Integrated Experimental and Mathematical Exploration of Modular Tissue Cultures for Developmental Engineering

Developmental engineering (DE) involves culturing various cells on modular scaffolds (MSs), yielding modular tissues (MTs) assembled into three-dimensional (3D) tissues, mimicking developmental biology. This study employs an integrated approach, merging experimental and mathematical methods to investigate the biological processes in MT cultivation and assembly. Human dermal fibroblasts (HDFs) were cultured on tissue culture plastics, poly(lactic acid) (PLA) discs with regular open structures, or spherical poly(methyl methacrylate) (PMMA) MSs, respectively. Notably, HDFs exhibited flattened spindle shapes when adhered to solid surfaces, and complex 3D structures when migrating into the structured voids of PLA discs or interstitial spaces between aggregated PMMA MSs, showcasing coordinated colonization of porous scaffolds. Empirical investigations led to power law models simulating density-dependent cell growth on solid surfaces or voids. Concurrently, a modified diffusion model was applied to simulate oxygen diffusion within tissues cultured on solid surfaces or porous structures. These mathematical models were subsequently combined to explore the influences of initial cell seeding density, culture duration, and oxygen diffusion on MT cultivation and assembly. The findings underscored the intricate interplay of factors influencing MT design for tissue assembly. The integrated approach provides insights into mechanistic aspects, informing bioprocess design for manufacturing MTs and 3D tissues in DE.

P-375 Optimising vaginal biospecimen collection

Study question

Are menstrual tampons an acceptable and comparable method to lower vaginal swabs (LVS) for analysing the vaginal microbiome in non-pregnant women?

Summary answer

Tampons capture a higher bacterial load, volunteers are familiar with them, thus are well-accepted, and can be efficiently frozen at -20 °C prior to analysis.

What is known already

The vaginal microbiome plays a key role in women’s reproductive health. The application of investigating this niche allows a greater understanding of the impact of the vaginal microbiota in diverse reproductive disorders including infertility, recurrent miscarriage, spontaneous preterm birth and sexually transmitted infections. Fear and embarrassment related to physicians taking a traditional vaginal swab using a speculum results in many female genitourinary health appointments to be missed in the UK and recruitment challenges into vaginal microbiota research studies. Growing evidence suggests a menstrual tampon to be a superior alternative biospecimen collection device to a vaginal swab.

Study design, size, duration

This was a prospective, cross-sectional observational study. Twenty-one healthy volunteers (average age 30 years) were recruited over a period of 6 weeks at the Centre for Women's Health Research, University of Liverpool, an academic, tertiary referral centre.

Participants/materials, setting, methods

The volunteers consented to wearing a tampon for 20 minutes, taking 2 LVS and completing an acceptability questionnaire. Samples were halved for immediate processing and freezing at -20 °C for 2-4 weeks. Real-time PCR using Femoflor-16 was carried out to identify microorganisms present in vaginal microbiota. Microbiota was classified by total bacterial mass and relative abundance of lactobacillus species. Statistical analysis was carried out using GraphPad PRISM 5, Microsoft Excel 2019 and IBM SPSS Statistics 27.

Main results and the role of chance

Of the 84 samples, four had insufficient material for the purpose of analysis. Three of these were LVS samples and the fourth was a frozen tampon sample.

Mean tampon total bacterial mass was higher for fresh and frozen samples versus the mean LVS total bacterial mass.

The Femoflor algorithm gave identical vaginal microbiota characterisation between the fresh tampon and fresh LVS in 68.4% (13/19) of cases. 92% (12/13) samples with over 80% relative abundance of lactobacillus in the LVS also had over 80% relative abundance in the tampon. More discrepancy was seen between samples within the 20-80% and <20% relative abundance groups of lactobacillus in the LVS with 50% and 75% different classifications respectively. Importantly, only one case showed an LVS with lactobacillus >80% (normal) and a tampon with non-dominance of lactobacillus (<80%, dysbiosis).

