Development of a cost-effective diagnostic algorithm incorporating transcription factor immunohistochemistry in the evaluation of pituitary tumours

PURPOSE

To determine the utility of the 2022 WHO Classification of pituitary tumours in routine clinical practice and to develop an optimal diagnostic algorithm for evaluation of tumour type in a real-world setting.

METHODS

Retrospective evaluation of pituitary tumour immunohistochemistry (IHC), operatively managed at St Vincent's Hospital Sydney, between 2019 and 2021. Routine IHC comprised evaluation of transcription factors [steroidogenic factor 1 (SF1), T-box transcription factor 19 (TPIT) and pituitary-specific positive transcription factor (PIT1)] and anterior pituitary hormones. Three tiered algorithms were tested, in which hormone IHC was performed selectively based on the initial transcription factor results. These were applied retrospectively and compared with current practice 'gold standard' comprising all transcription factor and hormone IHC. Diagnostic accuracy and cost were evaluated for each.

RESULTS

There were 113 tumours included in the analysis. All three algorithms resulted in 100% concordance with the 'gold standard' in the characterisation of tumour lineage. While all three were associated with relative cost reduction, Algorithm #3, which omitted hormone IHC in the setting of positive SF1 or TPIT and performed IHC for growth hormone, prolactin and thyroid stimulating hormone only in the setting of PIT1 positivity, was the most cost-efficient. Additionally, there were 12/113 tumours with no distinct cell lineage.

CONCLUSION

A diagnostic algorithm omitting hormone IHC except in cases of PIT1 positivity is an accurate and cost-effective approach to diagnose the type of pituitary tumour. A significant subgroup of pituitary tumours with no distinct cell lineage, frequently plurihormonal, remains difficult to classify with the new WHO criteria and requires further evaluation.

Identification of Distinct Long COVID Clinical Phenotypes Through Cluster Analysis of Self-Reported Symptoms

Background

We aimed to describe the clinical presentation of individuals presenting with prolonged recovery from coronavirus disease 2019 (COVID-19), known as long COVID.

Methods

This was an analysis within a multicenter, prospective cohort study of individuals with a confirmed diagnosis of COVID-19 and persistent symptoms >4 weeks from onset of acute symptoms. We performed a multiple correspondence analysis (MCA) on the most common self-reported symptoms and hierarchical clustering on the results of the MCA to identify symptom clusters.

Results

Two hundred thirty-three individuals were included in the analysis; the median age of the cohort was 43 (interquartile range [IQR], 36–54) years, 74% were women, and 77.3% reported a mild initial illness. MCA and hierarchical clustering revealed 3 clusters. Cluster 1 had predominantly pain symptoms with a higher proportion of joint pain, myalgia, and headache; cluster 2 had a preponderance of cardiovascular symptoms with prominent chest pain, shortness of breath, and palpitations; and cluster 3 had significantly fewer symptoms than the other clusters (2 [IQR, 2–3] symptoms per individual in cluster 3 vs 6 [IQR, 5–7] and 4 [IQR, 3–5] in clusters 1 and 2, respectively; P < .001). Clusters 1 and 2 had greater functional impairment, demonstrated by significantly longer work absence, higher dyspnea scores, and lower scores in SF-36 domains of general health, physical functioning, and role limitation due to physical functioning and social functioning.

Conclusions

Clusters of symptoms are evident in long COVID patients that are associated with functional impairments and may point to distinct underlying pathophysiologic mechanisms of disease.

A multi-site study on the impact of an advance care planning workshop on attitudes, beliefs and behavioural intentions over a 6-month period

BACKGROUND

This study evaluated the impact of the adapted version of the Respecting Choices® The Living Matters Advance Care Planning (ACP) facilitator training programme on trainees' attitudes on facilitation 6 months post-training.

SETTING AND PARTICIPANTS

Two hundred and twenty-one healthcare professionals consisting of doctors, nurses, medical social workers from different training venues in Singapore participated in the first phase of the study (pre- and post) of which 107 participated in the second phase 6 months later (follow-up).

METHODS

Participants self-rated their attitudes, beliefs and behavioural intentions through surveys at three time points in an evaluation design that utilised repeated measures one-way ANOVA (pre-, post-, follow-up). Between-group differences were also examined using independent t-test.

