Review of clinical outcomes of a cationic emulsion tear substitute in patients with dry eye disease

First-line options for the treatment of dry eye disease (DED) rely on artificial tears (ATs), among which cationic emulsion (CE)-based ATs have been developed in order to mimic the healthy tear film for an improved restoration of the ocular surface homeostasis. In this review, we describe the outcomes reported in several studies, assessing the mode of action, ocular tolerance and clinical performance of a CE-based AT. Pilot studies have revealed that CE-based ATs can increase the volume and stability of the tear film while limiting its evaporation rate. Larger studies have demonstrated that CE-based ATs play a significant role in the improvement of both objective and subjective DED parameters, including superior efficacy on DED symptoms compared to several other available AT formulation types. Concomitantly, CE-based ATs have been shown to help patients to prevent or recover from corneal defects associated with refractive surgery. These positive outcomes on ocular surface epithelia are likely due to the combination of unique rheological behaviour and intrinsic anti-inflammatory properties. Based on all clinical findings, CE-based ATs represent a valuable treatment option for patients with various etiologies of DED including evaporative forms and would deserve evaluation of benefits in other surgical intervention types triggering DED.

NOVATIVE: A Phase II/III, Multicenter, Double-masked, Randomized Study of Cyclosporine A 0.05% and 0.1% Ophthalmic Cationic Emulsion Versus Vehicle in Patients with Vernal Keratoconjunctivitis

PURPOSE

This study evaluates the efficacy and tolerability of cyclosporine A cationic emulsion (CsA-CE) in patients ≥4 years of age with moderate-to-severe vernal keratoconjunctivitis (VKC).

METHODS

This Phase II/III, multicenter, double-masked, dose-ranging study had 2 treatment periods: a 4-week, randomized, vehicle-controlled period in which patients received 0.05% CsA-CE, 0.1% CsA-CE, or vehicle eye drops 4 times daily (period 1) and a 3-month period in which patients received 0.05% CsA-CE or 0.1% CsA-CE 2 or 4 times daily (period 2). The primary efficacy end point was rating of subjective symptoms at day 28 in period 1 per the BenEzra scale.

FINDINGS

All groups showed improvement in subjective VKC symptoms at day 28, without a statistically significant difference between 0.05% or 0.1% CsA-CE vs vehicle. Both CsA-CE doses produced statistically significant improvements in corneal fluorescein staining scores vs vehicle at day 28; improvements were evident as early as week 1 and continued through month 1. Progressive reduction in subjective itching was evident after week 1 and continued through month 1. Treatment for an additional 3 months further improved subjective symptoms and objective signs of VKC in both CsA-CE groups. Improvement was most notable with 0.1% CsA-CE in patients with severe keratitis. The safety and tolerability profile is favorable.

IMPLICATIONS

Although treatment with 0.05% and 0.1% CsA-CE showed clinical efficacy in alleviating keratitis and itching as early as week 1, with sustained benefit through 1 month, the primary efficacy end point was not met. These findings informed the design of the Phase III trial of 0.1% CsA-CE (Vernal Keratoconjunctivitis Study).

CLINICALTRIALS

gov identifier: NCT00328653.

Topical cyclosporine A cationic ophthalmic emulsion in paediatric vernal keratoconjunctivitis: pooled analysis of randomised NOVATIVE and VEKTIS trials

BACKGROUND/OBJECTIVES

Cyclosporine A cationic ophthalmic emulsion (CsA CE) was evaluated in paediatric and adolescent patients with vernal keratoconjunctivitis (VKC) in the NOVATIVE (NCT00328653) and VEKTIS (NCT01751126) trials. The similarity of these studies permitted pooled assessment of the effect of CsA CE on corneal damage as well as safety and tolerability.

