that different results can be obtained using different devices for CCT measurements. It would be a better approach not to use them as interchangeable in clinical practice. CCT examination and follow-up should be performed using the same device, especially for patients who will undergo refractive surgery.

Cardiac structure and functions in patients with asymptomatic primary hyperparathyroidism

BACKGROUND

The data about cardiovascular (CV) changes in patients with asymptomatic primary hyperparathyroidism (PHPT) are scarce.

AIM

The aim of this study is to compare cardiac structure and functions in patients with asymptomatic PHPT and controls by using tissue Doppler echocardiography.

SUBJECTS AND METHODS

Thirty-eight patients with asymptomatic PHPT and 31 sex- and age-matched controls with similar cardiac risk factors were evaluated.

RESULTS

There was no significant difference in ejection fraction (EF) between the patients and the controls [64±5.95 vs 62±3.25% (p=0.094)]. Left ventricular mass index (LVMI) was significantly higher in patients than controls [105.96 (66.45-167.24) vs 93.79 (64.25- 139.25) g/m2, p=0.014]. There was a significant correlation between LVMI and serum calcium (Ca) (r=0.240, p<0.005). Myocardial performance index (MPI) was significantly higher in patients than controls [0.49 (0.35-0.60) vs 0.39 (0.33-0.62), p<0.001]. There was positive correlation between theMPI and serumCa levels (r=0.505, p<0.001), parathyroid hormone (PTH) levels (r=0.464, p<0.001) and LVMI (r=0.270, p<0.005). When the normotensive patients and controls were evaluated, the difference between the groups remained statistically significant considering LVMI and MPI [109 (66.45-167.24) g/m2 vs 94.17 (64.25-75.10) g/m2, p=0.03; and 0.49 (0.35-0.60) vs 0.39 (0.33-0.62), p<0.01, respectively]. There were significant correlations between MPI and Ca (r=0.566, p<0.001), and PTH (r=0.472, p<0.001).

CONCLUSIONS

Our study results showed that cardiacmorphology and diastolic functions are altered in the patients with asymptomatic PHPT. High serum PTH and Ca levels may have an impact on these CV changes. Whether these subtle CV changes would affect cardiac systolic functions and mortality in patients with asymptomatic PHPT should be investigated in further prospective studies.

Massive occult haemoperitoneum following spontaneous rupture of duodenal gastrointestinal stromal tumour

Gastrointestinal stromal tumours are an uncommon subset of mesenchymal tumour that can occur anywhere along the gastrointestinal tract. Diagnosis of gastrointestinal stromal tumours is often difficult, as presentation is variable. This case report identifies massive haemoperitoneum as an initial finding, which is an unusual mode of presentation in gastrointestinal stromal tumours.

Transport of living cells with magnetically assembled nanowires

We present a technique of transporting and positioning living cells internalized by nickel (Ni) nanowires guided by magnetic field. Nanoscale magnetic nanowires are internalized by the Rat Neuroblastoma (ATCC number CRL-2754) and the cells are transported and positioned by magnetic fields from the magnetic material-coated electrodes. This technique may enable the interfacing between neurons and electronic devices to empower investigations pertaining to non-invasive neuron probing as well as nanofabricated neural pharmacological technologies.

Normal Developmental Changes in Inferior Frontal Gray Matter Are Associated with Improvement in Phonological Processing: A Longitudinal MRI Analysis

This study asked whether previously identified developmental changes in the gray matter of the left inferior frontal gyrus are associated with maturation of a linguistic skill. To test this hypothesis, we examined whether thickening of this region was correlated with developmental improvements in phonological processing but not hand motor skills in a unique longitudinal data set of 45 normally developing children (between ages 5 and 11 years) studied over a 2-year interval. We analyzed structural magnetic resonance imaging data using cortical pattern matching methods and correlated within-individual changes in cortical thickness with 2 neurocognitive scores. As predicted, gray matter thickening in the left inferior frontal cortex was associated with improving phonological processing scores but not with improving hand motor skills. By contrast, motor skill improvement was associated with thinning in the hand region of the left motor cortex, and cortical change in this region was not associated with phonological processing. This study illustrates a specific correspondence between regional gray matter thickness change and language skill change in normally developing children.