RESULTS

At follow-up, mean scores increased significantly in understanding, confidence, and competence. Changes in effect sizes were large. Although trainees continued to think that ACP is emotionally draining for facilitators, more than before, facilitation experience was considered pleasant for themselves with the positive change significant and moderate in effect size. Those who had experience completing/initiating ACP significantly held more positive views than those who did not.

CONCLUSIONS

The ACP facilitator training programme had lasting effects on enhancing the understanding, competence, and confidence of trainees. Importantly, findings showed that experience in actual facilitation within 6 months after training was important and giving trainees opportunities to facilitate is recommended.

Effect of varietal attributes on the adoption of an orange-fleshed sweetpotato variety in Upper East and Northern Ghana

Despite sustained economic growth and reduction in some of forms of malnutrition, Ghana still faces a national prevalence rate of 20.8% vitamin A deficiency (VAD) among for children 6-59 months old. Orange-fleshed sweetpotato (Ipomoea batatas L.) (OFSP) can significantly improve vitamin A intake and contribute toward reducing VAD, especially in Northern Ghana where VAD is 31% among young children. Several poverty and nutrition projects in Ghana have promoted the use of OFSP for its health benefits. This study assesses the effect of three varietial attributes on adoption of the first released OFSP variety in Northern Ghana namely, Apomuden. The study concluded that sweetness, taste and dry matter have joint significant effects on adoption of an OFSP variety. The positive and negative traits highlighted will inform the on-going breeding effort.

P43 Parasellar capillary haemangioma with intrasellar extension

Objectives

Capillary haemangioma is a benign vascular tumour that typically arises from skin and mucosal surfaces at birth and in infants. Central nervous system (CNS) capillary haemangioma in adults is extremely rare. We describe a case of capillary haemangioma located within the parasellar region extending into the sella.

Design

Case report.

Results

We report a 64-year-old patient who presented with a short history of ptosis and left sided headaches. CT showed a 3 cm by 2.5 cm para-sellar lesion extending into the sella. MRI showed a homogenously hyperintense lesion on T2-weighted MRI and FLAIR, which was isointense with adjacent brain parenchyma on T1-weighted MRI. This lesion also demonstrated contrast enhancement. The patient underwent an initial endoscopic transsphenoidal biopsy, which was inconclusive, followed by a craniotomy and debulking. Histological examination revealed fibrous tissue containing numerous thin walled and irregular vascular channels of varying sizes. There was a mild associated inflammatory infiltrate, mainly formed of small mononuclear chronic inflammatory cells, and occasional histiocytes. The histological appearances were in keeping capillary haemangioma.

Conclusions

The present case describes a capillary haemangioma located in the sella. The rarity of this vascular entity and the absence of any pathognomonic imaging features make it difficult to diagnose based on radiological appearances alone. Although rare, CH should be a differential when considering a sella or parasellar lesion.

Transmission of HIV Drug Resistance and the Predicted Effect on Current First-line Regimens in Europe

Transmitted human immunodeficiency virus drug resistance in Europe is stable at around 8%. The impact of baseline mutation patterns on susceptibility to antiretroviral drugs should be addressed using clinical guidelines. The impact on baseline susceptibility is largest for nonnucleoside reverse transcriptase inhibitors.

Background. Numerous studies have shown that baseline drug resistance patterns may influence the outcome of antiretroviral therapy. Therefore, guidelines recommend drug resistance testing to guide the choice of initial regimen. In addition to optimizing individual patient management, these baseline resistance data enable transmitted drug resistance (TDR) to be surveyed for public health purposes. The SPREAD program systematically collects data to gain insight into TDR occurring in Europe since 2001.

Methods. Demographic, clinical, and virological data from 4140 antiretroviral-naive human immunodeficiency virus (HIV)–infected individuals from 26 countries who were newly diagnosed between 2008 and 2010 were analyzed. Evidence of TDR was defined using the WHO list for surveillance of drug resistance mutations. Prevalence of TDR was assessed over time by comparing the results to SPREAD data from 2002 to 2007. Baseline susceptibility to antiretroviral drugs was predicted using the Stanford HIVdb program version 7.0.