SUBJECTS/METHODS

Pooled outcomes were assessed for the first 28 days of treatment. In NOVATIVE, 118 patients were randomised to 4 times daily (QID) CsA CE 0.05%, 0.1%, or vehicle eye drops. In VEKTIS, 169 patients were randomised to CsA CE 0.1% QID or twice daily (BID) or vehicle. For these analyses, treatment groups comprised: (1) pooled CsA CE 0.1% QID arms (high-dose; n = 96); (2) pooled CsA CE 0.05% QID arm from NOVATIVE and CsA CE 0.1% BID data from VEKTIS (low-dose; n = 93); and (3) pooled vehicle QID arms (vehicle; n = 98).

RESULTS

Changes from baseline to day 28 (mean ± standard deviation) in corneal fluorescein staining (CFS) scores for CsA CE high-dose, low-dose, and vehicle groups were -1.6 ± 1.47 (95% CI: -0.9, -0.1; p = 0.0124 vs vehicle), -1.7 ± 1.39 (95% CI: -1.1, -0.3; p = 0.0015 vs vehicle), and -1.0 ± 1.55, respectively. Adverse events (AEs) of any type were reported in 37.5%, 34.4%, and 37.8% of the high-dose, low-dose, and vehicle groups, respectively. Most were mild or moderate in severity.

CONCLUSIONS

CsA CE significantly decreased corneal damage and was safe and well tolerated in patients with VKC. These data support CSA CE as a treatment option for the management of VKC.

Research priorities and identification of a health-service delivery model for psoriasis from the UK Psoriasis Priority Setting Partnership

BACKGROUND

Psoriasis impacts the health and psychosocial functioning of patients, conferring a significant economic burden on healthcare systems. There remain unmet needs in psoriasis care, which if addressed by research, could improve clinical outcomes.

AIM

To research priorities and identify a health service delivery model from the UK Psoriasis Priority Setting Partnership (PsPSP).

METHODS

Between July 2017 and November 2018, we invited people with lived experience of psoriasis and healthcare professionals to (i) identify unmet needs, and (ii) prioritize the order in which these should be addressed by research. We collaborated with the Psoriasis Association and used methodology established by the James Lind Alliance, which pioneers the joint setting of research priorities by patients and clinicians worldwide.

RESULTS

In our initial harvesting survey (Survey 1), 2133 questions were submitted by 805 individuals. Submissions that had not been answered by research (true uncertainties) were supplemented with evidence gaps from systematic reviews/guidelines published in the previous 5 years and refined to produce 55 indicative questions. Voting in Survey 2, by 1154 individuals, enabled a shortlist of questions, which were prioritized during the final workshop to produce a top 20 list of research questions. Submissions on health service delivery (5.8% of the total submissions), which were analysed separately, described a blueprint for psoriasis care.

CONCLUSIONS

The PsPSP will inform the translational research agenda, ensuring that future research is relevant for the needs of people with psoriasis and those who manage the disease. Submissions on health service delivery describe a model of holistic, patient-focused care providing high-quality, effective management for patients with psoriasis.

Cationic Emulsion-Based Artificial Tears as a Mimic of Functional Healthy Tear Film for Restoration of Ocular Surface Homeostasis in Dry Eye Disease

Dry eye disease (DED) is a complex multifactorial disease that affects an increasing number of patients worldwide. Close to 30% of the population has experienced dry eye (DE) symptoms and presented with some signs of the disease during their lifetime. The significant heterogeneity in the medical background of patients with DEs and in their sensitivity to symptoms renders a clear understanding of DED complicated. It has become evident over the past few years that DED results from an impairment of the ocular surface homeostasis. Hence, a holistic treatment approach that concomitantly addresses the different mechanisms that result in the destabilization of the tear film (TF) and the ocular surface would be appropriate. The goal of the present review is to compile the different types of scientific evidence (from in silico modeling to clinical trials) that help explain the mechanism of action of cationic emulsion (CE)-based eye drop technology for the treatment of both the signs and the symptoms of DED. These CE-based artificial tear (AT) eye drops designed to mimic, from a functional point of view, a healthy TF contribute to the restoration of a healthy ocular surface environment and TF that leads to a better management of DE patients. The CE-based AT eye drops help restore the ocular surface homeostasis in patients who have unstable TF or no tears.