Scale-up and cost evaluation of a foamed emulsion bioreactor

In the present paper, the potential of the foamed emulsion bioreactor (FEBR), a novel biological reactor for air pollution control was evaluated. Experimental data obtained on a laboratory-scale prototype were used to scale-up the process for a hypothetical case consisting of a contaminated air flow rate of 10,000 m(3) h(-1), a toluene inlet concentration of 1 g m(-3) and minimum required treatment efficiency of 92%. Reactor design and operating issues for the full-scale FEBR were identified. They included the requirement for stable foam generation with appropriate air distributors, and recycling of the auxiliary organic phase, surfactants and cells from the discharge of the reactor. The capital and operating costs for the concept full-scale FEBR were evaluated and compared to those of competing technologies, namely biofiltration, biotrickling filtration and catalytic and thermal oxidation. All three biological techniques had significantly lower capital and operating costs. Among the biological techniques, the FEBR had the lowest estimated capital cost since its greater effectiveness allowed a smaller reactor to meet the treatment objectives. The operating costs for the FEBR were higher than those of biofilters and biotrickling filters because of the requirements for nutrients and auxiliary chemicals. Overall, the results highlight that biotreatment is much more cost effective than thermal and catalytic oxidation. They further suggest that the FEBR may an interesting alternative to biofilters and biotrickling filters where the available space for air pollution control equipment is limited.

Activation of purified cardiac ryanodine receptors by dihydropyridine agonists

Prior observations have raised the possibility that dihydropyridine (DHP) agonists directly affect the sarcoplasmic reticulum (SR) cardiac Ca(2+) release channel [i.e., ryanodine receptor (RyR)]. In single-channel recordings of purified canine cardiac RyR, both DHP agonists (-)-BAY K 8644 and (+)-SDZ202-791 increased the open probability of the RyR when added to the cytoplasmic face of the channel. Importantly, the DHP antagonists nifedipine and (-)-SDZ202-791 had no competitive blocking effects either alone or after channel activation with agonist. Thus there is a stereospecific effect of SDZ202-791, such that the agonist activates the channel, whereas the antagonist has little effect on channel activity. Further experiments showed that DHP agonists changed RyR activation by suppressing Ca(2+)-induced inactivation of the channel. We concluded that DHP agonists can also influence RyR single-channel activity directly at a unique allosteric site located on the cytoplasmic face of the channel. Similar results were obtained in human purified cardiac RyR. An implication of these data is that RyR activation by DHP agonists is likely to cause a loss of Ca(2+) from the SR and to contribute to the negative inotropic effects of these agents reported by other investigators. Our results support this notion that the negative inotropic effects of DHP agonists result in part from direct alteration in the activity of RyRs.

Structure-activity relationships in platelet-activating factor (PAF). 10. From PAF antagonism to inhibition of HIV-1 replication

Excessive levels of PAF and cells of macrophage lineage appear to play an important role in neuronal cell injury, inflammatory syndrome, and HIV replication in CNS resulting in AIDS dementia complex (ADC). The beneficial effects of PAF receptor antagonists are evident and give rise to expected therapeutic strategies for neurotrauma. Piperazine derivatives bearing a "cache-oreilles" (ear-muff) electronic distribution are able to inhibit in vitro PAF effects and, thus, could be used in pathologies where this mediator is involved. Therefore, their potential anti-HIV activity was investigated, and we find that (i) these PAF antagonists are effectively active in HIV-infected monocyte-derived macrophages (MDM) but there is no correlation between both anti-HIV and anti-PAF activities; (ii) the presence of a carbamate function (compounds 1a-d) is favorable to the antiviral activity; (iii) the lipophilicity of the substituent on the piperazinic cycle seems to be less important for the anti-PAF activity than for the antiviral one. Our leading compound, PMS 601 (compound 1a), presents a dual activity with IC(50) of 8 and 11 microM for anti-PAF and anti-HIV activity, respectively, without cytotoxic events at 1000 microM in MDM. Although its mode of action is not clearly defined, these data suggest that PMS 601, which displays no effect on acellular reverse transcriptase or protease tests, deserves further investigation in the treatment of HIV-1-associated dementia.