Results. The overall prevalence of TDR did not change significantly over time and was 8.3% (95% confidence interval, 7.2%–9.5%) in 2008–2010. The most frequent indicators of TDR were nucleoside reverse transcriptase inhibitor (NRTI) mutations (4.5%), followed by nonnucleoside reverse transcriptase inhibitor (NNRTI) mutations (2.9%) and protease inhibitor mutations (2.0%). Baseline mutations were most predictive of reduced susceptibility to initial NNRTI-based regimens: 4.5% and 6.5% of patient isolates were predicted to have resistance to regimens containing efavirenz or rilpivirine, respectively, independent of current NRTI backbones.

Conclusions. Although TDR was highest for NRTIs, the impact of baseline drug resistance patterns on susceptibility was largest for NNRTIs. The prevalence of TDR assessed by epidemiological surveys does not clearly indicate to what degree susceptibility to different drug classes is affected.

Characterization of RIPK3-mediated phosphorylation of the activation loop of MLKL during necroptosis

Mixed lineage kinase domain-like pseudokinase (MLKL) mediates necroptosis by translocating to the plasma membrane and inducing its rupture. The activation of MLKL occurs in a multimolecular complex (the 'necrosome'), which is comprised of MLKL, receptor-interacting serine/threonine kinase (RIPK)-3 (RIPK3) and, in some cases, RIPK1. Within this complex, RIPK3 phosphorylates the activation loop of MLKL, promoting conformational changes and allowing the formation of MLKL oligomers, which migrate to the plasma membrane. Previous studies suggested that RIPK3 could phosphorylate the murine MLKL activation loop at Ser345, Ser347 and Thr349. Moreover, substitution of the Ser345 for an aspartic acid creates a constitutively active MLKL, independent of RIPK3 function. Here we examine the role of each of these residues and found that the phosphorylation of Ser345 is critical for RIPK3-mediated necroptosis, Ser347 has a minor accessory role and Thr349 seems to be irrelevant. We generated a specific monoclonal antibody to detect phospho-Ser345 in murine cells. Using this antibody, a series of MLKL mutants and a novel RIPK3 inhibitor, we demonstrate that the phosphorylation of Ser345 is not required for the interaction between RIPK3 and MLKL in the necrosome, but is essential for MLKL translocation, accumulation in the plasma membrane, and consequent necroptosis.

FZD7 drives in vitro aggressiveness in Stem-A subtype of ovarian cancer via regulation of non-canonical Wnt/PCP pathway

Ovarian cancer (OC) can be classified into five biologically distinct molecular subgroups: epithelial-A (Epi-A), Epi-B, mesenchymal (Mes), Stem-A and Stem-B. Among them, Stem-A expresses genes relating to stemness and is correlated with poor clinical prognosis. In this study, we show that frizzled family receptor 7 (FZD7), a receptor for Wnt signalling, is overexpressed in the Stem-A subgroup. To elucidate the functional roles of FZD7, we used an RNA interference gene knockdown approach in three Stem-A cell lines: CH1, PA1 and OV-17R. Si-FZD7 OC cells showed reduced cell proliferation with an increase in the G0/G1 sub-population, with no effect on apoptosis. The cells also displayed a distinctive morphologic change by colony compaction to become more epithelial-like and polarised with smaller internuclear distances and increased z-axis height. Immunofluorescence (IF) staining patterns of pan-cadherin and β-catenin suggested an increase in cadherin-based cell–cell adhesion in si-FZD7 cells. We also observed a significant rearrangement in the actin cytoskeleton and an increase in tensile contractility in si-FZD7 OC cells, as evident by the loss of stress fibres and the redistribution of phospho-myosin light chain (pMLC) from the sites of cell–cell contacts to the periphery of cell colonies. Furthermore, there was reciprocal regulation of RhoA (Ras homolog family member A) and Rac1 (Ras-related C3 botulinum toxin substrate 1 (Rho family, small GTP-binding protein Rac1)) activities upon FZD7 knockdown, with a significant reduction in RhoA activity and a concomitant upregulation in Rac1 activity. These changes in pMLC and RhoA, as well as the increased TopFlash reporter activities in si-FZD7 cells, suggested involvement of the non-canonical Wnt/planar cell polarity (PCP) pathway. Selected PCP pathway genes (cadherin EGF LAG seven-pass G-type receptor 3 (CELSR3), prickle homolog 4 (Drosophila) (PRICKLE4), dishevelled-associated activator of morphogenesis 1 (DAAM1), profilin 2 (PFN2), protocadherin 9 (PCDH9), protocadherin α1 (PCDHA1), protocadherin β17 pseudogene (PCDHB17), protocadherin β3 (PCDHB3), sprouty homolog 1 (SPRY1) and protein tyrosine kinase 7 (PTK7)) were found to be more highly expressed in Stem-A than non Stem-A subgroup of OC. Taken together, our results suggest that FZD7 might drive aggressiveness in Stem-A OC by regulating cell proliferation, cell cycle progression, maintenance of the Mes phenotype and cell migration via casein kinase 1ɛ-mediated non-canonical Wnt/PCP pathway.