Development patterns of necrophagous flies infesting rabbit carcasses decomposing in Mount Kapur Cave and its surrounding primary forest in Kuching, Sarawak

In addition to the scarcity of forensic entomology baseline data on oviposition of necrophagous insects and completion of their life cycles in the Borneo region, similar data derived from caves remain unreported. Since entomological baseline data can differ from one biogeoclimatic region to another, the lack of such data would limit the practical values of applying entomological evidence in estimating minimum postmortem interval (mPMI). Therefore, this present research that investigated oviposition and completion of life cycles of necrophagous flies infesting rabbit carcasses decomposing in Mount Kapur Cave and its surrounding forest habitat in Kuching, Sarawak merits forensic consideration. In general, 13 taxa of necrophagous flies were identified viz. Hypopygiopsis violacea, Hypopygiopsis fumipennis, Hemipyrellia ligurriens, Hemipyrellia tagaliana, Chrysomya megacephala, Chrysomya villeneuvi, Chrysomya rufifacies, Chrysomya chani, Chrysomya pinguis, Chrysomya nigripes, Ophyra spinigera and Ophyra chalcogaster, as well as unidentified Sarcophagidae. In addition, Hyp. violacea and Hyp. fumipennis were the two earlier necrophagous flies that oviposited in all rabbit carcasses decomposing in both habitats. While all these necrophagous flies were observed infesting carcasses in Mount Kapur Cave, Hem. ligurriens and Hem. tagaliana were not found infesting carcasses in the surrounding forest habitat. Complete life cycles for six and five different necrophagous fly species were successfully observed in Mount Kapur Cave and its surrounding forest habitat, respectively. Significant delay in oviposition, as well as longer durations for completing the life cycles in several necrophagous fly species were observed in Mount Kapur Cave when compared with those of surrounding forest habitat (p < 0.05). These findings deserve consideration as the first ever forensic empirical baseline data on oviposition and completion of life cycles for necrophagous flies in Sarawak as well as in a cave habitat, in view of its practical values for estimating mPMI for forensic practical caseworks.

Twelve-Month Results of Cyclosporine A Cationic Emulsion in a Randomized Study in Patients With Pediatric Vernal Keratoconjunctivitis

PURPOSE

To assess the safety and efficacy of cyclosporine A cationic emulsion (CsA CE) 0.1% eye drops in pediatric patients with severe active vernal keratoconjunctivitis (VKC).

DESIGN

Multicenter, double-masked, randomized controlled trial 8-month safety analysis.

METHODS

Of 169 patients (age range, 4-17 years) initially randomized in the 4-month VErnal KeratoconjunctiviTIs Study (VEKTIS), 142 entered the 8-month follow-up period during which CsA CE patients remained on their original regimen (CsA CE 4 times daily [QID, high-dose] or CsA CE twice daily [BID, low-dose] + vehicle BID) and vehicle patients were allocated to one of these 2 active regimens. Main outcome measures were safety, including treatment-emergent adverse events, and efficacy, including corneal fluorescein staining (CFS) score.

RESULTS

Improvements in CFS score, rescue medication use, key VKC symptoms (photophobia, tearing, itching, and mucous discharge), and quality of life (QoL) assessed by QUICK questionnaire observed with CsA CE compared with vehicle during the 4-month evaluation period remained stable during the 8-month follow-up period, with the high-dose regimen continuing to provide greater benefits in most efficacy measures. CsA CE was well tolerated. Treatment-related treatment-emergent adverse events during the 12-month study were reported in 15 (20.8%) and 11 (15.7%) of the CsA CE high-dose and low-dose patients, respectively, most commonly instillation site pain (13.9% and 7.1%, respectively). Laboratory data, vital signs, slit lamp examination, best-corrected distance visual acuity, and intraocular pressure raised no safety concerns.