The questionnaires revealed that 90.5% of the volunteers highly rated using tampons (3 or more out of 5 on a Likert scale), with 52.4% rating tampon-use at 5/5. All participants (100%) stated that they would be happy to provide a tampon sample for clinical/research testing purposes in the future.

Limitations, reasons for caution

This study included 21 healthy volunteers; this is not necessarily representative of the entire UK population, but the tampon and LVS from the same volunteer were consistently comparable before and after freezing. We used a multiplex PCR assay to target common vaginal bacteria, inevitably some bacteria have not been characterised.

Wider implications of the findings

Self-collected tampons are suitable, well accepted biospecimen collection devices that may reduce barriers posed due to embarrassment, improve attendance in genitourinary medicine clinics and encourage participation in vaginal microbiota research. Freezing before processing reduces time and costs. A large study is necessary to ensure reproducibility and acceptability to patient population.

Trial registration number

Not Applicable

Self-Collected Oral Fluid and Nasal Swab Specimens Demonstrate Comparable Sensitivity to Clinician-Collected Nasopharyngeal Swab Specimens for the Detection of SARS-CoV-2

We compared self-collected oral fluid swab specimens with and without clinician supervision, clinician-supervised self-collected mid-turbinate (nasal) swab specimens, and clinician-collected nasopharyngeal swab specimens for the detection of SARS-CoV-2. Supervised oral fluid and nasal swab specimens performed similarly to clinician-collected nasopharyngeal swab specimens. No sample type could detect SARS-CoV-2 infections amongst all positive participants.

Introducing PEEP: The psychiatry early experience programme

At Guy's King's and St Thomas’ School of Medicine, a unique initiative is the Psychiatry Early Experience Programme (PEEP), which allows students to shadow psychiatry trainees at work several times a year. The students’ attitudes towards psychiatry and the scheme are regularly assessed and initial results are already available.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

[Cutaneous foreign body granulomas following cervico-facial arterial embolization: Three cases]

BACKGROUND

Foreign body granuloma is an inflammatory tissue reaction to exogenous material. Classically it appears on the face after aesthetic procedures. Herein we report for the first time three cases of facial granulomatous reactions to microbeads after arterial cervico-facial embolization.

PATIENTS AND METHODS

Three patients underwent embolization of the facial arteries using Embogold^® microbeads in a setting of epistaxis or tumoral hemostasis. Within 10 to 45 days painful, inflammatory, subcutaneous nodules appeared on the homolateral side of the face. Histological samples showed an inflammatory response with giant cells as well as the presence of microbeads in the skin. A favorable outcome was achieved with colchicine in one patient and with surgery in another; the third patient was lost to follow-up.

DISCUSSION

The embolizing microspheres produced a local inflammatory reaction, with destruction of the vascular wall and bead migration to facial tissue leading to a granulomatous reaction. The occurrence of three cases within a period of few weeks, with several different operators and batches of products, is surprising considering the long-standing use of the product. There was no common comorbidity in the patients and no suggestion of trauma. Retrospective analysis of the product batches was normal. Gold staining could play a role in severe inflammatory response to Embogold^® particles.

CONCLUSION

These three cases illustrate the value of discussing potential foreign body granulomatous reaction in cases of facial nodules following cervico-facial embolization. Colchicine may offer a valuable therapeutic alternative.

Management of vascular malformations of the parotid area

OBJECTIVES

To describe our experience in the management of vascular malformations of the parotid area.

MATERIALS AND METHODS

This was a retrospective study. Among 614 parotidectomy performed between 1998 and 2008 at our institution, 10 cases (1.6%) of vascular malformations have been identified. Clinical features and management of these patients were analyzed.

RESULTS

Clinical presentation was usually related to that of a benign, slow-growing and asymptomatic tumor. There was a marked female predominance (90%). In any case, the diagnosis of vascular malformation could be obtained with certainty preoperatively. Surgical excision was performed most often referred to diagnosis. Sixty percent of vascular malformations were located in the superficial lobe of the parotid gland. On the histological we found a classic look with benign vascular proliferation of endothelial cells in the walls. The vessel lumen was either the head of a congestion or thrombosis or calcification (phleboliths).