Ministry of health clinical practice guidelines: cancer screening

The Ministry of Health publishes national clinical practice guidelines to provide doctors and patients in Singapore with evidence-based guidance on managing important medical conditions. This article reproduces the introduction and executive summary (with key recommendations from the guidelines) from the Ministry of Health clinical practice guidelines on cancer screening, for the information of readers of the Singapore Medical Journal. Chapters and page numbers mentioned in the reproduced extract refer to the full text of the guidelines, which are available from the Ministry of Health website (http://www.moh.gov. sg/mohcorp/publications.aspx?id=24018). The recommendations should be used with reference to the full text of the guidelines. Following this article are multiple choice questions based on the full text of the guidelines.

Vitamin D induces innate antibacterial responses in human trophoblasts via an intracrine pathway

The active form of vitamin D, 1,25-dihydroxyvitamin D (1,25(OH)(2)D), is a potent inducer of the antimicrobial protein cathelicidin, CAMP (LL37). In macrophages this response is dependent on intracrine synthesis of 1,25(OH)(2)D from precursor 25-hydroxyvitamin D (25OHD), catalyzed by the enzyme 25-hydroxyvitamin D-1alpha-hydroxylase (CYP27B1). In view of the fact that trophoblastic cells also express abundant CYP27B1, we postulated a similar intracrine pathway for induction of CAMP in the placenta. Analysis of placenta explants, primary cultures of human trophoblast, and the 3A trophoblastic cell line treated with 1,25(OH)(2)D (1-100 nM) revealed dose-dependent induction of CAMP similar to that observed with primary cultures of human macrophages. Also consistent with macrophages, induction of trophoblastic CAMP was enhanced via intracrine conversion of 25OHD to 1,25(OH)(2)D. However, in contrast to macrophages, induction of CAMP by vitamin D in trophoblasts was not enhanced by costimulation with Toll-like receptor ligands, such as lipopolysaccharide. Despite this, exposure to vitamin D metabolites significantly enhanced antibacterial responses in trophoblastic cells: 3A cells infected with Escherichia coli showed decreased numbers of bacterial colony-forming units compared with vehicle-treated controls when treated with 25OHD (49.6% +/- 10.9%) or 1,25(OH)(2)D (45.4% +/- 9.2%), both P < 0.001. Treatment with 25OHD (1-100 nM) or 1,25(OH)(2)D (0.1-10 nM) also protected 3A cells against cell death following infection with E. coli (13.6%-26.9% and 22.3%-40.2% protection, respectively). These observations indicate that 1,25(OH)(2)D can function as an intracrine regulator of CAMP in trophoblasts, and may thus provide a novel mechanism for activation of innate immune responses in the placenta.

Screening for distress in cancer patients: is the distress thermometer a valid measure in the UK and does it measure change over time? A prospective validation study

A prospective validation study was conducted in 171 consenting patients from oncology and palliative care outpatient clinics to validate the Distress Thermometer (DT) against the Hospital Anxiety and Depression Scale (HADS), General Health Questionnaire-12 (GHQ-12) and Brief Symptom Inventory-18 (BSI-18) at baseline, four weeks and eight weeks. Receiver Operating Characteristic analysis was used to examine the sensitivity and specificity of the DT scores against the clinically significant cut-off scores of the criterion measures reporting 95% confidence intervals. Standardised response means were used to compare DT scores with criterion measures over time. For a cut-off of 4 vs 5, sensitivity against HADS was 79%, specificity 81%; against GHQ-12, sensitivity was 63%, specificity 83%; and against BSI-18, sensitivity was 88%, specificity 74%. At both four and eight weeks, DT scores tended to change significantly in the same direction as the criterion measures. Ninety-five percent of patients found completing the DT acceptable. The DT is valid and acceptable for use as a rapid screening instrument for patients in the UK with cancer. Our results indicate that it can be used to monitor change in psychological distress over time, but further work is needed to confirm this.