CONCLUSIONS

Improvements in keratitis, symptoms, and QoL achieved after CsA CE treatment for 4 months remained stable over the 8-month follow-up period. CsA continued to maintain a favorable safety profile.

Paediatric vulval lichen sclerosus: a retrospective study

BACKGROUND

Lichen sclerosus (LS) is a chronic inflammatory dermatosis with a predilection for the anogenital region, which mainly affects prepubertal girls and postmenopausal women. The cause is unknown, but a number of potential aetiological factors have been identified.

AIM

To examine a cohort of patients with prepubertal-onset vulval LS (VLS) and assess baseline characteristics, clinical presentation, potential precipitating and predisposing factors, and response to treatment.

METHODS

Data were collected from case notes on patients aged < 18 years diagnosed with prepubertal-onset VLS attending a specialist vulval dermatology service. Data included clinical presentation, comorbidities, family history, therapy and response to treatment.

RESULTS

In total, 26 paediatric patients were identified. The median age at onset of symptoms was 5 years (range 2-8.5 years). Many previously identified potential aetiological factors for the development of VLS were identified, including family history, trauma, autoimmune disease and hormonal factors. A significant proportion of patients had a history of urinary tract symptoms, including incontinence and urinary tract infection. Most patients responded well to a standard course of induction topical therapy followed by maintenance therapy, but some, including three patients with ongoing urinary incontinence and three postpubertal patients, continued to have active disease.

CONCLUSION

A detailed assessment is essential in patients with VLS so that potential predisposing factors and comorbidities can be identified and managed. Urinary incontinence may be implicated in the development of paediatric VLS and may prevent adequate disease control. Paediatric VLS can persist through puberty, thus long-term follow-up is advised.

Efficacy and safety of 0.1% ciclosporin A cationic emulsion in dry eye disease: a pooled analysis of two double-masked, randomised, vehicle-controlled phase III clinical studies

BACKGROUND/AIM

To assess the treatment effect of 0.1% ciclosporin A cationic emulsion (CsA CE) versus vehicle on signs/symptoms of dry eye disease (DED) in various subgroups (moderate-to-severe DED/severe DED/Sjögren's syndrome (SS)/SS with severe DED).

METHODS

Pooled data were analysed from two similar phase III studies: SICCANOVE (moderate-to-severe DED) and SANSIKA (severe DED with severe keratitis). In both studies, patients aged ≥18 years received CsA CE 0.1% (n=395) or vehicle (n=339) once daily for 6 months. A composite responder efficacy endpoint (corneal fluorescein staining-Ocular Surface Disease Index (CFS-OSDI) at month 6) was used to evaluate the efficacy of CsA CE in alleviating signs/symptoms of DED (response defined as improvement of ≥2 grades in CFS and ≥30% in OSDI (baseline to month 6)). Human leucocyte antigen-DR (HLA-DR) conjunctival expression was used as a biomarker of ocular surface inflammation.

RESULTS

CsA CE-treated patients were significantly more likely to be CFS-OSDI responders than vehicle-treated patients in the overall (OR 1.66, 95% CI 1.11 to 2.50; P=0.015), severe DED (1.80, 1.04 to 3.19; P=0.038) and SS with severe DED (3.37, 1.20 to 11.19; P=0.030) populations. The difference was not significant for CsA CE versus vehicle for the overall Sjögren's population (OR 1.77, CI 0.89 to 3.66; P=0.109). CsA CE also significantly reduced median HLA-DR expression versus vehicle at 6 months (P=0.002).

CONCLUSION

Pooled phase III data indicate CsA CE produced significant improvement in signs/symptoms versus vehicle in patients with moderate-to-severe DED (especially in those with severe keratitis), including patients with SS with severe DED.