CONCLUSION

Vascular malformations of the parotid gland, rare disease, are mainly venous. The terminology is based on clinical data, scalable, histological and hemodynamic as classified by the International Society of Study of Vascular Anomaly (ISSVA). Despite advances in imaging including MRI they remain difficult to diagnose. The treatment of reference is surgical excision.

Fine-needle aspiration cytology in the management of parotid masses: evaluation of 249 patients

INTRODUCTION

The role of fine-needle aspiration cytology (FNAC) in the management of parotid tumours is still the subject of controversy. The purpose of this study was to determine the diagnostic value of FNAC in our institution in order to define its place in the diagnostic strategy.

PATIENTS AND METHODS

This retrospective study was based on 249 patients who had undergone preoperative FNAC before being operated in our institution between 2001 and 2008. All examinations were performed and interpreted by the same experienced pathologist.

RESULTS

Among the 249 patients included in this study, 187 (75%) had a benign tumour and 62 (25%) had a malignant tumour. No complications of FNAC were observed. Cytological findings were non-contributory in 47 patients (18%). The sensitivity of FNAC for the diagnosis of malignancy was 80% with a specificity of 89.5%. Among the 11 false-negative results, lymphomas and low-grade mucoepidermoid carcinomas were the most common histological types. Among the 16 false-positive results, Warthin's tumours, pleomorphic adenomas and lymphoepithelial lesions were the most common histological types. Accurate histological classification of the tumour was reported in 79.5% of cases (86% for benign tumours and 44% for malignant tumours).

CONCLUSION

FNAC is a reliable examination providing important information to the surgeon in the preoperative diagnostic assessment.

[Mucoepidermoid carcinomas of salivary glands: prognostic significance of immunohistochemistry. A study of 49 cases]

INTRODUCTION

Mucoepidermoid carcinoma (MEC) is considered as the most common malignant salivary gland tumor. Its prognosis is dominated by the presence of high-grade forms involving life-threatening. The aim of our study was to evaluate the usefulness of immunohistochemistry to identify the most aggressive forms and allow better discrimination between low grade, intermediate grade and high grade tumors.

MATERIALS AND METHODS

This was a retrospective study of 49 cases of mucoepidermoid carcinomas of salivary glands. Two immunohistochemical markers have mainly been studied: a marker of proliferation (Ki-67) and a growth factor receptor (EGFR). Additional analyzes were performed with other markers (p53, ACE, bcl2, CD 117 and her2). Statistical analysis investigated the existence of a correlation between the presence of these factors and the histopathological grade on one hand and survival of patients on the other hand.

RESULTS

Regarding the results of immunohistochemical Ki-67 and EGFR, it was observed a better survival rate when the immunostaining was less than 10%. The expression of Ki-67 and EGFR was correlated with the histological grade, but did not, in our study, allow discrimination between low-grade, intermediate grade and high grade. Our results are consistent with data of the literature, including Ki-67, which appears to be a useful but not powerful marker of prognosis of MEC. Other markers studied (p53, ACE, bcl2, CD 117 and her2) showed no contributory results.

CONCLUSION

The prognosis of MEC is appreciated satisfactorily following histological criteria: histological grade, surgical margins, perineural invasion or vascular emboli. The integration of immunohistochemistry in a therapeutic algorithm could be particularly useful for the challenging assessment of prognosis of intermediate grades.

Direct test of laser tunneling with electron momentum imaging

Tunneling is often used to describe multiphoton ionization of rare gas atoms in infrared fields. We test the tunneling approximation and its nonadiabatic extension by measuring the unperturbed momentum distribution along the κ direction of a circularly polarized light pulse. We find substantial, but not total, agreement between our results and the predictions of the model. As predicted, the κ direction momentum distribution is Gaussian and its width increases with the square root of electric field strength. However, the width is 15% too large and we find no evidence of nonadiabatic effects as we approach the expected limits of the approximation.