The use of complementary therapy by men with prostate cancer in the UK

The study aims were to determine the use of complementary therapies (CT) by men with prostate cancer, and to explore factors influencing CT use and attitudes toward CT use. A cross-sectional survey design was used in which a postal questionnaire was mailed to an eligible sample of 405 patients with prostate cancer receiving outpatient treatment in a London teaching hospital. The primary outcomes were the prevalence of CT use and the relationship between CT use and mental health status. Two hundred and ninety-four patients (73%) responded, of whom 25% were using CT. The most frequently used CTs were vitamins, low-fat diets, lycopene and green tea. Multivariate analyses revealed no differences in mental health scores between CT users and non-users. CT users were younger (OR 0.93, 95% CI 0.89-0.97) and were more likely to be receiving conservative management in the form of 'active surveillance' (OR 5.23, 95% CI 1.78-15.41) compared with non-users. Over half of the participants (55%) wanted to learn more about CT. Forty-three per cent of CT users had not informed any doctor about their CT use. Clinicians need to be aware of the prevalence of CT use amongst patients with prostate cancer, considering the potential harm that could be caused by interactions with conventional treatments.

Metabolic acidosis in the critically ill: part 2. Causes and treatment

The correct identification of the cause, and ideally the individual acid, responsible for metabolic acidosis in the critically ill ensures rational management. In Part 2 of this review, we examine the elevated (corrected) anion gap acidoses (lactic, ketones, uraemic and toxin ingestion) and contrast them with nonelevated conditions (bicarbonate wasting, renal tubular acidoses and iatrogenic hyperchloraemia) using readily available base excess and anion gap techniques. The potentially erroneous interpretation of elevated lactate signifying cell ischaemia is highlighted. We provide diagnostic and therapeutic guidance when faced with a high anion gap acidosis, for example pyroglutamate, in the common clinical scenario 'I can't identify the acid--but I know it's there'. The evidence that metabolic acidosis affects outcomes and thus warrants correction is considered and we provide management guidance including extracorporeal removal and fomepizole therapy.

Importation of Polish trichinellosis cases to Ireland, June 2007

A Polish national in his late 20s presented in June to the emergency department of a hospital in Dublin.

A Phase II study of 3-aminopyridine-2-carboxaldehyde thiosemicarbazone (3-AP) and gemcitabine in advanced pancreatic carcinoma. A trial of the Princess Margaret hospital Phase II consortium

3-Aminopyridine-2-carboxaldehyde thiosemicarbazone (3-AP, Triapine, Vion Pharmaceuticals, New Haven, CT) is an inhibitor of the M2 subunit of ribonucleotide reductase (RR). Preclinical testing demonstrates synergy between 3-AP and gemcitabine. Phase I studies of the combination have suggested tolerability and some initial evidence of efficacy. Therefore, a phase II study of gemcitabine plus 3-AP in advanced pancreatic carcinoma was undertaken. In this two-step phase II trial, patients with advanced pancreatic adenocarcinoma who had not received prior chemotherapy for advanced disease were treated with 3-AP 105 mg/m(2) given over 2 h. Four hours after the 3-AP infusion was completed, gemcitabine 1,000 mg/m(2) was given over 30 min. Both drugs were given on days 1, 8 and 15 of a 28-day cycle.Twenty-six patients were enrolled to the study. One patient withdrew consent prior to receiving any treatment and is excluded from all further analyses. Four patients discontinued treatment due to adverse effects. Grade 3/4 hematological adverse events included neutropenia, thrombocytopenia, lymphopenia, leukopenia and anemia and the most frequent non-hematological adverse events were fatigue and pain. No objective responses were observed. Eleven patients had stable disease (SD). In five of these eleven patients, SD lasted for more than 6 months. The median time to progression was 4.1 months and the 6 month progression-free survival rate was 29%. The median survival was 9.0 months with a 1-year survival of 28.0%. The combination of 3-AP and gemcitabine is associated with moderate toxicity in patients with advanced pancreatic cancer. This two-stage trial was stopped after stage I due to lack of antitumour activity. On the basis of this clinical trial, the combination of gemcitabine and 3-AP at this dose and schedule does not warrant further study in this patient population.