Persistence of Efficacy of 0.1% Cyclosporin A Cationic Emulsion in Subjects with Severe Keratitis Due to Dry Eye Disease: A Nonrandomized, Open-label Extension of the SANSIKA Study

PURPOSE

Results from a 6-month double-masked and a 6-month open-label study (SANSIKA) established the efficacy and safety of once-daily 0.1% cyclosporin A cationic emulsion (CsA CE) in severe keratitis due to dry eye disease (DED). This article presents results from the Post-SANSIKA study, a 24-month extension of SANSIKA assessing the sustained efficacy of CsA CE after treatment discontinuation.

METHODS

Time to relapse (corneal fluorescein staining [CFS] score ≥4 [modified Oxford scale]) was assessed after treatment discontinuation in patients from the SANSIKA study who had CFS improvement from a score of 4 to ≤2 after 6 or 12 months of treatment with CsA CE.

FINDINGS

Of 62 patients who achieved a CFS score ≤2 at the end of the SANSIKA study, 38 did not relapse and 24 (39%) relapsed during the 24-month period after CsA CE discontinuation; the latter (relapse) group comprised 35% of patients initially treated with CsA CE for 12 months in SANSIKA versus 47% of those treated for 6 months only. Patients spent the most time during the extension study at CFS scores of 1 or 2 (median duration of 8.5 weeks and 14.7 weeks per year, respectively), indicating marked improvement, and less time at scores of 3, 4, or 5 (median time, 2.0 weeks, 0 weeks, and 0 weeks per year). Of 23 patients eligible for safety analysis (ie, patients who received the study treatment at least once), 12 (52.2%) reported a total of 26 ocular adverse events (AEs). Among these, 5 ocular AEs, reported in 5 patients (21.7%), were considered related to study treatment: 3 events of mild instillation site pain in 3 patients (13.0%) and eye discharge and foreign body sensation, each reported in 1 patient (4.3%). Only 1 systemic AE (nasal congestion), reported in 1 patient (4.3%), was considered related to study treatment. None of the AEs led to treatment discontinuation.

IMPLICATIONS

The majority of patients who discontinued CsA CE after experiencing DED improvement in the SANSIKA study did not experience a relapse in this 24-month follow-up study; these patients spent the most time at CFS scores consistent with marked improvement. CsA CE had a favorable safety/tolerability profile over 2 years. Treatment for up to 12 months with CsA CE provides sustained improvements in patients with severe keratitis due to DED. EudraCT registration no. 2012-002066-12.

Influence of citronella and chlorpyrifos on Chrysomya megacephala (Fabricius) and Chrysomya rufifacies (Macquart) (Diptera: Calliphoridae) infesting rabbit carcasses

Influence of citronella and chlorpyrifos on oviposition and duration for completing life cycles for Chrysomya megacephala and Chrysomya rufifacies infesting decomposing rabbit carcasses was studied. Male rabbit carcasses (n = 12) were equally divided into control, citronella- and chlorpyrifos-treated groups, and left to decompose for 14 consecutive days. C. megacephala was the first necrophagous fly oviposited in all control and citronellatreated carcasses followed by C. rufifacies. Although initial oviposition of C. megacephala was delayed (4-6 hours) in citronella-treated carcasses (P andlt; 0.05), prolongation in completing its life cycle was not observed. Neither delayed initial oviposition nor prolonged life cycle for C. rufifacies in citronella-treated carcasses was observed. Oviposition was delayed for chlorpyrifos-treated carcasses (0.42 g/L), and eclosion of eggs remained unsuccessful. The findings deserve consideration because these chemicals are easily accessible and can be used by cunning criminals to confuse forensic entomologists while estimating minimum postmortem interval.

Topical ocular 0.1% cyclosporine A cationic emulsion in dry eye disease patients with severe keratitis: experience through the French early-access program

Purpose

The objective of this study was to report the evaluation of efficacy and safety of cyclosporine A cationic emulsion (CsA CE) 0.1% for the treatment of severe keratitis in adults with dry eye disease (DED) in a French early-access program.