A schwannoma of the hypoglossal nerve presenting as a malignant tumour of the oral floor

OBJECTIVES

We describe a case of an unusual schwannoma of the hypoglossal nerve presenting clinically as a malignant tumour of the floor of the oral cavity.

CASE REPORT

A 77-year-old woman presented with a bulky tumour located between the left anterior floor of mouth and the ventricular portion of the tongue. The tumour was ulcerated, painful and presented with a necrotic aspect. Neurological examination revealed a mild left hemiparesis of the tongue. MRI and CT showed a circumscribed tumour with a broad necrotic centre. The patient underwent a transoral excision of the tumour under general anaesthesia.

CONCLUSION

Schwannomas are generally managed by complete surgical excision but they can mimic primary or metastatic cancer in the head and neck, preoperative diagnosis is therefore necessary to avoid a wide excision.

[Role of diffusion weighted MR in the diagnosis of parotid tumours]

OBJECTIVE

To evaluate the contribution of sequences of diffusion for the diagnosis of nature of the tumours of the parotid.

METHODS

Retrospective study based on 29 patients all operated of a parotid tumour They had a MRI in conventional acquisition (T1, T1 Gadolinium, T2) and in sequences of diffusion. An ADC cartography (apparent coefficient of diffusion) and an ADC ratio between the tumoral area and the healthy controlateral parotid were successively analyzed by two experienced radiologists. We calculated the effectiveness of these MRI sequences, focusing more particularly on the diagnosis of the malignant tumours. We also determined the sensitivity and the specificity of the sequences of diffusion, with their positive and negative predictive values.

RESULTS

On the 7 malignant tumours, 3 had been classified wrongly like benign thanks to the only cartography of diffusion. We obtained a sensitivity of this examination for the diagnosis of malignity of 57%. Out of the 22 benign tumours, 1 only was classified wrongly like malignant. The specificity of the diffusion for the diagnosis of malignity thus rose with 95%, its positive predictive value with 80% and its negative predictive value to 87%. It should be noted that all the malignant tumours had an ADC ratio lower or equal to 1.8.

CONCLUSIONS

The histological characteristics of the malignant tumours of the parotid are very variable. Generally, they have large nuclei associated with a hypercellularity involving a decrease of the ADC. The results of this MRI sequence are encouraging even if they remain not very reliable in front of cystic or necrotic tumours.

[Remodeling of the nasal lobule using cartilaginous grafts on tip projection]

OBJECTIVES

Nasal tip projetion and definition are essential parameters which should be considered in the preoperative rhinoplasty plan. Jonhson and Toriumi have defined a technique of rhinoplasty to restructure the lobule using columellar strut and tip grafts. The aim of this study was to define the influence of this procedure on nasal tip projection, using the Goode method (objective measurement of the tip projection).

METHODS

Forty patients underwent primary rhinoplasty, by open approach, with remodeling of the lobule using cartilagenous grafts, according to Jonhson and Torium technique. Goode ratio was calculated to assess tip projection preoperatively and postoperatively, based on photographic analysis. Moreover, postoperatively, all patients were clinically evaluated at 2, 4 and 6 months, and based on photographs of face at 2 and 6 months.

RESULTS

Five hypoprojected preoperative nasal tips (Goode ratio (GR): 0,45 to 0,51) had a normal nasal tip projection postoperatively (GR: 0,55 to 0,59). Among the eight normal projected preoperative nasal tips (GR: 0,56 to 0,60), six had a normal postoperative nasal tip projection while two showed a hyperprojection (GR: 0,62 and 0,63). Among the 27 hyperprojected preoperative nasal tips (GR: 0,62 to 0,75), 17 showed a normal projection of the nasal tip postoperatively while 10 remained hyperprojected despite a decreased Goode ratio.

CONCLUSION

Restructuration of the lobule, using cartilagenous grafts, is a reliable and reproducible technique allowing satisfying aesthetic results and objective measurements of the changes in nasal tip projection using the Goode method.