Inhibition of poly (ADP-ribose) polymerase (PARP) by ABT-888 in patients with advanced malignancies: Results of a phase 0 trial

3518

Background: Inhibition of PARP activity sensitizes tumor cells to the effects of DNA damaging agents. We conducted a phase 0 pharmacokinetic (PK) and pharmacodynamic (PD) study of ABT-888, an oral inhibitor of PARP. Methods: The objectives were to determine a dose range at which ABT-888 inhibits PARP in tumor tissue and in peripheral blood mononuclear cells (PBMC); and the PK of ABT-888. Patients with advanced solid tumors refractory to at least one line of therapy were eligible; patients with CLL or follicular lymphomas were also eligible if standard therapy was not currently indicated. A single oral dose of ABT-888 was administered per patient, dose escalations were planned in cohorts of 3 patients each (10 mg, 25 mg, 50 mg, 100 mg, and 150 mg). PBMC and tumor sampling were performed before and after drug administration for real time PK and PD analyses. All patients underwent PBMC sampling; tumor biopsies were planned once significant inhibition of PARP activity in PBMCs was seen in 1 of 3 patients in a cohort or plasma Cmax of 210 nM was achieved in at least 1 patient. Tumor biopsies were performed at baseline in the week prior to drug administration and then 3–6 hours post drug administration. Significant inhibition of PARP activity was defined as at least 0.69 reduction on the log scale, which also satisfied statistical significance. Results: A total of 6 patients have been studied so far, 3 each for the 10 mg and 25 mg cohorts. No treatment related adverse events have been observed. Target Cmax was exceeded in the first cohort, all patients in the next cohort underwent tumor biopsies in addition to PBMC sampling. A trend towards inhibition of PARP activity in PBMCs was observed in the first cohort. Significant inhibition of PAR levels was observed in tumor biopsies from all 3 patients in the second cohort (92%, 99%, 100% reductions respectively, as compared to baseline). Greater than 85% reduction of PAR levels was observed in PBMCs from 2 of the 3 patients in the second cohort (one patient was not evaluable). Conclusions: ABT-888 is orally bioavailable and inhibits PARP activity in PBMCs and tumor cells. Target assay feasibility was established in human samples. Funded in part by NCI Contract N01-CO-12400

No significant financial relationships to disclose.

Statistical considerations for a phase 0 trial

14038

Background: Phase ‘0’ clinical trials are small first in man studies to determine a dose or dose range which results in a desired biologic effect. Novel statistical designs are needed due to the limited number of patients and the complexities of analyzing primary pharmacodynamic endpoints. Methods: In general, the effect of the agent will be evaluated, based on a biologic endpoint(s), at two levels, the individual participant level (for a given dose amount), and the agent dose amount level (across individual participants). At the participant level, the effect is preferably defined as a dichotomous outcome. The statistical criteria should be such that the threshold is not surpassed with more than .10 probability, for a given participant, at a given dose amount, for the null hypothesis case of no true biologic effect. At the dose amount level, the effect rate is defined as the probability that a randomly chosen participant will satisfy the participant level threshold. The statistical criteria for declaring an observed effect rate to be significant should be such that the over-all probability of declaring the agent effective (summed across all dose amounts) should not exceed .10 for the null hypothesis case of no true biologic effect. A target effect rate, measured across participants, should be given, and the power to detect it, for a given dose amount, should be estimated. Ideally, there will be multiple pre-agent administration endpoint measurements, per participant, to define variability. Examples: 1. If 10 participants are accrued to a single dose amount, an observed effect rate for that dose amount could be defined to be significant if at least 2 of the 10 participants satisfy the participant threshold, yielding 85–90% power to detect a 35% effect rate. 2. If 5 participants are accrued to each of 2 dose amounts, an observed effect rate for a particular dose amount could be defined to be significant if at least 2 of the 5 participants satisfy the participant threshold, yielding approximately 90% power to detect a 60% effect rate. 3. If 3 participants are accrued to each of 4 dose amounts, an observed effect rate for a particular dose amount could be defined to be significant if at least 2 of the 3 participants satisfy the participant threshold, yielding approximately 90% power to detect an 80% effect rate.