Methods

Patients with DED and severe keratitis (corneal fluorescein staining [CFS] score of 3-5 on the Oxford scale and/or the presence of corneal lesions [filaments or ulcers]) were enrolled in a compassionate use program (Authorization for Temporary Use [ATU]) for once-daily CsA CE, which was approved by French health authorities prior to its registration. Efficacy and safety at 1, 3, 6, and 12-month follow-up visits were evaluated.

Results

The ATU cohort (n=1,212; mean age =60.5 years; 79.5% female; 98.1% with severe keratitis; 74.5% with corneal lesions) consisted of 601 CsA-naïve patients and 611 patients treated previously with other CsA formulations. The primary DED etiology was Sjögren's syndrome (48.7%). Clinical benefit could be discerned among 548 evaluable patients from months 1 to 12: keratitis improvement, 44.8% at month 1 and 42.1% at month 12; keratitis stabilization, 47.2% and 45.7%, respectively; symptom improvement, 47.2% and 48.6%; and symptom stabilization, 44.8% and 45.0%. Corneal clearing (CFS score =0) increased from 4.8% (month 1) to 11.4% (month 12). No unexpected safety concerns were identified; instillation site pain (10.2%) and eye irritation (7.8%) were the most common adverse events.

Conclusion

The French ATU cohort provides supportive data on the clinical benefit of CsA CE in improving/stabilizing symptoms and corneal damage in DED patients with severe keratitis in real-world clinical practice.

Correlation Between the Inflammatory Marker HLA-DR and Signs and Symptoms in Moderate to Severe Dry Eye Disease

Purpose

To investigate correlations of the inflammatory HLA-DR marker with clinical signs and symptoms commonly used to assess dry eye disease (DED) severity.

Methods

Baseline data were collected from three clinical studies conducted on moderate to severe DED patients. Characteristics of DED were analyzed and correlations were performed in 311 patients. Data were analyzed after treatment with 1 mg/mL cyclosporine (CsA) and vehicle. We quantified HLA-DR by flow cytometry in impression cytology specimens.

Results

We found HLA-DR significantly increased with diagnosis of Sjögren syndrome (P < 0.0001) and meibomian gland disease (P = 0.0223). The strongest significant correlation was seen with the corneal fluorescein staining (CFS, r = 0.30, P < 0.0001). Significant negative relationships were also found with Schirmer's test (r = -0.20, P = 0.0003) and tear break-up time (TBUT, r = -0.13, P = 0.0226). Correlations were statistically significant with total Ocular Surface Disease Index and visual analog scale scores (r = 0.12, P = 0.0426, and r = 0.14, P= 0.0176, respectively). We found HLA-DR arbitrary units of fluorescence were statistically reduced after CsA treatment compared to vehicle (P = 0.022 and P = 0.021 in two studies).

Conclusions

In clinical research on DED, discrepancy is often observed between symptoms and signs. We found HLA-DR correlated significantly with CFS clinical signs and to a lower extent Schirmer's test and weakly with TBUT and symptom reporting questionnaires. HLA-DR was reported to be useful for monitoring anti-inflammatory efficacy treatments in DED, which was confirmed with the reduction of HLA-DR while on CsA treatment. Its expression by conjunctival cells has the potential to serve as a biomarker, bridging signs and symptoms in clinical research in DED, but there is still a need for additional validation studies.

Ovulation rate and early embryonic survival rate in female rabbits of a synthetic line and a local Algerian population