An Action Research Study into the Development of Nurses as Reflective Practitioners

This study adopted an action research approach in addressing the question: How could nurses be prepared to be reflective practitioners? The study took place among a group of registered nurses who enrolled in the first year of their degree studies at the Hong Kong Polytechnic University. The methods of data collection included observation, interview, students' written material, and teacher reflection. The experience of this study suggested that teachers and students should be partners in the promotion of reflective learning among students. As teachers reflected on their teaching arrangement and the progress of student learning, students could accordingly be offered appropriate guidance. Throughout the span of their studies, students learned to gradually develop different perspectives in viewing professional nursing practice. The reconceptualization of nursing practice helped students challenge taken-for-granted views and eventually reconstruct their conception of nursing.

Multicenter study with recombinant human erythropoietin

A multicenter study with recombinant human erythropoietin (rh-EPO) was carried out. Of 172 hemodialysis patients with anemia selected for the study from 20 hospitals and clinics, 77 were males and 95 females (mean age 53.9 years). A starting dose of 1,500 U of rh-EPO (Epoetin beta) was administered intravenously at the end of every dialysis session. If the efficacy was not acceptable, the dose was increased to 3,000 U. When the target hematocrit was achieved (30%), the total dose was decreased. The results of the study were excellent relative to those of other multicenter studies with regard to efficacy, safety, and changes in laboratory data. The incidence of hypertension was lower in our study compared with other reports because we used a low initial dose. The efficacy of rh-EPO therapy was determined earlier and more reliably by reticulocytes than by hematocrit or hemoglobin. Prompt iron supplement therapy is recommended with careful observation of serum iron and ferritin.

EPO test in hemodialysis patients

It is well known that red blood cell (RBC) and reticulocyte counts increase when anemic hemodialysis patients receive repeated administrations of recombinant human erythropoietin(rh-EPO). However, the early response of reticulocyte has not been reported precisely. In this study, reticulocyte counts and its fractions were observed in 8 maintenance hemodialysis patients after a single intravenous administration of 60 u/Kg of rh-EPO. The peripheral blood cells taken from the patients were stained with auramine 0, which bound to RNA and caused fluorescence. R-1000 (Sysmex, Kobe, Japan) analyzed the reticulocytes and classified the stained cells into three groups by the intensity of fluorescence. The number of highly fluorescent reticulocyte, which was young and large, increased and reached its highest level on day 4 after a single administration of rh-EPO. The reticulocyte counts paralleled these changes, but RBC counts did not change after administrations of rh-EPO. These data suggest that the observation of reticulocytes and its fractions in hemodialysis patients after a single administration of rh-EPO could tell us whether reticulocytes are responsive to rh-EPO or not, and this could be called as EPO test.

[Case report: a foreign body (gauze) in the bladder]

A case of bladder tamponade caused by a foreign body (gauze) in the bladder of a 24-year-old man is reported. He had been treated with the Lambotte wire and screw to repair his pubic bone fracture caused by a traffic accident. About one year later, the wire and screw were removed from the patient. However, he suffered from gross hematuria and bladder tamponade on the 11th day after the 2nd operation, and he was transferred to our outpatient department on emergency. Further urological examinations were done for this case. The patient was diagnosed as having bladder tamponade caused by a foreign body, a gauze, in the bladder. Among these examinations NMR-CT gave us the most interesting and useful findings. NMR-CT showed that the gauze penetrated the bladder wall.