No significant financial relationships to disclose.

The Dundee University Scottish Keratoconus study: demographics, corneal signs, associated diseases, and eye rubbing

AIM

To investigate and correlate the corneal, refractive, topographic and familial characteristics of a large cohort with keratoconus.

METHODS

Prospective observational study of 200 consecutive patients presenting with keratoconus during the 4 year-period 1997-2000. Subjects were examined at enrolment and at a final review. Data were collected on demographic characteristics, referral route, symptoms, refractive correction, eye rubbing, family history, medical history, slit-lamp biomicroscopic corneal signs, and computerized corneal topography.

RESULTS

Mean age at enrolment was 30.9+/-10.4 (range, 12.2-72) years (N=200, 62.5% male, 93% white Caucasian) with a 5% family history of keratoconus. Atopic diseases included asthma (23%), eczema (14%), and hay fever (30%). Only 9% wore contact lenses before referral. Mean follow-up was 1004 days +/-282 (range, 390-1335) and 9.7+/-8.9 (range, 1.1-60) years from diagnosis. The mean simulated K1 corneal power at enrolment was 51.74+/-5.36 (range, 42.59-67.32) D and 88.5% exhibited bilateral keratoconus. Fifty-three (15%) topographically confirmed cones exhibited no clinical corneal signs at presentation. At enrollment, 56% had a pachymetry <0.480 mm increasing to 77% at final review. Forty-eight percent of subjects reported significant eye rubbing and there was a highly statistically significant difference (two sample t-test P=0.018) between keratoconus and control groups. TMS-2 axial corneal power was strongly associated with corneal scarring and age at diagnosis. The size of the scarring effect was 2.2 D (95% confidence interval (CI) 1.34, 3.06).

CONCLUSIONS

This study provides an overview of a large population with keratoconus highlighting presenting features and clinical and topographic progression over a 4 year-period.

Control of an outbreak of multi-drug-resistant Acinetobacter baumannii in an intensive care unit and a surgical ward

We describe an outbreak of multi-drug-resistant Acinetobacter baumannii (MRAB) that occurred in an intensive care unit (ICU) and a surgical ward from December 2003 to March 2004. Mapping patient movements on a timeline indicated that the outbreak was confined to these two areas. Investigation by the hospital's infection prevention service found that a possible source of spread was improper cleaning methods used on respiratory equipment. Pulsed-field gel electrophoresis analysis of available isolates indicated the presence of two distinct strains. One strain was seen in patients from the ICU and the other strain was seen in the surgical ward patients. Cleaning and environmental decontamination as well as staff education were implemented to halt further immediate spread. The deficiencies identified during the investigation were also resolved. The final outcome was the successful termination of this outbreak.

Prospective evaluation of somatic and autonomic small fibers in selected autonomic neuropathies

BACKGROUND

There are a number of distal and generalized small-fiber neuropathies. The neuropathologic basis is poorly understood as somatic and autonomic C fibers are not usually studied in the same region of the body.

OBJECTIVE

To evaluate prospective somatic and autonomic C-fiber function in 11 healthy control subjects and 38 patients with different clinical patterns of neuropathy.

METHODS

Distal small-fiber neuropathy (DSFN), peripheral neuropathy (PN), diabetic neuropathy (DN), neuropathic postural tachycardia syndrome (POTS), and idiopathic autonomic neuropathy (IAN) were evaluated. Intraepidermal nerve fiber density was used to evaluate distal somatic C fibers. Both quantitative sudomotor axon reflex test and skin norepinephrine content were measured for the biopsy site to assess distal autonomic C-fiber function. Postganglionic sudomotor, adrenergic, and cardiovagal functions were evaluated by autonomic reflex testing and quantified using a Composite Autonomic Severity Scale.

RESULTS

Skin norepinephrine concentration was significantly related to CASS. DN was associated with somatic and autonomic C-fiber impairment with good agreement. POTS was associated with selective distal autonomic deficit. DSFN had combined distal somatic and C-fiber impairment. IAN showed combined and selective distal and generalized autonomic C-fiber impairment. The somatic neuropathies had C-fiber impairment affecting both populations to varying degrees.

CONCLUSION

Although a general agreement exists between the loss of somatic C fibers and autonomic deficits, selective involvement occurs for specific autonomic neuropathies.