<p>A higher litter size at birth has been reported in female rabbits from a Synthetic line than in those of the Local Algerian population. The aim of this work was to analyse whether this difference in litter size was due to a higher ovulation rate and/or embryonic survival rate in Synthetic line than in Local Algerian population. In total, 24 multiparous female rabbits from Synthetic line and 23 from Local population were used in this experiment. Litter size at birth was recorded up to the first 3 parities. Litter size was 20% higher in Synthetic line than Local population. At their 4th gestation, the females were euthanized at 72 h post coitum. Synthetic line females had 50% more ova and embryos than those of Local population (+4.42 ova and +3.92 embryos, respectively). Synthetic line displayed a lower percentage of normal embryos and a larger number of unfertilized oocytes than Local population (–2.81% and +0.64 oocytes, respectively), but differences were not relevant. Synthetic line showed a lesser embryonic stage of development at 72 h post coitum, showing a higher percentage of early morulae (31.50 vs. 8.50%) and a lower percentage of compact morulae (51.45 vs. 78.65%) than Local population. No relevant difference was found for early embryonic survival rate between Synthetic line and Local population. In conclusion, the difference in litter size was mainly due to a higher ovulation rate in the Synthetic line, allowing more embryos to develop in this line.</p>

A diagnostic challenge

A 74 year-old woman presented with a 9 month history of a slowly enlarging exophytic lesion over her left nasal alar. Examination revealed a firm, cystic mass fixed to underlying skin. It was pedunculated with occasional superficial telangiectasia and a violaceous hue. A differential diagnosis of dermoid or sebaceous cyst, dermatofibroma, and neurofibroma was considered. Histopathological examination confirmed the rare diagnosis of chondroid syringoma (CS), which has a reported incidence of 0.01- 0.098% of excised skin tumors. It is unusual for CS to present in an elderly woman, as these benign primary skin tumors normally present in adult males. Dermoscopy does not reveal any specific features and the diagnosis is difficult to make based on clinical examination alone.

Sago Waste Based Activated Carbon Film as an Electrode Material for Electric Double Layer Capacitor

In this feasibility study a novel prospective electrode material for electric double layer capacitors (EDLC) has been investigated. This promising material is activated carbon (AC) film produced using sago waste as a precursor. Important parameters of the technological process are the KOH to charcoal ratio and the content of the polytetrafluoroethylene (PTFE) binder. The influence of these parameters on the microtexture and pore structure and on the electrochemical characteristics of the AC films has been studied in detail. The measured specific surface area (SSA) of the samples is in the range from 212 to 1498 m2/g. It has been found that the presence of micropores increases the specific capacity while the presence of the mesopores acts in the opposite direction, because these mesopores are too wide in diameter for aqueous electrolyte. The specific capacitance of the studied samples has been found to be in the range from 16 to 64 F/g.

The genetic basis of congenital hyperinsulinism

Congenital hyperinsulinism (CHI) is biochemically characterised by the dysregulated secretion of insulin from pancreatic beta-cells. It is a major cause of persistent hyperinsulinaemic hypoglycaemia (HH) in the newborn and infancy period. Genetically CHI is a heterogeneous condition with mutations in seven different genes described. The genetic basis of CHI involves defects in key genes which regulate insulin secretion from beta-cells. Recessive inactivating mutations in ABCC8 and KCNJ11 (which encode the two subunits of the adenosine triphosphate sensitive potassium channels (ATP sensitive K(ATP) channels)) in beta-cells are the most common cause of CHI. The other recessive form of CHI is due to mutations in HADH (encoding for-3-hydroxyacyl-coenzyme A dehydrogenase). Dominant forms of CHI are due to inactivating mutations in ABCC8 and KCNJ11, and activating mutations in GLUD1 (encoding glutamate dehydrogenase) and GCK (encoding glucokinase). Recently dominant mutations in HNF4A (encoding hepatocyte nuclear factor 4alpha) and SLC16A1 (encoding monocarboxylate transporter 1) have been described which lead to HH. Mutations in all these genes account for about 50% of the known causes of CHI. Histologically there are three (possibly others which have not been characterised yet) major subtypes of CHI: diffuse, focal and atypical forms. The diffuse form is inherited in an autosomal recessive (or dominant manner), the focal form being sporadic in inheritance. The diffuse form of the disease may require a near total pancreatectomy whereas the focal form requires a limited pancreatectomy potentially curing the patient. Understanding the genetic basis of CHI has not only provided novel insights into beta-cell physiology but also aided in patient management and genetic counselling.