Association of topoisomerase-1 (Topo1) with the efficacy of chemotherapy in a randomized trial for advanced colorectal cancer patients (FOCUS)

10009

Background: We have assessed potential predictive markers of the efficacy of irinotecan and oxaliplatin in advanced CRC patients randomized to fluorouracil (FU), FU+irinotecan (Ir) or FU+oxaliplatin (Ox). Methods: Pathology specimens were retrieved from 1281 patient in the FOCUS trial (ASCO 05 #3518). Normal and tumor DNA were extracted and tissue microarrays were made for immunohistochemistry (IHC). The following factors were assessed for effect on failure-free survival (FFS) with first-line therapy: IHC for MLH1, MSH2, P53, Topo1, ERCC1, MGMT, and COX2; DNA polymorphisms in GSTP1 (105Val), ABCB1 (C3435T), XRCC1 (Q399R), ERCC2 (K751Q), and UGT1A1*28. Results: Among 823 patients assessable for Topo1 IHC, we observed highly significant heterogeneity (interaction) of treatment effect in relation to Topo1 staining intensity (p=0.008, see table). 489 patients (59%) had moderate or high Topo1 expression; these patients derived highly significant benefit from 1st-line chemotherapy with either Ir or Ox. In contrast, the 334 (41%) patients with low Topo1 IHC expression showed no evidence of benefit from the addition of either Ir or Ox compared with FU alone (HR 1 and 0.9 respectively). When patients receiving FU alone are considered separately, low Topo1 expression was associated with significantly better FFS (HR 0.7 (0.6–0.9)). The other 11 molecular markers showed no significant interactions with treatment received (p values for interaction all > 0.1). Conclusions: We have identified a subgroup of 41% patients (with low Topo1 expression) for whom treatment outcome with FU alone is superior, but who appear to gain no benefit from the addition of Ir or Ox. We believe this to be the first demonstration in a large randomized trial of a genuinely predictive molecular marker. If verified in an independent dataset, this information could be used to select patients who can be safely treated with FU alone, or together with alternative additional agents.

[Table: see text]

No significant financial relationships to disclose.

Prognostic value of thymidylate synthase (TS) expression on failure-free survival of fluorouracil-treated metastatic colorectal cancer patients

10011

Background: We previously presented (ASCO 04 #9506) an exploratory analysis of 13 molecular markers in relation to clinical outcomes in 846 patients treated with fluorouracil (FU), or FU+irinotecan, or FU+oxaliplatin in a large UK-based randomized controlled trial (FOCUS - ASCO ’05 #3518). High TS IHC expression and tumor grade were highly significantly associated with reduced failure-free survival (FFS) in a multivariable model. We now present data from an independent validation set of 449 FOCUS patients and on the combined test and validation sets. Methods: Formalin-fixed, paraffin embedded blocks were retrieved from consenting patients and tissue microarrays made for IHC assessment. Factors assessed for the effect on FFS of first-line therapy were: liver metastases; ALP; grade; mucoid status; age; and IHC for dUTPase and TS. Log-rank univariate analyses and Cox Model multivariable analysis was performed. Results: Univariate analysis of the validation set failed to confirm evidence of the previously observed association between high TS expression and FFS (p=0.2); however high dUTPase IHC (p=0.01), ALP (p<0.0001) and grade (p=0.001) showed significant associations. Table 1 illustrates the results of univariate and multivariable analysis of the combined test and validation sets. In the Cox Model, high TS IHC expression, tumor grade and baseline serum ALP were highly significant predictors of reduced FFS. Conclusions: We failed to confirm a significant association between high TS expression and reduced FFS in an independent validation set. However, in an exploratory analysis of the combined validation and test sets (n>1000), TS IHC expression remained a highly significant predictor of FFS. Overall, our results cannot be taken to demonstrate a powerful and clinically useful influence of TS on treatment efficacy, but are consistent with a moderate effect.