Social consumption of alcohol in adolescents with Type 1 diabetes is associated with increased glucose lability, but not hypoglycaemia

AIM

To determine the effects of social consumption of alcohol by diabetic adolescents on glycaemic control.

METHODS

Fourteen (five male) patients aged > 16 years were recruited from the diabetes clinic at the Royal Children's Hospital. The continuous glucose monitoring system (CGMS) was attached at a weekend when alcohol consumption was planned for one night only. For each patient, the 12-h period from 18.00 h to 06.00 h for the night with alcohol consumption (study period) was compared with the same period with non-alcohol consumption (control period) either 24 h before or after the alcohol study night. Thus, each subject was his/her own control. Glycaemic outcomes calculated from continuous glucose monitoring included mean blood glucose (MBG), percentage of time spent at low glucose levels (CGMS < 4.0 mmol/l), normal glucose levels (CGMS 4.0-10.0 mmol/l) and high glucose levels (> 10.0 mmol/l) and continuous overall net glycaemic action (CONGA).

RESULTS

The mean number of standard alcohol drinks consumed during the study period was 9.0 for males and 6.3 for females. There was no difference in percentage of time at high and normal glucose levels in the study and control periods. During the control period, there was a higher percentage of time with low glucose levels compared with the study period (P < 0.05). There was an increased level of glycaemic variation during the study time when compared with the control period.

CONCLUSIONS

In an uncontrolled, social context, moderately heavy alcohol consumption by adolescents with Type 1 diabetes appears to be associated with increased glycaemic variation, but not with low glucose levels.

Dexamphetamine use for management of obesity and hypersomnolence following hypothalamic injury

Unrelenting weight gain, morbid obesity and disturbance of the sleep-wake cycle are well-recognized sequelae of hypothalamic injury. These health problems and their risk of significant associated co-morbidity drive the search for potential treatment modalities.

OBJECTIVE

To report effects on weight change and wakefulness in a cohort of 12 patients with structural hypothalamic lesions treated with low-dose dexamphetamine.

METHOD

Retrospective review of case notes.

RESULTS

Twelve patients received dexamphetamine 5 mg twice daily (median duration 13 months in males, 15 months in females). Ten of 12 patients experienced either stabilisation of weight or weight loss on treatment (median loss -0.7 SDS in males, -0.44 SDS in females). Eleven patients reported improvement in daytime wakefulness and/or concentration and exercise tolerance.

CONCLUSION

Low-dose dexamphetamine therapy has a positive impact on inexorable weight gain and daytime somnolence following hypothalamic injury.

Ethnic differences in catechol O-methyltransferase pharmacogenetics: frequency of the codon 108/158 low activity allele is lower in Kenyan than Caucasian or South-west Asian individuals

Catechol O-methyltransferase (COMT) inactivates neurotransmitters, hormones and drugs such as levodopa. COMT activity is inherited in an autosomal recessive manner and individuals with low activity have thermolabile COMT protein. A low activity allele has been demonstrated at codon 108/158 of the soluble and membrane bound COMT protein, respectively, whereby a G to A transition results in a valine to methionine substitution, rendering the protein more thermolabile. As ethnic differences in erythrocyte COMT activity have been previously demonstrated, the frequency of low activity alleles were investigated in 265 British Caucasian, 99 British South-west Asian and 102 Kenyan individuals. Genotyping of COMT codon 108/158 was performed using a minisequencing method. Erythrocyte COMT activity was measured in 60 British Caucasian individuals by radiochemical assay. The frequency of low activity alleles was 0.54 in Caucasians, 0.49 in South-west Asians, and 0.32 in Kenyans. There was a much lower frequency of individuals with homozygous low activity allele in the Kenyan population (9%) than in Caucasians (31%) or South-west Asians (27%). Erythrocyte COMT activity was lower and less thermostable in individuals with homozygous low activity alleles. The data provide molecular evidence that low COMT is less common in African individuals than the Caucasian population.