[Table: see text]

No significant financial relationships to disclose.

[Endoscopic medialization with Vox implant: our experience]

OBJECTIVE

The purpose of this work is to analyze our preliminary results on the endoscopic vocal cords medialization by Bioplastique.

MATERIAL AND METHOD

This was a retrospective study on 39 cases of unilateral laryngeal paralysis, treated with the injection of Vox-implant between May 2004 and August 2006. The evolution of the swallowing disorders was followed by video fluoroscopy. The phoniatric evaluation was based on an auto evaluation questionnaire: Voice Handicap Index 10 (VHI-10).

RESULTS

Of the 19 patients who presented with swallowing disorder, 18 gave a normal video fluoroscopy test. In only one case, a second injection, one year later was necessary to completely cure the patient from fluid aspirations. Thirty two patients were satisfied with the post-operative vocal results. The Wilcoxon matched pairs test gave a statistically significant difference between pre and post-operative VHI-10 (p< 0,001). The voice handicap improved approximately 53%.

CONCLUSION

Bioplastic Vox-lmplant profits from a simple injection technique, it is well tolerated and gives a good voice quality. It allows moreover a fast and simple resolution of the problem, can be repeated, and in case of failure or insufficiency a thyroplasty remains possible.

Association between hormonal genetic polymorphisms and early-onset prostate cancer

We investigated the association between seven polymorphisms in four candidate genes involved in vitamin D and androgen metabolism with early-onset prostate cancer (CaP) risk. The polymorphisms were genotyped in 288 UK males who were diagnosed with CaP at the age of 55 y or younger and up to 700 population-based controls. An additional 50 cases (not selected for age) and 76 controls were also genotyped. Short (< or =22 repeats) AR (CAG)(n) repeats were associated with a significantly reduced risk of early onset CaP (OR 0.68, 95% CI 0.50-0.91) compared with men with long (> 22) repeats. Men homozygous for the leucine variant of SRD5A2 p.89V > L were also found to be at a significantly increased risk of CaP compared with men who were homozygous for the valine allele (OR 1.84, 95% CI 1.15-2.98). No associations were found with the AR (GGC)(n), CYP17 Msp A1 I, VDR Taq I, SRD5A2 (TA)(n) and p.49A >T polymorphisms and CaP risk. These findings suggest that common polymorphisms in the AR and SRD5A2 genes may be associated with early-onset CaP in British men.

The Relationship Between the Epidermal Growth Factor (EGF) 5′UTR Variant A61G and Melanoma/Nevus Susceptibility

The inheritance of a G allele in position 61 in the 5'UTR of the epidermal growth factor (EGF) gene has been reported to increase melanoma susceptibility, a finding we have investigated in this study. The most potent phenotypic risk factor for melanoma is the atypical mole syndrome (AMS) phenotype. Our hypothesis is that the AMS is genetically determined and that nevus genes are also low penetrance melanoma susceptibility genes. We report that the G allele frequencies were the same in 697 healthy women and 380 melanoma cases (OR 0.97, 95% CI 0.8-1.2 p=0.76). We therefore found no evidence that this polymorphism is a melanoma susceptibility gene. Furthermore, we found no evidence that the polymorphism controls the nevus phenotype (nevus number, number atypical nevi or AMS phenotype). We did find some evidence that the G allele may be associated with decreased tumor Breslow thickness (OR 0.5, 95% CI 0.3-0.9) for the A/A genotype versus A/G and G/G combined in tumors of thickness >3.5 vs < or =3.5 mm and may therefore act as a predictor of survival, although this finding is not in accord with the original report. This is the second study to find no association between EGF +61 and melanoma susceptibility.

Restriction in the usage of variable beta regions in T-cells infiltrating valvular tissue from rheumatic heart disease patients

Rheumatic Heart Disease (RHD) is a delayed consequence of a pharyngeal infection with group A streptococcus (GAS), usually ascribed to a cross-reactive immune response to the host's cardiac tissues. Several GAS proteins have been reported to be superantigens, also raising the possibility that T cells in RHD could be driven by superantigens. We therefore analysed the variable beta (V beta) repertoire of T cells infiltrating heart valves from chronic RHD patients undergoing elective valvular surgery. We analysed 15 valve specimens from patients with longstanding quiescent RHD and control valves from four non-rheumatic individuals. Total RNA was extracted from fresh valve tissue and employed to amplify 22 V beta genes by RT-PCR. In valvular tissue, a restricted number of only 2 to 9 V beta regions were detected as opposed to the findings in control valves. In 8 RHD valves, the expression of V beta1, 2, 3, 5.1, 7, 8, 9 or 14 was marked. These V beta regions have been related to GAS superantigens. Our results evidence the presence of a restricted set of T lymphocytes in valvular tissue from a majority of patients with chronic RHD and suggest that valvular sequelae in these patients might be related to a local antigen or superantigen driven inflammatory process that persists even many years after the initial triggering event.

Measuring the function of children with juvenile arthritis

OBJECTIVE

Juvenile idiopathic arthritis (JIA) can affect a child's performance across a range of activities necessary to normal childhood development. Although there are now several available measures of disability in JIA, none have been validated for use with children in the UK. Consequently, a study was undertaken to compare and validate four such measures, together with a locally developed function test.

METHODS

Fifty-three children between the ages of 5 and 16 yr were recruited into the study. The mean age was 10.4 yr and mean duration of disease 4 yr. Seventy per cent were female.

RESULTS

Internal consistency was adequate in three of five measures. Four of five measures showed the expected associations between disease activity and function (P<0.05). The level of reliability was poor for tests that involved direct assessment by therapists. Most showed poor levels of unidimensionality.

CONCLUSION

Until new measures become available, the CHAQ appears to be the current 'best buy' for measuring function in children with arthritis.

The Barthel Index and its relationship to nursing dependency in rehabilitation

OBJECTIVES

To investigate the clinical application of the Barthel Index as an indicator of nursing dependency in a younger disabled unit.

DESIGN

A prospective study of 132 patients (mean age 49) with chronic neurological problems.

SETTING

A younger disabled unit at a District General Hospital, Oxford.

MAIN OUTCOME MEASURES

The Barthel Index, and total nursing hours.

RESULTS

The Median Barthel Index was 7 (95% confidence interval 6-9). The mean nursing hours were 2.7 +/- 1.7 (CI 2.41-2.99). Spearman rank order correlation coefficient between the Barthel Index and nursing hours was r = -0.69 (CI -0.79 to -0.59).

CONCLUSIONS

Regression analysis showed that it was possible to use the Barthel Index as an indicator of nursing dependency particularly in physical care, and that it was independent of age and diagnosis.

Intralesional excision compared with en bloc resection for giant-cell tumors of bone

We reviewed the results for forty consecutively seen patients, each of whom had been managed by one surgeon for a giant-cell tumor of bone in an extremity between 1976 and 1990. Twenty patients had been managed with an en bloc resection and twenty, with an intralesional excision of the tumor with adjunctive local insertion of methylmethacrylate or phenol. All patients had been followed for a minimum of two years. Both en bloc resection and intralesional excision were found to be excellent oncological procedures. There were fewer complications and better functional results after the intralesional procedure than following the en bloc resection.

Importance of precise determination of technetium-labeled DISIDA concentrations for in vitro hepatocellular transport studies

Technetium 99m-labeled diisopropyliminodiacetic (acid [99mTc]DISIDA) has been used extensively in the evaluation of hepatobiliary diseases. As a result of investigation into transport mechanisms of [99mTc]DISIDA, we undertook to determine precise concentrations of this compound in the standard clinical formulation. Calculations based on published formulas were used. These take into account column efficiency, the time since the previous elution of 99mTc from the 99Mo column, and the total quantity of 99mTc eluted. Primary cultures of rat hepatocytes were used to evaluate the transport of Na99mTcO4 and the 99mTc-labeled DISIDA monomer. Pertechnetate was not taken up by the hepatocytes, the amount of [99mTc]DISIDa taken up was not dependent on the concentration of DISIDA but rather on the concentration of technetium, when the DISIDA/99mTc ratio was varied in the culture medium. We conclude that calculation of the total technetium concentration is necessary to determine the amount of compound taken up by the liver, and to interpret kinetic studies of hepatocellular transport mechanisms.

Quantitative biliary dynamics: introduction of a new noninvasive scintigraphic technique

We used a Tc-99m-labeled hepatobiliary agent to measure the partition of hepatic bile between gallbladder and intestine in sixteen normal patients and nine patients with cholelithiasis. In normal subjects, the fractions of the hepatic bile that flow into the gallbladder and the small intestine were widely variable, with mean values of 69 +/- 7% (s.e.) and 31 +/- 7% respectively. Bile reflux into the common hepatic duct was rare, occurring during the first 2/3 of the gallbladder ejection period and only when the ejection fraction was greater than 59%. The gallbladder's mean latent period, ejection period, ejection fraction, and ejection rate were 2 +/- 1 min, 11 +/- 1 min, 59 +/- 4%, and 5.9%/min respectively. In patients with cholelithiasis, the fraction of hepatic bile flowing into the gallbladder was normal, but the ejection fraction was significantly reduced (p less than 0.005). For an equivalent dose of cholecystokinin, the gallbladder in cholelithiasis is less responsive than in normal subjects.

Measurement of gallbladder emptying sequentially using a single dose of 99mTc-labeled hepatobiliary agent

The gallbladder emptying response to a single large (20 ng/kg) and four equally divided sequential small (5 ng/kg each) doses of octapeptide of cholecystokinin at 20-min intervals was measured in a paired study in six normal subjects noninvasively and quantitatively by a nongeometric method using a gamma camera, computer, and 99mTc-labeled hepatobiliary agent. The gallbladder mean (+/- SD) ejection fraction after a single large dose (20 ng/kg) of octapeptide of cholecystokinin was 34 +/- 24% and after four sequential small (5 ng/kg each) doses was 42 +/- 14%, 45 +/- 28%, 37 +/- 22%, and 32 +/- 27%, respectively (p greater than 0.05). The results of this study indicate that the first part of the 5 ng/kg sequential octapeptide of cholecystokinin dose is as effective as the single 20-ng/kg dose. The gallbladder emptying requires continued presence of high levels of octapeptide of cholecystokinin in the serum closer to levels that initiate contraction and in the absence of which the gallbladder ceases to empty further despite the fact it has inherent capacity to do so. Each of four equal octapeptide of cholecystokinin doses given sequentially elicits, on the average, an equal degree of emptying response. The method has potential for application in the study of the pharmacological effects of drugs on the biliary dynamics using a single dose of 99mTc-labeled hepatobiliary radiopharmaceutical.

Studies in Nitrogen-Cold Stabilized Polyphosphates

Wir präsentieren ein neues Verfahren für die Vorbereitung von PPO4-Vorrichtungen, die sich für 99mTc-Kennzeichnung eignen. Die von uns vorgeschlagene Methode benutzt die N2-Stabilisierung der Polyphosphat-Vorrichtung anstelle der Trockenfriermethode, über die berichtet wurde. Die auf diese Art vorbereiteten (N2-stabilisierten) Polyphosphat-Vorrichtungen zeigten eine chromatographische Bindungseffizienz zwischen 87 und 96% bei der Benutzung von Dünnschicht-Chromatographie mit verschiedenen Lösesystemen. In-vivo-Studien an Tieren zeigten für diese Methode eine 6wöchige Stabilität. Auch erscheint eine sehr gute Korrelation zwischen in-vitro-Bindeeffizienz und in-vivo-Wirksamkeit zu bestehen. Nachweislich kann PPO4 auf intravenösem, intramuskulärem oder intraperitonealem Wege zugeführt werden, wobei der Qualitätsunterschied der Studien gering ist.